United States

Environmental Protection Office of Water EPA 815-R-98-003

Agency 4607 September 1998

_____________________________________________________________________

Variance Technology

Findings for 

Contaminants Regulated

Before 1996

 
ii

TABLE OF CONTENTS

Table of Contents ii

List of Figures and Tables iv

1. Introduction 2

Section 1.1: Safe Drinking Water Act Implementation 2

Section 1.2: Need for a Small System Technology Requirement 3

Section 1.3: Small System Treatment Technology Requirements 

of the 1996 SDWA 4

Section 1.4: Point-of-Entry and Point-of-Use Treatment Units as 

Compliance Technologies 10

Section 1.5: Format and Content of this Small System Compliance 

Technology List 11

Section 1.6: Stakeholder Involvement 12

Section 1.7: Organization of the Document 12 

2. Two-Stage Screening Process

Section 2.1: Overview 14

Section 2.2: Stage 1: Statutory Screens 14

Section 2.3: Stage 2: Affordability Screens 19

Section 2.4: Summary of Screening Process 23

3. National-Level Affordability

Section 3.1: Introduction 35

Section 3.2: Role of National-Level Affordability Criteria 36

Section 3.3: Unit of Measure for the National-Level Affordability Criteria 37

Section 3.4: Derivation of the National-level Affordability Criteria 38

Section 3.5: National-Level Affordability Criteria 48

4. Affordable Technology Determinations

Section 4.1: Overview 52

Section 4.2: Results of SDWIS Run of Violations 52

Section 4.3: Cost Models 53

Section 4.4: Model Systems 54

Section 4.5: Treatment Cost Estimates 56

5. Summary of Variance Technology Findings for Contaminants 60
iii

Regulated Before 1996

Appendix A: Relevant Parts of Section 1412 of the 1996 SDWA Amendments 62

Appendix B: Relevant Parts of Section 1415 of the 1996 SDWA Amendments 68
iv

LIST OF FIGURES

Figure 1. Small System Requirements: Compliance vs. 

Variance Technologies 7

Figure 2. Affordable Compliance Technologies 9

LIST OF TABLES

Table 1. Regulated Contaminants and their Eligibility for Variance 24

Technologies after Two-Stage Screening Process

Table 2. Residential Consumption at Small Water Systems 41

Table 3. Baseline Household Water Bills by Source Type 42

Table 4. Baseline Household Water Bills 42

Table 5. Baseline Median Household Income 43

Table 6. Summary of Select Consumer Expenditures for 45

All Consumer Units - 1995$

Table 7. National-Level Affordability Criteria 50

Table 8. Design and Average Daily Flows used for Regulations (pre-1996) 55

Table 9. Design and Average Daily Flows used for Affordable 55

Technology Determinations

Table 10. Number of Households by Size Category for POU/POE Options 56

Table 11. Affordable and Other Compliance Technologies in the 57

25 - 500 Size Category
2

1. INTRODUCTION

Section 1.1: Safe Drinking Water Act Implementation

The Safe Drinking Water Act (SDWA) Amendments were signed by the President on August

6, 1996. There are over 70 statutory deadlines in the 1996 SDWA for the Environmental

Protection Agency (EPA). The Amendments contain a challenging set of activities for EPA,

States, Indian tribes, public water systems, and other stakeholders.

Due to the 1996 SDWA’s emphasis on public information and participation, as well as EPA’s

desire to seek a broad range of public input, the stakeholder process that was begun during the

1995 drinking water program redirection effort has been greatly expanded. Many of the 70

statutory deadlines have been grouped into twelve project areas. Each of these areas has a broad

set of stakeholders that will provide information and comments. 

One of the twelve project areas created by the 1996 SDWA is being addressed by EPA’s

Treatment Technology Team. The mission of the Treatment Technology Team is to identify

and/or develop high quality, cost-effective treatment technologies to meet regulation development

and program implementation objectives and deadlines. The short-term goals of this team are to

prepare: (1) by August 6, 1997, the list of technologies that small systems can use to comply with

the Surface Water Treatment Rule (SWTR); (2) by August 6, 1998, the list of technologies that

small systems can use to comply with all of the other pre-1996 National Primary Drinking Water

Regulations (NPDWRs); and (3) by August 6, 1998, the list of variance technologies for small

systems for the appropriate pre-1996 NPDWRs. The long-term goals include the identification

of: (1) small system compliance and variance technologies for all future regulations; (2) best

available technologies (BATs) for larger systems in future regulations; and (3) emerging

technologies that should be evaluated as potential compliance or variance technologies for both

existing and future regulations.

EPA met the first of these short-term goals in August, 1997. A Federal Register notice dated

August 11, 1997 published the compliance technology list for the SWTR (EPA, 1997a). The

notice also announced the availability of a guidance manual entitled “Compliance Technology List

for the Surface Water Treatment Rule” (EPA, 1997b). The guidance manual contained more

detailed information on the list of technologies published in the Federal Register notice.

EPA updated the list of compliance technologies for the SWTR and published the list of

compliance technologies for the total coliform rule in a Federal Register notice on August 6, 1998

(EPA, 1998a). EPA is also publishing an update to the guidance manual that supported the

original SWTR list of compliance technologies. The updated guidance manual is entitled

“Compliance Technology List for the Surface Water Treatment Rule and the Total Coliform

Rule” (EPA, 1998b). This document covers both update of the SWTR list and the compliance

technologies identified for the Total Coliform Rule (TCR). These have been grouped into one

publication as they both address microbial contaminants and their indicators in drinking water. 
3

The list of compliance technologies for the TCR is one of the lists required by Section

1412(b)(4)(E)(iii) of the SDWA.

EPA met both the second and third of the short-term goals in August 1998. A Federal

Register notice dated August 6, 1998 published the list of compliance technologies that systems

can use to comply with all of the other NPDWRs and the findings concerning variance

technologies for the contaminants regulated before 1996. EPA did not, at that time, list any

variance technologies for contaminants regulated before 1996. Guidance manuals were developed

to provide more detail on each of these lists. A document entitled “Small System Compliance

Technology List for the Non-Microbial Contaminants Regulated Before 1996" (EPA, 1998c)

provides more detail on the list of compliance technologies for the non-microbial contaminants

regulated before 1996. The current document has been prepared to describe the procedures that

were used to make the determination, at this time, that there would be no variance technologies

for contaminants regulated before 1996.

Section 1.2: Need for a Small System Technology Requirement

The 1986 SDWA identified a process for setting maximum contaminant levels (MCLs) as

close to the maximum contaminant level goal (MCLG) as is “feasible.” The Act states that the

term “feasible” means feasible with the use of the best technology, treatment techniques and other

means which the Administrator finds, after examination for efficacy under field conditions and not

solely under laboratory conditions, are available (taking cost into consideration) [Section

1412(b)(4)(D)]. The technologies that met this feasibility criterion are called “best available

technologies” (BATs) and are listed in the final regulations. This process is retained in the 1996

SDWA. All of the existing NPDWRs covered in this document were developed using this

process, with the exception of three rules described below.

One regulation covered in this document is the lead and copper rule. The Lead and Copper

Rule requires compliance with a treatment technique rule rather than an MCL. Section

1412(b)(7)(A) of the 1986 SDWA listed the conditions under which a treatment technique could

be promulgated in lieu of an MCL. When these conditions are met, the Act states that “. . . the

Administrator must identify those treatment techniques which, in the Administrator’s judgement,

would prevent known or anticipated adverse effects on the health of persons to the extent

feasible”. The definition of feasible listed above would also apply in the technology

determinations for the Lead and Copper rule.

The SWTR is another treatment technique rule. It is a treatment technique for microbial

contaminants. The structure of this rule is described in detail in the guidance manual entitled

“Small System Compliance Technology List for the Surface Water Treatment Rule and the Total

Coliform Rule” (EPA, 1998b).

There is one other treatment technique rule in the group of contaminants regulated before

1996. Epichlorohydrin and acrylamide are regulated through treatment techniques rather than
4

with a MCL. Unlike the SWTR or the Lead and Copper Rule, the treatment techniques for these

two contaminants are not based on the use of technology to remove or reduce the contaminant

concentration. The treatment technique for these two contaminants requires public water systems

to certify annually, in writing, to the State that when acrylamide or epichlorohydrin are used in

drinking water treatment, the combination of dose and monomer level does not exceed specified

levels. Since technologies are not being utilized for these NPDWRs, neither compliance nor

variance technologies will be listed for these contaminants.

Before the 1996 Amendments, cost assessments for the treatment technology feasibility

determinations were based upon impacts to regional and large metropolitan water systems. This

protocol was established when the SDWA was originally enacted in 1974 (Congressional Record,

1974) and was carried over when the Act was amended in 1986 (Congressional Record, 1986).

The population size categories that EPA has used to make feasibility determinations for regional

and large metropolitan water systems has varied among different regulation packages. The most

common population size categories used were 50,000 - 75,000 people and 100,000 - 500,000

people. The technical demands and costs associated with technologies that are feasible based on

regional and large metropolitan water systems often make these technologies inappropriate for

small systems. The 1996 Amendments attempt to redress this problem by having EPA identify

treatment technologies that are suited for small systems (compliance technologies). The two

compliance technology guidance manuals will help small systems comply with existing NPDWRs. 

Section 1.3: Small System Treatment Technology Requirements of the 1996 SDWA

Since large systems were used as the basis for the feasibility determinations, the existing

BATs for MCLs and the existing treatment techniques may not be appropriate for small systems. 

The 1996 SDWA specifically requires EPA to make technology assessments relevant to the three

categories of small systems respectively for both existing and future regulations, in addition to the

pre-1996 Amendments BAT protocol. The three population-served size categories of small

systems defined by the 1996 SDWA are: 10,000 - 3,301 persons, 3,300 - 501 persons, and 500 -

25 persons.

The 1996 SDWA identifies two classes of technologies for small systems: compliance

technologies and variance technologies. A “compliance technology” may refer to both a

technology or other means that is affordable and that achieves compliance with the MCL and to a

technology or other means that satisfies a treatment technique requirement. Possible compliance

technologies include packaged or modular systems and point-of-entry (POE) or point-of-use

(POU) treatment units [see Section 1412(b)(4)(E)(ii)]. Variance technologies are only specified

for those system size/source water quality combinations for which there are no listed compliance

technologies [Section 1412(b)(15)(A)]. Thus, the listing of a compliance technology for a size

category/source water combination prohibits the listing of variance technologies for that

combination. While variance technologies may not achieve compliance with the MCL or

treatment technique requirement, they must achieve the maximum reduction or inactivation

efficiency that is affordable considering the size of the system and the quality of the source water. 
5

Variance technologies must also achieve a level of contaminant reduction that is protective of

public health [Section 1412(b)(15)(B)].

The variance procedure for small systems has been significantly revised under the 1996

SDWA. Under the 1986 SDWA, systems were required to install a technology before applying

for a variance; if they were unable to meet the MCL, they could then apply for a variance. The

1996 Amendments have given the variance option additional flexibility in that variances can be

applied for and granted before the variance technology is installed, thus ensuring that the system

will have a variance before it invests in treatment. Under the 1996 SDWA, there is a new

procedure available for small systems (systems serving less than 10,000): the “small system

variance”. The difference between a regular variance and a small system variance is the basis for

the feasibility (technical and affordability) determination. For the former, large systems are the

basis; for the latter, small systems are the basis. If there are no affordable compliance

technologies listed by the EPA for a small system size category/source water quality combination,

then the system may apply for a small system variance. One of the criteria for obtaining a small

system variance is that the system must install a variance technology listed for that size

category/source water quality combination [Section 1415(e)(2)(A)]. A small system variance may

only be obtained if alternate source, treatment, and restructuring options are unaffordable at the

system-level.

There are some additional requirements for small system variances that affect the listing of

variance technologies. Small system variances are not available for any MCL or treatment

technique for a contaminant with respect to which a national primary drinking water regulation

was promulgated prior to January 1, 1986 [Section 1415(e)(6)(A)]. The final Variance and

Exemption Rule provides EPA’s interpretation of this requirement (EPA, 1998d). Small system

variances would not be available for those contaminants with existing MCLs that were

promulgated prior to January 1, 1986. Small system variances would not be available if the pre1986 MCL was retained or raised. Small system variance would only be available if the pre-1986

MCL was lowered (could apply to updates of the existing arsenic and radionuclides MCLs if the

pre-1986 MCLs are lowered). If the Agency revises a pre-1986 MCL and makes it more

stringent, there would be an additional restriction of the availability of small system variances. If

the variance option was available, the finished water quality could not exceed the pre-1986 MCL. 

Nor are small system variances available for a NPDWR for a microbial contaminant (including a

bacterium, virus, or other organism) or an indicator or treatment technique for a microbial

contaminant [Section 1415(e)(6)(B)]. The sole purpose of the listing of variance technologies is

to enable small systems to obtain a small system variance. Therefore, when these small system

variances are not available under the SDWA, variance technologies were not specified for those

contaminants.

The process for identifying compliance and variance technologies for future regulations was

summarized in the preceding paragraphs. The language in the 1996 SDWA Amendments is

different for the existing regulations. There are two mandatory lists of compliance technologies

that were developed for the existing rules. By August 6, 1997, the Administrator was required to
6

list technologies that meet the SWTR for each of the three size categories [Section

1412(b)(4)(E)(v)]. By August 6, 1998, after consultation with the States, the Administrator was

required to issue a list of technologies that achieve compliance with the MCLs or treatment

technique requirements for other existing NPDWRs. By August 6, 1998, after consultation with

the States, the Administrator was required to issue guidance or regulations for variance

technologies for the existing NPDWRs for which a small system variance can be granted. Figure

1 summarizes the requirements for compliance and variance technologies and differentiates

between existing and future regulations.
7

FIGURE 1

SMALL SYSTEM REQUIREMENTS

COMPLIANCE VS. VARIANCE TECHNOLOGIES

COMPLIANCE

TECHNOLOGY

VARIANCE

TECHNOLOGY

EXISTING

REGULATIONS:

 Meet affordable

 technology criteria

Not Explicitly Required Inherently Required

 Source Water Quality GOOD POOR

 Endpoint MCL Maximum Reduction

that is Affordable

 Health Requirements

 Separate from MCL

NONE Must be protective of

public health

FUTURE

REGULATIONS:

 Meet affordable

 technology criteria

Required Required

 Source Water Quality GOOD POOR

 Endpoint MCL Maximum Reduction

that is Affordable

 Health Requirements

 Separate from MCL

NONE Must be protective of

public health
8

The two major concerns regarding technologies for small systems are affordability and

technical complexity: per household costs tend to be higher for the smaller system customers for

most central treatment technologies, leading to many cases where small systems simply cannot

afford to install a prescribed technology, and small systems often do not have access to welltrained water system operators. Although the statute is silent concerning whether small system

compliance technologies for existing regulations should be affordable, EPA believes that the

better approach under the statute is that affordability should be evaluated for future regulations

and existing regulations where the statute allows variance technologies. If the candidate

technologies are not evaluated against an affordable technology criterion, then compliance

technologies would automatically exist for all of the existing regulations regardless of the source

water quality. The existing best available technologies (BATs) or treatment techniques would

become the compliance technologies for small systems, which was the case prior to the 1996

Amendments. EPA does not believe that result to be what Congress intended. As a result, EPA

evaluated small system technologies against an affordable technology criterion for those existing

regulations where small system variances or variance technologies are not prohibited by the

SDWA.

The flow chart in Figure 2 shows the role of the affordable technology criteria in the

treatment technology arena. The primary function of the criteria is to determine whether a system

of a given size/source water quality combination should proceed down the compliance or variance

technology pathway. The secondary function is to define the universe of technologies within the

compliance or variance technology pathway. These affordable technology criteria are different

from the affordability criteria to be used by States in granting small system variances under

Section 1415(e). The criteria used by States will be applicable to individual systems (“systemlevel affordability criteria”). Options that States can use for system-level affordability criteria

were developed in the Small System National Drinking Water Advisory Council (NDWAC)

Working Group process and are available in “Information for States on Developing Affordability

Criteria for Drinking Water” (EPA, 1998e). This document was published on February 4, 1998

can be downloaded at http://www.epq.gov/OGWDW/smallsys/afford.html. In contrast, the

affordable technology criteria developed under Section 1412(b)(4) can be viewed as “nationallevel affordability criteria”. Technologies that meet the national-level criteria may not be

affordable for a particular system within the size category. The role of the system-level

affordability criteria is illustrated in Figure 2 as well.

For those existing regulations where the SDWA prohibits small system variances or variance

technologies, the candidate compliance technologies will not be evaluated against an affordable

technology criterion. There are two statutory prohibitions on small system variances and one

prohibition on variance technologies. As previously mentioned, small system variances are not

available for any NPDWR for a microbial contaminant (or indicator). Variance technologies were

not identified for any of the six microbial contaminants that are currently regulated. Small system

variances are also not available for any MCL or treatment technique with respect to which a

NPDWR was promulgated prior to January 1, 1986. Variance technologies were not identified

for any of the 12 contaminants where the pre-1986 MCL has 
9

System Out

of Compliance

Affordable

Compliance

Technology?

Can System

afford Treatment

Alt. Source or

Restructuring?

Can

system afford

a compliance

technology?

Can System

Restructure

or afford Alt

Source?

Implement

Compliance

Technology

Implement

Treatment,

Alt Source or

Restructuring

Implement

Affordable

variance

technology

FIGURE 2

AFFORDABLE COMPLIANCE TECHNOLOGIES*

Has

exemption

period run

out?

Obtain Small

System Variance

Exemption

Process (State

sets schedule

for compliance)

Is

Restructuring

practicable?

*NOTE: This approach covers the regulations that pass all of the

screening criteria for variance technologies.

Are

Exemptions

Available

YES NO

YES NO

YES

NO

NO

YES

YES

YES

YES

YES RS

NO

NO

YES

NO

NO
10

been retained or raised. The statutory prohibition on variance technologies is found in Section

1412(b)(15)(B) of the SDWA. The Administrator shall not identify any variance technology

under this paragraph, unless the Administrator has determined, considering the quality of the

source water to be treated and the expected useful life of the technology, that the variance

technology is protective of public health. For 19 contaminants, it was determined that, in order to

be protective of public health, the MCL had to be met. Since the MCL is the treatment standard,

compliance technologies are the only alternative. These statutory screens for variance

technologies are discussed in more detail in Chapter 2.

Section 1.4: Format of Variance Technology Lists

Section 1412(b)(15)(D) states that the variance technology list for the contaminants

regulated before 1996 can be issued either through guidance or regulations. The three key

requirements of Section 1412(b)(15)(D) on the list format are as follows: “Not later than 2 years

after the date of enactment of this paragraph and after consultation with the States, the

Administrator shall issue guidance or regulations under subparagraph (A) for each national

primary drinking water regulation promulgated prior to the date of enactment of this paragraph

for which a variance may be granted under section 1415(e). The Administrator may, at any time

after a national primary drinking water regulation has been promulgated, issue guidance or

regulations describing additional variance technologies. The Administrator shall, not less often

than every 7 years, or upon receipt of a petition supported by substantial information, review

variance technologies identified under this paragraph.”

EPA has chosen the guidance format for a number of reasons. Because this is the first time

that EPA has undertaken the variance technology analysis required under the amended SDWA

(which includes new findings concerning “affordability” and “protectiveness”) and given the

relatively short time for development of this analysis, EPA considers the methodology described

here and the resulting finding of no variance technologies to be an initial screening effort, rather

than a final determination of any kind. In addition, by enabling EPA to list variance technologies

through guidance rather than specifying them by regulation, the statute specifically contemplates

that this analysis (and any resulting list) would be subject to revision, based on new information

and petitions from interested parties.

In summary, EPA has chosen to list the variance technology findings through a Federal

Register notice and a guidance document because regulation development is unnecessary and

could considerably delay publication of the criteria used in this screening effort. Issuing the

findings without rule-making allows EPA to meet the statutory deadline and to disseminate the

criteria used to make the “affordability” and “protectiveness” findings. It is much easier and faster

to update a guidance rather than a rule to address pertinent comments received in petitions from

interested parties.
11

Section 1.5: Content of Variance Technology Lists

The SDWA does specify some content requirements for variance technologies. Section

1412(b)(15)(C) states that “The Administrator shall include in the guidance or regulations

identifying variance technologies under this paragraph any assumptions supporting the public

health determination referred to in subparagraph (B), where such assumptions concern the public

water system to which the technology may be applied, or its source waters. The Administrator

shall provide any assumptions used in determining affordability, taking into consideration the

number of persons served by such systems. The Administrator shall provide as much reliable

information as practicable on performance, effectiveness, limitations, costs, and other relevant

factors including the applicability of variance technology to water from surface and underground

sources.” EPA interprets this provision as requiring the list of variance technologies to include

information regarding “protectiveness”, “affordability”, and “performance and effectiveness” of

the listed technologies.

The “protectiveness” criteria are discussed briefly in Chapter 2. The “affordability” criteria

are discussed in detail in Chapter 3. The “performance and effectiveness” criteria are described in

the final Variance and Exemption Rule (EPA, 1998d). When variance technologies are identified,

EPA will provide accompanying guidance. The guidance will identify the typical removal

efficiency achieved by each variance technology, considering the overall capabilities of the

treatment process and the source water on which the technology would typically be applied. The

guidance will also discuss source water characteristics that can adversely affect the removal of the

contaminant by the process. The guidance will discuss the cost estimate for the technology that

was used to determine if the technology was affordable. The guidance will discuss site-specific

factors that can affect technology costs as well as the performance and effectiveness of the

technology.

When variance technologies are identified, the list will not be product-specific. Variance

technologies will be very similar to compliance technologies in that a general technology

designation will be used. However, the guidance will contain more detail on treatment

performance and costs than the compliance technology guidances. The variance technology lists

will not be product-specific because EPA’s Office of Ground Water and Drinking Water does not

have the resources to review each product for each potential application; nor does EPA feel it

would be appropriate to do so.

Information on specific products will be available through another mechanism. EPA’s Office

of Research and Development has a pilot project under the Environmental Technology

Verification (ETV) Program to provide treatment system purchasers with performance data from

independent third parties. The EPA and National Sanitation Foundation International (NSF) are

cooperatively organizing and conducting this pilot project to allow for verification testing of

packaged drinking water treatment systems for meeting community and commercial needs. This

pilot project includes development of verification protocols and test plans, independent testing

and validation of packaged equipment, conveying and supporting government/industry
12

partnerships to obtain credible cost and performance data, and preparation of product verification

reports for wide-spread distribution. 

Section 1.6: Stakeholder Involvement

EPA held a stakeholder meeting on May 18 and 19, 1998. Approximately 50 people

registered and participated in the meeting. Key stakeholders included States, water systems, and

equipment manufacturers. Representatives from nine States were present at the meeting (either at

the meeting or on conference lines) and several others received the material that was sent out

prior to the meeting for review. A draft of the “National-Level Affordability Criteria Under the

1996 Amendments to the Safe Drinking Water Act” (EPA, 1998f) was sent out prior to the

meeting. 

There were two major topics related to variance technology findings that were discussed in

the stakeholder meeting. The first was the two-stage screening process that is discussed in

Chapter 2. The second is the national-level affordability criteria that are discussed in Chapter 3. 

Stakeholder comments will be discussed in each of these chapters rather than in Chapter 1.

Section 1.7: Organization of the Document

This document is organized into several chapters describing the variance technology findings

for the contaminants regulated before 1996. Chapter 1 discusses the requirements of the 1996

SDWA and the overall approach EPA is following to meet those requirements. Chapter 2

discusses the two-stage screening process that was used to identify those contaminants that would

have technology costs compared against the national-level affordability criteria. Chapter 3

summarizes the derivation of the national-level affordability criteria. Chapter 4 describes the

affordable technology determinations and how treatment costs are compared against the nationallevel affordability criteria. Chapter 5 contains a summary of the variance technology findings for

contaminants regulated before 1996.
13

REFERENCES

Congressional Record. 1974. House of Representatives 93-1185 at 18. The 93rd Congress,

Second Session. 13. Microfilm #H503-28.

Congressional Record. 1986. Vol. 132. 99th Congress, Second Session. No. 69. May 21,

1986. P. S6287. Statement of Senator Durenberger. [132 Cong. Reg.]

USEPA. 1997a. Federal Register. 62(154): 42986. August 11, 1987.

USEPA. 1997b. Small System Compliance Technology List for the Surface Water Treatment

Rule. EPA-815-R-97-002. Washington D.C.: Office of Water. August 1997.

USEPA. 1998a. Federal Register. 63(151): 42032. August 6, 1998.

USEPA. 1998b. Small System Compliance Technology List for the Surface Water Treatment

Rule and Total Coliform Rule. EPA-815-R-98-001. Washington D.C.: Office of Water. 

September 1998.

USEPA. 1998c. Small System Compliance Technology List for the Non-Microbial Contaminants

Regulated Before 1996. EPA-815-R-98-002. Washington, D.C.: Office of Water. September

1998.

USEPA. 1998d. Federal Register. 63(157): 43834. August 14, 1998.

USEPA. 1998e. Information for States on Developing Affordability Criteria for Drinking Water. 

EPA-816-R-98-002. Washington, D.C.: EPA Office of Water. February, 1998.

USEPA. 1998f. National-Level Affordability Criteria Under the 1996 Amendments to the Safe

Drinking Water Act. Prepared by International Consultants, Inc., Hagler Bailly Services, Inc. and

Janice A. Beecher, Ph.D. for the EPA. August 1998.
14

2. TWO-STAGE SCREENING PROCESS

Section 2.1: Overview

Chapter 1 discussed the SDWA requirements related to compliance and variance

technologies. Compliance and variance technologies are mutually exclusive for a system size

category/source water quality combination. Since compliance technologies were provided for all

of the regulated contaminants and all classes of small systems, variance technologies will not, at

this time, be listed for any existing NPDWR.

There are NPDWRs for 80 contaminants. The existing regulations can be divided into six

categories: 6 microbial contaminants, 1 disinfection by-product, 21 volatile organic contaminants

(VOCs), 32 synthetic organic contaminants (SOCs), 17 inorganic contaminants (IOCs), and 3

radionuclides. This chapter looks at the screening process that was used to identify the

contaminants that would need to have technology costs compared against the national-level

affordability criteria. Three of the 80 regulated contaminants were removed prior to the twostage screening process: total trihalomethanes, acrylamide, and epichlorohydrin.

The current total trihalomethane regulation only applies to systems serving greater than

10,000 people. Therefore, small systems do not have to meet the existing standard, so neither

compliance nor variance technologies will be listed. Compliance technologies and variance

technologies (if appropriate) will be listed when the standard is revised and applied to small

systems. 

Acrylamide and epichlorohydrin are compounds associated with chemical additives used in

drinking water treatment. These contaminants are regulated through a treatment technique that

requires a certification that the product of the dose and monomer concentration will not exceed

certain levels. Treatment technology is not installed to remove the contaminants under this

treatment technique. As such, there are no compliance or variance technologies for either of these

two contaminants.

As described above, one disinfection by-product and two of the SOCs were removed prior to

the two-stage screening process. The first stage of the two-stage screening process is an

evaluation of statutory screens. The second stage of the process involved the use of affordability

and occurrence screens. The remaining 77 contaminants proceeded through this two-stage

screening process.

Section 2.2: Stage One of the Screening Process: Statutory Screens

The first stage of the screening process was an evaluation of statutory screens that limit the

availability of small system variances or variance technologies. There are three statutory screens. 

The first two prohibit small system variances. The sole purpose of the listing of variance

technologies is to enable small systems to obtain a small system variance. Therefore, when these
15

small system variances are not available under the SDWA, variance technologies will not be

specified. The third statutory screen is a restriction on the listing of variance technologies.

Section 2.2.1: Statutory Screens: Microbial Contaminants

The first statutory screen is in Section 1415(e)(6)(B) of the SDWA. Small system variances

are not available for any microbial contaminant (including a bacterium, virus, or other organism)

or an indicator or treatment technique for a microbial contaminant. This screen removes 6

contaminants from consideration for variance technologies. These contaminants are: Giardia

lamblia, Legionella, heterotrophic plate count bacteria, turbidity, viruses and total coliforms. 

Giardia lamblia, Legionella, and viruses are microbial contaminants. Heterotrophic plate count

and total coliforms are indicators for microbial contaminants. Turbidity is used to measure the

effectiveness of filtration in removing microbial contaminants. Filtration is one of the treatment

techniques identified in the surface water treatment rule.

Section 2.2.2: Statutory Screens: Contaminants with NPDWRs Promulgated before 1986

The second statutory screen is in Section 1415(e)(6)(A) of the SDWA. Small system

variances are not available for any MCL or treatment technique with respect to which a NPDWR

was promulgated prior to January 1, 1986. The proposed and final Variance and Exemption Rule

describes EPA’s interpretation of this section of the SDWA [(EPA, 1998a) and (EPA, 1998b)]. 

EPA has interpreted this prohibition to apply to the level at which any contaminant was regulated

before 1986. EPA surmised that the intent behind this provision was to prohibit a public water

system from obtaining a variance for a contaminant for which compliance should have been

achieved long ago. Therefore, small system variances are not be available for those contaminants

where the pre-1986 MCL has been retained or raised. However, if EPA revises a pre-1986 level

and makes it more stringent (i.e., makes the MCL lower), then a variance might be available for

that contaminant, but only up to the pre-1986 MCL. 

The second statutory screen removes 12 contaminants from consideration. These

contaminants are: arsenic, beta particle and photon activity, gross alpha particle activity, radium

226 and 228 combined, 2,4,5-TP, endrin, fluoride, barium, chromium, mercury, nitrate, and

selenium. The pre-1986 MCLs were not revised for arsenic and the three radionuclide

contaminants. Revisions to these rules are expected in the future. If the pre-1986 MCL is

lowered, small system variances (and variance technologies) for those contaminants would no

longer be prohibited by this section of the SDWA. A small system variance would be available for

those contaminants, but only up to the pre-1986 MCL. Six of the contaminants had their pre1986 MCL raised when the MCL was revised between 1986 and 1996. These six contaminants

are: 2,4,5-TP, endrin, fluoride, barium, chromium, and selenium. Two of the contaminants had

their pre-1986 MCLs retained when the MCL was re-evaluated between 1986 and 1996: mercury

and nitrate.
16

Section 2.2.3: Statutory Screens: Protective of Public Health Requirement

The final statutory screen is in Section 1412(b)(15)(B) of the SDWA. “The Administrator

shall not identify any variance technology under this paragraph, unless the Administrator has

determined, considering the quality of the source water to be treated and the expected useful life

of the technology, that the variance technology is protective of public health.” For the two-stage

screening process, a surrogate was used for the “protective of public health” levels. The

procedures for determining an unreasonable risk to health (URTH) were used as the surrogate for

“protective of public health” levels. URTH is a concept that was retained in the 1996 SDWA

from the 1986 SDWA and it applies to the granting of variances under Section 1415(a) or

exemptions. In order to grant a variance under Section 1415(a) or an exemption, the State must

find that the variance or exemption will not result in an unreasonable risk to health. The variances

under Section 1415(a) are different from the small system variances under Section 1415(e).

The procedures for determining URTH values are described in “Toxicological Basis for

Drinking Water: Unreasonable Risk to Health Values” (Orme-Zavaleta, 1992). The procedures in

this paper have been used with the data in “Drinking Water Regulations and Health Advisories”

(EPA, 1996) to derive URTH values for the regulated contaminants that passed through the first

two statutory screens. 

The toxicity or pathogenicity of a contaminant is considered in developing the maximum

contaminant level goal (MCLG), a non-enforceable health goal. As previously discussed, the

MCL is set as close to the MCLG as feasible, taking such factors as analytical capability, cost of

treatment, and treatment availability into account. For most non-carcinogens, the MCL will equal

the MCLG. For carcinogens and a very few non-carcinogens, the MCL is higher than the MCLG

and is based on feasibility. The MCLGs for carcinogens were set at zero and the MCLs had to be

set at a higher level since it is not feasible to achieve a level of zero.

For the regulated contaminants, EPA considered two mechanisms for producing a toxic or

pathogenic response -- threshold or non-threshold. For a threshold response, exposure at or

above the threshold level can result in a toxic outcome, whereas for non-threshold response,

exposure at any level except zero can theoretically lead to a toxic outcome. In general, the health

effects for non-carcinogens utilized a threshold approach and the carcinogens utilized a nonthreshold approach.

For the threshold (non-carcinogenic) contaminants, the MCLG represents a level that is

protective of health effects for up to a lifetime exposure. A lifetime is assumed to be 70 years for

this analysis. One of the key components to determining an URTH value for drinking water

contaminants is the determination of short-term acceptable risk levels. Under the procedures

outlined in the article, a short-term acceptable risk level is defined as the concentration above the

MCL that would not pose a health risk for a short period of time (e.g., up to 7 years, or 10% of

an individual’s lifetime). A 7-year period is recommended for both non-carcinogenic and

carcinogenic contaminants. The URTH values were used as a surrogate for the protective of
17

public health requirement of Section 1412(b)(15)(B) because the URTH values are based on a

short-term exposure of up to 7 years. Section 1412(b)(15)(B) requires that the variance

technology be protective of public health for the expected useful life of the technology. Most

technologies will have expected useful lives greater than 7 years, so a concentration that is

protective of public health would need to be less than or equal to the URTH value. The expected

useful life for most treatment technologies for small systems was assumed to be 20 years. There

is an ongoing project to better define the expected useful life for each type of technology. Once

this work is completed, it will be utilized in the development of “protective of public health”

ranges when variance technologies are identified. 

Since the concentration that is protective of public health needs to be less than or equal to the

URTH value, contaminants with little or no margin between the MCL and the URTH value could

be removed from consideration for variance technologies. For 19 contaminants, the derived

URTH value was equal to the MCL or very close to the MCL. For these 19 contaminants, it was

determined that in order to be protective of public health, the MCL had to be met. Since the

MCL is the treatment standard, compliance technologies are the only alternative. Variance

technologies are not listed for these contaminants. The process used to derive the URTH values

for all of the contaminants that passed through the first two statutory screens is described in the

following paragraphs.

In developing a short-term acceptable risk level, the toxicity of each contaminant needs to be

evaluated individually. This was done by considering any available risk assessment conducted for

each contaminant (EPA, 1996). Both cancer and non-cancer hazards were considered in the

evaluation of the risk assessments. The type of available risk assessment values used for

developing the short-term acceptable risk levels include: a) the maximum contaminant level goal

(MCLG) and the MCL; b) the drinking water equivalent level (DWEL), which represents a

lifetime exposure concentration protective of adverse, non-cancer health effects, that assumes all

of the exposure to a contaminant is from a drinking water source; c) the longer-term health

advisory for a child; d) the EPA cancer classification and MCLG category I, II, or III; e) the 10-4

excess cancer risk level; and f) the MCLG multiplied by a factor of 1 to 10 for contaminants with

limited evidence of carcinogenicity via ingestion. Rather than describe all of the procedures in

the article on deriving URTH values, this guidance will cover those that were used for the 19

contaminants that were removed from consideration for variance technologies.

The MCLGs for three contaminants were based on acute endpoints of toxicity. For these

contaminants, the MCL is used as the benchmark for the short-term acceptable risk level. These

three contaminants are: copper, nitrite, and nitrate plus nitrite. Copper is also discussed later in

the affordability screen section along with lead.

There are 16 contaminants whose MCLGs were based on chronic health effects. The

MCLGs for 12 of these 16 contaminants were based on carcinogenic risks. The MCLGs for the

remaining 4 contaminants were based on non-carcinogenic risks.
18

For the 12 contaminants whose MCLGs were based on carcinogenic risks, the 10-4 excess

cancer risk level was used to derive the URTH value. When EPA set MCLs for carcinogenic

contaminants, the excess risk of cancer associated with the MCL was within an acceptable range

of 1 cancer in ten thousand people (10-4) to 1 cancer in one million people (10-6). These cancer

risks were estimated for both known and probable human carcinogens via ingestion. For

carcinogens where the MCL is set at a concentration less than the 10-4 risk level, the 10-4 excess

cancer risk level may be used as the short-term acceptable risk level for URTH if this value does

not exceed the DWEL or the longer-term health advisory for a child. The lower of these values is

recommended as the short-term acceptable risk level for URTH. For the 12 contaminants, the

lowest value was the 10-4 excess cancer risk level. For eight of the contaminants, the 10-4 excess

cancer risk level was equivalent to the MCL. These contaminants are: vinyl chloride, styrene,

ethylene dibromide, PCBs, toxaphene, benzo(a)pyrene, 2,3,7,8-TCDD (dioxin), and beryllium. 

For four of the contaminants, the 10-4 excess cancer risk level was less than or equal to 1 Fg/L

above the MCL. Since the URTH value was approximately equivalent to the MCL and since the

protective of public health concentration would likely need to be closer to the MCL, the MCL

was selected as being the protective of public health concentration for these contaminants. In

addition, the cost difference between meeting the MCL and a concentration less than 1 Fg/L

above the MCL would be negligible for systems that had to install treatment. These contaminants

are chlordane, heptachlor, heptachlor epoxide, and hexachlorobenzene.

The remaining four contaminants showed no evidence of carcinogenicity via ingestion. The

MCLGs are based on non-carcinogenic risks. For these contaminants, the longer-term health

advisory for a child is recommended for the short-term acceptable risk level. Longer-term health

advisories are derived from subchronic studies that involve exposures for up to 10% of the

animals lifetime. Since the MCL is based on a lifetime exposure of 70 years, the longer-term

health advisory would be appropriate for an exposure period of up to 7 years. The longer-term

health advisory is calculated for both a child and an adult. For a child, adjustments are made for

the child’s body weight and average daily water consumption. Alternatively, the DWEL is

recommended for the short-term acceptable risk level when data to calculate a longer-term health

advisory are not available or if the DWEL provides a lower value than the longer-term health

advisory. 

The longer-term health advisory for the child is equivalent to the MCL for three of the four

contaminants. There contaminants are: oxamyl, cadmium, and cyanide. For thallium, the DWEL

is approximately equal to the MCL (DWEL = 2.3 Fg/L and the MCL = 2 Fg/L). Thallium is

unique in that it is the only non-carcinogenic contaminant where the MCL does not equal the

MCLG. The MCLG for thallium is 0.5 Fg/L. That is why the DWEL is approximately equal to

the MCL. Since the URTH value was approximately equivalent to the MCL and since the

protective of public health concentration would likely need to be closer to the MCL, the MCL

was selected as being the protective of public health concentration for thallium. In addition, the

cost difference between meeting the MCL and a concentration less than 1 Fg/L above the MCL

would be negligible for systems that had to install treatment.
19

EPA is currently evaluating the procedures outlined in the "Toxicological Basis for Drinking

Water: Unreasonable Risk to Health Values" paper (Orme-Zaveleta, 1992). EPA will issue a

revised guidance manual for determining URTH as a result of this review process. The URTH

values listed in Table 1 will be modified or recalculated based on revisions to the procedures for

determining URTH values. The 19 contaminants removed by this screen will be examined using

the new procedures to determine if there is a level above the MCL that may be protective of

public health for the expected useful life of a technology.

Variance technologies were not listed for 37 contaminants based on the statutory screens

described in this section. The remaining 40 contaminants proceeded into the second stage of the

screening process.

Section 2.3: Stage Two of the Screening Process: Affordability Screens

 The second stage of the screening process involved affordability screens and evaluations. 

There were three affordability screens used in this stage of the process. The first screen examined

those contaminants that had a low-cost technology option available. The next screen used

occurrence data to make projections about the likelihood of MCL violations. The third screen

examined violation data for contaminants.

Section 2.3.1: Affordability Screens: Low-Cost Compliance Technology

Since Section 1412(b)(15)(A) of the SDWA authorizes a variance technology listing only

where compliance technologies are unaffordable for any category of small systems, any

contaminant that has a low-cost compliance technology will not have variance technologies. 

When a low-cost compliance technology that meets the national-level affordability criteria can be

identified for a system size/source water quality combination, variance technologies are not

available. For this screen, the best available technologies (BATs) listed in the regulations were

examined and technologies that imposed an increase of less than $300/household/year for each

size category were identified to screen for affordability. The “National-Level Affordability

Criteria Under the 1996 Amendments to the Safe Drinking Water Act” report (EPA, 1998c)

identified options for national-level affordability criteria that ranged from 1.5% to 3% of the

median household income. The cost increase associated with the lowest option (1.5%) translated

into an increase of $270/household/year, which was rounded up to $300/household/year for this

screening analysis in the 25 - 500 size category. For the larger two size categories,

$250/household/year was used for this screen. All of the technology costs were later verified

against the national-level affordability criteria that were selected. The national-level affordability

criteria are discussed in detail in Chapter 3. 

The BATs were examined for each of the remaining 40 contaminants. Four technologies

were identified as being low-cost technologies for each of the three size categories. These

technologies that met this screening criterion were aeration, aeration plus chlorination, corrosion

control, and oxidation. Diffused aeration and chlorine oxidation technologies can be
20

characterized as requiring basic operator skill with low monitoring requirements, low capital cost 

and low relative operating cost [see “Safe Water from Every Tap” (NRC, 1997)]. Corrosion

control using chemical feeders can be characterized as requiring basic operator skill with low

monitoring requirements, low capital costs and medium relative operating cost (NRC, 1997). 

Thus, these technologies represent the most basic options available to systems to reduce

contaminant concentrations.

The cost for diffused aeration was estimated to be below $150/household/year for the 25 -

500 category. The cost for diffused aeration plus chlorination were estimated to be below

$250/household/year for the 25 - 500 category. For this analysis, costs were done for a

centralized system (one well) and a decentralized system (two wells). The higher costs for the

decentralized scenario were towards the higher end of the ranges listed above. In the higher size

categories, the costs estimated for diffused aeration and diffused aeration plus chlorination were

below $100/household/year. These cost estimates were verified against the national-level

affordability criteria described in Chapter 3 to ensure that there was an affordable compliance

technology. In addition, these cost estimates were compared against the national-level

affordability criteria to identify affordable compliance technologies. The affordable compliance

technologies for VOCs are discussed in “Small System Compliance Technology List 

for the Non-Microbial Contaminants Regulated Before 1996” (EPA, 1998d). Variance

technologies were not available for all of the VOCs based on the affordability of aeration

technologies. There are 21 regulated VOCs. Variance technologies were already not available

for styrene and vinyl chloride because of the statutory screen that requires the variance technology

to be protective of public health. The other 19 VOCs removed by this screen are: benzene,

carbon tetrachloride, chlorobenzene, cis-1,2-dichlorobenzene, 1,2-dichloroethane, 1,1-

dichloroethylene, dichloromethane, 1,2-dichloropropane, ethylbenzene, o-dichlorobenzene, pdichlorobenzene, tetrachloroethylene, toluene, trans-1,2-dichloroethylene, 1,2,4-trichlorobenzene,

1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, and xylenes (total). In addition,

there are three SOCs that can be effectively removed by aeration. These SOCs are:

dibromochloropropane, di(2-ethylhexyl) adipate, and hexachlorocyclopentadiene. The

affordability of aeration technologies removed 22 contaminants from consideration.

The listed BAT for glyphosate is oxidation. The oxidation can be accomplished through the

use of either chlorination or ozonation. The costs for chlorination were estimated to be below

$100/household/year for all three size categories. The costs for ozonation were higher than

chlorination, especially in the smallest size category. Since there is an affordable compliance

technology for glyphosate, variance technologies will not be available. The affordability of the

chlorine oxidation removes glyphosate from consideration of variance technologies.

The final contaminant removed from consideration for variance technologies by this screen is

lead. Corrosion control is listed as one of the treatment techniques for both lead and copper

under the lead and copper rule. The lead and copper rule lists three general classes of corrosion

control treatments: alkalinity and pH adjustment, calcium hardness adjustment, and corrosion

inhibitors. The following chemical feed systems can be used for the alkalinity and pH adjustment
21

and the calcium hardness adjustment options: sodium hydroxide, lime, sodium bicarbonate, and

soda ash. The costs for each of these corrosion control feed systems is less than

$100/household/year in all three size categories. The lead and copper rule identifies two types of

corrosion control inhibitors: orthophosphate-based and silicate-based. Annual costs were

estimated for a zinc orthophosphate inhibitor feed system. These costs were also below

$100/household/year in all three size categories. The lead and copper rule envisions that some

systems might need two chemical feed systems for their optimal corrosion control process. The

costs for these combinations will be well under $200/household/year. Since the corrosion control

treatments meet the affordability screen, variance technologies would not be available for lead. 

Variance technologies were already not available for copper because of the statutory screen that

requires the variance technology to be protective of public health. Otherwise, copper would be

removed by this screen.

The technologies evaluated for this screen represent simple, low-cost options for compliance

with the rules for 24 contaminants. In addition, aeration and oxidation are very efficient processes

for VOCs and glyphosate, respectively. A variance technology may not achieve compliance with

the MCL or treatment requirement of a regulation, but shall achieve the maximum reduction or

inactivation frequency that is affordable considering the size of the system and the quality of the

source water. Since removal efficiency is not a driving factor in the costs of these technologies, a

contaminant endpoint above the MCL would not significantly reduce household water bills. Thus,

the goal for these systems should be compliance with the standard using one of the identified

compliance technologies.

Section 2.3.2: Affordability Screens: Contaminant Occurrence - No Projected Violations

After the first affordability screen, 16 contaminants remained eligible for consideration for

variance technologies. The next affordability screen involved an evaluation of compliance

monitoring data and National Pesticide Survey data for the remaining 16 contaminants (14

pesticides). The other two contaminants, antimony and asbestos, are inorganic contaminants

(IOCs). EPA assumed that if there were no violations, existing technologies for compliance have

been affordable and variance technologies were not available for these contaminants.

One of the sources of occurrence data used for this screen was the National Pesticide Survey. 

The National Pesticide Survey was conducted from April 1988 through February 1990. Drinking

water wells throughout the country were analyzed for 126 pesticides and pesticide degradates,

plus nitrate. During the survey, 783 rural domestic wells and 566 community water system wells

were sampled. Thirteen of the 14 pesticides were included in the National Pesticide Survey. Only

endothall was not included. For each pesticide in the survey, a minimum reporting level (MRL)

was established. The MRL was the minimum concentration at which a pesticide was reported as

detected. Appendix E of the “National Survey of Pesticides in Drinking Water Wells Phase I

Report” (EPA, 1990) was examined to determine which of the 13 pesticides were detected above

the MRL in the survey.
22

The second data source used for the occurrence screen is compliance monitoring data. EPA

received data from 11 States to assist in the chemical monitoring reform effort in early 1996. 

Monitoring data for both pesticides and IOCs were submitted as part of this effort. The States

that supplied occurrence data are: Alabama, Alaska, Arkansas, California, Georgia, Kansas,

Mississippi, Nebraska, New Jersey, Oregon, and Wisconsin. For the 14 pesticides, data was

submitted based on the analysis of 5,125 to 13,753 samples depending upon the contaminant. For

asbestos, data was submitted on the analysis of 1,225 samples. For antimony, data was submitted

on the analysis of 14,747 samples.

The screening criteria for contaminant occurrence and projected violations was as follows: 

no detections in the National Pesticide Survey, MCLs at least one order of magnitude higher than

the reporting limit for the compliance monitoring data, and a low positive rate in the compliance

data with no MCL exceedances. Five pesticides were removed from consideration based on those

criteria: carbofuran, 2,4-D, methoxychlor, dalapon, and picloram. Endothall was also removed

from consideration based solely on the relationship of the reporting limits for the State data and

the MCL and the very low positive rate (e.g., < 0.03%) in the compliance data. Carbofuran was

selected to illustrate this process for the five contaminants included in the National Pesticide

Survey because it had the lowest MCL/detection limit ratio. Detection limits for the regulated

SOCs are found in 40 CFR §141.24(h)(18). The listed detection limit for carbofuran is 0.9 Fg/L. 

The MCL for carbofuran is 40 Fg/L. The MCL is just over 44 times larger than the detection

limit. Carbofuran was detected in 23 out of 10,955 samples (0.23%) in the State compliance data. 

None of these samples exceeded the MCL. In addition, carbofuran was not detected in the

National Pesticide Survey, which had a MRL of 1.2 Fg/L for carbofuran. Based on the very small

percentage of detections and the large difference between the detection limit and the MCL, no

violations were projected for carbofuran. For endothall, only the compliance monitoring data was

used. The listed detection limit for endothall in 40 CFR §141.24(h)(18) is 9 Fg/L. The MCL for

endothall is 100 Fg/L. Endothall was only detected in 2 out of 6,218 samples, which converts to

0.03% of the samples. Neither of these samples exceeded the MCL. Based on this data, no MCL

violations were projected for endothall. The listed detection limits for the other four pesticides

removed by this screen can be found in 40 CFR §141.24(h)(18). A summary of the percentage of

positive samples in the compliance monitoring data and the National Pesticide Survey results can

be found in Table 1 at the end of this chapter. This table summarizes the screening process for all

of the 80 contaminants.

Section 2.3.3: Affordability Screens: No Violations

Only 10 contaminants remained after the projected violation screen was applied. EPA’s Safe

Drinking Water Information System (SDWIS) contains data on the compliance status of drinking

water systems. A query on violations for the 10 remaining contaminants was run on December

16, 1997 (EPA, 1997). This query looked for either of the following types of violation types: a

single sample violation of the MCL or an MCL violation based on the average of the most recent

four quarters of data. The other two violation types in SDWIS are monitoring and reporting

violations. Data on those violation types were not used for this screen, since MCL exceedances
23

cannot be predicted from that data. Since only systems with violations of the MCL will require

treatment, 5 contaminants were removed because there were no MCL violations. The violation

data on the 5 contaminants with MCL exceedances will be used in the affordable technology

determination described in Chapter 4. The contaminants that did not have any MCL exceedances

in SDWIS are all pesticides: alachlor, pentachlorophenol, dinoseb, diquat, and simazine.

For these 5 contaminants, the lack of violations was not the sole reason for removing them

from consideration for variance technologies. The compliance monitoring data from the 11 States

was also examined along with the SDWIS data. Alachlor and dinoseb had positive rates below

0.25% and no detections above the MCL. There were data submitted from 5,125 samples for

diquat. There were 60 positive samples (1.17%) between the detection limit of 0.4 Fg/L and the

MCL of 20 Fg/L. There was one positive sample (0.02%) reported that exceeded the MCL. 

Both pentachlorophenol and simazine had lower percentages of positive samples, but each had

very limited MCL exceedances. Table 1 at the end of this chapter provides more details on the

screens that were applied to each contaminant. Since the occurrence data was from 1996 and the

violation data in SDWIS was late 1997, it was assumed that the positives in the compliance data

were not MCL exceedances that would require treatment. However, violation data on all 5 of

these contaminants will be reviewed over the next year to see if new violations have been

recorded in SDWIS. If violations are found for these contaminants, that data would be used to

perform an affordable technology analysis, which is described in Chapter 4.

Section 2.4: Summary of Screening Process

Three contaminants were removed from consideration for variance technologies prior to the

screening process. The two-stage screening process evaluated the eligibility of the remaining 77

regulated contaminants for variance technologies. The results of the two-stage screening process

were that only five contaminants remained eligible for variance technologies. These five

contaminants were: antimony, asbestos, atrazine, di-(2-ethylhexyl) phthalate and lindane. These

contaminants proceeded through a more extensive affordability analysis where technology cost

estimates were compared with the national-level affordability criteria to determine if there is an

affordable compliance technology. This process is described in Chapter 4.

The entire screening process was presented at the May 18 and 19, 1998 stakeholder meeting. 

The two affordability screens that utilized occurrence data (lack of projected violations and lack

of violations) generated comments from stakeholders and States. Both were concerned that

systems with problems could be overlooked in the data sources used by EPA. EPA stated that the

lists are not static documents and that they can be updated if new data are received. For variance

technologies, this new data is not limited to technology performance. EPA noted that if data are

received showing violations for contaminants removed by the occurrence screens, then EPA

would use this data to determine if the system needed a variance technology. As was previously

noted, EPA believes that the results of this analysis would be subject to revision based on new

information and petitions from interested parties. 
24

TABLE 1

REGULATED CONTAMINANTS AND THEIR ELIGIBILITY FOR

VARIANCE TECHNOLOGIES AFTER TWO-STAGE SCREENING PROCESS

Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

Arsenic (pre-1986) NO Section 1415(e)(6)(A) of SDWA

(pre-1986 MCL not revised)2

50

Beta particle & photon 

radioactivity (pre-1986) NO

Section 1415(e)(6)(A) of SDWA

(pre-1986 MCL not revised)24 mrem 4 mrem

Gross alpha particle

activity (pre-1986) NO

Section 1415(e)(6)(A) of SDWA

(pre-1986 MCL not revised)215 pCi/L 15 pCi/L

Radium 226 & 228

(combined) (pre-1986)

NO Section 1415(e)(6)(A) of SDWA

(pre-1986 MCL not revised)25 pCi/L 20 pCi/L

Total Trihalomethanes NO MCL does not apply (applies only

to systems > 10,000 people)

100

Benzene NO Aeration is affordable 5 200

Carbon Tetrachloride NO Aeration is affordable 5 30

p-Dichlorobenzene NO Aeration is affordable 75 750

1,2-Dichloroethane NO Aeration is affordable 5 40

1,1-Dichloroethylene NO Aeration is affordable 7 70

1,1,1-Trichloroethane NO Aeration is affordable 200 1,000

Trichloroethylene NO Aeration is affordable 5 300
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

25

Vinyl Chloride NO URTH = MCL and Aeration is

affordable

2 2

Chlorobenzene NO Aeration is affordable 100 700

o-Dichlorobenzene NO Aeration is affordable 600 3,000

cis-1,2-Dichloroethylene NO Aeration is affordable 70 400

trans-1,2-Dichloroethylene NO Aeration is affordable 100 600

1,2-Dichloropropane NO Aeration is affordable 5 60

Ethylbenzene NO Aeration is affordable 700 1,000

Styrene NO URTH = MCL and Aeration is

affordable

100 100

Tetrachloroethylene NO Aeration is affordable 5 70

Toluene NO Aeration is affordable 1,000 2,000

Xylenes (total) NO Aeration is affordable 10,000 40,000

Dichloromethane NO Aeration is affordable 5 500

1,2,4-Trichlorobenzene NO Aeration is affordable 70 100

1,1,2-Trichloroethane NO Aeration is affordable 5 30

Giardia lamblia NO Section 1415(e)(6)(B) of SDWA NA

Legionella NO Section 1415(e)(6)(B) of SDWA NA
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

26

Standard Plate Count NO Section 1415(e)(6)(B) of SDWA NA

Turbidity NO Section 1415(e)(6)(B) of SDWA NA

Viruses NO Section 1415(e)(6)(B) of SDWA NA

Total Coliform NO Section 1415(e)(6)(B) of SDWA < 5% positives

Alachlor NO Detected in NPS above MRL of

0.5 Fg/L5, 0.13% positives: all

below MCL (State data)6, No

MCL exceedances in 12/97

SDWIS run10

2 40

Atrazine YES Detected in NPS above MRL of

0.12 Fg/L5, 1.34% positives: all

below MCL (State data)6, MCL

exceedances in 12/97 SDWIS

run10

3 30

Carbofuran NO Not detected in NPS with MRL

of 1.2 Fg/L5, 0.21% positives: all

below MCL (State data)6

40 50

Chlordane NO URTH . MCL (# 1 Fg/L

difference)

2 3

Dibromochloropropane NO Aeration is affordable 0.2 3
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

27

2,4-D NO Not detected in NPS with MRL

of 0.25 Fg/L5, 0.36% positives:

all below MCL (State data)6

70 100

Ethylene Dibromide NO URTH = MCL and aeration is

affordable

0.05 0.05

Heptachlor NO URTH . MCL (# 1 Fg/L

difference)

0.4 0.8

Heptachlor Epoxide NO URTH . MCL (# 1 Fg/L

difference)

0.2 0.4

Lindane YES Detected in NPS above MRL of

0.043 Fg/L5, 0.15% positives: all

below MCL (State data)6, MCL

exceedances in 12/97 SDWIS

run10

0.2 2

Methoxychlor NO Not detected in NPS with MRL

of 0.30 Fg/L5, 0.07% positives:

all below MCL (State data)6

40 50

Polychlorinated Biphenyls NO URTH = MCL 0.5 0.5

Pentachlorophenol NO Not detected in NPS with MRL

of 0.10 Fg/L5, 0.34% positives:

0.02% > MCL, 0.32% < MCL

(State data)6, No MCL

exceedances in 12/97 SDWIS

run10

1 30
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

28

Toxaphene NO URTH = MCL 3 3

2,4,5-TP NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2

50 70

Benzo(a)pyrene NO URTH = MCL 0.2 0.2

Dalapon NO Not detected in NPS5, 0.42%

positives: all below MCL (State

data)6

200 300

Di(2-ethylhexyl) adipate NO Aeration is affordable 400 3,000

Di(2-ethylhexyl) phthalate YES 3.72% positives: 0.98% > MCL,

2.74% < MCL (State data)6,

MCL exceedances in 12/97

SDWIS run10

6 300

Dinoseb NO Detected in NPS above MRL of

1.3 Fg/L5

, 0.26% positives: all

below MCL (State data)6, No

MCL exceedances in 12/97

SDWIS run10

7 10

Diquat NO 1.19% positives: 0.01% > MCL,

1.18% < MCL (State data)6, No

MCL exceedances in 12/97

SDWIS run10

20 80

Endothall NO 0.03% positives: all below MCL

(State data)6

100 200
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

29

Endrin NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2,

URTH . MCL (# 1 Fg/L)

2 3

Glyphosate NO Treatment option is affordable 700 1,000

Hexachlorobenzene NO URTH . MCL (# 1 Fg/L

difference)

1 2

Hexachlorocyclopentadiene NO Aeration is affordable 50 200

Oxamyl NO URTH = MCL 200 200

Picloram NO Not detected in NPS with MRL

of 0.5 Fg/L5, 0.13% positives: all

below MCL (State data)6

500 700

Simazine NO Detected in NPS with MRL of

0.38 Fg/L5, 0.64% positives:

0.01% > MCL, 0.65% < MCL

(State data)6, No MCL

exceedances in 12/97 SDWIS

run10

4 40

2,3,7,8-TCDD (Dioxin) NO URTH = MCL 3 x 10-5 3 x 10-5

Acrylamide NO Not a technology-based NPDWR9 TT 1

Epichlorohydrin NO Not a technology-based NPDWR9 TT 70

Fluoride NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2

4,000 5,000
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

30

Asbestos YES 5.71% positives: 0.41% > MCL,

5.30 % < MCL (State data)7,

MCL exceedances in 12/97

SDWIS run10

7 MFL 70 MFL

Barium NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2

2,000 5,000

Cadmium NO URTH = MCL 5 5

Chromium NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2

100 200

Mercury NO Section 1415(e)(6)(A) applies

because pre-1986 MCL retained2,

URTH = MCL

2 2

Nitrate (as N) NO Section 1415(e)(6)(A) applies

because pre-1986 MCL retained2,

URTH = MCL, acute effect

10,000 10,000

Nitrite (as N) NO URTH = MCL, acute effect 1,000 1,000

Total Nitrate & Nitrite (as N) NO URTH = MCL, acute effect 10,000 10,000

Selenium NO Section 1415(e)(6)(A) applies

because pre-1986 MCL raised2

50 200
Contaminant1 Are Variance

Technologies an Option?

Rationale MCL

(Fg/L)

URTH Value3

(Fg/L)

31

Antimony YES 2.08% positives: 0.24% > MCL,

1.84% < MCL (State data)8,

MCL exceedances in 12/97

SDWIS run10

6 10

Beryllium NO URTH = MCL 4 4

4

Cyanide (as free cyanide) NO URTH = MCL and treatment

option is affordable

200 200

Thallium NO URTH . MCL (# 1 Fg/L

difference)

2 2.3

Lead NO Corrosion Treatment is affordable 15 (TT) 30

Copper NO URTH = Action level, acute

effect, Treatment is affordable

1,300 (TT) 1,300

NOTES:

 1) Aldicarb, aldicarb sulfoxide, aldicarb sulfone, and nickel are not included since the MCLs for these contaminants are not in

effect.

 2) Section 1415(e)(6)(A) states that a small system variance shall not be available for any maximum contaminant level or

treatment technique for a contaminant with respect to which a national primary drinking water regulation was promulgated

prior to January 1, 1986. See text for details on the interpretation of this requirement.

 3) These URTH values have been estimated using the procedures in “Toxicological Basis for Drinking Water: Unreasonable Risk
32

to Health Values” (Orme-Zavaleta, 1992) and the health advisory data in “Drinking Water Regulations and Health Advisories”

(EPA, 1996). The calculation of URTH values is currently under review at EPA. EPA will issue a revised guidance manual

for determining URTH as a result of that process. The URTH values listed in this table will be modified or recalculated based

on revisions to the procedures for determining URTH values. The values in this table should be considered an interim

estimate for URTH and will be replaced by the values in the forthcoming URTH guidance. This guidance manual will be

updated to incorporate the revised URTH values.

 4) The URTH for beryllium was estimated at the MCL because the 10-4 cancer risk level is lower than the MCL, even though the

MCLG was set based on Category II process. The derivation of the MCLG included a safety factor of 10 to account for

possible carcinogenic effects of beryllium via ingestion since the data did not support classifying beryllium as a carcinogen

through ingestion. However, the URTH guidance states that the safety factor can be removed as long as the 10-4 risk level is

not exceeded.

 5) These analytes were included in the National Pesticide Survey [National Survey of Pesticides in Drinking Water Wells] that

was conducted by EPA and examined both Community Water System wells and rural domestic wells. The MRL is the

minimum reporting limit used for the analytes in the NPS. All positive samples would have concentrations at or above the

MRL.

 6) Compliance monitoring data from 11 States were submitted to assist EPA in the development of Chemical Monitoring

Reform. For these pesticides, the total number of sites monitored ranged from 5,125 to 13,753 depending upon the

contaminant. The States that submitted data are: Alabama, Alaska, Arkansas, California, Georgia, Kansas, Mississippi,

Nebraska, New Jersey, Oregon, and Wisconsin.

 7) Compliance monitoring data from the same 11 States were also submitted on asbestos. The percentages are based on data

from 1,225 sites.

 8) Compliance monitoring data from the same 11 States were also submitted on antimony. The percentages are based on data

from 14,747 sites.

 9) The NPDWRs for acrylamide and epichlorohydrin are treatment techniques that require a certification that when they are used

in drinking water, the product of dose and monomer does not exceed certain levels. Since this is not a technology-based
33

standard, there are no compliance or variance technologies.

 10) A 12/16/97 run of SDWIS (EPA, 1997) was done for ten contaminants to determine if there were MCL exceedances. 
34

REFERENCES

Orme-Zavaleta, Jennifer. 1992. Toxicological Basis for Drinking Water: Unreasonable Risk to

Health Values. Journal of the American College of Toxicology. 11(3): 325 - 329.

National Research Council (NRC). 1997. Safe Water from Every Tap: Improving Water Service

to Small Communities. Washington, D.C.: National Academy Press.

USEPA. 1990. National Survey of Pesticides in Drinking Water Wells Phase I Report. EPA

570/9-90-015. Washington, D.C.: EPA Office of Water and Office of Pesticides and Toxic

Substances.

USEPA. 1996. Drinking Water Regulations and Health Advisories. EPA 822-B-96-002. 

Washington, D.C.: EPA Office of Water.

USEPA. 1997. Unpublished data from the Safe Drinking Water Information System. 

Washington, D.C.: EPA. December 16, 1997.

USEPA. 1998a. Federal Register 63(75): 19442. April 20, 1998.

USEPA. 1998b. Federal Register 63(157): 43834. August 14, 1998.

USEPA. 1998c. National-Level Affordability Criteria Under the 1996 Amendments to the Safe

Drinking Water Act. Prepared by International Consultants, Inc., Hagler Bailly Services, Inc. and

Janice A. Beecher, Ph.D. for the EPA. August 1998.

USEPA, 1998d. Small System Compliance Technology List for the Non-Microbial Contaminants

Regulated before 1996. EPA 815-R-98-002. Washington, D.C.: EPA Office of Water. 

September 1998.
35

3.0 NATIONAL-LEVEL AFFORDABILITY

Section 3.1: Introduction

Section 1412(b)(15)(C) of the SDWA requires EPA to list any assumptions used in

determining affordability, taking into consideration the number of persons served by such systems

when variance technologies are listed. Even though EPA did not list variance technologies in the

August 6, 1998 Federal Register notice (EPA, 1998a), the affordability criteria used by EPA for

these findings were included in the notice. These affordability criteria were used to identify

affordable compliance technologies for some of the regulated contaminants. EPA compared

technology cost estimates for each small size category against an affordable technology criterion

for those regulations where a small system variance could be granted. The affordable compliance

technologies are discussed in “Small System Compliance Technology List for the Non-Microbial

Contaminants” (EPA, 1998b).

The size category-dependent affordable technology criteria are collectively referred to as

“national-level affordability criteria.” This nomenclature has been used to distinguish the nationallevel affordability criteria from the “system-level affordability criteria” that States will use for

determinations affecting individual systems. EPA published information regarding these systemlevel affordability criteria in February, 1998 (EPA, 1998c). This information was required by

Section 1415(e)(7)(B) of the SDWA. There are three provisions of the SDWA that refer to these

system-level affordability criteria. Section 1415(e) provides for affordability-based variances,

under certain circumstances, for small drinking water systems. Section 1416 allows for

exemptions that provide systems facing compelling economic factors additional time to comply

with SDWA requirements. Small systems could receive as long as nine additional years to

comply. Finally, Section 1452(b) provides that affordability on a per household basis shall be one

of the three factors used to prioritize systems for assistance from the new Drinking Water State

Revolving Fund (DWSRF). The system-level affordability criteria can be different for different

purposes. For example, States can use different affordability criteria to make decisions about

whether a system should receive a small system variance and when a system should receive

additional subsidization from the DWSRF. In fact, the threshold used for additional assistance for

systems meeting a NPDWR would likely be lower than the threshold used to determine when a

system would operate at a level that does not provide an equivalent level of protection as meeting

the MCL.

The national-level affordability criteria for the affordable variance technology determinations

will also be different from the system-level criteria used by the State to determine if a system

should receive a small system variance. Technologies determined to be “unaffordable” under the

national-level affordability criteria may still be affordable for a specific system within the size

category, in which case the system may install that technology if it so chooses. Conversely, if a

financially disadvantaged small water system out of compliance with a NPDWR cannot afford any

of the compliance technologies that are determined to be “affordable,” one option for that system

would be to apply to the State for an exemption. This process is available for regulations
36

promulgated after 1996. Such a system cannot apply for a new exemption for the regulations

issued prior to August 6, 1998. Those small systems with existing exemptions for rules in effect

on August 6, 1998 may continue to get renewals of their exemptions until the exemption period

has run out. That means that a small system can have no more than 9 years after the Section 1412

compliance date to meet the applicable MCL/treatment technique even if the exemption was

issued prior to the 1996 SDWA Amendments.

Section 3.2: Role of National-Level Affordability Criteria

The role of the national-level affordability criteria was discussed briefly in Section 1.3 of this

document. Figure 2 in that section showed the role that national-level affordability criteria play in

the treatment technology arena. The primary function of the criteria is to determine whether a

system of a given size/source water quality combination should proceed down the compliance or

variance technology pathway. The secondary function is to define the universe of technologies

within the compliance or variance technology pathway. Since affordable compliance technologies

were identified for all of the regulated contaminants, the variance technology pathway will not be

utilized at this time. The secondary function of the national-level affordability criteria is

demonstrated in the compliance technology tables (EPA, 1998b). For the smallest size category,

technologies that met the national-level affordability criteria and those that did not meet the

national-level affordability criteria were identified.

The primary function of the national-level affordability criteria is to determine whether the

treatment goal of the water system should be compliance with the NPDWR or whether the system

should proceed down the variance pathway towards obtaining a small system variance. A

variance technology must be installed to obtain a small system variance. The variance technology

may not achieve compliance with the NPDWR, but will achieve the maximum reduction or

inactivation that is affordable considering the size of the system and the quality of the source

water. Thus, the treatment objective for a variance technology might be a concentration that is

higher than the MCL. This higher concentration must be protective of public health, considering

the quality of the source water and the expected useful life of the technology. Variance

technologies cannot be identified if they are not protective of public health [see Section

1412(b)(15)(B) of the SDWA]. The treatment goal under a small system variance is to be within

the range identified as being protective of public health. This range would start at the MCL and

would go up to the maximum concentration that is still protective of public health based on the

expected useful life of the technology. The actual treatment goal is to be as close to the MCL as

is affordable within the protective of public health range.

The national-level affordability criteria help define the range of options available to a small

system that is out of compliance with a NPDWR. The overall range of options are: 1) install a

technology to comply with the NPDWR; 2) receive an exemption and then install a technology to

comply with the NPDWR; or 3) obtain a small system variance (if option is available). For the

two compliance options, the system is not required to install a compliance technology identified

by EPA. The compliance technology list is intended as guidance to provide small systems with
37

information concerning the types of technologies that can be used to comply with the NPDWR. 

Systems can install other technologies that are not on the list to comply with the NPDWR. 

Alternate source and regionalization options are also available for a system to comply with a

NPDWR. The compliance option can be characterized as a “pay now” approach. The exemption

followed by compliance option can be characterized as a “pay later” approach. The small system

variance option can be characterized as “pay less for less” approach. These systems will not have

the same level of protection as systems complying with the NPDWR during the duration of the

small system variance. Households in these systems will likely have lower water bills than they

would if the system were in full compliance with the NPDWR. There are NO no-cost options

available for violations of NPDWRs. All three options have treatment costs associated with them. 

When a variance technology is installed, there are additional administrative costs associated with

the small system variance procedures. These procedures are detailed in the final Variance and

Exemption Rule (EPA, 1998d). The national-level affordability criteria will determine when the

“pay less for less” option will be available. 

Section 3.3: Unit of Measure for the National-Level Affordability Criteria

Public water systems fall into one of three categories. A community water system (CWS) is

a public water system which serves at least 15 service connections used by year-round residents or

regularly serves at least 25 year-round residents. A non-transient non-community water system

(NTNCWS) is a public water system that is not a community water system and that regularly

serves at least 25 of the same persons over 6 months per year. A transient non-community water

system (TNCWS) is a non-community water system that does not regularly serve at least 25 of

the same persons over six months per year.

Community water systems can absorb water service cost increases by directly charging their

customers in the form of increased water bills. Community water systems serve both residential

and non-residential customers. The majority of the customers in small systems are residential or

household connections. System size and the percentage of non-residential customers are directly

related. Thus, the typical system in the smallest size category relies almost exclusively on

residential customers. Since there are so few non-residential customers, the ability of these

systems to spread the cost of SDWA compliance beyond the household level is restricted. The

other two size categories have a larger percentage of non-residential customers, but residential

customers still account for the majority of the revenues received by the water system. The

national-level affordability criteria for CWSs are based on the ability of household customers to

shoulder the additional costs of installing a technology to meet a NPDWR. For more information

on the selection of the household as the most sensitive user for cost increases, see “National-Level

Affordability Criteria Under the 1996 Amendments to the Safe Drinking water Act” (EPA,

1998e).

For non-community water systems, the operation of the system is generally peripheral to

some other type of business or activity. These systems are generally engaged in an enterprise

other than water supply and do not rely directly on households to recover water production costs. 
38

A second document evaluated non-community water systems (NCWS) and compared their

vulnerability to cost increases with households in community water systems [see background

document entitled “An Assessment of the Vulnerability of Non-community Water Systems to

SDWA Cost Increases” (EPA, 1998f)]. The conclusion was that the categories of NCWSs were

either not vulnerable to SDWA-related treatment cost increases or were less vulnerable to

SDWA-related treatment cost increases than a typical household.

One other element in the 1996 Amendments to the SDWA provides a very cost-effective

solution for NTNCWSs. Since variance technologies are only an option for chronic contaminants,

point-of-use devices are an available compliance technology option. Most NTNCWSs only

provide a very small portion of the water for drinking purposes. Point-of-use devices could be

installed on all taps where water is used for human consumption or food preparation. Treatment

costs would be much higher if all the water provided by the system was treated to meet drinking

water standards. 

TNCWSs are only required to treat for acute contaminants. These include microbial

contaminants and nitrate. As discussed in Chapter 2, there are statutory prohibitions against

variance technologies for these contaminants. Therefore, variance technologies are not an option

and national-level affordability criteria are not needed for this category of public water systems.

Since the household was determined to be more vulnerable to treatment cost increases than

the various categories of non-community water systems, national-level affordability based on

households would serve as an adequate surrogate for NTNCWSs as well as CWSs. Therefore,

whether treatment is affordable depends upon how treatment costs compare with existing

household water costs. The selected approach was to equate user burden to the increase in

annual household water bills that would result from installation of treatment. To determine if

there are any affordable compliance technologies for a given NPDWR, the national-level

affordability criteria are compared against the cost projections for the applicable treatment

technologies. If there are no affordable compliance technologies, then variance technologies

would become an option. 

Section 3.4: Derivation of the National-Level Affordability Criteria

A summary of the methodology used to determine the national-level affordability criteria is

described below. The household is the focus of the national-level affordability analysis. 

Treatment technology costs are presumed affordable to the typical household if they can be shown

to be within an affordability index range (defined as a range of percentages of median household

income) that appears reasonable when compared to other household expenditures. This approach

is based on the assumption that affordability to the median household served by the CWS can

serve as an adequate proxy for the affordability of technologies to the system itself. EPA has

chosen to express the water system financial and operational characteristics using their median

values, which is a measure of their respective central tendencies. EPA believes that the nationallevel affordability criteria should describe the characteristics of typical systems and should not
39

address extreme situations where costs might be extremely low or excessively burdensome.

The national-level affordability criteria have two major components: current annual water

bills (baseline) and the affordability threshold (upper limit for water bills). The current annual

household water bills were subtracted from the affordability threshold to determine the maximum

increase that can be imposed by treatment and still be considered affordable. This difference was

compared with the converted treatment costs to make the affordable technology determinations. 

This difference is called the available expenditure margin.

The affordability threshold was determined by comparing the cost of public water supply for

households with other household expenditures and risk-averting behavior (such as use of bottled

water or point-of-use devices). National expenditure estimates were derived to illustrate the

current allocation of household income across a range of general household expenditures. This

consumer expenditure data provided a basis for determining the affordability threshold by

comparing baseline household water costs to median household income (MHI) to determine the

financial impact of increased water costs on households.

Section 3.4.1: Derivation of Baselines 

 Baselines were determined for the three parameters needed to perform the affordable

technology analysis. These parameters are: annual household consumption, current annual water

bills, and median household income. Separate baselines for the three parameters were established

for each of the three system size categories. Annual household consumption was used to convert

treatment cost increases into household impacts as discussed in Section 4.4 of this document. 

Current annual water bills were subtracted from the affordability threshold to determine the

available expenditure margin. The median household income was used to translate the threshold

percentage into an actual dollar figure.

The baselines for annual household water consumption and the current annual water bills

were derived from data in the 1995 Community Water System (CWS) Survey. EPA began the

1995 CWS Survey in the fall of 1994. In June 1995, the surveys were distributed to a stratified

random sample of 3,700 water systems nationwide. Community water system respondents had

until February 1996 to return the completed questionnaires. Slightly more than 54 percent of the

systems that received questionnaires responded to the survey. For more information on the 1995

CWS Survey and an overview of the results, see “Community Water System Survey Volume I: 

Overview” (EPA, 1997a). For detailed survey result tables and copies of the survey

questionnaires, see “Community Water System Survey Volume II: Detailed Survey Result Tables

and Methodology Report” (EPA, 1997b).

EPA’s goal was to define a typical system within each small system category for affordability

purposes. This is very similar to the model systems approach that is used to evaluate the cost of

treatment. Under that approach, a typical system is created with the following parameters: design

flow, average daily flow, and population served within the size category. Water systems that
40

purchase 90% or more of their water were excluded from the baseline determinations. These

systems were assumed to obtain high quality finished water from larger systems that can achieve

economies of scale necessary to mitigate the increased cost of SDWA treatment requirements. 

Data from water systems with zero values for critical variables were also excluded from the

baseline determinations. The data for current household water bills was one such critical variable. 

The remaining observations were graphed as a scatter plot to examine the dispersion of data

points. After evaluating this data, all data outside of three standard deviations (+/-) of the mean

value were excluded from the analysis. 

Two data sources were required to derive the median household income (MHI) for small

systems. The median household income data were derived by linking the CWSS data with data in

the 1990 Census using zip codes. The CWS Survey provided information on zip codes served by

individual water systems. The Census income data were converted from 1990 dollars to 1995

dollars using the consumer price index to facilitate comparison with the CWS Survey data. Some

data had to be excluded from this analysis because it did not represent a typical small system. Zip

codes were reported using either the three-digit zip codes or five-digit zip codes depending upon

the water system’s service area. The use of the three-digit zip code placed several large

metropolitan areas in the overall sample. Because the three-digit zip codes observed in the CWS

Survey data consistently represent large metropolitan area, these values were removed from the

analysis of small system income. 

The “National-Level Affordability Under the 1996 Amendments to the SDWA” (EPA,

1998e) presents data for the annual water consumption, current water bills and median household

income. Both means and medians were determined for each parameter for each size category. 

Mean values can be considered better estimates of items in their given distributions and are better

suited to further mathematical manipulation. However, median values, are considered a better

estimate of typical systems because the median represents the middle value and are not affected by

extremely high or low values. Stakeholders were asked whether mean or median values for the

three parameters should be used to establish the national-level affordability criteria. Stakeholders

recommended consistency rather than a preference for using means or medians. EPA selected

median values for all three parameters. EPA has chosen to express the water system financial and

operational characteristics using their median values, which is a measure of their respective central

tendencies. EPA believes that the national-level affordability criteria should describe the

characteristics of typical systems and should not address extreme situations where costs might be

extremely low or excessively burdensome. The mean values were higher than the median values

for all of the parameters and size categories. For a given affordability threshold, the available

expenditure margin was lower when median values were used.

The annual water consumption rates derived from the CWS Survey data are contained in

Table 2. Only the median values for water consumption are included for each size category. The

data are reported in 1,000 gallons per connection (kgal/connection). These consumption rates are

considerably lower than the 100,000 gallons per household per year that was used in the

development of the regulations before 1996. This consumption rate was based on large systems
41

and was extrapolated to all system size categories. The use of the annual consumption rate in

making affordable technology determinations is discussed in detail in Chapter 4.

Table 2

Residential Consumption at Small Water Systems

System Size Category 

(Population Served)

Median Annual Consumption

(kgal/connection)

25 - 500 72

501 - 3,300 74

3,301 - 10,000 77

The current annual water bills were also derived from the CWS Survey data. The CWS

Survey did not directly ask for data on annual water bills. The CWS Survey did ask for data on

annual sales revenue per connection by customer type. The data on residential connections were

used to represent the total amounts that customers were billed during the year.

EPA evaluated the effect of source type on current annual water bills during the development

of the national-level affordability criteria. Since the surface water treatment rule was promulgated

in 1989, in-place treatment might be much more extensive in surface water systems than ground

water systems. Since existing treatment would likely lead to higher costs, EPA looked at current

water bills in both types of systems. For this analysis, the ground water systems were those

systems that relied exclusively on ground water. All mixed systems were placed in the surface

water system category. Ground water systems significantly outnumbered the surface water

systems in all three size categories, even with the inclusion of mixed systems in the surface water

category. This relationship is consistent with the profile of CWS in that ground water dominates

as the source in smaller systems and surface water dominates as the source in larger systems. 

Table 3 contains the current annual water bills by source type for each size category. Table 4

contains the current annual water bills for all systems for each size category.
42

Table 3

Baseline Household Water Bills by Source Type

System Size Category

(Population Served)

Current Annual Water Bills

($/household/yr)

Surface Water Systems Ground Water Systems

25 - 500 $179 $211

501 - 3,300 $228 $183

3,301 - 10,000 $225 $173

Stakeholders were asked if separate baselines should be established for ground water systems

and surface water systems. Stakeholders stated that separate baselines should be established, but

that the distinction between ground water and surface water systems was less significant in small

systems because most rely on ground water. EPA evaluated the data in Table 3 and determined

that there was very little distinction between current annual water bills for ground water systems

as compared to surface water systems. Thus, separate baselines were not established and the data

in Table 4 were used for each size category. If separate baselines are established in the future, an

in-place treatment baseline would also need to be established for surface water systems since most

filtration technologies can be modified to remove other contaminants. Thus, future treatment

decisions would likely involve modification of the existing process rather than installation of a

new process. The technology cost evaluation is discussed in more detail in Chapter 4.

Table 4

Baseline Household Water Bills

System Size Category

(Population Served)

Median Current Annual Water Bills

($/household/yr)

25 - 500 $211

501 - 3,300 $184

3,301 - 10,000 $181

The baseline annual household water bills include existing water quality, water production,

and water distribution costs. Water production costs include labor and energy for pump

operation to supply water to customers. Water distribution costs include costs of infrastructure

repair (mains and service lines) and administrative costs (customer billing and meter checking). 

The existing water quality costs include both treatment and monitoring. The CWS Survey data
43

were collected in 1995, so treatment costs for many of the regulated contaminants may already be

accounted for in the baseline. For the majority of the small systems, the bulk of the current

`annual household water bills are related to water production and distribution. Most ground

water systems do not have extensive treatment trains. 

The median household income data were derived from the 1995 CWS Survey and the 1990

Census. The linking procedure was discussed earlier. A MHI value was derived for each zip

code served by the system. An average MHI was then determined for those systems that reported

serving multiple zip codes. Means and medians were determined after the MHIs for each system

were then grouped by size category. The median of the system-MHI values is presented for each

size category in Table 5.

Table 5

Baseline Median Household Income

System Size Category

(Population Served)

Median System-MHI

(Census MHI - updated to 1995$)

25 - 500 $30,785

501 - 3,300 $27,058

3,301 - 10,000 $27,641

It should be noted that the data in Table 15 - National-Level Affordability Criteria - published

in the Announcement of Small System Compliance Technology Lists for Existing National

Primary Drinking Water Regulations and Findings Concerning Variance Technologies 63 Fed.

Reg. p. 42046 (August 6, 1998) presented mean values for current water bills instead of median

values. Use of mean values in Table 15 was in error. As stated in the Federal Register notice,

EPA’s intent was to use the median values, and this intent has not changed. The data in Table 4

are the median values for current annual water bills. The median household income for the two

smallest size categories in Table 5 is slightly higher than the values in Table 15 of the Federal

Register notice. A verification run of the MHI data produced slightly higher MHIs for these two

size categories. The calculations using the data in Tables 4 and 5 of this document do not alter

the affordability determinations discussed in the Federal Register notice in any way.

Section 3.4.2: Derivation of the Affordability Threshold

The affordability threshold was determined by comparing the cost of public water supply for

households with other household expenditures and risk-averting behavior. National expenditure

estimates were derived to illustrate the current allocation of household income across a range of

general household expenditures. This consumer expenditure data provided a basis for determining

the affordability threshold by comparing baseline household water costs to median household
44

income (MHI) to determine the financial impact of increased water costs on households.

Chapter 3 in “National-Level Affordability Criteria Under the 1996 Amendments to the

SDWA” (EPA, 1998e) describes how comparative household expenditures were used to identify

a range of options for the affordability threshold. The options range from 1.5% to 3.0% MHI. 

This approach is summarized below.

Data from the Consumer Expenditure Survey (CES) conducted by the Bureau of Labor

Statistics (BLS) were used as the source for many of the household expenditures. The BLS

defines an individual household as any of the following: 1) all members of a particular household

related by blood, marriage, adoption, or other legal arrangements; 2) a financially independent

person living alone or sharing a household with others, including a private home, lodging house,

or permanent living quarters in a hotel or motel; or 3) two or more individuals living in the same

residence, utilizing their combined income for joint expenditure decisions. For the second

criterion, financial independence is defined as sole responsibility for any two of the following three

expenses: housing, food, and other living expenses. 

Direct comparisons between the CES data and the data derived from the CWS Survey are

not possible for several reasons. The BLS’s survey methodology is not designed to establish an

exclusive cost for drinking water. CES data are based on reported household expenditures for

water and other public services. This category includes wastewater and solid waste collection

expenditures. In addition, the CES data values represent the average for all consumer units within

specific demographic strata, such as size of consumer unit, income level, and region. Some

expenditures may appear lower than anticipated because the value for this expenditure category is

averaged over all consumer units regardless of whether they purchased the item. Another factor

that may make the water expenditures appear lower is that data from households in large systems

are included in the CES data. These households may experience lower water bills due to the

greater economy-of-scale in large systems. The impact of these two factors is illustrated by

comparing the CES data for water and other public services with the current water bill baseline

for households in small systems. The CES data indicate that households are paying about 0.7% of

their before tax income on water and other public services. Using the data in Tables 4 and 5,

current water bills range from 0.65% to 0.69% of the median household income in the three small

system size categories. Wastewater and solid waste collection will be higher than 0.05%, so

direct comparison of the two data sources is not possible. However, the CES data can be used as

a relative benchmark to compare the cost of water with other expenditures.

 

The complete range of household expenditures is described in the National-Level

Affordability Document. A subset of the complete list was selected for use as comparable

expenditures. In the CES data, there is a category for utilities, fuels, and other public services. 

Water and other public services is included in this category. Expenditures for natural gas,

electricity, and fuel oils and other fuels are also included in this category. These three utilities are

competitors for power and heating, so households that do not purchase one or more of these

utilities would bias the individual percentages. These three utilities were combined into one
45

category called energy and fuels in the analysis in the National-Level Affordability Document

(EPA, 1998e). The subset of comparable expenditures from the CES data is contained in Table 6.

Table 6

Summary of Select Consumer Expenditures for All Consumer Units - 1995$

Item Consumer Expenditure as % of Income before

taxes

Housing 28.3%

Transportation 16.3%

Food 12.2%

Energy and Fuels 3.3%

Telephone 1.9%

Water and other Public Services 0.7%

Entertainment 4.4%

Alcohol and Tobacco 1.5%

EPA identified an initial range of options using the CES data for the national-level

affordability criteria. A floor of 1.5% of income was based on the expenditures for alcohol and

tobacco in the CES data. The upper limit of 3% was based on rounding down the energy and

fuels percentage listed in Table 6. Stakeholders were presented with an initial range for the

affordability threshold of 1.5% to 3% of the MHI for each size category. Stakeholders, in

general, did not express a strong opinion about where the affordability threshold should be set

within the range. EPA selected 2.5% based on the rationale described below.

The National-Level Affordability Document contained several other comparable expenditures

that were used to identify a specific affordability threshold within the range of 1.5% to 3%. The

telephone expenditures in Table 6 would support an affordability threshold of 2%. The other two

expenditures looked at risk-reduction activities for drinking water. Installation of a point-of-use

device or the use of bottled water as an alternative to the water supplied by the system was

examined.

Section 1412(b)(4)(E)(ii) of the SDWA identifies both Point-of-Entry (POE) and Point-ofUse (POU) treatment units as options for compliance technologies. A POE treatment device is a

treatment device applied to the drinking water entering a house or building for the purpose of

reducing contaminants in the drinking water distributed throughout the house or building. A POU

treatment device is a treatment device applied to a single tap used for the purpose of reducing
46

contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen

tap. 

The SDWA also identifies requirements that must be met when POU or POE units are used

by a water system to comply with a NPDWR. Section 1412(b)(4)(E)(ii) stipulates that “point-ofentry and point-of-use treatment units shall be owned, controlled, and maintained by the public

water system or by a person under contract with the public water system to ensure proper

operation and maintenance and compliance with the MCL or treatment technique and equipped

with mechanical warnings to ensure that customers are automatically notified of operational

problems.” Other conditions in this section of the SDWA include: “If the American National

Standards Institute has issued product standards applicable to a specific type of POE or POU

treatment unit, individual units of that type shall not be accepted for compliance with a MCL or

treatment technique unless they are independently certified in accordance with such standards.” 

A supporting document entitled “Cost Evaluation of Small System Compliance Options: 

Point-of-Use and Point-of-Entry Treatment Units” (EPA, 1998g) summarizes EPA’s approach to

meeting the SDWA requirements on these devices as compliance technologies. Since programs

for long-term operation, maintenance, and monitoring must be provided by water utilities, this

option is probably limited to the first size category (25 - 500 people). A system serving 500

people probably has between 150 and 200 households. The system would be responsible for

operation, maintenance, and monitoring of a unit at or in each of these households. This is

probably the realistic upper bound for the effective management of either of these options. The

median number of connections for systems in the 25 - 500 size category is 50. The data in Tables

4.4.3 of the POU/POE report were used to evaluate the cost of centrally-managed POU and POE

options. Household cost increases for this option were developed for several technologies: 

reverse osmosis, anion exchange, activated alumina, and granular activated carbon. The

affordability threshold would need to be at or above 2% for the POU treatment units option to be

affordable. The affordability threshold would need to be above 2.5% for the POE treatment unit

option to be affordable once waste disposal costs were included. EPA does not believe that the

affordability threshold should be set so low that two options specifically identified in the SDWA

as compliance technologies would never qualify as compliance technologies. As it is, POE

devices would not be listed as an affordable compliance technology using the selected affordability

threshold. The POU costs support an affordability threshold between 2 and 2.5%. The POE

costs support an affordability threshold of 2.5% or greater.

The cost of bottled water as an alternate source of water that meets the NPDWRs was also

investigated as a risk-reduction activity. For this analysis, a household of three people was

assumed. Water consumption was estimated at 2 liters per person per day. This same assumption

is used to derive the drinking water equivalent level (DWEL) that was discussed briefly in Section

2.2.3. The DWEL is used to determine the MCLG for the regulated non-carcinogenic

contaminants. A cost per gallon rate of $0.98 was used for this analysis. This rate is the average

price for home delivery from the International Bottled Water Association. A cost per household

per year of approximately $570 was derived from these data. The bottled water costs would be in
47

addition to what the household is currently paying for water. The bottled water costs support an

affordability threshold of 2.5% or higher, depending upon the size category.

Another factor in the decision of where to set the affordability threshold was that EPA

believes that small system variances are intended to be very rare, based on the requirements of the

SDWA. Variance technologies are intended for systems with very poor source water such that

the costs of compliance would not be affordable. Thus, the affordability criteria should be set, in

EPA’s view, high enough that the majority of the systems will proceed down the compliance

pathway. The compliance and variance pathways are illustrated in Figure 2 in Section 1.3. The

right-hand side of this figure shows the steps that a small system must pass through before

receiving a small system variance and installing a variance technology. 

The first step is to determine if there is an affordable compliance technology. Variance

technologies are only identified when there are no affordable compliance technologies. As long as

one potential compliance technology can pass the affordability criteria, there won’t be variance

technologies. If there are five potential compliance technologies and only one passes the

affordability criteria, variance technologies would not be identified for that system size/source

water quality combination. This shows that the goal for most systems should be compliance with

the NPDWR, since only one technology needs to meet the affordability criteria to eliminate the

availability of variance technologies. When affordable compliance technologies are not available,

variance technologies will be identified. However, small systems must evaluate the affordability

of treatment, alternate source, and restructuring at the system-level before a small system variance

can be considered. Thus, the structure of the SDWA requirements indicates that small system

variances should be considered as a last resort.

The approach to establishing the national-level affordability criteria did not establish a

baseline for in-place treatment technology. The baseline for annual water bills was determined for

each size category rather than creating many smaller sub-categories based on the degree of

existing treatment. There were two reasons for this approach. The difference between annual

water bills in ground water and surface water systems was not significant even though there

would be differences in existing treatment. The second reason is that the sample size of the data

that would be used to determine the baseline for annual water bills would be very small for some

of the sub-categories. One consequence of this approach is that some of the treatment costs for

the regulations covered in this guidance are already included in the baseline of annual water bills. 

The regulations for the contaminants that were initially eligible to receive small system variances

were promulgated between 1986 and 1992. The CWS Survey was conducted in 1995. Some of

the treatment costs are already incorporated into the baseline for current annual water bills. A

group of five small surface water systems with annual water bills above $500 per household per

year were examined. All of these systems had installed disinfection and filtration technologies to

comply with the surface water treatment rule (SWTR). The SWTR was promulgated in 1989. 

The treatment cost comparisons in Chapter 4 assumed that there was no existing treatment

capable of removing the contaminant or being modified to remove the contaminant. This is a

conservative assumption for some systems (especially surface water systems) because they have
48

already made an investment in technology that is reflected in the customer’s annual water bills. 

The assumption that these systems would need to install a new technology overestimates the costs

of compliance for these systems.

Another important factor is that under this approach to national-level affordability criteria,

the affordability threshold is set at 2.5% of MHI for existing and future regulations. The baseline

for annual water bills will increase as treatment is installed to comply with regulations and as

backlog infrastructure needs are met. EPA intends to conduct the Community Water Supply

Surveys every five years and will be able to track the increases in water bills due to treatment or

infrastructure repair. In the interim, between CWS Surveys, EPA will adjust the baseline for

annual water bills to incorporate the projected impact of regulations. For example, if arsenic

follows the disinfection by-product, and radon rules, the impact of these rules will be incorporated

into the baseline annual water bills used to make the affordable technology determinations for

arsenic. Since the baseline water bills will be higher, the available expenditure margins for

comparison with arsenic treatment costs will be lower than that listed in Section 3.5. The

consumer price index data shows water prices increasing at a faster rate than all items over the

last 10 years (EPA, 1998e). This implies that water prices should increase faster than median

household income and that the available expenditure margin will decrease over time. The impacts

of new regulations will further decrease the available expenditure margin over time. Thus, while

variance technologies are not available for the currently regulated contaminants, a decreasing

available expenditure margin increases the likelihood of variance technologies for future

regulations.

The final piece of supporting rationale is that EPA believes that the goal of the SDWA is still

to provide the same high quality drinking water for all customers of public water systems. The

SDWA does not, in EPA’s view, envision a two-tiered approach for standards where large

systems are complying with the NPDWR and small systems are operating at some level above the

MCL that is protective of public health for the duration of a small system variance. The small

system variance option should be the exception and not the rule. Ideally, only a small subset of

small systems would ever operate under a small system variance. If the affordability threshold

were set so low that variance technologies were needed for regulations that were promulgated at

least six years ago, then affordability would be a significant issue for all future regulations. Under

such an affordability threshold, the small system variance option would become the rule rather

than the exception. 

Section 3.5: National-Level Affordability Criteria

The national-level affordability criteria are based on an affordability threshold of 2.5% of the

median household income (MHI). As discussed in Section 3.4.1, the baseline values for median

household income and current water bills have changed slightly from the Federal Register notice. 

The correct baseline water bills ranged from 0.65% to 0.69% MHI in the three size categories. 

Thus, the available expenditure margins were approximately 1.8% MHI for each size category. 

Table 7 summarizes the national-level affordability criteria and shows the maximum increase that
49

could occur using these criteria. 

Most systems would not be expected to actually experience cost increases of this magnitude

if a compliance technology was installed. Many compliance technologies impose substantially

lower household costs. For example, the screening process examined several technologies that

imposed less than $300/household per year increases in all three size categories. The treatment

costs used for the affordable technology determinations were based on treatment of all of the

water to achieve the maximum removal efficiency. Most systems will not need the maximum

removal efficiency to comply with a NPDWR. As was noted in Section III of the August 6, 1998

Federal Register notice, blending is an option to reduce the cost of treatment when lower

removals are needed for compliance. A portion of the influent stream can be treated and blended

with an untreated portion to still meet the MCL. Under this scenario, both capital and operating

and maintenance costs would be lower than the estimates for the full stream treatment. Since

blending would lower the rate increase for water, household costs would be lower.

Another factor that would result in lower household costs is that the approach to establishing

the national-level affordability criteria assumes that all treatment costs are borne by the systems

and passed along to customers. The national-level affordability criteria do not consider the impact

of financial assistance from State Revolving Fund loans or Rural Utility Service. Loans or grants

would reduce the amortized capital costs in these systems. This would lead to lower impacts at

the household level in those systems that qualify for financial assistance. There are other

mitigating measures that can reduce the impact on households. Rate design, consolidation

strategies and regionalization approaches are discussed in Appendix F of the “National-Level

Affordability Criteria Under the 1996 Amendments to the Safe Drinking Water Act” report.
50

Table 7

 National-Level Affordability Criteria

System Size Baseline Affordability Available Expenditure

Population Served MHI

($/yr)

Water Bills

($/hh/yr)

Water Bills

 ( %MHI) 

Threshold

(2.5% MHI)

Margin

($/hh/year increase)

25 - 500 $30,785 $211 0.69% $770 $559

501 - 3,300 $27,058 $184 0.68% $676 $492

3,301 - 10,000 $27,641 $181 0.65% $691 $474
51

REFERENCES

USEPA. 1997a. Community Water System Survey Volume 1: Overview. EPA 815-R-97-001a. 

Washington, D.C.: EPA Office of Water. January 1997.

USEPA. 1997b. Community Water System Survey Volume II: Detailed Survey Result Tables

and Methodology Report. EPA 815-R-97-001b. Washington, D.C.: EPA Office of Water. 

January 1997.

USEPA. 1998a. Federal Register 63(151): 42032. August 6, 1998.

USEPA. 1998b. Small System Compliance Technology List for the Non-Microbial Contaminants

Regulated before 1996. EPA 815-R-98-002. Washington, D.C.: EPA Office of Water. 

September 1998.

USEPA. 1998c. Information for States on Developing Affordability Criteria for Drinking Water. 

EPA-816-R-98-002. Washington, D.C.: EPA Office of Water. February, 1998.

USEPA. 1998d. Federal Register. 63(157): 43834. August 14, 1998.

USEPA, 1998e. National-Level Affordability Criteria Under the 1996 Amendments to the Safe

Drinking Water Act. Prepared by International Consultants, Inc., Hagler Bailly Services, Inc. and

Janice A. Beecher, Ph.D. for the EPA. August 1998.

USEPA, 1998f. An Assessment of the Vulnerability of Non-Community Water Systems to

SDWA Cost Increases. Prepared by Science Applications International Corporation for the EPA. 

September 1998. 

USEPA, 1998g. Cost Evaluation of Small System Compliance Options: Point-of-Use and Pointof-Entry Treatment Units. Prepared by The Cadmus Group, Inc. for the EPA.. September 1998.
52

4.0 AFFORDABLE TECHNOLOGY DETERMINATIONS

Section 4.1: Overview

The two-stage screening process for variance technologies was described in Chapter 2. Only

5 of the 80 regulated contaminants passes through this screening process and remained eligible for

variance technologies. These five contaminants were: antimony, asbestos, atrazine, di-(2-

ethylhexyl) phthalate, and lindane. The national-level affordability criteria were described in

Chapter 3. Table 6 lists the derived criteria for each of the three size categories. This chapter

describes how the affordable technology determinations were made for these five contaminants.

Section 4.2: Results of SDWIS Run of Violations

The last screen in the two-stage screening process utilized the violation data in the Safe

Drinking Water Information System (SDWIS) to identify systems that might need to install

treatment to comply with one of the existing NPDWRs (EPA, 1997a). MCL violations were

found in SDWIS for the five contaminants that passed through the screening process. There were

142 MCL violations listed for these five contaminants. The breakdown was as follows: 34

violations for antimony, 6 for asbestos, 92 for atrazine, 8 for di-(2-ethylhexyl) phthalate and 2 for

lindane. The concentration listed in SDWIS as the MCL exceedance was examined for all 142

violations. The States were contacted to inquire about the compliance status of the system and to

verify the concentration reported in SDWIS. The compliance status was checked to see how

many of these systems had already complied with the NPDWR after the violation occurred. The

concentration listed in SDWIS was verified because several appeared to be reported using

incorrect units. Some values were reported in Fg/L instead of mg/L. It was important to get the

correct units for the violations because this data was used to estimate the removal efficiency

needed to comply with the NPDWR. Asbestos posed a unique problem since it has different units

than the other chemical regulations. The MCL for asbestos is measured in million fibers per liter

rather than milligrams per liter. For asbestos, violations had to be verified because some were

reported as fibers per liter instead of million fibers per liter. The asbestos violations were also

checked to determine the source of the asbestos. Asbestos can be found in the raw water entering

the treatment plant or it can occur from the corrosion of asbestos-cement pipe in the distribution

system. Different treatment technologies would be applied depending upon the source of the

asbestos.

The States indicated that 140 of the 142 systems were back in compliance with the

NPDWRs. The two systems that were not yet in compliance had violations of the asbestos

standard. The source of the asbestos in both of these systems was the corrosion of asbestoscement pipe. Even though the vast majority of the systems were back in compliance, the violation

data was used to determine if affordable compliance technologies existed for these five

contaminants. The concentrations for the highest violations (after verification of the units) were

used to compare with the MCL to determine the maximum removal efficiency needed for

compliance. This maximum removal efficiency was used to estimate treatment costs that were
53

compared with the national-level affordability criteria. If the treatment costs for one technology

were found to be affordable, then variance technologies were no longer available. This approach

is very conservative on the cost side because the worst-case system was used to determine the

removal efficiency.

For the five contaminants, the derived maximum removal efficiency exceeded 80 percent. 

Since most treatment technologies are generally capable of achieving removal efficiencies between

90 and 95 percent, treatment costs were based on this upper limit of performance. Thus, the costs

assume treatment of all of the water. Treatment of a portion of the influent water and blending it

with an untreated portion to reduce costs was not assumed in the development of the treatment

costs. When the concentration above the MCL is low enough, blending can be used to reduce

costs while still meeting the MCL. Both capital and operating and maintenance (O&M) costs can

be reduced by blending as described above. For the systems that do not need the maximum

removal efficiency, the treatment costs used to make the affordable technology determinations are

an overestimate of the costs their customers would see if a technology were installed for

compliance.

Section 4.3: Treatment Cost Models

The potential compliance technologies identified for these five contaminants included both

central treatment options and point-of-use (POU) options. Under the central treatment options,

all of the water supplied by the system is treated. Under the POU options, only the water at one

tap within a residence is treated. All of the other water in the house is not treated to reduce

contaminant concentrations. It was assumed that the kitchen tap would be treated for these

options.

For the central treatment options, three cost models were used to make treatment cost

estimates. The cost models have different ranges of applicability based on design flow. The

design flow is related to the production capacity of the treatment unit and is larger than the peak

daily flow for the system. The design flow is used to estimate capital costs for the system. The

average daily flow is used to make estimates for the O&M costs. Thus, the treatment unit is sized

based on production capacity and the operating costs are based on the volume of water being

treated for distribution.

The first cost model is for very small systems with a design flow below 270,000 gallons per

day. The document entitled “Very Small Systems Best Available Technology Document”

provides equations for estimating capital and O&M costs for these systems (EPA, 1993a). The

Water Model is a set of cost curves for various technologies contained in the document entitled

“Small System Water Treatment Costs (EPA, 1984). The third model is the WATERCO$T

model (Computer Software for Estimating Water and Wastewater Treatment Costs, Version 2.0,

1994). This is a computer model used for the estimation of costs for systems with flows larger

than 1 million gallons per day. The costing models generate discrete cost estimates corresponding

to specific design and average daily flow inputs.
54

A byproducts stream is produced by some of the technologies used to treat drinking water

contaminants. These byproducts streams are typically associated with the treatment of inorganic

contaminants. Coagulation/filtration and lime softening produce sludges that require disposal. 

Membrane technologies produce a concentrate stream. Ion exchange and activated alumina

produce brine streams. Two additional cost models are used to estimate the costs of disposal of

these residual byproduct streams. The document entitled “Small Water System Byproducts

Treatment and Disposal Cost Document” (EPA, 1993b) provides equations for capital and O&M

costs for technologies to dispose of residual byproducts. These cost equations are intended for

systems in the first two size categories (25 - 500 and 501 - 3,300 people). The equations for

capital and O&M costs for systems in the 3,301 - 10,000 people served category were taken from

the document entitled “Water System Byproducts Treatment and Disposal Cost Document”

(EPA, 1993c).

For the POU options, the document entitled “Cost Evaluation of Small System Compliance

Options: Point-of-Use and Point-of-Entry Treatment Units” (EPA, 1998a) was used. This

document contains capital and O&M cost equations for a variety of POU and POE options. 

Table 4.4.3 contains the data on total costs that was used to generate the equations for each of

the processes.

Section 4.4: Model Systems

As described in Section 4.3, the capital costs are based on design flow and the O&M costs

are based on average daily flow. The capital costs were amortized over 20 years at an interest

rate of 7%. The annualized capital costs were combined with the annual O&M costs to determine

the total production costs. The units for the total production cost are dollars per thousand gallons

($/kgal).

In order to derive capital and O&M costs for central treatment options, design and average

daily flows are needed for a typical system within each size category. The selected design and

average daily flows are based on the flows that were used in the regulations developed during the

early 1990s. The design and average daily flows for the five size categories that were used to

derive the flows for this analysis are contained in Table 8. For small systems, the design and

average daily flow are reported in thousand gallons per day (kgpd). Since the categories used in

the regulations are more stratified than the small system categories in the SDWA, a weighted

average of the flows was derived for each of the first two SDWA small system categories from

the data in Table 8. The number of systems within each size category in Table 8 was used for the

weighting factor in determining the flows for the SDWA categories. The design and average daily

flows used to derive costs for the affordable technology determinations are contained in Table 9.
55

Table 8

Design and Average Daily Flows Used for Regulations (early 1990s)

System Size Category

(population served)

Design Flow

(kgpd)

Average Daily Flow

(kgpd)

25 - 100 24 5.6

101 - 500 87 24

501- 1,000 270 86

1,001 - 3,300 650 230

3,301 - 10,000 1,800 700

Table 9

Design and Average Daily Flows Used for Affordable Technology Determinations

System Size Category

(population served)

Design Flow

(kgpd)

Average Daily Flow

(kgpd)

25 - 500 58 15

501 - 3,300 500 170

3,301 - 10,000 1,800 700

As discussed in Section 3.4.2, the centrally-managed point-of-use options is probably only

cost-effective in the 25 - 500 size category. In the POU/POE report (EPA, 1998a), costs for

POU and POE options were compared against central treatment costs. The costs for the

centrally-managed POU option had to be converted to the same flow basis for this comparison

and to make the affordable technology determinations. The cost estimates for the centrallymanaged POU treatment options are presented in dollars per thousand gallons used by the

household. This is very different than the cost per gallon treated by the POU device. By

converting the cost per gallon treated into the cost per thousand gallons used by the household,

the POU costs are comparable with central treatment costs. The breakpoint for POU options was

between 70 and 180 households depending upon the technology. The central treatment costs did

not include waste disposal costs. The inclusion of waste disposal would shift the breakpoint for

central treatment costs being cheaper than centrally-managed POU costs to a higher number of

households. It is unlikely that the centrally-managed POU would be more cost-effective than
56

central treatment after the 25 - 500 size category (upper bound of approximately 200

households). Due to increasing administrative costs and increasing coordination difficulties, it is

not expected that larger communities will find the implementation of centrally-managed POU or

POE devices to be cost-effective. However, affordable technology determinations were made for

the larger size categories.

The POU option cost equations use the number of households as the dependent variable. 

The subset of data from the Community Water Supply Survey (EPA, 1997a) that was used to

develop the baseline for current water bills also contained data on residential connections. This

data was used to determine the median number of residential connections within each size

category. The number of connections was assumed to be the number of households for each size

category. The POU costs were derived using the number of households in Table 10.

Table 10

Number of Households by Size Category for POU/POE Options

System Size Category

(population served)

Number of Residential Households

(Median for size category)

25 - 500 50

501 - 3,300 425

3,301 - 10,000 1935

Both the central treatment and the POU treatment costs provide the rate increase associated

with the installation of treatment. The treatment cost models produce rate increases measured in

dollars/thousand gallons ($/kgal). Annual household water consumption (kgal/year) is needed to

convert the treatment technology costs into the increase in annual household water bills. The

water consumption data in Table 2 were used with the cost increases derived by the models to

estimate annual household cost increases for each treatment technology. The water consumption

estimates in Table 2 were multiplied by 1.15 to account for lost water due to leaks. Since the

water lost to leaks is unbilled, the water bills for the actual water used were adjusted to cover this

lost water by increasing the household consumption. The adjusted consumption rates were then

multiplied by the rate increase imposed by treatment to determine the annual cost increase for the

household. This annual water bill increase was compared with the available expenditure margin to

determine if there was an affordable technology.

Section 4.5: Treatment Cost Estimates

Affordability only played a role in removing some of the options in the smallest size category. 

In the larger two size categories, all of the treatment technologies produced annual household

water bill increases below the available expenditure margin. However, in the smallest size
57

category, the centrally-managed POU option was typically the only affordable option. The cost

estimates for the centrally-managed POU options were all below $400 per household per year in

all of the size categories. For antimony, the only affordable treatment option was the centrallymanaged POU reverse osmosis option. For the three SOCs (atrazine, di-(2-ethylhexyl)phthalate,

and lindane), the centrally-managed POU granular activated carbon units were one of the two

technologies identified as affordable in the 25 - 500 size category. The other affordable

compliance technology was powdered activated carbon. This technology is only affordable when

the system already has a process train that includes basins, mixing, precipitation or sedimentation,

and filtration. Since the affordability of this technology is linked to existing treatment, the

centrally-managed POU GAC option is the only affordable option identified for the majority of

the systems in this size category. The affordable compliance technologies and the technologies

that did not pass the affordability criteria are identified in Table 11. For a detailed description of

the compliance technologies for the five contaminants, see the Compliance Technology List for

Non-Microbial Contaminants Regulated Before 1996 (EPA, 1998c).

Table 11

Affordable and Other Compliance Technologies in the 25 - 500 Size Category

Contaminant Affordable Compliance

Technologies

Other Compliance

Technologies

Antimony POU RO RO, C/F

Asbestos DF, DEF, CC C/F

Atrazine POU GAC, PAC GAC

di-(2-ethylhexyl) phthtalate POU GAC, PAC GAC

Lindane POU GAC, PAC GAC

KEY: POU = Point-of-Use RO = reverse osmosis

C/F = coagulation/filtration DF = direct filtration

DEF = diatomaceous earth filtration CC = corrosion control

PAC = powdered activated carbon (for plants with existing filtration)

GAC = granular activated carbon

As previously discussed, the worst-case system based on occurrence was selected to

determine the removal efficiency for treatment costs. Since many of the other systems that exceed

an MCL would need lower removals to comply with the MCL, other treatment alternatives may

be affordable through the use of blending. Systems and States should consider the technologies in

the “other compliance technologies” category when blending can be performed to reduce costs

while still meeting the MCL.
58

REFERENCES

CWC Engineering Software. 1994. W/W Costs and Design Criteria Guidelines (WATERCO$T

Model) User Manual for Computer Software for Estimating Water and Wastewater Treatment

Costs. Version 2.0.

EPA. 1984. Estimation of Small System Water Treatment Costs (Water Model). Cincinnati,

OH: EPA Office of Research and Development.

EPA. 1993a. Very Small Systems Best Available Technology Cost Document. Prepared by

Malcolm Pirnie, Inc. for the EPA. September 1993.

EPA. 1993b. Small Water System Byproducts Treatment and Disposal Cost Document. Draft

Final. Prepared by DPRA Inc. for the EPA. April 1993.

EPA. 1993c. Water System Byproducts Treatment and Disposal Cost Document. Draft Final. 

Prepared by DPRA Inc. for the EPA. April 1993.

EPA. 1997a. Unpublished data from the Safe Drinking Water Information System. Washington,

D.C.: EPA. December 16, 1997.

EPA, 1997b. Community Water System Survey Volume II: Detailed Survey Result Tables and

Methodology Report. EPA 815-R-97-001b. Washington, D.C.: EPA Office of Water. January

1997.

EPA. 1998a. Cost Evaluation of Small System Compliance Options: Point-of-Use and Point-ofEntry Treatment Units. Prepared by The Cadmus Group, Inc. for the EPA. September 1998.

EPA, 1998b. National-Level Affordability Criteria Under the 1996 Amendments to the Safe

Drinking Water Act. Prepared by International Consultants, Inc., Hagler Bailly Services, Inc. and

Janice A. Beecher, Ph.D. for the EPA. August 1998.

EPA, 1998c. Small System Compliance Technology List for the Non-Microbial Contaminants

Regulated before 1996. EPA 815-R-98-002. Washington, D.C.: EPA Office of Water. 

September 1998.
59

5.0 SUMMARY OF VARIANCE TECHNOLOGY FINDINGS FOR CONTAMINANTS

REGULATED BEFORE 1996

As previously discussed, compliance and variance technologies are mutually exclusive. The

two compliance technology lists developed by EPA for contaminants regulated before 1996

identified compliance technologies for all of the 80 regulated contaminants, including affordable

compliance technologies for all classes of small systems where appropriate. The two-stage

screening process removed all but five contaminants. Affordable compliance technologies were

identified for those five contaminants as discussed in Chapter 4. Thus, EPA will not, at this time,

be listing variance technologies for any existing NPDWR..

Because this is the first time that EPA has undertaken the variance technology analysis

required under the amended SDWA (which includes new findings concerning “affordability” and

“protectiveness”) and given the relatively short time for development of this analysis, EPA

considers the methodology described here and the resulting finding of no variance technologies to

be an initial screening effort, rather than a final determination of any kind. In addition, by enabling

EPA to list compliance and variance technologies rather than specifying them by regulation, the

statute specifically contemplates that this analysis (and any resulting list) will be subject to revision

based on new information and petitions from interested parties. EPA would be very interested in

suggestions from the public, and particularly from States, about how to improve the methodology

outlined here and discussed in the guidance and in variance technologies that EPA should consider

in revising and updating any future variance technology list. EPA identified several elements of

the methodology in this document that would undergo further review over the course of the next

year.

EPA stated in Chapter 2 that the procedures used to determine unreasonable risk to health

(URTH) values were under review. EPA will issue a revised guidance manual for determining

URTH as a result of that process. The URTH values listed in Table 1 will be modified or

recalculated using the new procedures for determining URTH values. The revised URTH values

for the 19 contaminants removed from consideration for variance technologies by the URTH

screen will be examined to see if there is a level above the MCL that may be protective of public

health for the expected useful life of a technology. Contaminants for which this screen is no

longer applicable would continue through the remainder of the screening process before

proceeding into the affordable compliance technology determination step.

EPA stated in Chapter 2 that it would re-examine the SDWIS violation data to see if

violations were reported for the contaminants removed by the “lack of violation” screen. There

were five contaminants removed by this screen. If MCL violations are found in a subsequent

SDWIS run, then the violation data would be used to determine if there is an affordable

compliance technology.

EPA indicated in Chapter 3 that a link was not established between baseline annual water

bills and existing treatment in the national-level affordability criteria. EPA will examine whether
60

this link should be established including an examination of the sample sizes. If a baseline for

treatment is deemed necessary, then separate baselines would need to made for each source type

because surface water systems should have a more extensive treatment technology baseline.

EPA will evaluate the comments that are received on the initial variance technology findings. 

If these evaluations indicate a need for variance technologies for the contaminants regulated

before 1996, then a list with variance technologies may be issued in August 1999; or sooner, if

warranted.
61

APPENDIX A

RELEVANT PARTS OF SECTION 1412 OF THE 1996 SDWA AMENDMENTS
62

SEC. 105. TREATMENT TECHNOLOGIES FOR SMALL SYSTEMS.

 Section 1412(b)(4)(E) (42 U.S.C. 300g-1(b)(4)(E)) is amended by 

adding at the end the following:

 ``(ii) List of technologies for small 

 systems.--The Administrator shall include in the 

 list any technology, treatment technique, or other 

 means that is affordable, as determined by the 

 Administrator in consultation with the States, for 

 small public water systems serving--

 ``(I) a population of 10,000 or 

 fewer but more than 3,300;

 ``(II) a population of 3,300 or 

 fewer but more than 500; and

 ``(III) a population of 500 or fewer 

 but more than 25;

 and that achieves compliance with the maximum 

 contaminant level or treatment technique, 

 including packaged or modular systems and point-

 of-entry or point-of-use treatment units. Point-

 of-entry and point-of-use treatment units shall be 

 owned, controlled and maintained by the public 

 water system or by a person under contract with 

 the public water system to ensure proper operation 

 and maintenance and compliance with the maximum 

 contaminant level or treatment technique and 

 equipped with mechanical warnings to ensure that 

 customers are automatically notified of 

 operational problems. The Administrator shall not 

 include in the list any point-of-use treatment 

 technology, treatment technique, or other means to 

 achieve compliance with a maximum contaminant 

 level or treatment technique requirement for a 

 microbial contaminant (or an indicator of a 

 microbial contaminant). If the American National 

 Standards Institute

[[Page 110 STAT. 1626]]

 has issued product standards applicable to a 

 specific type of point-of-entry or point-of-use 

 treatment unit, individual units of that type 

 shall not be accepted for compliance with a 
63

 maximum contaminant level or treatment technique 

 requirement unless they are independently 

 certified in accordance with such standards. In 

 listing any technology, treatment technique, or 

 other means pursuant to this clause, the 

 Administrator shall consider the quality of the 

 source water to be treated.

 ``(iii) List of technologies that achieve 

 compliance.--Except as provided in clause (v), not 

 later than 2 years after the date of enactment of 

 this clause and after consultation with the 

 States, the Administrator shall issue a list of 

 technologies that achieve compliance with the 

 maximum contaminant level or treatment technique 

 for each category of public water systems 

 described in subclauses (I), (II), and (III) of 

 clause (ii) for each national primary drinking 

 water regulation promulgated prior to the date of 

 enactment of this paragraph.

 ``(iv) Additional technologies.--The 

 Administrator may, at any time after a national 

 primary drinking water regulation has been 

 promulgated, supplement the list of technologies 

 describing additional or new or innovative 

 treatment technologies that meet the requirements 

 of this paragraph for categories of small public 

 water systems described in subclauses (I), (II), 

 and (III) of clause (ii) that are subject to the 

 regulation.

 ``(v) <<NOTE: Records.>> Technologies that 

 meet surface water treatment rule.--Within one 

 year after the date of enactment of this clause, 

 the Administrator shall list technologies that 

 meet the Surface Water Treatment Rule for each 

 category of public water systems described in 

 subclauses (I), (II), and (III) of clause (ii).''.
64

SEC. 111. TECHNOLOGY AND TREATMENT TECHNIQUES.

 (a) Variance Technologies.--Section 1412(b) (42 U.S.C. 300g-1(b)) is 

amended by adding the following new paragraph after paragraph (14):

 ``(15) <<NOTE: Regulations.>> Variance technologies.--

 ``(A) In general.--At the same time as the 

 Administrator promulgates a national primary drinking 

 water regulation for a contaminant pursuant to this 

 section, the Administrator shall issue guidance or 

 regulations describing the best treatment technologies, 

 treatment techniques,

[[Page 110 STAT. 1632]]

 or other means (referred to in this paragraph as 

 `variance technology') for the contaminant that the 

 Administrator finds, after examination for efficacy 

 under field conditions and not solely under laboratory 

 conditions, are available and affordable, as determined 

 by the Administrator in consultation with the States, 

 for public water systems of varying size, considering 

 the quality of the source water to be treated. The 

 Administrator shall identify such variance technologies 

 for public water systems serving--

 ``(i) a population of 10,000 or fewer but more 

 than 3,300;

 ``(ii) a population of 3,300 or fewer but more 

 than 500; and

 ``(iii) a population of 500 or fewer but more 

 than 25,

 if, considering the quality of the source water to be 

 treated, no treatment technology is listed for public 

 water systems of that size under paragraph (4)(E). 

 Variance technologies identified by the Administrator 

 pursuant to this paragraph may not achieve compliance 

 with the maximum contaminant level or treatment 

 technique requirement of such regulation, but shall 

 achieve the maximum reduction or inactivation efficiency 

 that is affordable considering the size of the system 

 and the quality of the source water. The guidance or 

 regulations shall not require the use of a technology 

 from a specific manufacturer or brand.

 ``(B) Limitation.--The Administrator shall not 
65

 identify any variance technology under this paragraph, 

 unless the Administrator has determined, considering the 

 quality of the source water to be treated and the 

 expected useful life of the technology, that the 

 variance technology is protective of public health.

 ``(C) Additional information.--The Administrator 

 shall include in the guidance or regulations identifying 

 variance technologies under this paragraph any 

 assumptions supporting the public health determination 

 referred to in subparagraph (B), where such assumptions 

 concern the public water system to which the technology 

 may be applied, or its source waters. The Administrator 

 shall provide any assumptions used in determining 

 affordability, taking into consideration the number of 

 persons served by such systems. The Administrator shall 

 provide as much reliable information as practicable on 

 performance, effectiveness, limitations, costs, and 

 other relevant factors including the applicability of 

 variance technology to waters from surface and 

 underground sources.

 ``(D) Regulations and guidance.--Not later than 2 

 years after the date of enactment of this paragraph and 

 after consultation with the States, the Administrator 

 shall issue guidance or regulations under subparagraph 

 (A) for each national primary drinking water regulation 

 promulgated prior to the date of enactment of this 

 paragraph for which a variance may be granted under 

 section 1415(e). The Administrator may, at any time 

 after a national primary drinking water regulation has 

 been promulgated, issue guidance or regulations 

 describing additional variance technologies. The 

 Administrator shall, not less often than

[[Page 110 STAT. 1633]]

 every 7 years, or upon receipt of a petition supported 

 by substantial information, review variance technologies 

 identified under this paragraph. The Administrator shall 

 issue revised guidance or regulations if new or 

 innovative variance technologies become available that 

 meet the requirements of this paragraph and achieve an 

 equal or greater reduction or inactivation efficiency 

 than the variance technologies previously identified 
66

 under this subparagraph. No public water system shall be 

 required to replace a variance technology during the 

 useful life of the technology for the sole reason that a 

 more efficient variance technology has been listed under 

 this subparagraph.''.

 (b) Availability of Information on Small System Technologies.--

Section 1445 (42 U.S.C. 300j-4) is amended by adding the following new 

subsection after subsection (g):

 ``(h) Availability of Information on Small System Technologies.--For 

purposes of sections 1412(b)(4)(E) and 1415(e) (relating to small system 

variance program), the Administrator may request information on the 

characteristics of commercially available treatment systems and 

technologies, including the effectiveness and performance of the systems 

and technologies under various operating conditions. The Administrator 

may specify the form, content, and submission date of information to be 

submitted by manufacturers, States, and other interested persons for the 

purpose of considering the systems and technologies in the development 

of regulations or guidance under sections 1412(b)(4)(E) and 1415(e).''.
67

APPENDIX B

RELEVANT PARTS OF SECTION 1415 OF THE 1996 SDWA AMENDMENTS
68

SEC. 116. SMALL SYSTEMS VARIANCES.

 Section 1415 (42 U.S.C. 300g-4) is amended by adding at the end the 

following:

 ``(e) Small System Variances.--

 ``(1) In general.--A State exercising primary enforcement 

 responsibility for public water systems under section 1413 (or 

 the Administrator in nonprimacy States) may grant a variance 

 under this subsection for compliance with a requirement 

 specifying a maximum contaminant level or treatment technique 

 contained in a national primary drinking water regulation to--

 ``(A) public water systems serving 3,300 or fewer 

 persons; and

 ``(B) with the approval of the Administrator 

 pursuant to paragraph (9), public water systems serving 

 more than 3,300 persons but fewer than 10,000 persons,

 if the variance meets each requirement of this subsection.

 ``(2) Availability of variances.--A public water system may 

 receive a variance pursuant to paragraph (1), if--

 ``(A) the Administrator has identified a variance 

 technology under section 1412(b)(15) that is applicable 

 to the size and source water quality conditions of the 

 public water system;

 ``(B) the public water system installs, operates, 

 and maintains, in accordance with guidance or 

 regulations issued by the Administrator, such treatment 

 technology, treatment technique, or other means; and

 ``(C) the State in which the system is located 

 determines that the conditions of paragraph (3) are met.

 ``(3) Conditions for granting variances.--A variance under 

 this subsection shall be available only to a system--

 ``(A) that cannot afford to comply, in accordance 

 with affordability criteria established by the 

 Administrator (or the State in the case of a State that 

 has primary enforcement responsibility under section 

 1413), with a national primary drinking water 

 regulation, including compliance through--

 ``(i) treatment;

[[Page 110 STAT. 1642]]

 ``(ii) alternative source of water supply; or

 ``(iii) restructuring or consolidation (unless 
69

 the Administrator (or the State in the case of a 

 State that has primary enforcement responsibility 

 under section 1413) makes a written determination 

 that restructuring or consolidation is not 

 practicable); and

 ``(B) for which the Administrator (or the State in 

 the case of a State that has primary enforcement 

 responsibility under section 1413) determines that the 

 terms of the variance ensure adequate protection of 

 human health, considering the quality of the source 

 water for the system and the removal efficiencies and 

 expected useful life of the treatment technology 

 required by the variance.

 ``(4) Compliance schedules.--A variance granted under this 

 subsection shall require compliance with the conditions of the 

 variance not later than 3 years after the date on which the 

 variance is granted, except that the Administrator (or the State 

 in the case of a State that has primary enforcement 

 responsibility under section 1413) may allow up to 2 additional 

 years to comply with a variance technology, secure an 

 alternative source of water, restructure or consolidate if the 

 Administrator (or the State) determines that additional time is 

 necessary for capital improvements, or to allow for financial 

 assistance provided pursuant to section 1452 or any other 

 Federal or State program.

 ``(5) <<NOTE: Review.>> Duration of variances.--The 

 Administrator (or the State in the case of a State that has 

 primary enforcement responsibility under section 1413) shall 

 review each variance granted under this subsection not less 

 often than every 5 years after the compliance date established 

 in the variance to determine whether the system remains eligible 

 for the variance and is conforming to each condition of the 

 variance.

 ``(6) Ineligibility for variances.--A variance shall not be 

 available under this subsection for--

 ``(A) any maximum contaminant level or treatment 

 technique for a contaminant with respect to which a 

 national primary drinking water regulation was 

 promulgated prior to January 1, 1986; or

 ``(B) a national primary drinking water regulation 

 for a microbial contaminant (including a bacterium, 

 virus, or other organism) or an indicator or treatment 

 technique for a microbial contaminant.
70

 ``(7) Regulations and guidance.--

 ``(A) In general.--Not later than 2 years after the 

 date of enactment of this subsection and in consultation 

 with the States, the Administrator shall promulgate 

 regulations for variances to be granted under this 

 subsection. The regulations shall, at a minimum, 

 specify--

 ``(i) procedures to be used by the 

 Administrator or a State to grant or deny 

 variances, including requirements for notifying 

 the Administrator and consumers of the public 

 water system that a variance is proposed to be 

 granted (including information regarding the 

 contaminant and variance) and requirements for a 

 public hearing on the variance before the variance 

 is granted;

[[Page 110 STAT. 1643]]

 ``(ii) requirements for the installation and 

 proper operation of variance technology that is 

 identified (pursuant to section 1412(b)(15)) for 

 small systems and the financial and technical 

 capability to operate the treatment system, 

 including operator training and certification;

 ``(iii) eligibility criteria for a variance 

 for each national primary drinking water 

 regulation, including requirements for the quality 

 of the source water (pursuant to section 

 1412(b)(15)(A)); and

 ``(iv) information requirements for variance 

 applications.

 ``(B) <<NOTE: Publication.>> Affordability 

 criteria.--Not later than 18 months after the date of 

 enactment of the Safe Drinking Water Act Amendments of 

 1996, the Administrator, in consultation with the States 

 and the Rural Utilities Service of the Department of 

 Agriculture, shall publish information to assist the 

 States in developing affordability criteria. The 

 affordability <<NOTE: Review.>> criteria shall be 

 reviewed by the States not less often than every 5 years 

 to determine if changes are needed to the criteria.

 ``(8) Review by the administrator.--
71

 ``(A) In general.--The Administrator shall 

 periodically review the program of each State that has 

 primary enforcement responsibility for public water 

 systems under section 1413 with respect to variances to 

 determine whether the variances granted by the State 

 comply with the requirements of this subsection. With 

 respect to affordability, the determination of the 

 Administrator shall be limited to whether the variances 

 granted by the State comply with the affordability 

 criteria developed by the State.

 ``(B) Notice and publication.--If the Administrator 

 determines that variances granted by a State are not in 

 compliance with affordability criteria developed by the 

 State and the requirements of this subsection, the 

 Administrator shall notify the State in writing of the 

 deficiencies and make public the determination.

 ``(9) Approval of variances.--A State proposing to grant a 

 variance under this subsection to a public water system serving 

 more than 3,300 and fewer than 10,000 persons shall submit the 

 variance to the Administrator for review and approval prior to 

 the issuance of the variance. The Administrator shall approve 

 the variance if it meets each of the requirements of this 

 subsection. The Administrator shall approve or disapprove the 

 variance within 90 days. If 

 the <<NOTE: Notification.>> Administrator disapproves a variance 

 under this paragraph, the Administrator shall notify the State 

 in writing of the reasons for disapproval and the variance may 

 be resubmitted with modifications to address the objections 

 stated by the Administrator.

 ``(10) Objections to variances.--

 ``(A) By the administrator.--The Administrator may 

 review and object to any variance proposed to be granted 

 by a State, if the objection is communicated to the 

 State not later than 90 days after the State proposes to 

 grant the variance. <<NOTE: Notification.>> If the 

 Administrator objects to the granting of a variance, the 

 Administrator shall notify the State in writing of each 

 basis for the objection and propose a

[[Page 110 STAT. 1644]]

 modification to the variance to resolve the concerns of 

 the Administrator. The State shall make the recommended 
72

 modification or respond in writing to each objection. If 

 the State issues the variance without resolving the 

 concerns of the Administrator, the Administrator may 

 overturn the State decision to grant the variance if the 

 Administrator determines that the State decision does 

 not comply with this subsection.

 ``(B) Petition by consumers.--Not later than 30 days 

 after a State exercising primary enforcement 

 responsibility for public water systems under section 

 1413 proposes to grant a variance for a public water 

 system, any person served by the system may petition the 

 Administrator to object to the granting of a variance. 

 The Administrator shall respond to the petition and 

 determine whether to object to the variance under 

 subparagraph (A) not later than 60 days after the 

 receipt of the petition.

 ``(C) Timing.--No variance shall be granted by a 

 State until the later of the following:

 ``(i) 90 days after the State proposes to 

 grant a variance.

 ``(ii) If the Administrator objects to the 

 variance, the date on which the State makes the 

 recommended modifications or responds in writing 

 to each objection.''.