Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 1 of 43
National Pollutant Discharge Elimination System (NPDES) Permit Program
FACT SHEET
Regarding an NPDES Permit To Discharge to Waters of the State of Ohio
For Coshocton Wastewater Treatment Plant
Public Notice No.: 17-12-037 Ohio EPA Permit No.: 0PD00004*LD
Public Notice Date: December 22, 2017 Application No.: OH0024775
Comment Period Ends: January 22, 2018
Name and Address of Facility Where
Name and Address of Applicant: Discharge Occurs:
City of Coshocton Coshocton Wastewater Treatment Plant
760 Chestnut Street 2742 County Road 271
Coshocton, Ohio 43812 Coshocton, Ohio
Coshocton County
Receiving Water: Muskingum River
Subsequent Stream Network: Ohio River
INTRODUCTION
Development of a Fact Sheet for NPDES permits is mandated by Title 40 of the Code of Federal Regulations
(CFR), Section 124.8 and 124.56. This document fulfills the requirements established in those regulations by
providing the information necessary to inform the public of actions proposed by the Ohio Environmental
Protection Agency (Ohio EPA), as well as the methods by which the public can participate in the process of
finalizing those actions.
This Fact Sheet is prepared in order to document the technical basis and risk management decisions that are
considered in the determination of water quality based NPDES Permit effluent limitations. The technical basis
for the Fact Sheet may consist of evaluations of promulgated effluent guidelines, existing effluent quality,
instream biological, chemical and physical conditions, and the relative risk of alternative effluent limitations.
This Fact Sheet details the discretionary decision-making process empowered to the Director by the Clean
Water Act (CWA) and Ohio Water Pollution Control Law (Ohio Revised Code [ORC] 6111). Decisions to
award variances to Water Quality Standards (WQS) or promulgated effluent guidelines for economic or
technological reasons will also be justified in the Fact Sheet where necessary.
No antidegradation review was necessary.
Effluent limits based on available treatment technologies are required by Section 301(b) of the CWA. Many of
these have already been established by the United States Environmental Protection Agency (U.S. EPA) in the
effluent guideline regulations (a.k.a. categorical regulations) for industry categories in 40 CFR Parts 405-499.
Technology-based regulations for publicly-owned treatment works are listed in the Secondary Treatment
Regulations (40 CFR Part 133). If regulations have not been established for a category of dischargers, the
director may establish technology-based limits based on best professional judgment (BPJ).
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 2 of 43
Ohio EPA reviews the need for water-quality-based limits on a pollutant-by-pollutant basis. Wasteload
allocations (WLAs) are used to develop these limits based on the pollutants that have been detected in the
discharge, and the receiving water’s assimilative capacity. The assimilative capacity depends on the flow in the
water receiving the discharge, and the concentration of the pollutant upstream. The greater the upstream flow,
and the lower the upstream concentration, the greater the assimilative capacity is. Assimilative capacity may
represent dilution (as in allocations for metals), or it may also incorporate the break-down of pollutants in the
receiving water (as in allocations for oxygen-demanding materials).
The need for water-quality-based limits is determined by comparing the WLA for a pollutant to a measure of the
effluent quality. The measure of effluent quality is called Projected Effluent Quality (PEQ). This is a statistical
measure of the average and maximum effluent values for a pollutant. As with any statistical method, the more
data that exists for a given pollutant, the more likely that PEQ will match the actual observed data. If there is a
small data set for a given pollutant, the highest measured value is multiplied by a statistical factor to obtain a
PEQ; for example, if only one sample exists, the factor is 6.2, for two samples - 3.8, for three samples - 3.0. The
factors continue to decline as samples sizes increase. These factors are intended to account for effluent
variability, but if the pollutant concentrations are fairly constant, these factors may make PEQ appear larger than
it would be shown to be if more sample results existed.
SUMMARY OF PERMIT CONDITIONS
The effluent limits and monitoring requirements proposed for the following parameters are the same as in the
previous permit, although some monitoring frequencies have changed: flow, temperature, dissolved oxygen,
total suspended solids, oil and grease, ammonia, nitrite plus nitrate, total phosphorus, free cyanide, nickel, silver,
zinc, cadmium, lead, chromium, copper, dissolved hexavalent chromium, E. coli, total residual chlorine, total
low level mercury, acute toxicity, pH, total filterable residue, and CBOD.
New monitoring is proposed for dissolved orthophosphate. This monitoring is required by Ohio Senate Bill 1,
which was signed by the Governor on April 2, 2015. Monitoring for orthophosphate is proposed for further
develop nutrient datasets for dissolved reactive phosphorus and to assist stream and watershed assessments and
studies.
New monitoring requirements are proposed for arsenic and selenium at outfall 001 and 601. Additional data is
needed to evaluate its status in the Coshocton effluent.
Annual acute toxicity monitoring is proposed for the life of the permit. This satisfies the minimum testing
requirements of Ohio Administrative Code (OAC) 3754-33-07(B)(11) and will adequately characterize toxicity
in the plant’s effluent.
This permit no longer authorizes the use of method 4500 CN-I from Standard Methods for free cyanide testing.
As soon as possible, the permittee must begin using either ASTM D7237-10 or OIA-1677-09 both of which are
approved methods for free cyanide listed in 40 CFR 136.
To ensure that data is obtained that allows Ohio EPA to make water quality-related decisions regarding,
cadmium, selenium, silver, and lead; a special condition is proposed in Part II of the permit that provides
guidance on the analytical method detection limits (MDLs) the permittee should use in analyzing for these
contaminants.
In Part II of the permit, special conditions are included that address sanitary sewer overflow (SSO) reporting;
operator certification, minimum staffing and operator of record; whole effluent toxicity (WET) testing; storm
water compliance; and outfall signage.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 3 of 43
Table of Contents
Page
Introduction ............................................................................................................................................................. 1
Summary of Permit Conditions ............................................................................................................................... 2
Procedures for Participation in the Formulation of Final Determinations .............................................................. 5
Information Regarding Certain Water Quality Based Effluent Limits ................................................................... 5
Location of Discharge/Receiving Water Use Classification ................................................................................... 7
Facility Description ................................................................................................................................................ 7
Description of Existing Discharge .......................................................................................................................... 8
Assessment of Impact on Receiving Waters ........................................................................................................... 8
Developments of Water-Quality-Based Effluent Limits ......................................................................................... 9
Reasonable Potential/Effluent Limits/Hazard Management Decisions ................................................................ 12
Other Requirements .............................................................................................................................................. 14
List of Figures
Figure 1. Location of Coshocton WWTP .............................................................................................................. 17
Figure 2. Diagram of Wastewater Treatment System ........................................................................................... 18
Figure 3. Sewage Sludge Treatment Diagram ...................................................................................................... 19
Figure 4. Muskingum River Study Area ............................................................................................................... 20
List of Tables
Table 1. Sewage Sludge Removal ......................................................................................................................... 21
Table 2. Effluent Violations for Outfall 001 ....................................................................................................... 211
Table 3. Average Annual Effluent Flow Rates ................................................................................................... 210
Table 4. Sanitary Sewer Overflows Discharges .................................................................................................. 211
Table 5. Effluent Characterization Using Pretreatment Data ................................................................................ 22
Table 6. Effluent Characterization Using Ohio EPA data ..................................................................................... 23
Table 7. Effluent Characterization Using Self-Monitoring Data .......................................................................... 24
Table 8. Projected Effluent Quality for Outfall 001 .............................................................................................. 26
Table 9. Summary of Acute Toxicity Results ....................................................................................................... 28
Table 10. Ohio EPA Toxicity Screening Results for Outfall 001 ......................................................................... 28
Table 11. Use Attainment Table ........................................................................................................................... 29
Table 12. Water Quality Criteria in the Study Area .............................................................................................. 30
Table 13. Instream Conditions and Discharger Flow ............................................................................................ 32
Table 14. Summary of Effluent Limits to Maintain Applicable Water Quality Criteria ....................................... 35
Table 15. Parameter Assessment ........................................................................................................................... 37
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 4 of 43
Table 16. Final Effluent Limits for Outfall 001 .................................................................................................... 39
List of Attachments
Attachment 1. Mercury Data from Pollutant Minimization Program ................................................................... 41
List of Addendums
Addendum 1. Acronyms ...................................................................................................................................... 43
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 5 of 43
PROCEDURES FOR PARTICIPATION IN THE FORMULATION OF FINAL DETERMINATIONS
The draft action shall be issued as a final action unless the Director revises the draft after consideration of the
record of a public meeting or written comments, or upon disapproval by the Administrator of the U.S.
Environmental Protection Agency.
Within thirty days of the date of the Public Notice, any person may request or petition for a public meeting for
presentation of evidence, statements or opinions. The purpose of the public meeting is to obtain additional
evidence. Statements concerning the issues raised by the party requesting the meeting are invited. Evidence
may be presented by the applicant, the state, and other parties, and following presentation of such evidence other
interested persons may present testimony of facts or statements of opinion.
Requests for public meetings shall be in writing and shall state the action of the Director objected to, the
questions to be considered, and the reasons the action is contested. Such requests should be addressed to:
Legal Records Section
Ohio Environmental Protection Agency
P.O. Box 1049
Columbus, Ohio 43216-1049
Interested persons are invited to submit written comments upon the discharge permit. Comments should be
submitted in person or by mail no later than 30 days after the date of this Public Notice. Deliver or mail all
comments to:
Ohio Environmental Protection Agency
Attention: Division of Surface Water
Permits Processing Unit
P.O. Box 1049
Columbus, Ohio 43216-1049
The Ohio EPA permit number and Public Notice numbers should appear on each page of any submitted
comments. All comments received no later than 30 days after the date of the Public Notice will be considered.
Citizens may conduct file reviews regarding specific companies or sites. Appointments are necessary to conduct
file reviews, because requests to review files have increased dramatically in recent years. The first 250 pages
copied are free. For requests to copy more than 250 pages, there is a five-cent charge for each page copied.
Payment is required by check or money order, made payable to Treasurer State of Ohio.
For additional information about this fact sheet or the draft permit, contact Emily Poling, (740) 380 – 5425,
INFORMATION REGARDING CERTAIN WATER QUALITY BASED EFFLUENT LIMITS
This draft permit may contain proposed water-quality-based effluent limits (WQBELs) for parameters that are
not priority pollutants. (See the following link for a list of the priority pollutants:
http://epa.ohio.gov/portals/35/pretreatment/Pretreatment_Program_Priority_Pollutant_Detection_Limits.pdf .)
In accordance with ORC 6111.03(J)(3), the Director established these WQBELs after considering, to the extent
consistent with the Federal Water Pollution Control Act, evidence relating to the technical feasibility and
economic reasonableness of removing the polluting properties from those wastes and to evidence relating to
conditions calculated to result from that action and their relation to benefits to the people of the state and to
accomplishment of the purposes of this chapter. This determination was made based on data and information
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 6 of 43
available at the time the permit was drafted, which included the contents of the timely submitted NPDES permit
renewal application, along with any and all pertinent information available to the Director.
This public notice allows the permittee to provide to the Director for consideration during this public comment
period additional site-specific pertinent and factual information with respect to the technical feasibility and
economic reasonableness for achieving compliance with the proposed final effluent limitations for these
parameters. The permittee shall deliver or mail this information to:
Ohio Environmental Protection Agency
Attention: Division of Surface Water
Permits Processing Unit
P.O. Box 1049
Columbus, Ohio 43216-1049
Should the applicant need additional time to review, obtain or develop site-specific pertinent and factual
information with respect to the technical feasibility and economic reasonableness of achieving compliance with
these limitations, written notification for any additional time shall be sent to the above address no later than 30
days after the Public Notice Date on Page 1.
Should the applicant determine that compliance with the proposed WQBELs for parameters other than the
priority pollutants is technically and/or economically unattainable, the permittee may submit an application for a
variance to the applicable WQS used to develop the proposed effluent limitation in accordance with the terms
and conditions set forth in OAC 3745-33-07(D). The permittee shall submit this application to the above
address no later than 30 days after the Public Notice Date.
Alternately, the applicant may propose the development of site-specific WQS pursuant to OAC 3745-1-39. The
permittee shall submit written notification regarding their intent to develop site specific WQS for parameters
that are not priority pollutants to the above address no later than 30 days after the Public Notice Date.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 7 of 43
LOCATION OF DISCHARGE/RECEIVING WATER USE CLASSIFICATION
The Coshocton WWTP discharges to the Muskingum River at River Mile 108.56, downstream from the
confluence of the Tuscarawas and Walhondling River. Figure 1 shows the approximate location of the facility.
The Muskingum River ultimately flows into the Ohio River.
This segment of the Muskingum River is described by Ohio EPA River Code: 17-001, Hydrologic Unit Code:
05040004-071, County: Coshocton, Ecoregion: West Allegheny Plateau. The Muskingum River is designated
for the following uses under Ohio’s WQS (OAC 3745-1-07): Warmwater Habitat (WWH), Agricultural Water
Supply (AWS), Industrial Water Supply (IWS), and Primary Contact Recreation (PCR).
Use designations define the goals and expectations of a waterbody. These goals are set for aquatic life
protection, recreation use and water supply use, and are defined in the Ohio WQS (OAC 3745-1-07). The use
designations for individual waterbodies are listed in rules -08 through -32 of the Ohio WQS. Once the goals are
set, numeric WQS are developed to protect these uses. Different uses have different water quality criteria.
Use designations for aquatic life protection include habitats for coldwater fish and macroinvertebrates,
warmwater aquatic life and waters with exceptional communities of warmwater organisms. These uses all meet
the goals of the federal CWA. Ohio WQS also include aquatic life use designations for waterbodies which
cannot meet the CWA goals because of human-caused conditions that cannot be remedied without causing
fundamental changes to land use and widespread economic impact. The dredging and clearing of some small
streams to support agricultural or urban drainage is the most common of these conditions. These streams are
given Modified Warmwater or Limited Resource Water designations.
Recreation uses are defined by the depth of the waterbody and the potential for wading or swimming. Uses are
defined for bathing waters, swimming/canoeing (Primary Contact Recreation) and wading only (Secondary
Contact which are generally waters too shallow for swimming or canoeing).
Water supply uses are defined by the actual or potential use of the waterbody. Public Water Supply
designations apply near existing water intakes so that waters are safe to drink with standard treatment. Most
other waters are designated for agricultural water supply and industrial water supply.
FACILITY DESCRIPTION
The Coshocton WWTP was constructed in 1954 and last upgraded in 2016. The average design flow is 4.4
million gallons per day (MGD) and the peak hydraulic capacity is 10.6 MGD. The Coshocton WWTP serves
the City of Coshocton. The Coshocton WWTP has the following treatment processes which are shown on
Figure 2:
• Influent pumping
• Bar screening
• Grit removal
• Scum removal
• Primary sedimentation or clarification (three settling tanks)
• Trickling filter
• Secondary clarification (three final settling tanks)
• Chlorination
• Dechlorination
The City of Coshocton has 100% separated sewers in the collection system.
The City of Coshocton does have an approved pretreatment program. Based on information from their 2017
NPDES renewal application, the City of Coshocton has 8 industrial users including 1 categorical facility and 7
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 8 of 43
significant non-categorical facilities that collectively discharge approximately 0.210 MGD to the Coshocton
WWTP.
The City of Coshocton’s potable water comes from ground water.
The Coshocton WWTP utilizes the following sewage sludge treatment processes (Figure 3):
• Anaerobic Digestion
• Mechanical dewatering-filter press
• Digester gas utilization
Treated sludge is land applied. Table 1 shows the last five years of sludge removed from the Coshocton
WWTP.
The City of Coshocton is covered under the following additional NPDES permit(s): MS4 storm water general
permit 0GQ00013*BG.
DESCRIPTION OF EXISTING DISCHARGE
The Coshocton WWTP had several effluent violations which are shown on Table 2.
The City of Coshocton has an estimated infiltration/inflow (I/I) rate of 1.6 MGD. The average annual effluent
flow rate for the Coshocton WWTP for the previous five years is presented on Table 3
The City of Coshocton reports SSOs at station 300. The number of SSOs and dates recorded is presented on
Table 4.
Under the provisions of 40 CFR 122.21(j), the Director has waived the requirement for submittal of expanded
effluent testing data as part of the NPDES renewal application. Ohio EPA has access to substantially identical
information through the submission of annual pretreatment program reports and/or from Ohio EPA effluent
testing conducted.
Table 5 presents chemical specific data compiled from data reported in annual pretreatment reports.
Table 6 presents chemical specific data compiled from data collected by Ohio EPA.
Table 7 presents a summary of unaltered Discharge Monitoring Report (DMR). Data are presented for the
period of January 2012 to April 2017, and current permit limits are provided for comparison.
Table 8 summarizes the chemical specific data for outfall 001 by presenting the average and maximum PEQ
values.
Table 9 summarizes the results of acute WET tests of the final effluent.
Table 10 summarizes the screening results of Ohio EPA bioassay sampling of the final effluent.
ASSESSMENT OF IMPACT ON RECEIVING WATERS
The Muskingum River watershed assessment unit, which includes the Muskingum River, Tuscarawas River, and
Walhonding River in the vicinity of City of Coshocton, is not listed as impaired on Ohio’s 303(d) list.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 9 of 43
The attainment status of the Muskingum river Watershed is reported as Full Attainment of the WWH use
designation both upstream and downstream of the Coshocton WWTP in the Final Ohio 2016 Integrated Water
Quality Monitoring and Assessment Report. An assessment of the impact of a permitted point source on the
immediate receiving waters includes an evaluation of the available chemical/physical, biological, and habitat
data which have been collected by Ohio EPA pursuant to the Five-Year Basin Approach for Monitoring and
NPDES Reissuance. Other data may be used provided it was collected in accordance with Ohio EPA methods
and protocols as specified by the Ohio WQS and Ohio EPA guidance documents. Other information which may
be evaluated includes, but is not limited to: NPDES permittee self-monitoring data; effluent and mixing zone
bioassays conducted by Ohio EPA, the permittee, or U.S. EPA.
In evaluating this data, Ohio EPA attempts to link environmental stresses and measured pollutant exposure to
the health and diversity of biological communities. Stresses can include pollutant discharges (permitted and
unpermitted), land use effects, and habitat modifications. Indicators of exposure to these stresses include whole
effluent toxicity tests, fish tissue chemical data, and fish health biomarkers (for example, fish blood tests).
Use attainment is a term which describes the degree to which environmental indicators are either above or below
criteria specified by the Ohio WQS (OAC 3745-1). Assessing use attainment status for aquatic life uses
primarily relies on the Ohio EPA biological criteria (OAC 3745-1-07; Table 7-1). These criteria apply to rivers
and streams outside of mixing zones. Numerical biological criteria are based on measuring several
characteristics of the fish and macroinvertebrate communities; these characteristics are combined into
multimetric biological indices including the Index of Biotic Integrity and modified Index of Well-Being, which
indicate the response of the fish community, and the Invertebrate Community Index, which indicates the
response of the macroinvertebrate community. Numerical criteria are broken down by ecoregion, use
designation, and stream or river size. Ohio has five ecoregions defined by common topography, land use,
potential vegetation and soil type.
Three attainment status results are possible at each sampling location -full, partial, or non-attainment. Full
attainment means that all of the applicable indices meet the biocriteria. Partial attainment means that one or
more of the applicable indices fails meet the biocriteria. Nonattainment means that either none of the applicable
indices meet the biocriteria or one of the organism groups indicates poor or very poor performance. An aquatic
life use attainment table (see Table 11) is constructed based on the sampling results and is arranged from
upstream to downstream and includes the sampling locations indicated by river mile, the applicable biological
indices, the use attainment status (i.e., full, partial, or non), the Qualitative Habitat Evaluation Index, and
comments and observations for each sampling location.
DEVELOPMENT OF WATER-QUALITY-BASED EFFLUENT LIMITS
Determining appropriate effluent concentrations is a multiple-step process in which parameters are identified as
likely to be discharged by a facility, evaluated with respect to Ohio water quality criteria, and examined to
determine the likelihood that the existing effluent could violate the calculated limits.
Parameter Selection
Effluent data for the Coshocton WWTP were used to determine what parameters should undergo WLA. The
parameters discharged are identified by the data available to Ohio EPA, DMR data submitted by the permittee,
compliance sampling data collected by Ohio EPA, and any other data submitted by the permittee, such as
priority pollutant scans required by the NPDES application or by pretreatment, or other special conditions in the
NPDES permit. The sources of effluent data used in this evaluation are as follows:
Self-monitoring data (DMR) February 2012 through February 2017
Pretreatment data 2012, 2013, 2014, 2015, 2016
Ohio EPA compliance sampling data 2015
Ohio EPA bioassay sampling data 2015
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 10 of 43
Statistical Outliers and Other Non-representative Data
The data were examined and the following values were removed from the evaluation as non-representative data:
Total filterable residue – 6.34 mg/L on 7/7/15, the reason for this exclusion was the value being 3 orders of
magnitude less than other reported data and a possible error; Mercury – 51.1 ng/L on 4/6/2015, 1.1 ng/L on
6/2/2015, 48.1 ng/L on 6/8/16, 95.2 ng/L on 7/6/16, and 45.9 ng/L on 9/7/16, the reason for these exclusions
were WWTP staff not following proper sample procedures prior to December 2016 and the values in questions
are well outside the range of other detections.
This data is evaluated statistically, and PEQ values are calculated for each pollutant. Average PEQ (PEQavg)
values represent the 95th percentile of monthly average data, and maximum PEQ (PEQmax) values represent the
95th percentile of all data points (see Table 8).
The PEQ values are used according to Ohio rules to compare to applicable WQS and allowable WLA values for
each pollutant evaluated. Initially, PEQ values are compared to the applicable average and maximum WQS. If
both PEQ values are less than 25 percent of the applicable WQS, the pollutant does not have the reasonable
potential to cause or contribute to exceedances of WQS, and no WLA is done for that parameter. If either
PEQavg or PEQmax is greater than 25 percent of the applicable WQS, a WLA is conducted to determine whether
the parameter exhibits reasonable potential and needs to have a limit or if monitoring is required (see Table 12).
Wasteload Allocation
For those parameters that require a WLA, the results are based on the uses assigned to the receiving waterbody
in OAC 3745-1. Dischargers are allocated pollutant loadings/concentrations based on the Ohio WQS (OAC
3745-1). Most pollutants are allocated by a mass-balance method because they do not break down in the
receiving water. For free flowing streams, WLAs using this method are done using the following general
equation: Discharger WLA = (downstream flow x WQS) - (upstream flow x background concentration).
Discharger WLAs are divided by the discharge flow so that the allocations are expressed as concentrations.
The following dischargers to the Muskingum River were considered interactive (see Figure 4):
• WestRock CP Outfalls 002, 003, 004
• Coshocton WWTP
• AK Steel – Coshocton Works
• AEP Conesville Plant
The WestRock CP, Coshocton WWTP, AK Steel – Coshocton Works, and AEP Conesville Plant outfalls were
allocated together for most parameters due to the size of the plant discharges, the flows of the Muskingum
River, and the relatively close proximity of the discharge points. The exception was the wasteload allocations
(WLAs) for ammonia-N toxicity, which were done separately for each facility because ammonia-N is
considered a non-conservative parameter.
The available assimilative capacity was distributed among them using the conservative substance wasteload
allocation (CONSWLA) water quality model for conservative parameters. CONSWLA is the model Ohio EPA
typically uses in multiple discharger situations. CONSWLA model inputs for flow are fixed at their critical low
levels and inputs for effluent flow are fixed at their design or 50th percentile levels. Background concentrations
are fixed at a representative value (generally a 50th percentile). A mass balancing method is then used to
allocate effluent concentrations that maintain WQS under these conditions. This technique is appropriate when
data bases are unavailable to generate statistical distributions for inputs and if the parameters modeled are
conservative.
The applicable waterbody uses for this facility’s discharge and the associated stream design flows are as
follows:
Aquatic life (Warmwater Habitat)
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 11 of 43
Toxics (metals, organics, etc.) Average Annual 7Q10
Maximum Annual 1Q10
Ammonia Average Summer 30Q10
Winter 30Q10
Wildlife Annual 90Q10
Agricultural Water Supply Harmonic mean flow
Human Health (nondrinking) Harmonic mean flow
The applicable waterbody uses for this facility’s discharge to the Ohio River and the associated stream design
flows are as follows:
Aquatic life (Warmwater Habitat)
Toxics (metals, organics, etc.) Average 10% of annual 7Q10
Maximum 1% of annual 1Q10
Agricultural Water Supply 10% of harmonic mean flow
Human Health (carcinogens) 10% of harmonic mean flow
Human Health (non-carcinogens) 100% of 7Q10
Allocations are developed using a percentage of stream design flow as specified in Table 13, and allocations
cannot exceed the Inside Mixing Zone Maximum (IMZM) criteria.
The data used in the WLA are listed in Table 12 and Table 13. The WLA results to maintain all applicable
criteria are presented in Table 14.
Whole Effluent Toxicity Wasteload Allocation
WET is the total toxic effect of an effluent on aquatic life measured directly with a toxicity test. Acute WET
measures short term effects of the effluent while chronic WET measures longer term and potentially more subtle
effects of the effluent.
WQS for WET are expressed in Ohio’s narrative “free from” WQS rule [OAC 3745-1-04(D)]. These “free
froms” are translated into toxicity units (TUs) by the associated WQS Implementation Rule (OAC 3745-2-09).
WLAs can then be calculated using TUs as if they were water quality criteria.
The WLA calculations for WET are similar to those for aquatic life criteria - using the chronic toxicity unit
(TUc) and 7Q10 flow for the average and the acute toxicity unit (TUa) and 1Q10 flow for the maximum. These
values are the levels of effluent toxicity that should not cause instream toxicity during critical low-flow
conditions. For the Coshocton WWTP, the WLA values are 1.0 TUa and 77.91 TUc.
The chronic toxicity unit (TUc) is defined as 100 divided by the estimate of the effluent concentration which
causes a 25% reduction in growth or reproduction of test organisms (IC25):
TUc = 100/IC25
This equation applies outside the mixing zone for warmwater, modified warmwater, exceptional warmwater,
coldwater, and seasonal salmonid use designations except when the following equation is more restrictive
(Ceriodaphnia dubia only):
TUc = 100/geometric mean of No Observed Effect Concentration and Lowest Observed Effect Concentration
The acute toxicity unit (TUa) is defined as 100 divided by the concentration in water having 50% chance of
causing death to aquatic life (LC50) for the most sensitive test species:
TUa = 100/LC50
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 12 of 43
This equation applies outside the mixing zone for warmwater, modified warmwater, exceptional warmwater,
coldwater, and seasonal salmonid use designations.
REASONABLE POTENTIAL/EFFLUENT LIMITS/MANAGEMENT DECISIONS
After appropriate effluent limits are calculated, the reasonable potential of the discharger to violate the WQS
must be determined. Each parameter is examined and placed in a defined "group". Parameters that do not have
a WQS or do not require a WLA based on the initial screening are assigned to either group 1 or 2. For the
allocated parameters, the preliminary effluent limits (PEL) based on the most restrictive average and maximum
WLAs are selected from Table 14. The average PEL (PELavg) is compared to the average PEQ (PEQavg) from
, and the PELmax is compared to the PEQmax. Based on the calculated percentage of the allocated value [(PEQavg
÷ PELavg) X 100, or (PEQmax ÷ PELmax) X 100)], the parameters are assigned to group 3, 4, or 5. The groupings
are listed in Table 15.
The final effluent limits are determined by evaluating the groupings in conjunction with other applicable rules
and regulations. Table 16 presents the final effluent limits and monitoring requirements proposed for the
Coshocton WWTP outfall 001 and the basis for their recommendation. Unless otherwise indicated, the
monitoring frequencies proposed in the permit are continued from the existing permit.
Water Temperature and Flow Rate
Monitoring for these parameters is proposed to continue in order to evaluate the performance of the treatment
plant.
Total Suspended Solids and 5-day Carbonaceous Biochemical Oxygen Demand
The limits proposed for total suspended solids, and 5-day carbonaceous biochemical oxygen demand are all
based on plant design criteria. The limits recommended for total suspended solids, ammonia, and 5-day
carbonaceous biochemical oxygen demand are technology-based treatment standards included in 40 CFR Part
133, Secondary Treatment Regulation. Secondary treatment is defined by the Best Practicable Waste Treatment
Technology criteria, which are minimum standards required of all publicly owned treatment works. These limits
are protective of WQS. For a facility required to meet secondary treatment standards, monitoring of ammonia-N
and dissolved oxygen is appropriate and is proposed.
Dissolved Oxygen and Ammonia
Monitoring for dissolved oxygen and ammonia is proposed to continue in order to evaluate the performance of
the treatment plant.
Oil and Grease, pH, Phosphorus and Escherichia coli
Limits proposed for oil and grease, pH, and Escherichia coli are based on WQS (OAC 3745-1-35 and 37).
Primary contact recreation E. coli standards apply to the Muskingum River.
Total Residual Chlorine
It is proposed that the existing permit limit, which is based on WLA (Table 15), for total residual chlorine be
continued. These limits are protective of WQS.
Low level Mercury
The Ohio EPA risk assessment (Table 15) places mercury in group 5. This placement as well as data in Tables
1, 2, and 5 indicate that the reasonable potential to exceed WQS exists and limits are necessary to protect water
quality.
Mercury Variance
To comply with mercury limits, the Coshocton WWTP has applied for coverage under the individual mercury
variance, OAC 3745-33-07(D)(10). Based on the results of low-level mercury monitoring, the permittee has
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 13 of 43
determined that its facility cannot meet the 30-day average WQBEL of 12 ng/l. The permittee believes that the
plant will not be able to achieve an annual average mercury effluent concentration of 12 ng/L without plant
upgrades. The incomplete variance application did not demonstrate to the satisfaction of Ohio EPA that there is
no readily apparent means of complying with the WQBEL without constructing prohibitively expensive end-of-
pipe controls for mercury. Based on these factors, the permittee is not eligible for coverage under the individual
mercury variance.
Ohio EPA has reviewed the mercury variance application and has determined that it does not meet all the
requirements of the OAC 3745-33-07 (D). The following requirements were not met:
• A requirement that the permittee make reasonable progress to meet the WQBEL for mercury by
implementing the plan of study, which has been developed as part of the Pollutant Minimization
Program (PMP); Influent outfall 601 data submission does not reflect reasonable progress in mercury
reduction implementation for removing mercury from the sewerage system.
• Low level mercury sampling methods were found invalid due to improper sampling techniques. The
requirement to use an approved USEPA analytical method that is capable of quantifying the applicable
water quality standard was not followed.
Ohio EPA has reviewed the mercury variance application and has incorporated the following requirements into
the permit:
- Coshocton WWTP make reasonable progress to meet the water-quality-based effluent limit for mercury by
implementing the plan of study which has been developed as part of the pollutant minimization program; This
PMP shall continue to evaluate sources and implement source control strategies.
- Coshocton WWTP implement the Dental Amalgam Rule 40 CFR 441.
The City may apply for a variance by submitting a completed mercury variance application per 3745-33-
07 (D) of the Ohio Administrative Code. Ohio EPA would then review the completed application, and if
approved, would proceed to modify the permit to incorporate variance-based mercury limits and
conditions associated with the mercury variance. Coshocton WWTP is required to submit a mercury
variance application (if needed) no later than 24 months after the effective date of the permit. If the
Coshocton WWTP does not apply for a mercury variance and the permit is not modified, WQBELs for
mercury will become effective 24 months from the effective date of the permit.
In 2017, Coshocton WWTP began following proper QA/QC sampling techniques for low level mercury at
outfall 001. Prior to 2017, low level mercury sampling data was collected using incorrect sampling
techniques causing outliers to be introduced into mercury data sets used to evaluate WQBEL compliance.
A 24 month compliance schedule is proposed to provide additional monthly mercury data collection and
evaluation to determine compliance with the WQBEL. Collecting and analyzing the samples for mercury
must be performed using U.S. EPA Method 1631 or 245.7.
Nitrate+Nitrite-N, Total Phosphorus
Based on best technical judgment (BTJ), monitoring is proposed to continue for the following nutrient-related
parameters: nitrate-nitrite-N, and total phosphorus. The purpose of the monitoring is to maintain a data set on a
point source nutrient load discharged to the receiving water.
Monitoring for phosphorus and nitrate+nitrite at the upstream and downstream stations is proposed to continue.
The purpose of the monitoring is to maintain a nutrient data set for use in future water quality studies.
Dissolved Orthophosphate
New monthly monitoring is proposed for dissolved orthophosphate (as P). This monitoring is required by Ohio
Senate Bill 1, which was signed by the Governor on April 2, 2015. Monitoring for orthophosphate is proposed
to further develop nutrient datasets for dissolved reactive phosphorus and to assist stream and watershed
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 14 of 43
assessments and studies. Since Ohio EPA monitoring, as well as other in-stream monitoring, is taken via grab
sample, orthophosphate is proposed to be collected by grab sample to maintain consistent date to support
watershed and stream surveys. Monitoring will be done by grab sample, which must be filtered within 15
minutes of collection using a 0.45-micron filter. The filtered sample must be analyzed within 48 hours.
Arsenic, Cadmium, Chloroform, Chromium, Dichloromethane, Molybdenum, Nickel, Selenium, Silver and
Strontium
The Ohio EPA risk assessment (Table 15) places these parameters in group 2. This placement supports that
these parameters do not have the reasonable potential to contribute to WQS exceedances, and limits are not
necessary to protect water quality. Monitoring at low frequency is proposed for arsenic, cadmium, chromium,
nickel, nitrate+nitrite, selenium, and silver to document that these pollutants continue to remain at low levels.
No new monitoring is proposed for chloroform, dichloromethane, molybdenum, and strontium.
Barium, Bis(2-ethylhexyl)phthalate, Hexavalent Chromium, Copper, Free Cyanide, Iron, Lead, Total
filterable Residue, and Zinc.
The Ohio EPA risk assessment (Table 15) places these parameters in group 3. This placement supports that
these parameters do not have the reasonable potential to contribute to WQS exceedances, and limits are not
necessary to protect water quality. Monitoring at low frequency is proposed for copper, lead, and zinc.
Monitoring at a frequency of 1/month is proposed for free cyanide, hexavalent chromium, and total filterable
residue to document that these pollutants continue to remain at low levels. No new monitoring is proposed for
barium, bis(2-ethylhexyl)phthalate, and iron.
Whole Effluent Toxicity Reasonable Potential
Based on evaluating the WET data presented in TTable 8 and other pertinent data under the provisions of OAC
3745-33-07(B), the Coshocton WWTP is placed in Category 4 with respect to WET. While this indicated that
the plant’s effluent does not currently pose a toxicity problem, annual testing is proposed consistent with the
minimum monitoring requirements at OAC 3745-33-07 (B)(11). Annual acute toxicity testing for Ceriodaphnia
dubia and Pimephales promelas is proposed for the duration of the permit. The proposed monitoring will
adequately characterize toxicity in the plant’s effluent.
Additional Monitoring Requirements
New monitoring for arsenic, molybdenum, and selenium is being proposed at the influent monitoring station 601
because Coshocton implements an approved pretreatment program, and these parameters the city must evaluate
as part of the local limit technical justification. Quarterly monitoring is proposed. Monitoring for dissolved
oxygen, total suspended solids, total cyanide, nickel, silver, zinc, cadmium, lead, chromium, copper, hexavalent
chromium, mercury, pH(max. and min.), and cBOD at station 601 is proposed to continue.
Monitoring for temperature, total suspended solids, ammonia, flow rate, pH(max. and min.), and cBOD at
stations 602 is proposed to continue. The purpose of the monitoring is to evaluate the bioethane pretreatment
plant effluent.
Additional monitoring requirements proposed at the final effluent, influent and upstream/downstream stations
are included for all facilities in Ohio and vary according to the type and size of the discharge. In addition to
permit compliance, this data is used to assist in the evaluation of effluent quality and treatment plant
performance and for designing plant improvements and conducting future stream studies.
Sludge
Limits and monitoring requirements proposed for the disposal of sewage sludge by the following management
practices are based on OAC 3745-40: land application, removal to sanitary landfill or transfer to another facility
with an NPDES permit.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 15 of 43
OTHER REQUIREMENTS
Compliance Schedule – Part I, C.
Pretreatment Local Limits Review
A 6 month compliance schedule is proposed for the City to submit a technical justification for either revising its
local industrial user limits or retaining its existing local limits. If revisions to local limits are required, the City
must also submit a pretreatment program modification request. Details are in Part I.C of the permit.
Mercury Variance Evaluation
The permittee may evaluate the need for a mercury variance if determined that proper mercury sampling, data
evaluation, and compliance meet the requirements set forth in 3745-33-07 (D) of the Ohio Administrative Code.
The City shall demonstrate significant progress in identifying and implementing source reduction of mercury at
the WWTP. A 6 month compliance schedule is proposed for the city to demonstrate an effective plan for
implementation of the Dental Amalgam Rule 40 CFR 441. In 2017, the city sampled septic truck wastewater for
low level mercury. These results indicated that hauler sources introduce significant amounts of low level
mercury at the wastewater treatment plant. The city has also continued to sample the collection system to
identify the location of mercury sources for reduction.
Sanitary Sewer Overflow Reporting
Provisions for reporting SSOs are again proposed in this permit. These provisions include: the reporting of the
system-wide number of SSO occurrences on monthly operating reports; telephone notification of Ohio EPA and
the local health department, and 5-day follow up written reports for certain high risk SSOs; and preparation of
an annual report that is submitted to Ohio EPA and made available to the public. Many of these provisions were
already required under the “Noncompliance Notification”, “Records Retention”, and “Facility Operation and
Quality Control” general conditions in Part III of Ohio NPDES permits.
Operator Certification and Operator of Record
Operator certification requirements have been included in Part II of the permit in accordance with rules adopted
in December 2006 (OAC 3745-7-02). These rules require the Coshocton WWTP to have a Class III wastewater
treatment plant operator in charge of the sewage treatment plant operations discharging through outfall 001.
These rules also require the permittee to designate one or more operator of record to oversee the technical
operation of the treatment works and sewerage system.
Low-Level Free Cyanide Testing
Currently there are two approved methods for free cyanide listed in 40 CFR 136.3 that have quantification levels
lower than any water quality-based effluent limits:
- ASTM D7237-10 and OIA-1677-09 - Flow injection followed by gas diffusion amperometry
These methods will allow Ohio EPA to make more reliable water quality-related decisions regarding free
cyanide. Because the quantification levels are lower than any water quality-based effluent limits, it will also be
possible to directly evaluate compliance with free cyanide limits.
New NPDES permits no longer authorize the use of method 4500 CN-I from Standard Methods for free cyanide
testing. The new permits require permittees to begin using one of these approved methods as soon as possible.
If a permittee must use method 4500 CN-I during the transition to an approved method, they are instructed to
report the results on their DMR and enter “Method 4500 CN-I” in the remarks section.
Method Detection Limit
Part II of the permit includes a condition requiring the Coshocton WWTP to use laboratory analytical methods
with an appropriate MDL.
Outfall Signage
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 16 of 43
Part II of the permit includes requirements for the permittee to place and maintain a sign at each outfall to the
Muskingum River providing information about the discharge. Signage at outfalls is required pursuant to OAC
3745-33-08(A).
Storm Water Compliance
To comply with industrial storm water regulations, the permittee submitted a form for "No Exposure
Certification" which was signed on August 23, 2017. The certification number is 0GRN00333*AG. Compliance
with the industrial storm water regulations must be re-affirmed every five years. No later than August 23, 2022,
the permittee must submit a new form for "No Exposure Certification" or make other provisions to comply with
the industrial storm water regulations.
Part III
Part III of the permit details standard conditions that include monitoring, reporting requirements, compliance
responsibilities, and general requirements.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 17 of 43
Figure 1. Location of Coshocton WWTP
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 18 of 43
Figure 2. Diagram of Wastewater Treatment System
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 19 of 43
Figure 3. Sewage Sludge Treatment Diagram
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 20 of 43
Figure 4. Muskingum River Study Area
Direction of Flow
RM = River mile
milemile2.75 WWTP = wastewater treatment plant
Muskingum River
Outfall 001
Intake 801 AEP Conesville
AK Steel- Coshocton RM 105.88
Coshocton WWTP RM 108.56
RM 102.89
003
002
004
WestRock CP
Tuscarawas River Walhonding River
RM 0.40
RM 1.04
RM 1.17
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 21 of 43
Table 1. Sewage Sludge Removal
Year Dry Tons Removed
2012 173.65
2013 178.89
2014 195.02
2015 146.93
2016 273.19
Table 2. Effluent Violations for Outfall 001
Parameter 2012 2013 2014 2015 2016
Chlorine 3 5 21 1 2
Mercury, Low level 0 0 0 1 3
E. coli 0 0 2 2 0
pH (minimum) 0 0 1 0 0
cBOD 0 0 0 1 0
Total 3 5 24 5 5
Table 3. Average Annual Effluent Flow Rates
Year
Annual Flow in MGD
50th
Percentile
95th
Percentile Maximum
2012 1.50 2.20 5.20
2013 1.70 2.90 5.40
2014 1.70 3.30 5.40
2015 1.70 3.10 5.70
2016 1.60 2.40 4.40
MGD = million gallons per day.
Table 4. Sanitary Sewer Overflows Discharges
Year Number
2012 0
2013 3
2014 0
2015 1
2016 4
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 22 of 43
Table 5. Effluent Characterization Using Pretreatment Data
Parameter (µg/l) 7/16/2012 7/9/2013 7/8/2014 6/30/2015 7/12/2016
Antimony AA (6.0) AA (4.0) AA (3.0) AA (3.0) AA (3.0)
Arsenic AA (4.0) AA (4.0) AA (6.0) AA (3.0) AA (3.0)
Beryllium AA (1) AA (1) AA (1) AA (1) AA (1)
Cadmium AA (1) AA (1) AA (1) AA (1) AA (1)
Chromium AA (10) AA (10) AA (10) AA (10) AA (10)
Copper AA (10) 10 AA (10) AA (10) AA (10)
Lead AA (2) AA (2) AA (2) AA (2) AA (2)
Mercury AA (0.2) AA (0.2) AA (0.2) AA (0.2) AA (0.2)
Nickel AA (20) AA (20) AA (20) AA (20) AA (20)
Selenium AA (40) AA (40) AA (40) AA (40) AA (40)
Silver AA (2) AA (2) AA (2) AA (2) AA (2)
Thallium AA (1.5) AA (3.0) AA (1.5) AA (1.5) AA (1.5)
Zinc 67 41 99 53 81
Total Cyanide AA (0.2) 0.021 0.063 0.041 AA (0.02)
Bis(2ethylhexyl)phthalate 5.4 AA (10.0) 6 AA (10.0) AA (5.0)
AA = not-detected (analytical method detection limit)
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 23 of 43
Table 6. Effluent Characterization Using Ohio EPA data from Outfall 001
Parameter Units 11/2-3/2015
Alkalinity mg/l 128
Aluminum µg/l AA (200)
Ammonia mg/l 1.95
Arsenic µg/l 2.2
Barium µg/l 15
Bis(2-ethylhexyl)phthalate µg/l 11.1
Cadmium µg/l AA (0.2)
Calcium mg/l 37.6
Carbonaceous Biochemical
Oxygen Demand (5 day) mg/l 14
Chloride mg/l 228
Chloroform µg/l 0.50
Chloromethane µg/l 0.71
Chromium µg/l AA (2.0)
Conductivity mg/l 1150
Copper µg/l 15.7
Cyanide, Free µg/l 25
Cyanide, Total µg/l AA (10.0)
Hardness, Total mg/l 161
Hexavalent Chromium µg/l 10
Iron µg/l 446
Lead µg/l AA (2.0)
Magnesium mg/l 16.2
Methylene Chloride µg/l 0.50
Nickel µg/l 2.9
Nitrate+Nitrite mg/l 10.4
Oil & Grease mg/l 2.1
Orthophosphate, dissolved mg/l 13.1
Phenolics µg/l 10
Potassium mg/l 16.2
Silver µg/l AA (2.0)
Sodium mg/l 171
Strontium µg/l 116
Total Filterable Residue mg/l 702
Total Kjeldahl Nitrogen mg/l 5.2
Total Suspended Solids mg/l 17
Zinc µg/l 65
AA = not detected (analytical method detection limit)
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 24 of 43
Table 7. Effluent Characterization Using Self-Monitoring Data
Current Permit Limits # Percentiles
Parameter Season Units 30 day Daily Obs. 50th 95th Data Range
Outfall 001
Water Temperature Annual °C - - - - - Monitor - - - - - 1827 15 22 2-25
Dissolved Oxygen Summer mg/l - - - - - Monitor - - - - - 920 5.2 7.2 3.2-18
Dissolved Oxygen Winter mg/l - - - - - Monitor - - - - - 907 7.3 9.7 2.9-11.6
Total Suspended Solids Annual mg/l 30 45a 720 13 29 2-39
kg/day 500 750a -- -- -- --
Oil and Grease Annual mg/l Maximum: 10 124 0.0 5.85 0-9
Total Dissolved Residue Annual mg/l - - - - - Monitor - - - - - 16 565 694 268-722
Ammonia (Summer) Summer mg/l - - - - - Monitor - - - - - 360 1.99 6.71 0.036-17
Ammonia (Winter) Winter mg/l - - - - - Monitor - - - - - 360 4.02 17.8 0.52-36.6
Nitrate + Nitrite Annual mg/l - - - - - Monitor - - - - - 60 8.15 16.4 0-17.2
Phosphorus, Total Annual mg/l - - - - - Monitor - - - - - 60 12.2 21.3 0.872-25.1
Orthophosphate,
Dissolved Annual mg/l - - - - - Monitor - - - - - 1 15.3 15.3 15.3-15.3
Cyanide, Free Annual mg/l - - - - - Monitor - - - - - 60 0 0 0-0
Nickel, TR Annual µg/l - - - - - Monitor - - - - - 20 0 20.3 0-25
Silver, TR Annual µg/l - - - - - Monitor - - - - - 31 0 0 0-0
Zinc, TR Annual µg/l - - - - - Monitor - - - - - 20 58 115 31-126
Cadmium, TR Annual µg/l - - - - - Monitor - - - - - 20 0 0 0-0
Lead, TR Annual µg/l - - - - - Monitor - - - - - 20 0 5.55 0-54
Selenium, TR Annual µg/l - - - - - Monitor - - - - - 16 0 0 0-0
Chromium, TR Annual µg/l - - - - - Monitor - - - - - 20 0 0 0-0
Copper, TR Annual µg/l - - - - - Monitor - - - - - 60 11.5 23.3 0-37
Hexavalent Chromium
(Dissolved) Annual µg/l - - - - - Monitor - - - - - 60 0 0 0-0
E. coli Annual
#/100
ml 126 284a 302 44.5 998 1-6100
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 25 of 43
Current Permit Limits # Percentiles
Parameter Season Units 30 day Daily Obs. 50th 95th Data Range
Flow Rate Annual MGD - - - - - Monitor - - - - - 1827 1.6 2.8 1-5.7
Chlorine, Total Residual Annual mg/l Maximum: 0.038 916 0.02 0.04 0.01-0.83
Mercury, Low level
Annual- Initial
Table ng/l 37 60 13.4 43.2 1.1-95.2
Annual – Final
Table ng/l 12 -- -- -- --
Initial Table kg/day 0.000616 0.028 -- -- -- --
Final Table kg/day 0.0002 0.0284
ng/l Maximum: 1700
Acute Toxicity,
Ceriodaphnia dubia Annual TUa - - - - - Monitor - - - - - 5 0 0 0-0
Acute Toxicity,
Pimephales promelas Annual TUa - - - - - Monitor - - - - - 5 0 0.16 0-0.2
pH, Maximum Annual S.U. Maximum: 9.0 1827 7.5 7.9 6.8-8.6
pH, Minimum Annual S.U. Minimum: 6.0 1827 7.3 7.7 6-7.9
Residue, Total Filterable Annual mg/l - - - - - Monitor - - - - - 44 653 846 6.34-942
Carbonaceous
Biochemical Oxygen
Demand (5 day) Summer mg/l 25 40a 360 9 18 1-33
Initial Table kg/day 417 667a -- -- -- --
Final Table kg/day 416 666a -- -- -- --
Carbonaceous
Biochemical Oxygen
Demand (5 day) - Initial
001 Table Winter mg/l 25 40a 360 13 26.1 1-114
Initial Table kg/day 417 667a -- -- -- --
Final Table kg/day 416 666a -- -- -- -- * = For minimum pH, 5th percentile shown in place of 50th percentile.
** = For dissolved oxygen, 5th percentile shown in place of 95th percentile. a = weekly average.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 26 of 43
Table 8. Projected Effluent Quality for Outfall 001
Number
of Number > PEQ PEQ
Parameter Units Samples MDL Average Maximum
Self-Monitoring (DMR) Data
Ammonia-N (Summer) mg/L 240 240 3.761 7.426
Ammonia-N (Winter) mg/L 204 204 13.03 17.85
Cadmium A μg/L 27 0 -- --
Chlorine, Total Residual mg/L 916 916 0.0294 0.0591
Chromium A μg/L 27 0 -- --
Hexavalent Chromium
(Dissolved) A μg/L 65 1 7.3 10
Copper A μg/L 70 38 21.62 32.34
Cyanide, Free A mg/L 65 1 0.0183 0.025
Lead A μg/L 27 3 47.30 64.8
Mercury ng/L 60 60 20.67 29.44
Nickel A μg/L 27 3 21.9 30
Nitrate + Nitrite A mg/L 65 64 12.53 17.16
Orthophosphate, Dissolved (as
P) A mg/L 6 6 25.91 35.49
Phosphorus A mg/L 65 65 18.32 25.1
Selenium A μg/L 22 0 -- --
Silver A μg/L 38 0 -- --
Total Filterable Residue A mg/L 64 64 773.9 926.2
Zinc A μg/L 27 27 92.63 126.5
Combined Other Data B
Arsenic μg/L 6 1 6.57 9
Barium μg/L 1 1 67.89 93
Bis(2-ethylhexyl)phthalate μg/L 6 3 17.02 23.31
Calcium mg/L 1 1 170.2 233.1
Chlorides mg/L 1 1 1032 1414
Chloroform μg/L 6 2 10.44 14.30
Chloromethane (Methyl
chloride) μg/L 1 1 3.213 4.402
Cyanide, total μg/L 6 6 0.120 0.164
Iron μg/L 1 1 2019 2765
Magnesium mg/L 1 1 73.32 100.4 A = DMR data combined with Ohio EPA and/or Pretreatment Program data B = Combined other data sources include Pretreatment data and Ohio EPA data
DMR = Discharge Monitoring Report
MDL = analytical laboratory method detection limit
PEQ = projected effluent quality
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 27 of 43
Table 8. Projected Effluent Quality for Outfall 001 (continued)
Number
of Number > PEQ PEQ
Parameter Units Samples MDL Average Maximum
Combined Other Data B
Methylene chloride
(Dichloromethane) μg/L 6 1 2.263 3.1
Nitrogen, Total Kjeldahl mg/L 1 1 23.54 32.24
Potassium mg/L 1 1 73.32 100.4
Phenolics μg/L 1 1 45.26 62
Sodium mg/L 1 1 773.9 1060
Strontium μg/L 1 1 525.0 719.2 B = Combined other data sources include Pretreatment data and Ohio EPA data
DMR = Discharge Monitoring Report
MDL = analytical laboratory method detection limit
PEQ = projected effluent quality
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 28 of 43
Table 9. Summary of Acute Toxicity Results
Ceriodaphnia Dubia Pimephales promelas
Date TUa TUa
8/08/2012 AA AA
8/01/2013 AA AA
8/01/2014 AA AA
8/26/2015 AA AA
8/11/2016 AA AA
AA = non-detection; analytical method detection limit of 0.2 TUa
TUa = acute toxicity unit
Table 10. Ohio EPA Toxicity Screening Results for Outfall 001
Pimephales promelas Ceriodaphnia dubia
%M %M
Date 24 hours 48 hours 24 hours 48 hours
11/02/2015 0 0 0 5
11/03/2015 0 0 0 0
11/02/15-11/03/15a 0 0 0 0
a = 24-hour composite sample
%M = percent mortality in 100% effluent
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 29 of 43
Table 11. Use Attainment Table Location Year(s) River
Mile
AL Use
Designation
Attainment
Status
Causes of
Impairment
Sources of
Impairment
Tuscarawas R. SW
of Canal
Lewisville
2005 3.0 EWH FULL N/A N/A
Tuscarawas R. at
Coshocton @ Kia
Bridge
2005 0.3 EWH FULL N/A N/A
Muskingum R.
Dst. Walhonding
R./Tuscarawas R.
2006 110.7 WWH FULL N/A N/A
Muskingum R. 1.0
Mi. Dst.
Coshocton WWTP
2006 107.6 WWH FULL N/A N/A
Muskingum R. 1.5
Mi. NE of
Conesville @ Twp.
Rd. 1182
2006 105.0 WWH FULL N/A N/A
Muskingum R. 1.5
Mi. Upst. Wills
Creek
2006 101.8 WWH FULL N/A N/A
WWH = Warmwater Habitat
Upst.= Upstream
Dst = Downstream
WWTP = Wastewater Treatment Plant
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 30 of 43
Table 12. Water Quality Criteria in the Study Area
Outside Mixing Zone Criteria Inside
Average Maximum Mixing
Human Agri- Aquatic Aquatic Zone
Parameter Units Health culture Life Life Maximum
Aluminum D μg/L -- -- -- -- --
Ammonia-N (Summer) mg/L -- -- 0.4 -- --
Ammonia-N (Winter) mg/L -- -- 5.6 -- --
Antimony D μg/L 4300 -- 190 900 1800
Arsenic μg/L -- 100 150 340 680
Barium μg/L -- -- 220 2000 4000
Benzo(a)anthracene D μg/L 0.49 C -- -- -- --
Beryllium D μg/L 280 100 52 440 890
Bis(2-
ethylhexyl)phthalate μg/L 59 C -- 8.4 1100 2100
Boron D μg/L -- -- 3900 33000 65000
Bromomethane D μg/L 4000 -- 16 38 75
2-Butanone (Methyl ethyl
ketone) D mg/L -- -- 22000 200000 400000
Butyl benzyl phthalate D μg/L 5200 -- 23 130 260
Cadmium μg/L -- 50 5.3 14 27
Calcium mg/L -- -- -- -- --
Chlorides mg/L -- -- -- -- --
Chlorine, Total Residual mg/L -- -- 0.011 0.019 0.038
Chloroform μg/L 4700 C -- 140 1300 2600
Chloromethane (Methyl
chloride) μg/L -- -- -- -- --
Chromium μg/L -- 100 190 4000 8000
Hexavalent Chromium
(Dissolved) μg/L -- -- 11 16 31
Chrysene D μg/L 0.49 C -- -- -- --
Cobalt D μg/L -- -- 24 220 440
Copper μg/L 1300 500 21 35 70
Cyanide, Free mg/L 220 -- 0.012 0.046 0.092
Cyanide, Total mg/L -- -- -- -- --
Diethyl phthalate D μg/L 120000 -- 220 980 2000
Fluoranthene D μg/L 370 -- 0.8 3.7 7.4
Fluoride D mg/L -- 2 -- -- --
Iron μg/L -- 5000 -- -- --
Lead μg/L -- 100 22 420 840 C = Carcinogen D = This parameter was found in the effluent of another discharger in this interactive segment.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 31 of 43
Table 12. Water Quality Criteria in the Study Area (continued)
Outside Mixing Zone Criteria Inside
Average Maximum Mixing
Human Agri- Aquatic Aquatic Zone
Parameter Units Health culture Life Life Maximum
Magnesium mg/L -- -- -- -- --
Manganese D μg/L -- -- -- -- --
Mercury B ng/L 12 10000 910 1700 3400
Methylene chloride
(Dichloromethane) μg/L 16000 C -- 1900 11000 22000
Molybdenum D μg/L -- -- 20000 190000 370000
Napthalene D μg/L -- -- 21 170 340
Nickel μg/L 4600 200 120 1100 2100
Nitrate + Nitrite mg/L -- 100 -- -- --
Nitrite mg/L -- -- -- -- --
Nitrogen, Total Kjeldahl mg/L -- -- -- -- --
N-Nitrosodiphenylamine
D μg/L 160 C -- -- -- --
Orthophosphate,
Dissolved (as P) mg/L -- -- -- -- --
Pentachlorophenol D μg/L 82 C -- -- -- --
Phenanthrene D μg/L -- -- 2.3 31 61
Phenol D μg/L 4600000 -- 400 4700 9400
Phenolics μg/L -- -- -- -- --
Phosphorus mg/L -- -- -- -- --
Potassium mg/L -- -- -- -- --
Pyrene D μg/L 11000 -- 4.6 42 83
Selenium μg/L 11000 50 5 -- --
Silver μg/L -- -- 1.3 8.5 17
Sodium mg/L -- -- -- -- --
Strontium μg/L -- -- 21000 40000 81000
Sulfates D mg/L -- -- -- -- --
Tetrachloroethylene D μg/L 89 C -- 53 430 850
Thallium D μg/L -- -- 17 79 160
Tin D μg/L -- -- 180 1600 3200
Titanium D μg/L -- -- -- -- --
Total Filterable Residue mg/L -- -- 1500 -- --
2,4,6-Trichlorophenol D μg/L 65 C -- 4.9 39 79
Zinc μg/L 69000 25000 270 270 550 B = Bioaccumulative Chemical of Concern (BCC) C = Carcinogen D = This parameter was found in the effluent of another discharger in this interactive segment.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 32 of 43
Table 13. Instream Conditions and Discharger Flow
Parameter Units Value Basis
Upstream Flows
Tuscarawas River
7Q10 cfs annual 279 USGS gage #03129000, 1921-2003 data
1Q10 cfs annual 266 USGS gage #03129000, 1921-2003 data
30Q10 cfs summer 320. USGS gage #03129000, 1921-2003 data
winter 566 USGS gage #03129000, 1921-2003 data
Harmonic Mean Flow cfs annual 1116 USGS gage #03129000, 1921-2015 data
Mixing Assumption % average 97.6 Stream-to-discharge ratio
% max 97.6 Stream-to-discharge ratio
Walhonding River
7Q10 cfs annual 249 USGS gage #03138500, 1921-1991 data
1Q10 cfs annual 103 USGS gage #03138500, 1921-1991 data
30Q10 cfs summer 288 USGS gage #03138500, 1921-1991 data
winter 430. USGS gage #03138500, 1921-1991 data
Harmonic Mean Flow cfs annual 821 USGS gage #03138500, 1921-1991 data
Mixing Assumption % average 97.6 Stream-to-discharge ratio
% max 97.6 Stream-to-discharge ratio
Instream Hardness
Tusc. Below WestRock CP mg/L annual 255 STORET, 2003-05, n=12
Muskingum comb. stations mg/L annual 264 STORET, 2015-16, n=13
Instream pH S.U. summer 8.34
Survey Dst Coshocton WWTP, 2016,
n=95
winter 7.7 Coshocton WWTP 901, 2007-08, n=5
Instream Temperature ºC summer 26.7
Survey Dst Coshocton WWTP, 2016,
n=95
winter 8.0 Coshocton WWTP 901, 2007-08, n=5
USGS = United States Geological Survey
WWTP = Wastewater treatment plant
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 33 of 43
Table 13. Instream Conditions and Discharger Flow (Continued)
Parameter Units Value Basis
Discharge Flows
Coshocton WWTP 001 cfs(MGD) design 6.81 (4.4) NPDES Permit Application
AK Steel 001 cfs(MGD) 95th % 4.18 (2.7) DSW Permits Staff
AEP Conesville 001 cfs(MGD) 95th % 33.4 (21.6) DSW Permits Staff
AEP Conesville 801 (Intake) cfs(MGD) avg. 64.2 (41.5) NPDES Permit Application
WestRock CP 002 cfs(MGD) 95th % 13.8 (8.9) DSW Permits Staff
WestRock CP 003 cfs(MGD) 95th % 4.6 (3.0) DSW Permits Staff
WestRock CP 004 cfs(MGD) 95th % 0.28 (0.18) DSW Permits Staff
Background Water Quality
All Segments
Bis(2-ethylhexyl)phthalate µg/L annual 0 No representative data available.
Chlorine, Total Residual mg/L annual 0 No representative data available.
Hexavalent Chromium
(dissolved) µg/L annual 0 No representative data available.
Cyanide, Free µg/L annual 0 No representative data available.
Molybdenum µg/L annual 0 No representative data available.
Silver µg/L annual 0 No representative data available.
DSW = Ohio EPA Division of Surface Water
MGD = million gallons per day
NPDES = National Pollutant Discharge Elimination System
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 34 of 43
Table 13. Instream Conditions and Discharger Flow (Continued)
Parameter Units Value Basis
Background Water Quality
Muskingum River
Ammonia-N mg/L summer 0.075 Coshocton WWTP 801, 2007-08, n=3
Ammonia-N mg/L winter 0.103 Coshocton WWTP 801, 2007-08, n=5
Tuscarawas River
Arsenic µg/L annual 2 STORET; 8 values, 3<MDL, 2003-04
Barium µg/L annual 57 STORET; 8 values, 0<MDL, 2003-04
Cadmium µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Chromium µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Copper µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Iron µg/L annual 2175 STORET; 8 values, 0<MDL, 2003-04
Lead µg/L annual 2.2 STORET; 8 values, 5<MDL, 2003-04
Mercury µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Nickel µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Selenium µg/L annual 0 STORET; 8 values, 8<MDL, 2003-04
Total Filterable Residue mg/L annual 396 STORET; 8 values, 0<MDL, 2003-04
Zinc µg/L annual 16.3 STORET; 8 values, 3<MDL, 2003-04
Walhonding River
Arsenic µg/L annual 2.53 STORET; 3 values, 3<MDL, 2016
Barium µg/L annual 64.3 STORET; 3 values, 0<MDL, 2016
Cadmium µg/L annual 0 STORET; 3 values, 3<MDL, 2016
Chromium µg/L annual 0 STORET; 3 values, 3<MDL, 2016
Copper µg/L annual 0 STORET; 3 values, 3<MDL, 2016
Iron µg/L annual 379 STORET; 3 values, 0<MDL, 2016
Lead µg/L annual 0 STORET; 3 values, 3<MDL, 2016
Mercury µg/L annual 0 No representative data available.
Nickel µg/L annual 2 STORET; 3 values, 2<MDL, 2016
Selenium µg/L annual 0 STORET; 3 values, 3<MDL, 2016
Total Filterable Residue mg/L annual 323 STORET; 3 values, 0<MDL, 2016
Zinc µg/L annual 0 STORET; 3 values, 3<MDL, 2016
MDL = method detection limit
STORET = United States Environmental Protection Agency Storage and Retrieval Data Wareh
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 35 of 43
Table 14. Summary of Effluent Limits to Maintain Applicable Water Quality Criteria
Outside Mixing Zone Criteria Inside
Average Maximum Mixing
Human Agri- Aquatic Aquatic Zone
Parameter Units Health culture Life Life Maximum
Ammonia-N (Summer) mg/L -- -- 18.2 -- --
Ammonia-N (Winter) mg/L -- -- 497.1 -- --
Arsenic B μg/L -- 4267 A 1912 A 3192 A 680
Barium μg/L -- -- 1526 13081 A 4000
Bis(2-
ethylhexyl)phthalate μg/L 7278 A -- 294 27528 A 2100
Calcium D mg/L -- -- -- -- --
Chlorides D mg/L -- -- -- -- --
Cadmium B μg/L -- 8413 A 252 A 474 A 27
Chlorine, Total Residual mg/L -- -- 108.2 A 136.5 A 0.038
Chloroform D μg/L -- -- -- -- --
Chloromethane (Methyl
chloride) D μg/L -- -- -- -- --
Chromium B μg/L -- 12336 A 6658 100130 A 8000
Hexavalent Chromium
(dissolved) μg/L -- -- 546 A 567 A 31
Copper μg/L 40284 A 15494 A 193 A 235 A 70
Cyanide, free mg/L 38450 A -- 0.596 A 1.631 A 0.092
Cyanide, total D mg/L -- -- -- -- --
Iron μg/L -- 157407 -- -- --
Lead μg/L -- 12182 A 733 10480 A 840
Magnesium D mg/L -- -- -- -- --
Mercury C ng/L 12 10000 A 910 1700 3400
Methylene chloride
(Dichloromethane) D μg/L -- -- -- -- --
Molybdenum B μg/L -- -- 1590000 A 10750000 A 370000
Nickel B μg/L 567331 A 24568 A 4174 A 27544 A 2100
Nitrate + Nitrite B mg/L -- 17223 -- -- --
Nitrogen, Total Kjeldahl
D mg/L -- -- -- -- --
Orthophosphate,
Dissolved (as P) D mg/L -- -- -- -- --
Phenolics D μg/L -- -- -- -- --
A Allocation must not exceed the Inside Mixing Zone Maximum B Parameter would not require a WLA based on reasonable potential procedures, but allocation requested by Permits Group. C Bioaccumulative Chemical of Concern (BCC), WQS must be met at end-of-pipe, unless the requirements for an exclusion are met as
listed in 3745-2-08 (L). D No WLA required for this parameter (or no applicable criteria).
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 36 of 43
Table 14. Summary of Effluent Limits to Maintain Applicable Water Quality Criteria (continued)
Outside Mixing Zone Criteria Inside
Average Maximum Mixing
Human Agri- Aquatic Aquatic Zone
Parameter Units Health culture Life Life Maximum
Phosphorus D mg/L -- -- -- -- --
Potassium D mg/L -- -- -- -- --
Selenium B μg/L 438756 1994 59 -- --
Silver B μg/L -- -- 103 A 481 A 17
Sodium D mg/L -- -- -- -- --
Strontium D μg/L -- -- -- -- --
Total Filterable Residue mg/L -- -- 10815 -- --
Zinc μg/L 2138000 A 774401 A 2412 A 1747 A 550 A Allocation must not exceed the Inside Mixing Zone Maximum B Parameter would not require a WLA based on reasonable potential procedures, but allocation requested by Permits Group. D No WLA required for this parameter (or no applicable criteria).
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 37 of 43
Table 15. Parameter Assessment
Group 1: Due to a lack of numeric criteria, the following parameters were not evaluated at this time.
Calcium Chlorides Chloromethane
Cyanide, total Magnesium
Orthophosphate, Dissolved
(as P)
Potassium Phenolics Phosphorus
Sodium Total Kjeldahl Nitrogen
Group 2: PEQ < 25 percent of WQS or all data below minimum detection limit. WLA not required. No
limit recommended; monitoring optional.
Arsenic Cadmium Chloroform
Chromium Methylene chloride (Dichloromethane) Molybdenum
Nickel Nitrate + Nitrite Selenium
Silver Strontium
Group 3: PEQmax < 50 percent of maximum PEL and PEQavg < 50 percent of average PEL. No limit
recommended; monitoring optional.
Ammonia-N (S&W) Barium Bis(2-ethylhexyl)phthalate
Hexavalent Chromium
(dissolved) Copper Cyanide, Free
Iron Lead Total Filterable Residue
Zinc
Group 4: PEQmax ≥ 50 percent, but < 100 percent of the maximum PEL or PEQavg ≥ 50 percent, but < 100
percent of the average PEL. Monitoring is appropriate.
No parameters meet the criteria of this group.
PEL = preliminary effluent limit
PEQ = projected effluent quality
WLA = wasteload allocation
WQS = water quality standard
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 38 of 43
Table 15. Parameter Assessment (continued)
Group 5: Maximum PEQ ≥ 100 percent of the maximum PEL or average PEQ ≥ 100 percent of the average
PEL, or either the average or maximum PEQ is between 75 and 100 percent of the PEL and
certain conditions that increase the risk to the environment are present. Limit recommended.
Limits to Protect Numeric Water Quality Criteria
Recommended Effluent Limits
Parameter Units Period Average Maximum
Chlorine, Total
Residual mg/L Summer -- 0.038
Mercury ng/L Annual 12 1700
PEL = preliminary effluent limit
PEQ = projected effluent quality
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 39 of 43
Table 16. Final Effluent Limits for Outfall 001
Concentration Loading (kg/day)a
30 Day Daily 30 Day Daily
Parameter Units Average Maximum Average Maximum Basisb
Temperature °C - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Dissolved Oxygen mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Total Suspended Solids mg/l 30 45d 432 647d EP, BPT
Oil & Grease mg/l -- 10 -- -- EP, WQS
Ammonia mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Nitrate+Nitrite mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Phosphorus mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Orthophosphate, Dissolved
(as P) mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - -
SB1
Free Cyanide mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Arsenic µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - -
BTJ, Mc
Iron µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ, Mc
Selenium µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ, Mc
Barium µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ, Mc
Nickel µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Silver µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Strontium µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Zinc µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ, Mc
Cadmium µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Lead µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ, Mc
Chromium µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Copper µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, BTJ, Mc
Hexavalent Chromium
(Dissolved) µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - -
EP, M, BTJ
E. coli #/100 ml 126 284d -- -- WQS
Chloroform µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - Mc
Methylene chloride µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - Mc
Bis(2-ethylhexly)Phthalate µg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - Mc
Flow Rate MGD - - - - - - - - - - - Monitor - - - - - - - - - - - - EP, Mc
Chlorine, Total Residual mg/l -- 0.038 -- --
WLA/IMZM,
RP
Mercury, Low Level ng/l 12 1700e 0.0002 0.0284 WQS, RP
Acute Toxicity
Ceriodaphnia dubia TUa - - - - - - - - - - - Monitor - - - - - - - - - - - - WET
Pimephales promelas TUa - - - - - - - - - - - Monitor - - - - - - - - - - - - WET
pH, Maximum SU 9.0e WQS
pH, Minimum SU 6.5f WQS
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 40 of 43
Total Filterable Residue mg/l - - - - - - - - - - - Monitor - - - - - - - - - - - - BTJ
Carbonaceous Biochemical
Oxygen Demand (5 day) mg/l 25 40d 416 666d EP/BPT
a Effluent loadings based on average design discharge flow of 4.4 MGD.
b Definitions
BPT = Best Practicable Waste Treatment Technology, 40 CFR Part 133, Secondary Treatment Regulation
BTJ = Best Technical Judgment
EP = Existing Permit
M = Division of Surface Water NPDES Permit Guidance 1: Monitoring frequency requirements for Sanitary
Discharges
RP = Reasonable Potential for requiring water quality-based effluent limits and monitoring requirements in
permits (OAC 3745-33-07(A))
SB1 = Implementation of Senate Bill 1 (ORC 6111.03
WET = Minimum testing requirements for whole effluent toxicity [OAC 3745-33-07(B)(11)] OR Reasonable
potential for requiring water quality-based effluent limits and monitoring requirements for whole effluent
toxicity in NPDES permits [OAC 3745-33-07(B)] OR FOR LAKE ERIE BASIN Requiring water quality-
based effluent limits and monitoring requirements for whole effluent toxicity in NPDES permits [40 CFR Part
132, Appendix F, Procedure 6 and OAC 3745-33-07(B)]
WLA = Wasteload Allocation procedures (OAC 3745-2)
WLA/IMZM = Wasteload Allocation limited by Inside Mixing Zone Maximum
WQS = Ohio Water Quality Standards (OAC 3745-1)
c Monitoring of flow and other indicator parameters is specified to assist in the evaluation of effluent quality and treatment plant
performance.
d 7 day average limit. e Maximum concentration. f Minimum concentration.
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 41 of 43
Attachment 1. Mercury Data from Pollutant Minimization Program
Date Influent (ng/l) Effluent (ng/l) Reduction
Jan-12 40.8 15.5 62%
Feb-12 21.5 14.3 33%
Mar-12 13.9 8.9 34%
April-12 31.2 4.4 86%
May-12 17.3 20.6 19%
June-12 31.4 13 59%
July-12 93.5 20.6 78%
Aug-12 13.2 9.1 31%
Sept-12 16.8 3.8 77%
Oct-12 17.4 9.4 46%
Nov-12 26.6 26.3 1.1%
Dec-12 22.8 11.1 51%
Jan-13 193 9.5 95%
Feb-13 39.7 6.5 84%
Mar-13 24.2 6 75%
April-13 53 13.9 74%
May-13 11.5 12.2 6.1%
June-13 36.7 13.3 64%
July-13 13.8 16.6 20%
Aug-13 22.2 15 32%
Sept-13 31.8 12.5 61%
Oct-13 23.7 16.3 31%
Nov-13 159 30.9 81%
Dec-13 63.1 12.9 80%
Jan-14 17.1 13.8 19%
Feb-14 14 7.7 45%
Mar-14 59.5 11.3 81%
April-14 14.2 7.3 49%
May-14 32.9 13.5 59%
June-14 31.1 22.7 27%
July-14 25.2 15.1 40%
Aug-14 57 14.1 75%
Sept-14 51.4 15 71%
Oct-14 16.3 13.6 17%
Nov-14 17.2 9.4 45%
Dec-14 98.5 11.6 88%
Jan-15 15 12.2 19%
Feb-15 54.3 6.3 88%
Mar-15 63.9 20.3 68%
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 42 of 43
Date Influent (ng/l) Effluent (ng/l) Reduction
April-15 95.3 51.1 46%
May-15 82.3 24.5 70%
June-15 55.9 1.1 98%
July-15 9.23 19.5 0%
Aug-15 9.67 8.99 7.0%
Sept-15 236 6.8 97%
Oct-15 55.6 10.2 82%
Nov-15 90.9 26.9 70%
Dec-15 28.3 10.8 62%
Jan-16 29.3 14.6 50%
Feb-16 70.6 21.6 69%
Mar-16 69.3 11.6 83%
April-16 35 16.6 53%
May-16 76.1 16.1 79%
June-16 392 48.1 88%
July-16 193 95.2 51%
Aug-16 190 19.7 90%
Sept-16 59.4 42.9 28%
Oct. 16 65.7 10.9 83%
Nov-16 47.2 7.99 83%
Dec-16 8.16 11.8 45%
Jan-17 6.96 13 87%
Feb-17 25.5 6.7 74%
Mar-17 13.8 5.1 63%
April-17 52.8 4.5 91%
Attachment 2. Mercury Data from Pollutant Minimization Program (continued)
Fact Sheet for NPDES Permit Renewal, Coshocton Wastewater Treatment Plant, 2017
Page 43 of 43
Addendum 1. Acronyms
ABS Anti-backsliding
BPJ Best professional judgment
CFR Code of Federal Regulations
CMOM Capacity Management, Operation, and Maintenance
CONSWLA Conservative substance wasteload allocation
CSO Combined sewer overflow
CWA Clean Water Act
DMR Discharge Monitoring Report
DMT Dissolved metal translator
IMZM Inside mixing zone maximum
LTCP Long-term Control Plan
MDL Analytical method detection limit
MGD Million gallons per day
NPDES National Pollutant Discharge Elimination System
OAC Ohio Administrative Code
Ohio EPA Ohio Environmental Protection Agency
ORC Ohio Revised Code
ORSANCO Ohio River Valley Water Sanitation Commission
PEL Preliminary effluent limit
PEQ Projected effluent quality
PMP Pollution Minimization Program
PPE Plant performance evaluation
SSO Sanitary sewer overflow
TMDL Total Daily Maximum Load
TRE Toxicity reduction evaluation
TU Toxicity unit
U.S. EPA United States Environmental Protection Agency
WET Whole effluent toxicity
WLA Wasteload allocation
WPCF Water Pollution Control Facility
WQBEL Water-quality-based effluent limit
WQS Water Quality Standards
WWTP Wastewater Treatment Plant