SMALL SYSTEM
COMPLIANCE TECHNOLOGY
LIST FOR THE STAGE I DBF RULE (FINAL REPORT)
STANDARDS AND RISK REDUCTION BRANCH
STANDARDS AND RISK MANAGEMENT DIVISION
OFFICE OF GROUND WATER AND DRINKING WATER
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C
TASK ORDER PROJECT OFFICER: WILLIAM HAMELE
NOVEMBER 1998
INTERNATIONAL CONSULTANTS, INC
4134 Linden Ave* Suite 200
Dayton, OH 45432
Under Contract with the USEPA No. 68-C6-M39
Delivery Order No.S, Modification No. 3 - Task *6
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.ACKNOWLEDGMENTS
The Office of Ground Water and Drinking Wa'er, Standards and Risk Reduction Branch.
Standards and Risk Management Division prepares this uocument. The Task Order Project Officer
was Mr William Hamele of the U.S. Environmental Protection Agency.
Technical consultant, International Consultants, Incorporated played a significant rolt in the
preparation of this document. The Technical Project Manager was Michael T. Cowles of
International Consultants, Inc. The Project Manager was Ronald Braun of International Consultants,
Inc. Members of the International Consultants technical support team were Christopher Hill, and Tim
Soward.
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TABLE OF CONTENTS
Page:
1.0 INTRODUCTION
1.1 Safe Drinking Water Act Implementation 1
1.2 Need for a Small System Technology Requirement 1
1.3 Small System Treatment technology Requirements of the 1996 SDWA 2
1.4 Affordability of Compliance Technologies 3
1.5 The SDWAandtheDBP Rule : 3
1.6 Format of the Small System Compliance Technology List for the
Stage 1 DBF Rule 6
1.7 Content of the Small System Compliance Technology List for the
'Stage 1 DBF Rule 6
1.8 Purpose of the Document 7
1.9 Document Organization 7
2.0 COMPLIANCE TECHNOLOGY LIST FOR THE STAGE I
DBF RULE , _ 8
2.1 Selection of a Compliance Technology 8
'2.2 List of Evaluated Technologies 8
2.2.1 List of Technologies for Removal of DBF Precursors ^ — 9
2.2.2 List of Alternative Disinfection Schemes for DBF Control 9
2.2.3 List of DBF Removal Technologies 10
2.2.3.1 Point-of-Entry (FOE)/ Ppint-of-Use (POU) Removal
ofDBPs '. ,10
* _ i.
3.0 COMPLIANCE TECHNOLOGY DESCRIPTIONS 11
3.1 Compliance Descriptions for Precursor Removal Technologies 11
3.1.1 Enhw*** Coagulation 11
3.1.2 Enhanced Preciprtative Softening 13
3.1.3 Granular Activated Carbon 14
3.1.4 Membrane Processes IS
3.2 Compliance Evaluation of Alternate Disinfection Technologies 16
3.2.1 .Moving the Point of Chlorination 17
3.2.2 Chloramines as a Secondary Disinfectant 17
3.2.3 Ozonation as a Primary Disinfectant ...; .. 18
3.2.4 Chlorine Dioxide as a Primary Disinfectant ...: —, 19
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3 3 Compliance Evaluation of Disinfection B>-Products Removal and Control
of Disinfectant Residuals . 20
331 Compliance Technology Evaluation of POE/POU Devices . 20
3.31.1 Point-of-Entry Devices .... 20
3.3.1.2 Point-of-UseDevices • 21
3.3 2 POE/POU Reverse Osmosis Devices t 22
3 3.3 POE/POU Granular Activated Carbon Devices 23
i
4.0 BASIS FOR COMPOSITE COST ESTIMATES 25
4.1 Introduction • 25
5.0 AFFORD ABILITY ASSESSMENT 31
5.1 ' Introduction 31
5.2 Role of National-Level Affordability Criteria ! 31
5.3 Unit of Measure for the National-Level Affordability Criteria 32
5.4 Derivation of the National-Level of Affordability Criteria 33
5.4.1 Derivation of the Affordability Threshold 35
5.5 Determination of Household Affordability 37
6.0 REFERENCES ' '...!." 52
APPENDIX A; Relevant Parts of Section 1412 of the 1996 SDWA Amendments ..... 58
APPENDIX B Relevant Parts of Section* 1415 of the 1996 SDWA Amendments 64
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LIST OF TABLES
. Page:
1.0 INTRODUCTION 1
Table 1-1 Maximum Contaminant Levels for D/DBP 5
Table 1-2 Maximum Residual Disinfectant Levels for D/DBP 6
2.0 LIST OF EVALUATED COMPLIANCE TECHNOLOGIES 8
3.0 COMPLIANCE TECHNOLOGY DESCRIPTIONS 11
4.0 BASIS FOR COMPOSITE COST ESTIMATES 25
Table 4-1 US EPA Flow Categories (Small Systems) 25
Table 4-2 Flow Categories Used for the Development of Composite Costs 26
Table 4-3 Number of Households by Size Category for POU/POE Options 26
Table 4-4 Composite Cost for Technologies Examined for
Removal of DBP Precursors 27
Table 4-5 Composite Cost for Alternative Disinfectants Schemes
For DBP Control 28
Table 4-6 Composite Cost for DBP Removal Technologies 30
5.0 AFFORDABILITY DETERMINATIONS 31
Table 5-1 Residential Consumption at Small Water Systems " 33
Table 5-2 National Level Affordability Criteria ; 34
Table 5-3 Summary of Select Consumer Expenditure for All Consumer Units .... 35
Table 5-4 Affordability Assessment of Technologies Examined for
Removal of DBP Precursors 38
Table 5-5 Afibrdabffity Assessment of Alternative Disinfectants
Schemes for DBP Control .39
Table 5-6 Afibfdabffity Assessment of Technologies Examined for
DBP Removal \ '. '.... 42
Table 5-7a Stage 1 DBP Compliance Technologies Deemed Affordable
(Population Size Ranging from 25 - 500) 44
Table 5-7b Stage 1 DBP Compliance Technologies Deemed Affordable
(Population Size Ranging from 501 -10,000) 46
Table 5-8 Stage 1 DBP Compliance Technologies Deemed Not Affordable
(Population Size Ranging from 25 - 500) ! 49
Table 5-9 Stage 1 DBP Technologies Deemed Affordable But Not Included as
Compliant Technologies (Population Size Ranging from 25 -10,000) .. 50
Table 5-10 Stage 1 DBP Emerging Technologies Deemed Non-Affordable
(Population Size Ranging from 25 - 500) 51
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LIST OF EXHIBITS
Page:
1.0 INTRODUCTION l
Exhibit
1 1 Affordable Compliance Technologies 4
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1.0 INTRODUCTION
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 United States
Environmental Protection Agency (US EPA). The Amendments contain a challenging set of activities
for the US 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 the US
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 the US
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) the list of technologies that small systems can use to comply with the Surface Water
Treatment Rule (SWTR), completed August 6,1997; (2) the list of technologies that small systems
can use to comply with all of the other National Primary Drinking Water Regulations (NPDWRs),
by August 6,1998; and (3) the list of variance technologies for small systems for the appropriate
NPDWRs, by August 6,1998. 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.
This document relates to the first of the long-term goals: the preparation of a small system compliance
technologies list for the Stage 1 Disinfection Byproducts Rule.
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)(4XD)]. 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.
Before the 1996 Amendments, cost assessments for the treatment technology feasibility
determinations were based upon impacts to regional and large metropolitan water systems. This
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protocol uas established when the SDWA w,as ongmally enacted in 1974 [H R. Rep No 93-1185
at 18( 1974)] and was carried over when the Act was amended in 1986 [132 Cong. Rec S6287 (May
-\. 1986)] The population size categories that the US 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 in part
through the previously described series of small system compliance technologies; this.guidance is the
part of a series of publications (begun in 1997 for the SWTR) aimed at helping small systems comply
with drinking water standards.
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 treatment' techniques require further analysis for small system applications. The
1996 SDWA specifically requires the US EPA to make technology assessments relevant to the three
categories of small systems for. both existing regulations (e.g., SWTR and TCR) and future
requirements. The three population-based 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 smaO 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-emry (POE) or point-of-use (POU) treatment
units [see Section 1412(bX4XEXii)]. Variance technologies are only specified for those system
size/source water quality combinations for which there are no listed compliance technologies [Section
1412(bX 15XA)]. 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 ueauucui technique requirement, they
must achieve the maximum reduction or inac&vation efficiency that is affordable considering the size
of the system and the quality of the source water. Variance technologies must also achieve a level
of contaminant reduction that is protective of public health [Section 1412(bX15XB)]. Appendix A
of this document includes relevant pans of Section 1412 of the 1996 SDWA Amendments.
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 fewer than 10.000): this is the "small system variance" The
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between a regular variance and a small system^anance is the basis for the feasibilit\
i technical and affordabiliry) 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 US 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 141 S(eX2XA)]. A small system variance may only be obtained if alternate source, treatment,
and restructuring options are unaffordable at the system-level.
There are additional SDWA requirements that affect the listing of variance technologies
Critical in regard to this particular listing are the following: (1) small system variances are hot
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)];
and, (2) small system variances are not available for regulations addressing microbiological
contamination (including contamination by bacteria, viruses, or other organisms) or any indicator or
treatment technique for a microbial contaminant [Section 1415(eX6XB)]. Variance technologies will
not be listed for NPDWRs relevant to these restricted contaminants. Appendix B of this document
includes relevant parts of Section 1415 of the 1996 SDWA Amendments.
1.4 Aflbrdability of Compliance Technologies
The two major concerns regarding the specification of SDWA compliance technologies for
small systems are affordability and technical complexity: Small systems typically cannot achieve the
economies of scale available to large systems and thus costs per thousand gallons treated or
.household tend to be higher. As a result of the higher costs and technical complexity of many
compliance technologies, some small systems cannot afford to install and operate a prescribed
technology. Under the Stage 1 Disinfection Byproducts Rule (DBPR), affordable compliance
technologies must be identified. Chapter 5 of this document outlines the affordability criteria used
in the identification of affordable technologies. Exhibit 1.1 is a flowchart outlining the role, of
national-level affordability criteria in the identification of BATs (US EPA, 1998b).
1.5 The SDWA and the DBF Rote
In 1986 Congress passed an Amendment to the SDWA, requiring the US EPA to set
Maximum Contaminant Level Goals (MCLGs) for many contaminants found in drinking water.
These MCLGs must provide an adequate margin of safety from contaminant concentrations that are
known or anticipated to induce adverse effects on human health. For each contaminant, the US EPA
must establish a Maximum Contaminant Level (MCL) that is as close to the MCLG as is feasible with
the use of best available technology (BAT). Although the BAT identified for each contaminant must
be an economically feasible and proven technology under field conditions, systems are not required
to install BAT for purposes of meeting a corresponding MCL. If analytical techniques are not
economically or technologically feasible for a given contaminant, then the US EPA must set a
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Exhibit l.l
Affordable Compliance Technologies*
SystemSoft of
Compliance j
CM Synem Afford
Treatment. Alt Source or
Can Syum Afford \ No
a
Technology?
Implement
Compliance;
Technology
PwtodRunOm?
Note: -hsappioich eownttw Rigulittonsttat pasialof trw msmaning cnto* fervtitanct twhnologiea
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::=.'.:T.cr.t :e:hmjue rbr that contaminant in lieu ofan'MCL The treatment technique must, in the
IS EP-\ s judgement, be capable of providing economically feasible reduction of human health risks
Acting on the 1986 Amendments, the US EPA developed a list of disinfectants and
disinfection by-products for possible regulation. This list was further refined based upon available
data indicating the potential of specific DBFs to pose significant health risk at levels that occur in
drinking waters The US EPA released an Overview of Anticipated General Requirements and Major
Issues for the D/DBP Rule on June 2.1, 1991. That document provided a list of DBFs which could
be regulated with MCLs, including trihalomethanes, haloacetic acids, chloral hydrate; bromate, and
chlorate. Disinfectants were also listed, including chlorine, chloramines and chlorine dioxide.
Industry comment on the 1991 overview was significant and prompted the US EPA to
conduct a regulatory negotiation, which took place among stakeholders in 1992-1993. Following
the negotiation, the US EPA proposed the Stage 1 Disinfection Byproducts Rule (DBPR) in 1994
In 1996, Congress further amended the SDWA, thereby changing the number of contaminants which
must be regulated, the manner in which regulations are set, and providing direction for water utility
initiatives such as providing consumer confidence reports and focusing on watershed management.
The standard setting process was modified to consider cost-benefit analysis, in an attempt to better
quantify the value of the regulatory process. The amendments established deadlines for finalizing the
Stage 1 DBPR by May, 2002.
The US EPA convened regulatory negotiation group in 1997. This group confirmed the
findings from the 1994 proposal with some minor modifications. The Stage 1 DBPR was finalized
in November, 1998. The first stage of the DBPR includes MCLs for TTHMs, HAAS, chlorite and
bromate (see' Table 1-1). Maximum residual disinfectant levels (MRDLs) are also included for
chlorine, chloramines and chlorine dioxide (see Table 1-2). A treatment technique is included for
conventional treatment plants with sedimentation and nitration as well as preciphative softening plants
with'filtration.
Table 1-1
Maximum Contaminant Levels for D/DBP
Total TrihaJoronlumM (TTHMs)
Hakaoetic Acids (HAAS)
Bromate
Chlorite
0.080
0.060
0.010
: " 1.0
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Table 1-2
Maximum Residual Disinfectant Levels for D/DBP
Coopewd
Chlorine (as Cl,)
Chloramine
Chlorine Dioxide (as CIO,)
MRDLs dag/I*)
StttttDKPR
4.0
4.0
0.8
1.6 Format of the Small System Compliance Technology List for the Stage 1 DBF Rule
The 1996 SDWA does not specify the format for the compliance technology lists. Section
1412(b)(15XD) states that the variance technology lists can be issued either through guidance or
regulations. The US EPA believes that the compliance technology list may also be appropriately
provided through guidance rather than through rule-making. Since the listing provided in this
guidance is meant to be informational and interpretative, it does not require any changes to existing
rules or the promulgation of new ones. The purpose of this guidance is to provide small systems with
information concerning the types of technologies that can be used to comply with the Stage 1 DBPR
requirements; it does not over-ride any of the regulatory requirements.
1.7 Content of the Small System Compliance Technology List for the Stage 1 DBF Rule
The SDWA does not specify the content of the compliance technology lists. This listing
provides great detail on the capabilities, applicability ranges, water quality concerns, and operational
and maintenance requirements for .the identified compliance technologies.
The listing will evolve over time or as required. The listing will not be product-specific
because the US EPA's Office of Ground Water and Drinking Water does not have the resources to
review each product for each potential application and since this would be beyond the US EPA's
purview. Information on specific products may be available through other mechanisms:
(1) the US EPA's Office of Research and Development and the National Sanitation Foundation
International (NSF) are conducting a pilot project under the Environmental Technology Verification
(ETV) Program designed to provide treatment purchasers with performance data from independent
third party organizations.. The US EPA and NSF are cooperatively conducting this project to provide
the mechanism for "verification testing" of packaged drinking water treatment systems for .community
and commercial needs. This pilot project includes: development of verification protocols and test
plans; independent testing and validation of packaged equipment; partnerships among test/verification
entities to obtain credible cost and performance data; and preparation of product verification reports
for wide-spread distribution. It will .be through the distribution of this data by which the US EPA
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the greatest amount of performance information sharing, leading to efficient and effective
technolog> applications to meet safe drinking water goals (For more information on this project
consult the NSF-ETV Web site hup: -www. nsf.org verification verification.html)
(2) The National Drinking Water Clearinghouse, at West Virginia University, has developed the
RESULTS database. RESULTS was designed as an electronic means to access data'on small water
treatment systems employing both conventional and non-conventional treatment technologies.
Information and on-site contacts may be obtained on these treatment applications. (Clearinghouse:
phone (304)293-4191, or Web site http://www.ndwc.wvu.edu)
1.8 Purpose of the Document
The purpose of this document is to evaluate the applicability and affordability of DBF control
technologies for small systems. Unit costs were developed for applicable technologies in the
Technologies and Costs Document for Control of Disinfection Byproducts (US EPA, 1998c) and the
Technologies and Costs Document for Point-of-Entty and Point-of-Use Devices for Control of
Disinfection Byproducts (US EPA, 1998d). This document discusses the capabilities of each
technology for DBF control and determines whether they are affordable (as defined earlier in this
chapter) for small water systems in the three categories defined by the 1996 SDWA Amendments.
1.9 Document Organization
This document is organized according to the following sections:
• Section 2 - Lilt of Evaluated Compliance Technologies: provides updated
information on the .Stage 1DBPR and the technologies evaluated for the compliance
listing.
• Section 3 - Compliance Technology Descriptions: provides an in-depth evaluation
of technologies listed -for compfance' including evaluation of capabilities and
operation.
• Section 4 -Bash for Composite Cost Tarimalrr provides background on composite
cost generation as well as.the actual composite cost by technology.
• Section 5 - Aftbrdabflfty Determinations: provides background information and
determinations regarding the affordability of technologies per criteria established
under the SDWA.
• Section 6 - Break-Point Analysis: details the established break-points between the
• Utilization Of POE/POU dffldm *qre qthf CTHTHT"* fMitgdfayl treatment options
• Section 7 - References: provides the citations used in the preparation of this
document.
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2.0 LIST OF E\ ALLATED COMPLLANCE TECHNOLOGIES
2.1 Selection of a Compliance Technology
»
The selection of a compliance strategy is dependent on specific parameters at an individual
plant (e.g source water quality).. The following factors, as outlined in the 1998 DBF Technologies
&Cost Document, should be considered when selecting a DBF compliance strategy:
>
• Quality of the water source, particularly concentrations of those species that exert an
oxidant demand or require disinfection (e.g., NOM, microbiological contaminants,
bromide, reduced metals and odor causing contaminants).
• Impacts of the strategy on microbiological quality in the plant and in the distribution
system. • • •
• Impacts of the strategy on other treatment processes (e.g. nitration).
• Economies of scale and the economic stability of the community being served.
• Waste disposal requirements.
Prior to selection of a treatment alternative, engineering studies and/or pilot, plant investigations may
be required to determine the level of DBF control provided by various treatment technology
alternatives. The following generic treatment strategies were identified in the 1998 DBF
Technologies &Costs for control of organic DBFs:
• Remove as much NOM from the raw water as feasible prior to the addition of
chemical oxidants or disinfectants.
• Use alternative oxidants .or disinfectants .that do not create DBFs at levels considered
adverse to hm*nft health.
• Remove DBFs after they are formed.
\
The first alternative is considered to be the most efficient and cost effective means of controlling
organic DBFs. The second alternative may cause a reduction m certain DBFs whfle increasing the
formation of others. The third alternative may not remove all DBFs of concern. Further, there is a
risk of DBF formation in the distribution system from the reaction of a secondary disinfectant and
NOM if the third alternative is not utilized in tandem with a NOM removal step. -
2.2 List of Evaluated technologies
Evaluated technologies are grouped into three areas. They are: 1) technologies for precursor
removal; 2) use of alternative disinfection schemes, and 3) technologies for removal of DBFs after
they are formed. The 1998 DBF Technologies & Costs document notes that it is more cost effective
to remove DBF precursor material than to remove DBFs after they are formed. The discussion of
technologies for removal of DBFs (post formation) is therefore limited to Point-of-Entry and Point-
of-use devices because they are generally the only cost effective DBF removal alternatives available
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. Each or" the technologies listed in this chapter is discussed in more detail in Chapter 3 The
unit costs and affordability determinations are presented in Chapter 4 and 5
2.2. 1 List of Technologies for Removal of DBF Precursors
The following process were identified in the 1998 DBF Technologies &Costs Document as
the most effective technologies for NOM (DBF precursor) removal:
• Coagulation/filtration , particularly at low pH and high coagulant dosages;
• Precipitatrve softening, particularly at high pH;
• GAC adsorption; and
• Membrane processes.
' i
The 1998 DBF Technologies &Costs Document provides cost for the following NOM removal
processes: , ' .
• Enhanced coagulation to improve NOM removal (only for coagulation/filtration
systems);
• Enhanced pretipitative softening to improve NOM removal;
• . Installing post-filter GAC adsorption; and
• Installing membrane filtration (retrofit to the base plant).
Chapter 3.0 of this document provides a more detailed description of the applications and limitations
for the proceeding devices for DBF control. Composite costs have been developed for each
technology listed above and are reported in Chapter 4.0 of this document.
2.2.2 List of Alternative Disinfection Schemes for DBF Control
The 1998 DBF Technologies ft Costs Document provides background information and unh costs for
meeting the established MCLs under the Stage 1 DBPR for the following alternate disinfection
processes: ' ' .
• - Moving the poitt of chtorination;
• Using monochloramine (as opposed to free chlorine) as a secondary disinfectant;
• Using ozone as a primary disinfectant and monochloramine as a secondary
•disinfectant; and
• Using .chlorine dioxide .as a primary disinfectant and chlorine as a secondary
Each of these disinfection schemes is evaluated based upon applicability and affordability to small
systems in chapters 3,4, and 5. '
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2.2.3 List of DBF Removal Technologies
The effectiveness of technologies for DBF removal (post formation) is limited by the
following factors
• The amount of DBFs formed in the treatment plant relative to the amount formed in
the distribution system; and
• Costs for required equipment.
2.2.3.1 Point-of-Entry (POE)/ Point-of-Use (POU) Removal, of DBPs
Point-of-Use (POU) devices, for which unit costs were developed in the Technologies and
Costs Document for Point-of-Entry and Point-of-Use Devices for Control of Disinfection By-
products (US EPA. I998d) can be an affordable alternative for the removal of DBPs after formation
for small systems because they effectively remove DBPs and are cost effective. Although the US
EPA believes POU devices to be affordable (see chapters 3 and 4 of this document), the Agency has
reservations listing POU devices as a compliance technology for small systems. The reservations
stem from the belief that POU devices do not address all routes of exposure (e.g., volatilization and
dermal exposure from DBPs). Because of these concerns, the US EPA believes additional research
is needed prior to listing POU devices as a compliance technology for small systems. The
determination to not list POU devices for DBPs is consistent with the findings in the Small System
Compliance Technology Lists included in the Federal Register on August 6,1998 (63 FR 4203), in
which POU devices were not listed for VOCs. When additional information is available, the US EPA
may consider listing POU devices as a compliance technology for small systems.. POE devices are
not considered affordable (see chapter 3 and 4) treatment alternatives. Further, POE devices are still
considered emerging technologies because of waste disposal and cost considerations and therefore
are not considered compliance technologies at this time for small systems. The POE/POU devices
examined include the following:
• Reverse osmosis (RO); and
• Granular activated carbon (GAG).
POE/POU devices are evaluated in chapters 3 and 4.
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3.0 COMPLIANCE TECHNOLOGY DESCRIPTIONS
This .chapter provides descriptions of the technologies listed in Chapter 2. Specifically, it
descnbes operational characteristics and performance capabilities of technologies for the control of
DBFs The information presented in this chapter was obtained .from supporting references.
3.1 Compliance Descriptions for Precursor Removal Technologies
NOM is ubiquitous in surface and ground water sources. NOM consists of humic substances,
amino acids, sugars, aliphatic acids, aromatic acids and a large number of other organic molecules.
Removal of NOM prior to disinfection not only reduces DBF formation, but also can reduce the
disinfectant dosage level required to maintain an adequate residual in the distribution system and limit
microorganism regrowth. The processes examined for their ability to remove NOM include the
following:
• Precipitation / filtration processes such as coagulation and softening;
• Adsorption processes such as granular activated carbon (GAC),
• Oxidation processes such as ozone and chlorine dioxide; and
• • Other processes such as membrane technology.
3.1.1 Enhanced Coagulation
Coagulation is a treatment process in which the surface charge properties of solids are
changed to allow agglomeration and/or to enmesh particles into a flocculated precipitant. The
agglomerated particles, or floe, than settle under the influence of gravity or are removed through
filtration. Enhanced coagulation can be achieved by decreasing coagulation pH levels and increasing
the dose of alum or ferric coagulants. Enhanced coagulation renders some dissolved species (e.g.,
NOM. inorganics, and hydrophobic SOCs) insoluble and the metal hydroxide particles produced by
the addition of metal salt coagulant* .(typically aluminum suttate and ferric chloride or ferric suifate)
can adsorb other dissolved species. The use of coagulants with low-pressure membrane processes
such as microfihration and uhrafikran'on can result in a slightly improved NOM removal in addition.
to significant paniculate removal , .
Enhanced coagulation processes remove NOM from drinking water sources by several
mechanisms (Dempsey, et a)., 1984; Smsabaugh. et al., 1986; Randtke, 1988). The removal of NOM
by enhanced coagulation can be generalized into the following two basic steps at a macroscopic level:
• Convert some NOM from the dissolved phase to the paniculate phase during
• • coagulation and fiocculation stages.
• Remove particulates, including those containing NOM, during clarification and
filtration stages.
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ei ai 11°95) found that coagulation preferentially removes higher molecular \veight
compounds over-lower MW compounds Dryfuse et al (1995) showed increased coagulant dpses
led to near complete removal of the large (>3K) fraction and over 50 percent removal of the
intermediate (0 5 - 3K) fraction. This suggests that enhanced coagulation processes may remove a
greater percentage of NOM when used for treatment of waters containing higher percentages of large
NOM molecules.
s
Many other factors have been found to also effect NOM.removal. Sinsabaugh, et al. (1986),
found molecular charge distribution to be second only to molecular weight distribution as a factor
influencing NOM removal. Sinsabaugh et al., (1986) also found solubility distribution, to be
important. Dryfuse et al., (1995) found the hydrophobic fraction to be readily removed at
conventional doses, and at increased doses, a 20 to 60 percent removal was achieved of the
hydrophilic fraction. Knocke, et al. (1986) conducted a study examining the effects of temperature
on NOM removal. The study was conducted with alum and ferric sulfate at temperatures of 2 and
22°C. The authors concluded that even though turbidity removal was impaired at low temperatures,
there was no effect on the removal of TOC or THMFP. Further, the humic. fraction of NOM has
typically been found to be more instrumental in DBF formation than the non-humic fraction. Specific
ultraviolet light absorbance (SUVA) has been found to be a good indicator of the humic content of
a water (Edzwald and Van Benschoten, 1990).
Several bench-scale studies have been conducted to examine the impact of coagulant dose and
coagulation pH on NOM removal (Kavanaugh, 1978; Young and Singer, 1979; Semmens and Field,
1980; Chadik and Amy, 1983; Knocfce, et al., 1986; Hubel and Edzwald, 1987; James M.
Montgomery, 1992). These studies have generally demonstrated that the removal of NOM can be
optimized by maintaining certain pH ranges during coagulation, floccuiation and sedimentation. For
alum coagulation, the optimal pH for NOM removal generally occurs in the range of pH 5 to pH 6.
The optimal pH for ferric coagulation generally occurs in the range of pH 4 topHS.
Some studies have demonstrated that preojtidation enhances NOM removal by alum enhanced
coagulation; however, because of the reduction in NOM molecular size, preoxidation could inhibit
NOM removal. A Preoxidation strategy is not generally recommended for NOM removal
James M. Montgomery (1992) conducted a study with AWWA on eighteen raw water
samples from utilities. From this study, James M Montgomery concluded that modified coagulation
may be applicable for the minimization of DBFs in finished water depending on water quality and
MCL values set by the US-EPA. v
In summary, enhanced coagulation can achieve significant levels ofNOM removal. The actual
removal is greath/ dependent on source water, constituents, and treatment characteristics (e.g. ahim
dosage, pH and TOC levels). Higher NOM removal can be achieved by decreasing coagulation pH
levels and increasing the dose of ahim and ferric coagulants. To ensure proper operation, a stalled
operator and higher monitoring is required. Enhanced coagulation is considered a compliance
technology for all size systems, and is listed as Best Available Technology (BAT) for organic DBFs
in the-DBPR.
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3.1.2 Enhanced Precipitative Softening
Lime softening removes NOM by the same mechanism as coagulants and can remove
significant amounts in some cases(US EPA, 1998c). in contrast to coagulants, CaC03 solids have
a small surface area and a negative charge. However, because calcium has an affinity for certain
functional groups (mainly carboxylic acids), some NOM removal will be possible. Significant NOM
removal can be achieved when MgOH is precipitated with high pH. The degree of NOM removal
by precipitative softening depends on a number of factors including the following:
• Nature and concentration of NOM entering the process.
• Other water quality characteristics including calcium and magnesium hardness. .
• Treatment processes, such as oxidation, used prior to precipitative softening.
• . Type and dose of the chemical being used for hardness removal.
Physicochemical characteristics of the NOM will also affect the ability of softening to remove
adsorbable organics including the following: charge, molecular weight, functionality, solubility,
degree of polymerization and molecular geometry.
Several studies have been conducted to examine the impact of molecular weight on the
precipitative process (Semmens and Staples, 1986; El-Rehaili and Weber, 1987; Liao and Randtke,
198S). The studies found that most of the removable NOM was the high molecular weight fraction.
In one study, larger molecules, in particular those with molecular weight greater than 10,000, were
readily removed by precipitative softening. In another study, an increase in TOC was observed for
the fraction containing molecules with molecular weights less than 1,000. They also found that
polymers of organic substances were more likely to be removed than their monomeric analogs.
Charge also plays a major role in the effectiveness of the precipitative softening process.
CaCOj precipitates are negatively charged. Since most NOM is negatively charged, adsorption will
not occur unless sufficient chemical interaction is available to overcome the charge repulsion.
Further, solubility plays an important role in the effectiveness of the precipitative process.
Liao and Randtke (1985) found that if a compound is top hydrophilic or too hydrophobic it will not
be readily removed. Sfimrnem and Staples (1986) found that hydrophobic molecules were more
readily removed than hydrophflic molecules,
Other factors include the type* of functional group on the compound. Calcium will
preferentially bond with oxygen-containing species (Liao and Randtke, 1985). Additional, alteration
of the functional groups upon disinfection may aid in the NOM- removal process (e.g. ozonation prior
to lime softening). In addition, when the ratio of raw water magnesium to total calcium was
increased, the removal of NOM was also increased (Randtke, et al., 1982; Liao and Randtke, 1985).
The results of the study also suggest that magnesium hydroxide adsorbs NOM to a stronger degree
than calcium carbonate and NOM removal was enhanced by the formation of finery divided calcium
carbonate with poor crystallinrty. Liao and Randtke (1985) suggests the following two-stage process
be used to effectively remove both NOM and hardness:
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S;age 1 Optimize NOM removal by adding excess lime to elevate pH and
calcium levels.
Stage 2 Optimize hardness removal by adding carbonate alkalinity and by
recycling sludge
In summary, precipitative processes can achieve the same range of TOC removal as achieved
by alum coagulation/filtration processes. Further like enhanced coagulation, the precipitative
softening process can be modified to increase NOM removal. Many studies suggest DBPFP removals
ranging from 30 to 60 percent can be achieved under certain conditions(US EPA, 1988, Stevens, et
al., 1989). In general, NOM removal is enhanced by conditions that favor the formation of
magnesium hydroxide and small calcium carbonate particles. These conditions are achieved by the
following:
• Elevating pH to approximately 10.8 or higher,
• delaying carbonate addition for several minutes; and
• Delaying sludge recycling.
To achieve proper operation, a skilled operator and higher monitoring is required. Enhance
precipitative softening is considered a compliance technology for all size systems.
3.1.3 Granular Activated Carbon (GAG)
The removal of NOM by GAG adsorption depends on a large number effectors, including
the following:
• » '
Molecular size, polarity and concentration of NOM entering the GAC process;
pH and ionic strength; . .
Treatment processes used prior to the GAC process;
GAC characteristics such as pore size distribution and surface chemistry; and
Operational characteristics such as Empty Bed Contact Tunes (EBCT) and GAC
usage rate.' . . •
Several studies have examined the impact of pH on- the adsorption of NOM and humic
extracts by GAC processes (Weber, et al., 1983; Randtke and Jepsen, 1982; McCreary and Snoeyink,
1980; Summers, 1986). These studies showed an increase in the removal of TOC with decreased pH
levels. These findings were reaffirmed by a pilot-scale study conducted by Malcolm Pirnie (1990)
using a rapid small scale column tests downstream of a continuous flow pilot plant for the City of San
Diego. GAC usage rates of 500 Ibs/MG was observed for pH 7.3 to reach a target THM level of
25Mg/L. The GAC usage rate decreased to 200 Ibs/MG at a pH of 6.5 to achieve the same target
THM level. " ' ,
t
The impacts of coagulation on NOM adsorption have also been weO documented in batch
experiments studying adsorption equilibria (Weber, et al., 1983; Randtke and Jepsen, 1981; Lee, et
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ai :°81 Ei-Rehaili and Weber. 1987. Harrington and DiGiano. 1989) Coagulation processes, as
a pretreatment to GAC. can both reduce influent TOC concentration and decrease the influent pH
to the absorber, thus leading to improved GAC performance. A study conducted by Semmens et al.,
(1986) showed that coagulation pretreatment to GAC increases the run time of the contactor, and
that further improvement in GAC run time can be achieved through higher coagulant doses.
Several studies have examined the relationship between NOM molecular size distribution and
GAC pore size distribution (Summers and Roberts, 1988; Lee et al., 1983; Semmens and Staples,
1986; El-Rehaili and Weber, 1987; Chadik and Amy, 1987). The studies have shown the GAC
process to favor removal of NOM molecules of low to moderate size. This is due to small GAC pores
physically excluding large NOM molecules from adsorbing. Thus, GAC having a greater quantity of
large pores can be expected to remove more NOM than GAC's having a smaller quantity of large
pores.
An important operational parameter to examine is EBCT. Summers et al., (1997a) evaluated
EBCT of 10 and 20 minutes. EBCT was shown to have a definite effect in prolonging the life of a
GAC contactor, however, the carbon usage rate was relatively unaffected by the EBCT evaluated in
this study.
In summary, GAC is an effective process for removal of NOM from drinking water sources.
In general, the process can be modified to provide the same level of NOM removal at lower GAC
usage rates by the following:
• Maintaining low pH conditions through the process;
• Increasing NOM removal in processes that precede GAC 'adsorption, such as
enhanced coagulation; and . .
• Using EBCT's greater than or equal to 10 minutes.
Pretreatment with enhanced coagulation is included in cost estimates. To achieve proper operation,
a skilled operator and higher monitoring is required. GAC treatment for precursor removal is
considered a compliance technology for afl size systems, and GAC is listed as a BAT for control of
organic DBFs in the DBPR.
34.4 Membrane Pn
Membrane processes can remove DBF precursors through the filtration and adsorption of
organics. Overatt shape and chemical characteristics can also effect the permeation of NOM through
a membrane (Buckley and Hurt, 1996). Disinfectant By-product formation potential (DBPFP) is
reduced by the rejection of larger NOM molecules by smaller membrane pores.
DBF precursor removal is greatly depended upon the type of membrane processes, membrane
material characteristics, and water quality characteristics ( i.e. NOM characterization and
concentration, pH). Pressure-driven membrane processes can be categorized as follows:
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rr.icrotiiiration t Nff;. ultrafiltration (LT). nanotlltrauon fNT) and reverse osmosis (RO) NT and RO
are characterized as being an effective DBF precursor removers since they are a high-pressure
processes uith relatively small pore sizes In contrast, UP and MF 'are characterized as not being able
co remove DBF precursors since they are low-pressure processes with larger pore sizes.
NOM removal depends greatly on the characteristics of the membrane, including MWCO
(Molecular Weight Cut-off) and hydrophobicity, characteristics of the NOM, characteristics of pre-
treatment (if applicable), and the membrane system operating parameters. Allgeier and Summers
(1995) evaluated the use of NF to reject NOM and DBF (UFC) precursors for five waters using a
bench-scale system. They found that.TOC-and precursors for TTHM, HAA6 and chloral hydrate
were all rejected by 66 to 97 percent.
MF and UF are not applicable to the removal of Bromide due to there large pore sizes. In
contrast, NF and RO are capable of bromide removal. NF has also demonstrated chloride removals
between 60 and 70 percent, with bromide expected to be nearly identical (Conlon and McClellan,
1989; Taylor et al., 1989 a,b). However, the utilization of NF or RO for the removal of bromide only
would not be cost effective.
The membrane process examined for inclusion in the small system compliance technology list
was NF. Buckley and Hurt, (1996) asserted that NF was gaining considerable popularity as a DBF
removal processes since production costs are comparable with competing processes. This is
especially true given the potential for stricter regulations. ' .
In summary, membranes, particularly those with MWCOs in the 100 to 500 range, appear to
be very effective as a means of DBF precursor removal achieving 70 to 95 percent removal of such
DBF precursor's as TOC, THMFP, and TOXFP. Systems utilizing membranes with higher MWCOs
are likely to achieve higher effluent water quality but at an increased cost. The overall success of
NOM removal by membranes is highly dependent on the type of membrane utilized in treatment and
source water characteristics. Small systems will need to perform pilot testing to account for site-
specificconcMonsandsciireewatffdjaracteristics. This wiD help small systems in the determination
of whether membranes may be applicable to their situation. To achieve proper operation, a skilled
operator and higher momtoring is required: NF treatment for precursor removal is considered a
compliance technology for all size systems. • '
3.2 Compliance Evaluation of Alternate Disinfection Technologies
The objectives of disinfection in water treatment are:
• To achieve inactivation of disease-causing microbes (primary disinfection) whose
presence is ubiquitous in natural surface waters; and
• To maintain conditions in the distribution system which prevent regrowth of such
organisms (secondary or residual disinfection).
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Disinrectants are used as oxidizing agents to inactivate pathogens, but they also react \Mth NOM to
form DBFs The types and quantities of DBFs formed are related to the disinfection strategy
employed, and can be altered by using an alternative disinfection strategy Alternate'disinfection
strategies should
1 • Adequately meet treatment objective's, including meeting regulatory disinfection
requirements, color removal, iron oxidation and taste and odor control;
• Limit the formation of regulated DBFs to concentrations lower than the MCL.
The most prevalent disinfectants used for primary disinfection in the United States include
chlorine, ozone and chlorine dioxide. Secondary disinfection is achieved by maintaining a residual
amount of disinfectant throughout the distribution system. Chemicals typically used for secondary
disinfection include chlorine and chloramine.
3.2.1 Moving the Point of Chloruution
After the promulgation of the THM Rule in 1979, many utilities were able to meet the THM
standard of 0.10 mg/L by moving the point of chlorination, reducing the chlorine dose, and/or
eliminating prechlorinatioh.
* i
, Summers (1997b) conducted a bench-scale test examining the impact on TOX, TTHM, and
HAAS formation from moving the point .of chlorination. The study involved 16 waters representing
a wide range of water qualities. Chlorine was added to four parallel jars at different tunes to simulate
chlorination during coagulation, flocculation and sedimentation. The process decreased DBF
formation and the chlorine demand by providing additional time for the NOM removal before chlorine
could react with NOM to form DBFs.
3.2.2 Chloramines as ft Secondary Disinfectant
Numerous studies have demonstrated that chloramines produce much lower levels of DBFs
than does free chlorine (AWWARF 1993 and Svmons 1996). The byproducts formed by
chloramination, for the most part, are identical to those produced during chlorination and include
THMs, HAAs, haloacetonitriles, and cyanogen chloride. The formation of DBFs resulting from
chloramination is influenced by the following treatment variables (AWWARF 1993):
Point of ammonia application;
Chloramine dosage; .
pH;
Temperature;
Chlorine:ammonia-nitrogen ratio; and
Mixing and reaction time for chloramine formation.
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TTHM ie\e:s remain quite low at chlorine to ammonia weight ratios less than 5 1. then increase
dramaticallv above the 5 1 ratio (AWWARF 1993) The tvpical utility ration for chlorine to ammonia
is 5 1 to 5 1 Good mixing can also reduce DBF formation by reducing the time free chlorine can
react with NOM. The reaction of chlorine and ammonia, assuming complete mixing, can take from
0 07 to 3 seconds at neutral pHs of 7 to 9 and temperatures of 20 to 25 °C. According to Symons
(1996), DBF formation decreases with an increasing pH.
The 1998 DBF Technologies & Costs Document provides information from multiple case
studies that examine the impact on DBF levels after switching to chloramines as a secondary
disinfectant. This information was presented in a publication by the American Water Works
Association Research Foundation (AWWARF, 1993). In many cases, the addition of chloramines
has proven to be a successful strategy for achieving DBF levels well within regulatory compliance.
\
There is little evidence that .suggests the wide spread use of chloramines by small systems.
This may be due to the high monitoring requirements and extended contact times necessary to ensure
adequate operation. Chloramine disinfection requires careful monitoring of the ratio of added
chlorine and ammonia. Chloramines also possess less potency than other disinfectants and thus
requires longer contact time. Chloramination is listed as a compliance technology for all size
categories of public water systems.
3.2.3 donation as a Primary Disinfectant
f
Ozone is an extremely strong oxtdant that reacts with organic and inorganic material in natural
water. For waters containing bromide, ozonation leads to the formation of hypobromous (HOBr),
hypobromite (Obr~), bromate, and brominated organic by-products^ The principle organic DBFs
identified are bromofbrm, dibromoacetonitrile, dibromoacetic acid, cyanogen bromide, bromopicrin,
1.1 -dibromoacetone, other bromoacetic acids, and bromohydrins (Cooper et ai., 1986, Weinberg et
al, 1993, and Cavanagh et al, 1992).
The formation of ozonation by-products is dependent upon numerous, water quality
parameters, including bromide ton concentration, the source and concentration of NOM, pH, ozone
dosage, temperature and alkalinity. Krasner et al (1993) noted that as the pH of ozonation was
lowered, the ozone dosage necessary to meet the contact time (CT) requirements of the SWTR
dropped and less bromate was formed. .For one of the waters evaluated during bromide spiking,
bromate concentrations were reduced from 24-68 ^g/L at pH 8 to <5-7 /*g/L at pH 6.
Ozone dosage also plays a critical rote in the formation of ozonation by-products. The ozone
dosage selected will depend upon specific site characteristics. For systems utilizing ozone as a
primary disinfectant, an ozone residual is required to meet the CT requirements of the SWTR. To
meet the CT requirements of the SWTR, Song et al (1995), demonstrated that lower ozone dosages
and longer contact times should produce less bromate than higher dosages at shorter contact times.
The 1998 DBF Technologies &Costs Document provides information from multiple case
studies that examine the impact on DBF levels after switching to ozonation as a primary disinfectant.
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In one case, the replacement of pre-chlonnation \vith pre-ozonauon' resulted in decreased
concentrations of chloroform, bromodichloromethane. dichJoroacetic acid and trichloroacetic acid
Increases in the concentrations of bromoform, dibromoacetic acid, 1,1-dichioropropanone.
dibromoacetonitrile and chloropicrin were also observeo, however these concentrations occurred* at
concentrations near l/zg/L (Metropolitan and Montgomery, 1989; and Jacangelo, et al., 1989). An
ozone/chloramines disinfection strategy produces much lower DBF concentrations than most
chlorine/chlorine or chlorine/chloramine strategies. Because ozone oxidizes some of the NOM to
biodegradable organic matter, biologically active filters may be required to reduce the potential for
biogrowth in the distribution system.
The operation of an ozonation treatment technology requires a high level of monitoring and
operator skill. Ozonatibn is listed as a compliance technology for all size categories of public water
systems. ••
3.2.4 Chlorine Dioxide as a Primary Disinfectant
Use of chlorine dioxide does not result in the generation of brominated by-products or
meaningful levels of organic byproducts. However, chlorate ion and chlorite ion formation are the
main by-products of chlorine dioxide use. The MCL for chlorite under the Stage 1 DBPR is 1.0
mg/L. Hoehh et al., 1996, suggests that chlorate ion by-product comes from three principle sources,
the most significant of which is the oxidation of chlorine dioxide by excess chlorine during generation
or by oxidant addition to the chlorine dioxide treated water. Chlorate and chlorite ion production can
be prevented to a significant extent through careful feedstock handling procedures and by frequent
generator tuning and monitoring to avoid excess chlorine use. Further actions that can prevent
chlorate formation involve the avoidance of mixing chlorine dioxide with other oxidants (e.g., ozone
or chlorine) and protecting chlorine dioxide from light. Chlorite removal can be achieved with - the
addition of reduced iron and sulfite ions (Le. Fe coagulants).
Chlorine dioxide requires a higher level of operation and maintgn^neg including monitoring
as compared to other DBF control strategies. It further requires a highly trained staff to ensure
proper operation. Also, there remains concern as to the ability of chlorine dioxide to provide residual
disinfection protection in .the distribution system. It is currently assumed that chlorine dioxide does
not provide a residual in the distribution system. The 1998 DBF Technologies & Costs Document
does provide multiple case studies for larger systems but little evidence suggests the operation of
chlorine dioxide, system at small facilities. However, chlorine dioxide units may be available for
smaller systems from treatment vendors. Chlorine dioxide is listed as a compliance technology for
all system sizes.
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3.3 Compliance Evaluation of Disinfection By-Products Removal and Control of
Disinfectant Residuals
3.3.1 Compliance Technology Evaluation of POE/POU Devices
Although the US EPA believes POU devices to be affordable (see chapters 3 and 4 of this
document), the Agency has reservations listing POU devices as a compliance technology for small
systems. The reservations stem from the belief that POU devices do not address all routes of
exposure (e.g., volatilization and dermal exposure from DBPs). Because of these concerns, the US
EPA believes additional research is needed prior to listing POU devices as a compliance technology
for small systems. The determination to not list POU devices for DBPs is consistent with the findings
in the Small System Compliance Technology Lists included in the Federal Register on August 6,1998
(63 FR 4203), in which POU devices were not listed for VOCs POE devices are still considered
emerging technologies because of waste disposal and cost considerations and therefore are not
considered compliance technologies at this time for small systems.
•However, this section provides information regarding, the operation and maintenance of
POE/POU devices. To be effective, water treatment authorities must implement the appropriate
technology, and ensure proper maintenance of the units. Water quality monitoring is imperative to
ensure all devices are operating efficiently and effectively.. Information and assumptions for this
analysis are based in part on Cost Evaluation of Small Systems Compliance Options Point-qf-Use
and Potnt-of-Entry Units. (US EPA, 1998a) and the Technologies and Cost Document for Point-of-
Entry and Point-of-Use Devices far the Control of Disinfection By-products (US EPA, I998d),
among other sources.
Point-of-Entry Devices
Point-of-Entry (POE) devices provide treatment for aQ the water entering a dwelling or .house.
POE device^ cc«ipare4 to POXJdevk;es,piovkfe
risks and.exposure to e«niMUMnt« (j.e. volatile organic compounds) via inhalation and dermal
contact. Thus. POE devices are more applicable in situations where contaminants may cause heahh
effects through non-ingeation pathways because all the water entering the dweUmg receives treatment.
Water test information is •needed in all POE applications to ensure proper application of the
technology (Johnson, 1996). Monitoring and service of POE units is critical to ensure proper
performance. Flow .meters and seasonal monitoring are essential components of the overall
maintenance scheme to gather information regarding water use and its effects on the POE system.
This attention, especially during the first year of service, can result in a lower overall cost of
maintenance to the water treatment authority (Johnson, 1996).
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3.3.1.2 Point-of-l'se Devices
Pomt-of-Use (POL') devices are utilized for treatment of water meant only" for consumption
They are usually attached to household faucets. There are several different device alternatives
including: faucet-mounted units, counter-top units, in-line and line bypass units. Counter-top units
are not considered a compliance technology since their mode of operation creates a high potential for
bacterial contamination. Further, faucet-mounted units may not prove applicable as a compliance
technology due to a relatively short contact time. Therefore, this document examines and develops
cost for in-line and line bypass POU devices as the only viable alternatives for meeting the DBP Stage
1 MCLs. POU devices may require high levels of monitoring, verification, and awareness of the
various reactants produced to maximize disinfectant qualities while minimizing the production of odor
from breakpoint and nitrogen trichloride production (Harrington, 1996).
\
The cost estimates presented in this document meet the following requirements outlined in
the Safe Water Drinking Act (SWDA), Section 1412 (bX4XEXii):
• POE/POU treatment units shall be owned, controlled, and maintained by the public
water system or by a person under contract with the public water system; and
• No POE/POU unit may be included on the list of affordable technologies, treatment
technique, and other means of compliance with an MCL or treatment technique unless
it is equipped with mechanical warnings to ensure that customers are automatically
notified of operational problems; and
• The use of POE/POU devices to achieve compliance with a MCL for a microbial
contaminant (or an indicator of a microbial contaminant) is strictly prohibited.
The SDWA also requires POE/POU units be independently certified as having met applicable
American National Standards Institute (ANSI) standards prior to being accepted for compliance with
a MCL or treatment technique requirement. In listing any technology, treatment technique, or other
means'pursuant to this clause, the US EPA is required to consider the quality of source water to be
treated. The following standards have been established by ANSI/NSF for POE/POU units examined
in this document: .
I. ANSI/NSF 42 - Aesthetic effects; '
2. ANSI/NSF 53-Heahh effects;
3. ANSI/NSF 55 - Ultraviolet microbiological treatment
4. ANSI/NSF 58 - Reverse Osmosis Treatment systems; and
Other organization have adopted standards for POE/POU units. The Water Quality Association
(WQA) standards for household and commercial water niters include water filters (S-200-73), and
RO systems (S-300-84). Standard test to examine the operational parameters of RO (D4194-82) and
GAC(D3922-80) units have been developed by The American Society for Testing and Materials
(ASTM). The analysis presented in this document assumes that water treatment authorities will only
select devices certified under NSF Standards and other applicable technology standards.
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3.3.2 POE/POU Reverse Osmosis Devices
Reverse Osmosis involves forcing the contaminated source water through a semi-permeable
membrane By maintaining a pressure gradient greater than the osmotic pressure of the feed,
contaminants are rejected by the membrane and discharged in a reject stream. Periodic flushing of
the reject water is still required to reduce the potential for scale formation on the membrane.
Depending upon the source water quality, pre-treatment may be required to reduce harm to the
membrane due to disinfectant residuals such as chlorine.
Slovak and Hafher (1996) detail six important water-quality parameters to review in an effort
to ensure satisfactory system performance.
1. Total Dissolved Solids (TDS). The level of IDS in feed water should be examined
before choosing the type of membrane to be utilized, since the rejection rate varies
with each membrane. TDS can cause osmotic "back pressure," which can reduce the
effective feed water pressure. ...
2. Feedwater pressure. The net pressure (net pressure = feed pressure - back pressure -
osmotic pressure) is directly proportional to the RO production rate and effects the
percent rejection of TDS. For cellulose POU membranes, the minimum.net pressure.
should be 25 psi. For thin-film, (TF) membranes the recommended minimum net
pressure is 15 psi.
3. Feedwater temperature.' Temperature can effect the viscosity of water and thus the
RO production rate. For die determination of a production rate, the industry standard
recommends 77° F (25° C). The determination of temperature is crucial to ensure
membrane degradation does not occur. The mawtmim operating temperature for
. cellulose acetate (CA) and cellulose triacetate (CTA) membranes is 85° F (29° C),
and for TF membranes, 100° F (38° C).
4. Feedwater pH. AtpHle :is exceeding 8.0, cettulosic membranes (CA, CTA and
CA/CTA blends) can lose :neir rejection of TDS because of deterioration due to
hydrolysis, TF membranes can safely operate at pH levels up to 11.0.
5. Water disinfection. Disinfectants such as chlorine, chloramines or ozone can cause
membraiK deterioration. X>fluk»e membranes resist the effects of chlorine and other
chemical oxktizera but can be deteriorated by certain bacteria in non-disinfected
. supplies. Most TFmemiffanes are rainiine to bacterial deterio
free chlorine *fd other disinfectants well.
6. Imparities. Water analysis is crucial prior to adopting an RO treatment strategy to
ensure no impurities are present (i.e. excessive hardness, manganese, alum ect).
Paul (1994) suggests mat pre-treatment is critical prior to the application of an TF composite
membrane for source water* disinfected by chlorine or chloramines. To reduce chlorine and
chloramines prior to the application of RO, activated carbon (AC) provides the most cost-effective
solution. However, the greatest disadvantage to AC treatment is the possibility for microorganism
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The issue of the nsk surrounding bacterial colonization is examined in detail m Section 4 i i
In the case of chlorine and chlorarmne, cellulose membranes are resistant to their oxidizing pressures
(Harrington. 1996)
i
The operational performance data provided by the OEM demonstrates a greater than 95
percent reduction in TTHMs at an average influent concentration of 200 to
3.3.3 POE/POU Granular Activated Carbon (GAQ Devices
POE/POU GAC devices are widely used and typically the easiest to maintain. Activated
carbon is produced in block, granular or powdered form, although granular activate carbon is the
most common. It is produced by heating carbonaceous substances in the absence of air, resulting in
an absorbent'material that is highly porous (Gordon et. Al., 1997). GAC removes contaminants by
an adsorption process influenced by contaminant solubility and affinity for the carbon surface. Water
conditions, such as temperature and pH, can greatly effect the adsorption capacity of GAC. GAC
is able to improve water conditions through the removal of organic and solvent contaminants,
including volatile organic compounds (VOCs) and trihalomethanes (THM), along with many other
organic chemicals (Gordon, et al., 1997). GAC effectively removes chlorine improving water taste
and reducing odor. Being an effective remover of chlorine, GAC is a common pretreatnient option
in the case of TF membranes, see Section 3.1.3. The removal of chlorine does pose some concern
' surrounding the issue of bacterial growth. GAC filters need to be replaced frequently to prevent
breakthrough and prevent bacteria colonization.
Bell et al (1984), in a study of home water treatment systems, reported a significant increase
in test-unit effluent heterotrophic-plate-count (HPC) densities compared to influent HPC levels after
overnight and 2-day stagnation periods. Additionally, Reasoner et al (1987) found'high levels of HPC
bacteria • in GAC effluent water in laboratory tap water.. This suggests that GAC filters are
susceptible to colonization by heterotrophic bacteria. Further, Snyder et al. (1.99S) noted that these
high HPC densities may prevent pathogenic bacteria colonization of the GAC finer beds. It is to be
note no increase in illness incident was connected to the exposure described in these studies. It is
recommended that consumers run water for 30 seconds prior to use to allow the removal of bacteria
easily washed off the filter media. POU contamination from bacteria is not considered significant due
to the frequency of filter replacement outlined in section 2.1.3.1. Further, bacterial growth in POU
systems can be controlled through proper sizing of the unit to household needs to prevent long tank
holding times of post-treatment water. * If stagnation does occur (I** after a vacation), proper -
flushing of the system should reduce the potential levels of bacterial contamination (Schlafer, et al.,
1997).
\
Potential bacterial contamination can also occur due to backflow (Cheesebrow, 199S). All
POU units used for the basis of cost estimation include a air gap faucet to protect against potential
backwash contamination. For POE devices utilizing GAC, the cost of a ultraviolet unit module has
been added to capital for post treatment mediation of bacteria.
Page -23-
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The operational performance data provided b,y the OEM demonstrates a 95 percent reduction
in TTHMs at an average influent concentration of 300 Mg/L. However, if DBF concentrations are
^ery high, the water treatment system may wish to crnsider the application of POE/POU reverse
osmosis instead of POE/POU GAC.
Page -24-
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4.0 BASIS FOR COMPOSITE COST ESTIMATES
4.1 Introduction
One consideration in the completion of this guidance small system technology listing
document was the development of a composite cost estimates for the size categories outlined in the
1996 SDWA The size categories are as follows:
• 10,000 or fewer but more than 3,301;
• 3,300 or fewer but more than 501; and
• 500 or fewer but more than 25.
The composite cost presented in this chapter are based on the cost reported in the 1998 DBF
Technologies &Cost Document for the control of disinfection by-products and the 1998 Technologies
& Cost Document for POE/POU Devices. The 1998 DBF Technologies & Cost Document costs
include solids dewatering lagoons and dewatered solids handling as the waste disposal option for each
technology. Composite cost development is required since the cost developed in the previous
document do not directly correspond to the population size categories as outlined in the 1996 SDWA.
The estimated treatment costs developed in the 1998 Technologies and Costs Document for the
control of disinfection by-products were based on the standard EPA 12 flow categories. The
population served, average flow and design capacity for each small system flow capacity is presented
in Table 4-1.
Table 4-1
US EPA Flow Categories (early 1990s)
Rmr
100
37
0.0056
0.024
101
500
225
0.024
0.087
501
1,000
750
0.086
0.27
1,001
3,300
1,910
0.23
0.65
3,301
10.000
5.500
0.70
1.8
In order to derive composite capital and O&M costs for the three size categories under the
SDWA, design and average flows are needed for a typical system within each size category. In the
document, Variance Technology Findings for Contaminants Regulated Before 1996 (US EPA.
1998J), a weighted average of the flows reported in Table 4-1 was derived for each of the first two
SDWA small system categories. The design and average flows used to derive costs are reported in
Page-25-
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Table J-2 Cost curves were generated for the cost estimates reported in the 1998 Technologies and
Costs Document with design and average flow as the independent parameter for capital and O&M.
respectively
Table 4-2
Flow Categories Used for the Development of Composite Costs
SBWASbe
23
500
0.01S
0.058
501
3.300
0.170
0.500
3.301
10.000
0.700
1.8
The cost developed for POE and POU devices in the 1998 Technologies and Costs Document for
POE and POU Devices for the Control of Disinfection By-products, were based on a range of
households. Cost curves were generated for both capital and O&M cost estimates with number of
households as the independent parameter. The subset of data from the Community Water Supply
Survey (US EPA, 1997a,b,c) that was used to develop the baseline for current waters bills in chapter
5 of this document 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 categories. The POE/POU composite
costs were derived using the number of households in Table 4-3.
Tabte4-3
Number of Households by Size Category for POU/POE Options
1
2
3
25
501
3.301
500
3.300
10.000
50
425
1935
Source: US EPA 1998f
All composite costs were escalated for this analysis to 1998 dollars using the Engineering News
Record Building Cost Index and the Bureau of Labor Statistics Chemical and ABied Products Index.
Table 4-4 through Table 4-6 lists the composite cost by technology for the control of DBPs.
Page -26-
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Table 4-4
Composite Cost for Technologies
Examined for Removal of DBF Precursors
ssz
F^^n^VPV-
• .'. 's . .'"
Estimated UDI
25
501
3,301
500
3,300
10,000
•TrttmotMl ITiMBMti*
25
501
3.301
500
3.300
10,000
C«MGM(
.. wu. .-
oawcwt
• MtaA
T«ttlCto«$nfr
*«*•)
trade Coats for Enhanced Coagulation
0.002
0.009
0.08
Costs for Enhant
0.002
0.012
0.10
10
10
6
14
12
9
12
12
8
16
14
11
Estimated Upgrade COM for GAC AdwrptioB (10 minute EBCT)
25
501
3,301
500
3,300
10,000
0.17
0.45
0.96
21
9
14
319
78
50
Estimated Upgrade Costs for GAC Adiorptkn (20 minute EBCT)
25
501
3.301
500
3,300
10,000
0.34
.0.95
2.52
205
102
85
789
248
178
Estimated Upgrade Costs for Nanoflltratioii
25
501
3,301»
3.301"
500
3,300
10.000
10.000
0.12
0.98
2.42
3.22
174
133
85
85
374
282
• 175
204
* Based on the costs reported for Nanofihraiion® 20° C
** Based on the costs reported for Nauofiltrarion @ 10° C
Page -27-
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Table 4-5
Composite Cost for Alternative
Disinfectants Schemes for DBF Control
sa
iSS^
.; °sjf ;
.... . ,,..
<»£*«
- >-. <*••*•) .-
WSSIm
•••• ^**pi)
Estimated Upgrade Costs for Chloramines as a Secondary Disinfectant
25
SOI
3,301
500
3,300
10.000
Estimated Unarade Co
™™
25
SOI
3,301
500
3,300
10,000
0.012
0.016
0.04
its for Ozone as
0.23
0.3S
0.90
8.9
1.2
1.4
29.7
3.6
3.0
Primary Disinfectant (Log 1)
61
S
2
462
S9
35
Estimated Upgrade Costs tor Ozone as Primary Disinfectant (Log 3)
25
SOI
3,301
500
3,300
10,000
0.26
O.SS
1.S
Estimated Upgrade Costs for Onae as
25
SOI
3401
500
3400
'10,000
OJ8
0.67
1.41
122
11
4
S70
94
60
Primary Disinfectant (Log 5)
244
22
6
720
124
58
Estimated Upgrade Com for Chlorine Dioxide as Primary Disinfectant -
fttamud(Logl)
25
SOI
3401
500
3,300 .
10,000
0.1
6.1
0.1
734
67
18
908
82
22
Page -28-
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Table 4-5 (cont)
Composite Cost for Alternative
Disinfectants Schemes for DBF Control
S±£
f *
CfeftttfCo*
(MS)
OftUCMt
W**>
•"httCMtg?*
<«*•*
Estimated Upgrade Costs for Chlorine Dioxide as Primary Disinfectant
- Manual (Log 3)
25
301
3.301
500
3,300
10,000
0.1
0.1
0.1
743
70
. 20
Estimated Upgrade Costs for Chlorine Dioxide as Primar
Manual (Log 5)
25
501
3,301
Estimated
25
501
3,301
500
3,300
10,000
0.15
0.25
0.50
743
70
20
Upgrade Costs for Chlorine Dioxide as Primar
Auto
(Log!)
500
3,300
10.000
0.33
0.33
0.33
593
54
15
916
85
24
v niunffMtnnf .
1,000
109
39
ylMrinfiMtm* .
1162
105
28
Estimated Upgrade Com for Chlorine Dioxide as Primary Disinfectant -
Ann
(Log 3)
25
501
3,301
500
3,300
10,000
0.33
0.33
6.33
597
57
17
Estimated Upgrade Costs for Chlorine Dioxide as Primar
AMD
(Log 5)
25
501
3.301
500
3,300
10,000
0.39
0.52
0.75
599
57
17
1168
108
30
v ftfaififettaiit -
1276
133
45
Page -29-
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Table 4-6
Composite Cost for
DBF Removal Technologies
Poputedoit
5=
Capital CM
(MS)
QAM CM
. <«*««*
T«MOM&7H
<«kpl>
POE Reverse Osmosis (Ground Water)
25
25
500
0.46
. 974
POE Reverse Osmosis (Surface Water)
500
0.46
980
2559
2564
POE GAC (Ground Water)
25
500
0.12
440
859
POE GAC (Surface Water)
25
500
012
445
864
POU Reverse Osmosis (Ground Water)
25
501
3.301
500
3,300
10,000
0.02
0.17
0.78
299
242
226
372
309
290
POU Reverse Osmosis (Surface Water)
25
501
3.301
500
3.300
10,000
0.02
0.17
0.78
308
243
226
• 382
311
290
POU GAC (Grand Water)
25
501
3,301
300
3,300
10,000'
0.01
0.09
0.39
296
242
226
333
275
2S8
POU GAC (Surface Water)
23
501
3.301
300
. 3.300
10.000
0.01
0.09
0.39 .
306
243
226
342
276
238
Page -30-
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5.0 NATIONAL-LEVEL AFFORDABILITY DETERMINATION
/
5.1 Introduction
Section 1412(b)(l5)(C) of the SDWA requires the US 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. The composite costs detailed in chapter 4.0. of this document
were compared to the affordability criteria set forth in the National-Level Affordability Criteria
Under the 1996 Amendments to the Safe Drinking Water Act, (US EPA, 1998b). Although the
SDWA does not specifically address the ability of a system to afford compliance technologies for
existing regulations, the US EPA's interpretation of the statue is that affordability is a key criterion
for evaluating technologies for both exiting and future regulations.
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" under the nation-level affordability
criteria, one option for that system would be to apply to the State for an exemption. New exemptions
will only be available for regulations issued or revised after August 6, 1998. For the regulations
covered in this guidance, new exemptions will not be available. The most recent pre-1996 set of
regulations was the Phase V regulation package. The Phase V rule package was promulgated on July
17,1992. The effective date of the MCLs was January 17,1994. The exemption period is limited
to three years after the Section 1412 compliance date of the MCLs. Thus, a new exemption could
not be issued after January 17,1997 for any regulation in the Phase V package. 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 mat a small system can have no more
than 9 years after the Section 1412 compliance date to meet the appficable MCI/treatment technique .
even if the exemption was issued prior to the 1996 SDWA At
5.2 Role of National-UvelArTortUbaity Criteria
The primary role of the national-level affordability 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 under the Stage 1 DBP Rule, 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 in "Small System Compliance Technology List for the Non-Microbial
Contaminants" (US 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
Page -31-
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identified in Table'5-7a-b and 8
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:
• install a technology to comply with the NPDWR;
• receive an exemption and then install a technology to comply with the NPDWR; or
• obtain a small system variance (if option is available).
The compliance technology list is intended as guidance to provide small systems with information
concerning the types of technologies that can be used to comply with the NPDWR.
5.3 Unit of Measure for the National-Level Affordability Criteria -
Community water systems (CWS) can absorb water service cost increases by directly charging
their customers in the form of increased water bills. 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" (US EPA,
1998b).
Since the household was selected as the surrogate for affordability for CWSs, treatment costs
must be compared with the impacts on households. To make this comparison, there must be a
consistent unit of measure for both parameters. The selected approach was to measure user burden
as the increase to annual household water bills that would result from installation of treatment. To
determine if there are any affordable compliance technologies under the Stage 1 DBP Rule, the
national-level affbrdabifity criteria are compared against the cost ftsrhnates for the applicable
treatment technologies. If there are no affordable compliance technologies,' then variance
technologies would become an option. Since the household was determined to be more vulnerable
to treatment cost increases than the various categories of •non-community water systems, national-
level affordabffity based on households would serve as an adequate surrogate for Non-Transient Non-
Community Water Systems (NTNCWs) as well as CWSs.
After selecting the .impacts on households as the measure for comparing national-level
affordability and treatment costs, a consistent set of units was needed to make the comparison. The
treatment cost models produce rate increases measured in dollars/thousand gallons (S/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 estimates were multiplied by
\
Page-32-
-------
I 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 needed to be adjusted to cover this lost water by increasing the household
consumption Multiplying the rate increase by the adjus- 'd annual household consumption yields the
increase to annual household water bills ($/household/year increase).
The annual water consumption rates derived from the CWS Survey data are contained in
Table 5-1. 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 and was
extrapolated to all system size categories. The baseline for annual household water consumption was
derived directly from data in the 199S Community Water System (CWS) Survey.
Table 5-1
Residential Consumption at Small Water Systems
5.4 Derivation of the National-Level Affordabflhy Criteria
A summary of the methodology used to determine the national-level affordabilhy criteria is
described bdow. Treatment technology costs are presumed affordable to the typical household if
they can be shown to be within an affordabflhy index range (defined as a range of percentages of
median household income>tfaat appears reasonabtje when compared to other household expenditures.
The US EPA has established a burden threshold of 2.5 percent This approach is based on the
assumption that afibrdabffity to the median household served by the CWS can serve as an adequate
proxy for the affordabilhy of technologies to the system itself. The US 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. The US EPA believes that the national-level
affordabilhy criteria should describe the characteristics of typical systems and should not address
extreme situations where costs might be extremely low or excessively burdensome.
The national-level afibrdabflity criteria has three major o
ents: current annual water bills
(baseline), median household income and the afibrdability threshold... The baseline for annual water
bills was derived directly from data in the 199S CWSS. The median household income data were
Page -33-
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-erAec o> .inKing the C\VSS data with data in the 1990 Census using zip codes The Census income
aata uere convened from 1990 dollars to 1995 dollars using the consumer price index to facilitate
comparison with the CWS Survey data. To determine ;he maximum allowable increase that can be
imposed by treatment and still be considered affordable, current annual household water bills were
subtracted from the affordability threshold. This difference was compared with the convened
treatment costs to make the affordable technology determinations. This difference is called the
available expenditure margin. Table 5-2 details the national level of affordability established under
the guidance The cost basis for the reported numbers were 1995. The values for median household
income and median water bills were escalated to 1998 dollars using the Engineering New Record's
Skilled Labor Index and the Bureau of Labor Statistics's Consumer Price Index for Water and
sewerage maintenance.
r Table 5-2
National Level Affordability Criteria
Cost Basis 1995 Dollars (Cost Basis 1998 Dollars)
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 customto. 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 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
trc&tmcfit
The afibrdabffity 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 income
(MHI) to determine the financial impact of increased water costs on households.
Page -34.
-------
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
Consumer Expenditure Survey (CES) data, there is a :ategory 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 category called
energy and fuels in the analysis in the National-Level Affordability Document (US EPA, 1998b). The
subset of comparable expenditures from the CES data is contained in Table 5-3.
Table 5-3
Summary of Select Consumer Expenditures for All Consumer Units - 1995S
- - • •'". - '•-.'- .ifctiii^-Hiii ;\'-;4i;: •%'•."••-=>••;'
• % -MMW .*.,..*•• > .•• , . -. f ;.
•" . "" •'•£* *•'• '•"•:":="•?•,."*••*'?
Housing
Transportation
Food
Energy and Fuels
Telephone
Water and other Public Services
P nterf aintnent
Alcohol and Tobacco
>' '^fSJBIIIEilHriP'TnwffBHfffftfy^iy'^T
;^;-*:?J'';^ •^-••/.^•^M^jij.v^.' £'"4?f , .-
28.3%
. 16.3%
12.2%
3.3%
1.9%
O.T%
4.4%
1.5%
For more detaik cot the cona?arativehousehdd expend
Affordability Document (US EPA, 1998b).
5.4.1 Derivation eftbeAfTordabOity Threshold
The US 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 TaMe 5-3. Stakeholders were presented with an initial range for the affordability
threshold of 1.5% to 3% of the Mffl for each size category. Stakeholders, in general, did not express
a strong opinion about where the affordability threshold should be set within the range. The US EPA
selected 2.5% as the affordability threshold.
Page -35-
-------
Additional compliant technologies, other than centralized treatment, being considered include
Pomt-of-Entry (POE) and Point-of-L"se (POU) treatment units. Section 1412(b)(4)(E)(ii) of tne
SOW A identifies both POE and 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 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-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 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 "Technologies and Costs far Point-of-Entry and Point-of-USe
Devices for Control of Disinfection By-products" (US EPA, 19984) summarizes the US EPA's
approach to meeting the SDWA requirements on these devices as compliance technologies under the
Stage 1 DBP Rule. Estimated costs associated with POE and POU devices for use in meeting the
Stage 1 DBP Rule were also developed in this document for reverse osmosis and granular activated
carbon devices. As it is, POE devices would not be listed as an affordable compliance technology
using the selected affordabffity threshold. The POU costs support an affordability threshold between
2 and 2.5%. The POE costs support an aflfordabilhy threshold of 2.5% or greater.
Another important factor is that under this approach to national-level aflfordabilhy 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 The US EPA intends to conduct the Community Water Supply Surveys
every five years and win be able to track the increases o water bills due to u^atmert or infrastructure
repair. In the interim, between CWS Surveys, the US 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 wiD be higher, the available expenditure margins for comparison with arsenic'
treatment costs will be lower. The consumer price index data shows water prices increasing at a
faster rate than all items over the last 10 years (US EPA, 1998b). This implies that water prices
should increase faster than median household income and that the available expenditure margin will
decrease over time (see Table 5-2). The impacts of new regulations will further decrease the available
expenditure margin over time. Thus, while variance technologies are not available for the currently
Page-36-
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regulated contaminants, a decreasing available expenditure margin increases the likelihood of variance
technologies for future regulations
5.5 Determination of Household Afibrdability
Table 5-4 through 5-6 details the affordability assessment for the application of treatment
alternatives discussed in this document for control of DBFs under Stage I of the DBF rule. The
annual total cost reported represent the summation of annual total cost (in dollars) associated with
a compliance technology upgrade at 7 percent interest (US EPA, 1998c) and annual baseline
expenditures (US EPA, 1998b)
Page-37.
-------
Table 5-4
Affordability Assessment of Technologies
Examined for Removal of DBF Precursors
Treatment Option
Annual Cort
•MF^
. Annual
Baseline
Median
Water Cost
CBBH)*
Annual
Total Cost
MedfesHB
AwnlToUl
«f MefiaB
Population Sizes Ranging from 25 to 500
Fnhanced Coagulation
Enhanced Precipitanve
Softening
GAC - 10 min. EBCT
GAC - 20 min. EBCT
Nanofiltiation
12
13
265
655
311
234
246
247
. 499
889
545
33,094
0.78
0.75
1.5
2.7
1.6
Population Sizes Ranging from 501 to 3,300
Enhanced Coagulation
Enhanced Precipitative
Softening
GAC - 10 min. EBCT
GAC - 20 min. EBCT
Nanofiltiation
10
12
66
211
240
204
214
216
270
415
444
29,087
0.74
0.74
0.93
1.43
1.53
Population Sbes Ranging from 3,301 to 10,000
Enhanced Coagulation
Enhanced Praanifativf!
Softminff
GAC - 10 nn& EBCT
GAC - 20 min. EBCT
Nanofiltratiott (20°Q
Nanofiltiation (10aO
8
10
44
158
156
181
201
t
209
211
245
259
357
382,
1
' 0.70
0.71
0.83
1.21
1.20
1.29
•Source: Noricno/-L«W40brriaMO'Cn^
dollars)
NOTE: Technologies appearing in BOLD act not considered affordable
Page-38-
-------
Table 5-5
Affordability Assessment of Alternative
Disinfectants Schemes for DBF Control
Treatment Opttea
AmaalCwt .
ASM&.W2
9/BB$ '
Aaaoal
BaseUnc
MTaittim '
mHBQjMul •
Water Cost
. «/HH)*
Annual
Total COM
. - — taaw
vnnuuai nis
Income $J*
•' ', ""
•x-
Awnad Total
Cast«a%
•nicdiaft
Population Sizes Ranging from 25 to 500
Chlotamines as
Secondary Disinfectant
Ozone as a Primary
Disinfectant (Los. 1)
Ozone as a Primary
Disinfectant (Lot 3)
Ozone as a Primary
Disinfectant (\JM 5)
Chlorine Dioxide as a
Primary Disinfectant
(Log 1) • Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log 3)- Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log 5) -Manual
Chlorine Dioxide as a
Primary Disinfectant
n no 11 - Antmnarir
Chlorine Dioxide as a
U^B^nfft^u V%lAft^k4^4M*^^M6
IT l^^DttljT IvUUICCUDiiK
(Log3)-A«tOBUtfc
Chlorine Dioxide as a
tt^B^HM^M* Vki^£^Bf^M*A^M*
Primary DHUUcctaK
(LocS)-Astamatk
25
384
473
593
754
760
130
964
90 .
1,059
234
t
259
618
707
832
988
994
1,064
1,198
1003
1093
33,094
0.78
1.9
2.1
%
2.5
3.0
3.0
3J
16
3.6
33
•Source:
dollars)
NOTE: Technotogtes appearing m BOLD
Act (Escalaudto 1998
are not considered affordabk
Page -39-
-------
Table 5-5 (cont.)
Affbrdabilify Assessment of Alternative
Disinfectants Schemes for DBF Control
Treatment Qptiaa
AnmaiCort
npgrtde
(S/IDD
Aaaual
Baseline
**mMn^ '*
nlMMUl
Water Cost
.Annai
Total Cost
Mafias HH
.Awn** Total
eflfediaB
• lift income
Population Sizes Ranging from 501 to 3400
Chloramines as
Secondary Disinfectant
Ozone as a Primary
Disinfectant (Los. \)
Ozone as a Primary
Disinfectant (\JM 3)
Ozone as a Primary
Disinfectant (Lot 5)
\ o /
Chlorine Dioxide as a
(Log 1) - Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log 3) - Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log 5) - Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log 1) . Automatic
Chlorine Dioxide as a
Primary Disinfectant
(Log 3) - Automatic
Chlorine Dioxide as a
Primary Disinfectant
(Log 5) - Automatic
3
50
80
106
*
70
73
93
89
92
113.
204
207
254
284
310
274
277
297
293
29$
317
29,087
0.71
0.87
0.98
1.07
0.94
0.95
1.02
1.01
1.02
1.09
•Source SanauU**tAffiiTdabHity Criteria Undo- On 1996
dollars)
Page -40-
-------
Table 5-5 (com.)
Affordability Assessment of Alternative
Disinfectants Schemes for DBF Control
Treatment Option
Chloramines as
Secondary Disinfectant
•
Ozone as a Primary
Disinfectant (Los 1)
Ozone as a Primary
Disinfectant (Log. 3)
o
Ozone as a Primary
Disinfectant (LoE 5)
Chlorine Dioxide as a
Primary Disinfectant
(Logl)- Manual
Chlorine Dioxide as a
(Log 3) - Manual
Chlorine Dioxide as a
Primary Disinfectant
(Log S) - Manual
Chlorine Dioxide as a
Pnmary Disinfectant
(Log 1) - Automatic
Chlorine Dioxide as a
Primary Disinfectant
(Log "*) - Automatic;
Chlorine Dioxide as a
(Log S) - Automatic
AumaiCort
&BB}
. Aamial.
Baseline
Median
Water Cost
Pomlation SiZPff Wanoina fi
3
.38
66
64
24
26
43
31
33
"49
201
•
Aamni
Total Cost
Median HE
InffMMrfHy
•^^M^M^W fpvy .
•om 3401 to 10,000
197
232
260
2S8
218
220
237
225
227
243
29,714
Aamol Total
of Mediae
0.66
0.78
0.87
0.87
0.73
0.74
0.80
0.76
0.76
0.82
•Source: MafemU^ytfbdbfc^CiittrfeU^
dollars)
Page -41-
-------
Table 5-6
Aflbrdability Assessment or Technologies
Examined Tor DBF Removal
Treatment Option
Annual Cost
\*t*
UTTfTf Wf
swede
CS/HR)
Annual
Baseline
Median
Water Cost
warn*
Annual
Total Coat
. (S/BR)
Median HH
Income <$)•
Annual Total
Cost M a %
of Median
HH income
Population Sizes Ranging from 2S to 500
POE Reverse Osmosis
(Ground Water)
POU Reverse Osmosis
(Ground Water)
POEGAC
(Ground Water)
POUGAC
(Ground Water)
POE Reverse Osmosis
(Surface Water)
POU Reverse Osmosis
(Surface Water)
POEGAC
(Surface Water)
POUGAC
(Surface Water)
2,124
309
713
276
2,128
317
717
284
234
2,358
543
947
510
2,362
551
951
518
33,094
7.1
1.6
2.9
15
7.1
1,7
2.9
1.6
Population Sizes Ranging from 501 to 3400
POU Reverse Osmosis
(Ground Water)
POUGAC
(Ground Water)
POU Reverse Osmosis
(Surface Water)
POUGAC
(Surface Water)
263
234 .
' 264
235
204
•
467
438
468
439
29,087
I
1.6
1.5
1.6
1.5
' Source Saaonal-Level Affbrdability Crittna Under the 1996 Amendments to the Soft Drinking Wattr Act. (Escalated to 1998
dollars/
NOTE: Technologies appearing in BOLD are not considered affordable.
Pan -42-
-------
Table 5-6 (cont.)
Affbrdabilit) Assessment of Technologies
Examined for DBF Removal
Treatment Option
POU Reverse Osmosis
(Ground Water)
POUGAC
(Ground Water)
POU Reverse Osmosis
(Surface Water)
POUGAC
(Surface Water)
Annual Cost
assoc.W
Bp&vde
(S/HH)
Population
258
230
258
230
Annual
Median
Water Cost
«fl&W
Sizes Raoffine fi
201
Annual
Total CMC
9/BH)
Median, HH
Income
-------
Table S-7a
Stage 1 DBF Compliance Technologies Deemed Affordable
(Population Site Ranging from 25-500)
UnllTechttotegter
Technologies E:
OnefVthMi Cott&Uterattoni
for Removal of DBF Precursors
Enhanced Coagulation
Enhanced coagulation removes TOC
and DBF precursors through
coagulation, flocculaiion and
ADVANCED
The costs in this analysis are based on increasing Hie coagulant
(alum) dosage by 40 mg/L from 10 mg/L (Base Plant) to 50
mg/L. Similar levels of DBF control can be achieved at a lowei
total cost through the use of a smaller dosage increase in landcm
with a reduction in water pH. Higher MOM removals arc
achieved by decreasing coagulation pH and increasing ilic dose
of alum and ferric coagulants.
Enhanced Precipitalive
Softening
Enhanced precjpitativc softening
removes TQC and DBF precursors.
ADVANCED
Costs can vary with the type of softening performed, ilie iiuumcr
in which lime is handled and the method of sludge disposal
Increased NOM removal can be achieved elevating pi 110
approximately 10.8 or higher; delaying carbonate addition lor
several minutes; and delaying sludge recycling.
GAC Adsorption -
10 minute EBCT
An 90 percent reduction of TTHM
concentration in the GAC effluent is
expected at both 10 and 20 minute
EBCT.
BASIC
In the case of both 10 and 20 minute EBCT. GAC adsorption
occurs between filtration and contact basin. GAC replacement is
assumed. For this analysis, it was assumed that the entire plant
flow would be applied to the GAC process.
EBCT of 10 minutes at average flow and a regeneration
frequency of 180 days (carbon usage rate of 144 Ibs/MG treated)
Nanofiliration (NF)
Over 90%rejection of hardness-
fonning ions and between SO and 70
percent removal of dissolved solids.
INTERMEDIATE
•ally operate at feed pressures between 70 and
NF systems gei
ISOpsi.
To protect NF membranes, physical preirealmenl with
micfofiltralion and multi-media filters or chemical treatment
with anti-sealants and coagulants may be required
-44-
-------
Table 5-7a (conl.)
Stage 1 DBF Compliance Technologies Deemed Affordable
(Population Site Ranging from 25-500)
Unit Technologies ;,
•'• littiti! af iiflii* Gteiiwf
> •• ••''••i».1W*V' Wf*jK ¥^lp»^
&^^' ' > '&&*'$&'*•'>
:'QMfiMwr Skin ..
-&88&R*aidi»d'
,,", '.:**X O|M»«tttplCott*UkraUon«
•i" AS? " HI ' •
Alternative Disinfectant Schemes for DBF Control
Chloramincs as a
Secondary Disinfectant
Ozone as a Primary
Disinfectant (Log 1)
Ozone as a Primary
Disinfectant (Log 3)
Ozone as a Primary
Disinfectant (Loij 5}
Monochloramine reduces the rate of
TTHM formation in the distribution
system.
Speitel et al. (1993) found that
(biofilm on fiber media) removed up to
50% of THM precursors and up to
70% of HAA precursors.
'Giaidia log inactivation of 1 achieved.
Giaidia log inactivation of 3 achieved.
Giaidia log inactivaiion of 5 achieved.
INTERMEDIATE
INTERMEDIATE
INTERMEDIATE
INTERMEDIATE
For small systems, the ammonia feed is based on Hie use of
ammonia suttale. A residual chlorine to ammonia ratio or 4 1
was selected to control the growth of nitrifying bacteria and
reduce the formation of dichloroamine and irichloraniine. A pi 1
of 8.2 is considered to be suitable for rapid formation of
monochlonmine
In all cases ozone as a treatment alternative for DBF control is
h&fittt An the Kfilfkcemeiift nf chlnriiu* u/illi iwnnp far nrutrirv
disinfection and chlorine by chloramines for secondary
disinfection. Primary disinfection is considered to occur bci\\cen
sedimentation and filtration. In all cases, the following
flfflflwiptions are made*
-estimates are based on oxygen-based systems'
design flow;
-Design temperature of S°C; and
-Two parallel contactors, each treating one-half the design flow
Please Note: Increases in temperature and pH cause rapid decay
of ozone reducing disinfection capabilities.
Giardia log-inactivation of 1 consists of a theoretical hydraulic
detention time of 10 minutes and an ozone dosage of 2 ing/L
Giaidia log-inactivalion of 3 consists of a theoretical hydraulic
detention time of 10 minutes and an ozone dosage of 5 ing/L
Giardia log-inactivation of S consists of a theoretical hydraulic
detention time of 10 minutes and an ozone dosage of 7 mg/l .
Page-45-
-------
Table 5-7b
Stage 1 DBF Compliance Technologies Deemed Affordable
(Population Site Ranging from 501 - 10.000)
UaU Tectmetoek*
MbtJfa +t 1MM> font*** '
Operator Sk$
O" I1' • ' i •'. .
^?.;,. JL-A.:. •••
TecBoologict EiMBined for Removal of DBF Precursors
Enhanced Coagulation
Enhanced coagulation removes TOC
and DBF precursors through .
ADVANCED
The costs in this analysis are based on increasing ihe coagulant
(alum) dosage by 40 mg/L from 10 mg/L (Base Plant) to 50
mg/L. Similar levels of DBF control can be achieved at a lower
total cost through the use of a smaller dosage increase in laiidcm
with a reduction in water pH. Higher NOM removals arc
achieved by decreasing coagulation pH and increasing I lie dose
of alum and ferric coagulants.
Enhanced Precipilalrve
Softening
Enhanced predpiiative softening
removes TOC and DBF precursors.
ADVANCED
Costs can vary with the type of softening performed, the manner
in which lime is bandied and the method of sludge disposal
Increased NOM removal can be achieved elevating pi I to
approximately 10.8 or higher; delaying carbonate addition for
several minutes; and delaying sludge recycling.
GAC Adsorption -
10 minute EBCT
An 90 percent reduction of TTHM
(ration in the GAC effluent is
BASIC
expected at both 10 and 20 minute
EBCT.
In the case of both 10 and 20 minute EBCT, GAC adsorption
occurs between filtration and contact basin. GAC replacement is
assumed. For this analysis, it was assumed that the entire plant
flow would be applied to Ihe GAC process.
EBCT of 10 minutes at average flow and a regeneration
frequency of 186 days (carbon usage rate of 144 Ibs/MG treated)
90% reduction of TTHM'
BASIC
EBCT of 20 minutes at average flow and a regeneration
frequency of 60 days (carbon usage rale of 866 Ibs/MG treated)
Nanoftllration (NF)
Over 90Krejection of hardness-
forming ions and between 50 and 70
percent removal of dissolved solids.
INTERMEDIATE
NF systems generally operate at feed pressures between 70 and
ISOpsi.
To protect NF membranes, physical pretreatmenl with
nucrofillration and multi-media filters or chemical treatment
v/Jthjntijcalants and coagulants may be required
-46-
-------
Table 5-7b (conl.)
Stage 1 DBF Compliance Technologies Deemed Affordable
(Population Site Ranging from 501 -10,000)
Unit Tectakfiloijter
•
Chloraminesasa
Secondary Disinfectant
Ozone as a Primary
Disinfectant (Log 1)
Ozone as a Primary
Disinfectant (Log 3)
Ozone as a Primaiy
Disinfectant (Log S)
^fff^SK^,'.:^.
Alternative Dh
Monochloramine reduces the rale of
TTHM formation in (he distribution
system.
'
Speitel et al. (1993) found (hat
preozonation followed by biodegration
(biofilm on filter media) removed up to
50% of THM precursors and up to
70% of HAA precursors.
Giaidia log inactivation of 1 achieved.
Giaidia log inactivaUon of 3 achieved.
Giardia log inactivation of S achieved.
^SBfflSft-
liofectant Schemes foi
INTERMEDIATE
INTERMEDIATE
INTERMEDIATE
INTERMEDIATE
. : '•' * "4 '•• ^'QpBfiptfiiM Conslderatloni
r DBF Control
For small systems, the ammonia feed is based on the use of
ammonia solfate. A residual chlorine to ammonia ratio of 4 1
was selected to control the growth of nitrifying bacteria and
reduce the formation of dichloroamine and irichloramine A pi 1
of 8.2 is considered to be suitable for rapid formation of
monochloramine. Chloramine disinfection requires careful
monitoring of the ration of added chlorine to ammonia
Chloramines also possess less potency than other disinfectants
In all cases ozone as a treatment alternative for DBF conirul is
based on the replacement of chlorine with ozone for primary
disinfection and chlorine by chlorammes for secondary-
disinfection. Primary disinfection is considered to occur between
sedimentation and filtration. In all cases, the followmr
assumptions are made:
-estimates are based on oxygen-based systems;
-ozone generators are operated at 75% maximum capacity at
design flow;
-Design temperature of 5°C; and
-Two parallel contactors, each treating one-half the design flow
Please Note: Increases in temperature and pH cause rapid decay
Giaidia log-inactivation of 1 consists of a theoretical hydraulic
detention time of 10 minutes and an ozone dosage of 2 mg/L
Giardia log-inactivation of 3 consists of a theoretical hydraulic
detention time of 10 minutes and an ozone dosage of 5 mg/1
Giardia log-inactivation of S consists of a theoretical hydraulic
detention lime of 10 minutes and an ozone dosage of 7 nig/L
Page -47-
-------
Table 5-7b (com.)
Stage 1 DBF Compliance Technologies Deemed Affordable
(Population Size Ranging from SOI -10,000)
Alternative Disinfectant Schemes for DBF Control
Chlorine Dioxide as a
Primaiy Disinfectant
(Log I-Manual/Auto)
Used to control THM concentration.
Giaidia log inactivation of I achieved.
INTERMEDIATE
To control by product formation (i.e., chlorite and chlorate ions)
the chlorine dioxide dosage was limited to I mg/L Cost arc
included in this listing document for both manual and automatic
generators. Generator maintenance, in the case of manual
generators, is expected to require 3 times the hours per week
Giardia log-inactivalion of I consists of a theoretical contact
time of 60 minutes and an chlorine dioxide dosage of o 5 mg/l.
Chlorine Dioxide as a
Primaiy Disinfectant
(Log 3-Manual/Auto)
Giardia log inactivation of 3 achieved.
INTERMEDIATE
Giardia log-inaciivation of 3 consists of a theoretical contact
lime of 60 minutes and an chlorine dioxide dosage of I o mg/l.
Chlorine Dioxide as a
Primary Disinfectant
(Log 5 - Manual/Auto)
Giardia log inactivation of 5 achieved.
INTERMEDIATE
Giaidia log-inadivation of S consists of a theoretical contact
lime of 120 minutes and an chlorine dioxide dosage of 1.0 ing/1.
Page -48-
-------
Table 5-8
Stage 1 DBF Compliance Technologies Deemed Not Affordable
(Population Site Ranging from 25 - 500)
Unit Tccaaolegfe* ;
' :' '}•*??:
•
GAG Adsorption T
20 minuie EBCT
l^hlArim* nimtiflp MB A
Primary Disinfectant
(Log 1 - Manual/Auto)
Chlorine Dioxide as a
Primary Disinfectant
(Log 3 -Manual/Auto)
Chlorine Dioxide as a
Primary Disinfectant
(Lop 3- Manual/ Auto)
•!• •• ••••. siks^yl! ''--m/'m'ifmm™ iiif iVnt''!^!'!
Technologies Exai
90% reduction of TTHM
Alternative Dii
1 ICM! «A Mutant TUkJ mnnMtnlinn
ftitnlui tog inactivation of 1 achieved
.
Giardia tog inactivalion of 3 achieved.
Giardia log inactivation of 3 achieved.
;-:jfeBiSBt;-
mined for Removal of
BASIC
lofectant Schemes foi
INTERMEDIATE
/
INTERMEDIATE
INTERMEDIATE
: :! -•'. . ^ : ;:i : QfierttiQtt Gwsidenrtiona
'•'.vi!*:;^: "\.." ' • , =•
DBF Precursors
EBCT of 20 minutes at average flow and a regeneration
frequency of 60 days (carbon usage rate of 866 Ibs/MG treated)
r DBF Control
TA Muittml Iw nnwhid fitmuitinn (\ P rhlnrilf* anil rlilnr'iip innut
the chlorine dioxide dosage was limited to 1 mg/L Cost arc
included in this listing document for both manual and
-------
Table 5-9
Stage I DBF Technologies Deemed Affordable But
Not Included as Compliant Technologies
(Population She Ranging from 25-10,000)
Technologic
for DBF Removal
POU Reverse Osmosis
Greater than 93% reduction of TTHM
BASIC
A base plant (i.e., chlorine/chlorine) is assumed for primary
disinfection.
POU systems are assumed to be owned, operated and maintained
by the public water system or a individual under contract with
the public water system. The POU unit is assumed to be
equipped with an automatic shut-off device.
Quarterly replacement of the filler by trained personnel is
assumed. Membrane replacement is assumed to occur every IX
months.
POU G AC
Greater than 95% reduction of TTHM
expected.
BASIC
A base plant (i.e., chlorine/chlorine) is assumed for primary
disinfection.
POU systems are assumed to be owned, operated and maintained
by the public water system or a individual under contract with
the public water system. The POU unit is assumed to be
equipped with an automatic shut-off device.
Quarterly replacement of the filter by trained personnel is
-------
Table 5-10
Stage 1 DBF Emerging Technologies Deemed Non-Affordable
(Population Site Ranging from 25-500)
for DBF Removal
POE Reverse Osmosis
Greater than 93% nducUon of TTHM
BASIC
A base plant (i.e., chlorine/chlorine) is assumed for primary
POE systems are assumed to be owned, operated and maintained
by the public water system or a individual under contract wiili
the public water system.
The POE unit is assumed to be equipped with an automatic shut-
off device.
Yearly replacement of the filler and membrane by trained
personnel is assumed.
POE G AC
Greater than 95% reduction of TTHM
BASIC
Automatic shut-off devices and UV disinfection is assumed to IK
a part of the POE unit.
Yearly repla
of the filler by trained personnel is assumed
Page-51-
-------
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\
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i
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t
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Montgomery, James M., Consulting Engineers, Inc. (1992). Effect of C
on the Formati^ 0f pjgjnfection Bv-Products. Prepared for the AWWA.
Owen, et. al., (1993). "Characteristics of Natural Organic Matter and Its Relationship to
Treatabilhy." AWWA, Research Foundation.
Randtke, S. J. and Jepsen, C. P. (1982). "Effects of Salts on Activated Carbon Adsorption
of Fulvic Acids." J.AWWA. 74(2), p. 84.
Randtke, S. J., Thid, C: E., Liao, M. Y., and Yamaya, C. N. (1982). "Removing Soluble Organic
Contaminants by Lane-Softening." J.AWWA. 74(2), p. 84.
Randtke, S. J. (1988). "Organic Contaminant Removal by Coagulation and Related Process
Combinations" * AWWA80f 5Va. 40.
Rook, J. J. (1974). "Formation of Haloferms During Chtorination of Natural Waters."
WflUr TrBMHrPtt ft EMPflfftt*?" 23(2) p.. 234 >
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Rfl«m-C*mosb Drinking Water Fiher " Jnl. Environmental Health. 60 (2), pp. 14-16
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J AWWA. 72(8V p. 476.
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Serr-u-nens. M J . and Staples. A B (1986) "The \atural of Orgamcs Removed During Treatment
of Mississippi River Water " J AWWA. 78 (2). p 76
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111(6), p. 850. ' , ,
Snyder, J W. et. al, (1995). "Effect of Poirit-of-Use, Activated Carbon Filters on the
Bacteriological Quality of Rural Groundwater Supplies." Jnl. .Applied and Environmental
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Trihalomethane By-Products." J. AWWA. 81(8), p. 54.
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* i .
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APPENDIX A
RELEVANT PARTS OF SECTION 1412 OF THE 1996 SDWA AMENDMENTS
Page -58-
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SEC 105 TREATMENT TECHNOLOGIES FOR SMALL SYSTEMS
Section 1412(b)(4)(E) (42 U S.C- 300g-l(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 1 0,000 or
fewer but more than 3,300;
" (II) a population of 3,300 or
fewer but more than 500; and
"(HI) a population of 500 or fewer
but more than 25;
and thflt 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 mfprimum
contaminant level or treatment technique and
equipped with mechanical warnings to ensure that
ttuconuttiGftiiy HOQDCQ o»
operational problems. The Administrator shall not
include m the fist any point-of-use'treatment
technology, treatment technique, or other means to
achieve compliance with a maximum omAmnAamait
level or trtuHmunt' technique requirement for A
microbial contaminant (or an indicator of* .
mkrobtal contaminant). If the American National
Standards Institute
[[Page 1 10 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.
maximum contaminant level or treatment technique
Page -59-
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requirement unless they are independently
certified in accordance vMth such standards In
listing any technology, treatment techmaue. or
other means pursuant to this clause, the '
Administrator shall consider the quality of the
source water to be treated.
"(Hi) List of technologies that achieve
compliance.—Except as piovided 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 (HI) 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 (HI) of clause (ii) that are subject to the
regulation.
"(v) «NOTE: Records.» Technologies that
meet surface water treatment rule.-Whhm 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 (HI) of clause (ii).".
Page -60-
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SEC 111 TECHNOLOGY AND TREATMENT TECHNIQUES.
(a) Variance Technologies.-Section 14l2(b) (42 U.S C 300g-l(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;
"00 a population of 3,300 or fewer but more
than 500; and
"(iii) a population of 500 or fewer but more'.
than 25,
if, considermgthe quality of the source water to be.
treated, no treatment technology is listed for public-
water system* of that size under paragraph (4)(E).
Variance technologies identified by the Administrator
pursuant to. tins paragraph may not achievejTompHaiice
with the maxmuin contaminant level or treatment
technique requirement of such regulation, but shall
achieve thfe 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 -
identify any variance technology under this paragraph,
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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 puulic 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
affbrdability, 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
under this subparagraph. No public water system shall be
required to replace a variance technology during the
Page -62-
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useful lite 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)(£) and 141 S(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(bX4XE) and 1415(e).".
Page-63-
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APPENDIX B
PARTS OF SECTION 141S OF THE 1996 SDW>
Page -64-
-------
SEC i 16 SMALL SYSTEMS VARIANCES
Section 1415 (42 L" 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 i
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.(bX15) 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 *hft the conditions of paragraph (3).are met.
' ' (3) Conditions for granting variances.~A variance under
this subsection shafl be ayailab> only to a system-- '
' ' (A) that cannot afford to comply, ^accordance.
Wltu 8ffDfQuDlfi(yECXlwflft CStobilSuBO JJV * u!6> ~ f""1?' - ~
Administrator (or the State in the case ofr Statrthafc
M^h^Mh4feflMMBV£U^M*
responsiDuny
1413), with a national primary drinking water
including compliance through—
[[Page 110 STAT. 1642]]
'' (ii) alternative source of water supply; or
'' (iii) restructuring or consolidation (unless
the Administrator (or the State in the case of a
Page -65-
-------
Scate that has pnman. 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 14S2 or any other
Federal or State program.
"(5) «NOTE: Review.» Duration of variances.-The
Administrator (or the State in the case of a State th*t has
primary enforcement responsibility under section 1413) shall
review each variance granted under this subsection not less
often than every 5 vears after the fliuflp^flnc* date established
in the variance to --Pennine whether the system remains eligible
for the variance ana is conforming to each condition of the
variance.
'' (6) Ineligflrilhy for variances.-A variance shall not be
available under tb*y 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.
'' (7) Regulations and guidance.—
"(A) In general.-Not later than 2 years after the
Page -66-
-------
date or" 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(bXlS)) for
email systems and die 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(bXlSXA));aml
1 '(iv) infonnatioa requueagBts for variance
applications. ^
(B)
ri f*
QT
•«»•
, ,. .
and the Rural Utffitie* Service of ^De|Ha^&entof
Agriculture, shaft p«W^ imxjnnattott to assist tte
States in devdoping affbrdability criteria. The- "
•ffi^dabflhy «NOTE: Review » criteria shall be
reviewed by die States not less often than every 5 yean
to- deier mine if. changes are needed to thecriteria. .
'(8) Review by the administrator:*-
' ' (A) In general.-The Admimstrator sfaall-
periodically review the program of each State that has
primary enforcemem-responsibitity for public-water
Page -67-
-------
s> stems under section 1413 uith respect to variances to
determine whether the variances granted by the State
comply with the requirements ot this subsection. With '.
respect to affordability, the determination or'che
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.
11 (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.
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
Page -68-
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Administrator determines that the State decision does
not comply uith this subsection
"(B) Petition by consumers.-Not later than 30 days
after a State exercising primary enforcemeru
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.".
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