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TRIANGLE J COUNCIL OF GOVERNMENTS

DRAFT REPORT

Water Conservation and Reuse Feasibility Study

AUGUST 7,1992

CAMP DRESSER & McKEE Raleigh, North Carolina CDM environmcnrrl e n p i n ~ r s . scientists,

planners. k mrnapmeai consulmars

August 6, 1992

Ms. Kimberly Brewer Director of Resource Conservation Triangle J Council of Governments

Post Office Box 12276 Research Triangle Park, North Carolina 27709

- 100 Park Drive

Re: Water Conservation and Reuse Feasibility Study Draft Report

Ms. Kimberly Brewer:

Qmp Dresser & McKee (CDM) is pleased to transmit herewith (10) copies of the draft report for the Water Conservation and Reuse Feasibility Study project.

We have reviewed data provided by the Triangle J Council of Governments (TJCOG), met several times with the TJCOG Water Conservation and Water Reuse subcommittees to discuss our approach and intermediate findings, and spoke with staff members of the North Carolina Division of Environmental Management on regulatory issues. Based on the methodology approved by both the Water Conservation and Reuse subcommittees, we have evaluated the feasibility of implementing water conservation and reuse strategies in the Triangle J Region from the technical and economic aspects as required in our contract.

Based on our evaluations, we conclude that water conservation and reuse measures are feasible, and implemenution of at least moderate programs of water conservation and reuse are " m e n d e d for all the communities studied. Certainly, a host of other factors could have major impacts on the programs and should be considered before actual implementation.

We wish to express our appreciation for the cooperation and assistance extended us by yourself and members of the Water Conservation and Water Reuse subcommittees. We look forward to meeting with you and the Water Conservation and Water Reuse Steering committees to discuss this report on August 13, 1992.

Very truly yours,

n L Roberts, P.E.

\

K. Richard Tsang, Ph. Project Manager

1 .o

1 .:I 1 2 1.3

2.0

2.1 2.2 2.3

3.0

3.1 3.2

3.3

3.4

Triangle J Council of Governments Draft Report

Table of Contents

INTRODUCTION

Background Objectives Study Scope

STUDY AREA DESCRIPTION

Water and Wastewater Systems Analysis of Water Use and Wastewater Flows Surveys of Major Water Users

WATER CONSERVATION AND REUSE ALTERNATIVES

Introduction Potential Water Conservation Measures

3.2.1 Public Education 3.2.2 Building and Development Codes 3.2.3 Retrofit Existing Development 3.2.4 Leak Detection and Repair 3.2.5 Water Audits 3.2.6 Variable Rate Structures 3.2.7 Water Use Ordinances

Regulatory Issues Related to Reuse

3.3.1 Purpose of Regulations 3.3.2 Add itiona I Considerations

Summary of Potential Reuse Scenarios

3.4.1 Urban Reuse 3.4.2 Industrial Reuse 3.4.3 Environmental and Recreational Reuse 3.4.4 Groundwater Recharge 3.4.5 Agricultural Reuse 3.4.6 System Configurations

1-1 1-1 1-3

2-1 2-1

2-12

3-1 3-2

3-3 3-4 3-6 3-8 3-8 3-9 3-9

3-10

3-10 3-12

3-14

3-16 3-16 3-17 3-15 3-15 3-19

i

Table of Contents (Continued)

4.0

4.1 4.2

-

4.3

5.0

5.1 5.2

5.3

6.0

6.1 6.2

POTENTIAL WATER CONSERVATION AND REUSE SCENARIOS

Introduction Summary of Water Conservation Scenarios

4.2.1 Description of Scenarios 4.2.2 Conservation Scenarios for Individual Communities

Water Reuse Scenarios

TECHNlCAL AND ECONOMIC EVALUATIONS OF SCENARIOS

Introduction Evaluation of Water Conservation Scenarios

5.2.1 Considerations in Evaluation Procedure 5.2.2 Costs of Water Conservation Measures 5.2.3 Benefits/Savings from Water Conservation Scenarios 5.2.4 Loss in Revenues from Water Conservation 5.2.5 Impacts of Water Conservation on Customer Rates 5.2.6 Summary of Evaluations for Individual Communities

Evaluation of Water Reuse Scenarios

5.3.1 Considerations in Evaluation Procedures 5.3.2 Costs for Implementation 5.3.3 BenefitsEavings 5.3.4 Revenue Loss 5.3.5 Impact on User Rates

CONCLUSIONS AND RECOMMENDATIONS

Water Conservation Water Reuse

APPEND1 CES

A

B

C

Summary Tables of Water Conservation Scenarios

Supplemental Calculation Tables for Evaluation of Water Conservation Scenarios

Supplemental Calculation Tables for Evaluation of Water Reuse Scenarios

4-1 4-1

4-1 4-3

4-7

5-1 5-2

5-2 5-3 5-4 5-7 5-7 5-8

5-9

5-9 5-9

5-10 5-1 2 5-12

6-1 6-3

ii

1.0 INTRODUCIION

1.1 Backeround -

The Triangle J Council of Governments (TJCOG) has received a 205u) grant to study water

conservation and non-potable reuse in the Triangle Region. In March, 1992, after a consultant

selection process the Triangle J Water Conservation and Reuse Steering Committee selected

Camp Dresser & McKee (CDM) to conduct a technical and economic feasibility analysis on

water conservation and reuse in the Triangle Region. The authorizing document for these

services is the contract dated April 8, 1992 between TJCOG and CDM.

1.2 Obiectives

The goal of this study is to investigate the feasibility of implementing water conservation and

reuse strategies in the Triangle Region. The Triangle Region consists of many communities, but

for practical reasons, only six major water systems are examined in the study. These systems

include Cary, Durham, Orange Water and Sewer Authority (OWASA), Raleigh, Sanford, and

Smithfield. The objective of the study is:

"TO provide a conceptual evaluation of the technical and economic feasibility of

incorporating water conservation and reuse into the long range water management plans

of the six major municipal systems in the Triangle Region."

1.3 Study Scope

The general scope of services for this study includes the following:

Conduct a preliminary screening of the most promising water conservation and

re use strategies 0 Characterize water use within each of the water systems and identify water use

customers for which water conservation and reuse strategies may be targeted

Define moderate, aggressive, and maximum water conservation and reuse

6512-1.2 1-1

programs for the six major water systems

Prepare conceptual level cost estimates for each water conseryation and reuse

program -

0 Compare the costs of non-potable water reuse and water conservation with

mnven t iona I approaches

Prepare a report summarizing the feasibility evaluation

Prepare a discussion paper on conservation and non-potable water reuse

regulations in selected U.S. areas and their applicability to North Carolina and the

Triangle Region

Prepare a discussion paper on conservation and non-potable water reuse systems

in selected U.S. areas and their applicability to North Carolina and the Triangle

Region.

65 12- 1.2 1-2

2.0 STUDY AREA DESCRIPTION

2.1 Water and Wastewater Systems

The Triangle J Region consists of communities in six counties, including Chatham, Durham,

Johnston, Lee, Orange, and Wake counties in central North Carolina. Six major water systems

in the Triangle J Region were studied. They are Cary, Durham, OWASA, Raleigh, Sanford, and

Smithfield. All of these systems have their own water and wastewater treatment facilities except

for Cary and Smithfield. Cary has been purchasing water from Raleigh but will have its own

water treatment plant on line in the near future. Smithfield owns a water treatment facility that

supplies water to a large area in Johnston County, but Johnston County owns the wastewater

treatment facility which is located in Smithfield. Tables 2-1 and 2-2 summarize the water and

wastewater treatment facilities within the study area. A total of seven water treatment plants with

a combined capacity of 157 mgd are located in the area of study. All water treatment facilities

use conventional coagulation and filtration at this time. There are nine wastewater treatment

plants with a combined capacity of approximately 120 mgd. Treatment levels range from

secondary with settling ponds to filtration preceded by chemical or biological phosphorus

removal.

-

2.2

In order to provide an evaluation of the potential effectiveness of a water conservation program

and/or a water reuse program, it is necessary to characterize the existing water uses within the

proposed service area. In addition, i t is necessary to characterize the availability of reclaimed

water that may be available for reuse within the proposed service area.

ANALYSIS OF WATER USE AND WASTEWATER FLOWS

Tables 2-3 through 2-5 summarize this information based on data provided to CDM by the

TJCOG. Table 2-3 summarizes safe yield, the 1990 average daily water use, maximum day

water use, total water treatment capacity and projected water demands for the six service areas

in question. It is interesting to note that the 2010 water demand projections for Raleigh of 70

MGD exceeds the 66 MGD reported safe yield. As a group, the 1995 projected water demands

6512-1.2 2- 1

Table 2-1

~

- f i ry 1 12.0

- Durham 2 52.0

OWASA 1 12.5

Raleigh 1 62.5

Sanford 1 12.0

Smithfield 1 6.0

Summary of Water Treatment Facilities

Conventional Coagulation and filtration, disinfection

Conventional Coagulation and filtration disinfection

Gmventional Coagulation and filtration disinfection




Number of Total Plants Capacity

(MGD) Form of Treatment -

-

Table 2-2

Summary of Wastewater Treatment Facilities

Total Number of Capacity

GrY

Durham

OWASA

Raleigh

Sanford

Smithfield*

Plants

2

3

1

1

1

1

Form of Treatment

10.4

30

8

60

6.8

4

Northside Plant - secondary & micro screen filter, chlorine disinfection

Southside Plant - secondary & settling ponds, chlorine disinfection

Northside - Chemical Phosphorus removal, chlorine disinfection

Farrington - Biological phosphorus removal with filters, chlorine disinfection

Durham County - Chemical phosphorus removal and filters, chlorine disinfection

Biological phosphorus removal, chlorine disinfection ~ _ _ _ _ _ ~

Tertiary filter and UV disinfection

Tertiary filters, chlorine disinfection

Biological phosphorus removal, with chemical backup and UV disinfection

* WWTP operated by Johnston County.

6512-1.2

DXAL-87

Raleigh

Sm i thfield

TABLE 2-3

SUMMARY OF WATER SUPPLY

66 33.4 49.3

18 3.1 4.8

12.0

52.0

Sanford I 19 I 4.2 I 6.4 5.3 6.2 8.3

26.5 30.0 37.6 Durham

OWASA

~ ~~

42 25.0 30.2

24 7.5 11.6

62.5 I 45 I 53.0 I 70.0*

Qry

Total

6.0 I 3.2 I 4.0 I 3.6

16 6.2 9.6

185 79.4 11 1.9

12.5 I 7.5 I 8.5 I 11.0

12.0 I 7.4 I 9.5 I 10.8

157.0 I 94.9 I 111.2 I 141.3

* Projected use exceeds reported safe yield.

I I '

2.89 / 11

BO9 / 1

1.07 / 32

TABLE 2-4

SUMMARY OF WATER CUSTOMER BY CITY

NR / 18 2.6 / 9

NR .27 I 23

NR NR

Customer Classification

1.6 I 7

NR

.23 I 4

5.80

8 .

Raleigh I 10.71 / 39 I 11.09 / 41

3.3 I 15 2.20 / 10

3.16 / 43 .61 I 8

.35 1 6 .42 I 7

12.92 6.1

18 8 1 I

Smithfield 1 .77 / 66 1 NR

Sanford I 2.27 / 68 I NR

Durham I 10.90 / 50 I 4.00 / 18

OWASA 1 31.6 I 43 1 0.45 / 6

QrY I 4.27 I 69 1 0.92 1 15

Total Water Use 1 32.08 I 16.46

22 I 44 I %

*

NR-Not reported

% provided does not add up to 100%

I I S ’ ,

QrY 7.8

Tofal 69.7

TABLE 2-5

SUMMARY OF WASTEWATER FLOWS

10.4 9.1

99.2 131 .O**

* Purchased from Johnston County

** Exceeds reported design capacity

NR Note reported

represent approximately 51 percent of the total safe yield. By the year 2010 the TJCOG area

water demands will be approximately 76 percent of the 185 MGD reported safe yield.

-

Table 2-4 presents a breakdown of water use by residential, commercial, industrial, institutional

and unaccounted for water. As noted in the table a complete record for each city was not

provided. However, based on the information that was reported the residential customer typically

accounts for the majority of the potable water demand representing from 39 (Raleigh) to 68

percent (Sanford) of the total water use. The City of Raleigh reports the highest commercial

demand representing 41 percent of the total. OWASA indicates on average 6 percent of i t s water

was used for commercial purposes. The Towns of Sanford and Smithfield represent the extreme

for industrial water uses with 32 and 0.7 percent of the total water demand, respectively.

Institutional use ranges from 43 percent (OWASA) to 18 percent (Raleigh) of the water use.

Finally, unaccounted for water was generally reported to be less than 10 percent of the total water

demand with the exception of Smithfield which reported 23 percent of its water unaccounted for.

Table 2-4 also provides a summary of the average current use by customer classification of the

six systems. While the record is not complete it is apparent that the residential customers

represent the single largest water use classification with approximately 44% of the total combined

demand. Commercial customers represent the next largest users with 22% of the total combined k AMF.

demand. €nsw&cm a1 use accounts and unaccounted for water represent the smallest water

demand with each category representing approximately 8% of the total water demand.

* .

Table 2-5 presents a summary of the wastewater flows within the TJCOG study area. Each

service area is characterized by the average 1990 discharge, total treatment capacity and projected

2010 flows. Four of the service areas, Raleigh, Smithfield, Durham and OWASA indicate that

the year 2010 projected flows will be in excess of the current treatment capacity. As a group,

the projected 2010 flows are approximately 132 percent of the existing treatment capacity.

As part of this report an estimate of the volume of water now being used for irrigation is

required. In order to develop this estimate, meteorological and water and wastewater data was

compiled and a linear regression analysis performed using the monthly values of each parameter

6512-1.2 2-7

from 1986 through 1990. In general a regression analysis compares one parameter to another to

determine if they are related. For example a comparison of season to average temperature would

draw November, December and January to be associated with cooler temperatures and June, July,

and August associated with warmer temperatures. I n addition to identify correlations, a

regression analysis will provide a measure of how strong the correlation is. Also the regression

analysis will indicate if the correlation is positive (Le., an increase in another) or negative (Le.,

an increase in parameters is associated with a decrease in another). All parameters used in the

linear regression are listed below:

-

8 Year

Monthly Rainfall

8 Monthly Temperature

Monthly Water and Wastewater Flows For Each City

The results of this statistical evaluation are summarized in Table 2-6. A 'I+" symbol indicates

a significant positive correlation between the two parameters. A 'I-'' indicates a significant

negative correlation. A blank indicates no significant correlation was found between the two

parameters. A discussion of Table 2-6 is given below.

Year

The year is positively correlated to both water and wastewater flows in Raleigh,

Sanford, Durham and Cary. This suggests that 1) These communities are

experiencing growth over the period evaluated and 2) this growth is reflected in

both the water and wastewater flows. The municipalities in Smithfield and

OWASA do not indicate significant growth by their water or wastewater flows.

Monthly Rainfall

For four of the municipalities riinfall was positively correlated with wastewater

flows (i.e., wastewater flows increase when rainfall increases). These areas were

6512-1.2 2-8

S A W + + +

+

DW +

+ +

+

DWW + +

+

OW O W CW CwW + +

+ -+ + + + T + + -

+ + +

DWW - + + + + + + - - ow +

O W cw +

cww

TABLE 2-6 RESULTS OF LINEAR REGRESSION ANALYSIS 'I+" Indicates Significant (<0.05) Positive Correlation "-" Indicates Significant (<0.05) Negative Correlation

I I RAIN TEMP I RW R W W I SW SWW SAW I + + I t

I RAIN + + + + +

+ RWW + sw

MTH - MONTH YR- YEAR RAIN - MONTHLY RAINFALL (IN)

SWW SAW I + 1 + 1 - 1 + 1 +

+ 1 - 1 + 1 I -+ TEMP - AVERAGE MONTHLY TEMPERATURE DEGREES F RW - RALEIGH MONTHLY WATER USE RWW - RALEIGH MONTHLY WASTEWATER FLOWS SW - SMITHFIELD MONTHLY WATER USE SWW - SMITHFIELD MONTHLY WASTEWATER FLOWS SAW - SANFORD MONTHLY WATER USE S A W - SANFORD MONTHLY WASTEWATER FLOWS DW - DURHAM MONTHLY WATER USE DWW - DURHAM MONTHLY WASTEWATER FLOWS OW - OWASA MONTHLY WATER USE O W - OWASA MONTHLY WASTEWATER FLOWS CW - CARY MONTHLY WATER USE CWW - CARY MONTHLY WASTEWATER FLOWS

Raleigh, Sanford, Durham, and OWASA. This would suggest that wastewater flows are

being impacted by infiltration and inflow.

-

0 Monthly Temperature

Temperature shows a positive correlation to the water use patterns for all

municipalities represented in Table 2-6. This correlation suggests that as

temperatures rises, so does water use. This in turn suggests that water demand

increases may be driven by irrigation demands. Wastewater flows in Sanford and

OWASA also indicate a positive correlation. It is unclear why this is occurring.

0 Monthly Water and Wastewater Comparison

The remainder of the table presents the correlation between the water and

wastewater flows of one municipality to the water and wastewater flows of

another. In general, the water use patterns are all related to one another indicated

that each system is using water in a similar manner. The wastewater flow pattems

of one municipality are also closely related to that of another. Negative

correlations between water demands and wastewater flows are also observed

suggesting that as water demands increase wastewater flows decrease and vice

versa.

In addition to the regression summarized in Table 2-6 several multiple regressions were

developed using various combinations of input parameters. In a multiple regression analysis two

parameters are compared to a third parameter. The results of one such regression (Smithfield

water vs. temperature and rainfall) are shown graphically in Figure 2-1. This figure clearly

shows the correlation between water demand and rainfall and temperature strengthening the

contention that water demands are being influenced by irrigation use. The question at hand is

how much potable water is currently being used for irrigation.

Without elaborate field studies a straightforward method of estimating non-potable water use is

to compare water demands to wastewater returns with the assumption being that water not

65 12-1.3 2-10

4 0 5 0 6 0 10 2 0 30

MONTHS OF DATA (12/31/90) (1/30/86)

- HISTORIC SMItHFiELD WATER USE

- - - - PREDICTED WATER USE

CDM MULTIPLE REGRESSION OF SMITHFIELD WATER USE AS A FUNCTION OF TEMPERATURE AND RAINFALL

Fpe No. 2-1 W a m s 6 nianagemenl ansidtanlr

returning to the wastewater treatment plant has been used in a consumptive manner such as

irrigation. These comparisons are summarized in Table 2-7. The results are described as

follows: - -

On an average annual basis the difference between water demand and wastewater flows

is approximately 14 percent. -

0 A review of the peak month difference indicates an average difference of 37 percent.

This maximum difference tends to occur in a period when irrigation would be expected

to be at a maximum.

The results summarized in Table 2-7 cannot be considered a definitive evaluation of the irrigation

demand currently being experienced by each of the six municipalities under evaluation. This is

apparent by the fact that there are numerous negative numbers in the early spring for a majority

of the municipalities suggesting that average wastewater flows were greater than the average

water delivered. Factors affecting this evaluation are any customers not returning

wastestreams to the sewer system (septic tanks for example); customers currently using well

water on-site that discharge a wastestream into the sewer and finally; infiltration and inflow.

It is difficult, if not impossible, to quantify all inputs and abstractions that may affect the

accuracy of the comparison made in Table 2-7. However, using the correlation between rainfall

and wastewater flows previously discussed in Table 2-6, the wastewater flows for Raleigh,

Sanford, Durham and OWASA have been corrected for rainfalls (based on a linear regression of

wastewater flows and rainfall), and from that the percent difference between water and

wastewater was recalculated. For example, if a regression analysis predicted a positive

correlation between rainfall and wastewater flows, a zero rainfall value was used to estimate

wastewater flows in the absence of rainfall. This recalculation for corrected wastewater flows

is given in Table 2-8.

From the corrected values given in Table 2-8 the estimated annual average difference between

water and wastewater has increased from 14 percent to 19 percent. However, the I/l correction

65 12- 1.2 2-12

DM1-07

February

March

I I "

1 -3

-2 0

TABLE 2-7

AVERAGE % DIFFERENCE BETWEEN MONTHLY WATER AND

WASTEWATER FLOWS BY CITY (UNCORRECTED)

4

-2

-1 -19 -8 -4

-3 -15 -7 -5

April

May

June

-3 2 4 8 -3 1 2

4 21 12 13 8 15 12

18 38 44 27 23 23 29 ~~~

July

August

September

October I

26 39 49 30 36 22 34

12 33 40 24 26 22 26

15 29 39 18 24 21 24

17 I 30

November

Decem be r

Average

21 I 14 21 21 14 17 10 1 I 16

15 18 17 11 9 -7 11

11 19 22 14 10 8 14

22 I 22

TABLE 2-8 AVERAGE % DIFFERENCE BETWEEN MONTHLY WATER AND

WASTEWATER FLOWS BY CITY (CORRECTED)

Per Table 2-6 the correlation between rainfall and wastewater flows was not significant for this system and flow are the same as given in Table 2-7

had little to no impact on the peak season calculations of the difference between water and

wastewater flows. The tohl average corrected and uncorrected percent difference between water

and wastewater flows is given in Figure 2-2. Figure 2-2 includes the exjxctedseasonal change

in evapotransportation (ET) based on information provided by the agricultural-extension agent.

Both the corrected rind uncorrected differences between water and wastewater flow show a

65 12- 1.2 2-13

35

30

25

20

15

10

5

0

-5

-1 0

-X- Unconverted for In (Table 2-7) - Converted for In (Table 2-8) - (ET) Evapotransportat ion

2.0

1.5

P i

1.0 g P

0.5

0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

TOTAL AVERAGE, CORRECTED AND UNCORRECTED PERCENT DIFFERENCE BETWEEN

WATER AND WASTEWATER FLOW

CDM o n v v m t a l e n g ~ ~ s . uimttsrs, planners 1 m a t u p m t OolUuhMLI

Figure No. 2-2

seasonal change similar to that of ET again supporting the assumption that water use is

influenced by irrigation. Individually, the correction for rainfall increased the projected annual

average percent difference between water and wastewater from five to ten percent for those

municipalities to which i t was applied. -

S;”an, Based on the results of Table 2-8, nonpotable demands average 19 percent of the total potable

water demand in the TJCOG area. Seasonally, the average non-potable demand may be as high

as 32 percent with maximum non-potable demands approaching 45 percent of the potable

demand.

2.3 SURVEY OF MAJOR WATER USERS Section 2.1 and 2.2 provide general information on water and wastewater flows in the study area.

In order to assess the potential for water conservation and reuse in the study area, specific

information regarding the nature of water use and use patterns is essential. A water use survey

was therefore conducted on the major water users in each system. The survey was aimed at

gathering data on potable and nonpotable usages of major water consumers.

A telephone survey was conducted by each utility in the study area. A sample of the survey

form used is provided in the appendix. Information gathered in the survey was used to develop

the water conservation and reuse scenarios described in Section 4.0. Most users are not able to

quantify different on-site water uses, however, mainly bemuse of a lack of internal water meters,

most users were able to provide an estimate of \*arious uses as a percentage of total consumption.

6512-1.2 2-15

3.0 WATER CONSERVATION AND REUSE ALTERNATIVES

,^_ & L/* ,,-a*' 7,- ,A ' ' 3.1 INTRODUCTION d- -

There has historically been little need for water conservation in North Carolina. North

Carolina and the Triangle J Region have enjoyed abundant water supply resources with the

exception of a few communities who have had temporary shortages during unusual drought

periods. Despite abundant water resources, many North Carolina communities have begun

evaluating water conservation and/or reuse for i t s economic and environmental benefits.

Triangle J COG'S funding of this water conservation and water reuse feasibility study reflects

the increased interest in operating water and sewer utilities with maximum efficiency, the

latest technologies, and a keen environmental awareness.

-

The cost and planning period for developing new water supplies are both rapidly increasing

because of tightening drinking water standards and more stringent permitting requirements.

This has led many communities to consider water conservation and/or reuse as part of their

long-term plan for sustaining a good-quality, reliable water supply. Most communities who

are evaluating new water supply sources are considering sources with lower water quality

than their existing sources. This is because the high quality sources tend to have small

watersheds and little upstream development and wastewater discharges. The high-quality

sources also tend to have low yields, and they are susceptible to drought. When looking to

develop new sources with a more reliable yield, but lower water quality, communities are

wise to implement a water conservation/reuse program that can maximize the beneficial use

of the highest quality water supply.

The difference in quality between an existing supply and a new supply may be exacerbated in

the future because of the new state watershed protection regulations. Existing water supplies

will receive added protection from deteriorating water quality by obtaining a water supply

(WS) classification. However, a community may need to consider a river or stream that is

not classified as a water supply as a future source. Such a source would not have had the

6512-1.2 3- 1

The remainder of this section describes the water conservation and water reuse alternatives

that may be considered for use in the Triangle J Region. Section 3.2 describes the major

categories of water conservation strategies. Section 3.3 describes the regulatory issues related

to water reuse in North Carolina. Section 3.4 contains a summary of the potential reuse

seenarios along with a discussion of the methods used to screen the potential reuse

alternatives for those that are most likely to be cost-effective. Based on the screening results

a detailed cost-effectiveness analysis of selected reuse alternatives was performed, and is

presented in Section 4.0.

3.2 POTENTIAL WATER CONSERVATION MEASURES

An estimated range of potential savings in water use that may result from implementing these

measures are also provided. These ranges reflect the uncertainty in results of implementing

water conservation measures. There are a number of factors that contribute to the success of

water conservation measures within an area that includ6 cultural differences, demographics,

and climate. Some factors, such as public acceptance of a program, can be influenced by a

comprehensive public education program, but other factors can not be changed.

---l -4 ,--- -

The ranges of reductions in water use are estimated based on results of conservation programs

in other areas around the country. I t is acknowledged that there is a wide variance in the

effectiveness of water comervation. Also, some results from the most effective conservation

programs were found during crisis situations. Therefore, i t is important to use the water use

reduction estimates for planning purposes only. A large-scale water conservation program

should not be implemented without first conducting one or more pilot scale studies to better

determine the effectiveness of water conservation measures within the local setting.

It is also important to note that many of the water conservation measures discussed below

may have overlapping benefits. Therefore, the estimated reductions in water use resulting

from these measures may not be additive. This is an impornnt consideration in developing

the water conservation scenarios that are presented in Section 4.1.

65 12-1.2 3-2

3.2.1 Public Education

A comprehensive public education program is an essential part of any water conservation

program. Some communities in the Triangle J Region have already begun to implement some

basic public education measures, such as billing inserts giving customers advice on ways to

reduce their water bills.

Other items that may be included in a public education program include:

e contacts with the news media through press releases and/or scheduled events;

development of brochures and/or posters for distribution to customers;

e production of video tapes advocating water conservation that can be shown on

local community access television or that can be distributed to schools, special

interest groups, and others;

a contests and awards may be designed to promote friendly competition

schools or other clubs to reduce water use; , p. It j

I *

among

a conferences and seminars are also an effective way to increase public

awareness of water resources and water conservation/reuse issues. The

conference that is planned for the Spring of 1993 to be sponsored by the

Triangle J COG will be an excellent opportunity to promote water conservation

and reuse to interested utility staff, local elected officials, and other interest

groups or concerned citizens.

Water savings from these activities are difficult to predict and will vary based on the range

and magnitude of the activity and on the public response. For this study, it was assumed that

the range of potential savings from public education is from 0 to 6 percent.

6512-1.3 3-3

3.2.2 Buildinr and Development Codes

Building and development codes are a good way for the community to mandate water

ccmservation to future users. The state of North Carolina has recently enacted more stringent

plumbing codes requiring the use of low-flow fixture and reduced-flush toilets that will be

effective January 1, 1993. These regulations require that the types of plumbing fixtures

described in Table 3-1 be installed on new or new-retrofit construction.

Communities cannot implement plumbing codes that are stricter than the state’s codes unless

a code variance is issued by the state. For this study, it was estimated that the new state

plumbing codes would result in a savings of 15 to 20 percent of water use from new

residential, commercial, and institutional buildings. This estimate is based on national

averages for indoor residential water consumption and expected reductions in flows from the

new plumbing codes.

Additional measures that could be implemented by communities may fall under development

codes, such as a subdivision ordinance. Landscaping requirements may be imposed that

restrict the type of plants that can be installed to those with low water demands (xeriscaping).

Codes may also be implemented that require apartments to have individual water meters,

rather than a central metering system where residents pay for water at a fixed rate in their

monthly rent. Residents are more likely to conserve water if they have their own monthly

water bill that is directly dependent on their water use. Xeriscaping and apartment

submetering are both programs that are implementable through local zoning and ordinances.

Water heaters should be placed as close as possible to the point of usage and hot water pipes

should be well-insulated to minimize the length of time that water must be run to obtain hot

water for showering, etc. Alternatively, instant electric hot water heaters located at the point

of use may be considered where appropriate.

6512-1.2 3-4

TABLE 3-1

SUMMARY O F FIXTURE FLOW LIMITATIONS TO BE REQUIRED EY NEW NC

PLUMBlNG CODES (Effective 1/1/93)

-

Plumbinp Fixture Water Use Allowed

Water closets, flushometer tank

or close-coupled 2-piece gravity-

flush type

Water closets, flushometer valve

floor mount

1.6 gal/flush

3.5 gaI/flush

Water closets, wall mount 3.5 gaI/flush

Residential sink and lavatory faucets 3.0 gal/minute

Public lavatory faucets, metering 0.25 gakyc le

Public lavatory faucets, non-metering 0.5 gal/minute

Showerheads 3.0 gal/minute

65 12-1.2 3-5

Savings in water use of up to 5 percent were assumed for implementing these additional

measures above the savings expected from implementation of the new state plumbing

regulations. - -

33.3 Retrofit Existing Development

n e retrofit of existing development with water-conserving fixtures and toilets can be an

effective method of reducing water use, especially in residential areas that have a large

percentage of development that occurred before 1980. In North Carolina, a change in the

plumbing codes in 1980 reduced the maximum flush size of toilets to 3.5 gallons, from 5 to 7

gallons per flush. Therefore, communities where a large percentage of their residential

development occurred before 1980, such as Sanford and Smithfield, have the most potential to

benefit from a residential retrofit program.

One retrofit strategy is to distribute retrofit kits containing faucet aerators and low-flow

showerheads. These kits also contain toilet bags that reduce the quantity of water per flush

and dye tablets that help to determine if a toilet is leaking. Faucet aerators cost about $0.25

to $0.50 per unit and a low-flow showerhead can be purchased for between $3 and $4.

The effectiveness of a retrofit program is dependent on the installation rate of the retrofit

devices, which is dependent on the distribution method and the public education program

(Maddaus, 1987). A bulk mailing or central depot method are the least-costly methods of

distribution, but they only typically result in an installation rate of 15 to 20 percent. Door-to-

door distribution of retrofit kits with a follow-up installation if needed typically results in

installation rates of 30 to 50 percent. The most successful installation method is typically

direct installation, which results in a 60 to 70 percent installation rate. However, customers

may reject direct installation as a disturbance of privacy. All of these estimated participation

rates are highly dependent on the success of the public education program. If customers do

not understand the need for installing the devices and the benefits that they will receive, then

the participation rate will be relatively poor. Anecdotal evidence suggests that a well-

I 6512-1.2 3-6

marketed bulk mail program can have a higher participation rate than a direct installation

program.

-

The estimated potential savings for a location where retrofit devices are installed is

approximately 15 to 25 percent for residences and 5 to 20 percent for commercial and

institutional customers. A lower and more varied range is estimated for commercial alld

institutional customers because of the variety of other water uses that may be found at these yp” ’5 P-J-*- 3 sites. Y

3.2.4 Leak Detection and Repair

Leak detection and repair is an example of one measure that individual utilities may use to

conserve water. Utility conservation measures are a very important part of any water

conservation program, not only because they save water, but because it is difficult to acquire

public participation in a program if there is the perception that the utility is not maximizing

their own efforts to conserve water. Other measures that can be considered by a utility to

conserve water and reduce unaccounted-for water are water meter testing and replacement and

reducing operational pressure in the distribution system.

A goal of 10 to 15 percent unaccounted-for water is reasonable for a typical water distribution

system. AI1 systems in this study reported unaccounted-for water that was less than 15

percent.

3.2.5 Water Audits

Water audits are important for customers where there is uncertainty how water is being used.

For residential and many commercial sectors, there is a fairly consistent patter of water use

and a set of programs with some expected impact. For industrial customers, even those

manufacturing similar projects, the pattern of water use may be quite different because of the

age and location of the plant and changes in manufacturing processes. I t is more difficult to

predict what types of water conservation programs will be effective in an industrial plant.

65 12- 1.2 3-7

In addition, water audits are often used to encourage industrial plants to implement

conservation measures on their own. The utility provides the road map and an estimate of the

benefits that will occur if implemented. The private company then makes thedecision of

which of the proposed benefits are economical. The ultimate decision remains' with the

plvate sector. This approach also minimizes the utility's need to justify making investments

OF purchasing equipment for profit making entities.

From the water user surveys that were conducted as part of this study, and that are discussed

in Section 2.3, many of the major water users in the Triangle J Region were favorable to

participating in a water audit of their facility. I t was also evident from these surveys that

very few facilities had an ongoing water conservation program. Therefore, there appears to

be a good potential for reduction of industrial and commercial water use in this area. -1 9

3.2.6 Variable Rate Structures

The term variable rate structures is used in this study to cover a number of possible water

conservation strategies, all of which are aimed at reducing water use by the users for

economic reasons.

The most typical variable rate structure is an increased block structure whereby the unit rate

charged for water increases after a quantity of water is exceeded. This type of rate structure

has been shown to reduce water use by up to 8 percent for residential use and by up to 35

percent for some types of businesses (SWFWMD, 19SS; Mann, 1987). Multiple blocks may

be used to continue to discourage very high water use.

Water rates may also be varied by season. Typically, water supply facilities must be designed

to meet peak demands during the summer months. By increasing water rates during these

periods, it may be possible to reduce demand during this critical period. I t is important that

billing is performed at least monthly with seasonal rates so that customers are aware of the

impact of increased water rates on their summer water bills.

6512-1.2 3-8

Other possible rate structures include those that vary by user class. For example,

commercial/industriaI users may pay a higher unit rate than a residential customer. -

For this study, it was assumed that variable rate structures may produce watefsavings in the

system ranging from 0 to 10 percent. -

3.2.7 Water Use Ordinances

Water use ordinances are typically designed to limit outdoor water use during peak summer

months of water use. Ordinances may limit or prohibit water use for irrigation during certain

times of the day or during alternating days of the week. Ordinances may also be aimed at

reducing water use for cleaning cars, driveways, or other equipment. Ordinances may be

designed to include different stages of implementation that would be activated depending on

the degree of water reduction needed.

Ordinances must be implemented in conjunction with a program that notifies the public when

the ordinance is activated and the degree or stage that is currently in place. Depending on the

urgency of the program, an enforcement program may also be needed.

Savings from implementation of water use ordinances may curtail outdoor water use up to 75

percent. However, for this study, water savings from water use ordinances were not counted

while evaluating the benefits of a water conservation program. These savings were not

counted because of desire of many utilities to keep operational flexibility in case of a drought

period. Therefore, i t is not recommended that implementation of new water supply facilities

be delayed because of savings in water use that are seen or expected from a water use

ordinance.

A water shortage plan is an essential part of any water conservation program. At a minimum,

all jurisdictions should develop an emergency water shortage plan that may be implemented

during a drought condition. A primary component of a water shortage plan will be a water

use ordinance.

65 19-1.2 3-9

3.3

As with water and wastewater facilities, water reclamation programs are subject to state

regulations. The State of North Carolina Department of Environment, Health,-and Natural

Resources, Division of Environmental Management oversees reclamation p r o p m s . The

specific elements of the regulations controlling reuse are contained in Administrative Code

Section: 15A NCAC 2H.0200 (Amended effective August 1, 198s). This section will

provide a summary of the existing regulations as they pertain to this reuse study.

REGULATORY ISSUES RELATED T O REUSE

3.3.1 Purpose of Regulations

The purpose of the current regulations is to address waste streams that are not discharged to

surface water. The rules lay out permit application procedures and fees and required

supporting information. Detailed plans and specifications are required for all facilities

covered under the rule. Other information to be submitted includes:

0 A general location map

0 A description of the origin, type, and flows in question

0 Possible development of environmental documentation where construction of facilities

is funded by public monies

0 Development of an erosion control plan where more than one acre of land is cleared.

In developing the background information of a spray irrigation site the following elements

must be addressed:

0 Topographic map of the site not exceeding 10 feet or 25 percent of the total site relief.

0 Location of proposed facilities and wells, pits and quarries, springs, lakes, ponds or

other surface drainage features within 500 feet of the site.

65 12-1.2 3-10

9 Comprehensive hydrogeologic investigation of the site.

9 A site management plan prepared by an agronomist.

0 : A complete chemical analysis of the effluent.

9 Proposed location and construction details of a monitoring well network.

0 Information on the location, construction details, and primary usage of all wells within

500 feet of the site.

The setbacks required for spray irrigation are summarized in Table 3-2.

3.3.2 Additional Considerations

The current North Carolina regulations are geared to address land application as a means of

effluent disposal as opposed to beneficial use of the reclaimed water. This is consistent with

many state regulations, although comprehensive water reclamation and reuse regulations have

been implemented in water-short states such as Arizona, California, Florida, and Texas. The

North Carolina regulations do allow for the use of reclaimed water on golf courses and other

public access areas.

In order to irrigite these areas the state requires aerated equalization basin with a minimum

capacity of 25 percent of the daily design flow. Essential treatment units must be duplicated

to assure reliability. The monthly average Total Suspended Solid (TSS) must be less than 5

m g L with a daily value of less than 10 m a . Fecal coliform levels must be less than 1/100

ml.

After meeting the specified water quality requirements the effluent is discharged to a pond

with a five day detention period with restricted public access. Following the five day

6512-1.2 3-1 1

Description

Residence or public access area not pwt of the project.

Any property line

Drainage systems

I Setback (feet)-

150

100

400

Any private or public water supply source. 100

I Streams classified as WS-I, 11, 111, or B 100 I

6512-1.2 3-12

detention reclaimed water may be discharged to irrigation ponds. The size of these irrigation

ponds is to be determined by a water balance for the worse case condition on record.

- As one of the realiability requirements automatically activated standby power

an alternative the supplier may develop an operating protocol to prevent substandard water

inio the system. A certified operator of a class equivalent to the class plant must be on call

24 hours/day. Effluent piping must be separated from the potable system and no cross

connection are allowed. Spigot on the irrigation system are prohibited. The maximum

irrigation rate allowed is 1.75 in/wk. Irrigation is limited to between 11:OO p.m. and three

hours prior to opening of the facility. Signs notifying users that the site is irrigated with

treated wastewater are required.

required. As

Discussion of Regulation

As noted previously, the North Carolina regulations are focused on land application.

However, the irrigation of public access sites such as golf courses is specifically addressed. It

is assumed that under these same provisions other public access sites such as parks could also

be served. The rules do not specifically address other reuse alternatives that may be available

to the municipalities involved in this study such as industrial cooling water, residential irrigate

and the irrigation of agricultural crops. Due to the lack of comprehensive reuse regulations,

the implementation of reuse programs will require close coordination with the regulatory

agencies.

3.4

Up until recently the application of reclaimed water to the land was primarily viewed as a

means of diverting that water from surface water discharge. While such "land treatment

systems" certainly can be credited with recycling a resource, these benefits were secondary to

the goal of pollution abatement. With pressures increasing on potable supplies, reclaimed

water is now rightfully viewed as a potential source of water in many states.

SUMMARY OF POTENTIAL REUSE SCENARIOS

65 12-1.2 3-13

A breakdown of fresh water demands within the United States is summarized in Figure 3-1.

Agricultural irrigation represents approximately 40 percent of the total demand. Thermal

electric is approximately the same with 39 percent of the total demand. Public and domestic

water uses are those typically provided for in systems similar to those being eTaluated in this

pyoject, and they account for 11 percent of the total fresh water demands within the United

States. Commercial and industrial demands consume approximately eight percent of the fresh

water with livestock uses representing one percent of the total demand.

In evaluating the potential benefits of reuse and/or urban water conservation, those water uses

typically associated with residential homes are of interest. Figure 3-2 summarizes the

national average estimate of water use by category for this customer classification. Outdoor

uses for lawn irrigation and other non-potable demands is given as 32 percent. The next

greatest water use is toilet flushing with 28 percent of the total demand. It is interesting to

note that neither of these uses require water of potable quality and by the estimates given in

Figure 3-2, 60 percent of the typical residential home's water use could be supplemented with

non-potable sources. Laundry and dishwashing account for 14 percent of the potable water

uses; cooking and drinking three percent; and bathing approximately 23 percent of the total

residential water use.

.

The summary given in Figure 3-2 is based on a national average. Camp Dresser 8: McKee

has had the opportunity to investigate various water use patterns in the eastern United States

where the water supplier provides a first meter for interior potable water uses and a second

meter for exterior irrigation demand. An evaluation of such meters in southwest Florida

indicated that 78 percent of the total water going to a house with two meters was being used

for irrigation. A study of similar meters in Mt. Pleasant, South Carolina suggests that

between 20 and 30 percent of the total water demand is being used through the second meter.

In this report reclaimed water will be directed at non-potable uses in an effort to offset the

use of high quality potable water where such quality is not required. In such "reuse systems"

the primary goal will be water conservation. However, the pollution abatement benefits

6512-1.2 3-14

39%

@"wddagl7sen,abrm*. Source = Solley et al., 1988 p b m d mwugm" OwuRanh Figure Na.91

Thermoelectric

Public and Domestic

0 Industrial and Commercial

Agricultural Irrigation

Livestock

12%

I CDM U.S. FRESH WATER DEMANDS BY MAJOR USERS, 1985.

14%

32 %

OutdoorUse

Toilet Flushing

Laundry and Dishes

Bathing

I Cooking and Drinking

28%

CDM RESIDENTIAL WATER USAGE COMPARISON AS A PERCENTAGE OF AVERAGE DAILY USE

F Q U ~ No.3-2

realized by "land treatment systems" will also be realized as water is diverted from existing

discharges for beneficial reuse. Figure 3-3 provides an example of a multiple use, reuse

distribution system. A brief description of some of the more common uses ofreclaimed

water is given below. -

-

3A.1 Urban Reuse

As experience with the reclamation of wastewater has increased, procedures and protocol

have been developed that provide a high degree of assurance that a pathogen free product,

safe for most non-potable uses, can be consistently produced. This in turn allows for the use

of reclaimed water in less restrictive settings than dedicated land application sites. Initially,

urban reuse customers were made up exclusively of large turf areas such as golf courses,

parks and in some cases condominiums. As noted in the previous section such uses appear to

be permittable under current North Carolina regulations. However, some states allow

reclaimed water to be distributed through a dual distribution system to single family residents.

The primary use of such water at this time is for urban landscape irrigation. However, in

several states, non-irrigation urban uses are now being investigated. These might include dust

control, equipment washdown, and toilet flushing. I n Irvine, California some office buildings

to use reclaimed water for toilet and urinal flushing. The dual distribution system now under

construction in Cape Coral, Florida, will provide fire protection to that city, as well as

irrigation.

3.4.2 Industrial Reuse

Nation-wide industrial water use accounts for only about eight percent of the total water use

demand. However, where such sites are located in the vicinity of reclamation facilities,

industrial reuse may offer a significant savings of potable water. The most common use of

reclaimed water is for cooling water makeup. Depending on the quality of the reclaimed

water, i t is often possible for it to be used in as many cycles of concentration as may be

practiced by using traditional sources. Additional treatment by the user is sometimes required

to prevent scaling and fouling of the cooling tower. Other industrial uses may include boiler

feed water and process water. However, it is often necessary to provide additional treatment

\ 6512-1.2 3-15

SPECIAL NEED CUSTOMERS

WATER RECV\MATION

FACILITY

URBAN REUSE CUSTOMERS

COUUCRCIN CUSIOUCRS SmC,t ~ uul,l rAU5-f CUSlOUCRI

nrpuup i o GOlr COURSC I R W U l l O N STSlCU (1IOp. i )

ON Sltt ': SIORAGC (COtT COURSC PONO)

AGRICULTURAL REUSE

I OH-YlC MI1 Y . I

CDM MULTIPLE REUSE DISTRIBUTION SYSTEM

of reclaimed water to meet the stringent water quality requirements of these uses. The

implementation of an industrial reuse program will result in the consumption of a large

percentage of that water delivered to the site. However, a wastewater stream - referred to as

blowdown is often generated and will require disposal considerations. -

3.4.3 Environmental and Recreational Reuse

Potential uses of reclaimed water for recreational and environmental purposes range from the

maintenance of landscape ponds such as water hazards on golf course fairways to full scale

development of water based recreational sites for swimming, fishing and boating. A common

environmental/recreational reuse strategy is to create new wetlands or to enhance natural

wetlands that have been damaged through dredging. Such systems also provide additional

renovation to the reclaimed water stream as it travels through the wetlands system. Wetlands

restoration and man-made wetlands typically result in a discharge to surface water.

Reclaimed water may also be used to create recreational impoundments. The treatment

requirements for such impoundments typically vary with the expected degree of human

contact. Nutrient control is generally required to avoid unsightly algae blooms. In arid states

the use of reclaimed water to develop recreational impoundment has allowed for lakes and

waterways to be created where none exist naturally. Where such lakes do exist naturally,

reclaimed water can be used to maintain lake levels throughout the year. The primary goal of

a recreational impoundment will be the development of an aesthetically pleasing environment.

However, in other countries (Israel and China for example) commercial fish production in

reclaimed water impoundments is widely practiced. Such practices are currently being

investigated in the United States.

3.4.4 Groundwater Recharee

The purposes of groundwater recharge using reclaimed water are (1) to establish salt water

intrusion barriers in coastal aquifers, (2) to provide further treatment for reuse, (3) to augment

potable or non-potable aquifers, (4) to provide storage of reclaimed water or (5 ) to control or

prevent groundwater ground subsidence. These uses are distinctly different from a percolation

pond or drainfield which seeks only to dispose of an eftluent. Groundwater aquifers provide

65 12-12 3-16

a natural mechanism for storage and transmission of reclaimed water. Other uses of water are

often seasonal requiring either large storage facilities or alternative means of disposal when

demands are low. In many cases, suitable sites for surface storage are not available or are not

economically feasible. Groundwater recharge may eliminate the need for s u r h storage

facilities. Also, groundwater aquifers may serve as a natural distribution system and reduce

the need for surface transmission systems. The successful implementation of a groundwater

recharge program is highly subject to the hydrogeologic conditions of the proposed area and

significant site specific studies are often required in designing such systems.

3.4.5 Acricultural Reuse

Agricultural reuse has enjoyed a long successful history of application in the United States,

with most major systems occurring in the arid states. As suggested in Figure 3-1, the actual

means by which reclaimed water may be put to agricultural use can be extremely varied.

This variability will also have a great impact on the required water quality. For example, the

use of open channel conveyance and flood irrigation can tolerate relatively poor quality water.

Somewhat better quality water is required for sprinkler irrigation to avoid clogging the

nozzles. A very high quality water often requiring additional filtration may be needed if

micro-jet or drip irrigation is employed. Agricultural reuse can be quite attractive where the

use of potable water or potable water sources for agricultural irrigation is extensive. In

addition, it is not uncommon to be able to deliver reclaimed water to a central point on an

existing agricultural operation for use with existing irrigation distribution systems already in

place. Agricultural irrigation may become an unattractive reuse option when agricultural

operations of the nature described above are not within easy reach of a wastewater treatment

facility. This is often the case as urban centers where wastewater/reclaimed water is

produced will tend to displace the agricultural uses in the same area. Investigation carried out

by the North Carolina Cooperative Extension Service indicate that the need for reclaimed

water for agricultural irrigation in the Triangle J area is minimal at this time. As such it is

unlikely agricultural reuse will be a significant factor in this reuse feasibility study.

65 12-1.2 3-17

3.4.6 System Con ficu ra t ions

Assuming that current reuse opportunities in the TJCOG area will consist primarily of urban

customers such as single- and multi-family homes, golf courses, parks, and commercial and

industrial customers Figure 3-4 illustrates a potential system configuration. la this scenario

the reuse demand is assumed to be less than the available supply in any month as illustrated

in the seasonal hydrograph. Where such a commitment is established the need for seasonal

storage to meet peak demands is avoided. However only about half of the reclaimed water

may be used beneficially. The remainder would continue to be disposed of by surface water

discharge.

Scenario I1 illustrated in Figure 3-5 includes seasonal storage facilities. The addition of

storage allows for commitments to exceed the available supply with the deficit made up by

water retrieved from storage. A discharge to surface water discharge will still be required to

dispose of water when the storage facilities are full or reclaimed water quality does not meet

the required standards for reclamation.

65 12-1.2 3-18

I

WASTEWATER - TREATMENT

PLANT

SYSTEM CONFIGURATION COMMERCIAL/NDUSTRIAL

SINGLE k uum CUSTOMERS FAMILY CUSOMERS

PRESSURE r $c&UNING

1

REPUMP TO GOLF COURSE IRRIGATION SYSTEM

SURFACE WATER DISCHARGE 1-1 OF EXCESS WATER OR WATER NOT MEETING REUSE STANDARDS

SEASONAL HYDROGRAPH

REUSE DEMAND

CDM SCENARIO No. 1

DUAL DISTRIBUTION WITH -~ ~

W-W -1YWS. ScI.nDSIS. SURFACE WATER DISCHARGE D U ~ A m v u p m n r a n i u t a n n Fgwe No. 3 - 4

SYSTEM CON FlGU RATION

REPUMP TO GOLF COURSE IRRIGATION SYSTEM

-

M J J A s 0 . N D J F M A

- WASTEWATER TREATMENT

- P M

G-

SINGLE I Muin CUSTOMERS FAMILY CUSTOMERS

PRESSURE r $ k . N I N C I

€3

SURFACE WATER DISCHARGE OF EXCESS WATER OR WATER NOT MEETING REUSE STANDARDS

SEASONAL HYDROGRAPH

SCENARIO No. 2 DUAL DISTRIBUTION, SURFACE STORAGE

AND SURFACE WATER DISCHARGE Faure No. 3-5 * I o . H w t W WI9ltW.n. W n D S I S . m- 1 m u u v m m r mrsr *ynn

4.0 SELECTED WATER CONSERVATION AND REUSE SCENARIOS

4.1 INTRODUCTION -

Of the many factors that go into development of conservation and reuse scenarios, this study

has focused on the economic and engineering considerations. Other considerations, such as

ietitutional and political factors can only be included after the development of a detailed

feasibility study in each of the six municipalities.

-

The water conservation and water reuse scenarios were developed for each community using

data from: (1) water and wastewater system profiles, (2) lists of the major water users for

each community, and (3) the results of the surveys conducted of the major water users in

each system. This data was provided by the Triangle J COG and/or one of the municipalities

involved in the study. The water system profiles contained much of the raw data regarding

the water and wastewater systems that was described in Section 2.0 of this report, as well as

projected water demands and wastewater flows for the study planning period through the year

2010.

The following sections describe the water conservation and water reuse scenarios for which

the cost-effectiveness evaluations were performed. Section 4.2 presents the water

conservation scenarios, and Section 4.3 presents the water reuse scenarios. The results of the

cost-effectiveness evaluations for these scenarios are presented in Section 5.

4.2 SUMMARY OF WATER CONSERVATION SCENARIOS

4.2.1 Description of Scenarios

Three water conservation scenarios have been developed for the communities serving each of

the five utilities included in the conservation study: the Town of Cary, the Orange Water and

Sewer Authority (OWMA), the City of Raleigh, the Town of Sanford, and the Town of

Smithfield. The three scenarios for each community have been labeled moderate, aggressive,

and maximum, as was suggested by the Triangle J COG. This section of the report will

describe the development of a moderate, aggressive, and maximum conservation scenario for

65 12- 1.2 4- 1

each of the five communities. To assist in developing specific conservation scenarios for

each community, water use reduction goals of 5, 15, and 25 percent were set for the

moderate, aggressive, and maximum conservation scenarios by the year 201 0, respectively.

Reduction goals are assumed to be compared to the projected water use in theyear 2010 (see

Tcble 2-1). The scenarios for each community consisted of an appropriate combination of the

water conservation measures described in Section 3.1 that were expected to produce

conservation results meeting the water use reduction goals.

The following general definitions of these three conservation scenarios were used as guides in

developing the specific water conservation scenarios for each community.

Moderate Scenario (5 percent reduction eoal bv the year 20101

The water utility will notify users that information is available upon request on water

conservation. The primary focus of the program will be on public education through

occasional press releases, water bill inserts, etc. Localized, voluntary retrofit programs

will be targeted where there is high potential for water savings with very little

expenditure. A water use ordinance will be developed for implementation during

extreme drought conditions. This program will require no additional staff or capital

expenditure.

Aggressive Scenario (1 5 percent reduction goal bv the year 201 0)

Retrofit programs will be expanded to include direct distribution of water saving

devices. Localized water audits will be considered where high potential for water

savings exists, and incentives will be provided for existing water users to conserve

water. Variable rate structures will be considered to discourage water use during peak

demand periods. Water use ordinances should be developed for implementation during

drought conditions. This program will require some additional staff and capital

expenditure.

6512-1.2 4-2

Maximum Scenario (25 percent reduction poal by the year 20101

Water conservation measures will be mandated and/or strongly encouraged through

water use ordinances and/or variable water rate structures. Building and development

codes more restrictive than the new state regulations will be consideretiby obtaining a

local variance. Retrofit of existing development may consist of direct installation of

water-saving fixtures and toilets. The utility will evaluate additional utility

conservation measures such as a stringent leak detection and control program. This

program will require additional staff and extensive capital projects.

;.

The characteristics of each community in terms of its water usage and wastewater production

were considered in formulating a program of water conservation measures that would best

meet the water conservation goals associated with each scenario.

The following subsections describe the major considerations in developing the water

conservation scenarios for each of the five study communities.

4.2.2 Conservation Scenarios for Individual Communities

Each of the conservation measures described in Section 3.2 of this report were considered for

inclusion in the moderate, aggressive, and maximum water conservation scenarios for each

community. This section describes the primary factors considered in determining the water

consewation measures that were most appropriate for each community. The scenarios were

designed so that the water reduction goals of 5, 15, and 25 percent were met with the most

appropriate combination of water conservation measures for each community. The

conservation scenarios for the Town of Cary, the Orange Water and Sewer Authority, the City

of Raleigh, the Town of Sanford, and the Town of Smithfield are shown in Tables 4-1

through 4-5, respectively.

4.2.2.1 Public Education

Public education was considered an essential part of any water conservation program and was

included in every scenario. The effectiveness of a public education program was assumed to

vary for each scenario, corresponding to the number of different of educational measures that

65 12-1.2 4-3

TABLE 4-1

Building/Development Codes

SUMMARY OF CONSERVATION SCENARIOS FOR THE - TOWN OF CARY -

State Regulations

Water Conservation Scenarios Moderate Water Use Reduction Goals: I 5 %

Add Develop. Codes

Door-to-door No

Public Education I Essential Add Develop.

Codes

Direct Install Door-to-door

Existing Program

No

Seasonal

Retrofit Existing Development Residential Commercial/Institutional

Existing Program

No

Seasonal

No No

Leak Detection and Repair I Existing

Program

C/UI Recycling (Water Audits)

Variable Rate Structures

No

No

Water Use Ordinances

I I Aggressive 15 96

Shortage Plan

Essential I Essential

Shortage Shortage

TABLE 4-2

~

Water Conservation Scenarios Water Use Reduction Goals:

Public Education


SUMMARY OF CONSERVATION SCENARIOS FOR THE- ORANGE WATER AND SEWER AUTHORITY

-

Moderate Aggressive Maximum 5% 15% 25 %

Essential Essential Essential State State Add Develop.

Regulations Regulations Codes

Retrofit Existing Development Residential Com merciaVInsti tu tional

Leak Detection and Repair

C/I/I Recvcling (Water Audits)

Bulk Mail Bulk Mail Existing Program

No

Door-to-door Door-to-door

Existing Program

No

Direct Install Door-to-door

Existing Program Top 20

Water Users ~~~



No Seasonal Seasonal

Shortage Shortage Shortage Plan Plan Plan

TABLE 4-3 -

~ ~~~

Public Education

SUMMARY OF CONSERVATION SCENARIOS FOR THE - CITY OF RALEIGH _ .


Water Conservation Scenarios Moderate Aggressive I Maxxzum 1 I Water Use Reduction Goals: I 596 I 1596

Bulk Mail BuIk Mail Existing Program

No

Door-tdoor Direct Install Door-to-door D o o r - t d w r

Existing Existing Program Program

Top 20 No Water Users

Building/Development Codes I Regulations I Regulations I Codes 1


Retrofit Existing Development Residential CommerciaI/Institutional



C/I/I Recycling (Water Audits) I I Water Use Ordinances Shortage Shortage Shortage I Pian I Plan

TABLE 4 4

I 1 Water Conservation Scenarios Moderate Aggressive Maximum Water Use Reduction Goals: 5 % 15 96 25 %

-

Public Education Essential Essential Essential

Building/Development Codes Regulations Regula ti ons Codes

Retrofit Existing Development

State State Add Develop.

Residential Bulk Mail Door-to-door Direct Install Commercial/Institutional No No No

Existing Existing Existing Leak Detection and Repair Program Program Program

Top 20 C/I/I Recycling (Water Audits) No No Water Users

Variable Rate Structures No Seasonal Seasonal

Water Use Ordinances Shortage Shortage Shortage Plan Plan Plan

TABLE 4-5

- Water Conservation Scenarios Moderate Water Use Reduction Goals: 5%

SUMMARY OF CONSERVATION SCENARIOS FOR THE - - TOWN OF SMITHFIELD

Aggressive Maximum 15% 25 %

Public Education





Regulations Regulations Codes

Bulk Mail Door-to-door Direct Install No No No

Existing Existing . Existing Program Program Program

Top 10 Top 20 C/VI Recycling (Water Audits) No Water Users Water Users




Shortage Shortage Shortage Plan Plan Plan

could be implemented and the amount of money spent on the program. Moderate programs

were assumed to get water savings of 0 to 2 percent; aggressive programs from 0 to 4

percent; and maximum programs from 0 to 6 percent. -

4.2.2.2 BuildingDevelopment Codes

Because the state of North Carolina has implemented stringent plumbing codes that become

effective January 1, 1993, all conservation scenarios were assumed to include the regulated

changes. For maximum scenarios, it was assumed that additional development codes, such as

those described in Section 3.2.2 would be implemented that would provide additional savings

beyond those received from the new state regulations. Savings from building/development

codes are only applied to new development in a community. Therefore for this study, savings

from these measures are deducted from the estimated future water demands for the planning

period between 1993 and 2010.

Communities that are expecting the largest amount of future growth in the planning period,

such as the Town of Cary, will receive the greatest benefits from building/development codes.

Therefore, these communities should give the most consideration to including additional

and/or more stringent measures to the building/development codes.

Water reductions from new building codes were estimated to be from 15 to 20 percent of

water use from new residential, commercial, and institutional development. Measures beyond

the state regulations were estimated to add a savings of 5 percent.

4.2.2.3 Retrofit Existing Development

In 1980, North Carolina revised their plumbing codes to require that most residential toilets

flush a maximum of 3.5 gallons/flush. Prior to this, flush rates of toilets ranged from 5 to 10

gallons/flush. Because of this change in the plumbing codes, communities who had most of

their residential development prior to 1980, such as the Towns of Sanford and Smithfield,

have the most potential for water savings from a residential retrofit program. Both Sanford

and Smithfield had more than 75 percent of their existing residential development before

1980. In contrast, the Town of Cary had only 40 to 45 percent of its residential development

6512-1.2 4-9

before 1980 and does not have as much potential for water savings by implementing a

residential retrofit program. Therefore, a retrofit program was not recommended under Cary's

modem te scenario. - -

a m m e r c i a l growth is roughly proportional to residential growth in most areas: therefore

m m e r c i a l retrofit was generally included in conjunction with residential retrofit unless the

percentage of commercial water use in the community was very small.

Water reduction from retrofit of institutional water users is often as good or better than that

from residential areas, especially if this institutional development is pre-1980 and consists of

users such as universities. Distribution costs may also be reduced for these types of facilities.

OWASA and Raleigh are good candidates for a commercialhnstitutional retrofit program.

Water reductions from a retrofit program were estimated by applying the potential water

reduction factors in Section 3.2.3 ofq5 to 20 percent saving to the water use of the residential

and/or commercial/institutionalddevelopment currently contained in the community. The

percent coverage of the distribution plan was also factored. An example using the

computation of water savings from a residential retrofit program for OWASA's maximum

water conservation scenario is presented below. The example computes the estimated percent

savings of the total water use in the year 2010 using an estimated savings of 15 percent from

a retrofit program that applies only to pre-1990 residential development.

4 4

Existing 1990 Residential Water Use 3.2 mgd

Year 2010 Total Water Use 11 mgd

Potential Savings from Retrofit

Installation coverage using a direct

installation method

Total Savings in 2010 water use =

15 percent

60 percent

3.2 mgd 1 11 mgd x 15% x 60% = 2.6%

The results of these computations for each community are presented in the tables in

Appendix A. Results presented in these tables are rounded to the nearest percent.

65 12-1.2 4-10

4.2.2.4 Leak Detection and Repair

No reductions in water savings were attributed to leak detection and repair for this study.

None of the communities in this study had unaccounted-for water percentages above the

recommended limit of 15 percent. -

4.2.2.5 Commercia I And us tria i/I ns t i tu t ional Water Audits

Commercial/industriaI/institutional (C/l/l) water audits were included as part of a maximum

conservation scenario for all communities with the exception of Cary. This measure has good

potential for water reduction for communities who have very large water users that consume a

significant percentage of the community’s water. However, water audits have a relatively

fixed cost per customer and therefore are most cost-effective on the largest customers. Cary

does not have any single water customers that consume a very large percent of their water.

The range of savings for water audits was estimated to be from 0 to 10 percent of the 1990

C/I/I water use. t &V ep P y P e

4.2.2.6 Variable Rate Structures

Rate structures that vary by season were included in the aggressive and maximum scenarios

for all five communities. Most communities in North Carolina receive their greatest water

demands during the summer months. Therefore, a rate structure that placed the highest rates

on water during the summer would be most justifiable and would provide the most benefits in

terms of reducing peak demand on the system. Variable rates structures were estimated to

reduce total water usage by 0 to 5 percent.

4.2.2.7 Water Use Ordinances

An emergency water shortage plan was included in every scenario for every community. A

shortage plan may include multiple stages that reflect the urgency of the need to reduce water

demand, as described in Section 3.3.6. Water use ordinances are often aimed at reducing

outdoor water use, as are variable rate structures for residential use. Because of the potential

of an overlap in the estimated water savings between variable rate structures and water use

ordinances, no savings were attributed to the water use ordinances in this study. In addition,

65 12-12 4-1 1

this measure is considered a mechanism for a water utility to maintain flexibility in i ts

operation by implementing the shortage plan on an as-needed basis.

- 4.3 WATER REUSE SCENARlOS - Based on the information provided by each utility on the water consumption and wastewater

discharges characteristics of the system as well as information gathered in the water use

survey, three water reuse scenarios were developed for each system. These three scenarios

are characterized as Moderate, Aggressive, and Maximum and vary from system to system.

To arrive at each scenario, a list of potential reclaimed water users was screened using a

number of criteria, including the estimated non-potable water use, proximity of the potential

users to reclaimed water sources, the degree of additional treatment required for reuse, the

seasonal variation in demand, and the reliability of reclaimed water demand. Table 4-YL summarizes these criteria and the standards for assigning ratings. In each water system, each

potential user was evaluated by these criteria and a rating was assigned under each criterion.

At the end of the evaluation process, the total score for each user was calculated. In

developing the three reuse scenarios for each water system, potential users with the highest

scores were targeted in the Moderate scenario, some users with lower scores were also

included in the Aggressive scenario. The Maximum scenario for each system was in general

an extension of the Aggressive scenario to include residential users. The selection of users

under each scenario not only depends on the total score but also on other factors such as the

presence of other users in the vicinity, and the actual distance from the reclaimed water

source as well as the estimated demand on reclaimed water. Tables 4-7 to 4-12 summarize

the evaluation of potential users for all six water systems. Under each scenario for each

table, a "1" indicates that the user is included in that scenario, and a "0" indicates that the

user is not included.

65 12-1.2 4-12

Table 4-6

Water Reuse Evaluation Criteria and Standards for Assigning Ratings -

-

Highest Reuse Potentia 1

Lowest Reuse Potential

Criteria Rating of 3 Rating of 2 Rating of 1

Minimum Water Use 2% of Total 1% of Total 0.5% of Total WW Flow WW Flow WW Flow

Proximity to Source within 2 within 5 within 10 miles miles miles

Additional Treatment None Minimal Extensive Needed

Seasonal Water Use > 9 mos. > 6 mos. > 3 mos.

Reliability of Demand

High Moderate Unknown

Bble 4-7

0.2

Safe Yield Avg. daily use Avg. daily discharges 0.1 0.1 0.2 1 Water Reuse

Scennriaa

16 MGD 6.184 MGD

7.78 MGD

Uscn Roy’s Rental IJniform (I) Cary SK l l igl i School (2) Ready hfixed Concrete Co. (3) I’ano Comp. Bowling Arms (4)

Annual Estimated 9iOFWW Minimum Class. Demand (hfG) Non-Pot (MG) Flow Water Use

C 4.8 1.9392 0.07% 0 INS 3.2 1.6 0.069; 0 I 2.9 2.9 0.10% 0 INS 5.5 0.00% 0 R 10. I 5.05 0.18% 0

hfobilc i s ta te Co. (5) IR I 20.0 1 10 I 0.35sc( 0 T.W. R u l t y Mobile llome (6’1 IK 7.7 I I 0.004rJ 0

ToSoum 0 1 3

Needed Water Use ofDemmd Score Mod. Am. Max. 3 3 2 1 0 0 0 3 2 0 0 0 0 0.7 3 2 2 1.5 0 0 0

1 I . ~- ~~

. I

American Airlines ( I 1) C 6.7 3.35 0.12% 0 nahlsen Inc (I 2) C 13.6 4.08 0.14%1 0 hfarriot Ilotcl(13) C 3.7 1.48 0.05% 0 Paragon Group (14) C 3.9 1.56 0.05% 0 II A G Realty ( I S ) C 3.2 1 .28 0.05% 0

0 2 1 1

L _ . , WJS Assoc. (16) C 3.1 1.24 0.04% 0 hiotels of Anierica (17) C 4.3 1.72 0.06% 0 K D I J Airport (18) C 116.8 46.72 1.65% 2

~

0 0 0 3 3 0 1 0 0 0 3 3 2 1.2 0 0 0

0 n n

IMotcl 6 (19) IC I 4.6 I 1.84 I 0.06RI 0

1 1 2 1

hfarriot Corp (20) C 3.9 1.56 0.OSs;l 0 Cnry Towne Cenlcr (21) C 13.0 5.2 O.lS%{ 0 Wake hfedical Ccnter 1221 INS 2.8 n2.s notsJ 0

3 3 0 0.8 0 0 0 0 0 0

3 3 1 1.2 0 0 0 3 3 1 1 0 0 0

I . ~.

, I

hfeny I-and d; Investment (23) R 3.2 I 1.6 O.OS%l 0 h icny l i n d & lnvalmcnt(24) R 3.2 I 1.6 0.WSll 0

Oxford Square l ( 7 ) Ikgcncy Park Corp. (8) I b r g Warner (9) SAS lnstitutc (101

. . thicrry land & lnvatmcnt (25) IR I 5.8 I 2.9 1 O.IO4rJ 0

R 5.8 2.9 O.lO%{ 0 C 10.1 0.007r.I 0 I 3.1 1.55 0.05’Xl 0 C 4.8 0.48 0.02sJ 0

Golf Course (2) I 80.00 80 2.82%, 3 Golf Course (3) 80 00 80 2.82% 3

Weighting Facton 1 I 1 I 1 1 - . . .. - . . - -

Proximity I Add. Trmt I Scuoml I Reliabilily I Total I i i

Under the 3 scenarios. I denotes the user targeted, 0 denotes the user not targeted. * * hlaximum Scenario also indude residential uxn.

I

Region 1, R o r t b Cirolinr

V a t e r U s e r s V a t e r S o u r c e s Golf C o u r s e s R o a d s H y d r o l o g y

Durham nble 4-8

Srfc yKld Avg. drily IEC

42 MOD 24.993 MOD I Weighting h a o n 1

Avg. drily dixbrtgc 20.3 MGD

Uldtr Ibc 3 Scenarios, I dcwtrr du mwr targeted, 0 dcrors b e mxr not trqcwd. " M r x i m m saarrio rlco includes rrridcatirl men.

Pelion J , Horth Carolina

l a t e r U s e r s 0 l a t e r S o u r c e s @ Golf C o u r s e s

, R o a d s H y d r o l o g y

Under the 3 sccturios, 1 denota he user largeled, 0 denotes the user not targeted. * * M8x~mum Mcnirio also indudes residcati8l uscn.

I

S e l e c t e d M a j o r W a t e r U s e r s QWASA

Pelion I , north Carolina

+ l a t e r U s e r s 0 l a t e r S o u r c e s @ Golf C o u r s e s

R o a d s &'J H y d r o l o g y

nble 4-10

Safe Yield 66.00 MGD Avg. daily use 3338 MGD Avg. daily discharge 29.79 MGD

Annual btiniated k of WW Ihen Class. Demand (MG) Non-Pot (MG) Flow

Ajinomoto ( I ) I 178.90 0.00% hfrllinckroat(2) I 178.90 R9.45 0.82%

Raleigh

Weighting Factors

0.40 0.20 0. IO 0.10 0.20 1.00 Water Reuse Sanarios

Minimum Proximity Additional Trmt Seasonal Reliability Water Use To Source Needed WaterUse ofDemand Tobl Mod. Agg. M u .

0.00 1 .00 2.00 3.00 0.00 0.70 0 0 0 1.00 0.00 2.00 2.00 2.00 1.20 0 1 1

Under the 3 scenarios, 1 d e w t a the user targeted, 0 denotes the user oot largekd. * * Maximum Saoarior also iaduda residential wen.

I S e l e c t e d M a j o r W a t e r U s e r s in. R a l e i g h

Tr i a n g l e J Council of G o v e r n m e n t s

W Petion I , North Carolina

$F F a t e r ' U s e r s 0 l a t e r S o u r c e s @ G o l f C o u r s e s

Roads

H y d r o l o g y

I

d

n n n u u u E H I

I S e l e c t e d M a j o r W a t e r U s e r s i n S a n f o r d

L

Triangle J Council of Governments -

Pelion I , Eortb C w o l i n r

l a t e r U s e r s l a t e r S o u r c e s

@ Golf C o u r s e s Roads

H y d r o l . o g y

nble 4-12

U s e n Johnston hlcniorial I losp. ( I ) Smithfield hfanor (2) Ilurlington ldustrics (3) 110 Jo Motor I d e e 14)

Smithfield I . , ' I

- -

Annual Estimated 46 of WW Minimum Proximity Class. Demand (MG) Non-Pot (MG) Flow Water Use To Source INS 26.057 7.8171 0.73% 1 2 R 6.722 2.0166 0.632 1 2 I 5.942 5.0507 0.sCSq 1 2 C 5.562 0.52scl 1 2

Safe Yield Avg. Daily Use Avg. daily discharge

Johnston Court AparL (7) Village Motor Ladgc (8) Magic Tunnel Car Wash (9) Golf Course 1

18 MGD 3.045 MGD 2.925 MGD

R 3.974 1.5896 0.37% 0 3 C 3.94 I 0.37% 0 3 C 2.566 0.24 % 0 3

m.00 80 7.49q 3 2

bmpc and Malphrus (5) II I 4.714 I I 0.44%( 01 2 Johnston Co. Courthouse (6) I INS I 4.381 I 0.419d 01 2

Weighting Facto I

0.1

Additional Tim1 Needed

3

3 2

3

3

0.1

Seasonal Water Use

2 2 2

of Demand

1.7 1 I 1.4

2 1.5

I

2 I 2.5

Water Rccae Scenarios

01 1 1 1 01 01 0 01 01 0

Under the 3 tccnarior, 1 denota the user targeted, 0 denotu the user not targeted. * * Maximum Sacaario also induda raidcntial wcra.

I

S e l e c t e d M a j o r W a t e r U s e r s

in Smithfield - . .

- T r i a n g l e J Council of Governments .-

I & l a t e r U s e r s l a t e r S o u r c e s

@ Golf C o u r s e s IM R o a d s

Q - @ W M Ittl

4.3.1 Discussion of Results

Carv The Town of Cary has 2 wastewater treatment facilities, located at the Northside and

Southside of the Town. The top 25 water users are characterized as commercial and

apartment complexes. Few users have high non-potable uses. There are also 3 golf courses.

The proposed Moderate Scenario targets golf course 1 and 2 only. The Aggressive Scenario

includes all three golf courses and the Raleigh Durham Airport. The Maximum Scenario

includes all residential users in addition to users included in the Aggressive Scenario. The

estimated reclaimed water demand for the Moderate, Aggressive, and Maximum scenarios are

160, 290, and 420 million gallons per year, respectively.

Durham

The City of Durham has three wastewater treatment plants, located in North and South side of

Durham and near Research Triangle Park. The top 30 water users are characterized as

industrial & institutional users. Six major users were identified as potential reclaimed water

users to be targeted based on the evaluation results and user survey. They are IBM, Duke

University, Harris Corporation, Microelectronic Center of North Carolina, Mitsubishi

Semiconductor, and the National Institute of Environmental Health Services. Most of these

top users are located within 5 miles of a wastewater treatment plant. There are also seven

golf courses. The Moderate Scenario proposed for Durham targets Golf course 1, 3, 5 6,

IBM, Duke University, and Harris Corporation. The proposed aggressive scenario targets all

the users under the Moderate Scenario, as well as Golf courses 2, 4, 7, Microelectronic Center

of North Carolina, Mitsubishi semiconductor, and the National Institute of Environmental

Health services. The proposed Maximum Scenario targets all residential users in addition to

all users under the Aggressive Scenario. The estimated reclaimed water demand under the

Moderate, Aggressive, and Maximum scenarios are 630, 1,070, and 2,570 million gallons per

year, respectively.

6512-1.2 4-13

OWASA

The OWASA system has one wastewater treatment facility. The major users in the system

are institutional (UNC-Chapel Hill) and apartment complexes. UNC-Chapel Hill has the

highest estimated non-potable water uses and the campus is located within 2 miles of the

wastewater treatment plant. There are also 2 golf courses in the service area. r

The proposed Moderate Scenario targets Golf course 1 and the UNC Power Plant. Targeted

users are extended to include the North Carolina Memorial Hospital chiller, the Northside and

Southside chillers on the UNC campus, and Golf course 2 in the Aggressive Scenario. The

Maximum Scenario includes residential users in addition to all users under the Aggressive

Scenario. The estimated reclaimed water demand for the three proposed scenarios are 220,

430, and 680 million gallons per year, respectively.

Raleigh

The City of Raleigh has one wastewater treatment facility located at the southeastern comer

of the city along Neuse River. The top ten users in this system are mostly institutional users,

including North Carolina State University, Wake Medical Center, and Rex Hospital. There

are also 9 golf courses in the City. All top users are located a considerable distance from the

wastewater treatment faci 1 i ty.

The proposed Moderate Scenario targets Golf courses 5, 7, and 8. The Aggressive Scenario

includes all nine golf courses, Mallincroat, and NC State University. The Maximum Scenario

includes all residential users in addition to all users under the Aggressive Scenario. The

estimated reclaimed water demand for the Moderate, Aggressive, and Maximum scenarios are

240, 880, and 2,670 million gallons per year, respectively.

Sanford

Sanford has one wastewater treatment facility. The top ten users are all characterized as

industrial. There is also 1 golf course. The proposed Moderate Scenario targets the golf

course. The Aggressive Scenario targets Sanford Finishing and Avondale Mills in addition to

the golf course. The Maximum Scenario includes all residential users in additional to all

6512-1.2 4-14

users in the Aggressive Scenario. The estimated reclaimed water demand for the Moderate,

Aggressive, and Maximum Scenarios are 80, 90, and 570 million gallons per year,

respective I y . -

Smithfield

Smithfield is served by a wastewater treatment facility operated by Johnston County. The

facility is located in Smithfield. Several major water u s e s in Smithfield are located within 3

miles of the wastewater treatment facility. These include the Johnston Memorial Hospital and

Burlington Industries. There is also one golf course.

The proposed Moderate Scenario targets the golf course. The Aggressive Scenario includes

the golf course, Johnston Memorial Hospital, and Burlington Industries. The Maximum

Scenario includes all residential users in addition to those included in the Aggressive

Scenario. The estimated reclaimed water demand for the Moderate, Aggressive and

Maximum Scenarios are SO, 90, and 160 million gallons per year, respectively.

6512-1.2 4-15

5.0 TECHNICAL AND ECONOMIC EVALUATION OF SCENARIOS

5.1 INTRODUCTION -

Building on the results of Section 4.0 this section presents the technical and eeonomic

evaluations that were performed on the selected water conservation and water reuse scenarios.

m e evaluations are based on a comparison of the estimated costs of implementing the

scenarios and on the savings in water use incurred from the conservation or reuse scenarios.

The analyses assumed implementation of scenarios would begin in 1993 and would be

completed in the year 2010. All economic analyses use a discount rate of 7.5 percent.

Evaluations have been performed considering the water conservation and water reuse

scenarios separately. This was done so that an independent determination of the cost-

effectiveness of water conservation and water reuse could be made. Realistically, however,

communities may want to consider implementing portions of both the water conservation and

water reuse scenarios concurrently. Conservation and reuse are complementary programs that

are both aimed at reducing the demand for potable water. Often, reuse is considered as one

component of a water conservation program. Concurrent implementation of water

conservation and water reuse scenarios should not impact the cost-effectiveness of either type

of program as long as the programs are planned together.

Section 5.2 presents the evaluation of the water conservation scenarios, and Section 5.3

presents the evaluation of the water reuse scenarios. Supplemental computations associated

with the evaluations are contained in Appendices A, B and C are referenced within the

sections following.

5.2 EVALUATION OF WATER CONSERVATION SCENARIOS

5.2.1 Considerations in Evaluation Procedure

The evaluation of the feasibility of the water conservation scenarios that were summarized in

Section 4.1 focused on the economic aspects of implementing the program. The technical

65 12-1.2 5- 1

feasibility of implementing all of the water conservation scenarios is presumed. The economic

evaluation consisted of estimating the costs and the savings accrued from implementing each of

the water conservation scenarios for each community. Descriptions of how the costs and savings

were estimated are given below. Comparisons of costs and savings are performed on an

equivalent annual basis over the 18 year planning period of this study (1993 to 2010) and are

reported in 1992 dollars. Because all values are given in 1992 dollars, no correction for inflation

is required.

Costs of implementing a water conservation program include the costs of the water conservation

measures as well as the loss in revenue that results from successfully reducing the amount of

water sold. This loss in revenues is partially offset by a reduction in operating costs of the

utility. However, there are fixed costs associated with operating a utility such as personnel costs

that usually do not change with changes in the flows of the water and wastewater facilities.

Therefore, utilities must usually increase water rates because the unit cost of supplying water has

increased. For the customer who conserves, however, the monthly bill for water and sewer

should stay the same or decrease a cost-effective program. The Customers who use the same

amount of water after implementation of the water conservation program will see an increase in

their monthly water and sewer bills.

Savings from a water conservation program are incurred from reductions on marginal operation

and maintenance costs of water supply facilities and by deferring capital expenditures that are

needed to expand water and wastewater facilities. Savings in operation and maintenance costs

come from areas such as reductions in the power costs associated with pumping within the plant

and in the distribution system and from reductions in the amount of chemicals needed for treating

a lower daily volume of water. Additional savings are incurred by deferring the expenditure of

capital costs for expanding water and wastewater facilities. When demands are reduced by a

water conservation program, the capacity of existing facilities will adequately meet demands for

a longer period of time (see Figure 5-1). Therefore, expansion of those facilities can be delayed

which saves money by delaying the time when capital expenditures must be made for the facility

expansion. Savings also result from not having to develop additional supply sources. These

65 12-1.2 5-2

I. , "

X

ILLUSTRATION OF DELAYING EXPANSION OF TREATMENT PLANT CAPACITY BY

REDUCING DEMAND WITH WATER CONSERVATION Fqum No.5-1

savings were not included quantitatively in this study because none of the communities

considered are projected to need a new water supply source within the year 2010 planning period.

A description of other potential benefitshavings from implementing a water conservation program

that were considered qualitatively is provided in Section 5.2.3.3. -

The following three sections describe the methodology that was used to estimate the costs of

implementing water conservation measures, the losses in revenue resulting from a water

conservation program, and the savings resulting from a water conservation program. Lastly, a

summary of all of these costs and savings is provided for each community which will be used

to project the overall impact of the water conservation program on the water and sewer rates and

the monthly bill of the individual customer.

5.2.2 Costs of Water Conservation Measures

Costs for the water consetvation measures were estimated based on conservation programs for

other comniunities and on estimated labor costs needed to implement the program. Labor costs

were assumed to be a constant $35,000 per person-year. General descriptions of the basis for

cost estimates of each of the water conservation measures follow.

Public Education -- costs were based on budgets of other communities with water

conservation programs and on estimated labor needs for the program.

New Building Codes -- because the new state building codes will go into effect in 1993,

it was assumed that there would be no costs to the utility above normal building

inspection costs unless additional plan review was needed to enforce more stringent

landscaping or metering requirements.

Retrofit Existing Development - costs were based on the estimated materials and

installation costs of retrofit devices such as low flow fixtures, toilet bags, and low flow

toilets.

65 12-1.2 5-3

e Leak Detection and Repair -- costs for leak detection were considered system maintenance

costs and were not attributed to the water conservation program.

-

C/I/I Water Audits -- costs were based on estimated labor costs to conduct water audits.

- . - :. Variable Rate Structures -- because most utilities will periodically update their rate

structures, it was assumed that this measure would require no additional costs to utility

above normal rate structure studies.

Water Use Ordinance -- no cost was assumed to the utility except for a maximum

program where regular enforcement may be necessary during drought conditions.

Tables showing the cost estimates for the three conservation scenarios for each community are

provided in Appendix A.

5.2.3 BenefitslSavinrs from Water Conservation Scenarios

Savings from implementing the water conservation scenarios for each community were estimated

based on savings in marginal costs of operating water supply facilities and savings from deferred

capital expenditures to expand water and wastewater facilities.

Note, however, that savings in operation and maintenance costs have not been found to occur for ML-I wastewater facilities as a result of a water conservation program. While the volumes of flow Fh$2

-/ may be reduced, the loadings of pollutants do not significantly change, Therefore, the costs h, - f(c6'?

associated with items such as chemicals and solids handling do not change. For this study, it is >a^J

assumed that no savings will incur from a reduction in flows to wastewater facilities. - Below are descriptions of the methodology used to calculate savings from the water conservation

scenarios for each community. Tables providing the intermediate calculations for each step of

the procedure are provided for each community in Appendix A. Summaries of the results of the

evaluations for each community are provided in Section 5.1.6.

65 12-1.2 5-4

5.2.3.1 Water Treatment Plant Savings

Savings in operation and maintenance costs were estimated by multiplying the expected reduction

in water demand by the marginal unit cost of water. Marginal unit costs of water were assumed

unless specific data for a jurisdiction was provided. The maximum reduction in water demand

was assumed to occur in the year 2010 with a linear reduction between the years 1993 and 2010.

n i s assumed that new development demands will increase linearly and that the retrofit program

will be implemented gradually over the planning period.

Savings in deferred capital costs were computed by first determining the year in which a plant

expansion would be needed with no conservation program and for each conservation scenario.

Demand projections used for this analysis were provided by Triangle J COG. Linear

interpolation or linear extrapolation was used to estimate the demands for years that specific data

was not provided. The peak treatment rate design factors were not assumed to change for the

different water conservation scenarios. Some reduction in peak demands may result from water

conservation measures such as water use ordinances; however, these savings are difficult to

quantify and so were not included. The plant expansion capacity was assumed to be the expected

growth in demand projected for 15 years past the expansion year. The same plant expansion

capacity was used for each conservation scenario. The cost of the plant expansion was assumed

to be $0.50 per gallon per day ($0.50 per gpd) of expansion capacity unless more specific plant

expansion costs were provided by the community. A present value was computed for the plant

expansion cost for each conservation scenario and was compared to the present value of the plant

expansion without a water conservation program. Because of the time value of money, plant

expansions that were deferred had a lower present value. The savings for each conservation

scenario was determined to be the difference in the present values of the future plant expansion

cost with and without the conservation program. Tables outlining these computations for each

community are provided in Appendix B.

5.2.3.2 Wastewater Treatment Plant Savings

Operation and maintenance costs were not projected to decrease significantly with a decrease in

water use from conservation. This is because many operation and maintenance costs are a

65 12-1.2 5-5

function of the waste loadings entering the plant. The solids loadings will - not change as a result __L_ ----

& -- of conservation measures.

/%.lc.=j .-d f3.9 ZLd

Savings from deferring capital costs of wastewater plant expansions were computed using the

same methodology as was used for computing savings from water treatment plant expansions.

ItIwas assumed that the percent reduction in wastewater flows would be equal to the percent

reduction in water use. This is not completely valid, however, because reductions in outdoor

water use do not result in reductions in wastewater flows. Projections in wastewater flows with

and without a water conservation program were used to estimate the year in which plant

expansions would be needed. The plant expansion capacity was assumed to be the expected

growth in demand projected for 15 years past the expansion year. The cost of the plant

expansion was estimated to be $1.65 per gpd of expansion capacity unless more specific

information was provided by the community. Tables outlining these computations for each

community are provided in Appendix B.

5.2.3.3 Other Benefits of a Water Conservation Program

Other benefitshavings may be obtained from a water conservation program that were considered

only qualitatively for this study. For example, the costs to develop a new water supply source

may also be deferred by a successful water conservation program. This may provide a significant

savings to the utility if implementing a source requires a major reservoir project. This aspect was

not considered for any of the communities in this study because none were in danger of

exceeding the safe yield of their source before the end of the study planning period, the year

2010. Because plans for developing new water supply sources in the study area are very

preliminary, it was not possible to develop reasonable estimates of the costs to develop those

sources. Water conservation may also provide benefits in deferring capital costs of water

distribution and wastewater collection systems. These savings were also not quantified in this

study.

F* + &,L.

,,f-L<

Another benefit that was considered qualitatively in this study is the potential for deferment of

using a lower quality raw water supply that may be more expensive to treat. For example, a

65 12- 1.2 5-6

successful water conservation program by OWASA may allow them to defer using Jordan Lake

as a raw water supply.

There are also environmental benefits from implementation of a water conservation program.

Water that is not drawn for water supply use will act to supplement the flow in rivers and

thereby further dilute wastewater discharges and improve downstream water quality. Increased

flows during typically dry periods of the year may also improve downstream aquatic habitat.

-

5.2.4 Loss in Revenues from Water Conservation

Loss in revenues from implementing water conservation were estimated using the water and

sewer revenues for each community for the year 1990 as obtained from the survey performed by

the North Carolina League of Municipalities (1990). Revenues were projected for the year 2010

by increasing the 1990 revenues in proportion to the projected increase in water demand. No

increase in rates was assumed. Revenue losses for the year 2010 were estimated by multiplying

the projected 2010 revenues by the estimated demand reduction (5%, 15%, 25%) for each

scenario.

Revenue losses were assumed to increase linearly over the 18 year planning period from 1993

to 2010. The present value of the estimated revenue losses was computed using an arithmetic

gradient series computation.

5.2.5 Impacts of Water Conservation on Customer Rates

The average percent increase in water rates was projected by adding the annual loss in revenues

to the annual costs of the water conservation program and subtracting the annual savings, and

dividing by the total annual revenues. This gives the average percent increase in water rates that

will be needed to cover fixed utility operating costs.

While customer rates increase, however, i t should be noted that the monthly water bill for the

average customer who conserves water may decrease. This would be because the amount of

water they use would decrease from conservation more than their water rates increase. The true

65 12-12 5-7

amount of change in a customer bill is difficult to predict, however, because of the uncertainty

in the true effectiveness in water conservation measures. Customers who do not conserve will

see an increase in their monthly water bill. -

5,2.6 Summarv of Evaluations for Individual Communities

This section contains tables that summarize the water conservation evaluations for each of the

five communities included in the conservation study. Supporting tables that provide more

detailed calculations of the savings and costs are included in Appendix A.

-

Tables 5-1 through 5-5 contain summaries of the evaluations that were performed for Cary,

OWASA, Raleigh, Sanford, and Smithfield, respectively. Row number 1 of these tables reiterates

the water reduction goals of 5, 15, and 25 percent that were assigned to the water conservation

scenarios. Row number 2 is the projected annual water use in the year 2010 for each

conservation scenario. Rows number 3, 4 and 5 show the estimated savings from implementing

the water conservation scenario. More detailed documentation of the savings calculations is

contained in the table in Appendix A, as referenced in the footnotes of the summary table for

each community. Row number 6 is the total estimated savings, which is the sum of row numbers

3, 4 and 5. Row number 7 is the equivalent annual savings over the 18 year planning period

with a discount rate of 7.5 percent. Supplemental calculations for the equivalent annual costs and

the annual loss of revenues of the water conservation scenario in row numbers 7 and 8 are also

provided in Appendix A. It should be noted that the equivalent annual savings calculation does

not accurately reflect the true method with which a treatment plant expansion would be financed.

The savings are spread across the 18 year planning period so that they can be compared to the

costs of implementing the conservation program which is assumed to occur over the 18 year

planning period of the study.

The average rate increase in row number 9 is computed by summing the equivalent annual costs

(row number 7) and the annual loss in revenues (row number S), subtracting the equivalent

annual savings (row number 6), and dividing by the total annual water and sewer revenues for

65 12-1.2 5-8

9

10 11

-

TABLE 5-1

SUMMARY OF FISCAL IMPACTS OF WATER CONSERVATION PROGRAM FOR THE

TOWN OF CARY

- -

Item Description Water Demand Reduction Goal 2010 ANNUAL WATER USE, MGD SAVINGS Deferred Water Facility Capital Water Treatment O&M Deferred Wastewater Capital TOTAL SAVINGS EQUIVALENT ANNUAL SAVINGS ANNUAL COSTS Water Conservation Program 2010 REVENUES w/o CONSERV. IMPACT TO CUSTOMER Average Unit Price Increase Average Change in Monthly Bill

Conservation Sc

5% 15% Moderate Aggressive

80,000 330,000 150,000 420,000 320.000 1,280,000

$550,000 $2,030,000 $57.000 $209.000

$18,000 $86,000 $1 1,022,000 $1 1,022,000

4.9 96 16.3% -0.3% -1.1%

enario Maximum

2,880,000

$457.000

$603.000 I

Notes *

* * * * * * 4

*

*

All dollars are given in 1992 $ Discount rate = 7.5% Row 3 from Table B-1 Row 4 from Table B-2 Row 5 from Table B-3 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (Alp, 7.596, 18) Row 8 from Table B-4 Row 9 from TabIe B-5 Row 10 = (Water Rate with Conservation / Water Rate without Conservation) - 1

Rate with Conservation = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Conservation = Row 9 / Demand without Conservation Demand without conservation from Table B-1

ROW 1 1 = ( 1 - R 0 ~ 1 ) * ( 1 + R 0 ~ 1 0 ) - 1

TABLE 5-2


ORANGE WATER AND SEWER AUTHORITY -

~ 7

Item Description Water Demand Reduction Goal 2010 ANNUAL WATER USE, Mc SAVINGS Deferred Water Facility Capital Water Treatment O&M Deferred Wastewater Capital TOTAL SAVINGS EQUIVALENT ANNUAL SAVIN ANNUAL COSTS Water Conservation Program

1 9 12010 REVENUES w/o CONSERV

* * * * * * * * * *

* *

IMPACT TO CUSTOMER

Notes All dollars are given in 1992 $ Discount rate = 7.5% Row 3 from Table B-6 Row 4 from Table B-7 Row 5 from Table B-8 Row 6 = Row 3 + Row 4 + Row 5

Conservation Scenario ~ -1 Moderate

5 % 10.45

10,000 230,000 190,000

$430,000 $44,000

Aggressive 15 %

9.35

70,000 640.000 520,000

$1,230,000 $127,000

$44.000 I $121,000 $12.833.000 I $12.833.000

5.3%1 17.6% 0.0% -0.0%

Maximum 1

620,000 1,070,000

650,000 $2 , 340 ,000

$806.000 $12,833,000

Row 7 = Row 6 * (Alp, 7.596, 18) Row 8 from Table B-9 Row 9 from Table B-IO Row 10 = (Water Rate with Conservation / Water Rate without Conservation) - 1

Rate with Conservation = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Conservation = Row 9 / Demand without Conservation Demand without Conservation from Table B-6

ROW 11 = (1 -ROW 1) * (1 +Row 10) - 1 Savings from delaying development of Jordon Lake as a water supply are not included -these savings could be significant and may increase the cost effectiveness of water

conservation for OWASA.

TABLE 5-3

- =

Row Item Description 1 Water Demand Reduction Goal 2 2010 ANNUAL WATER USE, MGD

SAVINGS 3 Deferred Water Facility Capital 4 Water Treatment O&M 5 Deferred Wastewater Capital 6 TOTAL SAVINGS 7 EQUIVALENT ANNUAL SAVINGS

ANNUAL COSTS 8 Water Conservation Program 9 2010 REVENUES w/o CONSERV.

IMPACT TO CUSTOMER 10 Average Unit Price Increase 1 1 Average Change in Monthly Bill


CITY OF RALEIGH

- -

Conservation Scenario Moderate Aggressive Maximum

5% 15 96 25 % 66.5 59.5 52.5

210,000 810,000 1,940,000 880,000 2,460,000 4,100,000

1 ,090,000 2,750 , 000 3,380,000 $2,180,000 $6,020,000 $9,420,000 $225 ,000 $620,000 $97 1 ,OOO

$20 1 ,000 $554,000 $3,671 ,000 $49,493,000 $49,493,000 $49,493,000

5.2% 17.5% 40.6% -0.1% -0.1% 5.5%

TABLE 5 4

Item Description Water Demand Reduction Goal 2010 ANNUAL WATER USE, MGD SAVINGS

Water Treatment O&M

TOTAL SAVINGS EQUIVALENT ANNUAL SAVINGS ANNUAL COSTS Water Conservation Program

Deferred Water Facility Capital

Deferred Wastewater Capital

SUMMARY OF FISCAL IMPACTS OF - WATER CONSERVATION PROGRAM FOR THE -

TOWN OF SANFORD

(

5% 7.9325

120,000 120,000 250,000

$490,000 $50,000

$6.000

Moderate L - Row

1 2

3 4 5 6 7

8 9

10 11

- - -

-

- -

-

Aggressive 15 %

* * * * * * * * *

*

Maxi mum 25 %

380,000 330,000 960,000

$1,670,000 $172,000

680,000 540,000

1,590,000 $2.8 10,000

$290,000

lonservation Scenario

$34,000 $8,093 ,OOO

15.6% -1.7%

$228 ,OOO $8,093 ,000

32.3% -0.8%

7.0975 I 6.2625

20 10 REVENUES w/o CONSERV. IMPACT TO CUSTOMER Average Unit Price Increase Average Change in Monthly Bill

$8,093 ,000

4.7% -0.5 %

All dollars are given in 1992 $ Discount rate = 7.5% Row 3 from Table B-16 Row 4 from Table B-17 Row 5 from Table B-18 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (A/P, 7.596, 18) Row 8 from Table B-19 Row 9 from Table B-20 Row 10 = (Water Rate with Conservation / Water Rate without Conservation) - 1

Rate with Conservation = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Conservation = Row 9 / Demand without Conservation Demand without Conservation from Table B- 16

ROW 11 = (1 -ROW 1) * (1 + ROW 10) - 1

TABLE 5-5

- kow Item Description

1 Water Demand Reduction Goal 2 2010 ANNUAL WATER USE, MGD

SAVINGS 3 Deferred Water Facility Capital 4 Water Treatment O&M 5 Deferred Wastewater Capital 6 TOTAL SAVINGS 7 EQUIVALENT ANNUAL SAVINGS

ANNUAL COSTS 8 Water Conservation Program 9 2010 REVENUES w/o CONSERV.

IMPACT TO CUSTOMER 10 Average Unit Price Increase 11 Average Change in Monthly Bill


5% 15% 25 % 4.18 3.74 3.3

70,000 310,000 530,000 60,000 170,000 290,000

130.000 490,000 720,000 $260,000 $970,000 $1,540,000 $27,000 $100,000 $159,000

$6,000 w,OOo $15 1 ,000 $5,636,951 $5,636,95 1 $5,636.95 1

4.9% 16.4% 33.1 % 4.396 -1.1% 4.2%

Notes * * * * * * * * * *

*

All dollars are given in 1992 $ Discount rate = 7.5% Row 3 from Table B-21 Row 4 from Table B-22 Row 5 from Table B-23 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (Alp, 7.5%, 18) Row 8 from Table B-24 Row 9 from Table B-25 Row 10 = (Water Rate with Conservation Water Rate without Conservation) - 1

Rate with Conservation = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Conservation = Row 9 / Demand without Conservation Demand without Conservation from Table B-2 1

ROW 11 = (1 - ROW 1) * (1 +ROW 10) - 1

the utility. The total annual revenues were obtained from the survey of water and sewer rates

that was conducted by the North Carolina League of Municipalities (1990).

- The average rate increase will cover fixed costs such as personnel costs and administrative costs

that do not change based on the amount of water sold. Because the fixed costs do not decrease

*en the amount of water sold decreases, water rates must increase to cover these costs. -

Row number 10 shows the average change in the monthly bill of a customer who reduces water

usage by the same amount as the water reduction goal for that scenario (see row number 1).

Note that these computations assume that the water reduction goals of each scenario are met.

The estimated water reductions for the water conservation scenarios each were given a range of

uncertainty (see Appendix A) that reflects the limited and varied results of water conservation

programs around the country.

5.3 EVALUATION OF WATER REUSE SCENARIOS

5.3.1 Considerations in Evaluation Procedure

The potential value of reclaimed water depends primarily on its assured availability and on its

costs as compared to the cost of freshwater. In conducting the economic evaluation, the costs

in implementing water reuse, the benefits and savings, and other economic impacts such as loss

in water sales revenue due to a reduction of freshwater consumption and potential impacts on

user rates were considered.

5.3.2 Costs for Implementation

The costs for implementing the water reuse scenarios may include:

costs for additional treatment, if required

costs for conveyance/distribution of the treated effluent

65 12-1.2 5-1 4

costs for storage, if necessary.

All of the wastewater treatment facilities in the six systems under study provide adequate level

of treatment for reuse except the Northside Plant of Cary, which would require the addition of

filtration facility. The cost of additional treatment was estimated by using EPA cost curves. No

additional treatment costs were included for the other systems.

In estimating the conveyaneldistribution costs for the Moderate and Aggressive scenarios in each

system, the sizes of the reuse main and pumping stations were calculated based on the projected

reclaimed water demand and the location of the users. Again, EPA cost curves were used to

estimate the costs of the conveyance/distribution system. Under the Moderate and Aggressive

scenarios, only specific users were targeted, and these users were either golf courses, institutional

or industrial users. It was assumed that most golf courses and industriaI/institutional users would

provide their own storage, and the costs for storage were not considered under the Moderate and

Aggressive scenarios.

Under all the Maximum reuse scenarios, a complete reclaimed water distribution system would

be required to serve all the residential users. To estimate the costs for the Maximum scenarios,

the 1990 Census data were used to calculate the number of equivalent residential units (ERU)

in each system. A growth factor obtained by the project increase in water demand was then

applied to estimate the number of ERU in 2010. From existing dual water systems across the

country i t was observed that the capital cost of dual water distribution system range from $1200 - $1700 per ERU. These costs include conveyance/distribution as well as system storage. A

capital cost of $15OO/ERU was selected for the cost estimate. This figure compared well with

some of the water system’s new hook-up charges. The annual operational and maintenance costs

for the dual distribution system was assumed to be $0.10 per 1000 gallons. An example of this

costs analysis is shown in Table 5-6. Tables 5-7 to 5-12 summarize the estimated costs of

implementing a moderate, agressive and maximum reuse program for the six water systems. A11

costs were estimated on an annual basis, with capital costs amortized over a 18 year period at

a rate of 7.5%.

6512-1.2 5-1 5

Table 5-6

Avg. Water Demand (mgd) 7.53

WATER DEMAND (GPCD) 250.5 Population Served 30054

I# CAPITAERU 2.18 WATER DEMANDERU (GPD) 546.2 % OUTDOOR USE 19.0% RECL. WATER DEMANDERU (GPD) 103.8 No. of ERU 13786.2 Total Reclaimed Water (mgd) 1.4 COSTERU $1,500 Capital cost ($) $20,680,000 M O R T . CAP $2,130,000 DELIVERY SYS. 06rM ($/I000 GAL) 0.1 ANNUAL O&M COST $50,000 Total Cost $2,180,000

SYSTEM= SCENARIO= USER=

OWASA MAXIMUM RESIDENTIAL

Notes: * *

Population data obtained from 1990 Census. % outdoor use estimated from flow and rainfall data provided by TJCOG.

Table 5-7 ESTIMATED COSTS FOR WATER REUSE PROGRAMS

Reclaimed Water ($)

Total Cost ($) Cost per 1000 gal of reuse ($)

Estimated Net Revenue Loss ($/yr) 1 '10,000 200,000 440,000

200,000 4 10,000 3,3 10,000 1.25 1.43 5.21

(1 1 0,000) (1 30,000) 1 10,000

Notes: Capital costs include pumping & distribution system, no additional treatment cost is included. System storage cost is included under the maximum scenario. For the Moderate and Aggressive scenarios, it is assumed that storage will be provided by the specific user(s). Amortization is over a 18 year period at an interest rate of 7.5%. Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. Potable water cost is calculated by reported system revenue divided by system consumption (NCLM,1991).


Reclaimed Water ($) Estimated Net Revenue Loss ($/yr) Total Cost ($) Cost per 1000 gal of reuse ($)

400,000 680,000 2,740,000 0 (40,000) 2,040,000

660,000 1,390,000 12,) 60,000 1.04 1.30 2.81

Notes: * Capital costs include pumping & distribution system, no additional treatment cost

is included. * System storage cost is included under the maximum scenario. * For the Moderate and Aggressive scenarios, it is assumed that storage will be provided

by the specific user(s). * Amortization is over a 18 year period at an interest rate of 7.5%. * Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. * Potable water cost is calculated by reported system revenue divided by system

consumption (N CLM, 1 99 1).


OWASA

Total Annual Cost

Notes: Capital costs include pumping & distribution system, no additional treatment cost is included. System storage cost is included under the maximum scenario. For the Moderate and Aggressive scenarios, it is assumed that storage will be provided by the specific user@). Amortization is over a 18 year period at an interest rate of 7.5%. Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. Potable water cost is calculated by reported system revenue divided by system consumption (N CLM, 199 1).


RALEIGH

~~

Notes: Capital costs include pumping & distribution system, no additional treatment cost is included. System storage cost is included under the maximum scenario. For the Moderate and Aggressive scenarios, it is assumed that storage will be provided by the specific user(s). Amortization is over a 18 year period at an interest rate of 7.5%. Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. Potable water cost is calculated by reported system revenue divided by system consumption (NCLM,1991).

SANFORD

Capital cost (S) Amortized capital ($) Annual O&M cost ($) Total Annual Cost ($) Estimated Reuse Volume (MG/yr) Estimated Reduction in Fresh water Demand (MG/yr) Estimated Revenue Loss ($) Estimated Revenue from Reclaimed Water ($) Estimated Net Revenue Loss ($/yr)

Table 5-1 1 ESTIMATED CQS'IS FOR WATER REUSE PROGRAMS

Moderate 1,140,000 120,000 10,000 130,000

80

0 0

70,000 (70,000

- I Water Reuse Scenarios

Aggressive 2,160,OOO 220,000 30,000

250.000

Maximum 10,750,OOO 1,110,Ooo

80,000 1.1 90.000

Total Cost ($) Cost per 1000 gal of reuse ($)

Notes:

60,000 0.75

I

169 I 1.223

150,000 1,090,000

Capital costs include pumping & distribution system, no additional treatment cost is included. System storage cost is included under the maximum scenario. For the Moderate and Aggressive scenarios, it is assumed that storage will be provided by the specific user(s). Amortization is over a 18 year period at an interest rate of 7.5%. Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. Potable water cost is calculated by reported system revenue divided by system consumption (NCLM, 1991).


Reclaimed Water ($) Estimated Net Revenue Loss (S/yr) Total Cost ($) Cost per 1000 gal of reuse ($)

SMITHFIELD

80,000 90,000 190,000 (80,000) (60,000) 40,000 1 0,000 90,000 710,000

0.13 0.97 3.62

Notes: Capital costs include pumping & distribution system, no additional treatment cost is included. System storage cost is included under the maximum scenario. For the Moderate and Aggressive scenarios, it is assumed that storage will be provided by the specific user@). Amortization is over a 18 year period at an interest rate of 7.5%. Estimated revenue from reclaimed water is assumed to be 50% of potable water cost. Potable water cost is calculated by reported system revenue divided by system consumption (NCLM,1991).

5.3.3 BenefitslSavinrs

Having developed the costs of reclaimed water it is evident that they are not lower than those

of freshwater. However, there are other factors that need to be taken into account in the

eva 1 ua t ion. -

Reduction in freshwater use - .

The use of reclaimed water can no doubt offset some of the non-potable demand on freshwater.

This reduction can have several benefits, including savings in water treatment costs and deferred

capital costs in future plant expansion. The savings in operation and maintenance costs are

estimated by multiplying the expected reduction in water demand by the marginal unit cost of

water. Marginal unit costs of water are assumed unless specific data for each system are

provided.

. The savings in deferred capital costs were computed by first determining the year in which a

plant expansion is needed for each scenario. The plant expansion capacity was assumed to be

the expected growth in demand projected for 15 years past the expansion year. A present value

was computed for the plant expansion cost and compared to the present value of the plant

expansion without a water reuse program. The savings is the difference in the present values of

the plant expansion with or without a reuse program. The equivalent annual savings was

computed for the planning period of 18 years at a discount rate of 7.5 percent. As discussed in

Section 5.2.3.1, the cost of water treatment plant expansion was assumed to be $0.50 per million

gallons per day ($0.50 per mgd) of expansion capacity unless more specific plant expansion costs

were provided.

0 Delay in the search for a new water source

With the reduction in freshwater use, there may be a delay in the need for a new water source.

All of the systems in this study except Raleigh will not reach the safe yield of their water supply

65 12-1.2 5-23

at 2010. The magnitude of this benefit will no doubt vary according to the availability of

freshwater supply, and the current demand and growth rate versus safe yield.

- 0 Reduction of wastewater effluent discharges

f i e reuse of wastewater effluent could reduce the amount of discharge to receiving streams

substantially. This can be a major benefit in the Triangle J Region where stream allocations have

reached or exceeded assimilative capacity. For future growth in the Region, it is doubtful if

existing streams can accommodate additional wastewater effluent. As in other parts of the

Country reuse may be the most cost effective means of expanding treatment capacity, unless

alternative discharge points can be located. At a minimum, reuse of the wastewater plant effluent

would delay the time when discharges reach the permitted limits. An estimate of this time delay

is presented in Tables 5-13 to 5-18. I t would be difficult to quantify this benefit in dollars as

this varies from system to system and depends on many other factors that are not yet determined.

5.3.4 Revenue Loss

From the water utilities’ perspective, the reduction in water consumption also results in a

reduction of water sales revenue. Although revenue can also be recovered from the sale of

reclaimed water, i t is unsure if reclaimed water can be sold at the price of freshwater. Since

reclaimed water cannot be distributed through the existing water distribution system, a separate

capital and operational and maintenance costs could be incurred and the sale of reclaimed water

can only be hoped to recover some of these costs. For estimating purposes, it can be assumed

that reclaimed water can be sold at 50% of the cost for freshwater. Estimated revenue from

reclaimed water sales and the corresponding reduction in water sales revenue are shown in Tables

5-7 to 5-12.

5.3.5 Immct o n User Rates

The costs and potential revenue impacts for implementing each of the reuse scenario have been

presented. There are many financing options for water reuse programs including funding from

the existing operating budget, property taxes, special assessments and existing user charges. A

6512-1.2 5-24

Without Reuse -

Avg Max Day Mon

Flows in Year 1990 5.2 7.8 Flows in Year 1993 5.8 8.7 Flows in Year 2010 9.1 13.7

Maximum Month Design Factor 1.5 Existing Treatment Capacity 10.4 Year Plant Reach Effluent 1998.9 Discharge Limit

With Reuse (reduction in mgd) Moderate Aggressive Maximum

Avg Max Avg Max Avg Max Day Mon Day Mon Day Mon

( e 4 1 (0.8) (1.2)

5.2 7.8 5.2 7.8 5.2 7.8 5.8 8.7 5.8 8.7 5.8 8.7 8.7 13.1 8.3 12.5 7.9 11.9

1.5 1.5 1.5 10.4 10.4 10.4

1999.7 2000.8 2002.2

Table 5-14 ESTIMATED TIME DELAY T O REACH EFFLUENT DISCHARGE CAPACITY

WASTEWATER TREATMENT PLANT -

(all flows in mgd) - DURHAM

1 Without

Flows in Year 1990

With Reuse (% reduction) Moderate I Aggressive I Maximum

I FIOWS in Year 1995

(2.9 MGD) Avg I Max

Flows in Year 201 0 Maximum Month Design Factor Existing Treatment Capacity Year Plant Expansion Needed

(7.0 MGD) Avg I Max

Day 20.3

I Reuse I (1.7MGD)

Mon Day Mon 30.5 20.3 30.5

Avg I Max I Avg I Max Day 20.3

Mon Day Mon 30.5 20.3 30.5

27.2 45.1

40.8 27.2 40.8 67.7 41.0 61.5

1.5 1.5

27.2 48.0

40.8 27.2 40.8 72.0 46.3 69.5

1.5 46

1997.48

1.5 46

1997.705 46

1997.88 46

1998.74

Table 5-15 ESTIMATED TIME DELAY TO REACH EFFLUENT DISCHARGE CAPACITY

WASTEWATER TREATMENT PLANT (all flows in mgd)

OWASA

Flows in Year 1990 I FIOWS in Year 1995

Flows in Year 201 0 Maximum Month Desirn Factor

Y

Existing Treatment Capacity Year Plant Expansion Needed

Without Reuse

14.3 1.5 12

2002.29

With Reuse ( Moderate

(.6 MGD)

8.9 13.4 1.5 12

2004.181

- c

~

Ib reduction) I Aggressive Maximum (1.2 MGD) (1.9 MGD)

Day Mon Day Mon 5.6 8.4 5.6 8.4 6.6 8.3 1 12.5 9.9 I 6: 1 11.4 9.9 I

1.5 I 1.5 I 12 I 12 I

2007.38 I 2015.88 I

- With Reuse (% reduction)

_ . - Without Moderate Aggressive Maximum - . Reuse (.7 MGD) (2.4 MGD) (7.3 MGD)

Avg Max Avg Max Avg Max Avg Max . Day Mon Day Mon Day Mon Day Mon

Flows in Year 1990 29.8 44.7 29.8 44.7 29.8 44.7 29.8 44.7 Flows in Year 1995 36.2 54.2 36.2 54.2 36.2 54.2 36.2 54.2 Flows in Year 2010 55.2 82.8 54.5 81.8 52.8 79.2 47.9 71.9

Maximum Month Design Factor 1.5 1.5 1.5 1.5

Year Plant Expansion Needed 2029.53 2030.848 2034.50 2050.99 Existing Treatment Capacity 120 120 120 120

Table 5-17 ESTlMATED TIME DELAY TO REACH EFFLUENT DISCHARGE CAPACITY

WASTEWATER TREATMENT PLANT

- (all flows in mgd)

Maximum Month Design Factor Ex is t ing Treatment Capacity Year Plant ExDansion Needed

SANF’ORD

Flows in Year 1990 Flows in Year 1995 Flows in Year 201 0

Without Reuse

1.5 6.8

2004.50

With Reuse ( Moderate (.2 MGD)

Mon 3.3 5.0 3.7 5.6 4.8 7.2

1.5 6.8

2006.273

k reduction) I Aggressive Maximum (.2 MGD) (1.6 MGD)

Avg I Max I Avg I Max I Day Mon Day Mon

3.3 5.0 3.3 5.0

6.8 I 6.8 I 2006.27 I 1957.95 I

SMITHFIEIl) _ .

Without Reuse

Avg Max Day Mon

2.9 4.4 3.2 4.8 4.2 6.3

1.5 4

1986.36

Table 5- 18 ESTIMATED TIME DELAY TO REACH EFFLUENT DISCHARGE CAPACITY

WASTEWATER TREATMENT PLANT (all flows in mgd) -

With Reuse Moderate

(.2 MGD) Avg Max Day Mon

2.9 4.4 3.2 4.8 4.0 6.0

1.5 4

1984.137

Flows in Year 1990 Flows in Year 1995 Flows in Year 201 0

Maximum Month Design Factor Existing Treatment Capacity Year Plant Expansion Needed

Aggressive (.3 MGD)

Avg Max Day Mon

2.9 4.4 3.2 4.8 3.9 5.9

1.5

Maximum (.5 MGD)

Avg Max Day Mon

2.9 4.4 3.2 4.8 3.7 5.6

1.5

1982.52 I 1977.25 1

detailed discussion of these options is beyond the scope of this study. Depending on the

financing options chosen, the user rates may or may not be impacted significantly. Users can

expect rising costs of water treatment and wastewater disposaI/reuse as we strive to improve

treatment standards and environmental qualities. Tables 5-19 to 5-24 summarize the fiscal

impacts of the water reuse programs for each system.

65 12-1.2 5-25

Row IItem Description Moderate 0

3942

TABLE 5-19

- SUMMARY OF FISCAL IMPACTS OF WATER REUSE PROGRAM FOR THE

TOWNOFCARY

Aggressive Maximum 47 227

3895 371 5

I

1 IWater Demand Reduction (MG/vr)

0 0 0

$0 $0

2 12010 ANNUAL WATER USE, MG

10,000 50,000 30,000 140,000

0 0 $40,000 $1 90,000 $4,000 $20,000

3 4 5 6 7

8 9

10

-

- -

$200,000 $5,490,000

SAVINGS Deferred Water Facility Capital Water Treatment O&M Deferred Wastewater Capital TOTAL SAVINGS EQUIVALENT ANNUAL SAVINGS ANNUAL COSTS Water Reuse Program 2010 REVENUES w/o REUSE I M P A n TO CUSTOMER Average Unit Price Increase

$360,000 $3,310,000 $5,490,000 $5,490,000

dotes

Reuse Scenario I

3.64 7.84 69.771

* Discount rate = 7.5%

*

All dollars are given in 1992 $

Row 3 from Table C-1 Row 4 from Table C-2 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (AP, 7.5%, IS) Row 8 from Table 5-7 2010 Revenues projected using the same factor as water demand increase Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1

*

* * * * Rate with Reuse = (Row 9 + Row 8 - Row 7) / Row 2

Rate without reuse = Row 9 Demand without Reuse Demand without Reuse from Table C-1

TABLE 5-20

1 2

SUMMARY OF FISCAL IMPACTS OF WATER REUSE PROGRAM FOR THE

CITY OF DURHAM

Water Demand Reduction (MG/yr) 2010 ANNUAL WATER USE, MG

31 5 13409

I Reuse Scenario

3 4 5 6 7

Row lltem Description I Moderate

SAVINGS Deferred Water Facility Capital Water Treatment O&M Deferred Wastewater Capital TOTALSAVINGS EQUIVALENT ANNUAL SAVINGS

640,000

$1,370,000

8 9

ANNUAL COSTS Water Reuse Program $660,000 2010 REVENUES w/o REUSE $1 7,330,000 IMPACT TO CUSTOMER

10 Average Unit Price Increase 1 5.4% 131.6% 11.2%l ~ ~~

Notes * * Discount rate = 7.5% * * * * * * *


Row 3 from Table C-3 Row 4 from Table C-4 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * ( N P , 7.5%, IS) Row 8 from Table 5-8 2010 Revenues projected using the same factor as water demand increase Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1

Rate with Reuse = (Row 9 + Row 8 - Row 7) /Row 2 Rate without Reuse = Row 9 /Demand without Reuse Demand without Reuse from Table C-3

TABLE 5-21

8 9

10

Water Reuse Program $240,000 $470,000 $4,140,000 2010 REVENUES w/o REUSE $12,9 10,000 $12,910,000 $ 12,910,000 IMPACT TO CUSTOMER Average Unit Price Increase 6.6% 14.2% 128.0%

Notes * * Discount rate = 7.5%

*


Row 3 from Table C-5 Row 4 from Table C-6 Row 6 = Row 3 + Row 4 + Row 5

Row 8 from Table 5-9 2010 Revenues projected using the same factor as water demand increase

*

* * Row 7 = Row 6 * (AP, 7.5%, 18) * * * Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1


TABLE 5-22

Row 1 2

8 9

10


CITY OF W I G H

Deferred Water Facility Capital Water Treatment O&M Deferred Wastewater Capital TOTAL SAVINGS

Average Unit Price Increase

Notes * All dollars are given in 1992 $

Discount rate = 7.5% Row 3 from Table C-7 Row 4 from Table C-8 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (AP, 7.5%, 18) Row 8 from Table 5-10 2010 Revenues projected using the same factor as water demand increase Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1

* * * * *

* *

Rate with Reuse = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Reuse = Row 9 /Demand without Reuse Demand without Reuse from Table C-7

TABLE 5-23 -

Row Item Description 1 Water Demand Reduction (MG/yr) 2 2010 ANNUAL WATER USE, MG

SAVINGS 3 Deferred Water Facility Capital 4 Water Treatment 0 & M

6 TOTALSAVINGS 5 Deferred Wastewater Capital

- SUMMARY OF FISCAL IMPACTS O F WATER REUSE PROGRAM FOR THE

TOWN OF SANFORD

Reuse Scenario Moderate Aggressive Maximum

0 89 1143 3066 2977 1923

0 0 41 0,000 0 0 860,000 0 0 0 $0 $0 $1,270,000

7 EQUIVALENT ANNUAL SAVINGS $0 $0 $131,000 ANNUAL COSTS

8 9

10

Notes * * Discount rate = 7.5% * *


Row 3 from Table C-9 Row 4 from Table C-10 ROW 6 = Row 3 + Row 4 + Row 5 ROW 7 = Row 6 * (AP, 7.5%, 18) Row 8 from Table 5-1 1 2010 Revenues projected using the same factor as water demand increase Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1

* * * * *

Rate with Reuse = (Row 9 + Row 8 - Row 7) / Row 2 Rate without Reuse = Row 9 /Demand without Reuse Demand without Reuse from Table C-9

Water Reuse Program $60,000 $260,000 $2,130,000 2010 REVENUES w/o REUSE $5,400,000 $5,400,000 $5,400,000 IMPACT T O CUSTOMER Average Unit Price Increase 1.1% 7.9% 11 8.5%

TABLE 5-24 -

Row Item Description 1 Water Demand Reduction (MG/yr) 2 2010 ANNUAL WATER USE, MG

SAVINGS


TOWN OF SMITHFIEIB

Reuse Scenario Moderate Aggressive Maximum

0 13 116 1314 1301 1198

Deferred Water Facility Capital Water Treatment O&M

TOTAL SAVINGS EQUIVALENT ANNUAL SAVINGS ANNUAL COSTS Water Reuse Program 2010 REVENUES w/o REUSE IMPACT TO CUSTOMER Average Unit Price Increase

Deferred Wastewater Capital

3 4 5 6 7

8 9

10

0 0 70,000 0 0 860,000 0 0 0 $0 $0 $930,000 $0 SO $96,000

$10,000 $90,000 $710,000 $8 30,000 $ 8 30,000 $830,000

1.2% 12.0% 90.8%

Notes * All dollars are given in 1992 $

Discount rate = 7.5% Row 3 from Table C-11 Row 4 from Table C-12 Row 6 = Row 3 + Row 4 + Row 5 Row 7 = Row 6 * (AP, 7.5%,18) Row 8 from Table 5-12 2010 Revenues projected using the same factor as water demand increase Row 10 = (Water Rate with Reuse /Water Rate without Reuse) - 1

* * * * * * * *


6.0 CONCLUSIONS AND -RECOMMENDATIONS

6.1 WATER CONSERVATION - The evaluation of the water conservation scenarios presented in Section 5.2 indicate that there

isla good potential for savings to water utilities that implement water conservation programs.

The evaluation showed that all communities included in the water conservation study could

have a net positive benefit by implementing a moderate or aggressive water conservation

program. Based on the estimated costs of the moderate and aggressive programs and the

assumptions that the water reduction goals are met, the evaluation showed that the average

monthly bill for a customer who practices water conservation will decrease.

The most significant potential savings from water conservation for most communities in this

study was the ability of the water conservation program to allow deferment of wastewater

treatment plant expansions. A water conservation program is predicted to decrease the

hydraulic loading of a wastewater treatment plant, but it will not reduce the pollutant loadings

entering the plant. It is expected that existing plants would be able to handle increased

pollutant loadings without needing expansion because of the design factors that are typically

built-in to wastewater treatment plant designs. Therefore, the wastewater treatment plant

expansion could be deferred until the hydraulic capacity is exceeded, thereby resulting in

savings in financing costs of the plant expansion. These potential savings may even be

greater than predicted because this study only considered the costs of expanding the existing

plant at its present location. The cost of expanding wastewater treatment capacity may be

much higher if the wasteload allocation of an existing stream is reached and a new location is

needed or a more sophisticated treatment process is needed. This may be the case for several

communities in the Triangle J Region. If the cost of expanding wastewater treatment capacity

is higher, then the potential savings from deferring an expansion with a water conservation

program would also be higher.

The water reduction goals of 5, 15, and 25 percent were set for the moderate, aggressive, and

maximum scenarios to reflect the range of potential reductions that may be targeted by

6512-1.2 6-1

Triangle communities and the water reductions achieved in other communities. The water

conservation scenarios for each study community were designed to meet the water reduction

goals; however, the uncertainty in the reductions that may be achieved from specific measures

makes the overall reductions difficult to predict. However, the water reduction estimates have

pmvided insight as to the relative potential benefits from the water conservation measures for

the study communities.

Significant water reductions are expected by the year 2010 as a result of the revisions in the

North Carolina plumbing code that will become effective January 1, 1993. Several

communities that are expecting continued rapid growth through year 2010 will benefit from

the low-flow fixtures and toilets that will be required in new development. These

communities should consider implementation of additional development regulations, such as

water-conserving landscaping (xeriscaping) requirements that will further exploit the benefits

of reducing the water needs of new development.

From the evaluations presented in Section 5 and the estimated water reductions presented in

Appendix A, i t appears that the water use reduction goal of 25 percent will be very expensive

and very difficult to meet. It is not likely that this water reduction could be achieved in a

"water rich" region such as the Triangle except under critical drought conditions where

citizens felt the impending possibility of running out of water. I t is not recommended that

any communities attempt to implement a maximum program.

There are additional benefits of implementing water conservation programs for some

communities that were not addressed quantitatively in this study. For example, a water

conservation program may allow the Orange Water and Sewer Authority (OWASA) to delay

use of Jordan Lake as an additional water supply. The costs of implementing Jordan Lake as

a water supply source for OWASA will be significant and will include costs to construct a

pipeline, pump station, additional treatment capacity, and costs to receive water supply pool

allocation from the U.S. Corps of Engineers. Delaying these costs could result in a

significant savings to OWASA and therefore provide additional justification for OWASA to

65 13- 1.2 6-2

implement a water conservation program. Other benefits of a water conservation program

include the ability to maximize the use of a high quality water supply, and the environmental

benefits of withdrawing less water from the raw water supply. - -

Based on the evaluation performed in this study, the following are recommended.

0 Begin implementing moderate water conservation programs in all communities

consisting of, at a minimum, a public education program and an emergency water

shortage plan. Triangle J COG should become involved in encouraging communities

to consider water conservation as a cost-effective measure for any public utility.

Implement a regional public education program for water conservation that would be

funded by contributions from the water utilities included in the region. Contributions

should be proportionate to the number of customers served by each utility. The public

education program should consist of developing water conservation brochures and

billing inserts discussing the benefits of water conservation even in a water-rich state

such as North Carolina.

Implement a pilot program to better estimate the water reductions from an aggressive

water conservation program. The pilot program should include retrofit of existing

development with low-flow fixtures and reduced-volume toilet flush kits and a more

focused public education program. Additional public education measures could

include scheduled presentations to homeowners associations or other local civic

groups. A pilot program will assist in reducing the uncertainty in the water reduction

goals that can be reasonably achieved in the Triangle J area. A monitoring program

should be incorporated into the pilot study to determine effectiveness of the water

conservation measures in the pilot area. The pilot program will better identify the

water use reductions that may be obtained locally for the water conservation measures

discussed in this report.

7 &L

P4

6512-1.2 6-3

6.2 WATER REUSE Evaluations carried out in Section 3 suggest that if non-potable demands could be addressed

by reclaimed water, potable water use could be reduced by up to 20% on an average annual

basis. In peak season (June and July) average monthly potable water demand-reductions

could be on the order of 30%. Maximum month water conservation may approach 45%

depending on the specific meteorologic conditions. From a technological standpoint numerous

examples of successful water reuse have been developed throughout the United States,

although to date these programs tend to be centered in states that have experienced prolonged

droughts or where the ability to discharge wastewater as a means of disposal has been

limited. Such programs range from the irrigation of non-edible agricultural crops to the

irrigation of single family homes, parks and playgrounds, as well as groundwater recharge

programs providing augmentation to sources of potable water. At this time, the North

Carolina regulations on reuse only address a restricted use on golf courses and/or large turf

sites in an urban setting. I t is expected that close coordination with the regulators would be

required in order to expand on the current regulations and take advantage of other reuse

opportunities.

As shown in Section 5, the development of a dual distribution system may be quite expensive

and, when compared to the cost of expanding water treatment facilities, not justifiable.

However, this may change radically when and if a municipality faces the need to develop a

new source of raw water as opposed to the simple expansion of water treatment facilities.

The economics of reuse may also be enhanced as the wasteload allocations of regional water

bodies are exceeded and a diversion of effluent from these water bodies is required by law.

It appears that some form of water reclamation will be needed in the future. In order to

facilitate this action the following steps should be considered at this time:

Development of comprehensive water reclamation and reuse regulations, policies,

and/or guidelines. These should include provisions for the irrigation of single family

homes as well as other industrial and commercial uses of reclaimed water.

65 12-1.2 6-4

0 Based on the findings of the water use invcntory given in Section 4, a wide variety of

potential reuse customers are available. In many cases the reclaimed water quality

required by these customers may be less than that currently required far surface water

discharge. In current reuse programs some wastewater treatment plants have been

designed for intermittent AWT treatment (for surface water discharge) or the

production of filtered secondary effluent without nutrient removal (for reuse

applications). Such provisions may also be worthwhile in considering future designs

in the Triangle J service area.

I

5

0 Experience has shown that implementation of a dual distribution system is always less

costly if planned into the original construction of a given site. As such, municipalities

may wish to review proposed development in and around existing treatment facilities.

Likely customes should include all of those use categories identified in Section 4.0, in

order to provide institutional support for such programs. Ordinances should be

researched and enacted allowing the municipality to require reuse where it is

determined to be a cost effective means of providing a non- potable water service.

Communities facing water shortage problems or wastewater discharge limitations

should consider implementing moderate or aggressive reuse scenarios. As shown in

Section 5.0, the costs of implementing these two scenarios are not prohibitive.

Implementation of at least a moderate program would help to lay the framework for

more extensive reuse in the future.

6513-1.2 6-5

7.0 REFERENCES

Camp Dresser & McKee, Water Conservation Plan for the City of Venice Florida, - March 1989.

a m p Dresser & McKee, Residential Reuse Master Plan for the City of Venice Florida, March 1990.

Camp Dresser & McKee, National Survey of Costs to Construct and Expand Wastewater Treatment Facilities, unpublished to date.

Consumer Reports Magazine, "How to Save Water;" July 1990.

Denver Water Department, Water Conservation Plan (1986 Update of a Plan adopted June 20, 1979), 1989.

Rack, J.E. and J. Greenberg, "Public Attitudes Toward Water Conservation," J. of the American Water Works Association, March 1987.

Holland, E., Research and Planning Administrator, Orange Water and Sewer Authority. Facsimile transmittals dated March 29, 1992 and July 31, 1992.

Maddaus, William O., Water Conservation. American Water Works Association, 1987.

Mann, P.C. and D.L. Schlenger, "Marginal Cost and Seasonal Pricing of Water Service," the American Water Works Association, January 1982.

Moreau, David H., Water Conservation in Durham: Economic and Financial Impacts of Selected Programs. Water Resources Research Institute of the University of North Carolina, July 1991.

Morgan, W. D. and P. Pelosi, "The Effects of Water Conservation Kits on Water Use. JAJ' the American Water Works Association, March 1990.

North Carolina League of Municipalities, How Much Does Clean Water Cost? Results of the 1990 NCLM Water and Sewer Rates and Services Survey of North Carolina Municipalities. January 1991.

Renshaw, E.F., "Conserving Water Through Pricing," J. of the American Water Works Association, January 1982.

Russell, J.D., "Seasonal and Time-of-Day Pricing," J. of the American Water Work. Association, September 1984.

Simmons, C., Director of Public Utilities, City of Raleigh. Facsimile transmittal dated July 7, 1992.

Southwest Florida Water Management District (SWWMD), Water Conservati-on Opportunities for Local Governments. Technical Information Planning Series - 88-1, August 1988.

Thangle J Council of Governments. Water and Wastewater System Profiles (prepared at &ginning of study), April 1992.

U.S. Army Corps of Engineers Institute for Water Resources, The Role of Conservation in Water SuppIv Planning. Contract Report 79-2, April 1979.

U.S. Environmental Protection Agency, Water Reclamation Reuse Guidelines -- Preliminary Draft, October 199 1.

Watts, KN., Water Reuse in Selected States. Water Resources Research Institute of the University of North Carolina. January 1992.

APPENDIX A

SUMMARY TABLES OF WATER CONSERVATION SCENARIOS

TABLE A-1

Row

1 2

MODERATE CONSERVATION SCENARlO FOR THE TOWN OF CARY -

Potential Range of

Measures & Water Use of Savings Estimated 96 Category Impacted (Yr 2010) Coverage Savings

Public Education 0% - 4% 50% 0 % - 2% New Building Codes (ResidIComm) 6% - 8% 100% 6 % - 8%

3 4

Retrofit Existing Development Residential CommerciaVlnsti tutional

I I t 5 iC/I/l Recycling (Water Audits) I I I 6 IVariable Rate Structures I 1

ITOTAL 6% - 10961 Notes * * * * * * * *

* * * * * * * * *

Estimated Savings = Potential Range of Savings Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 - (%Res . + 96Com. + %Inst.) * (2010 Demand - 1990 Demand)

Row 3 - (1990 Residential Demand / 2010 Demand) * (Range from 15% to 25%) Row 4 - (1990 Comm. Demand + 1990 Inst. Demand) / 2010 Demand

Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 10.8 mgd 1990 Residential Demand 4.26 mgd or 69.0 96 1990 Commercial Demand 0.92 mgd or 14.9 % 1990 Industrial Demand 0.23 mgd or 3.7 96 1990 Institutional Demand 0.35 mgd or 5.6 96 1990 Unaccounted-for 0.42 mgd or 6.8 96 1990 Total Demand 6.18 mgd or 100 96

/ 2010 Demand * (Range from 15% to 20%)

* (Range from 5% to 20%)

TABLE A-2

Row

AGGRESSIVE CONSERVATION SCENARIO FOR THE TOWN OF CARY -

Potential Range of

of Savings Category Impacted (Yr 2010)

Measures & Water Use 1 Coverage I

75% 100%

Estimated 96 Savings

0 % - 396 6 % - 8% ~

3 1 Residential 4 Commercial/Institutional

1 2

Public Education 0% - 4% New Building Codes (ResidIComm) 696 - 8% Retrofit Existing Development

Notes * * * *

* * *

* * * * * * * * *

5 6

~ ~~

C/UI Recycling (Water Audits) Variable Rate Structures 0% - 10% 10096 096- 1096 6

ITOTAL 896 - 26961

Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + 96Com. + 96Inst.) * (2010 Demand - 1990 Demand)

Row 3 - (1990 Residential Demand / 20 10 Demand) * (Range from I5 % to 25 96) Row 4 - (1990 Comm. Demand + 1990 Inst. Demand) / 2010 Demand

Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 10.8 mgd 1990 Residential Demand 4.26 mgd or 69.0 96 1990 Commercial Demand 0.92 mgd or 14.9 96 1990 Industrial Demand 0.23 mgd or 3.7 96 1990 Institutional Demand 0.35 mgd or 5.6 96 1990 Unaccounted-for 0.42 mgd or 6.8 % 1990 Total Demand 6.18 mgdor 100 96

/ 2010 Demand * (Range from 1596 to 20%)

* (Range from 596 to 20%)

TABLE A-3

Row

1 2

3

MAXIMUM CONSERVATION SCENARIO FOR THE TOWN OF CARY -

Potential Range of

Measures & Water Use of Savings Estimated 5% Category Impacted (Yr 2010) Coverage Savings

Public Education 0% - 4% 100% 0%- 4% New Building Codes (ResidjComm) 6% - 8% 100% 6 % - 8% Retrofit Existing Development

Residential 6% - 10% 60%- 70% 4%- 7%

5 6

C/l/I Recycling (Water Audits) Variable Rate Structures 0% - 10% 100% 0%- 10%

Notes * * * * * * * *

* *

* * * * * *

Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + ZCom. + %Inst.) * (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 10.8 mgd 1990 Residential Demand 4.26 mgd or 69.0 95 1990 Commercial Demand 0.92 mgd or 14.9 96 1990 Industrial Demand 0.23 mgd or 3.7 96 1990 Institutional Demand 0.35 mgd or 5.6 96 1990 Unaccounted-for 0.42 mgd or 6.8 96 1990 Total Demand 6.18 mgd or 100 96



TABLE A 4

Row

1 2

3 4 5 6

MODERATE CONSERVATION SCENARIO FOR THE ORANGE WATER AND SEWER AUTHORITY -

Potential Range of


Public Education 0% - 4% 50% 0%- 2% New Building Codes (ResidiComm) 5% - 6% 100% 5%- 6% Retrofit Existing Development

Residential 4% - 7% 15%- 20% 1 % - 1% Commercial/Institutional 2% - 7% 15%- 20% 0%- 1%

C/YI Recycling (Water Audits) Variable Rate Structures

* * * * * * * *

* * * * * * * * *

Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + 96Com. + %Inst.) * (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 1 1 mgd 1990 Residential Demand 3.16 mgd or 42.8 96 1990 Commercial Demand 0.45 mgd or 6.1 % 1990 Industrial Demand 0.00 mgd or 0.0 96 1990 Institutional Demand 3.16 mgd or 42.8 % 1990 Unaccounted-for 0.61 mgd or 8.3 % 1990 Total Demand 7.38 mgd or 100 96



TABLE A-5

AGGRESSIVE CONSERVATION SCENARIO FOR THE

Row

1 2

ORANGE WATER AND SEWER

Potential Range of

of Savings (Yr 2010)

Public Education 0% - 4% New Building Codes (ResidIComm) 5% - 6%

3 4


4% - 7% 2% - 7%

5 6

C/I/I Recycling (Water Audits) Variable Rate Structures 0% - 10%

Notes * * * * * * * *

* * * * *

* * *

AUTHORITY

Coverage

75 st 100%

30% - 50% 30% - 50%

100%

-

Estimated % Savings

0 % - 3% 5 % - 6%

1 % - 4% 0 % - 3%

0 % - 10%

TOTAL 6% - 26%

Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. .Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + %Com. + %Inst.) * (2010 Demand - 1990 Demand)

Row 3 - (1990 Residential Demand / 2010 Demand) * (Range from 15% to 25%) Row 4 - (1990 Comm. Demand + 1990 Inst. Demand) / 20 10 Demand

Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 11 mgd 1990 Residential Demand 3.16 mgd or 42.8 % 1990 Commercial Demand 0.45 mgd or 6.1 % 1990 industrial Demand 0.00 mgd or 0.0 96 1990 Institutional Demand 3.16 mgd or 42.8 % 1990 Unaccounted-for 0.61 mgd or 8.3 % 1990 Total Demand 7.38 mgd or 100 96



TABLE A-6

Measures & Water Use Row

1 Public Education 2 New Building Codes (ResidKomm)

3 Residential 4 Commercial/Institutional

6 Variable Rate Structures


5 C/I/I Recycling (Water Audits)

MAXIMUM CONSERVATION SCENARIO FOR THE ORANGE WATER AND SEWER AUTHORITY

Potential Range of

of Savings Estimated 96 (Yr 2010) Coverage Savings

0% - 4% 100% 0 % - 4% 5% - 6% 100% 5 % - 6%

4% - 7% 60%- 70% 3 % - 5 % 2% - 7% 60%- 70% 1 % - 5 % 0% - 3% 40% 0 % - 1% 0% - 10% 100% 0 % - 10%

* * * * *

* *

* * *

*

* * *

Notes Estimated Savings = Potential Range of Savings Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + 9bCom. + %Inst.) (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 11 mgd 1990 Residential Demand 3.16 mgd or 42.8 96 1990 Commercial Demand 0.45 mgd or 6.1 96 1990 Industrial Demand 0.00 mgd or 0.0 96 1990 Institutional Demand 3.16 mgd or 42.8 96 1990 Unaccounted-for 0.61 mgd or 8.3 96 1990 Total Demand 7.38 mgd or 100 96



TABLE A-7

I

MODERATE CONSERVATION SCENARIO FOR THE CITY OF RALEIGH -

Row 1 2

3 4

Potential Range of

of Savings Category Impacted (Yr 2010)

Measures & Water Use

Public Education 0% - 4% New Building Codes (ResidIComm) 7% - 9% Retrofit Existing Development

Residential 2% - 4% Commercial/Institutional 1% - 5 %

Coverage 50%

100%

15%- 20% 15%- 20%

Notes


0 % - 2% 7%- 9%

0 % - 1% 0 % - 1%

* * * * * * * *

* * * * * * * * *

5 6

C/UI Recycling (Water Audits) Variable Rate Structures

ITOTAL I 7% - 13961



Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 70 mgd 1990 Residential Demand 10.71 mgd or 32.1 96 1990 Commercial Demand 11.09 mgd or 33.2 % 1990 Industrial Demand 2.89 mgd or 8.7 96 1990 Institutional Demand 6.09 mgd or 18.2 96 1990 Unaccounted-for 2.60 mgd or 7.8 % 1990 Total Demand 33.38 mgdor 100 96



TABLE A-8

AGGRESSIVE CONSERVATION SCENARIO FOR THE CITY OF RALEIGH

-

_ .

Row 1

Measures & Water Use Category Impacted

Public Education #New Buildine Codes (Resid/Comm) Retrofit Existing Development

Residential

Potential Range of

of Savings (Yr 2010) 0% - 4% 7% - 9%

2% - 4% 1% - 5%

0% - 10%

Coverage 75 %

100%

30% - 50% 30% - 50%

100%

Estimated % Savings

0 % - 3% 7 % - 9%

* * * * * * * *

* * * * * * * * *

Notes Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + %Com. + %Inst.) * (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 70 mgd 1990 Residential Demand 10.71 mgd or 32.1 % 1990 Commercial Demand 11.09 mgd or 33.2 % 1990 Industrial Demand 2.89 mgd or 8.7 % 1990 Institutional Demand 6.09 mgd or 18.2 % 1990 Unaccoun ted-for 2.60 mgd or 7.8 % 1990 Total Demand 33.38 mgd or 100 %



TABLE A-9

Measures & Water Use Category Impacted

Public Education New Building Codes (ResidlComm) Retrofit Existing Development

Residential Commercialhsti tutional

ClUI Recycling (Water Audits) Variable Rate Structures

MAXIMUM CONSERVATION SCENARIO FOR THE CITY OF RALEIGH -

Potential Range of

of Savings (Yr 2010) 0% - 4% 7% - 9%

2% - 4% 1% - 5% 0% - 3% 0% - 10%

Row 1 2

3 4 5 6

- Coverage 100% 100%

60%- 70% 60%- 70%

40% 100%


0 % - 4% 7 % - 9%

2 % - 3% 1 % - 3% 0 % - 1% 0 % - 10%

ITOTAL I 10% - 30961 Notes * * * * * * * *

* * * * * * * * *



Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 70 mgd 1990 Residential Demand 10.71 mgd or 32.1 96 1990 Commercial Demand 11.09 mgd or 33.2 % 1990 Industrial Demand 2.89 mgd or 8.7 96 1990 Institutional Demand 6.09 mgd or 18.2 96 1990 Unaccounted-for 2.60 mgd or 7.8 96 1990 Total Demand 33.38 mgdor 100 96



TABLE A-10

Row

1

MODERATE CONSERVATION SCENARIO FOR THE TOWN OF SANFORD -

Potential Range of


3

Public Education 0% - 4% 50% 0 % - 2% 2

3 4 5 6

New Building Codes (ResidIComm) 5% - 7% 100% 5 % - 7% Retrofit Existing Development

Residential Commercial/Institutional

C/VI Recycling (Water Audits) Variable Rate Structures

* * *

* * * *

* * * * * * * * *

Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + %Com. + %Inst.) * (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 8.35 mgd 1990 Residential Demand 2.88 mgd or 68.0 % 1990 Commercial Demand 0.00 mgd or 0.0 96 1990 Industrial Demand 1.35 mgd or 32.0 96 1990 Institutional Demand 0.00 mgd or 0.0 96 1990 Unaccounted-for 0.00 mgd or 0.0 96 1990 Total Demand 4.234 mgdor 100 5%



TABLE A-1 1

Row

1

AGGRESSIVE CONSERVATION SCENARIO FOR THE TOWN OF SANFORD -

Potential Range of

of Savings Estimated 96 Category Impacted (Yr 2010) Coverage Savings

Public Education 0% - 4% 75% 0 % - 3% 2

3 4 5 6

New Building Codes (Resid/Comm) 5% - 7% 10096 5 % - 7% Retrofit Existing Development

Residential 5% - 9% 30%- 50% 2 % - 4% Commercial/Insti tutional

C/I/l Recycling (Water Audits) Variable Rate Structures 0% - 10% 10096 0 % - 10%

* * * * * * * *

4

* * * * * * * *

TOTAL 7% - 24% Notes



Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 8.35 mgd 1990 Residential Demand 2.88 mgd or 68.0 % 1990 Commercial Demand 0.00 mgd or 0.0 96 1990 Industrial Demand 1.35 mgd or 32.0 96 1990 Institutional Demand 0.00 mgd or 0.0 96 1990 Unaccounted-for 0.00 mgd or 0.0 % 1990 Total Demand 4.234 mgdor 100 96



TABLE A-12

Row

1 2

3 4 5 6

MAXIMUM CONSERVATION SCENARIO FOR THE TOWN OF SANFORD -

Potential Range of

Measures & Water Use of Savings Estimated % Category Impacted (Yr 2010) Coverage Savings

Public Education 0% - 4% 100% 0 % - 4% New Building Codes (ResidIComm) 5% - 7% 100% 5 % - 7% Retrofit Existing Development

Residential 5% - 9% 60%- 70% 4 % - 6% Commercial/Insti tutional

C/I/I Recycling (Water Audits) 0% - 2% 40% 0 % - 1% Variable Rate Structures 0% - 10% 100% 0 % - 10%

Notes * * * * * * * *

* * * * * * *

*



Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 8.35 mgd 1990 Residential Demand 2.88 mgd or 68.0 % 1990 Commercial Demand 0.00 mgd or 0.0 % 1990 Industrial Demand 1.35 mgd or 32.0 96 1990 Institutional Demand 0.00 mgd or 0.0 96 1990 Unaccounted-for 0.00 mgd or 0.0 % 1990 Total Demand 4.234 mgd or 100 %


* (Range from 5 % to 20%)

TABLE A-13

Row

1 2

3 4 5

MODERATE CONSERVATION SCENARIO FOR THE TOWN OF SMITHFIELD -

Range of of Savings

Category Impacted (Yr 2010) Measures & Water Use

Public Education 0% - 4% New Building Codes (ResidIComm) 2% - 2% Retrofit Existing Development

Residential 6% - 10% Commercial/Institutional

C/YI Recycling (Water Audits)

1 I Potential

15%- 20% 1 % -

6 /Variable Rate Structures I

Estimated 96

TOTAL 3 % - 6 4 Notes * * * *

* * *

* * * * * * * * *



Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 3.6 mgd 1990 Residential Demand 1.49 mgd or 49.0 k 1990 Commercial Demand 0.46 mgd or 15.0 96 1990 Industrial Demand 0.58 mgd or 19.0 % 1990 Institutional Demand 0.33 mgd or 11.0 96 1990 Unaccounted-for 0.18 mgd or 6.0 96 1990 Total Demand 3.045 mgd or 49.0 96



TABLE A-14

Category Impacted (Yr 2010) Coverage i

-

Row

1 2

- - - IPublic Education I 0% - 4961 75 9E

3 4 5 -

New Building Codes (ResidXomm) 2% - 2% 100% Retrofit Existing Development

I Residential 6% - 10% 30%- 50% CommerciaVIns ti tu tional

6 - C/I/I Recycling (Water Audits) Variable Rate Structures

Notes * * * * * * * *

* * * * * * * * *

0% - 4% 40% 0% - 10% 100%

AGGRESSIVE CONSERVATION SCENARIO FOR THE TOWN OF SMITHFIELD -

Potential Range of

of Savings 1 Estimated 96

0%- 3%

2 % - 5% 0 % - 0% 0% - -2961 0 % - 10% __i ITOTAL 4% - 22961


Row 3 - ( 1990 Residential Demand / 2010 Demand) * (Range from 15 4% to 25 %) Row 4 - (1990 Comm. Demand + 1990 Inst. Demand) / 2010 Demand

Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 3.6 mgd 1990 Residential Demand 1.49 mgd or 49.0 1990 Commercial Demand 0.46 mgd or 15.0 1990 Industrial Demand 0.58 mgd or 19.0 1990 Institutional Demand 0.33 mgd or 11.0 1990 Unaccounted-for 0.18 mgd or 6.0 1990 Total Demand 3.045 mgd or 49.0


* (Range from 5 % to 20 96)

TABLE A-15

Row

1 2

3 4 5 6

MAXIMUM CONSERVATION SCENARIO FOR THE TOWN OF SMITHFIELD -

Potential Range of

Measures & Water Use of Savings Estimated % Category Impacted (Yr 2010) Coverage Savings

Public Education 0% - 4% 100% 0%- 4% New Building Codes (ResidKomm) 2% - 2% lM% 2%- 2% Retrofit Existing Development

Residential 6% - 10% 60%- 70% 4%- 7% Commercial/Institutional

C/VI Recycling (Water Audits) 0% - 4% 40% 0%- 2% Variable Rate Structures 0% - 10% 100% 0%- 10%

* * * * * * * *

* * * * * e

* * *

Notes Estimated Savings = Potential Range of Savings * Coverage Coverage refers to percent of water use expected to be impacted by program. Potential Range of Savings are estimated as follows: Row 1 - assumed based on knowledge of other public education programs Row 2 -(%Res. + 96Com. + %Inst.) * (2010 Demand - 1990 Demand)


Row 5 - assumed based on knowledge of other water audit programs. Row 6 - assumed based on reports of results in other communities. Projected 2010 Demand 3.6 mgd 1990 Residential Demand 1.49 mgd or 49.0 1990 Commercial Demand 0.46 mgd or 15.0 1990 Industrial Demand 0.58 mgd or 19.0 1990 Institutional Demand 0.33 mgd or 11.0 1990 Unaccounted-for 0.18 mgd or 6.0 1990 Total Demand 3.045 mgd or 49.0



APPENDIX B

SUPPLEMENTAL CALCULATION TABLES FOR EVALUATION OF WATER CONSERVATION SCENARIOS

CARY _ .

I without

Table B-1

WATER TREATMENT PLANT EXPANSION (all flows in mgd) -

ESTIMATED SAVINGS FROM DEFERRED CAPITAL COSTS

With Conservation (96 reduction) Moderate I Aggressive I Maximum

(5 96) Avg I Max

konserva ti on (15%) Avg I Max

Demands in mgd in Year 1990 Demands in mgd in Year 1993 Demands in mnd in Year 2010

Maximum Day Design Factor Existing Treatment Capacity Year Plant Expansion Needed

Avg Max Day Day 6.2 9.6 6.9 10.7 10.8 16.7

1.55 12

1996.7

Day 6.2

Day Day Day 9.6 6.2 9.6

of Expansion, million $ Savings, million $

6.9 I 10.7 I 6.9 I 10.7

1.90 1.82 1.57 1 .os 0 0.08 1 0.33 1 0.86

12 1997.3 l2 I 1999.4

4

Avg Day 6.2 6.9 8.1

Equivalent Annual Savings,

2005.0

million $ 0 1 0.008 1 0.034 0.09 Notes * Discount rate = 7.5% * *

Year expansion needed estimated using linear interpolation/extraplation of demands. Water treatment plant expansion cost assumed to be $0.5/gal of expanded capacity.

Without Conservation

6.18 6.873

10.8

(million $) 0

Avg Day Flow in 1990, mgd Avg Day Flow in 1993, mgd Avg Day Flow in 2010, mgd Savings in Yr 2010

Increase in SavingsIYr

Present Value of Savings

Equivalent Annual Value

(million $) 0

(million $) 0

(million $) 0

With Conservation (% reduction) Moderate Aggressive Maximum

(5%) (15%) (25 % 1 6.18 6.18 6.18

6.873 6.873 6.873 10.26 9.18 8.1

0.039 0.118 0.197

0.002 0.007 0.01 1

0.151 0.42 1 0.702

0.0 16 0.043 0.072 Marginal Operating Cost = 0.2 f/1000 gal

Table B-3 ESTIMATED SAVINGS FROM DEFERRED CAPITAL COSTS

WASTEWATER TREATMENT PLANT EXPANSION - (all flows in mgd) -

CARY

Notes * Discount rate = 7.5% * *

*

Year expansion needed estimated using linear interpolation/extrapolation of demands. Assumed existing wastewater flows to be 84% of existing water use (84% equals the ratio of 2010 wastewater to water flows provided by TJCOG) Wastewater treatment plant expansion cost assumed to be 61.6Vgal expanded capacity.

Table B-4 ESTIMATED ANNUAL COSTS OF WATER CONSERVATION PROGRAM

CARY

Conservation Measure Public Education

$/household Total Estimated Annual Cost

Building/Development Codes Labor (person-months) Labor Cost @$35,000/yr

Cost per household Residential Cost Commercial Retrofit Cost Total Estimated Annual Cost

-


Leak Detection and Repair C/I/I Recycling (Water Audits)

Expected Number of Audits Annual cost @ $3000/audit

Variable Rate Structures Water Use Ordinance

Enforcement Costs Total Estimated Annual Cost

TOTALS


1 2 4 18,000 %oO0 no00

0 0 3 0 0 8,750

0 50 450 0 50,000 450,000 0 0 33,400 0 m)0O 483,400 0 0 0

0 0 10 0 0 3o.OOo 0 0 0

0 0 8,750 0 0 8,750

$18.000 $86,000 $603,000 >

Notes * *

* *

*

Retrofit costs are distributed evenly over 18 year planning period Moderate retrofit assumes bulk mailing or central depot distribution of conservation kits Aggressive retrofit assumes door-to-door distribution of conservation kits Maximum retrofit assumes direct installation of low-flush toilets and low-flow fixtures (two bathrooms per household) Commercial retrofit costs = residential retrofit cost *

Average Daily Use ( 199 1) 6.18 mgd Projected Use (2010) 10.8 mgd % Residential 74.0% % Commercial 16.0% % Institutional 6.0% Number of existing (1990) households

(% commercial + %institutional) / 96 residential * 25%

18,000

Table B-5 ESTIMATED LOSS IN REVENUES FROM -

IMPLEMENTING WATER CONSERVATION -

(millions of $)


6.31 7.0 1

11.02

1990 Water & Sewer Revenues Est 1993 Water & Sewer Revenuer Est 2010 Water & Sewer Revenue; Revenue Loss in Yr 2010

Marginal Loss/Yr

Present Value of Loss


(million $) 0

(million $) 0

(million $) 0

(million $) 0

With Co Moderate

(5%) 6.31 7.01

10.47

0.55 1

0.03 1

1.963

0.202

iservation (% Aggressive

(15%) 6.3 1 7.0 1 9.37

1.653

0.092

5.890

0.607

reduction) Maximum

(25 96 ) 6.31 7.01 8.27

2.755

0.153

9.816

1.01 1

Notes * Discount rate = 7.5% * 1990 water & sewer revenues obtained from NCLM survey, 1990. * 2010 water & sewer revenues estimated assuming 1990 water rates and 2010 demands.


WATER TREATMENT PLANT EXPANSION- (all flows in mgd) -

OWASA - I With Conservation (96 reduction)


Year expansion needed estimated using linear interpolation/extraplation of de Cost of expansion provided by OWASA staff

:I

Maximum (25 %

12.4

1.54 12.5

1998.6

1.33 0.62

0.07

mands.

Table B-7

-


7.53 8.05

11

(million $1 0


ESTIMATED SAVINGS FROM REDUCED OPERATION & MAINTENANCE COSTS -

AT WATER TREATMENT PLANT -

With Co Moderate

(596) 7.53 8.05

10.45

0.060

(1596) 7.53 8.05 9.35

0.181

(25%) ,

7.53 8.05 8.25

0.301

I (million $) 01 0.23 1 I


Present Value of Savings (million $) 0 0.003

Equivalent Annual Value I (million $1

0.0 10 I 0.017

0 I 0.024

1.073

0.066 0.114 [Marginal Operating Cost = 1 0.3 $/1000gal Notes * Discount rate = 7.5% * Marginal Operating Cost computed from budget data provided by OWASA staff.


WASTEWATER TREATMENT PLANT EXPANSION (all flows in mgd)

- OWASA

With Conservation (96 reduction)

Flows in mgd in Year 1990 Flows in mgd in Year 1993 Flows in mgd in Year 2010

Maximum Month Design Factor Existing Treatment Capacity Year Plant Expansion Needed Projected Demand for 15 Yr Plan Period, mnd WWTP Expansion Capacity, mgd Cost of Expansion, million S Discount Rate Present Value Cost Expansion, million $ Savings, million $ Equivalent Annual Savings million $ Notes


1.2 12

2020.9

15 3

4.95 7.5 9E

0.657 0

Moderate Aggressive

Avg Max Avg Max Day Mon Day Mon 5 .o 6.0 5.0 6.0 5.4 6.5 5.4 6.5 7.8 9.4 7.0 8.4

(596) (1596)

* Discount rate = 7.5% *

* *

Wastewater treatment plant capacity of 12 mgd will be online August 1993. This expansion could not be delayed by conservation. Flows in Years 1990, 1993, and 2010 provided by OWASA staff. Maximum Month Design Factor of 1.2 provided by OWASA staff.

Maximum (25 96 )

~

7.4 I .2 12

2097.2

0.00 0.6541

0.07

* *

Year expansion needed estimated using linear interpolation/extrapolation of demands. Wastewater treatment plant expansion cost assumed to be $1.65/gal expanded capacity.


OWASA



Building/Development Codes Labor @erson-months) Labor Cost @$35,000/yr

Retrofit Existing Development Cost per household Residential Cost Commercial Retrofit Cost Total Estimated Annual Cost

Leak Detection and Repair C/VI Recycling (Water Audits)

Expected Number of Audits Annual cost 43 $3000/audit

Variable Rate Structures ~~~~~~ ~~

Water Use Ordinance Enforcement Costs Total Estimated Annual Cost

TOTAIS

c o Moderate

1 21 ,Ooo

0 0

15 17,500 5 ,000 22,500

0

0 0 0

0 0

w.oO0

servation S& Aggressive

2 42.000

0 0

~~

50 58,300 16,600 74,900

0

0 0 0

4.375 4,375

$121,000

Mi0

Maximum

4 84.000

3 8,750

450 525,000 149,600 674,600

0

10 3o.oO0

0

8,750 8,750

$806,000

Notes * Retrofit costs are distributed evenly over 18 year planning period * Moderate retrofit assumes bulk mailing or central depot distribution of

conservation kits * Aggressive retrofit assumes door-to-door distribution of conservation kits

Maximum retrofit assumes direct installation of low-flush toilets and low-flow fixtures (two bathrooms per household)

* Commercial retrofit costs = residential retrofit cost *

* Average Daily Use (1991) 7.53 mgd * Projected Use (2010) 1 1 mgd * 96 Residential 43.0% * 96 Commercial 6.0% * 96 Institutional 43.0%

(96 commercial + %institutional) / 96 residential * 25%

* Number of existing (1990) households 21,000


8.785 9.392 12.83

(million $) 0

(million $) 0

(million $) 0

1990 Water & Sewer Revenues Est 1993 Water & Sewer Revenuer Est 2010 Water & Sewer Revenue5 Revenue Loss in Yr 2010

Marginal Loss/Y r


Equivalent Annual Value (million $) 0

Notes * Discount rate = 7.5% * 1990 water & wewer revenues obtained from NCLM survey, 1990. * 2010 water & sewer revenues estimated assuming 1990 water rates and 2010 demands.

With Conservation (96 reduction) Moderate Aggressive Maximum

8.785 8.785 8.785 9.392 9.392 9.392 12.19 10.908 9.6247

0.642 1.925 3.208

0.036 0.107 0.178

2.286 6.857 11.429

0.235 0.706 1.177

(596) (1596) (25 96 )

Table B-1 1

WATER TREATMENT PLANT EXPANSION (all flows in mgd)


RALEIGH -

- Aggressive

Avg Max Day Day 33.4 49.3 38.9 57.5 59.5 88.1

(15%)

Demands in mgd for Year 1990 Demands in mgd for Year 1993 Demands in mgd for Year 2010

Maximum Day Design Factor Existing Treatment Capacity, mgc Year Plant Expansion Needed Projected Demand for

Maximum

Avg Max Day Day 33.4 49.3 38.9 57.5 52.5 77.7

(25 % 1 Without

Conservation

57.5

15 Yr Plan Period, mgd WTP Expansion Capacity, mnd

1.48 62.5

1994.8

103 37.5

Cost of Expansion, million $ Discount Rate Present Value Cost of Expansion, million $ Savinns, million $

14.14 7.5 9

12.38 O.OO0

Equivalent Annual Savings, million $

With Cc

0.o00

Moderate

98.4

iservation (96 reduction)

1.48 62.5

1995.0

1.48 62.5

1995.7

1.48 62.5

1997.1

12.18 I 11.58 I 10.45 0.206 I 0.808 I 1.94

0.020 I 0.080 1 0.20 ~~ ~ ~~


Size and cost of treatment plant expansion provided by City of Raleigh staff Year expansion needed estimated using linear interpolation/extrapolation of demands.

- Without Conservation

33.38 38.87

70

(million $) 0

(million $) 0

(million $) 0

(million $) 0


Increase in SavingdYr



With Conservation (96 reduction)

(596) (15%) (25 96 ) Moderate Aggressive Maximum

33.38 33.38 33.38 38.87 38.873 38.873 66.5 59.5 52.5

0.230 0.690 1,150

0.013 0.038 0.064

0.88 1 2.457 4.096

0.091 0.253 0.422 Marginal Operating Cost = 0.18 $/lo00 gal


WASTEWATER TREATMENT PLANT EXPANSION (all flows in mgd) -

RALEIGH - With Conservation (96 reduction)

Flows in mgd for Year 1990 Flows in mgd for Year 1993 Flows in mgd for Year 2010

Without 1 Mod;;; I Ag;;;ff’ Conservation

Day 29.8 33.6 55.2

Expansion, million $ Savings, million $ Equivalent Annual Savings million $

Max Mon

3.408 2.314 0.659 O.OO0 I .094 2.750

0.110 0.280

44.7 50.4 82.8

1.5 120

-51 52.4 78.7

50.4

1.5 120

15 Yr Plan Period. mnd - WWTP Expansion Capacity, mgd I 29 I Cost of Expansion, million $ I 47.85 I

Maximum (25 % 1

41.4 1 .5 120

2094.2

~~~

0.03 3.3765

0.35

* *



Moderate Aggressive

RALEIGH

Maximum Conservation Measure Public Education


Building/Development Codes Labor (person-months) Labor Cost @$35,000/yr

Retrofit Existing Development Cost per household Residential Cost Commercial Retrofit Cost Total Estimated Annual Cost

-


93,000

0 0

15 77,200 30,900

108,100 0

C/I/I Recycling (Water Audits) Expected Number of Audits Annual cost @ $3000/audit



185,000 371 ,OOO

0 3 0 8,750

50 450 257,400 2,316,300 103,000 927,200 360,400 3,243,500

0 0 I

TOTALS

0 0

10 3o.OOO

2 1 4

0 0

8,750 17,500 8,750 I 17,500

$20 1 ,OOO $554,000 $3,67 1 ,OOO Notes * Retrofit costs are distributed evenly over 18 year planning period

Moderate retrofit assumes bulk mailing or central depot distribution of conservation kits

* Aggressive retrofit assumes door-todoor distribution of conservation kits * Maximum retrofit assumes direct installation of low-flush toilets and

low-flow fixtures (two bathrooms per household) * Commercial retrofit costs = residential retrofit cost *

* Average Daily Use (1991) 33.38 mgd * Projected Use (2010) 70 mgd * 96 Residential 32.196 * 96 Commercial 33.2% * 96 Institutional 18.2% * Number of existing (1990) households 92,650

(96 commercial + %institutional) / 96 residential * 25%

Table B-15 ESTIMATED LOSS IN REVENUES FROM

IMPLEMENTING WATER CONSERVATION (millions of $)

-


23.60 27.48 49.49

(million $) 0

1990 Water & Sewer Revenues Est 1993 Water & Sewer Revenues Est 2010 Water & Sewer Revenuer Revenue Loss in Yr 2010

with co Moderate

(5%) 23.60 27.48 47.0 1

2.47

Aggressive (15%) 23.601 27.485 42.069

7.42

0.412

Maximum

23.60 27.49 37.12

12.37

0.687

(25 96 )

Marginal Loss/Yr



(million $)

(million $)

(million $1


0 0.137

0 8.82

0 0.908

26.45

2.725 I

44.08

4.541 ,

Without

Demands in mgd in Year 1990 Demands in mgd in Year 1993 Demands in mgd in Year 2010

Maximum Day Design Factor Existing Treatment Capacity Year Plant ExDansion Needed

With Conservation (96 reduction) Moderate 1 Aggressive I Maximum

Max Day

6.4 7.4

12.1 1.52

12 2009.7

Avg Day

4.2 4.8 8.4

Avg Day 4.2 4.8 7.1

Max Day

6.4 7.4

12.7 1.52

12 2007.7

Present Value Cost of Expansion, million $ Savings, million $ Equivalent Annual Savings, million $

Avg Day

4.2 4.8 7.9

0.86 0.74 0.47 0.18 0 0.12 0.38 0.68

0 0.0 12 0.040 0.07

1.52 12

20 16.0

1.52 12

2029.6

Table B-17 ESTIMATED SAVINGS FROM REDUCED OPERATION & MAINTENANCE COSTS

AT WATER TREATMENT PLANT - SANFORD


4.23 4.848 8.35

(million $) 0

(million $) 0

(million $) 0

(million $) 0






(5%) (15%) (=%) 4.23 4.23 4.23 4.848 4.848 4.848 7.932 7.0975 6.2625

0.030 0.09 1 0.152

0.002 0.005 0.008

0.117 0.326 0.543

0.0 12 0.034 0.056 Marginal Operating Cost = 0.2 $/1000gal


WASTEWATER TREATMENT PLANT EXPANSION (all flows in mgd)

SANFORD - r 1

Without

Flows in mgd in Year 1993 Flows in mgd in Year 2010


Avg Day

3.3 3.6 5.0

Conservation (596) (1596) (25%) ,

Max Avg Max Avg Max Mon Day Mon Day Mon 5.0 3.3 5.0 3.3 5.0 5.4 3.6 5.4 3.6 5.4 7.1 4.3 6.4 3.8 5.6

5.0 3.3 5.4 3.6 + 7.5 4.8

I 0.026 I 0.099 0.17

6.8 1.5 I Maximum Month Design Factor Existing Treatment Capacity

2006.7 Projected Demand for

Expansion, million $

Equivalent Annual Savings million $ Notes * Discount rate = 7.5% * *



Public Education $/household Total Estimated Annual Cost

Labor (person-months) Labor Cost @$35,000/yr




Leak Detection and Repair C / M Recycling (Water Audits)




SANFORD ervation Scenario 1

1 6,000

0 0

0 0 0 0 0

0 0 0

0 0

Conservation Measure

0 0

50 17,300

0 17,300

0

td

3 8,750

450 155,600

0 155,600

0

0 0

4,375 4,375

TOTALS $6,000

Notes

30,000. 0

8,750 8,750

Aggressive Maximum T 12.000 * I 25.OOo 4 1

I

- - _ _

* Retrofit costs are distributed evenly over 18 year planning period * Moderate retrofit assumes bulk mailing or central depot distribution of

conservation kits * Aggressive retrofit assumes door-to-door distribution of conservation kits * . Maximum retrofit assumes direct installation of low-flush toilets and

low-flow fixtures (two bathrooms per household) * Commercial retrofit costs = residential retrofit cost *

* Average Daily Use (1991) 4.234 mgd * Projected Use (2010) 8.35 mgd * 96 Residential 68.0% * 96 Commercial 0.0% * % Institutional 0.0% * Number of existing (1990) households 6,223

(% commercial + %institutional) / 96 residential * 25%

..


IMPLEMENTING WATER CONSERVATION (millions of $) -

With Conservation (96 reduction) Without Moderate Aggressive Maximum

1990 Water & Sewer Revenues 4.1 4.1 4.1 4.1 Est 1993 Water & Sewer Revenuer 4.699 4.699 4.699 4.699 Est 2010 Water & Sewer Revenues 8.093 7.688 6.8790 6.0697 Revenue Loss in Yr 2010

Marginal Loss/Yr



Con Serva ti on (596) (15%) (25 96 1

(million $) 0 0.405 1.214 2.02

(million $) 0 0.022 0.067 0.112

(million $) 0 1.441 4.324 7.207

(million $) 0 0.149 0.446 0.743 -


Table B-21

WATER TREATMENT PLANT EXPANSION- (all flows in mgd) -


SMITHFIELD

lwTP Expansion Capacity, mgd Cost of Expansion, million $ Discount Rate

I With Conservation (96 reduction)

0.224

Demands in mgd in Year 1990 Demands in mgd in Year 1993 Demands in mrrd in Year 2010

0.00

Maximum Day Design Factor Existing Treatment Capacity Year Plant Expansion Needed Projected Demand for 15 Yr Plan Period. mgd

Present Value Cost of Expansion. million $ Savings. million $ Equivalent Annual Savings, million $

without Conservation

4.4 6.9 1.56

6

Moderate

3.3 5.1 4.2 6.5

1.56 6

0.529 I 0.455 0.074 I

(1596) (25 96 )

3.3 3.7

5

0.306

0.03 1 Notes * Discount rate = 7.5% *

* *

Assumed projected 2010 water use of 4.4 mgd (projected wastewater flow is 4.2 mgd for 2010) Year expansion needed estimated using linear interpolation/extrapolation of demands. Water treatment plant expansion cost assumed to be $Q.S/gal of expanded capacity.


3.05 3.25 4.4

(million $) 0

Avg Day Flow in 1990, mgd Avg Day Flow in 1993, mgd

Savings in Yr 2010

Increase in Savingsly r



Avg Day Flow in 2010, mgd

(million $) 0

(million $) 0

(million $) 0


(596) (1596) (25 96 1 3.05 3.05 3.05 3.25 3.25 3.25 4.18 3.74 3.3

0.0 16 0.048 0.080

0.00 1 0.003 0.004

0.062 0.172 0.286

0.006 0.018 0.029 Marginal Operating Cost = 0.2 $/loo0 gal

Expansion, million $ Savings, million $ Equivalent Annual Savings million $

0.72 1 0.592 0.228 O.OO0 0.72 1 0.0oO 0.128 0.493

0.013 0.05 1 0.080



$/household

SMITHFIELD I I Conservation Scenario

L

Moderate Aggressive Maximum

1 2 4 Total Estimated Annual Cost


Labor Cost @$35,000/yr


Labor (person-months)


Leak Detection and Repair C/I/I Recycling (Water Audits)




3,000 7,000 13,000

0 0 3 0 0 8,750

15 50 450 2,700 9,100 82,000

0 0 0 2,700 9,100 82,000

0 0 0

0 5 10 0 15.000 30,000 0 0 0

0 8,750 17,500 0 8,750 17,500

Notes * *

Retrofit costs are distributed evenly over 18 year planning period Moderate retrofit assumes bulk mailing or central depot distribution of

* *

*

conservation kits Aggressive retrofit assumes door-to-door distribution of conservation kits Maximum retrofit assumes direct installation of low-flush toilets and low-flow fixtures (two bathrooms per household) Commercial retrofit costs = residential retrofit cost *

Average Daily Use (1991) 3.05 mgd Projected Use (2010) 3.6 mgd 96 Residential 49.0% 96 Commercial 15.0% 96 Institutional 11.0% Number of existing (1990) households

(96 commercial + %institutional) / 96 residential * 2596

3,278


IMPLEMENTING WATER CONSERVATION - (millions of $) -


3.907 4.166 5.636

(million $) 0

(million $) 0

(million $) 0

(million $) 0

1990 Water & Sewer Revenues Est 1993 Water & Sewer Revenue5 Est 2010 Water & Sewer Revenuer Revenue Loss in Y r 20 10

Marginal Loss/Yr




(596) (15%) (25 96 ) 3.907 3.9074 3.9074 4.166 4.1668 4.1668 5.355 4.7914 4.2277

0.282 0.846 1.41

0.016 0.047 0.078

1.004 3.012 5.020

0.103 0.310 0.517

Notes * Discount rate = 7.5% * 1990 revenues estimated from revenues for Clayton and Selma from NC League

of Municipalities survey, 1990 * 2010 water & sewer revenues estimated assuming 1990 water rates and 2010 demands.

APPENDIX C

SUPPLEMENTAL CALCULATION TABLES FOR EVALUATION OF WATER REUSE SCENARIOS

CARY

WTP Expansion Capacity, mgd Cost of Expansion, million $

Table C-1 ESTIMATED SAVINGS FROM DEFERRED CAPITAL COSTS

WATER TREATMENT PLANT EXPANSION - (all flows in mgd)

5

2.5

Without Reuse

1.86 0.01

Avg Day I Max Day

1.83 0.05

Demands in Year 1990 Demands in Year 1995 Demands in Year 201 0

6.2 7.3 10.8

9.6 11.4 16.7


1.55 12

1997.0 Projected Max Day Demand for 15 Yr Plan Period, mgd 17

IDiscount Rate I 7.59 Present Value Cost of Expansion. million $ 1.87 Isavings, million $ I 0 Equivalent Annual Savings, million $ 0

-

With Reuse (reduction) Aggressive I Maximum

Day Day 6.2 9.6

1.55 12

1997.0

1.87 0.00

0.00

11.4 10.7 16.6

1.55 12

1997.1

11.4 10.3 16.0

1.55 12

1997.3

0.00 I 0.00 ~

Notes * Discount rate = 7.5% * Year expansion needed estimated using linear interpolation/extraplation of demands. * Water treatment plant expansion cost assumed to be $0.5/gaI of expanded capacity.

Table C-2 ESTIMATED SAVINGS FROM REDUCED OPERATION & MAINTENANCE COSTS

AT WATER TREATMENT PLANT

lAvg Day Flow in 1990, mgd

CARY

Reuse (Om@) (*I mgd) 6.18 6.18 6.18

. -

Avg Day Flow in 1993, mgd Avg Day Flow in 2010, mgd Savings in Yr 2010

(million $1

I With Reuse (reduction in m

6.873 6.873 6.873 10.8 10.8 10.7

0 0.00 0.01

IWithout I Moderate I Aggressive

Increase in SavingsEr (million $) I 0 I 0.00 0.00



Marginal Operating Cost =

(million $)

(million $)

0 0.00 0.03

0 0.00 0.00 0.2 $/lo00 gal

Maximum ( -5 mgd)

6.18 6.873 10.3

0.04

0.00

0.14

0.01

DURHAM

0.87 0



0.73 0.65 0.14 0.22



15 Yr Plan Period, mnd M T P Expansion Capacity, mgd Cost of Expansion, million $ Discount Rate Present Value Cost of Expansion, million $ Savings, million $ Equivalent Annual Savings, million $

With Reuse (reduction in mgd) Without Moderate Aggressive

Avg I Max Avg 1 Max Avg I Max Reuse (0.90) (1.4)

Day Day Day Day Day Day 25.0 30.2 25.0 30.2 25.0 30.2

1.21 52

201 8.5 0

1.21 52

2021 .o 315

1.21 52

2022.6 508

0 1 0.01 I 0.02

Maximum (5.5)

25.0 30.2 28.2 32.1 38.8

1.21 52

2051.3 2008

0.08 0.79

0.08 Notes * Discount rate = 7.5% * Year expansion needed estimated using linear interpolation/extrapolation of demands. * Water treatment plant expansion cost assumed to be $0.5/gaI of expanded capacity.

Table C-4 ESTIMATED SAVINGS FROM REDUCED OPERATION & MAINTENANCE COSTS

AT WATER TREATMENT PLANT -

_ . -

Avg Day Flow in 1990, mgd Avg Day Flow in 1993, mgd Avg Day Flow in 2010, mgd Annual Savings

(million S) Increase in Savingsnr

(million S) Present Value of Savings

(million $) Equivalent Annual Value

(million $) Marginal Operating Cost =

DURHAM r

With Reuse (reduction) Without Moderate Aggressive Maximum Reuse (0.9) (1.4) (5.5)

25.00 25.00 25.00 25.00 26.89 26.89 26.89 26.89 37.6 36.7 36.2 32.1

0 0.17 0.27 1.04

0 0.01 0.02 0.06

0 0.64 0.93 3.65

0 0.07 0.10 0.39 0.52 $/lo00 gal

OWASA

Existing Treatment Capacity 16.94 201 0

0 Projected Demand for

21 WTP Expansion Capacity, mgd 4.06 Cost of Expansion, million $ 2.03 D is coun t Rate 7.5% Present Value Cost

Year Plant Expansion Needed Reduction in Water Demand (mgy)

15 Yr Plan Period, mgd

of Expansion, million $ 0.59 Savings, million $ 0 Equivalent Annual Savings, million $ 0



201 2.724 144

Demands in Year Demands in Year

2016.65 278

Reus Avg Day

7.5 8.4

11.0

0.49 0.11

Max Day

11.6 12.9 16.9 1.54

0.37 0.23

With Reuse (reduction in mgd) Moderate I Aggressive

Day Day Day Day 7.5 11.6 7.5 11.6 8.4 1 11; I 8.4 1 12.9

10.6 16.3 10.2 15.7 1.54

16.94 I 16.94

I

0.01 I 0.02

Maximum

;:: 1 1.54

16.94 2030.40

' 528

0.14 0.46

0.05

_ .

Avg Day Flow in 1990, mgd

Avg Day Flow in 2010, mgd Avg Day Flow in 1993, mgd

Annual Savings

Increase in Savingsh’r (million S)

(million $)

With Reuse (reduction) Without Moderate Aggressive Maximum Reuse (-4) (-8) (1 5)

7.53 7.53 7.53 7.53 8.05 8.05 8.05 8.05

11 10.6 10.2 9.5

0 0.08 0.15 0.28

0 0.00 0.01 0.02 Present Value of Savings

(million S)


Marginal Operating Cost =

0 0.29 0.53 1 .oo

0 0.03 0.06 0.11 0.52 $/I000 gal

RALEIGH

1.48 62.5

1994.824 144


WATER TREATMENT PLANT EXPANSION (all flows in mgd)

-

1.48 62.5

1994.82 278




17.75 17.75 17.75 17.80 0 0.00 0.00 -0.05

0 0.00 0.00 -0.01

(Reduction in Water Demand (mgy)

Without Reuse

33.4 49.3 42.6 63.0

103.6 1.48 62.5

1994.82 0

Projected Demand for 15 Yr Plan Period, mgd 103

With Reuse (reduction in mgd) Moderate I Aggressive Maximum

(5.3)

33.4 49.3 42.6 63.0 64.7

1.48 62.5

1994.78 528

Notes * Discount rate = 7.5%

- ...


Increase in SavingsNr (million $)


(million S) Equivalent Annual Value

(million $) Marginal Operating Cost = Notes

(million S)

r With Reuse (reduction)

Reuse (0) (.4) (5.3) Without Moderate Aggressive Maximum

33.40 33.40 33.40 33.40 38.89 38.89 38.89 38.89

70 70 69.6 64.7

0 0.00 0.08 1.01

0 0.00 0.00 0.06

0 0.00 0.27 3.52

0 0.00 0.03 0.37 0.52 $/I000 gal

SANFORD

Without Reuse

Avg Max Day Day

Demands in Year 1990 4.2 6.4 Demands in Year 1995 5.3 8.0 Demands in Year 2010 8.4 12.8

Maximum Day Design Factor 1.52

2007.59 Year Plant Expansion Needed Reduction in Water Demand (mgy) 0 Projected Demand for

Existing Treatment Capacity 12



- With Reuse (reduction in mgd)

Moderate Aggressive Maximum

Avg Max Avg Max Avg Max Day Day Day Day Day Day

(0.0) (0.0) (1.3)

4.2 6.4 4.2 6.4 4.2 6.4 5.3 8.0 5.3 8.0 5.3 8.0 8.4 12.8 8.4 12.8 7.1 10.8

1.52 1.52 1.52 12 12 12

2007.593 2007.59 201 6.44 0 9 490

~~ ~

WTP Expansion Capacity, mgd Cost of Expansion,

115 Yr Plan Period, mgd I 17 I 5

million $ Discount Rate

2.5 7.5%


0.87 0.87 0.87 0.46 0 0.00 0.00 0.41

0 0.00 0.00 0.04

_ - -


Increase in Savingsnr



Marginal Operating Cost = Notes

(million $)

(million $)

(million $)

With Reuse (reduction) Without Moderate Aggressive Maximum Reuse (0.0) (0.0) (1.3)

4.20 4.20 4.20 4.20 4.83 4.83 4.83 4.83 8.4 8.4 8.4 7.1

0 0.00 0.00 0.25

0 0.00 0.00 0.01

0 0.00 0.00 0.86

0 0.00 0.00 0.09 0.52 $/lo00 gal

SMITHFIELD duction in mgd)

Aggressive

Avg Max Day Day

(0.0)

3.0 4.8 3.2 5.0 3.6 5.8

1.6 6

2015 13

0.10 0.00

0.00



Maximum

Avg Max Day Day

(0.2)

3.0 4.8 3.2 5.0 3.4 5.4

1.6 6

203 1 85

0.03 0.07

0.01

Demands in Year 1990 Demands in Year 1995

201 0 r Demands in Year

Avg Day 3.0 3.2 3.6

Day Design Factor Existing Treatment Capacity Year Plant Expansion Needed

Max Avg Max Day Day Day

4.8 3.0 4.8 5.0 3.2 5.0 5.8 3.6 5.8

~~

Reduction in Water Demand (mgy) ~-

Projected Demand for 15 Yr Plan Period, mgd WTP Expansion Capacity, mgd Cost of Expansion, million $ Discount Rate Present Value Cost of Expansion, million $ Savings, million $ Equivalent Annual Savings, million $

0.10 0

I With Reuse (I

0.10 0.00

I Moderate (0.0) Without Reuse

1.6 6

201 5

1.6 6

2015 0 1 0

7 1

0 1 0.00

* Discount rate = 7.5%

SMITHFIELD _ .

-


Increase in Savings/Yr (million $)

(million $)

Table (2-12 ESTIMATED SAVINGS FROM REDUCED OPERATION & MAINTENANCE COSTS

AT WATER TREATMENT PLANT - -

Without Reuse

3.00 3.09 3.6

0

0

Moderate (0.0) 3.00

Agress ive Maximum (0.0) (0.2) 3.00 3.00

3.09 3.6 I


(million $)

3.09 3.6 I

0 0.00 0.00 0.86

3.09 2.3

0.00

0.00

0.00

0.00 0.25

0.00 0.00 0.01

Equivalent Annual Value (million $1 0 0.09

MTEinal Operating, Cost = I 0.52 $/1000gal I Notes * Discount rate = 7.5%

..

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