peace river manasota regional water supply ......authority’s reservoir system for maintaining raw...

PEACE RIVER MANASOTA REGIONAL WATER SUPPLY AUTHORITY BOARD OF DIRECTORS MEETING

August 5, 2020

REGULAR AGENDA ITEM 4

Water Quality Master Plan Status Update

______________________________________________________________________________ Presenter - Richard Anderson, System Operations Manager Stephanie Ishii, Hazen & Sawyer Drew Coleman, Hazen & Sawyer Recommended Action - Motion to receive and file ‘Peace River Manasota

Regional Water Supply Authority Water Quality Master Plan’ (Hazen and Sawyer; May 1, 2020).

Development of a Water Quality Master Plan (WQMP) is identified in the Authority’s Strategic Plan and was approved as a line item in the FY 2019 budget. Maintaining and expanding regional and local water supply connectivity promotes resilience and reliability in the region. This connectivity can also present challenges associated with maintaining the quality of drinking water delivered through a supply system carrying and mixing waters of differing character. Understanding the character and distribution of these water quality differences, the potential issues associated with mixing of such waters, and identifying means and methods to maintain excellent water quality in Regional and Authority Customer local water supply systems is the goal of the WQMP. On October 3, 2018 the Authority Board approved a Work Order to Hazen and Sawyer Inc. to complete the 2020 WQMP for a budget amount not to exceed $174,010. This Plan is intended to be a companion document to the 2020 Integrated Regional Water Supply Plan. The WQMP was completed in early May 2020 and provides a focus on the items listed below:

• Review the current regional water quality provided to Authority Customers including recommendations for continued production and delivery of regional supply that meets regulatory and Customer needs;

• Review regional system and Customer facility/system water quality and provide guidance on treatment strategies/methods for water quality improvements;

• Treatment strategies to meet future regulatory requirements;

• Recommendations for establishing regional water quality standards for water input into and delivered through the regional system, and;

• WQMP conclusions and next steps. This status update will document the final conclusions, recommendations and next steps identified by Hazen and Sawyer. Staff recommends that the Board accept the 2020 Water Quality Master Plan Final Report. The Executive Summary section from the WQMP is attached under “Tab A” along with a thumb drive containing an Adobe pdf file of the entire report. Attachments: Tab A Presentation Materials Tab B 2020 Water Quality Master Plan - Executive Summary and electronic copy of Final Report

TAB A Regular 4 – Presentation Materials

1

Peace River Manasota Regional Water Supply Authority Water Quality Master Plan PresentationAugust 5, 2020 Board Meeting

Water Quality Master Plan Approach

Evaluation of Source and

Finished Water Quality

Regulatory Review / Risk AssessmentWater

Quality Master

Plan Evaluation / Optimization of

Operations

Evaluation of Treatment

Enhancements

Water quality data compilation using business intelligence tools

Regulatory review (existing and future) and risk assessment for existing treatment barriers

Regional corrosion control evaluationReview of regional water quality standards

Evaluation of future treatment options (improved total organic carbon removal)

2

1

2

2

Compliant Today, Prepared for Tomorrow

Compliant with existing Federal and State water quality requirements

Proactively preparing for potential changes in finished water quality standards

Lead and Copper Rule (LCR) changes will impact utilities

3

Evaluation of Source and

Finished Water Quality

Regulatory Review / Risk Assessment

Recommendations for Additional Sampling

4

Constituent Sampling Location Sampling Time

UCMR4 algal toxins Source and finished water During algae events

Strontium Source and finished water Wet and dry season

Perchlorate Source and finished water Wet and dry season

Chlorate Source and finished water Wet and dry season

Nitrosamines Finished water and distributed water DBP sampling schedule

Manganese Source and finished water Seasonally

Per- and polyfluoroalkyl substances (PFAS) Source and finished water Wet and dry season

3

4

3

Corrosion Control is Successfully Practiced throughout the Regional System

5

Evaluation / Optimization of

Operations

• Various corrosion control strategies practiced throughout the region

• All customers comply with existing lead and copper requirements

• Considered future changes to water supply interfaces

Potential Corrosion Control Modifications for Future Conditions

6

Individual strategies

Regional approach

Uniform conditions

Operational simplicity

No mixing zones

Local optimization

Successful track record

Low capital cost


Operations

5

6

4

Findings for Corrosion Control Evaluation

7


Operations

• No changes to corrosion control are recommended at this time

• Monitor Long-Term Lead and Copper Rule Revisions

• Increase local understanding of blending challenges and opportunities as regional system expands

Recommended Approach forRegional Water Quality Standards

8


Operations

Current Approach:

Meet State and Federal Requirements at each Point of Connection

Action Response Plan

Water Supply Contract

Potential Future Approach:

Specific water quality requirements between Authority and customers

• Less prescriptive• Low initial investment• Creates communication avenues• High personnel cost per event

• Contractually defined water quality• Likely to increase shared cost

because of treatment requirements• Doesn’t facilitate communication

Maintain Status Quo:

Meet State and Federal Requirements at each Point of Connection

7

8

5

Recommended Water Quality Data Collection at POCs

Parameter On-line Grab Sample

Chloramine/Free Ammonia Residual

Nitrite Weekly

Nitrate Weekly

pH

Alkalinity Weekly

TOC Weekly

DBPs Weekly

Color Weekly

Hardness (T and Ca) Weekly

Turbidity

Pb/Cu Weekly

Conductivity/TDS

9

TOC Removal was Evaluated because of Treatment and Finished Water Quality Implications

Total organic carbon (TOC)

Chemical demand

Disinfectant stability

FlushingTaste and odor

Disinfection byproduct formation

10


Enhancements

0

10

20

30

40

50

60

70

80

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

TT

HM

s, µ

g/L

Fin

ish

ed

Wa

ter

TO

C,

mg

C/L

TOC

TTHMs

9

10

6

Findings for TOC Evaluation

• TOC removal is currently excellent• Increased TOC removal is not required under current conditions

• Potential future drivers may warrant additional TOC removal• Operational and distribution system challenges

• Source water quality changes

• Regulatory changes

• Options for increased TOC removal • Optimized river water withdrawals, based on quantity and quality

• Optimized treatment

• Treatment enhancements

11


Enhancements

Summary and Next Steps

11

12

7

Summary

Peace River Facility is meeting required water quality regulations and goals

Authority’s reservoir system benefits water supply and quality

PRF provides consistent water quality to the customers• PRF achieves excellent TOC removal

Customers are meeting the current lead and copper rule requirements• Blending interfaces in the distribution system will change

Regional water quality standards may be beneficial

Water quality considerations are a critical component of water supply planning

13

Next Steps

• Increase water quality monitoring at sources and points of connection

• Continue to use water quality to optimize river water withdrawals and reservoir management

• Continue to monitor regulatory updates, especially Lead and Copper Rule

• Continue to monitor drivers for increased TOC removal

• Obtain consensus on regional water quality standards

• Integrate water quality modeling into future water supply planning

14

13

14

8

Questions

15

TAB B 2020 Water Quality Master Plan - Executive Summary and electronic copy of Final Report

Hazen and Sawyer

1000 N Ashley Drive, Suite 1000

Tampa, FL 33602 • 813.630.4498

Peace River Manasota Regional

Water Supply Authority Water

Quality Master Plan Final Report May 1, 2020

Peace River Manasota Regional Water Supply Authority May 1, 2020

Water Quality Master Plan

Final Report

| Table of Contents i

Table of Contents

Executive Summary ........................................................................................................ 1

Section 1. Background ................................................................................................. 1-1

1.1 Water Quality Master Plan Objectives and Organization ....................................... 1-4

Section 2. Regulatory Review and Outlook for Drinking Water Quality ........................ 2-1

2.1 Existing Federal Regulatory Requirements ........................................................... 2-1

2.1.1 Surface Water Treatment Rules .............................................................. 2-2

2.1.2 Total Coliform Rule and the Revised Total Coliform Rule ....................... 2-3

2.1.3 Disinfection Byproduct Rules ................................................................... 2-4

2.1.4 Lead and Copper Rule ............................................................................ 2-4

2.1.5 Radionuclides .......................................................................................... 2-5

2.1.6 Arsenic Rule ............................................................................................ 2-5

2.1.7 Filter Backwash Recycling Rule .............................................................. 2-5

2.1.8 The Water Infrastructure Act of 2018 ...................................................... 2-6

2.2 Potential Future Regulatory Requirements and Guidelines ................................... 2-6

2.2.1 Process for Identifying New Constituents to Regulate and/or Limit via

Guidelines 2-6

2.2.1.1 Unregulated Contaminant Monitoring Rule (UCMR) and Contaminant

Candidate List (CCL) ............................................................................... 2-7

2.2.1.2 Health Advisory Levels .......................................................................... 2-10

2.2.2 Potential Federal Regulatory Updates .................................................. 2-11

2.2.2.1 Algal Toxins ........................................................................................... 2-11

2.2.2.2 Strontium ............................................................................................... 2-12

2.2.2.3 Perchlorate and Chlorate ....................................................................... 2-12

2.2.2.4 Volatile Organic Compounds ................................................................. 2-13

2.2.2.5 Nitrosamines and Emerging Disinfection Byproducts ........................... 2-13

2.2.2.6 Manganese ............................................................................................ 2-14

2.2.2.7 Chromium VI .......................................................................................... 2-15

2.2.2.8 Trace Organic Compounds ................................................................... 2-15

2.2.2.9 Microbial Constituents ........................................................................... 2-16

2.2.2.10 Per- and Polyfluoroalkyl Substances ...................................... 2-16



Final Report

| Table of Contents ii

2.2.2.11 Long-term Lead and Copper Rule Revisions.......................... 2-17

2.2.2.12 Potable Reuse Regulations ......................................................... 2-20

2.3 PRF Hazard Analysis and Critical Control Point (HACCP) Evaluation ................ 2-22

2.3.1 Finished Water Quality Targets ............................................................. 2-22

2.3.2 Treatment Efficacies .............................................................................. 2-24

2.3.3 HACCP Matrix Applications ................................................................... 2-24

Section 3. Current Conditions in the Peace River Manasota Regional Water Supply

System ........................................................................................................ 3-1

3.1 Historical Data Review using Business Intelligence Tools ..................................... 3-1

3.2 Water Quality Baseline ........................................................................................... 3-1

3.2.1 Finished Water Quality Compliance Summary ........................................ 3-1

3.2.2 Raw Water Quality and Variability ........................................................... 3-7

3.2.3 Disinfection Byproduct Formation.......................................................... 3-10

3.2.4 Disinfectant Residual ............................................................................. 3-12

3.2.5 Unregulated Contaminant Monitoring Rule Results .............................. 3-13

3.2.6 Newly Collected Water Quality Data for the Water Quality Master Plan ... 3-

16

3.3 Operational Baseline ............................................................................................ 3-26

3.3.1 Source Water Withdrawal Protocols ...................................................... 3-26

3.3.1.1 Peace River Withdrawals ...................................................................... 3-26

3.3.1.2 Aquifer Storage and Recovery .............................................................. 3-27

3.3.2 Disinfection Protocols ............................................................................ 3-27

Section 4. Treatment Evaluation for Additional TOC Removal at PRF ........................ 4-1

4.1 Drivers for Additional TOC Removal ...................................................................... 4-1

4.2 Preliminary Treatment Assumptions ...................................................................... 4-2

4.3 TOC Target ............................................................................................................ 4-4

4.4 Options for Additional TOC Removal ..................................................................... 4-5

4.4.1 Granular Activated Carbon Treatment at the PRF .................................. 4-6

4.4.1.1 Description ............................................................................................... 4-6

4.4.2 Ozone-Biofiltration at the PRF ................................................................. 4-7

4.4.2.1 Description ............................................................................................... 4-7

4.4.3 Magnetic Ion Exchange (MIEX) at the PRF ............................................ 4-9



Final Report

| Table of Contents iii

4.4.3.1 Description ............................................................................................... 4-9

4.5 Estimated Opinion of Probable Construction Costs ............................................. 4-10

4.6 Cost / Benefit Analysis ......................................................................................... 4-11

Section 5. Corrosion Control Evaluation ...................................................................... 5-1

5.1 Drivers for Corrosion Control Evaluation................................................................ 5-1

5.2 Current System-Wide Practices ............................................................................. 5-1

5.3 Water Quality Impacts of Current System-Wide Practices .................................... 5-2

5.3.1 Blending ................................................................................................... 5-3

5.3.2 Compatibility ............................................................................................ 5-6

5.4 Regional Corrosion Control Strategy Discussion ................................................... 5-8

5.5 Recommendations ................................................................................................. 5-9

Section 6. Regional Water Quality Standards Evaluation ............................................ 6-1

6.1 Examples ................................................................................................................ 6-1

6.1.1 Metropolitan Water District of Southern California Action Response Plan 6-

1

6.1.2 San Francisco Public Utilities Commission Action Response Plan......... 6-2

6.1.3 Tampa Bay Water Supply Contract ......................................................... 6-3

6.2 Authority Implications ............................................................................................. 6-4

Section 7. Conclusions and Next Steps ....................................................................... 7-1



Final Report

| Table of Contents iv

List of Tables

Table ES-1: Potential Future Regulations of Concern .................................................................... 2

Table ES-2: Conceptual GAC System Cost Estimate..................................................................... 6

Table ES-3: Conceptual O3-BAC System Cost Estimate ............................................................... 6

Table ES-4: Payback Periods for 50% and 75% Reduction of Flushing ........................................ 7

Table ES-5: Water Quality Standards Approach Comparison ....................................................... 8

Table 2-1: Cyanotoxins to be Sampled under UCMR4 ............................................................... 2-9

Table 2-2: HAAs, Bromide, and TOC Required to be Sampled under UCMR4......................... 2-9

Table 2-3: Additional Constituents to be Sampled Under UCMR 4 ......................................... 2-10

Table 2-4: USEPA Health Advisory Levels for Cyanotoxins in Drinking Water ..................... 2-11

Table 2-5: Summary of State PFAS Regulations ...................................................................... 2-17

Table 2-6: Estimated Costs for Centralized Orthophosphate Treatment Systems ..................... 2-19

Table 2-7: Florida Administrative Code Chapter 62 Regulatory Summary .............................. 2-21

Table 2-8: Sources of Finished Water Quality Targets in the Authority HACCP Matrix ......... 2-23

Table 2-9: Anticipated Removal Efficiencies of Treatment Barriers at the PRF ...................... 2-24

Table 3-1: Water Quality Criteria for Microorganisms ............................................................... 3-2

Table 3-2: Water Quality Criteria for Disinfectants and Disinfection Byproducts ..................... 3-3

Table 3-3: Water Quality Criteria for Inorganic Chemicals ........................................................ 3-3

Table 3-4: Water Quality Criteria for Organic Chemicals ........................................................... 3-4

Table 3-5: Water Quality Criteria for Radionuclides .................................................................. 3-7

Table 3-6: UCMR 4 Sampling Schedule by Agency ................................................................. 3-14

Table 3-7: Summary of Existing Authority UCMR 4 Results as of October 2019 ................... 3-14

Table 3-8: Natural Organic Matter Parameters Summary ......................................................... 3-19

Table 3-9: Excitation-Emission Matrix Raw Water Test Results .............................................. 3-22

Table 3-10: Inorganic Water Quality Parameters Summary ...................................................... 3-25

Table 3-11: Customer Disinfection Trimming Protocols .......................................................... 3-28

Table 4-1: Summary of Customer Flushing Data ........................................................................ 4-1

Table 4-2: Sampling Results Summary ....................................................................................... 4-4

Table 4-3: Specific DBP Analysis Results .................................................................................. 4-4

Table 4-4: Proposed GAC Treatment Process Summary ............................................................ 4-7

Table 4-5: Proposed O3-BAC Treatment Process Summary ...................................................... 4-9

Table 4-6: Conceptual GAC System Cost Estimates ................................................................. 4-11

Table 4-7: Conceptual O3-BAC System Cost Estimate ............................................................. 4-11

Table 4-8: Payback Periods for 50% and 75% Reduction of Flushing...................................... 4-12

Table 5-1: Historical Copper Data ............................................................................................... 5-2

Table 5-2: Historical Lead Data ................................................................................................... 5-3

Table 5-3: Peace River Interconnections ..................................................................................... 5-7

Table 5-4: Customer Interconnections ......................................................................................... 5-8

Table 6-1: Distribution System Total Chlorine Residual Response ............................................ 6-2

Table 6-2: SFPUC Water Quality Action Levels for Notification .............................................. 6-3

Table 6-3: Tampa Bay Water – Exhibit D Water Quality Parameters ........................................ 6-3

Table 6-4: Water quality standards approach comparison ........................................................... 6-4

Table 6-5: Suggested water quality data at POCs ........................................................................ 6-5

Table 7-1: Sampling Recommendations to Prepare for Potential Future Regulatory Changes ... 7-2



Final Report

| Table of Contents v

List of Figures

Figure 1-1: Peace River Manasota Regional Water Supply Authority and Customer Distribution

System ...................................................................................................................... 1-2

Figure 1-2: Peace River Facility Process Flow Diagram ............................................................. 1-3

Figure 2-1: Timeline for the Development of Drinking Water Rules in the United States ......... 2-2

Figure 2-2: RRA Deadlines for Systems Depending on the Size of the Population Served ....... 2-6

Figure 2-3: Federal Safe Drinking Water Act Standard Setting Process ..................................... 2-8

Figure 2-4: Timeline of Lead and Copper Rule Amendments and Revisions ........................... 2-18

Figure 3-1: TDS Concentrations in Raw River and Reservoir (Pond) Water .............................. 3-8

Figure 3-2: TDS Concentrations in Raw Reservoir (Pond) Water .............................................. 3-8

Figure 3-3: Color Concentrations in Raw River and Reservoir (Pond) Water ............................ 3-9

Figure 3-4: Total Hardness Concentrations in Raw Reservoir (Pond) Water ........................... 3-10

Figure 3-5: TOC (top) Disinfectant Byproduct (bottom) Concentrations in Finished Water.... 3-11

Figure 3-6: Trihalomethane Concentrations in Finished Water and at Points of Connection ... 3-12

Figure 3-7: Disinfectant (as Cl2) Concentrations in Finished Water and at Points of Connection

(top) and TOC Concentrations in Finished Water (bottom) ................................... 3-13

Figure 3-8: Disinfection Byproduct Formation Potential Test Results ..................................... 3-17

Figure 3-9: Chloramine Decay Test Results .............................................................................. 3-18

Figure 3-10: a) TOC, b) UV254, and c) SUVA254 Concentrations Across the PRF System... 3-21

Figure 3-11: Raw Water FRI Results......................................................................................... 3-24

Figure 3-12: Treated Water FRI Results .................................................................................... 3-25

Figure 3-13: TOC Concentrations in Reservoir (Pond) Water .................................................. 3-27

Figure 4-1: Specific DBP Formation Potential Analysis ............................................................. 4-5

Figure 4-2: Process Flow Diagram for GAC Alternative ............................................................ 4-7

Figure 4-3: Ozone-BAC Process Flow Diagram ......................................................................... 4-8

Figure 4-4: MIEX Process Flow Diagram ................................................................................... 4-9

Figure 5-1: Current Customer Corrosion Control Strategies ....................................................... 5-2

Figure 5-2: HDR Hydraulic Model Water Source Blending in 2020 .......................................... 5-4

Figure 5-3: HDR Hydraulic Model Water Source Blending in 2040 .......................................... 5-5

List of Appendices

Appendix A: Peace River Facility Hazard Analysis and Critical Control Point Matrix

Appendix B: Authority and Customer Data Request

Appendix C: Water Quality Baseline (Power BI file)

Appendix D: Sampling Plan Protocol for the Water Quality Master Plan



Final Report

| Table of Contents vi

List of Acronyms

Abbreviation Definition

AADF Annual average daily flow

ASR Aquifer Storage and Recovery

AWIA America’s Water Infrastructure Act

CCL Contaminant Candidate List

CCR Consumer Confidence Report

CEC Referred to as contaminants of emerging concern

CFS Cubic feet per second

DBP Disinfection by-products

DBPFP Disinfection byproduct formation potential

ECHO Enforcement and Compliance History Online

EEM Excitation-emission matrix

ERP Emergency Response Plan

FBRR Filter Backwash Recycling Rule

FDEP Florida Department of Environmental Protection

FDOH Florida Department of Health

GAC Granular activated carbon

HAA Haloacetic Acids

HAAFP HAA formation potential

HACCP Hazard Analysis and Critical Control Point

HAL Health advisory levels

IESWTR Interim Enhanced Surface Water Treatment Rule

LCR Lead and Copper Rule

LSL Lead service line

LSLR Lead Service Line Replacement

MCL Maximum Contaminant Level

MCLG Maximum contaminant level goal

MFL Minimum flows and levels

MIEX Magnetic ion exchange

MRDL Maximum Residual Disinfectant Levels

NDWAC National Drinking Water Advisory Council

NIRS National Inorganics and Radionuclides Survey

NOM Natural organic matter

NPDWR National Primary Drinking Water Rules

O&M Operation & Maintenance

PAC Powdered activated carbon

POU Point of use

PRC Potable Reuse Commission

PRF Peace River Facility



Final Report

| Table of Contents vii

Abbreviation Definition

RO Reverse Osmosis

RRA Risk and Resilience Assessment

SDWA Safe Drinking Water Act

SW Surface water

SWFWMD Southwest Florida Water Management District

SWTR Surface Water Treatment Rule

TCR Total Coliform Rule

TDS Total dissolved solids

THM Trihalomethanes

THMFP THM formation potential

TOC Total organic carbon

TT Treatment Technique

UCMR Unregulated Contaminant Monitoring Rule

USEPA United States Environmental Protection Agency

VOC Volatile organic compounds

WQMP Water Quality Master Plan

WQP Water quality parameter



Final Report

| Executive Summary ES-1

Executive Summary

Background

The Peace River Manasota Regional Water Supply Authority (Authority) was established pursuant to

Section 373.713 and 163.01 of the Florida Statutes to meet the regional water supply needs of its four

Member Governments: Charlotte, DeSoto, Manatee, and Sarasota counties. In addition, the Authority also

serves the City of North Port as a customer and maintains an emergency interconnect with the City of

Punta Gorda and the Englewood Water District. Throughout this document, the Authority’s four Member

Governments, customer, and entities with emergency connections will be collectively referred to as

“Customers”.

To fulfill its mission and vision, the Authority withdraws and stores surface water from the Peace River in

its reservoir system, which includes two aboveground reservoirs with a combined storage capacity of 6.52

billion gallons. Reservoir water is treated at the Peace River Facility (PRF), which is located in DeSoto

County and has a treatment capacity of 51 million gallons per day (mgd). Finished drinking water from

the PRF is delivered to Customers through approximately 70 miles of large diameter transmission mains.

Excess finished water may also be directed to the Aquifer Storage and Recovery (ASR) system during

wet periods to be subsequently withdrawn during dry periods for reservoir augmentation.

At the PRF, reservoir water is treated with powdered activated carbon (PAC) for taste and odor control,

followed by coagulation with aluminum sulfate, flocculation, sedimentation, primary disinfection with

chlorine followed by chloramines for secondary disinfection, filtration, and pH stabilization.

This document serves as the Authority’s Water Quality Master Plan (WQMP), which specifically focuses

on how treatment and transmission facilities are performing today with respect to current and potential

future regulatory requirements and Customer needs. The WQMP also identifies and prioritizes potential

opportunities to improve water quality. The WQMP objectives are:

• Identify existing and future water quality regulations that could impact the Authority and

its Customers;

• Assess the quality of finished water from the PRF and existing operations throughout the

Regional System to develop water quality and operational baselines;

• Provide guidance on implementation of strategies/methods for water quality

improvements;

• Assess the potential implications of establishing regional water quality standards for

delivered water.

The above objectives are discussed within six main sections of the WQMP, which include:

• Section 2, Regulatory Review and Outlook for Drinking Water Quality.

• Section 3, Current Conditions in the Peace River Manasota Regional Water Supply

System.

• Section 4, Treatment Evaluation for Additional TOC Removal at PRF.



Final Report


• Section 5, Corrosion Control Evaluation.

• Section 6, Regional Water Quality Standards Evaluation.

• Section 7, Conclusions and Next Steps.

Section 2 – Regulatory Review and Outlook for Drinking Water Quality

Section 2 includes a comprehensive review of current and future water quality regulations, summarizing

the pertinent regulations that may affect the Authority’s existing and future water supplies. Based on the

review of these regulations, the Authority complies will all existing water quality regulations. Several

potential future regulations that may impact the Authority are summarized in Table ES-1.

Table ES-1: Potential Future Regulations of Concern

Regulation/Constituent Regulatory Timing PRF Treatment Implications

UCMR 4 algal toxins

Near future (algal toxins are

subject to potential regulation

after UCMR 4 monitoring)

• Existing removal capabilities and any need for

enhancements would need to be verified through

sampling

Strontium Future (unknown)

• Existing removal capabilities and any need for

enhancements would need to be verified through

sampling

Perchlorate Anticipated June, 2020 • No existing treatment barriers for perchlorate at the PRF

Chlorate

Future (may be included in the

six-year review of the Stage 2

DBP Rule)

• No existing treatment barriers for chlorate at the PRF

cVOCs Previously anticipated May,

2019 (delayed)

• PRF provides VOC removal with powdered activated

carbon addition and coagulation/sedimentation/filtration.

Nitrosamines

Anticipated 2022 (if part of the

fourth six-year review of the

DBP regulations)

• Benchmarking recommended due to use of

chloramines; may require changes in distributed water

management

Manganese Future (unknown)

• Uncertain removal capacity at the PRF;

coagulation/sedimentation/filtration is likely to remove

manganese, but dependent on influent speciation

Chromium VI Future (unknown; current MCL

of 0.1 mg/L)

• Uncertain removal capacity at the PRF; removal via

adsorptive media and coagulation/

sedimentation/filtration are a function of pH and other

site specific conditions.

Contaminants of emerging

concern (CECs) Future

• Powdered activated carbon addition and

coagulation/sedimentation/filtration provide some

removal capacity.

Microbial constituents Future • Removal via disinfection

Per- and polyfluoroalkyl

substances (PFAS)

Near future (EPA released

action plan in 2019)

Existing USEPA health

advisory level of 70 ng/L for

combined PFOS and PFOA

Ongoing development of state-

specific MCLs

• Powdered activated carbon addition at the PRF may

provide removal of PFAS; however, the sufficiency of

this treatment barrier is based on source water

concentrations

Lead and Copper Rule

Revisions

2019 (delayed; released for

public comment in October

2019)

• May impact current corrosion control strategy (further

discussion in Section 5 on current strategy and future

implications due to LCR revisions)



Final Report


To prepare for these regulations, near term monitoring and sampling are recommended for the following

rules and parameters:

• Monitoring of regulatory developments:

o PFAS

o Lead and Copper Rule (LCR) revisions

• Water quality sampling:

o UCMR4 (Algal Toxins)

o Strontium

o Perchlorate

o Chlorate

o Nitrosamines

o Manganese

o PFAS

Based on the review of the existing and potential future finished water quality targets and the role of each

individual treatment barrier, the PRF is well equipped for the removal of multiple contaminants; however,

some additional barriers may be necessary in the future to meet potential new rules and Customer

expectations, as detailed in Section 2.

Section 3 – Current Conditions in the Peace River Manasota Regional Water Supply System

Section 3 includes a review of water quality data for raw, treated, and delivered water; Customer

complaint logs; and descriptions of operational protocols from the Authority and its Customers. These

data were used to characterize current conditions in the Regional System, which are referred to as the

water quality baseline. Historical data was organized and assessed using a business intelligence tool

called Microsoft Power BI.

The PRF’s performance relative to the regulatory water quality criteria was assessed using data from

2016, 2017, and 2018 quarterly compliance reports, which confirmed that the Authority is in compliance

with all Federal and State drinking water regulations.

Section 3 also assesses relationships between raw water quality and variability at the PRF, disinfectant

byproduct (DBP) formation and TOC, and disinfectant residual stability. These efforts help to identify

the impact of raw water quality on treatment, finished water quality, and distributed water quality, as well

as the role of the Authority’s raw water reservoir storage system on influent water quality to the PRF. The

reservoir system significantly reduces the magnitude of variability of the water quality being sent to the

PRF as compared to the variability seen in the Peace River, which benefits treatment and the consistency

of finished water quality. Finished water TOC concentrations at the PRF are fairly stable, generally

ranging from 2.5 to 4.5 mg/L, and DBP concentrations are consistently below associated regulatory limits

of 80 µg/L for trihalomethanes (THMs) and 60 µg/L for haloacetic acids (HAAs). Review of data related

to the disinfectant stability of finished water leaving the PRF shows that the observed TOC variability

does not have a substantial impact on chloramine residual in finished water and/or at the two points of

connection where measurements are taken, which suggests that the stability of the chloramine residual

leaving the PRF is fairly consistent over time.



Final Report


Additional water quality sampling was conducted as part of this WQMP to compliment the historical

water quality data. These additional data were collected to quantify the relationship between TOC, DBP

formation, and chloramine stability, as well as inform the extent to which TOC is amenable to additional

removal by various treatment processes, as further discussed in Section 4. The additional water quality

sampling assessed the following performance and water quality parameters:

• Disinfection byproduct formation potential tests (DBPFPs),

• Chloramine decay monitoring,

• TOC and ultraviolet absorbance at 254 nm (UV254),

• Fluorescence excitation-emission matrix (EEM) scans, and

• Bromide, barium, and silica analyses.

The DBPFP results were compared to PRF finished water TOC measurements. The results in Figure 3-8

demonstrate the importance of TOC removal; THM concentrations, and to a lesser extent HAA

concentrations, increase as a function of finished water TOC concentrations, which is consistent with the

observed historical data trends (Figure 3-5). The results shown in Figure 3-9 suggest that the stability of

the chloramine residual leaving the PRF is fairly consistent over time. It should also be noted that the

results shown in Figure 3-9 are intended to serve as an indicator of chloramine stability variability over

time, but not representative of the actual rate of decay in the distribution system because conditions in the

distribution system are different than the experimental conditions employed herein. TOC, UV254, and

SUVA254 were collected to inform the suitability of various treatment processes for the removal of

additional TOC at the PRF. Sampling results for these parameters show that natural organic matter in

Peace River are not only variable from a quantity standpoint (i.e., TOC concentrations), but also from a

quality standpoint thus indicating that seasonal factors (e.g., increased precipitation and temperatures) not

only increase the delivery of natural organic matter to the Peace River, but specifically natural organic

matter that may be characterized as aromatic.

The EEM (fluorescence regional integration or FRI) data show that raw and treated water fluorescence

are associated with fulvic- and humic-like (i.e., aromatic) organic compounds. FRI results for finished

water in Figure 3-12 suggest that if additional TOC removal is needed, the selected treatment process

should be one that targets humic- and fulvic-like compounds because they are the dominant components

in residual TOC.

Silica, bromide, and barium data shown were collected specifically to inform the extent to which certain

treatment enhancements may be appropriate for the PRF for increased TOC removal; these data are

discussed further in Section 4.

Section 3 also includes assessing the operational baseline with respect to two major operational areas:

source water withdrawal protocols practiced by the Authority and disinfection trimming protocols

practiced by Customers. In summary, the Authority diverts water from the Peace River to the reservoir

system in accordance with their water use permit (WUP) withdrawal schedule, as well as using daily

water quality monitoring of parameters such as total dissolved solids (TDS) and algae counts, to

maximize stored water availability while managing water quality. Historical water quality trends suggest

that additional water quality-based constraints on Peace River diversions to the reservoir system may

further improve influent water quality to the PRF, such as those that would minimize river withdrawals

when TOC is peaking. Additionally, the Authority benefits from an ASR system in which up to 6.3



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billion gallons of fully treated water from the PRF may be stored for later re-treatment and use.

Operational considerations could include increasing the use of this low TOC resource to blend during

periods of higher TOC in the river/surface water system to mitigate reservoir TOC.

Distributed water from the PRF is treated with sodium hypochlorite and ammonium hydroxide for

secondary disinfection using chloramines. Disinfection byproduct sampling results indicate the

Authority’s disinfection protocols achieve excellent results in minimizing DBP formation at the PRF

effluent and at the POCs with Customer’s distribution systems. The disinfectant residual may be

augmented by Customers after POC’s, depending on their preference and distribution system profile.

Table 3-11 identifies the Customer’s disinfection trimming approach. It is recommended that Authority

and Customer staffs continue active communications regarding disinfection practices and distribution

system boosting protocols.

Section 4 – Treatment Evaluation for Additional TOC Removal at PRF

Section 4 evaluates potential treatment options to further enhance the Authority’s finished water quality

as it relates to TOC. Reduced source water TOC concentrations can reduce chemical demands, and

improve clarification and filter performance; reduced finished water TOC can reduce the potential for

DBP formation, improve disinfectant residual stability, minimize nitrification potential in the distribution

system, reduce flushing requirements, and possibly allow for conversion to free chlorine within the

distribution system in the future.

A TOC treatment goal of 1.5 mg/L was used for the conceptual assessment of additional TOC removal.

Select treatment options considered as part of this study include:

• Post filtration GAC contactors

• Ozonation followed by biological activated carbon (O3-BAC) filtration

• Magnetic ion exchange (MIEX) pretreatment

Preliminary jar testing results suggested that MIEX treatment was not complementary to alum

coagulation for the PRF and did not improve overall TOC removal, therefore, this technology was not

further evaluated. For this desktop evaluation, the GAC and O3-BAC TOC removal efficiencies utilized

were 70% and 30%.

Conceptual designs of the above treatment options were based on annual average daily flow (AADF) for

the PRF for both existing and future capacities. It was also assumed that the Authority would implement

a brackish groundwater RO treatment plant that would partially reduce the TOC of the regional water

through blending with finished water from the PRF with the above treatment technologies in use. The

conceptual ASCE Class V cost estimate for the GAC and O3-BAC systems are presented in Table ES-2

and Table ES-3.



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Table ES-2: Conceptual GAC System Cost Estimate

Flow

Scenario

Overall

Plant

Capacity

(MGD)

GAC

Capacity

(MGD)

Estimated

Capital

Cost

($)

Estimated

O&M

Costs

($/yr)

Estimated

Total

Amortized

Cost

($/yr)

Estimated

Total

Present

Worth

Cost

($)

Estimated

Cost per

1,000 gallons

($/1,000 gal)

Current

Capacity 55 30 $ 22.6 M $ 1.3 M $ 3.0 M $40.5 M $ 0.28

Future

Capacity 77 45 $ 27.6 M $ 2.0 M $ 4.1 M $55.2 M $ 0.25

Table ES-3: Conceptual O3-BAC System Cost Estimate

Flow

Scenario

Overall

Plant

Capacity

(MGD)

O3-BAC

Capacity

(MGD)

Estimated

Capital

Cost

($)

Estimated

O&M

Costs

($/yr)

Estimated

Total

Amortized

Cost

($/yr)

Estimated

Total

Present

Worth

Cost

($)

Estimated

Cost per

1,000 gallons

($/1,000 gal)

Current

Capacity 55 30 $ 45.9 M $ 1.0 M $ 4.4 M $59.7 M $ 0.41

Future

Capacity 77 45 $ 63.3 M $ 1.6 M $ 6.2 M $85.4 M $ 0.38

While there are several potential benefits to operating the regional system at lower TOC concentrations,

previously discussed, a cost-benefit analysis was performed and was limited to consideration of savings

due to reduced flushing requirements.

Systemwide flushing totals 2,775 kgal/day on average, which is a significant amount of water loss and

operational impact. Assuming an average rate of $3 per thousand gallons, there is a total possible savings

of up to $8,300 per day or approximately $3M per year for the Customers if flushing was completely

eliminated. However, it is reasonable to assume some flushing would still be practiced even at reduced

TOC levels due to distribution system hydraulics, maintenance needs, and other factors. Therefore, the

savings could vary between 25% and 75% reduction of flushing or $0.75M to $2.3M annual savings.

Assuming 50% reduction of flushing (or approximately $1.5M in savings annually) by reducing the TOC,

estimated payback periods were calculated from the present worth of each TOC removal alternatives and

are shown below in Table ES-4.



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Table ES-4: Payback Periods for 50% and 75% Reduction of Flushing

Flow Scenario

GAC Ozone-BAC

50% Flushing Reduction

Payback Period (yrs)

75% Flushing

Reduction Payback

Period (yrs)





Existing Capacity 27 18 40 26

Future Flow 37 24 57 37

Based on this analysis, under current cost assumptions and assumptions pertaining to the value of water,

consideration of other benefits would be necessary to justify treatment enhancements for additional

removal of TOC at the PRF (e.g., reduced DBP production, taste and odor, CECs, etc.).

Section 5 – Corrosion Control Evaluation

Section 5 identifies the current practices and performance of the corrosion control strategy within each

Customer’s system and compares the continuation of the separate strategies across the region with a

combined regional corrosion control strategy. Corrosion control within the Authority’s regional system

currently consists of separate, unique approaches practiced by the Authority and its Customers. An

alternative corrosion control approach would be implementing a single corrosion control strategy

practiced by the Authority and each Customer. The primary drivers for this evaluation are the Lead and

Copper Rule (LCR) revisions and changing source water contributions to the regional system due to the

location and magnitude of future demands.

All Authority Customers have consistently met the lead and copper action levels of 0.015 mg/L and 1.3

mg/L, respectively, demonstrating the effectiveness of the current corrosion control practices. However,

even with the historical performance of the current corrosion control approach, there is the potential for

compatibility issues in the future due to changes in the blending of water sources and shifting of mixing

zones across the region. An alternative corrosion control approach is the implementation of a single

corrosion control strategy practiced by the Authority and each Customer. There are two generalized

options for a regional strategy, including:

• Alkalinity/pH/dissolved inorganic carbon adjustment to form insoluble scale compounds

which prevent the release of lead and copper,

• Corrosion inhibitor chemical addition, which generally requires target pH ranges for

optimization, so may include pH control chemicals

An overarching regional strategy would eliminate mixing zone concerns and address potential issues with

current corrosion control strategy compatibilities. However, the change in corrosion control strategy

would require desktop assessment and performance testing of the proposed strategy to comply with FDEP

requirements, capital costs for chemical feed and control improvements for the chosen regional corrosion

control approach, and increased regulatory monitoring.

It is recommended that the Authority and its Customers monitor the status of the proposed LCR

Revisions. It would be prudent to establish a regional dialogue focused on the final promulgated

provisions in the near future. A more appropriate time to consider changes in regional corrosion control



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strategies would be in conjunction with the rule revision implementation timetable and any associated

changes that may be required as a result of rule implementation.

Section 6 – Regional Water Quality Standards Evaluation

The Authority seeks to explore and understand alternative approaches used by other wholesale agencies

for the establishment and implementation of regional water quality standards. The value of this

assessment is to identify the potential for a more targeted approach for water quality requirements and

enhance documentation and communication related to water quality performance at POC’s with

Customers. Generally, regional water quality standards are agreed upon water quality requirements

between the wholesale supplier and their customers. The current approach used by the Authority and its

Customers is to meet State and Federal SDWA requirements at each POC. Two frameworks for the

implementation of additional requirements were considered, including action response plans and water

supply contracts (Table ES-5).

Table ES-5: Water Quality Standards Approach Comparison

Regional Water Quality

Standard Approach Detail


• Less prescriptive

• Low initial investment

• Creates communication avenues

• No compensation for water quality standards not met

• High personnel cost per event


• Guaranteed water quality

• Cost shared between members

• Likely to increase cost because of additional treatment

needed to meet guaranteed performance requirements

• Doesn’t facilitate communication

The initial recommendation for the Authority is to develop a hybrid action response plan, which increases

communication and troubleshooting to address water quality events, is more adaptable, and limits capital

costs. The final determination of a regional water quality standard approach will require further

discussion between the Authority and its Customers. To help inform the future discussions on a regional

water quality standard approach, it is recommended that the Authority begin water quality data collection

at the POCs as further described in Section 6.

Section 7 – Conclusions and Next Steps

The WQMP demonstrates the Authority’s commitment to providing consistent, high-quality drinking

water to its Customers, and the importance of water quality as a critical component of water supply

planning. The following are the main conclusions from the WQMP:

• Finished water produced at the PRF and delivered at POCs meets all existing required

State and Federal water quality regulations.

• Additional water quality monitoring will be beneficial in anticipation of future water

quality regulations. Specific water quality parameters of interest to the Authority may

include algal toxins, strontium, nitrosamines, manganese, CECs, PFAS, lead, and copper.



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• The reservoir system supports the Authority’s achievement of water quality-based goals

by dampening water quality variability observed in the river, thus enabling the delivery of

consistent influent water quality to the PRF, which benefits treatment and finished water

quality.

• The PRF achieves excellent removal of TOC, with coagulation, flocculation, and

sedimentation serving as the most substantial treatment barrier. At this time, there is no

immediate driver that requires additional TOC reductions; however, the Authority may be

motivated to further reduce TOC in finished water in response to regulatory changes

and/or operational considerations (e.g., to improve disinfectant residual stability; to

minimize flushing requirements; to reduce the risk of taste and odor events).

• The Authority and its Customers are meeting the current Lead and Copper Rule

requirements. The mixing zones between unique corrosion control strategies are expected

to increase under future conditions and should be actively monitored.

• A hybrid action response plan for regional water quality standards would be beneficial to

the Authority and its Customers.

Additionally, the following next steps are recommended for the Authority and its Customers to prepare

for potential regulatory, technological, and/or operational changes in the future:

• Implement additional water quality sampling to prepare for potential future water quality

regulations (Table 7-1: Sampling Recommendations to Prepare for Potential Future

Regulatory Changes).

• Explore the continued use of a business intelligence tool, such as Power BI, to assist with

data tracking and evaluation for the Authority and its Customers.

• Continue to monitor Long-term Revisions to the Lead and Copper Rule and associated

impacts. This includes performing additional water quality monitoring at POCs and at the

distribution system interfaces between Customers with dissimilar corrosion control

strategies and identifying if adjustments to the corrosion control processes are necessary.

• Monitor potential drivers for increased TOC removal and continue to explore TOC

removal options.

• Evaluate benefits of optimizing the schedule of withdrawals from the Peace River to

potentially reduce TOC loading to the reservoir system and the PRF. This may include

increased sampling from Peace River throughout the year to evaluate DBPFPs and

residual impacts. The results of these tests would enable the Authority to quantify the

extent to which TOC treatability and reactivity changes throughout the year and thus

whether TOC, in combination with flows and conductivity (or other water quality

parameters), should be used to determine preferred withdrawals. The implementation of

water-quality based withdrawals would require additional water quality monitoring and/or

the development of relationships between targeted water quality parameters and existing

monitors.

• Consider development of a water quality model to assist with optimization of river water

withdrawals to meet water supply and water quality objectives. The model may leverage

historical and real-time data being collected by the Authority, as well as data and

projections developed by other parties.



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• Evaluate potential for additional TOC removal by further optimizing the existing

treatment processes, thus leveraging existing assets before investing in enhancements.

This may include an operational assessment of the PRF to assess potential improvement

opportunities related to finished water quality, operational efficiency, and reservoir

management.

• Continue to explore the potential implementation of an action response plan by engaging

Customers to determine their perceptions of associated benefits and challenges, as well as

each Customer’s water quality limits of interest that are not already required by regulation.

• Integrate the WQMP into future water supply planning efforts.



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| Background 1-1

Section 1. Background

The Peace River Manasota Regional Water Supply Authority (Authority) was established pursuant to

Section 373.713 and 163.01 of the Florida Statutes to meet the regional water supply needs of its four

Member Governments: Charlotte, DeSoto, Manatee, and Sarasota counties. In addition, the Authority also

serves the City of North Port as a customer and maintains an emergency interconnect with the City of

Punta Gorda and the Englewood Water District (Figure 1-1). Throughout this document, the Authority’s

four Member Governments, customer, and entities with emergency connections will be collectively

referred to as “Customers”. The Authority partners with its wholesale Customers to provide drinking

water to a population of over 900,000 people, with its mission and vision as follows:

• Mission: To provide the region with a sufficient, high quality, safe drinking water supply

that is reliable, sustainable and protective of natural resources now and into the future.

• Vision: Through cooperation and collaboration, the Authority and its Customers shall

create, maintain and expand a sustainable, interconnected regional water supply system.

To fulfill its mission and vision, the Authority withdraws and stores surface water from the Peace River to

its reservoir system, which includes two aboveground reservoirs with a combined storage capacity of 6.5

billion gallons. Reservoir water is treated at the Peace River Facility (PRF), which is located in DeSoto

County and has a treatment capacity of 51 million gallons per day (mgd). Finished drinking water from

the PRF is delivered to Customers through approximately 70 miles of large diameter transmission mains.

Excess finished water may also be directed to the Aquifer Storage and Recovery (ASR) system during

wet periods to be subsequently withdrawn during dry periods for reservoir augmentation. The ASR

system has a design, usable storage capacity of 6.3 billion gallons, and the system has proven to be

capable of total storage volumes greatly in excess of this design capacity. Currently, the ASR system is

solely recharged with finished drinking water, but testing is ongoing to use raw water for ASR recharge

and storage in the future to provide greater operational flexibility and reduce treatment costs.

At the PRF, reservoir water is treated with powdered activated carbon (PAC) for taste and odor control,

followed by coagulation with aluminum sulfate, flocculation, sedimentation, primary disinfection with

chlorine followed by chloramines for secondary disinfection, filtration, and pH stabilization (Figure 1-2).

The Authority is required to meet Federal and State drinking water regulations at the PRF and at points of

connection; no other water quality standards have been established between the Authority and its

Customers regarding delivered water. As a result, the Authority uses the Florida Department of

Environmental Protection (FDEP) drinking water standard maximum contaminant levels (MCLs) as

finished water quality goals.



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| Background 1-2

Figure 1-1: Peace River Manasota Regional Water Supply Authority and Customer Distribution System



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| Background 1-3

Figure 1-2: Peace River Facility Process Flow Diagram



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| Background 1-4

1.1 Water Quality Master Plan Objectives and Organization

This document serves as the Peace River Manasota Regional Water Supply Authority’s (Authority) Water

Quality Master Plan (WQMP), which specifically focuses on how treatment and transmission facilities are

performing today with respect to current and potential future regulatory requirements and Customer

needs. The WQMP also identifies and prioritizes potential opportunities to improve water quality. The

WQMP objectives are:

• Identify existing and future regulations that could impact the Authority and its Customers;

• Assess the quality of finished water from the Peace River Facility (PRF) and existing

operations throughout the Regional System to develop water quality and operational

baselines, respectively;

• Provide guidance on implementation of strategies/methods for water quality

improvements;

• Assess the potential implications of establishing regional water quality standards for

delivered water.

The above objectives are discussed within six main sections of the WQMP, which include:

• Section 2, Regulatory Review and Outlook for Drinking Water Quality, provides a review

of existing and potential future drinking water quality regulations that may impact the

Authority’s water supplies. Additionally, the existing treatment barriers at the PRF are

evaluated with respect to existing and potential future water quality targets.

• Section 3, Current Conditions in the Peace River Manasota Regional Water Supply

System, is a summary of the historical data review that was conducted for the PRF and

regional distribution system to develop the water quality baseline and operational baseline.

A water quality dashboard is presented, and selected elements of the water quality

baseline are explored in detail, including raw water quality and variability, disinfection

byproduct (DBP) formation, disinfectant residual stability, and monitoring results for

unregulated contaminants. The operational baseline is characterized with respect to four

major areas: source water withdrawal protocols, disinfection, flushing, and corrosion

control.

• Section 4, Treatment Evaluation for Additional TOC Removal at PRF, discusses potential

drivers and strategies for reduced total organic carbon (TOC) concentrations in distributed

drinking water in the regional system. Reduced TOC concentrations have the potential to

reduce DBP formation, increase disinfectant stability, and minimize taste and odor

complaints. Preliminary strategies for TOC reductions include granular activated carbon,

ozone-biofiltration, and magnetic ion exchange treatment at the PRF, as well as a new

brackish water reverse osmosis facility. For each strategy, a description, cost estimate, and

discussion of advantages and disadvantages are presented.

• Section 5, Corrosion Control Evaluation, describes the current performance of the lead

and copper corrosion control strategies practiced by the Authority and Customers, and

explores the compatibility between the unique strategies practiced by neighboring



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| Background 1-5

Customers. An evaluation of a potential regional corrosion control strategy is also

presented.

• Section 6, Regional Water Quality Standards Evaluation, discusses examples of

wholesale water suppliers across the United States that use different approaches for the

establishment and implementation of regional water quality standards. Two frameworks

are considered: action response plans and water supply contracts.

• Section 7, Conclusions and Next Steps, summarizes the conclusions and recommends next

steps for the WQMP.



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| Regulatory Review and Outlook for Drinking Water Quality 2-1

Section 2. Regulatory Review and Outlook for Drinking Water Quality

The Safe Drinking Water Act (SDWA) was enacted in 1974 to regulate the nation’s public drinking water

supplies and protect public health. It was amended in 1986 and 1996 to improve protection of drinking

water quality as well as include detailed coverage for sources of drinking water: rivers, lakes, springs, and

groundwater. The current SDWA mandate includes source water protection, water treatment, finished

water distribution, and public information.

Under the SDWA, the United States Environmental Protection Agency (USEPA) is authorized to

establish enforceable standards for drinking water which include natural and man-made constituents and

minimal treatment requirements. These regulations establish health-based maximum contaminant levels

(MCLs) for specific drinking water constituents and identify the approved testing methods for each

contaminant. “Primacy” is the authority that allows a state to implement and enforce the SDWA within

the jurisdiction of that state. The USEPA can delegate primacy to a state if the state provides assurance

that it will adopt drinking water standards at least as stringent as the federal standards and can

appropriately enforce those standards. In Florida, the Florida Department of Environmental Protection

(FDEP) has primacy authority to enforce the SDWA. This section summarizes the pertinent regulations

that may affect the Authority’s existing and future water supplies.

2.1 Existing Federal Regulatory Requirements

Drinking water rules are designated as either primary or secondary standards. Primary standards target

public health issues and are enforceable; they apply to all public water systems. Constituents with primary

standards are classified as follows: microorganisms, disinfectants, disinfection by-products, radionuclides,

organic chemicals, or inorganic chemicals. Secondary standards are related to aesthetic qualities such as

color, taste, and odor and are not enforced by the federal government; however, states may choose to

adopt them as enforceable standards. The state of Florida enforces compliance with the secondary MCLs.

Under the authority of the SDWA, the USEPA has promulgated regulations that are applicable to public

water systems, including:

• Amendments to the SDWA (National Primary Drinking Water Regulations), 1986 and

1996

• Surface Water Treatment Rule (SWTR), 1989

• Total Coliform Rule (TCR), 1989

• Lead and Copper Rule (LCR), 1991

• Interim Enhanced Surface Water Treatment Rule (IESWTR), 1998

• Stage 1 Disinfectants and Disinfection By-Products Rule (Stage 1 D/DBPR), 1998

• Radionuclides Rule, 2000

• Arsenic Rule, 2001

• Filter Backwash Recycling Rule (FBRR), 2001

• Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR), 2002

• Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR), 2006

• Stage 2 Disinfectants and Disinfection By-Products Rule (Stage 2 D/DBPR), 2006



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• Groundwater Rule (GWR), 2006

• Revised Total Coliform Rule (RTCR), 2013

• America’s Water Infrastructure Act (AWIA), 2018

The progress of regulatory development is episodic. Initially in the 1970s and 1980s, activity under the

SDWA was rapid; more recently, the development and implementation of regulations has been more

methodical and frequently managed through negotiated rulemaking. Negotiated rulemaking involves

consultations between the USEPA and affected interest groups to develop the terms of a proposed

administrative rule prior to its publication in the Federal Register. Figure 2-1 illustrates the cumulative

nature of the regulation of drinking water constituents in the United States. The following sections

provide further details on the applicable rules to the Authority’s existing system.

Figure 2-1: Timeline for the Development of Drinking Water Rules in the United States

2.1.1 Surface Water Treatment Rules

The suite of Surface Water Treatment Rules (SWTR, IESWTR, LT1ESWTR, and LT2ESWTR) provides

a minimum level of treatment for drinking water production from surface water supplies. Surface water is

at a higher risk for contamination from runoff and other pollution sources. The treatment requirements for

surface water supplies are specific to protect against waterborne diseases caused by viruses and

microorganisms such as Giardia, Cryptosporidium, and Legionella. The initial SWTR required the



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disinfection of surface waters and the maintenance of a minimum residual disinfectant in the distribution

system, as well as a 3-log (99.9%) removal/inactivation of Giardia and 4-log (99.99%)

removal/inactivation of viruses. The SWTR also required combined filtered water turbidity monitoring

(less than or equal to 0.5 NTU) to demonstrate the adequacy of the filtration process.

The Interim Enhanced Surface Water Treatment Rule (IESWTR) was an incremental step to further

control of microbial pathogens, particularly Cryptosporidium, in systems that serve 10,000 persons or

more. It required these systems to calculate levels of microbial inactivation to understand the risk trade-

offs with disinfection byproducts (i.e., the microbial disinfection backstop). The Stage 1 D/DBPR was

published concurrent to the 1998 IESWTR which lowered the total trihalomethane (TTHM) MCL to

0.080 mg/L and added five haloacetic acids (HAA5), chlorite and bromate to the regulation. The Stage 1

D/DBPR also set Maximum Residual Disinfectant Levels (MRDL) for chlorine, chloramine, and chlorine

dioxide.

The IESWTR further limited individual and combined filter effluent turbidity standards and individual

filter turbidity provisions; it required a 2-log reduction in Cryptosporidium as well as individual and

combined filtered water turbidities be less than 0.3 NTU in 95% of samples and never exceed 1 NTU.

Finally, the IESWTR required covers on all new finished water storage facilities and sanitary surveys for

all surface water systems regardless of size.

The Long Term 1 ESWTR (LT1ESWTR) extended the provisions and protection of the IESWTR which

applied to systems larger than 10,000 persons to systems less than 10,000 persons.

The Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) further enhanced public

protection against illness caused by microbial pathogens, specifically targeting Cryptosporidium, and

assessed the microbial tradeoffs associated with the control of disinfection by-products (DBPs). The

LT2ESWTR rule implemented a risk-based approach to Cryptosporidium, requiring additional removal

based on source water protozoan monitoring. The rule included a “microbial toolbox,” which provided a

suite of treatment options that can be used to meet the rule required combination of inactivation and

removal.

As demonstrated by the presentation of historical data in Section 3, the Authority is in compliance with

the treatment requirements, monitoring and reporting for the suite of Surface Water Treatment Rules

(SWTR, IESWTR, LT1ESWTR, and LT2ESWTR).

2.1.2 Total Coliform Rule and the Revised Total Coliform Rule

The 1989 Total Coliform Rule (TCR) was substantially revised in 2014; the intent of both the original

rule and revisions was to ensure the microbial quality of water in the distribution system. Coliform

bacteria are used as indicator organisms that may signal the presence of contamination and overall

microbial quality. E. coli is a fecal coliform bacterium that is commonly found in the intestines of animals

and humans; the presence of E. coli in water is a strong indication of fecal pathogen contamination and

thus, the potential for disease burden. Each total coliform-positive routine sample must be tested for the

presence of E. coli and repeat samples are required. Repeat samples must be taken from sites specifically

related to the total coliform-positive routine samples.



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The 2014 revisions set a non-enforceable maximum contaminant level goal (MCLG) for total coliforms as

zero and an enforceable MCL of zero for E. coli. Any observation of E. coli in distribution system water

is an acute MCL violation that triggers a boil water order. The revised rule also established a performance

metric for total coliform observations; if 5% of the monthly samples taken in the distribution system are

total coliform positive, a system must conduct a Level 1 Assessment. A Level 1 Assessment is a detailed

review of system operational practices and may be conducted by the utility staff. The rule also established

a Level 2 Assessment that must be performed if the system has a second exceedance of the 5% total

coliform threshold in a rolling 12-month period, or if E. coli is detected in the distribution system. The

Level 2 Assessment is conducted by the state or a third party designated by the state. The Authority meets

the requirements of sampling and reporting for the Total Coliform Rule as required by the FDEP.

2.1.3 Disinfection Byproduct Rules

The 1979 TTHM Rule was the first endeavor by the USEPA to regulate a group of constituents. The 1979

TTHM Rule established the maximum allowable combined level of four disinfection byproducts

(chloroform, bromoform, dichlorobromomethane and dibromochloromethane) to 0.100 mg/L and was

based on an estimate of cumulative population exposure. The Stage 1 D/DBPR was published concurrent

to the1998 IESWTR; it lowered the TTHM MCL to 0.080 mg/L and added five haloacetic acids (HAA5),

chlorite and bromate to the regulation. It also set the Maximum Residual Disinfectant Levels (MRDL) for

chlorine, chloramines, and chlorine dioxide. The Stage 1 D/DBPR required systems using chlorine or

chloramines to monitor total organic carbon (TOC), alkalinity, TTHM, and HAA5, and demonstrate

adequate TOC removal based on source water quality. TOC was included in the D/DBPR because TOC

concentrations represent the overall presence of natural organic matter, which serves a precursor for

DBPs when subject to disinfection (e.g., chlorination, chloramination, ozonation).

The 2006 Stage 2 D/DBPR was promulgated in tandem with the Long Term 2 Enhanced Surface Water

Treatment Rule (LT2ESWTR) to further reduce the health risks associated with DBP formation in

drinking water. The second provision of the Stage 2 D/DBPR modified the method of calculating

compliance with the TTHM and HAA5 maximum levels. This change represented a shift from a total

population exposure estimate (i.e., a system-wide running annual average) to a locational running annual

average for TTHM and HAA5. Locational running annual average is the average concentration for

samples taken at a given sampling site during the previous four calendar quarters. The MCL values

remained equal to the Stage 1 D/DBPR levels of 0.080 mg/L and 0.060 mg/L for TTHM and HAA5, but

the locational running average is now used to determine compliance at each individual sampling location.

This approach intended to reduce exposure to high DBP concentrations in pockets of a distribution

system. Every monitoring site must comply with the locational running annual average for every DBP

group. The Authority is in compliance with the Disinfection By-Products Rules, reporting the data to

FDEP as required.

2.1.4 Lead and Copper Rule

In June 1991, the Lead and Copper Rule (LCR) was issued to protect public health by minimizing lead

and copper levels in drinking water. The rule specified a unique compliance approach, referred to as

action levels. The exceedance of an action level is not a regulatory violation, but rather signals the need to

re-evaluate the existing corrosion control strategy and adjust as needed. Remedial actions may include a



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new corrosion control treatment, source water monitoring, public education, and/or lead service line

replacement. The LCR was revised in October 2007 to clarify monitoring, treatment, customer awareness,

lead service line replacement, and compliance with public education requirements. Long-term revisions to

the LCR were scheduled to be released in 2017 but were delayed. The pre-proposal for the LT Revisions

was released in October 2019. The proposed long-term revisions include new trigger levels (in addition to

the current Action Levels), changes to the tap monitoring protocols, improved communication of results

to customers, new requirements for initiating corrosion control treatment, identification of lead service

lines in a utility by utility and state inventory, and lead service line replacement requirements. Previous

and ongoing revisions to the LCR are further discussed as potential future regulatory requirements

(Section 2.2.2.11). The Authority is in compliance with the current LCR requirements.

2.1.5 Radionuclides

In December 2000, the Radionuclides Rule was published as a revision of the original 1977 regulation.

The standards included a combined radium 226/228 of 5 picocuries (pCi)/L, a gross alpha standard for all

alpha emitters of 15 pCi/L, a combined standard of 4 millirems/year for beta emitters, and a new MCL of

30 µg/L for uranium. USEPA has considered regulating radon in drinking water, announcing its intention

to evaluate in 1999, but no additional advances have been made in more than a decade. The Authority is

in compliance with the radionuclide monitoring and reporting requirements.

2.1.6 Arsenic Rule

In January 2001, the Arsenic Rule was published which reduced the arsenic drinking water MCL from 50

µg/L to 10 µg/L. Additionally, the Arsenic Rule requires utilities to provide specific information in their

Consumer Confidence Report (CCR) depending on arsenic sampling results. If arsenic sampling results

are greater than the MCL of 10 µg/L, then a Health Effects Statement must be included in the CCR; if

arsenic sampling results are between 5 µg/L and 10 µg/L, then an Educational Statement must be

included in the CCR; no specific language is required in the CCR if arsenic sampling results are equal to

or less than 5 µg/L. Arsenic levels in Authority water are well below the regulatory requirements and

meet all state and federal requirements.

2.1.7 Filter Backwash Recycling Rule

The Filter Backwash Recycling Rule (FBRR) was published in June 2001 and requires recycled filter

backwash water, thickener supernatant, and liquids from dewatering processes to be recycled such that

they are subject a system’s existing conventional or direct filtration treatment train. Systems may recycle

at alternative locations only if approved by the State. The intent of the FBRR is to reduce the opportunity

for recycling practices to adversely affect the performance of drinking water treatment plants to help

prevent the presence of microbes in finished drinking water. Filter backwash, thickener supernatant and

liquids from dewatering processes at the PRF are returned to an approved location in accordance with the

Filter Backwash Recycling Rule.



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2.1.8 The Water Infrastructure Act of 2018

America’s Water Infrastructure Act (AWIA) of 2018 is a result of an October 2018 amendment to the

Safe Drinking Water Act. AWIA requires community water systems serving populations greater than

3,300 to prepare a Risk and Resilience Assessment (RRA) and Emergency Response Plan (ERP). The

RRA evaluates the risks to, and resilience of, the community water system, including risks from

malevolent acts and natural hazards, monitoring practices, and financial infrastructure. The ERP details

strategies and resources to improve resiliency, encompassing both physical and cyber assets. RRA

deadlines vary by the size of the population served. Development of the ERP must follow no more than

six months after the completion of the RRA (Figure 2-2).

Figure 2-2: RRA Deadlines for Systems Depending on the Size of the Population Served

AWIA does not specify the methodology to be used in developing the RRA and ERP; accordingly, many

utilities are relying on the use of the J100-10 American Water Works Association Risk and Resilience

Management Standard, which sets the requirements for all-hazards risk and resilience analysis and

management for the water sector and prescribes methods that can be used for addressing these

requirements. The Authority is currently preparing an RRA and will comply with the deadlines and

requirements of AWIA.

2.2 Potential Future Regulatory Requirements and Guidelines

2.2.1 Process for Identifying New Constituents to Regulate and/or Limit via Guidelines

Three criteria must be met for a compound to become regulated under the SDWA:

• The contaminant may, or is likely to, have an adverse effect on human health;

• The contaminant is known to occur in drinking water at a frequency and in high enough

concentrations to be a public health concern; and

• In the sole judgement of the USEPA Administrator, regulation of the contaminant presents

a meaningful opportunity for health risk reduction for persons served by public water

systems.



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This regulatory framework is slow and intentionally deliberate; the process allows the drinking water

community to gather enough data to understand occurrence, health effects and treatability. It also allows

for the development of cost-benefit analyses to determine the costs for achieving reduced health risks.

There are disadvantages to “slow and deliberate”; it can lead to public frustration, and a missed

opportunity to realize some portion of the public health benefit attributable to regulation.

The USEPA has several programs to identify compounds and microorganisms of concern that are not

currently subject to proposed or promulgated National Primary Drinking Water Rules (NPDWRs).

Currently, there are over 150,000,000 registered chemical substances in the Chemical Abstracts Service,

with millions added each year. Selecting target constituents for future regulation is a formidable

challenge.

The Drinking Water Contaminant Candidate List (CCL) and the Unregulated Contaminant Monitoring

Rule (UCMR) programs are the two primary tools that the USEPA uses to identify candidates for

regulation. Constituents that may be subject to near-term regulations or increasingly stringent limits

include perchlorate, chlorate, select volatile organic compounds (VOCs), chromium VI, nitrosamines, and

trace organic compounds such as algal toxins, personal care products and endocrine disruptors. Finally,

new drinking water regulations and/or guidelines can also be proposed through political action or non-

regulatory pathways (e.g., health advisory levels), which may lead to the accelerated adoption of drinking

water quality requirements.

2.2.1.1 Unregulated Contaminant Monitoring Rule (UCMR) and Contaminant Candidate List (CCL)

As a means for the USEPA to consistently inform the regulatory process about constituents not presently

regulated under the SDWA, the Unregulated Contaminant Monitoring Rule (UCMR) was promulgated

through the 1996 SDWA amendments. The CCL program identifies the universe of constituents that may

occur in public water systems which may be targeted for future regulatory action. The SDWA requires

that the CCL be updated every five years. For each cycle, the USEPA must decide whether to regulate at

least five of the constituents using a specific regulatory determination process which is summarized in

Figure 2-3.

The goal of the UCMR approach is threefold: it generates national occurrence data on five-year cycles for

up to 30 selected constituents per cycle, provides a platform for testing more recently developed sampling

methods and analytical procedures for constituents, and screens constituents using new or specialized

analytical methods. The constituents that have been investigated in each cycle of the UCMR are selected

from the CCL in the same cycle. The 1996 SDWA Amendments require that the USEPA review the data

collected under the UCMR program and announce whether they will or will not move forward to rule

making for at least five of the constituents; a positive determination means the constituent will move

forward into rule making while a negative determination indicates that no additional rule work will

proceed on the constituent at that time.

The UCMR CCL process has gone through three full cycles. The most recent regulatory determination

arose from CCL3, which was finalized on January 4, 2016 and identified strontium as a candidate for

future regulation development. CCL4 was finalized on November 17, 2016, after which the USEPA

published UCMR4 in December 2016. Monitoring under UCMR4 will take place from 2018 to 2020. The



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UCMR4 parameters are wide ranging and include pesticides, algal toxins, metals, unregulated haloacetic

acids, alcohols, and semi-volatiles. The compounds are divided into two groups: 10 cyanotoxins and 20

additional constituents. All surface water (SW) systems and groundwater under the direct influence of

surface water (GWUDI) systems serving more than 10,000 people are required to monitor all 30 UCMR4

constituents, which are listed in Table 2-1, Table 2-2, and Table 2-3.

Following the conclusion of the national sampling and reporting for UCMR4, the USEPA will proceed to

making regulatory determinations (both positive and negative) for at least five of the parameters on these

lists. A regulatory determination is the formal decision on whether the USEPA should initiate a process to

develop a national primary drinking water regulation for a specific contaminant.

In July 2019, the USEPA initiated UCMR5 discussions and potential approaches to developing the

proposal include extensive monitoring for per- and polyfluoroalkyl substances (PFAS) as well as other

compounds of interest; a proposed rule is expected by Summer 2020 with a final rule in Winter 2021.

Figure 2-3: Federal Safe Drinking Water Act Standard Setting Process



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Table 2-1: Cyanotoxins to be Sampled under UCMR4

Analyte CAS Registry Number EPA Method Number Minimum Reporting Level (µg/L)

total microcystins N/A 546 0.300

microcystin-LA 96180-79-9 544 0.008

microcystin-LF 154037-70-4 544 0.006

microcystin-LR 101043-37-2 544 0.020

microcystin-LY 123304-10-9 544 0.009

microcystin-RR 111755-37-4 544 0.006

microcystin-YR 101064-48-6 544 0.020

nodularin 118399-22-7 544 0.005

anatoxin-a 64285-06-9 545 0.030

cylindrospermopsin 143545-90-8 545 0.090

Table 2-2: HAAs, Bromide, and TOC Required to be Sampled under UCMR4

Analyte

CAS

Registry

Number

Analytical

Method

Minimum

Reporting

Level (µg/L)

Maximum

Contaminant Level

Goals* (µg/L)

HAA9

HAA5

dichloroacetic acid

(DCAA) 79-43-6 EPA 552.3 0.2 0

monochloroacetic acid

(MCAA) 79-11-8 EPA 552.3 2.0 70

trichloroacetic acid

(TCAA) 76-03-9 EPA 552.3 0.5 20

HAA6Br

monobromoacetic acid

(MBAA) 79-08-3 EPA 552.3 0.3 N/A

dibromoacetic acid

(DBAA) 631-64-1 EPA 552.3 0.3 N/A

bromochloroacetic acid

(BCAA) 5589-96-8 EPA 552.3 0.3 N/A

bromodichloroacetic acid

(BDCAA) 71133-14-7 EPA 552.3 0.5 N/A

chlorodibromoacetic acid

(CDBAA) 5278-95-5 EPA 552.3 0.3 N/A

tribromoacetic acid

(TBAA) 75-96-7 EPA 552.3 2.0 N/A

Total Organic Carbon (TOC) 7440-44-0 SM 5310C 0.3 mg/L N/A

Bromide 24959-67-9 EPA 300.0 5 N/A



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Table 2-3: Additional Constituents to be Sampled Under UCMR 4

Analyte CAS Registry Number EPA Method Number

Minimum Reporting Level

(µg/L)

Metals

germanium 7440-56-4 200.8 0.30

manganese 7439-96-5 200.8 0.40

Pesticides alpha-hexachlorocyclohexane 319-84-6 525.3 0.01

chlorpyrifos 2921-88-2 525.3 0.03

dimethipin 55290-64-7 525.3 0.20

ethoprop 13194-48-4 525.3 0.03

oxyfluorfen 42874-03-3 525.3 0.05

profenofos 41198-08-7 525.3 0.30

tebuconazole 107534-96-3 525.3 0.20

total permethrin (cis- & trans-) 52645-53-1 525.3 0.04

tribufos 78-48-8 525.3 0.07

Alcohols 1-butanol 71-36-3 541 2.00

2-propen-1-ol 107-18-6 541 0.50

2-methoxyethanol 109-86-4 541 0.40

Semi-volatile Organic Chemicals butylated hydroxyanisole 25013-16-5 530 0.03

o-toluidine 95-53-4 530 0.007

quinoline 91-22-5 530 0.02

2.2.1.2 Health Advisory Levels

The SDWA authorizes the USEPA to develop health advisory levels (HALs), which are health-based

guidance for unregulated drinking water constituents. Drinking water HALs are based on non-cancer

health effects for varying sub-populations (e.g., infants, children, elderly, and immunocompromised

persons). HALs allow the USEPA to quickly address potential threats to public health, especially if they

do not meet the three aforementioned criteria for regulation. HALs are non-enforceable; however, the

recommended drinking water concentrations in a HAL are likely to be interpreted by states and the public

as the equivalent of a regulation. Recommended drinking water concentrations in HALs are based solely

on the USEPA’s assessment of peer-reviewed science with the goal of providing the public with a margin

of protection from long-term exposure to drinking water constituents, taking the most sensitive sub-

populations into account. HALs do not undergo public review and comment prior to their release, nor are

they subject to cost-benefit analyses.

HALs are expected to be an increasingly important tool for the USEPA in the future. HALs, such as those

that were recently released with respect to per- and polyfluoroalkyl substances (Section 2.2.2.10), can

result in varying limits across states and general uncertainty regarding appropriate water quality targets.

Utilities should closely monitor state and federal issuances of HALs, as well as remain informed as to

how source water and finished water qualities compare with HALs.



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2.2.2 Potential Federal Regulatory Updates

2.2.2.1 Algal Toxins

A group of constituents that are likely to be regulated in the near future are cyanotoxins. Cyanobacteria,

also known as blue-green algae, produce cyanotoxins which are a concern for water utilities worldwide.

Cyanobacteria in water supplies cause numerous problems for water treatment plants but are most

notorious for the metabolites they produce, including taste and odor compounds and toxins. Taste and

odor compounds such as 2-methyl isoborneol (MIB) and geosmin are indirectly regulated through the

secondary standard for odor. The primary modes of toxicity for algal toxins fall into three categories: (1)

hepatotoxins that adversely affect the liver; (2) neurotoxins that affect the nervous system; and (3)

dermatoxins which cause skin and mucous irritations.

Algal toxins are not currently regulated by the USEPA; however, the agency issued HALs for two

cyanotoxins in June 2015. The health advisory level covered 10-day health advisories for microcystins

and cylindrospermopsin. The USEPA has the health advisories set at or below 0.3 µg/L for microcystins

and 0.7 µg/L for cylindrospermopsin in drinking water for children pre-school age and younger. For

school-age children through adults, the USEPA recommends less than 1.6 µg/L for microcystins and 3.0

µg/L for cylindrospermopsin (Table 2-4). These HAL limits for drinking water account for the increased

vulnerability of young children relative to the rest of the population because they consume more drinking

water relative to their body weight. Additionally, a 10-day HAL (i.e., short-term HAL) was developed

because it was the USEPA’s position that a short-term HAL is consistent with the available data and the

most likely exposure scenario for cyanotoxins. At the current time and into the foreseeable future, the

FDEP intends to follow the federal guidelines for cyanotoxins in drinking water.

Table 2-4: USEPA Health Advisory Levels for Cyanotoxins in Drinking Water

Microcystins

10-Day Health Advisory Level

Cylindrospermopsin

10-Day Health Advisory Level

Pre-school age children and younger

(under 6 years old 0.3 µg/L 0.7 µg/L

School-age children and older (6 years

and older) 1.6 µg/L 3.0 µg/L

Three algal toxins were included on the CCL3. The CCL4 expands investigation into the algal toxins and

includes 10 toxins including variants of microcystin. Due to the availability of improved analytical

methods, CCL4 includes individual measurements of six specific microcystins, nodularin, anatoxin-a, and

cylindrospermopsin. Following the conclusion of UCMR4 monitoring, it is highly likely that rulemaking

will ensue for a group of algal toxins. In the interim, states and local governments have issued their own

standards, advisories and warnings regarding algal toxins.

The PRF is capable of removing algal toxins with existing treatment barriers, specifically powdered

activated carbon addition and coagulation/sedimentation/filtration. To better characterize source water

algal toxins of interest, removal capacity, and treatment implications (e.g., residuals production), the

Authority should consider measuring UCMR4 algal toxins in source and finished water during algae



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events, in addition to the MIB and geosmin monitoring that is already conducted.1 If additional treatment

is determined to be needed for algal toxins, the following processes are considered effective for the

removal/oxidation of microcystins: ozone, ozone with hydrogen peroxide, ultrafiltration,

nanofiltration/reverse osmosis, powdered activated carbon, granular activated carbon, slow sand filtration,

bank filtration, chlorine, permanganate, and conventional treatment.

2.2.2.2 Strontium

The USEPA will likely regulate strontium levels in drinking water. Strontium was included on the CCL3

list and the earlier National Inorganics and Radionuclides Survey (NIRS). A health reference level of 1.5

mg/L was set for strontium as part of the CCL3 regulatory determination process. Strontium is released

into fresh water from geologic weathering associated with sedimentary rocks such as gypsum, anhydrite,

rock salt, limestone, and dolomite. Anthropomorphic sources of strontium include air contamination from

milling processes, coal burning, and land application of phosphate fertilizers. Emissions-related strontium

is eventually deposited on land and soil. Strontium can accumulate in plants and organisms through

uptake and bioaccumulation, thus entering the human food chain. The major heath effect associated with

the stable form of strontium is skeletal deformation in children. Although some isotopes of strontium are

radioactive, this potential regulation is focused on the stable form of the element because the radioactive

isotopes are covered under the existing radionuclides rule.

The Authority may consider periodic sampling for strontium in anticipation of future rulemaking as

phosphate mining impacts its watershed. The Authority’s use of powdered activated carbon may provide

some removal capacity at the PRF, as strontium may be removed by adsorptive media depending on pH

and the presence of competing ions.

2.2.2.3 Perchlorate and Chlorate

The USEPA intends to issue a perchlorate regulation by June 2020 and to that end, proposed rulemaking

in June 2019. The proposed rule set both a Maximum Contaminant Level (MCL) and a Maximum

Contaminant Level Goal (MCLG) of 56 parts per billion (ppb). The Agency also has asked for comment

on alternative options including: (1) an MCL and MCLG of 18 ppb; (2) an MCL and MCLG of 90 ppb; or

(3) do not regulate by withdrawing the 2011 positive determination to regulate. The proposal includes

perchlorate monitoring and reporting requirements for public water systems as well as a list of treatment

technologies targeting perchlorate.

Several states have already established a perchlorate MCL, including California (6 µg/L) and

Massachusetts (2 µg/L). Nevada has an action level of 18 µg/L. Florida has not implemented state level

MCLs for perchlorate or chlorate. The Authority may consider sampling periodically in order to

1 The Authority monitors for MIB and geosmin in the reservoir system on a weekly basis from approximately March 15th to November 1st, depending on temperature trends; MIB and geosmin are monitored on a monthly basis for the remainder of the year. The increased monitoring frequency from March to November is warranted by the fact that algae blooms are more likely to occur during this time period. MIB and geosmin data are used to inform the PAC dose at the PRF, thus allowing for proactive treatment modifications in response to source water quality before taste and odor issues reach finished water storage.



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understand potential impacts of any related rulemaking. Sources of perchlorate include munitions, rocket

fuel, industrial sites, and hypochlorite. Perchlorate interferes with the ability of the thyroid to produce

hormones needed for normal growth and development.

In addition to perchlorate, chlorate (ClO3-) is another constituent that occurs in drinking water facilities

that use bulk hypochlorite or onsite-generated hypochlorite. In hypochlorite solutions, chlorate may form

during manufacture, transport, or storage, and concentrations tend to increase at high temperatures and

over time. Chlorate was on the CCL3 list and the USEPA has announced a chlorate health reference level

of 210 µg/L. For comparison, the World Health Organization and Health Canada have proposed chlorate

criteria of 700 and 100 ug/L, respectively. Chlorate is likely to be regulated in the future and it may be

included in the six-year review of the Stage 2 DBP Rule, which would shorten the time to final

determination and regulation for chlorate in comparison to the traditional contaminant rulemaking

pathway.

The existing treatment barriers at the PRF do not provide removal capacity for perchlorate or chlorate.

The following processes may be considered for perchlorate and/or chlorate removal if needed: ion

exchange, biological treatment, tailored granular activated carbon, and membrane separation.

2.2.2.4 Volatile Organic Compounds

The USEPA decided in 2011 to increase the stringency at which volatile organic compounds (VOCs) are

regulated. Some VOCs have been found to cause liver, kidney, central nervous system damage in addition

to eye, nose, and throat irritation. Some VOCs are also suspected or known human carcinogens. There are

currently eight regulated VOCs. USEPA planned to regulate eight additional compounds and revise the

regulations for the currently regulated VOCs under the auspices of what the Agency has called the

Carcinogenic VOC Rule (cVOC). Trichloroethylene (TCE) and tetrachloroethylene (PCE) are currently

regulated and would likely be subject to more stringent regulations. The following eight VOCs were

proposed to be regulated as part of USEPA’s contaminant grouping strategy (in addition to the eight

VOCs that are currently regulated): aniline, benzyl chloride, 1,3-butadiene, 1,1-dichloroethane,

nitrobenzene, oxirane methyl, 1,2,3-trichloropropane, and urethane.

VOCs are typically associated with known industrial contamination sites that impact a utility’s source

water. The most common contamination occurs in groundwater. However, surface water supplies are

vulnerable and an understanding of potential industrial sites in the watershed will help drive decision

making regarding potential VOC presence in the source water. The anticipated date for a draft final cVOC

rule was May 2019, but has been delayed.

The existing treatment barriers at the PRF that can provide VOC removal are powdered activated carbon

addition and coagulation/sedimentation/filtration.

2.2.2.5 Nitrosamines and Emerging Disinfection Byproducts

Emerging DBPs consist of myriad compounds that are produced through the reactions between

disinfectants and natural organic matter. These byproducts include trihalomethanes, haloacetic acids,

chloral hydrate, bromochloroacetic acid and an entire category of unknown organic halogens. More than

700 organic halogens have been identified. Due to the uncertainty in their abundance, occurrence and



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toxicity, there is much debate regarding potential public health relevance. One primary concern is the

comparison of DBPs that are formed using chlorine disinfection with those that are formed using

chloramine disinfection. There is no evidence that chloraminated water poses any different cancer risk

than that of chlorinated water, yet speculation persists. The use of chloramines does reduce the overall

exposure to regulated DBPs relative to free chlorine.

The Safe Drinking Water Act requires that USEPA review drinking water regulations at least once every

six years and make appropriate revisions. The USEPA looked closely at nitrosamines in their review of

the microbial and DBP rules in the third six-year review cycle which concluded in January 2017. In

September 2018, the USEPA opened comment to initiate the fourth six-year review and will certainly

include nitrosamines and emerging DBPs in that analysis.

If the USEPA incorporates rule making for new DBPs as part of the fourth six-year review of the DBP

regulations, the approval and implementation process may be shorter in time than the more traditional

positive regulatory determination pathway and new rule development. Based on the expected rule

revisions and compliance cycles, regulatory compliance for nitrosamines could be required by 2022.

The popularity of chloramines for secondary disinfection purposes has also brought increased awareness

of nitrosamines in drinking water, in particular N-nitrosodimethylamine (NDMA). Nitrosamines are

DBPs that form from the oxidation of precursors in chlorinated and chloraminated waters. Nitrosamines

have been found to strongly correlate with chloramine use, the use of certain polymers (e.g.,

POLYDADMAC), and ion exchange resins (e.g., MIEX). Health effect research indicates that

nitrosamines are likely carcinogenic and may be linked to other diseases such as Alzheimer’s,

Parkinson’s, and Type 2 diabetes.

Nitrosamines are not yet regulated with a primary MCL; five nitrosamines were on the CCL3. USEPA is

considering a specific nitrosamine rule but it has not currently published a regulatory plan. California has

established a 10 nanogram per liter (ng/L) notification level and Massachusetts has established a

regulatory limit of 10 ng/L for drinking water. The USEPA’s regulatory limit may be as low as 10 ng/L

with an MCL goal (MCLG) of zero because nitrosamines are considered likely carcinogenic compounds.

It is recommended that the Authority measure nitrosamines in finished and distributed drinking water to

establish a benchmark due to the use of chloramines and strong public/regulatory interest in the potential

health implications. The distributed drinking water sample locations that the Authority uses for DBP

monitoring would also be appropriate for nitrosamine analyses.

2.2.2.6 Manganese

Manganese is a naturally occurring element found in air, soil, and water. Manganese currently has a

secondary standard of 0.05 mg/L, due to its causing of colored water, staining, and metallic taste at

concentrations that exceed this threshold.

In addition to these aesthetic concerns, exposure to high concentrations of manganese may result in

various health effects depending on the route and duration of exposure. At this time, the potential federal

regulatory horizon for manganese is uncertain. Two states, Massachusetts and Minnesota, requested that

manganese be included on the CCL4. Manganese was on the CCL3 and at its conclusion, it was deemed

unnecessary to regulate it in drinking water. Recent toxicity studies suggest that ingestion of manganese



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may be related to neurological effects in children and are the new drivers for manganese inclusion in the

final version of CCL4. Canada recently set a new guideline for manganese in drinking water of 0.12

mg/L. More than 10 percent of the groundwaters in the US have manganese levels higher than the current

health advisory level (0.05 mg/L), which increases the likelihood that some regulation will be developed.

The Authority should consider seasonal monitoring of both raw sources and finished water for manganese

to prepare for potential changes in the status of manganese regulations. The existing treatment barrier at

the PRF that provides some removal capacity for manganese is coagulation/sedimentation/filtration;

however, the fate of manganese at the PRF is dependent on its influent character (i.e., dissolved, colloidal,

particulate).

2.2.2.7 Chromium VI

Studies and publications of the Environmental Working Group have renewed interest in chromium VI.

Chromium VI, previously thought to be only a contact hazard causing allergic dermatitis at high

concentration, has recently been implicated in cancer occurrence. Chromium is a naturally occurring

metal in rocks, plants, humans, soil and volcanic dust, and animals. It is mostly present as chromium III,

chromium VI, and the metal form of chromium, the latter two of which are produced in industrial

processes. Major sources of chromium include steel and pulp mills and natural deposit erosion.

Currently the USEPA regulates the total concentration of chromium in drinking water with an MCL of

0.1 mg/L. California regulates the total chromium concentration at 0.050 mg/L. Effective July 1, 2014,

California instituted a Chromium VI MCL of 0.010 mg/L, which was later rescinded on September 11,

2017 due to a judgment that the economic feasibility of the MCL was not properly considered. The

California State Water Resources Control Board is court-ordered to set a new MCL for Chromium VI. In

the meantime, the total chromium MCL of 0.050 mg/L is in effect.

If chromium VI is detected in the Authority’s source water, the existing treatment barriers at the PRF may

or may not provide for chromium VI removal, as removal via adsorptive media and

coagulation/sedimentation/filtration are a function of pH and other site specific conditions.

2.2.2.8 Trace Organic Compounds

A contaminant group that may be regulated in the future is trace organic compounds, also referred to as

contaminants of emerging concern (CECs) and micropollutants. These constituents include

pharmacologically active compounds, personal care products, endocrine-disrupting compounds, and other

organic compounds. Sources of endocrine-disrupting compounds as well as other trace organic

compounds include domestic waste, agricultural runoff, industrial sources, and solid waste. There are

currently no federal or state regulations that specifically address trace organic compounds. The UCMR3

included seven steroid hormones that may be characterized as endocrine disrupting compounds. Based on

the low frequency of occurrence, as well as the low levels observed, it is unlikely that the USEPA will

regulate these trace organic compounds, especially those that are readily oxidized by free chlorine.

It is recommended that the Authority monitor USEPA activity related to CECs and be aware of potential

changes to the regulatory status of this class of contaminants. If needed, powdered activated carbon

addition and coagulation/sedimentation/filtration provide some removal capacity for CECs.



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2.2.2.9 Microbial Constituents

Microbial constituents, including bacteria, viruses, and protozoa, associated with drinking water may

cause acute illness. Microorganisms, such as Cryptosporidium and Giardia lamblia, cause gastrointestinal

illness, or in the case of Legionella, cause a type of pneumonia, Legionnaire’s Disease. Enteroviruses and

noroviruses were on the UCMR3 due to concern regarding their presence in groundwater supply systems.

No microbial pathogens are included in the UCMR4. Pathogens in biofilms, such as Legionella and

Naegleria fowleri, are also microbial constituents of concern as they can thrive in building plumbing

systems, such as hospitals, hotels, schools, homes, and factories. It is not expected that new regulations

for specific microbes will be promulgated in the near term.

2.2.2.10 Per- and Polyfluoroalkyl Substances

Perfluorooctanesulfonic acid (PFOS) and perfluoroactanoic acid (PFOA) are two chemicals in a broad

group of chemicals referred to as per- and polyfluoroalkyl substances (PFAS). PFAS are persistent and

ubiquitous in the environment due to their use in commercial household products (e.g., stain- and water-

repellent fabrics, nonstick products, cleaning products), fire-fighting foams, food packaging, and other

production facilities and industries.

In May 2016, the USEPA established HALs for PFOS and PFOA based on the Agency’s assessment of

the latest peer-reviewed science and in consideration of the most sensitive populations. The lifetime

exposure HAL for combined concentrations of PFOS and PFOA in drinking water is 70 ng/L. This HAL

is substantially lower than the previously developed provisional advisory levels, which were 0.2 µg/L for

PFOS or PFOA individually in drinking water and 0.4 µg/L for the combined concentration.

The perfluoroalkyl substance HAL is based on peer-reviewed studies of the effects of PFOA and PFOS

on rates and mice, as well as epidemiological studies of human exposure to PFOA and PFOS. The HAL

was developed in response to evidence of adverse health impacts related to PFOS and PFOA

consumption, including developmental effects to fetuses during pregnancy and breastfed infants, cancer,

liver damage, immune effects, thyroid problems, and other effects. The combined PFOS and PFOA

lifetime exposure HAL was calculated to offer a margin of protection for fetuses during pregnancy and

breastfed infants, as these are the most sensitive populations.

As previously discussed, HALs are non-enforceable at the federal level and are very likely to result in the

establishment of varying drinking water limits at the state level. Table 2-5 provides a summary of PFAS

drinking water regulations and guidelines that have been developed by states since the release of the

USEPA’s PFOS/PFOA HAL. In February 2019, the USEPA issued a PFAS Action Plan, which signaled

the USEPA’s intent to regulate PFOS and PFOA in drinking water, as well as expand toxicity

information, develop new PFAS characterization tools, develop remediation guidance, and leverage legal

tools to prevent future PFAS releases to the environment.

It is recommended that the Authority monitor USEPA and state activity related to PFAS and be aware of

potential changes in the regulatory status of this class of contaminants, as well as benchmark

concentrations in source and finished waters. Powdered activated carbon addition at the PRF may provide

some removal of PFAS at the PRF; however, granular activated carbon and ion exchange are the most

relied upon strategies for PFAS removal from drinking water.



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Table 2-5: Summary of State PFAS Regulations

State Regulations and/or Guidelines

Alaska Combined 70 ppt PFOA + PFOS HA (long term exposure)

Alabama Combined 70 ppt PFOA + PFOS HA (long term exposure)

Arizona Combined 70 ppt PFOA + PFOS

California 14ppt PFOA, 13ppt PFOS Notification Limit

Colorado Combined 70 ppt PFOA + PFOS (HA and GWQ standard)

Connecticut 70 ppt total Alert Level (PFOS, PFOA, PFNA, PFHxS, PFHpA)

Delaware Combined 70 ppt PFOA + PFOS HA (PFBS GW standard)

Iowa Combined 70 ppt PFOA + PFOS (GW standard)

Maine Combined 70 ppt PFOA and PFOS

Massachusetts 70 ppt total Guidance Values (PFOS, PFOA, PFHxS, PFNA and PFHpA)

Michigan Combined 70 ppt PFOA and PFOS, 11ppt PFOS in Surface Water

Minnesota 35 ppt PFOA, 27 ppt PFOS Health Based Levels (+ PFBA, PFBS, PFHxS*)

Montana Health Advisory for PFOA (41 ppt), PFOS (41 ppt), PFOA + PFOS < 70ppt

New Hampshire Proposed MCL for PFOA (38), PFOS (70), PFOA + PFOS <70, PFNA (23) and PFHxS

(85)

New Jersey 14 ppt PFOA (MCL), 13 ppt PFOS (MCL), 13 ppt PFNA (MCL)

New York MCL expected soon (10 ppt PFAS, 10 ppt PFOA)

North Carolina 140 ppt GenX

Pennsylvania Combined 70 ppt PFOA + PFOS HA (MCL under review*)

Rhode Island Combined 70 ppt PFOA + PFOS HA

Vermont Proposed Preventative Action Limit - 20 ppt total for 5 PFAS (PFOA, PFOS, PFHxS,

PFHpA, and PFNA)

West Virginia Combined 70 ppt PFOA + PFOS HA

2.2.2.11 Long-term Lead and Copper Rule Revisions

After being promulgated in 1991, the Lead and Copper Rule (LCR) went through a series of technical

amendments and more extensive revisions in January 2000 and October 2007 (Figure 2-4:). The intent of

the January 2000 revisions was to streamline requirements and promote consistent implementation of

effective corrosion control throughout the nation. The goal of the 2007 Short Term Revisions was to

enhance the implementation of the LCR in five main categories: treatment, monitoring, consumer



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awareness, public education, and lead service line (LSL) replacement. Since the promulgation of the 2007

Short Term Revisions, the USEPA has identified additional issues and concerns regarding the LCR.

Collectively, this effort is referred to as the USEPA Long Term Revisions and will serve to improve the

effectiveness of corrosion control, thus reducing exposure to lead and copper. The USEPA assembled a

working group to assist the National Drinking Water Advisory Council (NDWAC). This NDWAC

Working Group was asked to:

• Propose ways to reduce the complexity of the rule;

• Identify the level of discretion that should be allowed with respect to optimal corrosion

control treatment practices;

• Identify best practices for compliance sampling;

• Focus on key areas of concern, such as schools and childcare facilities and recommend

options.

Figure 2-4: Timeline of Lead and Copper Rule Amendments and Revisions

The USEPA identified the following items for development in the Lead and Copper Rule Long Term

Revisions:

• Lead service line (LSL) replacement;

• Improve optimal corrosion control treatment requirements;

• Incorporation of health-based benchmarks;

• Use of point of use (POU) filters;

• Clarify sampling requirements;

• Increase transparency and information sharing with the public; and

• Develop more specific public education requirements.

The LCR, in its existing and future forms, is a composite of multiple requirements that apply to systems

differently depending on system size and water quality. One important factor in considering potential

changes to the LCR is cost. In January 2018, the USEPA Office of Ground Water and Drinking Water



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provided examples of potential cost implications at a Federalism Consultation Meeting. Table 2-6 shows

the USEPA’s estimated financial impacts of widespread orthophosphate implementation as a corrosion

control strategy.

Table 2-6: Estimated Costs for Centralized Orthophosphate Treatment Systems

Public Water

System Size

(People Served)

Total System

Capital Cost

($)

Annual System

O&M

($)

Total Capital

Cost per

Household

($)

Annual O&M

Cost per

Household

($)

25 – 100 18,000 2,000 740 78

100 – 500 19,000 2,000 170 21

500 – 1,000 21,000 3,000 72 12

1,000 – 3,300 22,000 6,000 31 8

3,300 – 10,000 39,000 8,000 17 3

10,000 – 50,000 48,000 25,000 5 3

50,000 – 100,000 63,000 81,000 2 3

100,000 – 500,000 92,000 265,000 1 2

Long-term revisions to the LCR were scheduled to be released in 2017 but were delayed until October

2019 when the pre-publication proposed revisions were released for public comment. The proposed LCR

Revisions focus on the following key areas:

• A proposed “Trigger Level” distinct from the Action Levels,

• Lead and Copper Tap Monitoring,

• Corrosion Control Treatment,

• Service Line Inventory, and

• Lead Service Line Replacement.

The original LCR included a Lead Action Level of 15 ppb and 90th percentile levels above the Action

Level, which required specific response actions intended to reduce lead exposure. Under the 1991 rule,

treatment alternatives listed in the LCR included pH adjustment, adjustment of calcium carbonate

saturation, and the addition of orthophosphate or silicate inhibitors. Of these, the adjustment of pH and

the addition of orthophosphate have proven the most successful. The newly proposed revisions would

remove calcium hardness as an option for OCCT and specifies that any phosphate inhibitor must be

orthophosphate. The new proposed Trigger levels will differ from the original Action Levels because

systems with a 90th percentile Pb level above the Trigger Level of 10 ppb would be required to take

additional action including increased tap monitoring frequency, re-evaluate and optimize corrosion

control treatment, and perform lead service line replacement if the corrosion control treatment is not

effective. Systems not triggered to act in the past by the 15 ppb Action Level may be prompted to

evaluate corrosion control treatment under the 2019 proposed revisions if they exceed the new 10 ppb

Trigger Level.



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The proposed 2019 LCR Revisions introduce a new “Find-and-Fix” approach. At any individual sampling

site with a Pb concentration above 15 ppb, the system will be required to conduct follow-up lead testing

and local water quality parameter (WQP) monitoring. The system must submit a recommended solution

to decrease lead levels to the State within 6 months. Utilities will need to adopt new protocols for

evaluating and mitigating lead release on a site-specific basis.

The LCR revisions re-define sample site tier requirements and focus on sampling at sites with lead service

lines. Water systems will need to re-evaluate their sample site selection to determine if the current

compliance monitoring locations comply with the proposed requirements. Systems will also be required

to sample in schools and childcare facilities where high risk populations for lead health effects are

present. Utilities will need to develop a new sampling plan for these locations and develop procedures to

communicate the results.

Water systems will be required to evaluate specific orthophosphate doses of 1 mg/L and 3 mg/L as PO4 in

corrosion control studies required under the Rule. This requirement may increase orthophosphate usage in

systems that exceed the Trigger Level or Action Level. Calcium hardness addition to create a slightly

positive LSI would no longer be an acceptable corrosion control treatment strategy. However, if the

native water hardness allows the achievement of a positive LSI through pH adjustment alone (i.e., without

additional calcium carbonate addition) then that approach is expected to still be valid.

Systems with unknown or lead service lines will be required to track public and private service line

materials, which is a new paradigm for many water systems. Systems will have three years after the Rule

takes effect to submit a service line inventory and will be required to submit annual notification letters to

all customers with lead service lines or service lines of unknown material, noting that the public LSL will

be replaced if the customer replaces the private LSL. The service line inventory must be publicly

available, and for systems with a population greater than 100,000, the inventory must be electronic.

Systems will be required to update the service line inventory in the course of normal operations as service

lines are identified and may perform targeted identification to confirm service line materials. Systems

with unknown or lead service lines will be required to develop a Lead Service Line Replacement (LSLR)

Plan meeting specific requirements in the Revisions and define a replacement rate goal. Systems

exceeding the Trigger Level or Action Level at the 90th percentile will be required to replace LSLs

system-wide.

It is recommended that the Authority and its customers monitor the progress of the proposed LCR

revisions as discussed further in Section 5 and establish regional plans and dialogues to move forward in

the event that these revisions are adopted. Identifying opportunities for collaboration will benefit the

region.

2.2.2.12 Potable Reuse Regulations

While potable reuse is gaining viability as a potential source of water supply in Florida, there is still a

need for a regulatory framework to permit new facilities that would treat and deliver the supply. Table 2-7

summarizes the existing regulations related to water reuse, aquifer recharge and indirect potable reuse in

Florida. For direct potable reuse to be implemented successfully, state requirements for pilot testing,

monitoring, reporting, and operator licensing will need to be established.



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Table 2-7: Florida Administrative Code Chapter 62 Regulatory Summary

Section Title Description

520 Groundwater Classes, Standards, and Exemptions

Classifies groundwater and dictates the dimensions of zones of discharge for each class of groundwater. Provides regulatory information on water quality criteria exemption for discharges to groundwater.

524 New Potable Water Well Permitting in Delineated Areas

Regulates well construction, water quality testing, permit requirements, and inspections for areas within which ground water contamination is known to exist or which encompasses vulnerable areas or areas where a subsidy for restoration or replacement of contaminated drinking water supplies is provided.

528 Underground Injection Control

This includes all injection wells defined in subsection 62-528.300(1), F.A.C., as Class I, III, IV or V wells. Class II wells are regulated by the Florida Geological Survey under Chapter 377, F.S., and Chapters 62C-26 through 62C-30, F.A.C

610

Reuse of Reclaimed Water

and Land Application

Provides design and Operations and Maintenance criteria for land application systems that may discharge to Class G-I, G-II, and F-I ground waters, and requirements for Ground Water Recharge and Indirect Potable Reuse.

The State has developed a framework for potable reuse implementation which was puclished in December

2019. FDEP and the Water Management Districts actively promoted and funded this initiative through the

creation of the Potable Reuse Commission (PRC). The PRC is a consensus panel of eleven water

resource, industry, agricultural and health professionals, the objective of which is to develop a framework

for potable reuse implementation in Florida. The framework is intended to advise elected officials and

regulatory agencies on legislation, rule development and incentives. The commission worked with the

Water Research Foundation and the WateReuse Association to produce the framework guidance

document for the 2020 legislative session, along with fact sheets and public education materials that can

be used by stakeholders statewide.

The PRC released the final document to the public in December; the recommendations are available on

their website and include the reorganization of the current state indirect potable reuse regulations and that

new direct potable reuse regulations be included under Chapter 62 governing drinking water regulation.

The PRC is also recommended the use of “Appropriate Treatment Technology” to address pathogens and

emerging constituents in reclaimed water in contrast to requiring the use of a specific treatment process or

treatment trains. Appropriate Treatment Technologies would include proven water treatment processes

that achieve a treatment objective, protect public health, and protect the environment. Additional

recommendations pertain to the role of water use permits in potable reuse, the compatibility between

indirect potable reuse and environmental protection, and coordination between permitting agencies. Te

PRC has identified the following as recommended next steps: implement regulatory recommendations

through Technical Advisory Committees; incentivize and protect public investments in potable reuse; and

continue public education and outreach.

The Authority should continue to monitor regulatory changes associated with potable reuse as it evaluates

future water supply options.



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2.3 PRF Hazard Analysis and Critical Control Point (HACCP) Evaluation

The PRF is operated and monitored such that finished water meets a wide range of water quality targets,

including regulatory and non-regulatory limits. To characterize the PRF’s ability to meet finished water

quality targets and identify the role of each individual treatment barrier, a summary of the Authority’s

existing and potential future finished water quality targets was developed, as informed by Section Section

2, and the anticipated treatment efficacies of existing treatment barriers at the PRF were described. The

resulting matrix (Appendix A) informs the selection of suitable performance monitors at the PRF and

enables identification of areas with potential risk. The approach for developing the finished water quality

targets summary is described in Section 2.3.1 and the methods for describing treatment barrier efficacies

is described in Section 2.3.2.

2.3.1 Finished Water Quality Targets

The list of finished water quality targets provided in Appendix A spans existing regulations, existing

guidelines, and considerations for the future (Table 2-8). Existing regulations are those limits that the

Authority is obligated to meet by law, including Florida Department of Environmental Protection (FDEP)

primary and secondary MCLs. Existing guidelines include federal and state Health Advisory Levels

(HALs) from USEPA and Florida Department of Health (FDOH), respectively, as the Authority may aim

to achieve these unenforceable limits due to public health concerns, public interest, and/or potential future

regulatory developments. HALs are based solely on peer-reviewed science with the goal to provide the

public with a margin of protection from a lifetime exposure to drinking water constituents taking the most

sensitive populations into account. For future considerations, the Drinking Water CCL and UCMR were

used to select constituents that may be on the regulatory horizon, as these programs are the two primary

tools that the USEPA uses to identify candidates for regulation. Additionally, California State Water

Resources Control Board Drinking Water Notification Levels are included in the summary because,

although these notification levels and associated responses do not apply to utilities in Florida, regulatory

action in California tends to precede public interest and regulatory action across the United States.



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Table 2-8: Sources of Finished Water Quality Targets in the Authority HACCP Matrix

Category Source Description

Existing Regulations

FDEP Primary Maximum Contaminant Levels

FDEP has been granted authority by USEPA to implement the federal Safe Drinking Water Act. Florida has adopted USEPA regulations and rules to implement this program. These regulations set legal limits for contaminants in drinking water and testing schedules and methods that water systems must follow. Currently, approximately 90 contaminants are regulated under National Primary Drinking Water Regulations, which include enforceable, contaminant-specific standards called MCLs. These standards are established to protect public health and are calculated so that little or no adverse health risk would be expected based on a lifetime average consumption rate of two liters of water per day for 70 years (FAC 62-550.310).

FDEP Secondary Maximum Contaminant Levels

In addition to primary MCLs, USEPA also established National Secondary Drinking Water Regulations as part of the federal Safe Drinking Water Act. These secondary standards were established to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, odor, and color. In some states, compliance with secondary MCLs is non-mandatory; however, public water systems in Florida must monitor and report parameters with secondary MCLs and they are enforced by FDEP. Furthermore, although sodium is a federal secondary MCL, it has a primary MCL in Florida (FAC 62-550.320).

Existing Guidelines

USEPA Health Advisory Levels

Health Advisory Levels (HALs) serve as the informal technical guidance for unregulated drinking water contaminants to assist Federal, State, and local officials, and managers of public or community water systems in protecting public health as needed. They are not to be construed as legally enforceable Federal standards. Listed in Appendix A are USEPA Lifetime Health Advisory values, i.e., the concentration in drinking water that is not expected to cause any adverse noncarcinogenic effects for a lifetime of exposure, unless otherwise noted.

FDOH Health Advisory Levels

FDOH may also develop Health Advisories based on available technical information. FDOH develops HALs when a chemical is found in drinking water and no regulatory standard exists for the chemical. The HAL is a concentration of a chemical in drinking water that, based on available data, is virtually certain not to cause adverse human health effects if consumed over a lifetime. HALs provide guidance on the potential for these chemicals to cause harm to humans.

Future Considerations

California State Water Resources Control Board Drinking Water Notification Levels

Notification levels have been established in California as needed since the early 1980s. These are used to provide information to public water systems and others about non-regulated chemicals in drinking water that lack MCLs. When chemicals exceed notification levels, certain requirements and recommendations apply.

USEPA Contaminant Candidate List 4

The drinking water CCL is a list of contaminants that are currently not subject to any proposed or promulgated drinking water regulations but are known or anticipated to occur in public water systems. USEPA must consider health effects and occurrence information to place contaminants on the CCL. USEPA must place those contaminants on the list that present the greatest public health concern related to exposure from drinking water. USEPA uses the CCL to identify priority contaminants for regulatory decision making and information collection. The most recent CCL is CCL4.

USEPA Unregulated Contaminant Monitoring Rule 4

The 1996 Safe Drinking Water Act amendments require that once every five years, USEPA issue a new list of no more than 30 unregulated contaminants to be monitored by public water systems. This monitoring provides a basis for future regulatory actions, including occurrence and concentrations.



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The constituents in Appendix A are separated into six hazard categories:

• Microorganisms, e.g., adenovirus, Cryptosporidium,

• Inorganic chemicals, e.g., fluoride, mercury,

• Radionuclides, e.g., alpha particles, uranium,

• Organic chemicals, e.g., benzene, 1,4-dioxane,

• Disinfectants and disinfection byproducts, e.g., chlorine, bromate, NDMA, and

• Bulk water quality parameters, e.g., TOC, odor.

For each constituent, the following information is provided:

• Water quality target value and associated units,

• Source of the water quality target, e.g., FDEP primary MCL,

• Hazard description, e.g., potential carcinogen,

• Hazard source, e.g., herbicide in commercial agriculture, and

• Anticipated treatment efficacy of existing barriers at the Peace River Facility.

2.3.2 Treatment Efficacies

Appendix A shows existing treatment barriers at the PRF in terms of their anticipated removal capabilities

for individual contaminants. The identification of treatment barriers at the PRF and the description of the

removal performances for individual contaminants are critical for determining areas of potential risk for

finished water quality. The process flow diagram for the PRF is provided in Figure 1-2:, which includes

five treatment barriers: caustic addition, powdered activated carbon contact, coagulation, sedimentation,

filtration, free chlorination, and chloramination. Using the USEPA Drinking Water Treatability Database

and other references from published literature, these treatment barriers were described in terms of

anticipated removal efficiencies for listed contaminants using symbols shown in Table 2-9.

Table 2-9: Anticipated Removal Efficiencies of Treatment Barriers at the PRF

Symbol Anticipated Removal Efficiency

○ Poor = no significant removal (<20%)

◑ Fair = up to 60% removal

◕ Good = up to 90% removal

● Excellent = up to 100% removal

(Blank) No data available

2.3.3 HACCP Matrix Applications

The PRF is well equipped for the removal of multiple contaminants (see Appendix A); however some

additional barriers may be necessary in the future to meet potential new rules and Customer expectations.

The list of contaminants and associated limits in Appendix A may be used as a standalone reference to

inform monitoring activities, regulatory discussions, and other applications, as well as in combination



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with treatment barrier information to highlight contaminants with little to no removal capabilities at the

PRF. Furthermore, this information can be coupled with source water quality data to further inform the

identification of contaminants that pose high inherent risk in raw water and high residual risk in treated

water, if any. For example:

• To identify contaminants that are subject to little or no removal at the Peace River

Facility, one may limit Appendix A to only show contaminant rows with associated poor

overall removal by selecting the dropdown filter option in column O.

• To estimate the PRF’s ability to remove a given contaminant that may have been detected

in the source water or is the subject of increasing public interest, one may search the list of

hazards for the specific contaminant and view the associated treatment barrier

information.

• In the absence of source water data, one may anticipate the presence or absence of a given

contaminant in raw water by coupling knowledge of the watershed (e.g., land use types,

potential contamination site inventories) with hazard source information in column I.



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| Current Conditions in the Peace River Manasota Regional Water Supply System 3-1

Section 3. Current Conditions in the Peace River Manasota Regional

Water Supply System

Current conditions in the Authority’s Regional System were characterized using historical data from the

Authority and its Customers in response to the data requests provided in Appendix B. Section 3.1

describes how historical data were collected, summarized, and analyzed. Section 3.2 presents a summary

of finished water quality and a more detailed discussion of select water quality elements. For a

comprehensive presentation of current conditions in the Authority’s Regional System, refer to the Water

Quality Baseline Summary in Appendix C.

3.1 Historical Data Review using Business Intelligence Tools

Hazen submitted a data request to Authority staff and each Customer in November 2018. Copies of the

data requests are provided in Appendix B. The requested data included water quality data for raw, treated,

and delivered water; distribution system flushing logs; Customer complaint logs; and descriptions of

operational protocols. These data were used to characterize current conditions in the Regional System,

which are referred to as the water quality baseline. The data were reviewed, tabulated in Excel, and input

into Microsoft Power BI to enable dynamic exploration of historical data with efficient filtering and

visualization capabilities.

Microsoft Power BI is a business analytics service, which allows the user to transform data into

interactive visualizations to facilitate fast, informed decisions. Power query in Power BI allows the user to

combine, transform, and organize immense amounts of data in a fraction of the time compared with

traditional spreadsheet aggregation. The service can connect directly to a variety of different data sources

and provide real-time streaming and reporting. Microsoft Power BI is one of many Business Intelligence

tools that could be used to analyze large amounts of data. For the scope of this evaluation, Power BI was

used because it is a component of the Microsoft Office suite that the Authority has available for use,

which facilitates the sharing of generated Power BI reports. The organization and functionality of the

Power BI dashboards are described in detail in Appendix C.

3.2 Water Quality Baseline

3.2.1 Finished Water Quality Compliance Summary

Table 3-1 through Table 3-5 summarize the regulatory water quality criteria the Authority is required to

meet at the PRF, as well as the PRF’s performance relative to those limits using data from 2016, 2017,

and 2018 quarterly compliance reports provided by the Authority. Importantly, quarterly compliance

report data show that the Authority is in compliance with all Federal and State drinking water regulations,

which is also confirmed in the USEPA’s Enforcement and Compliance History Online (ECHO) system.2

2 https://echo.epa.gov/detailed-facility-report?fid=110000717626#pane3110000717626

https://echo.epa.gov/detailed-facility-report?fid=110000717626#pane3110000717626



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Selected water quality elements of current conditions in the Authority’s Regional System are discussed in

Sections 3.2.2 through 3.2.6 using exported graphics from the Water Quality Baseline Dashboard created

in Power BI. Discussed water quality elements span source water, treatment, and finished water. For a

comprehensive presentation of current conditions in the Regional System, refer to the Water Quality

Baseline Power BI file (Appendix C).

Table 3-1: Water Quality Criteria for Microorganisms

Contaminant Treatment Technique 1 Requirement PRF Results

Cryptosporidium Disinfection and filtration

Authority meets treatment

technique requirements set by

USEPA and FDEP

Giardia Lamblia Disinfection, filtration, and 3-log (99.9%)

removal/inactivation

Heterotrophic Plate Count (HPC) Disinfection, filtration, and no more than

500 bacterial colonies per milliliter

Legionella Disinfection and filtration

Total Coliforms

Disinfection, filtration, and no more than

5.0% samples total coliform-positive in a

month

Turbidity

Disinfection, filtration, all measurements

below 1 NTU, and 95% of measurements

less than or equal to 0.3 NTU

Viruses (Enteric) Disinfection, filtration, and 4-log (99.99%)

removal/inactivation

1 Treatment Technique (TT) defined by the USEPA as a required process intended to reduce the level of a

contaminant in drinking water



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Table 3-2: Water Quality Criteria for Disinfectants and Disinfection Byproducts

Contaminant Units MCL 1

PRF Results

Sampling Location

Result Range 2

(n = sample size)

Chloramines (as Cl2) mg/L 4.0 Finished Water 3.73 – 3.79

Chlorine (as Cl2) mg/L 4.0 No data; only required for systems using free chlorine as a

secondary disinfectant

Chlorine Dioxide (as ClO2) mg/L 0.8 No data; only required for water treatment plants that use

chlorine dioxide

Bromate mg/L 0.10 No data; only required for water treatment plants that use

ozone

Chlorite mg/L 1.0 No data; only required for water treatment plants that use

chlorine dioxide

Haloacetic Acids (HAA5) 3 mg/L 0.060

Finished Water 0.011 – 0.030 (n = 12)

Charlotte County Utility 10

(Point of Connection) 0.013 – 0.032 (n = 12)

Carlton 42 (Point of

Connection) 0.015 – 0.032 (n = 12)

Total Trihalomethanes

(TTHMs) 4 mg/L 0.080

Finished Water 0.025 – 0.043 (n = 12)

Charlotte County Utility 10

(Point of Connection) 0.024 – 0.047 (n = 12)

Carlton 42 (Point of

Connection) 0.028 – 0.045 (n = 12)

1 MCL = maximum contaminant level for finished drinking water 2 Result range from 2016 – 2018 historical water quality data in quarterly Stage 2 Reports or, for chloramines,

running annual average values given in 2016 – 2018 Consumer Confidence Reports 3 HAA5 includes monochloroacetic acid, trichloroacetic acid, dichloroacetic acid, monobromoacetic acid, and

dibromoacetic acid 4 TTHMs include trichloromethane (or chloroform), dibromochloromethane, bromodichloromethane, and

bromoform

Table 3-3: Water Quality Criteria for Inorganic Chemicals


PRF Results

Sampling Location

Result Range 2

(n = sample size)

Antimony mg/L 0.006 Entry point to the distribution

system 0.005 (n = 3)

Arsenic mg/L 0.010

Influent Raw Water 0.00069 – 0.01 (n = 35)

Finished Water 0.00069 – 0.002 (n = 38)

Asbestos (fiber > 10

micrometers)

million

fibers

per liter

7 Finished Water 0.12 – 0.19 (n = 3)

Barium mg/L 2 Finished Water 0.009 – 0.013 (n = 3)

Beryllium mg/L 0.004 Finished Water 0.000078 (n = 3)



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PRF Results

Sampling Location

Result Range 2

(n = sample size)

Cadmium mg/L 0.005 Finished Water 0.0009 (n = 3)

Chromium (Total) mg/L 0.1 Finished Water 0.002 – 0.003 (n = 3)

Copper mg/L 1.3 (Action

Level) Finished Water 0.007 – 0.013 (n = 3)

Cyanide (as Free

Cyanide) mg/L 0.2 Finished Water 0.005 (n = 3)

Fluoride mg/L 4.0 Finished Water 0.19 – 0.212 (n = 3)

Lead mg/L

0.015

(Action

Level)

Finished Water 0.00067 (n = 3)

Mercury mg/L 0.002 Finished Water 0.000198 (n = 3)

Nickel mg/L 0.1 Finished Water 0.0018 – 0.004 (n = 3)

Nitrate (as Nitrogen) mg/L 10 Finished Water 0.051 – 0.57 (n = 11)

Nitrite (as Nitrogen) mg/L 1 Finished Water 0.013 – 0.2 (n = 11)

Selenium mg/L 0.05 Finished Water 0.00157 (n=3)

Sodium mg/L 160

Influent Raw Water 13.5 – 30.5 (n = 35)

Finished Water 13.5 – 53.7 (n = 38)

Thallium mg/L 0.002 Finished Water 0.000981 – 0.00169 (n = 3)

1 MCL = maximum contaminant level for finished drinking water 2 Result range from 2016 – 2018 historical water quality data in quarterly compliance reports

Table 3-4: Water Quality Criteria for Organic Chemicals


PRF Results

Sampling Location Result Range 2

(n = sample size)

2,3,7,8-TCDD (Dioxin) mg/L 3 x 10-8 Finished Water (0.629 – 2.02) x 10-9 (n = 4)

2,4-D mg/L 0.07 Finished Water 0.000081 (n = 2)

2,4,5-TP (Silvex) mg/L 0.05 Finished Water 0.00016 (n = 2)

Acrylamide -

Treatment

Technique

Requirement

Only systems that use acrylamide and/or epichlorohydrin

must certify annually that the combination of dose and

monomer level does not exceed the specified levels 3

Alachlor mg/L 0.002 Finished Water 0.000034 (n = 2)

Atrazine mg/L 0.003 Finished Water 0.0006 (n = 2)



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PRF Results


(n = sample size)

Benzene mg/L 0.005 Finished Water 0.00005 (n = 2)

Benzo(a)pyrene (PAHs) mg/L 0.0002 Finished Water 0.000012 – 0.000013 (n = 2)

Carbofuran mg/L 0.04 Finished Water 0.00032 (n = 2)

Carbon Tetrachloride mg/L 0.005 Finished Water 0.00005 (n = 3)

Chlordane mg/L 0.002 Finished Water 0.000045 (n = 2)

Chlorobenzene mg/L 0.1 Finished Water 0.00005 (n = 3)

Dalapon mg/L 0.2 Finished Water 0.00089 (n = 2)

Di(2-ethylhexyl) adipate mg/L 0.4 Finished Water 0.00038 (n = 1)

Di(2-ethylhexyl) phthalate mg/L 0.006 Finished Water 0.0005 (n = 1)

1,2-Dibromo-3-

Chloropropane (DBCP) mg/L 0.0002 Finished Water 0.000014 (n = 2)

o-Dichlorobenzene mg/L 0.6 Finished Water 0.00005 (n = 3)

p-Dichlorobenzene mg/L 0.075 Finished Water 0.00005 (n = 3)

1,2-Dichloroethane mg/L 0.005 Finished Water 0.00005 (n = 3)

1,1-Dichloroethylene mg/L 0.007 Finished Water 0.00005 (n = 3)

cis-1,2-Dichloroethylene mg/L 0.07 Finished Water 0.00005 (n = 3)

trans-1,2-Dichloroethylene mg/L 0.1 Finished Water 0.00005 (n = 3)

DichloroMEThane mg/L 0.005 Finished Water 0.00005 (n = 3)

1,2-Dichloropropane mg/L 0.005 Finished Water 0.00005 (n = 3)

Dinoseb mg/L 0.007 Finished Water 0.00016 (n = 2)

Diquat mg/L 0.02 Finished Water 0.0003 (n = 2)

Endothall mg/L 0.1 Finished Water 0.0043 (n = 2)

Endrin mg/L 0.002 Finished Water 0.0000067 (n = 2)

Epichlorohydrin mg/L

Treatment

Technique

Requirement

Systems that use acrylamide and/or epichlorohydrin

must certify annually that the combination of dose and

monomer level does not exceed the specified levels 3

Ethylbenzene mg/L 0.7 Finished Water 0.00005 (n = 3)

Ethylene Dibromide mg/L 0.00005 Finished Water 0.00001 (n = 2)



Final Report



PRF Results


(n = sample size)

Glyphosate mg/L 0.7 Finished Water 0.0042 (n = 2)

Heptachlor mg/L 0.0004 Finished Water 0.000011 (n = 2)

Heptachlor epoxide mg/L 0.0002 Finished Water 0.0000029 (n = 2)

Hexachlorobenzene mg/L 0.001 Finished Water 0.000018 (n = 2)

Hexachlorocyclopentadiene mg/L 0.05 Finished Water 0.000031 (n = 2)

Lindane mg/L 0.0002 Finished Water 0.0000029 (n = 2)

METhoxychlor mg/L 0.04 Finished Water 0.000049 (n = 2)

Oxamyl (Vydate) mg/L 0.2 Finished Water 0.00055 (n = 2)

Plychlorinated Biphenyls

(PCBs) mg/L 0.0005 Finished Water 0.000077 (n = 2)

Pentachlorophenol mg/L 0.001 Finished Water 0.00003 (n = 2)

Picloram mg/L 0.5 Finished Water 0.000094 (n = 2)

Simazine mg/L 0.004 Finished Water 0.000066 (n = 2)

Styrene mg/L 0.1 Finished Water 0.00005 (n = 3)

Tetrachloroethylene mg/L 0.005 Finished Water 0.00005 (n = 3)

Toluene mg/L 1 Finished Water 0.00005 (n = 3)

Toxaphene mg/L 0.003 Finished Water 0.00058 (n = 2)

1,2,4-Trichlorobenzene mg/L 0.07 Finished Water 0.00005 (n = 3)

1,1,1-Trichloroethane mg/L 0.2 Finished Water 0.00005 (n = 3)

1,1,2-Trichloroethane mg/L 0.005 Finished Water 0.00005 (n = 3)

Trichloroethylene mg/L 0.005 Finished Water 0.00005 (n = 3)

Vinyl Chloride mg/L 0.002 Finished Water 0.00005 (n = 3)

Xylenes (Total) mg/L 10 Finished Water 0.00005 (n = 3)

1 MCL = maximum contaminant level for finished drinking water 2 Result range from 2016 – 2018 historical water quality data in quarterly compliance reports 3 Specified levels: acrylamide = 0.05 percent dosed at 1 mg/L; epichlorohydrin = 0.01 percent dosed at 20 mg/L



Final Report


Table 3-5: Water Quality Criteria for Radionuclides


PRF Results

Sampling Location

Result Range 2

(n = sample size)

Alpha Particles

picocuries

per liter

(pCi/L)

15 Finished Water 1 – 8.9

Beta Particles and

Photon Emitters

millirems

per year 4

Monitoring is not required; only vulnerable systems must

conduct monitoring

Radium 226 and

Radium 228

(Combined)

pCi/L 5 Finished Water 0.9 – 2

Uranium µg/L 30

No data in the 2016 – 2018 timeframe because reduced

monitoring only requires one sample every 3 to 9 years

depending on initial monitoring results

1 MCL = maximum contaminant level for finished drinking water 2 Result range from 2016 – 2018 historical water quality data in quarterly compliance reports

3.2.2 Raw Water Quality and Variability

The quality of finished drinking water at the PRF is entirely dependent on raw water quality and treatment

performance. Raw water quality is particularly important for constituents that do not have a treatment

barrier at the PRF, such as total dissolved solids (TDS). Figure 3-1:highlights the importance of the

Authority’s reservoir system for maintaining raw water TDS concentrations below the secondary

maximum contaminant level (MCL) of 500 mg/L. Figure 3-1: shows TDS concentrations in raw river

water over time, which are highly variable and often far exceed the secondary MCL, as compared with

TDS concentrations in raw reservoir water, which are consistently below the secondary MCL. River water

TDS values vary widely throughout the year based on rainfall and river flow, thus making river water

unavailable for parts of the year due to water quality. The reservoir allows the Authority to avoid

withdrawing river water when the TDS levels are high and to rely on the reservoir during those times; low

TDS concentrations in the river tend to co-occur with high river flows, thus meaning that harvested river

water is generally low in TDS. Figure 3-2: shows that the TDS concentrations in the reservoir are also

subject to seasonality, although the magnitude of variability is substantially reduced relative to river

water.

The water quality mitigation role of the reservoir is also illustrated by a comparison of historical color

concentrations in raw river and reservoir water, as shown in Figure 3-3:. Color is an important raw water

quality parameter because it is an indicator of TOC concentrations, which drive chemical demands,

clarification, filter performance, and disinfection byproduct formation at the PRF. Similar to TDS, both

raw river and reservoir water show variability in color concentrations, but the magnitude of variability is

greater in river water than reservoir water. Although river water is transferred to the reservoir system

during the wet season when color concentrations tend to be high, the reservoir system’s large storage

volume serves as a buffer against event-induced, water quality flashiness. Newly collected river and

reservoir water TOC data at different river flow rates show the same trends as color, as further discussed

in Section 3.2.6.



Final Report


Figure 3-1: TDS Concentrations in Raw River and Reservoir (Pond) Water

Figure 3-2: TDS Concentrations in Raw Reservoir (Pond) Water

River flow shown for context




Final Report


Figure 3-3: Color Concentrations in Raw River and Reservoir (Pond) Water

Influent water quality to the PRF is not only a function of river water quality, but also the extent and

associated quality of withdrawals from the ASR system. For example, Figure 3-4: shows historical total

hardness concentrations in raw reservoir water (green series) as compared with withdrawals from the

ASR system (purple series), which are delivered to the reservoir system for blending prior to treatment at

the PRF. These data show that the total hardness concentrations in the reservoir tended to increase when

ASR contributions to the reservoir were more prevalent and the river water contributions to the reservoir

system were low or paused.




Final Report


Figure 3-4: Total Hardness Concentrations in Raw Reservoir (Pond) Water

3.2.3 Disinfection Byproduct Formation

The Water Quality Baseline Dashboard can be used to explore relationships between various water

quality parameters at the PRF and the Customer distribution system. As an example, Figure 3-5 highlights

the importance of ensuring TOC removal performance at the PRF for continuous compliance with THM

limits. Figure 3-5: shows TOC and disinfection byproduct (DBP) concentrations in finished water at the

PRF. These data show that finished water TOC concentrations are fairly stable, generally ranging from

2.5 to 4.5 mg/L, and that finished water DBP concentrations are consistently below associated regulatory

limits of 80 µg/L for trihalomethanes (THMs) and 60 µg/L for haloacetic acids (HAAs). These data also

show that THM concentrations tend to correlate with finished water TOC concentrations, whereas HAA

concentrations are consistently low and less dependent on finished water TOC concentrations. The

compounds that comprise TOC can serve as precursor material for both THMs and HAAs; however, the

stronger relationship between TOC and THMs is influenced by the pH range in which the PRF operates

(finished water pH generally greater than 8.0).

Figure 3-6 shows that THM formation largely takes place at the PRF, as opposed to in the distribution

system because of the Authority’s use of chloramines. Although the Authority has several (points of

connection) POCs with its Customers, DBPs and other water quality parameters are measured at two

specific POCs, Carlton 42” and Charlotte County Utility 10”, in accordance with their Stage 2 Monitoring

Plan.



Final Report


Figure 3-5: TOC (top) and Disinfectant Byproduct (bottom) Concentrations in Finished Water



Final Report


Figure 3-6: Trihalomethane Concentrations in Finished Water and at Points of Connection

3.2.4 Disinfectant Residual

Figure 3-7 presents the relationship between TOC concentrations in finished water at the PRF and

disinfectant residual stability within the Customer’s distribution system. This is an important relationship

because disinfectant stability is impacted by many factors, one of which is TOC because TOC contributes

to chlorine demand, as well as supports biofilm formation. In the case of the Authority, Figure 3-7 shows

that the observed TOC variability of finished water at the PRF does not have a substantial impact on

chlorine residual in finished water and/or at two points of connection. It is important to note that this lack

of an observed relationship between finished water TOC and residual stability may be attributable to the

fact that finished water TOC has shown minimal variability within the given time period.

River water diversions to reservoir



Final Report


Figure 3-7: Disinfectant (as Cl2) Concentrations in Finished Water and at Points of Connection

(top) and TOC Concentrations in Finished Water (bottom)

3.2.5 Unregulated Contaminant Monitoring Rule Results

The Authority and its Customers are conducting sampling from 2018 to 2020 in accordance with the

Fourth Unregulated Contaminant Monitoring Rule (UCMR 4), which is described in detail in Section

2.2.1.1. The sampling schedule for UCMR 4 is provided in Table 3-6. Although the Authority is not

required to collect data under UCMR 4, a sampling plan was developed to collect data that coincides with

Customer collection schedules to compare data. The UCMR 4 results collected thus far by the Authority

are summarized below in Table 3-7. To date, the Authority’s UCMR 4 results show no constituent





Final Report


concentrations greater than the associated reference concentration. Reference concentrations are defined

by the USEPA as health-based water quality limits that provide context for the detection of a UCMR

contaminant; reference concentrations do not represent regulatory values or action levels.

Table 3-6: UCMR 4 Sampling Schedule by Agency

Agency 2018 2019 2020

Charlotte County

AM3 locations- Entry

Points APR-JUL weeks 2

& 4 each month

AM1 (Entry Points) & AM2

(Distribution points)

March, June, September,

December 2019

None

DeSoto County None None None

Manatee County AM1, AM2, AM3

all locations in 2018 None None

City of North Port

AM1 (Entry Points) & AM2

(Distribution points) Feb,

May, August, November

2018 on 3rd Tuesday of

each Month

AM3 locations- Entry

Points AUG - NOV weeks

1 & 3 each month

Punta Gorda Unknown Unknown Unknown

Sarasota County None None

AM1 & AM2 - March,

June, September,

December AM3- March -

June Weeks 1 & 3

PRMRWSA AM1, AM2, AM3 all

locations

AM1, AM2, AM3 all

locations

AM1, AM2, AM3 all

locations

Table 3-7: Summary of Existing Authority UCMR 4 Results as of October 2019

Sample

Location Analyte

Number

of

Results

Units MRL 1 Min

Result

Avg

Result

Max

Result

Ref.

Conc. 2

Raw Source

Water

Cryptosporidium 1 oocysts/

L 0.091 0.091 --

Giardia 1 cysts/L 0.091 0.091 --

Facility

Influent

Bromide 8 ug/L 10 - 20 74.3 83.8 93.6 --

Total organic carbon

(TOC) 8 mg/L 0.5 - 1 12.2 13.2 14.6 --

Carlton 42”

(Point of

Connection)

Bromochloroacetic acid 6 ug/L 0.3 - 1 4 4.6 5.14 --

Bromodichloroacetic

acid 6 ug/L 0.5 - 1 2.41 4.1 4.7 --

Chlorodibromoacetic

acid 6 ug/L 0.3 - 2 0.508 1.4 2 --

Dibromoacetic acid 6 ug/L 0.3 - 1 0.851 1.0 1.04 --

Dichloroacetic acid 6 ug/L 0.2 - 1 8.7 11.6 15.3 --

Monobromoacetic acid 6 ug/L 0.3 - 1 0.3 0.7 1 --

Monochloroacetic acid 6 ug/L 2 2 2.0 2 --



Final Report


Sample

Location Analyte

Number

of

Results

Units MRL 1 Min

Result

Avg

Result

Max

Result

Ref.

Conc. 2

Tribromoacetic acid 6 ug/L 2 - 4 2 3.0 4 --

Trichloroacetic acid 6 ug/L 0.5 - 1 3.2 5.8 9.85 --

Total HAA5 6 ug/L -- 12.9 18.1 26.062 60

Charlotte 10”

(Point of

Connection”

Bromochloroacetic acid 6 ug/L 0.3 - 1 4 4.6 5.14 --

Bromodichloroacetic

acid 6 ug/L 0.5 - 1 2.77 4.1 5.4 --

Chlorodibromoacetic

acid 6 ug/L 0.3 - 2 0.552 1.5 2.8 --

Dibromoacetic acid 6 ug/L 0.3 - 1 0.779 1.0 1.1 --



Monochloroacetic acid 6 ug/L 2 2 2.0 2 --



Total HAA5 6 ug/L --- 12.7 17.6 24.622 60

Tank 1 Entry

Neodymium-143 8 cps 10000 10000 10000 10000 --

Samarium-147 8 cps 10000 10000 10000 10000 --

1-Butanol 8 ug/L 2 2 2.0 8 700

2-Methoxyethanol 8 ug/L 0.4 0.4 0.4 0.4 --

2-Propen-1-ol 8 ug/L 0.5 0.5 0.5 0.5 35

alpha-

Hexachlorocyclohexane 8 ug/L 0.01 0.01 0.01 0.01

0.006 to

0.6

Anatoxin-a 12 ug/L 0.03 0.03 0.03 0.03 --

Bromochloroacetic acid 6 ug/L 0.3 - 1 3.9 4.4 4.95 --

Bromodichloroacetic

acid 6

ug/L 0.5 - 1 3.15 4.5 5.2 --

Butylated

hydroxyanisole 8

ug/L 0.03 0.03 0.03 0.03 --

Chlorodibromoacetic

acid 6

ug/L 0.3 - 2 0.54 1.4 2.2 --

Chlorpyrifos 8 ug/L 0.03 0.03 0.03 0.03 2

cis-Permethrin 8 ug/L

0.0109 0.0109 0.0109 0.0109 3.344 to

334.4

Cylindrospermopsin 12 ug/L 0.09 0.09 0.09 0.09 0.7

Dibromoacetic acid 6 ug/L 0.3 - 1 0.706 0.9 1 --


Dimethipin 8 ug/L 0.2 0.2 0.2 0.2 140

Ethoprop 8 ug/L

0.03 0.03 0.03 0.03 1.14 to

114

Germanium 8 ug/L 0.3 - 1 0.3 0.6 1 --

Manganese 8 ug/L 0.4 - 2 1.32 3.3 5.68 300




Final Report


Sample

Location Analyte

Number

of

Results

Units MRL 1 Min

Result

Avg

Result

Max

Result

Ref.

Conc. 2

Monochloroacetic acid 6 ug/L 2 2 2.6 3.8 --

o-Toluidine 8 ug/L 0.007 0.007 0.007 0.007 --

Oxyfluorfen 8 ug/L 0.05 0.05 0.05 0.05 200

Permethrin, cis & trans 8 ug/L

0.04 0.04 0.04 0.04 3.344 to

334.4

Profenofos 8 ug/L 0.3 0.3 0.3 0.3 0.3

Quinoline 8 ug/L 0.02 0.02 0.02 0.02 0.01 to

1

Tebuconazole 8 ug/L 0.2 0.2 0.2 0.2 190

Total Microcystins &

Nodularins 12 ug/L 0.3 0.3 0.3 0.3 0.3

trans-Permethrin 8 ug/L

0.029 0.029 0.029 0.029 3.344 to

334.4


Tribufos 8 ug/L 0.07 0.07 0.07 0.07 0.6


Total HAA5 6 ug/L -- 12.1 19.1 25.304 60

1 MRL = minimum reporting level 2 Ref. Conc. = Reference Concentration, which is a health-based concentration provided by the USEPA that

provides context for the detection of a UCMR contaminant; reference concentrations do not represent regulatory

limits or action levels

3.2.6 Newly Collected Water Quality Data for the Water Quality Master Plan

Additional water quality sampling was conducted as part of this WQMP to compliment the historical

water quality data that was provided by the Authority and its Customers. These additional data were

collected to quantify the relationship between TOC, DBP formation, and chloramine stability, as well as

inform the extent to which TOC is amenable to additional removal by various treatment processes, as

further discussed in Section 4. The detailed sampling plan is provided in Appendix D.

Sampling events were scheduled for multiple times throughout the year to capture seasonal variability

because TOC concentrations and quality tend to be a function of precipitation, temperature, and

watershed activity. For each sampling event, sample locations included the following:

• Raw river water at a location that is representative of the intake;

• Raw reservoir water at a location that is representative of reservoir water that is delivered

to the PRF;

• Raw, withdrawn ASR water at a location that is representative of recovered water from

the ASR system, if available at the time of the sampling event;

• Post-sedimentation water downstream of flocculation and sedimentation basins, and

upstream of sodium hypochlorite addition in one of the three treatment trains; and

• Finished water downstream of filtration and caustic addition in one of the three treatment

trains.



Final Report


For each sampling event, the following analyses were conducted:

• Disinfection byproduct formation potential tests (DBPFPs),

• Chloramine decay monitoring,

• TOC and ultraviolet absorbance at 254 nm (UV254),

• Fluorescence excitation-emission matrix (EEM) scans, and

• Bromide, barium, and silica analyses.

The DBPFP testing and chloramine decay monitoring were conducted to better understand the

distribution system implications of existing water quality produced by the PRF, as well as to estimate the

potential benefits resulting from increased TOC removal, as discussed in Section 4. Figure 3-8 presents

the DBPFP results, including four THM species and five HAA species, for finished water samples as a

result of finished water TOC concentrations. It should be noted that the Authority practices secondary

disinfection with the use of chloramine at the PRF, not free chlorine; however, DBPFPs were conducted

as described in Standard Method 5710 with free chlorine. Free chlorine was used in the DBPFPs to more

clearly observe the relationship between DBP production and finished water quality because DBP

formation is more sensitive to changes in TOC under chlorination relative to chloramination. The

observed trends in Figure 3-8 may be translated to the Authority system, but the magnitude of observed

DBP formation potential concentrations in DBPFPs is higher than that observed in the Authority system

(Figure 3-6) due to the difference in disinfectants. The results in Figure 3-8 demonstrate the importance of

TOC removal at the PRF because THM concentrations, and to a lesser extent HAA concentrations,

increase as a function of finished water TOC concentrations, which is consistent with the observed

historical data trends (Figure 3-5).

Figure 3-8: Disinfection Byproduct Formation Potential Test Results

Figure 3-9 shows the results for chloramine decay testing that was conducted at the PRF using grab

samples that were stored at room temperature and in the dark. Finished water samples, which had been

previously subject to chloramination at the PRF, were collected and monitored for chloramine residual

decay over the course of seven days. The results in Figure 3-9 suggest that the stability of the chloramine

0

20

40

60

80

100

120

140

160

180

200

0 1 2 3 4 5

DB

P F

orm

ation P

ote

ntial (µ

g/L

)

Finished Water TOC Concentration (mg/L)

THMs HAAs



Final Report


residual leaving the PRF is fairly consistent over time, as the chloramine decay dynamics look similar for

each of the four sampling events. It should be noted, however, that finished water TOC concentrations

only ranged from 2.58 to 3.1 mg/L over these sampling events and this minimal TOC variability may

have been too slight to observe an associated impact on chloramine stability. It should also be noted that

the results shown in Figure 3-9 are intended to serve as an indicator of chloramine stability variability

over time, but not representative of the actual rate of decay in the distribution system because conditions

in the distribution system are different than the experimental conditions employed herein.

Figure 3-9: Chloramine Decay Test Results

Table 3-8 and Figure 3-10 present the TOC, UV254, and SUVA254 results. Table 3-9 presents the EEM

scans for raw river and reservoir water; and Table 3-10 presents the bromide, silica, and barium results.

These data were collected to inform the suitability of various treatment processes for the removal of

additional TOC at the PRF based on the character of the TOC and other water quality parameters, as

further discussed in Section 4.

The results in Table 3-8 show the character and concentration of natural organic matter across sample

locations and over time. TOC measurements represent the concentration of natural organic matter,

whereas UV254 reflects the character of the natural organic matter because the higher the UV254 reading,

the higher the aromaticity of the sample’s TOC. Lastly, SUVA254 is the ratio of UV254 to TOC, and has

been shown to be strongly correlated with the hydrophobic organic acid fraction of dissolved organic

matter. The fluorescence results in Table 3-9 also inform the character and concentration of natural

organic matter because certain fractions of natural organic matter are more fluorescent than others,

particularly in certain regions of EEMs. Taken together, the newly collected water quality data provide

the following findings:

• Variability in raw water TOC concentrations is much greater in the Peace River than in

the reservoir system due to the dampening effect of the reservoir. Thus, the reservoir

system enables the delivery of influent flows with fairly consistent TOC concentrations to

the PRF and the production of finished water with consistent and low TOC concentrations.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0 20 40 60 80

Chlo

ram

ine C

oncentr

ation (

mg/L

)

Incubation Time (hrs)

5/29/2019 6/20/2019 8/5/2019 8/20/2019



Final Report


• Natural organic matter in Peace River are not only variable from a quantity standpoint

(i.e., TOC concentrations), but also from a quality standpoint considering observed

temporal variability in SUVA254. SUVA254 readings were higher in June and August

sampling events than in March and May sampling events, thus indicating that seasonal

factors (e.g., increased precipitation and temperatures) not only increase the delivery of

natural organic matter to the Peace River, but specifically natural organic matter that may

be characterized as aromatic. It is preferred that influent TOC to the PRF be aromatic

because aromatic TOC tends to be more amenable to removal by chemical coagulation.

The EEMs in Table 3-9 can be interpreted by integrating the cumulative fluorescence within the

designated regions of the EEMs (fluorescence regional integration or FRI) because fluorescence in those

areas is indicative of certain types of organic compounds. The percent contribution of each region to a

sample’s total fluorescence across the PRF treatment train is presented in Figure 3-11: Raw Water FRI

Results and Figure 3-12. These data show that raw and treated water fluorescence is mostly attributed to

Regions II and III, which are associated with fulvic- and humic-like (i.e., aromatic) organic compounds.

• For every sampling event, the PRF demonstrated excellent TOC removal. Finished water

TOC concentrations were 76.6% to 88.8% lower than raw river water concentrations and

70.8% to 77.1% lower than raw reservoir water concentrations across the five sampling

events.

• The major treatment barrier for TOC at the PRF is coagulation / flocculation /

sedimentation, which resulted in 67.5% to 76.3% removal of TOC and 85% to 90.2%

removal of UV254 relative to raw reservoir water. The increased removal of UV254 relative

to TOC indicates that this treatment barrier achieves preferential removal of aromatic

natural organic matter. These results also align with the fluorescence results, as

fluorophores in Regions II and III are associated with fulvic- and humic-like compounds,

which are typically characterized as aromatic.

• The FRI results for finished water in Figure 3-12 suggest that if additional TOC removal

is needed, the selected treatment process should be one that targets humic- and fulvic-like

compounds because they are the dominant components in residual TOC.

• The silica, bromide, and barium data shown in Table 3-10 were collected specifically to

inform the extent to which certain treatment enhancements may be appropriate for the

PRF for increased TOC removal. Barium and silica can present a challenge for membrane-

based treatment processes because these constituents can precipitate out of solution and

cause membrane scaling. Bromide can be problematic for treatment enhancements

involving ozonation because bromide is converted to bromate upon ozonation, which is a

regulated disinfection byproduct. The relevance and treatment implications of the detected

silica, bromide, and barium concentrations at PRF are discussed in Section 4.

Table 3-8: Natural Organic Matter Parameters Summary

Sample

Date

Sample

Time

Sample

Description

TOC [SM5310B] UV254 [SM5910B] SUVA

Result Units Result Units Result Units

3/11/2019 8:00 AM Raw river

water

15.8 mg/L 0.650 cm-1 4.11 L/mg-cm

5/29/2019 7:20 AM 11.3 mg/L 0.402 cm-1 3.56 L/mg-cm



Final Report


Sample

Date

Sample

Time

Sample

Description

TOC [SM5310B] UV254 [SM5910B] SUVA


6/20/2019 7:15 AM 18.2 mg/L 0.873 cm-1 4.80 L/mg-cm

8/5/2019 9:40 AM 23.9 mg/L 1.247 cm-1 5.22 L/mg-cm

8/20/2019 8:30 AM 27.7 mg/L 1.619 cm-1 5.85 L/mg-cm

3/11/2019 1:40 PM

Raw reservoir

water

12.6 mg/L 0.461 cm-1 3.66 L/mg-cm

5/29/2019 7:45 AM 11.0 mg/L 0.397 cm-1 3.61 L/mg-cm

6/20/2019 7:35 AM 11.4 mg/L 0.378 cm-1 3.32 L/mg-cm

8/5/2019 10:00

AM 11.5 mg/L 0.396 cm-1 3.45 L/mg-cm

8/20/2019 8:15 AM 12.6 mg/L 0.500 cm-1 3.97 L/mg-cm

3/11/2019 2:00 PM

Post-

sedimentation

4.1 mg/L 0.069 cm-1 1.69 L/mg-cm

5/29/2019 8:20 AM 2.7 mg/L 0.039 cm-1 1.46 L/mg-cm

6/20/2019 8:20 AM 2.7 mg/L 0.039 cm-1 1.46 L/mg-cm

8/5/2019 10:40

AM 2.9 mg/L 0.041 cm-1 1.43 L/mg-cm

8/20/2019 9:00 AM 3.3 mg/L 0.052 cm-1 1.60 L/mg-cm

3/11/2019 2:30 PM

Finished

water

3.68 mg/L 0.080 cm-1 2.16 L/mg-cm

5/29/2019 7:20 AM 2.58 mg/L 0.057 cm-1 2.20 L/mg-cm

6/20/2019 8:55 AM 2.61 mg/L 0.056 cm-1 2.15 L/mg-cm

8/5/2019 11:00

AM 2.67 mg/L 0.057 cm-1 2.12 L/mg-cm

8/20/2019 9:15 AM 3.1 mg/L 0.067 cm-1 2.17 L/mg-cm

a)

0

5

10

15

20

25

30

March '19 May '19 June '19 August '19 August '19

TO

C C

oncentr

ation,

mg/L

Raw River

Raw Reservoir

Post-sedimentation

Finished



Final Report


b)

c)

Figure 3-10: a) TOC, b) UV254, and c) SUVA254 Concentrations Across the PRF System

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8


UV

254,

1/c

m

Raw River

Raw Reservoir

Post-sedimentation

Finished

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0


SU

VA

254,

L/m

g-c

m

Raw River

Raw Reservoir

Post-sedimentation

Finished



Final Report


Table 3-9: Excitation-Emission Matrix Raw Water Test Results

Legend

Le

ge

nd

Region I = Microbial byproducts, proteins, biopolymers

Region II =

Fulvic-like compounds Region III =

Humic-like compounds

Dat

e

Raw River Water Raw Reservoir Water

Ma

y 2

9,

20

19

Ju

ne

20

, 20

19



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Da

te


Au

gu

st

5, 2

019

Au

gu

st

20,

201

9



Final Report


Figure 3-11: Raw Water FRI Results

6% 7% 5% 5% 5% 7% 8% 8% 7% 7%

44%44%

43%

44% 43%

45% 45%45% 45% 45%

50%

48%

52%

51%

52%

48%47%

47%47%

49%

15.8

11.3

18.2

23.9

27.7

12.6

11.0 11.4 11.512.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

0

20000

40000

60000

80000

100000

120000

140000

160000

13-Mar 29-May 20-Jun 9-Aug 21-Aug 13-Mar 29-May 20-Jun 9-Aug 21-Aug


TO

C (

mg/L

)

FR

I re

sult (

au)

Region I Region II Region III TOC (mg/L)



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Figure 3-12: Treated Water FRI Results

Table 3-10: Inorganic Water Quality Parameters Summary

Sample

Date

Sample

Time

Sample

Description

Silica, Total [200.7] Bromide [300.0] Barium [200.7]


3/11/2019 8:00 AM

Raw river

water

7999 µg/L 0.256 mg/L 14.4 µg/L

5/29/2019 7:20 AM 3480 µg/L 0.044 mg/L 15.5 µg/L

6/20/2019 7:15 AM 5413 µg/L 0.072 mg/L 14.3 µg/L

8/5/2019 9:40 AM 6765 µg/L 0.009 mg/L 9 µg/L

8/20/2019 8:30 AM 6739 µg/L 0.056 mg/L 6.5 µg/L

3/11/2019 1:40 PM

Raw

reservoir

water

1156 µg/L 0.093 mg/L 10.9 µg/L

5/29/2019 7:45 AM 812 µg/L 0.044 mg/L 12.2 µg/L

6/20/2019 7:35 AM 240 µg/L 0.085 mg/L 8.3 µg/L

8/5/2019 10:00 AM 1207 µg/L 0.085 mg/L 9.2 µg/L

8/20/2019 8:15 AM 2361 µg/L 0.054 mg/L 10.3 µg/L

3/11/2019 2:30 PM

Finished

water

558 µg/L 0.177 mg/L 12 µg/L

5/29/2019 7:20 AM 71 µg/L 0.044 mg/L 17 µg/L

6/20/2019 8:55 AM 110 µg/L 0.454 mg/L 17 µg/L

8/5/2019 11:00 AM 763 µg/L 0.349 mg/L 15.1 µg/L

8/20/2019 9:15 AM 1606 µg/L 0.07 mg/L 12.3 µg/L

6% 7% 5% 5% 5% 7% 8% 8% 7% 7%

44%

44%43%

44%

43% 45%

45%45% 45%

45%

50%

48%

52%

51%

52% 48%

47%

47%47%

49%

4.06

2.68 2.662.89

3.28

3.68

2.58 2.61 2.67

3.09

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0

1000

2000

3000

4000

5000

6000

7000

8000

13-Mar 29-May 20-Jun 9-Aug 21-Aug 13-Mar 29-May 20-Jun 9-Aug 21-Aug

Post-Sedimentation Finished Water

TO

C (

mg/L

)

FR

I re

sult (

au)

Region I Region II Region III TOC (mg/L)



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3.3 Operational Baseline

This WQMP describes the operational baseline with respect to four major areas: source water withdrawal

protocols practiced by the Authority, and disinfection, flushing, and corrosion control protocols practiced

by the Authority and its Customers. Current conditions for source water withdrawals and disinfection are

discussed in this section; current conditions for flushing and corrosion control are discussed in Sections 4

and 5, respectively.

3.3.1 Source Water Withdrawal Protocols

3.3.1.1 Peace River Withdrawals

The Authority is permitted to withdraw water from the Peace River and pump those withdrawals to to the

reservoir system. The quantities withdrawn by the Authority from the Peace River are limited by a

diversion schedule in the Authority’s Water Use Permit, which allows for up to 258 MGD to be

withdrawn when flows are high. The withdrawal schedule ensures that the Authority’s use of water does

not adversely affect freshwater flows needed to support the downstream Charlotte Harbor Estuary.

Additionally, the Authority considers algae counts and TDS concentrations in the river as part of the

decision to withdraw water (as described below) to avoid source water quality challenges that are not

easily addressed with existing treatment at the PRF.

• The Authority aims to minimize river water withdrawals when algae counts are high in

order to avoid increased concentrations of algal toxins in raw and finished water; however,

algae has not been a major constraint on withdrawals historically, as higher algae counts

generally only occur for short periods of time following heavy rains in the early part of the

wet season when large amounts of debris and organic material are being flushed through

the system. After the initial wet season flush, water quality with respect to algae tends to

stabilize.

• The Authority targets a maximum TDS concentration of 400 mg/L in river water for

withdrawals to maintain the best possible water quality in the reservoirs and thus avoid the

need for TDS removal during treatment. When river flows are high, TDS concentrations

are low; when river flows are low, TDS concentrations are high and cannot be reduced by

existing treatment barriers at the PRF. Storage levels in the reservoir are critical for

determining the extent to which water quality concerns limit withdrawals from the river.

When more water is available in storage, Authority staff have more freedom to be

selective about the water quality that is withdrawn.

Historical water quality trends suggest that additional water quality-based constraints on Peace River

diversions to the reservoir system may benefit influent water quality to the PRF. For example, influent

TOC concentrations drive chemical demands, clarification, filter performance, and disinfection byproduct

formation at the PRF. Operational requirements and treated water quality generally benefit from low

influent TOC concentrations; however, the nature of Peace River dynamics is that TOC concentrations

tend to be high when river flows are high, thus TOC concentrations are high when water is available for

diversion (see similar temporal variability of river color concentrations and flow in Figure 3-3).

Accordingly, the Authority could consider limiting withdrawals due to high river TOC concentrations in



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order to limit reservoir TOC concentrations despite river flow being available for diversion. This

consideration is particularly relevant to the Authority because TOC peaks are anticipated to be short-

lived, thus meaning that TOC peaks might be avoided with minimal sacrifices in withdrawn quantities.

Under current source water withdrawal protocols, river water is withdrawn as a function of availability

and TDS, thus meaning that TOC peaks are likely diverted to the reservoir because they coincide with

periods of availability. To demonstrate this point, Figure 3-13 shows that reservoir water TOC

concentrations tend to be positively correlated with river water diversions to the reservoir.

Figure 3-13: TOC Concentrations in Reservoir (Pond) Water

3.3.1.2 Aquifer Storage and Recovery

The PRF’s ASR system includes 21 wells that have the capacity to store over 6 billion gallons. Fully

treated water that meets drinking water standards is injected and stored, primarily in the Suwannee

Limestone formation in the Upper Floridan Aquifer. ASR recharge may take place when excess raw water

and treatment capacity are available. The maximum recharge capacity is the difference between Customer

demand and the 51 MGD of treatment capacity at the PRF.

In times of low river flow and low water storage in the reservoirs, water is recovered from the ASR

system and discharged to the Authority’s reservoir system. Recovered water is then fully retreated again

at the PRF. The decision to recover water from the ASR system during the dry season is driven by the

amount of water in reservoir storage, river flow, and the time of year.

3.3.2 Disinfection Protocols

Distributed water from the PRF is fully treated, including the addition of sodium hypochlorite for primary

disinfection and chloramine (sodium hypochorite and ammonium hydroxide) for secondary disinfection.

Outside of the regional system, Customers may have chemical feed facilities for disinfection “trimming”,

during which excess free ammonia is converted to chloramine and the total chlorine residual is boosted to




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a target concentration. Each Customer establishes and implements their own trimming protocol, which are

described in Table 3-11: Customer Disinfection Trimming Protocols.

Table 3-11: Customer Disinfection Trimming Protocols

Agency Trimming Protocol

Charlotte County

Five booster stations; influent total chlorine residual, monochloramine, and free

ammonia are measured with online analyzers and used to control chemical feed

rates; sodium hypochlorite (12.5%) and ammonium sulfate (40%) are injected at

a ratio of approximately 8 to 1.

DeSoto County Chlorine and ammonia added at County South booster pump stations to achieve

a target residual of 5.5 mg/L

Englewood Information not received

Manatee County No disinfectant boosting practiced in the distribution system

City of North Port Chlorine and ammonia added at booster pump stations to achieve a target

residual

Punta Gorda Chlorine boosted at two remote sites to maintain 1.5 to 2.0 mg/L in the storage

tank

Sarasota County

Sodium hypochlorite and ammonium sulfate added to product at Carlton Water

Treatment Plant and received water from the PRF prior to ground storage tanks;

two booster stations for sodium hypochlorite and ammonium sulfate addition in

the distribution system

In summary, the Authority diverts water from the Peace River to the reservoir system in accordance with

their WUP Withdrawal Schedule, as well as using daily water quality monitoring of parameters, such as

Total Dissolved Solids and algae counts, as a tool to maximize the quality of source water withdrawals,

whenever possible. Historical water quality trends suggest that additional water quality-based constraints

on Peace River diversions to the reservoir system may further improve influent water quality to the PRF,

such as those that would minimize river withdrawals when TOC is peaking. Additionally, the Authority

benefits from an ASR system in which up to 6.3 billion gallons of fully treated water from the PRF may

be stored for later re-treatment and use. Operational considerations could include increasing the use of

this low TOC resource to blend during periods of higher TOC in the river/surface water system to

mitigate Reservoir TOC.

Distributed water from the PRF is treated with sodium hypochlorite and ammonium hydroxide for

secondary disinfection using chloramines. Disinfection byproducts sampling results indicate the

Authority’s disinfection protocols achieve excellent results in minimizing DBP formation at the PRF

effluent and at the POCs with Customer’s distribution systems. The disinfectant residual may be

augmented by Customers after POC’s, depending on their preference and distribution system profile. It is

recommended that Authority and Customer staffs continue active communications regarding disinfection

practices and distribution system boosting protocols.



Final Report

| Treatment Evaluation for Additional TOC Removal at PRF 4-1

Section 4. Treatment Evaluation for Additional TOC Removal at PRF

As previously discussed in Section 3, TOC is an important water quality parameter due to its influence on

chemical demands, clarification, filter performance, disinfection byproduct formation, and disinfectant

residual stability. At the PRF, TOC concentrations could further be reduced through treatment and

potentially strategic withdrawal of supply when source water TOC is lowest, however this approach has

to consider other factors such as supply availability. This section focuses on treatment rather than

strategic withdrawals (which is discussed further in Section 7). Drivers for additional TOC removal,

potential treatment strategies, benefits, and preliminary costs are outlined below.

4.1 Drivers for Additional TOC Removal

Natural organic matter (NOM) in surface water is commonly measured as TOC, which is an aggregate

measure of organic carbon content. TOC originates from different sources such as vegetation, wetlands,

algae, stormwater runoff, and wildlife. When a water supply is disinfected with chlorine or other

disinfectants, these organic compounds can react to form disinfection byproducts (DBPs). The formation

of DBPs is primarily a function of the type and dose of the disinfectant, TOC concentration, reaction time,

and temperature. Free chlorine is one of the most commonly used disinfectants and is responsible for the

formation of the regulated trihalomethanes (THMs) and haloacetic acids (HAAs).

As a result, one technique to reduce THMs and HAAs in water systems is to reduce the source water TOC

through treatment prior to chlorination. In some cases, additional benefits from reduced TOC can include

reduced chemical demands, and improved clarification and filter performance.

In addition to DBP formation and conventional treatment process performance, TOC can also impact the

stability of disinfectant residuals and increase the likelihood of nitrification events. To comply with both

DBP regulations and to maintain required disinfectant residuals, distribution systems often implement

flushing programs. Flushing programs help improve disinfectant residual concentrations by managing the

water age within distribution system, however, they can sometimes lead to significant water loss for

utilities. Within the Authority, water loss from flushing programs vary by Customer and range from 0.2%

to 19% of production as shown on Table 4-1.

Table 4-1: Summary of Customer Flushing Data

Agency Data Date Range

Average Flushed

Volume per Day

(kgal/day)

Average Flushed

Volume per Day

(% of Production)

Notes

Charlotte County 10/2015 – 12/2018 1,004 9.5%

Monthly data; hydrant

flushing; does not include

construction flushing and

unaccounted for water

DeSoto County 1/2017 – 8/2018 148 19%

Daily, breaks/fire/theft,

DJJ autoflusher, Holiday

Inn, Intercon flusher, and

snow flusher flushing

Englewood Information not received



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Agency Data Date Range

Average Flushed

Volume per Day

(kgal/day)

Average Flushed

Volume per Day

(% of Production)

Notes

Manatee County 1/2016 – 11/2018 546 1.4%

Distribution, Water

Treatment Plant Quality

Control Lab, storage

tank, and fire flushing

City of North Port 1/2016 – 12/2017 217 7.6% Dead end and auto

flushing

Punta Gorda 1/2017 – 12/2018 4.13 0.2% Annual data; total

flushing flow

Sarasota County 1/2018 – 10/2018 855 4.4%

Monthly routine

maintenance, hydrant,

Division of Forestry,

customer service

response, north

autoflusher, and south

autoflusher flushing

Due to the current Authority system TOC level, chloramines are utilized as the secondary disinfectant.

Although not as strong of an oxidant as free chlorine, chloramines typically exhibit more stable residuals

and lower DBP formation within long distribution systems. The major drawback to chloramine

disinfection is the increased need for flushing due to residual decay, which can occur in conjunction with

nitrification events.

Given the increasing need to conserve water, managing water loss within potable water systems has

become increasingly important in recent years. Minimizing water loss while maintaining safe levels of

disinfectant residual within distribution systems can be addressed by reducing the amount of organic

matter available to react with a disinfectant. Additional TOC removal at the treatment plant can reduce

potential nitrification events, stabilize disinfectant residuals, and possibly allow for conversion to free

chlorine within the distribution systems in the future.

4.2 Preliminary Treatment Assumptions

Several assumptions were made which were appropriate for the level of detail and certainty required to

develop planning level cost estimates for TOC treatment technologies. Major simplifying assumptions

included the following:

1. Raw Water TOC Concentration: Based on historical data, the average raw reservoir TOC

was found to be 11.8 mg/L. While it is known that this TOC will vary throughout the year, it

was appropriate to base the analysis around the average TOC since the target finished water

TOC was an annual average target. Future work could explore the impact of the variation in

raw TOC on the instantaneous TOC levels in the finished water.

2. Raw Water TOC Characteristics: It was assumed that the raw reservoir TOC was of similar

character throughout the year. While it is suspected that this character is somewhat variable,

the samples taken during this study did not show variation in character as measured by

fluorescence spectroscopy. Future work should confirm the variability of TOC character



Final Report


through other analytical techniques and assess if any measured seasonal variability impacts the

treatability or the specific DBP formation potential of the TOC.

3. Existing Plant Performance: It was assumed that the existing treatment plant performance of

approximately 75% removal of TOC is already optimized and could not be further improved.

However, future work should assess the feasibility of both operational changes and treatment

enhancements that could further increase treatment performance of the existing facility. DBP

levels are monitored through locational running annual average values which are typically

sampled in a quarterly basis. Thus, it was assumed that DBP regulations are met when an

appropriate finished water TOC target is maintained on average throughout the year. As a

result, designs were based on annual average daily flow (AADF) for the plant with the

knowledge that low and peak flow conditions would occasionally affect TOC values and

subsequent DBP formation but not enough to lead to non-compliance. During low flow

conditions, more water was assumed to be treated through the TOC removal technology

resulting in lower finished TOC values and subsequent DBP formation. Conversely, peak flow

conditions were assumed to require a larger bypass flow around the TOC removal technology

leading to higher TOC values and subsequent increased instantaneous DBP formation.

4. Future Blend with Brackish Groundwater Reverse Osmosis (RO) Plant: It was also

assumed that the Authority would implement a brackish groundwater RO treatment plant that

would partially reduce the TOC of the regional water through blending with finished water

from PRF. RO treatment of brackish groundwater would result in a permeate with low TOC

concentrations (assumed to be 0.75 mg/L) with a targeted finished average annual water

production rate of 5.0 MGD. Therefore, it was assumed the RO plant was in operation which

reduced the treatment performance requirements for TOC removal at the PRF.

5. Existing and Future Plant Capacity: Two flow assumptions (existing and future) were

investigated for this study. Because average flows were also used as part of the capital and

operations and maintenance (O&M) cost estimates, analysis of historical flow data was used

to determine the existing average demand. Since future average demand was unknown, a

demand/capacity ratio was utilized to estimate the future annual average demand based on

projected future capacity:

o Existing Capacity

▪ Maximum flow: 51 MGD

▪ Average flow: 30 MGD

o Future Capacity

▪ Maximum flow: 77 MGD

▪ Average flow: 45 MGD (estimated using current demand/capacity ratio)



Final Report


4.3 TOC Target

In order to estimate the cost of the TOC treatment technology alternatives, a target finished water TOC

concentration was required. DBP formation potential (DBPFP) data collected during this study were used

to establish a treated TOC target level based on the criteria of possibility converting from chloramines to

free chlorine in the future. DBPFP testing is a very conservative measure of DBP formation that is used to

predict the maximum concentration of DBPs that could form with extended contact time and free

chlorine. This test is typically conducted by holding chlorinated samples for 7 days at 25 °C with a free

chlorine residual target of 3-5 mg/L remaining at the end of the test. To account for variability, the THM

formation potential (THMFP) and the HAA formation potential (HAAFP) were determined using five

samples taken throughout the year. Table 4-2 summarizes the results of these sampling events.

Table 4-2: Sampling Results Summary

Sample ID Sample Date TOC (mg/L) TTHMFP

(ppb) HAAFP (ppb)

1 March 11, 2019 4.06 185 119.0

2 May 29, 2019 2.68 125 78.0

3 June 20, 2019 2.66 109 77.2

4 August 5, 2019 2.89 128 77.7

5 August 20, 2019 3.28 154 122.0

From the DBPFP results, specific THMFP and specific HAAFP of the existing finished water supply

were calculated using Equation 1. The results of these calculations are shown in Table 4-3.

𝑆𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝐷𝐵𝑃𝐹𝑃 (𝑝𝑝𝑏 𝐷𝐵𝑃

𝑚𝑔

𝐿𝑇𝑂𝐶

) =𝐷𝐵𝑃 𝐹𝑃 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 (𝑝𝑝𝑏)

𝑇𝑂𝐶 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 (𝑚𝑔

𝐿)

Equation 1

Table 4-3: Specific DBP Analysis Results

Sample ID Specific THMFP

(ppb THM / mg/L TOC)

Specific HAAFP

(ppb HAA / mg/L TOC)

1 45.3 29.3

2 46.6 29.1

3 41.0 29.0

4 44.3 26.9

5 47.0 37.2

Average 44.8 30.3

To address seasonal variations in water quality and thus obtain a more representative value, the five

calculated specific THMFP and HAAFP values were averaged. The averaged specific THMFP and

specific HAAFP values were calculated to be 44.8 ppb / mg/L and 30.3 ppb / mg/L, respectively.

The current treatment process reduces the TOC content of the water to approximately 3.0 mg/L, which

produces DBPFP concentrations above the MCL when free chlorine disinfection is utilized. Based on the

calculated specific DBPFP values, 80 ppb of THMs and 60 ppb of HAA are projected to be formed when

TOC levels are at 1.79 mg/L and 1.98 mg/L, respectively. To meet the Stage 2 DBP Rule MCLs, a TOC



Final Report


target of 1.5 mg/L was identified as the associated projected DBPFP concentration that would be at least

15% under the MCL. Thus, the subsequent conceptual designs and cost estimates target a finished water

TOC of 1.5 mg/L. Figure 4-1 visually presents the projected DBP concentration at various TOC levels

based on the calculated average specific DBPFP values.

Figure 4-1: Specific DBP Formation Potential Analysis

4.4 Options for Additional TOC Removal

There are several treatment options available for additional TOC removal including, anion exchange (IX),

magnetic ion exchange (MIEX), granular activated carbon (GAC), ozone-biofiltration, reverse osmosis,

and nanofiltration. While this evaluation was not exhaustive, preliminary screening of the technologies

was focused on identifying processes most likely to be viable options for the PRF without performing a

detailed evaluation of treatment options. The treatment options conceptually evaluated in this study

included:

• Post-filtration GAC contactors since adsorptive treatment for TOC removal is typically

highly effective, and operation can be tuned to a specific target TOC concentration by

varying the fraction of flow which bypasses the GAC.

• Ozonation followed by biological activated carbon (O3-BAC) filtration since it potentially

offers a means to reduce TOC to a target concentration with lower lifecycle cost compared

to GAC.

0

20

40

60

80

100

120

0.00 0.50 1.00 1.50 2.00 2.50 3.00Pro

jecte

d D

BP

FP

Co

nce

ntr

atio

n u

nd

er

fre

e c

hlo

rin

e (

pp

b)

Finished Water TOC (mg/L)

Projected TTHM (ug/L) Projected HAA (ug/L)

HAA MCL TTHM MCL

TTHM MCL

HAA MCL



Final Report


• MIEX pretreatment which utilizes selective resin to target the removal of small molecular

weight organics and typically enhances overall TOC removal when paired with

coagulation which mostly targets the removal of large molecular weight organics.

Typical TOC removal efficiencies for GAC, O3-BAC, and MIEX systems are roughly 90%, 30%, and

60%, respectively. Note that higher and lower removals have been observed depending on the nature of

the TOC and the system design. For this desktop evaluation the GAC and O3-BAC removal efficiencies

utilized were 70% and 30 %. The lower than typical GAC removal efficiency utilized was a conservative

assumption to account for the actual efficiency of a GAC system with contactor beds at various states of

exhaustion.

Reverse osmosis or nanofiltration were not included since the technologies are costly and operationally

challenging with elevated levels of silica and barium, which can both contribute to scaling. Disposal of

concentrate may also impact overall production capacity and can itself be costly. Conventional anion

exchange was also excluded since it would require pressure vessels and potentially additional pumping,

which would be costly to implement given the production capacity of the PRF when compared to MIEX.

4.4.1 Granular Activated Carbon Treatment at the PRF

4.4.1.1 Description

GAC is a unit operation that removes TOC from water by transferring organic compounds from the liquid

stream to the surface of a solid media through intermolecular forces, i.e. adsorption. GAC systems can be

designed using pressure vessels or gravity-fed filter basins. As the name suggest, the media used is

activated carbon, but the carbon can be made from various materials including coal and coconut husks. In

profile view, a GAC system is a column of media that has a mass transfer zone where treatment occurs.

The mass transfer zone’s height is reduced as the media becomes saturated with organic material.

The two main operational points that occur over time are breakthrough and exhaustion, where the former

represents the point at which TOC begins to be measurable in the GAC filtrate and the latter represents

when the filtrate TOC level matches the influent TOC level indicating complete exhaustion of the system.

When a GAC system is exhausted, changeout occurs and the media is either regenerated or replaced.

Generally, GAC systems, like conventional filters, require occasional backwash cycles to maintain proper

flowrate and performance. GAC systems can be operated in parallel trains or in series, depending on

target filtrate quality. The main assumptions utilized to size the GAC system for two flow scenarios were:

• Gravity-fed contactor basins in parallel train configuration

• An average operating TOC removal efficiency of 70%

• 5 MGD concrete contact basins with a 15 min EBCT, a hydraulic loading rate of 4.2

gpm/ft2, a TOC loading rate of 0.2 g TOC/g GAC, and

• A brackish groundwater RO system permeate blend post GAC treatment. The RO system

permeate flow and TOC concentration was assumed to be 5.0 MGD and 0.75 mg/L.

A process flow diagram showing the position of the GAC system in the overall PRF process is shown in

Figure 4-2:.



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Figure 4-2: Process Flow Diagram for GAC Alternative

In terms of operations, the GAC system was assumed to be operated in parallel with staggered change out

frequencies and a bypass stream. The number of basins required was determined based on the required

flow through the GAC system. Table 4-4 summarizes key parameters for the conceptually designed GAC

system. GAC systems are able to achieve and maintain desired finished water TOC levels when operated

properly. In addition to TOC removal, GAC can also remove contaminants of emerging concern, color,

and taste and odor compounds. It is important to note that GAC systems that are not properly operated

and maintained could also lead to an increase in turbidity due to carbon fines that may pass through and

accumulate within the potable water system. These fines can sometimes cause problems within a

distribution system including aesthetic complaints (cloudiness) and increase chances of deposition on pipe

walls that could exacerbate or induce corrosion.

Table 4-4: Proposed GAC Treatment Process Summary

Flow Scenario

Overall Plant

Capacity

(MGD)

Plant

AADF

(MGD)

GAC

Capacity

(MGD)

No. of GAC

Contactors

Average GAC

Bypass

(%)

Predicted Average

Finished Water TOC

(mg/L)

Existing Capacity 51 30 20 4 36% 1.50

Future Capacity 77 45 30 6 34% 1.50

4.4.2 Ozone-Biofiltration at the PRF

4.4.2.1 Description

O3-BAC is a unit process which removes organics from the water stream through advanced oxidation and

subsequent biodegradation. The ozone system serves as a strong oxidant which breaks up long chain

organics into small chain organics which are more readily biodegraded. The activated carbon filter then

serves as the growing medium for bacteria which utilize the assimilable organic carbon as a food source

thereby removing the TOC from the water stream via catabolism. The media for ozone biofiltration can



Final Report


range from activated carbon based to the repurposing of existing conventional multimedia filter beds. For

the purpose of this cost estimate, new post-filter GAC was assumed to be necessary for optimal

biofiltration performance.

With a focus on carbon as the media, operations are based on pressure drop, turbidity, and removal

efficiency. Pressure drop through the media signifies when backwashing must occur, but backwashing

rates must be gentle enough to avoid sloughing off the biological layer that drives the TOC removal.

Turbidity and TOC removal efficiency are important monitoring parameters to determine when media

needs to be replaced due to excessive erosion (media integrity) and when the biological layer is

experiencing difficulties. Like trickling filters, optimum operating condition can be achieved by

maintaining the biofilm layer in the stationary growth phase where the highest TOC removal is observed.

Ozone biofiltration systems are typically operated in parallel mode but can also be operated in series. The

main assumptions utilized to size the O3-BAC system for the two flow scenarios were:

• Gravity-fed contactor basins in parallel train configuration with no bypass stream,

• Average operating TOC removal efficiency of 30%

• An ozone dose of 10-15 mg/L, 5 MGD concrete contact basins with a 15 min EBCT, a

hydraulic loading rate of 4.2 gpm/ft2, a TOC loading rate of 0.4 g TOC/g GAC, and

• A brackish groundwater RO system permeate blend post BAC treatment. The RO system

permeate flow and TOC concentration was assumed to be 5.0 MGD and 0.75 mg/L.

A process flow diagram showing the position of the O3-BAC system in the overall PRF process is shown

in Figure 4-3.

Figure 4-3: Ozone-BAC Process Flow Diagram

The parallel train O3-BAC system was assumed to be have no bypass stream which lead to a larger system

needed than the proposed GAC system. The size of the ozone system and number of BAC basins required

were determined based on the two flow scenarios. Table 4-5 summarizes the key parameters for the

conceptually designed O3-BAC system. The predicted average finished water TOC level achievable by

the O3-BAC system is limited by the typical removal efficiency of the technology (30%). Although there

is a limitation on the TOC removal efficiency that is achievable with this technology, it is important to



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consider that it can also remove taste and odor compounds as well as color at a lower changeout

frequency than GAC. Influent bromide levels must be considered due to the formation of bromate from

the chemical reaction between ozone and bromide. If future consideration is given to using ozone-

biofiltration in conjunction with another treatment technology such as GAC, it may be more cost effective

to use the existing filters for biofiltration.

Table 4-5: Proposed O3-BAC Treatment Process Summary

Flow Scenario

Overall Plant

Capacity

(MGD)

Plant

AADF

(MGD)

O3-BAC

Capacity

(MGD)

No. of BAC

Contactors

Predicted Average

Finished Water

TOC (mg/L)

Current Capacity 51 30 30 6 1.87

Future Capacity 77 45 45 9 1.93

4.4.3 Magnetic Ion Exchange (MIEX) at the PRF

4.4.3.1 Description

MIEX is a strong base anion exchange resin. The resin is typically around 200 micrometers in diameter

and composed of an acrylic skeleton with iron oxide. The resin is magnetized, which causes the individual

resin beads to be attracted to one another. This is important because the treatment process involves

flowing up through a fluidized bed of the resin, but having the resin settle out before the water passes to

the next step in the treatment process. The magnetic attraction allows for a small resin bead size while

maintaining a rapid settling rate necessary for the upflow fluidized bed configuration. MIEX targets low

molecular weight TOC and which in some cases can be complimentary to the TOC targeted by

conventional coagulants thereby improving overall TOC removal during surface water treatment and/or

reducing the required coagulant dose. However, this largely depends on the character of the TOC and

other factors such as sulfate levels which can be a competing ion. The main drawback to MIEX

technology is the generation of a brine waste stream that is normally not able to be recycled to the head of

the plant due to the salinity levels. A process flow diagram showing the anticipated configuration of the

PRF with MIEX at the head of the plant is shown in Figure 4-4.

Figure 4-4: MIEX Process Flow Diagram



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To assess the suitability of MIEX for the PRF, raw water from the PRF surface water plant was sent to a

vendor (IXOM) for testing. Preliminary jar testing results indicate that the MIEX pretreatment system

was optimized at a regeneration rate of 600 bed volumes, which resulted in 61% TOC removal by itself,

with an additional 10% TOC reduction achieved by the simulated existing coagulation treatment,

resulting in an overall TOC removal of 71%. The waste brine stream at 600 BV was estimated to be

33,000 gpd when operating at 51 MGD (i.e. less than 0.1% of the production flow).

The TOC removal results suggested that MIEX treatment was not complementary to alum coagulation for

the PRF. Final blending with the conceptual brackish groundwater RO system permeate yielded a

predicted finished water TOC of approximately 3.5 mg/L. Since the addition of MIEX pretreatment did

not improve overall TOC removal, a cost estimate for the technology was not performed. Although MIEX

pretreatment followed by alum coagulation did not yield favorable results, further MIEX testing

(changing coagulant, changing coagulation pH, etc.) should be conducted with alternate coagulants,

which may yield positive results.

4.5 Estimated Opinion of Probable Construction Costs

The opinion of probable capital and operating costs (EOPCC) were developed for HAC and O3-BAC but

not MIEX due to reasons stated above in 4.4. The EOPCC was based on the Association for the

Advancement of Cost Engineering (AACE) Class V (+50%/-20%) estimates. Using a Class V estimate is

appropriate for screening alternatives and making high-level decisions. In addition, the following cost

assumptions were used:

General Assumptions

• Major capital and O&M costs were obtained from vendors flow (MGD), water quality,

and treatment goals.

• Capital costs associated with system redundancy were not included.

• The costs for interconnecting piping, electrical, and instrumentation and control (I&C)

were estimated as a percentage of equipment capital cost.

• A contingency fee of 35% and an engineering, legal and administrative fee of 25% were

utilized for the conceptual cost calculations.

• Amortization and present worth calculations were based on a 6 percent interest rate and

30-year bond term.

Technology Specific Assumptions

• GAC and BAC capital costs included the equipment, concrete costs (contactor basins),

and initial media load.

• Ozone system capital costs included the LOX system and side stream system in addition

to the ozone generation equipment costs.

• Shelter (open air metal building) and building costs were included to protect the

equipment from the elements on a $/ft2 basis. Treatment options assumed a shelter with

the exception of the ozone equipment, which was assumed to be installed within a

building.



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• The backwash water stream from the GAC & O3-BAC was assumed to be redirected to

the headworks of the plant and thus no sewer disposal fee was included.

• For GAC & O3-BAC, the costs of changeouts was assumed to be a flat fee per 40,000 lbs

of carbon, with the frequency of changeouts varying based on site water quality and

operating mode (GAC vs BAC).

• The O&M costs included for the ozone system incorporated electrical, chemical (liquid

oxygen), and pumping costs.

The general and technology specific cost assumptions were utilized to develop preliminary EOPCCs for

the potential GAC and O3-BAC treatment system alternatives. Table 4-6 and Table 4-7 summarize the

EOPCCs for the GAC and O3-BAC systems, respectively. The tables present the estimated capital, O&M,

amortized, present worth, and per 1000-gallon costs for the two flow scenarios investigated.

Table 4-6: Conceptual GAC System Cost Estimates

Flow

Scenario

Overall

Plant

Capacity

(MGD)

Plant

AADF

(MGD)

GAC

Capacity

(MGD)

Estimated

Capital

Cost

($)

Estimated

O&M

Costs

($/yr)

Estimated

Total

Amortized

Cost

($/yr)

Estimated

Total

Present

Worth

Cost

($)

Estimated

Cost per

1,000

gallons

($/1,000 gal)

Current

Capacity 55 30 20 $ 22.6 M $ 1.3 M $ 3.0 M $40.5 M $ 0.28

Future

Capacity 77 45 30 $ 27.6 M $ 2.0 M $ 4.1 M $55.2 M $ 0.25

Table 4-7: Conceptual O3-BAC System Cost Estimate

Flow

Scenario

Overall

Plant

Capacity

(MGD)

Plant

AADF

(MGD)

O3-BAC

Capacity

(MGD)

Estimated

Capital

Cost

($)

Estimated

O&M

Costs

($/yr)

Estimated

Total

Amortized

Cost

($/yr)

Estimated

Total

Present

Worth

Cost

($)

Estimated

Cost per

1,000

gallons

($/1,000 gal)

Current

Capacity 55 30 30 $ 45.9 M $ 1.0 M $ 4.4 M $59.7 M $ 0.41

Future

Capacity 77 45 45 $ 63.3 M $ 1.6 M $ 6.2 M $85.4 M $ 0.38

4.6 Cost / Benefit Analysis

While there are several potential benefits to operating the regional system at lower TOC concentrations,

including flexibility to operate for extended periods under free chlorine, and improved conventional

treatment process performance; in this report, the cost-benefit analysis was limited to consideration of



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savings due to reduced flushing requirements as consideration of other cost and non-cost benefits would

likely require additional pilot testing and Authority input.

As previously shown in Table 4-1, reported systemwide flushing is a total of 2,775 kgal/day on average.

Assuming an average rate of $3 per thousand gallons, there is a total possible savings of up to $8,300 per

day or approximately $3M per year for the Customers if flushing was completely eliminated. However, it

is reasonable to assume some flushing would still be practiced even at reduced TOC levels due to

distribution system hydraulics, etc. Therefore, the savings could vary between 25% and 75% reduction of

flushing or $0.75M to $2.3M annual savings.

Assuming 50% reduction of flushing (or approximately $1.5M in savings annually) estimated payback

periods were calculated from the present worth of each TOC removal alternatives and are shown below in

Table 4-8:.

Table 4-8: Payback Periods for 50% and 75% Reduction of Flushing

GAC Ozone-BAC

Flow Scenario



75% Flushing

Reduction Payback

Period (yrs)





Existing Capacity 27 18 40 26

Future Flow 37 24 57 37

Based on this analysis, under current cost assumptions and assumptions pertaining to the value of water,

consideration of other benefits would be necessary to justify implementing a TOC removal alternative

(e.g., reduced DBP production, taste and odor, CECs, etc.).



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| Corrosion Control Evaluation 5-1

Section 5. Corrosion Control Evaluation

Corrosion control consists of treatment and/or chemical addition at the treatment facility and/or in the

distribution system to maintain distribution system integrity and maintain finished water quality through

distribution system and customer plumbing. The promulgation of the USEPA Lead and Copper Rule

(LCR) in 1991 established lead and copper concentrations above which additional action is required to

reduce the consumer exposure to these contaminants in drinking water. The Rule established 90th

percentile action levels of 15 μg/L for lead and 1.3 mg/L for copper which, if exceeded required the

implementation of corrosion control techniques. After promulgation in 1991, the Lead and Copper Rule

(LCR) has been supplemented with a series of technical amendments, including more extensive revisions

in January 2000 and October 2007 as well as the recent October 2019 proposal.

The intent of this evaluation is to identify the current practices and performance of the corrosion control

strategies within each Customer’s system and evaluate the benefits of continuing separate strategies

across the region versus implementing a combined regional strategy.

5.1 Drivers for Corrosion Control Evaluation

The primary drivers for this evaluation are the location and magnitude of future demands and the resulting

modification to source contributions, future water quality requirements resulting in treatment changes,

and lead and copper rule revisions. In October 2019, the USEPA published its Long-Term Revisions to

the LCR, the intent of which is to improve the effectiveness of corrosion control and reduce exposure to

lead and copper. As proposed, the rule revisions specify changes to sampling locations which would now

include POCs, schools, and childcare facilities. With sampling required at POCs, the evaluation of

compatibility and blending of different control strategies within the Authority will be important. Future

water needs in the region will lead to different source contributions to each system and may lead to future

water quality requirements that could drive treatment changes at the PRF and at individual Customer

facilities. The proposed LCR Revisions are discussed in detail in Section 2.2.2.11 of the Regulatory

Outlook. Should the proposed language for the rule revisions remain largely unchanged, the impact to the

Authority and its Customers is likely to be significant.

5.2 Current System-Wide Practices

Current corrosion control strategies vary between each Customer and are shown in Figure 5-1



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Figure 5-1: Current Customer Corrosion Control Strategies

5.3 Water Quality Impacts of Current System-Wide Practices

All Customers have consistently met the lead and copper action levels, demonstrating continued corrosion

control success. Sample data for copper and lead are shown in Table 5-1 and Table 5-2 respectively. The

action levels for lead or copper were never exceeded based on the 90th percentile basis. This highlights the

effectiveness of the current corrosion control practices.

Table 5-1: Historical Copper Data

Utility 90th Percentile Dates

Charlotte County 0.12-0.34 2012 & 2014

Desoto County 0.28-.041 2015 & 2017

Englewood 0.25-0.51 2014 & 2017

Manatee County 0.14 2016

North Port 0.21 2017

Punta Gorda 0.08-0.23 1992-2017

Sarasota County 0.29 2017

Authority 0.04-0.06 2014 & 2017

PRMRWSA: Target pH range of 8.1 – 8.2 to achieve neutral/

slightly positive LSI

Manatee: Target pH: 7.0-

8.0 Zinc Metaphosphate

addition

Sarasota: Target pH: 7.3 – 8.0

Orthophosphate addition

Charlotte: No additional

treatment

DeSoto: No additional treatment

North Port: Target pH range of 7.9 – 8.3 to achieve neutral/

slightly positive LSI

Punta Gorda: Target LSI: +-0.2

Polyphosphate addition

Englewood: Target pH of 9.0

to achieve slightly positive LSI



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Table 5-2: Historical Lead Data

Utility 90th Percentile Dates

Charlotte County 0.001-0.003 2012 & 2014

Desoto County 0.0007 2015 & 2017

Englewood 0.005-0.006 2014 & 2017

Manatee County 0.001 2016

North Port 0.003 2017

Punta Gorda 0.001-0.006 1992-2017

Sarasota County 0.002 2017

Authority 0.003-0.004 2014 & 2017

5.3.1 Blending

The Authority is currently updating the Integrated Regional Water Supply Plan. The consultant

conducting that effort performed hydraulic modeling to locate water source mixing zones within the

Authority’s regional system, as well as assessed water age between the Authority and its POCs with

Customers. Figure 5-2 and Figure 5-3 show the estimated water source mixing zones throughout the

regional system for 2020 Annual Average Daily Flow (AADF) and 2040 Maximum Daily Flow (MDF)

respectively. This range of operational conditions shows the projected changes to the water source

mixing zones over time as demands, source waters, and infrastructure change.

It should be noted that the water source mixing zones denoted by the yellow dots in Figure 5-2 and Figure

5-3, reflect mixing of two different water sources at some point in time during the 20-day extended period

simulation that was used during modeling. The mixing does not denote particular percentages of either

water source. Locations where the yellow area is changing in size and location between the 2020 and

2040 projections identify where there is a greater opportunity for different water sources and corrosion

control strategies to interact in the distribution system. This could present challenges in meeting the lead

and copper requirements in the future due to compatibility factors with the mixing of different corrosion

control strategies or changing the corrosion control strategy within an area that is already acclimated to a

different corrosion control strategy.

The hydraulic modeling that was performed is a tool that can be used to identify potential areas of

concern (where the water source mixing zones are shifting/changing in size) to help guide targeted water

quality data gathering to further identify any concerns.

Refer to the Water Age and Interface Modeling Technical Memorandum, July 2019, for further

information on demands, future infrastructure, and system operational assumptions used for the hydraulic

modeling effort.



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Figure 5-2: HDR Hydraulic Model Water Source Blending in 2020



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Figure 5-3: HDR Hydraulic Model Water Source Blending in 2040



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5.3.2 Compatibility

Based on the potential water source interactions observed during the blending evaluation and based on

existing POCs, Table 5-3 and Table 5-4 show the interconnections between Peace River and the

Customers, as well as interconnections between Customers. Based on these interconnections, the potential

concerns and impacts from interactions between the different corrosion control strategies were evaluated

and included the following:

1. Concern – Differing pH regimes that are not optimal for the corrosion control strategies in

use. Different corrosion inhibitor chemical formulations usually have specific optimal pH

ranges. For example, ortho polyphosphates generally perform better in pH ranges of 7.4 to 7.8

SU, which can differ from the optimal range for the proprietary zinc compounds. In addition,

the LSI corrosion control strategy requires a tight pH range to allow for the required scale

build up.

Potential Impact – Blending of two different corrosion inhibitor chemicals or blending of

water with a corrosion inhibitor with a water that is using the LSI corrosion control strategy

may result in suboptimal pH conditions for each of the strategies. The combination of

suboptimal pH could potentially result in decreased control of lead and copper and may cause

exceedances of the respective Action Levels, as well as other corrosion related issues such as

red water (release of iron).

2. Concern – Dilution of the corrosion control chemicals in the water source mixing zones.

Corrosion control chemicals must also be dosed at the appropriate concentrations in order to

be effective.

Potential Impact – Blending of two different corrosion inhibitor chemicals or blending of

water with a corrosion inhibitor with a water that is using the LSI corrosion control strategy

may effectively decrease the concentration of the corrosion inhibitor chemical(s). The

combination of suboptimal concentrations could potentially result in decreased control of lead

and copper and may cause exceedances of the respective Action Levels.

3. Concern – Blending of different corrosion inhibitor chemicals (e.g., mixing zinc

metaphosphate and ortho polyphosphate), which utilize different control mechanisms that act

in opposition. Ortho polyphosphates are polymers containing linked orthophosphate ions in

various structures and are used primarily to sequester metals and work by binding or

coordinating the metals into their structures so they cannot precipitate. Zinc metaphosphates

produce a passivating, microscopic film on metal surfaces that acts as a barrier to

environments that would normally cause corrosion, thus preventing the dissolution of lead and

copper into the water.

Potential Impact – Because the above mechanisms of metal control are very different, it is

likely that blending the two corrosion inhibitor chemicals would decrease the effectiveness of

each and may cause exceedances of the respective Action Levels. The use of an alternative



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corrosion inhibitor chemical in a system that historically used orthophosphate could result in

destabilization of the existing pipe scales causing release of lead and copper into the water, as

well as other corrosion related issues such as red water (release of iron).

Based on current compliance data, the present interconnections do not expose concerns in the current

water source mixing zones where differing corrosion control strategies blend. However, if the LCR

revisions expand sampling to include mixing zones and POCs, some issues could arise in the future.

Areas of future interest are indicated in Table 5-3 and Table 5-4 and are based on the corrosion control

strategies that the Customers currently practice.

Table 5-3: Peace River Interconnections

Utility Control Strategy Interaction Effects

Charlotte County No corrosion control chemicals added Blend only occurs within Charlotte County; no

compatibility issues are expected.

Desoto County No corrosion control chemicals added Blend only occurs within Desoto County; no

compatibility issues are expected, therefore blending is

compatible.

North Port pH target 7.9-8.3 to achieve

neutral/slightly positive Langelier

Stability Index

Strategies are similar to the Authority practices so

blending is likely compatible.

Sarasota pH target: 7.3-8.3

Ortho-polyphosphate addition

Sarasota adds inhibitor after POC but before ground

storage tanks; incompatibility is avoided.

Punta Gorda Target LSI: +-0.2

1.5 mg/L dry polyphosphate addition Blending could decrease the concentration of the

inhibitor used by Punta Gorda which could promote

corrosion; however present compliance data indicates

no issues.



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Table 5-4: Customer Interconnections

Utility 1 Control Strategy 1 Utility 2 Control Strategy 2 Interaction Effects

Punta

Gorda

Target LSI: +-0.2

1.5 mg/L dry

polyphosphate

Charlotte

County

No corrosion control

chemicals added

Concentration of Punta

Gorda distribution inhibitor

would be reduced,

influencing corrosion.

Desoto

County

No corrosion control

chemicals added

Punta Gorda Target LSI: +-0.2

1.5 mg/L dry

polyphosphate

Concentration of Punta

Gorda distribution inhibitor

would be reduced,

influencing corrosion.

Manatee

County

1.8 mg/L zinc

metaphosphate

Sarasota pH target 7.3-8.3

2 mg/L liquid ortho-

polyphosphate

Both utilities use an

inhibitor; the relative

concentration of each

inhibitor would be

decreased, influencing

corrosion; also chemical

interactions between

different inhibitors are

unknown.

Charlotte No corrosion control

chemicals added

North Port pH target 7.9-8.3 to

achieve neutral/slightly

positive Langelier

Stability Index

pH could venture outside

the North Port range,

influencing corrosion

Sarasota pH target 7.3-8.3

2 mg/L liquid

orthophosphate

North Port pH target 7.9-8.3 to

achieve neutral/slightly

positive Langelier

Stability Index

Sarasota’s distribution

inhibitor residual could be

reduced, influencing

corrosion

5.4 Regional Corrosion Control Strategy Discussion

Under the 1991 rule, treatment alternatives listed in the LCR include pH adjustment, adjustment of

calcium carbonate saturation, and the addition of orthophosphate or silicate inhibitors. Of these, the

adjustment of pH and the addition of orthophosphate have proven the most successful. The proposed

revisions would remove calcium hardness as an option for optimizing corrosion control and specifies that

any phosphate inhibitor must be orthophosphate. A regional strategy could be implemented across all

Customers based on two generalized options for a regional strategy, including:

• Alkalinity/pH/dissolved inorganic carbon adjustment to form insoluble scale compounds

which prevent the release of lead and copper (as indicated by a positive Langelier Stability

Index),

• Corrosion inhibitor chemical addition, which generally requires target pH ranges and

concentrations for optimization, so may include pH control chemicals



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An overarching regional strategy would eliminate mixing zone concerns and address potential issues with

corrosion control strategy compatibilities. As shown in Section 5.3.1, mixing zones will become larger

with time and changes in water supply, potentially creating water quality and regulatory compliance

concerns. Additionally, a regional approach could present some shared cost opportunities for chemical

purchases.

However, in order to change the corrosion inhibitor for any reason, the utilities would need to make

capital improvements related to new chemical feed storage and monitoring systems required to practice

the new control strategy. Additionally, they would be required to demonstrate to FDEP the performance

of any new corrosion inhibitor prior to its implementation. To do this, the utility would likely be required

to perform a paper evaluation and some combination of bench testing, coupon testing, or loop testing to

demonstrate no significant adverse impacts to corrosion in the distribution system.

If a new strategy is identified as a suitable candidate and implemented, state and federal rules would

require the utilities to resume the standard level of compliance monitoring, which would increase the

numbers of samples and frequency. Currently, because the current corrosion control strategies have been

effective, all the Customers are on reduced monitoring. The change to a new corrosion control approach

would increase sampling frequency and the number of samples collected in each event, thus increasing

the cost for sampling and analyses until reduced monitoring status can be achieved again. However, the

proposed revisions to the Lead and Copper Rule currently under consideration will change the current

monitoring strategies (locations and frequency) so it would be prudent for the Authority and its

Customers to refrain from making major changes in their respective corrosion control approaches until the

rule is final and its ramifications are clear.

5.5 Recommendations

To summarize the above sub-sections with respect to comparing the two approaches to corrosion control

for the Authority, below lists the advantages and disadvantages for each approach:

Current Corrosion Control Approach:

Advantages:

• Customer control over corrosion approaches allows local optimization

• Regional lead and copper results indicate that the current variety of corrosion control

strategies are successful

• Regional lead and copper results indicate that there are no issues with blending of the

current corrosion control strategies

Disadvantages of maintaining the current corrosion control approach:

• Potential shifting of mixing zones that extend a strategy of one Customer into another

Customer’s distribution system, increasing the potential for corrosion within those zones



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Regional Corrosion Control Approach:

Advantages:

• No mixing zones or areas where different corrosion control strategies meet

• Potential for shared costs for chemical purchases

Disadvantages:

• Capital improvements related to new chemical feed, storage, and monitoring systems

• Evaluations to verify the capability of new strategy

• Increased sampling and regulatory compliance

It is recommended that the Authority and its Customers monitor the status of the proposed Long-Term

Revisions. It would be prudent to establish a regional dialogue focused on the final promulgated

provisions in the near future. A more appropriate time to consider changes in regional corrosion control

strategies would be in conjunction with the rule revision implementation timetable and any associated

changes that may be required as a result of rule implementation.



Final Report

| Regional Water Quality Standards Evaluation 6-1

Section 6. Regional Water Quality Standards Evaluation

Wholesale water suppliers across the country use different approaches for the establishment and

implementation of regional water quality standards. Generally, regional water quality standards are agreed

upon water quality requirements between the wholesale supplier and their customers. The Authority seeks

to explore and understand the various approaches used by other wholesale agencies to document water

quality performance at POC’s with Customers. The current approach used by the Authority and its

Customers is to meet State and Federal SDWA requirements at each POC. The two frameworks

considered in this evaluation are: Action Response Plans and Water Supply Contracts. Action Response

Plans are generally developed to provide guidance and actions for responding to stages of deteriorating

water quality before reaching a regulatory threshold or violation. Water Supply Contracts are contractual

obligations such that the wholesaler agrees to meet specific water quality standards at each POC for each

Customer. The benefits for each framework approach are illustrated by reviewing three example

wholesale water systems: Metropolitan Water District of Southern California, San Francisco Public

Utilities and Tampa Bay Water.

6.1 Examples

Metropolitan Water District of Southern California (MWD) and San Francisco Public Utilities

Commission (SFPUC) are two wholesale suppliers that have implemented Action Response Plans. Action

Response Plans facilitate communication within the wholesale entity as well as between the wholesaler

and its customers. Detail about what is being done from source water to treatment to distribution is

broadly shared which provides the opportunity for discussion and cooperation both within the wholesaler

and with its customers. Monitoring and data sharing are encouraged and facilitated; typically, the plans

include specific locations, frequencies and parameters of interest. In addition, the plans serve as examples

for the customer governments should they want to do their own monitoring. Overall, Action Response

Plans are less prescriptive and more facilitative than the alternative water quality standard framework,

water supply contracts.

6.1.1 Metropolitan Water District of Southern California Action Response Plan

MWD serves 26 public agencies, each of which have their own sub-agencies and customers. In all, over

300 systems are served with raw and/or finished water. Approximately 65% of its production is raw

water. MWD does not commit to specific water quality limits within their Action Response Plan. They

have committed to the development of action response levels to ensure intended operations and water

quality for their member agencies. The Action Plan focuses on the shared development of Action Levels

for water quality parameters and concentration triggers. Online monitoring is used to monitor water

quality but to confirm an Action Plan exceedance grab samples will be taken. MWD defines an Action

Level as a concentration of a substance or water quality parameter that, if exceeded, triggers operational

changes, increased monitoring and sampling, or other actions by staff. Water quality ranging above or

below these goals are categorized as Action Level 1 or Action Level 2. The Action Plan also serves as an

agreed upon documentation of performance. Three responses generally required for any Action Level

exceedance are:



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1. Respond operationally to correct the problem

2. Notify appropriate personnel

3. Document the exceedance in a logbook or retention system.

Table 6-1: Distribution System Total Chlorine Residual Response

Action Level 2 Action Level 1 Normal Range

<0.2 – 0.2 0.2 – 1.8 1.8 – 2.8

Table 6-1 represents the response levels MWD has in place with their customers for the distribution

system Total Chlorine Residual. The following are the responses which MWD has agreed to initiate if

either Action Level is met or exceeded at their POC or in the customer distribution systems. Sites in the

customer distribution systems are identified a priori and routinely monitored in the customer distribution

system by the consecutive system staff.

Total Chlorine Action Level 1: <1.8 mg/L

1. Notify Water Quality Operations Compliance Team (OCT) immediately.

2. Water Quality OCT will increase monitoring frequency as needed.

Total Chlorine Action Level 2: <0.2 mg/L

1. Notify operations control center manager & Water Quality OCT.

2. Collect 250-mL bacteriological samples immediately and every 4 hours thereafter until

residual increases.

3. Increase monitoring frequency as needed.

6.1.2 San Francisco Public Utilities Commission Action Response Plan

San Francisco Public Utilities Commission has an annual average daily flow of 180 MGD, supplies water

to 26 wholesale customers which in turn serve approximately 2.6 million people. In the event water

quality is compromised at a POC or in a customer distribution system, SFPUC initiates its action response

plans. Online monitoring is used to monitor water quality but to confirm an action response plan

exceedance, grab samples will be taken. SFPUC Action Plans typically have three Action Levels, as well

as immediate advisories. The specific trigger levels are unique to each water quality parameter. Table 6-2

lists the responses taken when each threshold is met.



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Table 6-2: SFPUC Water Quality Action Levels for Notification

Response Level Response Action

Level 1 Take Notice; increase vigilance. Initiate internal SFPUC communications for interpreting

unusual data and to prepare for situation escalation.

Level 2 Initiate internal SFPUC communications. If appropriate, notify wholesale customers,

external agencies, and/or issue public notification in the form of a new release.

Level 3 An MCL or regulatory requirement is exceeded, and public notification is mandatory.

Immediate

Advisories

Levels for immediate advisory notifications based on event durations are provided for

parameters with special customer interest.

6.1.3 Tampa Bay Water Supply Contract

Tampa Bay Water is responsible for supplying water to six Member Governments and has a Board of

Directors which acts as the governing board for the Authority. Tampa Bay Water has a water supply

contract with its member governments that stipulates contractual obligations to meet agreed upon water

quality standards at each point of connection for each member government. There are 25 water quality

parameters in the Exhibit D of the water supply contract; compliance is calculated using a 12-month

running annual average of grab samples at a POC. Monthly reports are provided to each government for

each POC. In addition to supplying water that meets these contractual quality expectations, the water

supply contract obligates Tampa Bay Water to provide all the water needed at each point of connection

for each Member Government. In the event of Exhibit D water quality standards not met, Member

Governments will ask Tampa Bay Water to develop a plan on how Tampa Bay Water will fix the

compliance issue. Ultimately, the Board of Directors will make the decision on the action to be taken.

The Water Supply Contract requires that all the Member Governments have to agree to the decision.

Table 6-3: Tampa Bay Water – Exhibit D Water Quality Parameters

Parameter Standards

pH >= 7.0

Conductivity < 850 umhos/cm

Temperature <35 oC

Total Sulfide < 0.1 mg/l as H2S

Alkalinity >100 mg/l as CaCO3

Total Hardness <300 mg/l as CaCO3

Calcium Hardness 50 < x < 250 mg/l CaCO3

Turbidity < 1 NTU

Color < 15 p.c.u.

Ammonia < 1 mg/l as N

Nitrate < 10 mg/l as N

Nitrite < 1 mg/l as N

Fluoride <= 0.8 mg/l as F

Ortho P < 1.0 mg/l as P



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Parameter Standards

TDS < 500 mg/l as TDS

Total Organic Carbon <= 4.6 mg/l as TOC

Iron <= 0.3 mg/l as Fe

6.2 Authority Implications

Table 6-4 summarizes the details of the two approaches: the Action Response Plan and the Water Supply

Contract. The Action Response Plan approach generally has a lower initial cost, while the Water Supply

Contract tends to have higher costs because of the treatment required to meet particular water quality

guarantees. It may be in the interest of the Authority to consider a hybrid action response plan, which

would capture the communication benefits of the action response plan approach, while managing initial

treatment cost requirements of the Water Supply Contract option. The final determination of the regional

water quality standard approach should be based on further discussion between the Authority and its

Customers.

Table 6-4: Water quality standards approach comparison

Regional Water Quality

Standard Approach Detail


• Less prescriptive

• Low initial investment

• Creates communication

avenues

• No compensation for water

quality standards not met

• High personnel cost per event


• Guaranteed water quality

• Cost shared between

members

• Likely to increase cost

because of additional

treatment needed to meet

guaranteed performance

requirements

• Doesn’t facilitate

communication

Considerations for the Authority, before the implementation of a regional water quality standard

approach, are to identify water quality parameters to prioritize at interconnects and engage in enhanced

monitoring at the POCs. Table 6-5 displays the suggested water quality data and collection frequency for

the Authority at POC’s.



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| 6-5

Table 6-5: Suggested water quality data at POCs

Parameter On-line Grab Sample

Chloramine/Free

Ammonia Residual ✓

Nitrite Weekly

Nitrate Weekly

pH ✓

Alkalinity Weekly

TOC Weekly

DBPs Weekly

Color Weekly

Hardness (T and Ca) Weekly

Turbidity ✓

Pb/Cu Weekly

Conductivity/TDS ✓



Final Report

| Conclusions and Next Steps 7-1

Section 7. Conclusions and Next Steps

The WQMP demonstrates the Authority’s commitment to providing consistent, high-quality drinking

water to its Customers, and the importance of water quality as a critical component of water supply

planning. The following are the main conclusions from the WQMP:

• Finished water produced at the PRF and delivered at POCs meets all existing required

State and Federal water quality regulations.

• Additional water quality monitoring will be beneficial in anticipation of future water

quality regulations. Specific water quality parameters of interest to the Authority may

include algal toxins, strontium, nitrosamines, manganese, CECs, PFAS, lead, and copper.

• The reservoir system supports the Authority’s achievement of water quality-based goals

by dampening water quality variability observed in the river, thus enabling the delivery of

consistent influent water quality to the PRF, which benefits treatment and finished water

quality.

• The PRF achieves excellent removal of TOC, with coagulation, flocculation, and

sedimentation serving as the most substantial treatment barrier. At this time, there is no

immediate driver that requires additional TOC reductions; however, the Authority may be

motivated to further reduce TOC in finished water in response to regulatory changes

and/or operational considerations (e.g., to improve disinfectant residual stability; to

minimize flushing requirements; to reduce the risk of taste and odor events).

• The Authority and its Customers are meeting the current Lead and Copper Rule

requirements. The mixing zones between unique corrosion control strategies are expected

to increase under future conditions and should be actively monitored.

• A hybrid action response plan for regional water quality standards would be beneficial to

the Authority and its Customers.

Additionally, the following next steps are recommended for the Authority and its Customers to prepare

for potential regulatory, technological, and/or operational changes in the future:

• Implement additional water quality sampling to prepare for potential future water quality

regulations (Table 7-1).

• Explore the continued use of a business intelligence tool, such as Power BI, to assist with

data tracking and evaluation for the Authority and its Customers.

• Continue to monitor Long-term Revisions to the Lead and Copper Rule and associated

impacts. This includes performing additional water quality monitoring at POCs and at the

distribution system interfaces between Customers with dissimilar corrosion control

strategies and identifying if adjustments to the corrosion control processes are necessary.

• Monitor potential drivers for increased TOC removal and continue to explore TOC

removal options.

• Evaluate benefits of optimizing the schedule of withdrawals from the Peace River to

potentially reduce TOC loading to the reservoir system and the PRF. This may include

increased sampling from Peace River throughout the year to evaluate DBPFPs and

residual impacts. The results of these tests would enable the Authority to quantify the



Final Report


extent to which TOC treatability and reactivity changes throughout the year and thus

whether TOC, in combination with flows and conductivity (or other water quality

parameters), should be used to determine preferred withdrawals. The implementation of

water-quality based withdrawals would require additional water quality monitoring of the

chosen parameters and/or the development of correlations between chosen water quality

parameters and water quality targets established to improve the source water quality to be

harvested.

• Consider development of a water quality model to assist with optimization of river water

withdrawals to meet water supply and water quality objectives. The model may leverage

historical and real-time data being collected by the Authority, as well as data and

projections developed by other parties.

• Evaluate potential for additional TOC removal by further optimizing the existing

treatment processes, thus leveraging existing assets before investing in enhancements.

This may include an operational assessment of the PRF to assess potential improvement

opportunities related to finished water quality, operational efficiency, and reservoir

management.

• Continue to explore the potential implementation of an action response plan by engaging

Customers to determine their perceptions of associated benefits and challenges, as well as

each Customer’s water quality limits of interest that are not already required by regulation.

• Integrate the WQMP into future water supply planning efforts.

Table 7-1: Sampling Recommendations to Prepare for Potential Future Regulatory Changes

Constituent Sampling

Location

Sampling

Time Justification

UCMR4 algal

toxins

Source and

finished water

During algae

events

• Algal toxins are subject to potential regulation after UCMR

4 monitoring

• Authority’s source water is subject to algae blooms

• Enables characterization of source water occurrence and

removal capacity

Strontium Source and

finished water

Wet and dry

season

• Strontium has a health reference level of 1.5 mg/L due to

CCL3 regulatory determination

• Authority’s source watershed is impacted by mining and

agricultural operations, which may lead to strontium

contamination

• Enables characterization of source water occurrence and

removal capacity

Perchlorate Source and

finished water

Wet and dry

season

• USEPA is engaged in rulemaking for perchlorate

• Existing state MCLs for perchlorate

• No existing treatment barriers for perchlorate at the PRF

Chlorate Source and

finished water

Wet and dry

season

• Chlorate may form during manufacture, transport, and/or

storage of bulk hypochlorite, which is used at the PRF

• Chlorate has a health reference level of 210 µg/L due to

CCL3 regulatory determination

• Chlorate is likely to be regulated in the future and may be

included in the six-year review of the State 2 DBP Rule

• No existing treatment barriers for chlorate at the PRF

Nitrosamines

Finished water

and distributed

water

DBP sampling

schedule

• Nitrosamines are associated with the use of chloramines,

which are used for secondary disinfection at the PRF



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Constituent Sampling

Location

Sampling

Time Justification

• Enables benchmarking of chloramine occurrence for

communications with the public and regulators

Manganese Source and

finished water Seasonally

• Manganese has been on CCL3 and CCL4

• Existing Canadian health-based drinking water limit for

manganese of 0.12 mg/L and USEPA health advisory level

of 0.05 mg/L

• Uncertain removal capacity at the PRF;

coagulation/sedimentation/filtration is likely to remove

manganese, but dependent on influent speciation

Per- and

polyfluoroalkyl

substances

(PFAS)

Source and

finished water

Wet and dry

season

• Heightened regulatory and public interest in PFAS

• Enables benchmarking of PFAS occurrence for

communications with the public and regulators

• Existing USEPA health advisory level of 70 ng/L for

combined PFOS and PFOA

• Ongoing state and USEPA activity related to rulemaking



Final Report

| Appendix A: Peace River Facility Hazard Analysis and Critical Control Point Matrix A-1

Appendix A: Peace River Facility Hazard Analysis and Critical Control Point Matrix

Existing treatment processes at the Peace River Facility were characterized in terms of their ability to

serve as barriers against constituents with existing and/or potential future finished water regulations

and guidelines. The Hazen Analysus and Critial Control point (HACCP) matrix that was developed

for the Peace River Facility can be found in the Appendix A file, entitled “Finished Water Quality

Target and Treatment Barrier Summary”.



Final Report

| Appendix B: Authority and Customer Data Request B-1

Appendix B: Authority and Customer Data Request

The following data requests were delivered via email to Authority and Customer staff.



Final Report




Final Report

| Appendix C: Water Quality Baseline (Power BI file) C-1

Appendix C: Water Quality Baseline (Power BI file)

Historical data from the Authority and its Customers were organized and analyzed using Power BI, as

discussed in Section 3. The Water Quality Baseline Dashboards and compiled data that were

developed for the Authority and each individual Customer were provided to the Authority in

electronic format to be opened and reviewed using Power BI. The use of the Power BI dashboards are

briefly described below.

In the righthand area of the dashboard, the user may select one water quantity parameter (i.e., a “flow

type”) at a time from a dropdown list. Historical data for the selected flow type are presented in the

righthand graph, as well as replicated in the left-hand graphs to provide context for water quality data.

Water quantity parameter options in the dropdown list include historical flow information for the

river; transfers between the river, reservoirs, aquifer storage and recovery, and the PRF; and flows

leaving the PRF. Users may also select cumulative water quantity information, such as that pertaining

to water availability in the reservoirs. In Figure C-1, the selected flow type is river flow in units of

cubic feet per second (CFS), thus resulting in the presentation of river flows over time (2016 to 2018),

which show substantial variability throughout the year.

In the left-hand area of the dashboard, the user may compare a given water quality parameter across

sample sites (upper left-hand graph) or compare multiple water quality parameters at a single sample

site (lower left-hand graph). Sample site options include raw river water, raw reservoir (pond) water,

water withdrawn from aquifer storage, settled and finished water at the Peace River Facility, and

distributed water at two points of connection. In the upper left-hand corner of Figure C-1, the user is

viewing historical total dissolved solids (TDS) concentrations in raw river water over time, as

compared with TDS concentrations in raw reservoir water. In the lower left-hand corner of Figure C-

1, the user is viewing TDS and Color concentrations in raw reservoir water.

Additional dashboards were also developed for each individual Customer, an example of which is

shown in Figure C-2. Similar to the Authority Water Quality Baseline Dashboard, each Customer

dashboard allows the user to view various types of flow information over time on the righthand side

of the dashboard, and view water quality information at various sample sites on the left-hand side of

the dashboard.

Please Note: Power BI files/data that are provided with this appendix are static; the

information/trends in PowerBI can be viewed, but the data query cannot be added to or edited due to

the nature of how it was compiled.



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Figure C-1: Peace River Manasota Regional Water Supply Authority Water Quality Baseline Dashboard in Power BI



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Figure C-2: Example of Customer Water Quality Baseline Dashboard in Power BI



Final Report

| Appendix D: Sampling Plan Protocol for the Water Quality Master Plan D-1

Appendix D: Sampling Plan Protocol for the Water Quality Master Plan

peace river manasota regional water supply ......authority’s reservoir system for maintaining raw...

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