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   OFFICE OF GROUND WATER & DRINKING WATER
 UNITED STATES ENviROMENTAL PROTECTION AGENCY
 Dear Friends of Drinking Water:

 We are pleased to provide this packet of information about the Environmental
 Protection Agency's (EPA) ground water and drinking water programs.

 An important part of the  1996 Reauthorization of the Safe Drinking Water Act was
 an increased emphasis on public information and dialogue, citizen involvement and
 community partnerships. This information packet is just one of the ways EPA is
 demonstrating its commitment to that ethic.


 Enclosed is introductory information on the following topics:
 © Glossary ©f Terms


 We're committed to safe drinking water and extensive public information.
 We hope the enclosed materials will help you to TAP INTO IT and join with us in
 this important commitment.


 Sincerely,

"Cynthia Dougherty, Director
 Office of Ground Wafer and Drinking Wafer

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    OFFICE OF -GROUND WATER & DRINKING WATER
  UNITED  STATES ENVIROMENTAL  PROTECTION  AGENCY
Public Water System Facts and iBguresfas of RTO8
    Total Number of Public Water Systems (PWS)
    Community Water Systems (CWS)
    Nontransient, Noncommunity Water Systems
    Transient Noncommunity Water System
    CWSs using Surface Water (including CWSs designated as
    ground water under the direct influence of surface water)
    CWSs using Ground Water
Percent of Population Served by CWSs:

**People drink from more than one kind of system.
Number
 170,376
 54,367
 20,255
 95,754
                                  Population Served
                                               **
                                      252,530,574
                                          244,615
                                        16,756,549
  10,760               168,700,896
 43,607                83,829,678
 • ground water systems 33%
 • surface water systems 67%
                                          i (60%)
                                      /Very Small (
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   OFFICE OF GROUND  WATER & DRINKING WATER
 UNITED STATES'ENVIROMENTAL PROTECTION AGENCY
The Safewater web site provides you with
information on:
o  Y©ys" SoeaS drinking water quality
o  Ground water and sonrc© water
   protection programs
                             and tneis*
             ter activities far
           and parents
o Drinking water publications,, iraclisdlrtg
  "Water on Taps A Consymer!s Gosde to.
  the Nation's Drinking Water"
o Current activities of tine ©frlce of
  ©round Water sndi Drinking Water araJ'
               Ifci
                                                                                EPA 816/F-99-O15
                                                                                 September 1999

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                                                                   !-800-426-4791
                       Safe
                      TATER & D
   OFFICE OF GROUND WATER & DRINKING  WATER
  UNITED STATES ENVIROMENTAI PROTECTION AGENCY
The information specialists at the Hotline have expert knowledge of drinking water and
ground water programs.


The Hotline can take your order for materials and can also:

       o Clarify drinking water regy;atl@Rs, esola'-n ?s&&;fo:-i -Kit". jpiHeHnass for sMraldna;
         water,    provide updates swi proposs^ rules «rtd opportunities fesr pubSIs
                        iosi ©si s@i>s?cw
                                             lhead )jrctr-';t^-H, sote saurce aquifer
                 £6>ntsefts ixsr f&.;:.%
                      centre's pr-^
bottled water     horns water ti
                                                ;^ms aitd premfc
                                                 ifnt units.
     [International and local callers: 703-285-1093]  e-mail: hotline-sdwa@epa.gov
             Monday through Friday, 9:00 a.m. to 5:30 p.m., Eastern time
                                                                               EPA816/F-99-011
                                                                               September 1999

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  OFFICE OF GROUND  WATER  & DRINKING WATER
 UNITED  STATES  ENVIROMENTAL PROTECTION  AGENCY
The Water Resource Center can provide materials produced by EPA's Office of Water, which
includes the Office of Ground Water and Drinking Water.  Even if you don't know the specific
document you need, the Water Resource Center can help you find the information you are
looking for.
The Hesoiaree Center can provide:
o Books
o Training Materials
o Technical Reports
o Audio Tapes
o Lists of Technical Experts
                               o Education Kits and Science Projects    o Fact Sheets
                               o Guidance Manuals                    o Brochures
                               o Videotapes                           o CDs
                               o Models                              o Posters
                               o Catalogs of publications
For most materials, up to ten copies per person (depending on availability at the EPA warehouse)
are free. The Resource Center will provide information on how to order publications that are out
of print or are no longer available from EPA. These items may need to be purchased.

Want t® order a document?
A list of available publications' can be obtained from the Safewater web site, the Safe Drinking
Water Hotline, or the Water Resource Center.  Here are some examples of what you'll find:
8 1 6/F-99-00 i
                America's Drinking Water in 1 997
                Drinking Water and Health: What You Need to Know
                Emergency Disinfection of Drinking Water Fact Sheet
                Getting Involved  in Protecting Your Community's Source of Drinking Water
                It's Your Drinking Water: Get to Know it and Protect It
                Lead in Your Drinking Water
                Safe Drinking Water is in our Hands: Existing Standards and Future Priorities
                Safe Drinking Water is in our Hands (poster showing current standards)
                Water On Tap: A Consumer's Guide to the Nation's Drinking Water
       Mail or fax this form to:
       Water Resource Center
     401 M Street, SW, Room EB47
       Washington, DC 20460
        Fax: (202) 260-0386
 Or, place your order by phone or e-mail:
  E-maihcenter.water-resource@epa.gov
       Phone: (202) 260-7786
                                 Please print all information clearly
                                 Publication Number: _
                                 Title and # of copies:
                                                  (You may order up to 10 copies of each document Please allow 3-4 weeks for delivery.)
                                 Ship to:
                                 Name:	
                                 Address:;	
                                 City, State, Zip: .
                                 Daytime phone:
                                 E-mail address:
                                                                                      EPA 816/F-99-012
                                                                                       September 1999

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     OFFICE OF GROUND WATER & DRINKING WATER
   UNITED  STATES  ENVIROMENTAL PROTECTION  AGENCY
 One of the Office of Ground Water and Drinking Water's most valuable vehicles for public
 involvement is the National Drinking Water Advisory/Council.  Chartered under the original Safe
 Drinking Water Act in 1974 and an approved advisory committee under the Federal Advisory
 Committee Act, the Council's function is to support the drinking water program by providing
 advice and recommendations on drinking water issues.  The fifteen members are appointed by
 the Office of Ground  Water and Drinking Water, reflect a broad  base  of interests, and serve
 staggered three-year terms. The Council provide:; practical, independent advice on matters and
 policies related to drinking water quality and assists in identifying emerging issues.
                o  Proposed regulations and guidance required by the Safe Drinking Water Act
                o  Necessary special studies and research
                o  Promulgation and implementation of drinking water standards
                o  Identifying emerging environmental or health problems related to
                   potentially hazardous constituents in drinking water
                o  Actions to encourage cooperation and communication between EPA
                   and other governmental agencies, interested groups, the general public,
                   technical associations, and organizations concerned with drinking water
                   quality

              Council has addressed many critical drinking water issuesVsueh as:~"	""
                o  Consumer Confidence Reports                                "  ~.   ~ •
                o  Benefits of Developing Drinking Water Regulations
                o  Contaminant Candidate List and Contaminant Occurrence
                o  Drinking Water State Revolving Fund
                o  Operator Certification Guidelines
                o  Public Right-to-Know about Drinking Water Issues
                o  Regulation of High Risk Shallow Disposal Systems (Class V Injection Wells)
                o Small Drinking Water Systems
                o Source Water Assessment and Protection
The Council provides a structured framework for expert input in the development of drinking
water regulations.   Its working groups gather information, conduct informal meetings, and
provide advice to the full Council. All Council meetings are open to the public and include time
for public comment.

Although tight deadlines arid a diversity of opinions continue to be a challenge for all participants,
the consensus process of the Council has enhanced the quality and practicality of proposed
drinking water regulations. Likewise, interested parties have achieved a better understanding of
the Office of Ground Water and Drinking Water's (OGWDW) activities and have strengthened
their own partnerships with OGWDW arid with one another.  The National  Drinking Water
Advisory Council will  continue  to play an  important role as OGWDW expands its public
involvement and  public information programs.  OGWDW is committed to close and regular
consultation with stakeholders and openness in decision-making as away of doing business.
      For more information, see the National Drinking Water Advisory Council web site:
                     http://www.epa.gov/safewatsi-/ndwae/coisnciil.h4mj
                                                                                   EPA 816/F-S9-009
                                                                                    September 1999

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    OFFICE OF GROUND WATER & DRINKING WATER
  UNITED STATES  ENVIROMENTAL PROTECTION AGENCY
 The Environmental Protection Agency's Office of Ground Water and Drinking Water
 (OGWDW), together with states, tribes, and its many partners, protects public health by
 ensuring safe drinking water and protecting ground water.  OGWDW, along with EPA's
 ten regional drinking water programs, oversees implementation of the Safe Drinking
 Water Act, which is the national law safeguarding  tap water  in America.  The Safe
 Drinking Water Act requires public water systems to provide drinking water that meets
 standards  and protects  sources of drinking water,  including rivers, lakes, reservoirs,
 springs,  or ground water wells. Approximately 90%  of Americans rely on public water
 systems  for their drinking water at home; the other  10% have private wells, which are
 not federally regulated.  Almost everyone drinks water from a public system at some
 point: while at school, at work, in a restaurant, or on vacation.

 OGWDW develops and helps implement national  drinking water standards; oversees,
 assists and helps fund  state drinking water  programs and source water protection
 programs;  helps small drinking water systems; protects underground sources of drinking
 water through the Underground injection Control Program; and provides information to
 the public.  OGWDW also works in cooperation with states, tribes, and EPA's Office of
 Enforcement and Compliance Assurance to  guarantee  that water systems meet these
 protective  standards.
 OGWDW sets national standards for drinking water, which either limit the amount of a
 particular contaminant in drinking water or require a certain treatment to remove or
 inactivate a contaminant. Both types of standards protect public health. When setting
 these standards, OGWDW uses sound data and peer-reviewed science to focus on the
 contaminants which present the greatest public health  risk and which  appear most
 frequently in drinking water. OGWDW also identifies sub-populations most vulnerable to
 drinking water contaminants, such as infants, children, pregnant women, the elderly, and
 the immunocompromised, and considers the risk to these sensitive sub-populations when
 setting standards. As part of the standard-setting process, OGWDW relies on input from
 all interested parties, looks at whether drinking water regulations are cost effective,
 determines  appropriate procedures for analyzing samples of drinking water,  and
 identifies affordable ways to treat drinking water.

 Working with States and Tribes to Implement the Drinking Water Program

 States and tribes work directly with water systems to implement the national drinking
water program.  To implement the drinking water program (called primacy), each state
or tribe must establish a drinking water program that is at least as stringent as the
federal program (some states have stricter programs), assure that water systems meet
safety standards, and adopt and implement adequate enforcement procedures. If a state
or tribe is unable to meet the requirements for primacy, or is simply unwilling, EPA's
regional offices will directly implement the drinking water, program in that jurisdiction.
OGWDW provides grants, training, and technical assistance tojielp. states and  tribes
successfully carry out the provisions of the  Safe Drinking Water Act.  OGWDW also
administers the drinking water state revolving loan fund, and grants funds to states, that
loan money to water systems to install or upgrade facilities and to replace aging pipes
and other infrastructure. The fund's policy is to support all water systems in  need,
including assisting  small  and disadvantages^ communities, and protecting sources  of
drinking water from contamination.
                                                                             EPA816/F.99-007
                                                                             September 1399

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 Assistance for Small Drinking Water Systems

 The vast majority of water systems in the United States serve fewer than 3,300 people. Small
 water systems  incur greater costs per  household because they must spread the  cost of
 infrastructure improvement over a smaller customer base. In fact, small systems could incur
 three times as much cost per household to continue to provide safe drinking water in the future
 as compared to that of larger systems. OGWDW assists small systems by identifying affordable
 and effective ways for small systems to treat water for their customers and providing technical
 and financial assistance.

 Voluntary Programs with Water Systems: The Partnership for Safe Water

 The Partnership for Safe Water is a unique cooperative effort between OGWDW and over 100
 large water systems. Water systems that join the partnership provide protection beyond what
 is currently required by federal law to their customers from Ctyptosporldium, Giardia and other
 microbial contaminants.

 Protecting Drinking Water at its Source and Protecting Ground Water

 OGWDW is working with states so that they can determine, no later than 2003, how susceptible
 drinking water sources  are to contamination. States and  water suppliers will share  this
 information (compiled into source water assessments) with the public so that communities can
 protect their drinking water sources.   OGWDW also oversees programs that protect aquifers
 which serve as the primary source of drinking water for one or more communities (sole source
 aquifers), and works with states to implement wellhead  protection programs, under which
 states protect the land around wells from contaminants. Through the Underground injection
 Control  program, OGWDW protects  underground sources of drinking  water.  Injection deep
 into the earth is a common way of disposing of hazardous waste. If not injected properly, these
 wastes can contaminate sources of drinking water.  OGWDW sets standards for safe injection
 practices, and bans certain types of injection altogether.  A number of other EPA programs also
 protect drinking water from potential sources of contamination. For instance, the Superfund
 program cleans-up hazardous waste sites, while other programs regulate landfills, discharges to
 water, underground storage tanks, and chemicals used on farms and lawns.  OGWDW works
 with other EPA offices to support efforts to coordinate these  and  many other programs to
 provide comprehensive protection of the nation's ground water resource.

-• Collecting and Providing-Information to the'-Public'••                                     '  -

 Public  information and  public involvement  are critically important to the successful
 implementation of  the  drinking  water  program.   OGWDW works  through  an advisory
 committee, the National  Drinking Water Advisoi-y Council,  and solicits other input through
 public meetings with states, tribes, water systems,  environmental and  other groups, and  the
 public.  OGWDW  is working with these partners and others to provide information to citizens
 and communities on the quality of their local drinking water.  OGWDW collects information on
 every public water system, such  as how many people each system serves and whether each is
 meeting drinking  water  standards.  This information is stored in the  Safe Drinking Water
 Information System, and is used  to help OGWDW understand whether systems are complying
 with drinking water standards.  OGWDW is also collecting information  on the occurrence of
 contaminants which may need to be regulated in the future, and storing  this information in the
 National Contaminant Occurrence Database.  OGWDW is providing materials to help water
 systems  prepare  annual  water  quality reports (consumer  confidence reports)  and notify
 consumers of water emergencies,  and is helping  consumers use this  information to  make
 decisions. OGWDW maintains a web site (http://www.epa.gov/safewater/) and the Safe Drinking
 Water Hotline (I-800-426-4791)  to make drinking water information easily available, and  has
 also recently established the Drinking Water Academy to provide further training.

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*$>•«
         To assure that drinking water is safe, SDWA sets up
         multiple barriers against pollution. These barriers;
         include:  source  water  protection, treatment,
         distribution   system   integrity,   and   public
         information.  Public water systems are responsible
         for ensuring that contaminants in tap water do not:
         exceed the standards.  Water systems  treat the
         water, and  must test their  water frequently for
         specified  contaminants and report the  results to
         states.   If a water system is not meeting these
         standards, it is the water supplier's responsibility to
         notify its customers. Many water suppliers now are
         also required to prepare annual reports for their
         customers.  The public is responsible for working
         with  local water suppliers to set priorities, make
         decisions on funding and system improvements, and
         establish  programs to  protect  drinking water
         sources.  Water systems across the nation rely on
         citizen   advisory,  committees,   rate   boards,
         volunteers, and civic leaders to actively protect this
         resource in every community in America.
         Essential components of safe drinking water include
         protection and prevention.   States  and water
         suppliers must conduct assessments of water
         sources to see where  they may be vulnerable to
         contamination. Water systems may also voluntarily
         adopt  programs to protect  their watershed or
         wellhead and states can use legal authorities from
         other laws to prevent pollution.  SDWA mandates
         that states have programs to  certify water system
         operators and make sure that new water systems
         have the technical, financial,  and  managerial
         capacity to provide safe drinking water.

         SDWA also sets a framework for the Underground
         Injection  Control program (UIC) to control the
         injection  of wastes  into ground water. EPA and
         states  implement the  UIC program,  which  sets
         standards for safe  waste injection practices  and
         bans certain types  of injection altogether.  AH of
        these programs help prevent the contamination of
        drinking water.
        Setting National Dresklfig Warar Sfemrferefe

        EPA sets national  standards' for tap water which
        help ensure consistent quality in our nation's water
        supply. EPA prioritizes contaminants for potential
        regulation based on risk and how often they occur in
 What's a public water system?

 Ail public water systems must have
 at least IS service connections or
 serve at least 25 pe@pie per
 60 days of th© year.
 water systems df^sreMfy based ©n
 f&elr type and size:

 Community Water System (there are
 approximately 55,000) -A public water
 system that serves the same people year-
 round. Most residences including homes,
 apartments, and condominiums in cities,
 small towns, and mobile home parks are
 served by community water systems."   4

 Non-Community'Water System -A
 public water system that serves the public
 but does not serve the same people year-
 round. There are two types of non-
 communHy systems:

 N©n-Transient Non-Community
 Water System (there are approximately
 20,000) -A non-community water
 system that serves the same people more
 than six months per year, but not year-
 round, for example, a school with its own
 water supply is considered a non-
 transient system.

 Transient non-community water
 system (there are approximately 95,000)
- A non-community water system that
serves the public but not the same
individuals for more than six months, for
example, a rest area or campground may
be considered a transient water system.

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 EPA sets primary drinking water
 standards through a three-step
 process:

 First, EPA identifies contaminants that may
 adversely affect public health and occur in
 drinking water with a frequency and at
 levels that pose a threat to public health.
 EPA identifies these contaminants for
 further study, and determines
 contaminants to potentially regulate.

 Second, EPA determines a maximum
 contaminant level goal for contaminants it
 decides to regulate. This goal is the level
 of a coptaminant in drinking water below
 which there is no known or expected risk
 to health.  These goals allow for a margin
 of safety.

 Third, EPA specifies a maximum
 contaminant level, the maximum
 permissible level of a contaminant in
 drinking water which is delivered to any
 user of a public water system. These
 levels are enforceable standards, and are
 set as close to the goals as feasible.

 SDWA defines feasible as the level that
 may be achieved with the use of the best
 technology, treatment techniques, and
 other means which EPA finds (after
 examination for efficiency under field
 conditions)  are available, taking cost into
 consideration.

When it is not economically or technically
feasible to set a maximum level, or when
there is no reliable or economic method
to detect contaminants in the water, EPA
instead sets a required Treatment
Technique which specifies a way to treat
the water to remove contaminants.
 water supplies (to aid in this effort, certain water
 systems monitor for the presence of contaminants
 for which no national standards currently exist and
 collect information on their occurrence).  EPA sets a
 health goal based on risk (including risks to the most
 sensitive  people, ..e.g. infants,  children,  pregnant
 women, the elderly and the immune-compromised).
 EPA then sets a legal  limit for the contaminant in
 drinking water or a required treatment technique -
 this limit or treatment technique is set as close to
 fche health goal as feasible. EPA also performs a. cost-
 benefit analysis  and obtains input from  interested
 parties when  setting standards.  EPA is currently
 evaluating the  risks  from  several specific health
 concerns, including: microbial contaminants  (e.g.
 Cryptospor/d/um); the byproducts of drinking water
 disinfection; radon; arsenic; and water systems that
 don't currently disinfect their water but get it from
 a potentially vulnerable ground water source.
 EPA provides grants, to implement state drinking
 water  programs,  and to help each state set up a
 special fund to  assist  public  water systems  in
 financing  the costs  of improvements (called the
 drinking water state revolving fund). Small water
 systems are given special consideration, since small
 systems may have a more difficult time paying for
 system improvements due to their smaller customer
 base.  Accordingly, EPA and  states provide  them
 with extra assistance (including training and funding)
 as well as allowing, on a case-by-case basis, alternate
 water treatments which are less expensive, but still
 protective of public health.
National  drinking  water standards  are legally
enforceable, which means that both EPA and states
can take enforcement actions against water systems
not meeting safety standards. These actions focus
on contaminants which pose the  greatest risk to
public  health, e.g.,  microbiological contaminants,
lead and copper, and other contaminants which, if
present in drinking water, may have immediate
(acute) effects on health.  EPA and states  may issue
administrative orders, take  legal  actions, or fine
utilities. EPA and states also work to increase water
system's understanding of, and compliance  with,
standards.

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      1996 SDWA Amendment Highlights:

 Consumer Confidence Reports
 Community water systems must prepare and distribute
 annual reports about the water they provide, including
 information on detected contaminants, possible health
 effects, and the water's source.

 Cost-Benefit Analysis
 EPA must conduct a thorough cost-benefit analysis for every
 new standard to determine whether the benefits of a
 drinking water standard justify the costs.

 Drinking Water State Revolving Fund
 States can use this fund to help water systems make
 infrastructure or management improvements or to help
 systems assess and protect their source water.

 Hicrobial Contaminants and Disinfection
 Byproducts
 EPA is required to strengthen protection for microbial
 contaminants, including Cryptosporidium, while
 strengthening control over the byproducts of chemical
 disinfection. Two new drinking water rules in November
 1998 addressed these issues; others will follow.

 Operator Certification
 Water system operators must be certified to ensure that
 systems are operated safely.  EPA issued guidelines in
 February 1999 specifying minimum standards for the
 certification and Decertification of the operators of
 community and nontransient, noncommunity water
 systems.

 Public information & Consultation
 SDWA emphasizes that consumers have a right to know
 what is in their drinking water, where it comes from, how it
 is treated, and how to help protect it.  EPA distributes
 public information materials (through its Safe Drinking
 Water Hotline, Safewater web site, and Water Resource
 Center) and holds public meetings, working with states,
 tribes, water systems, and environmental and civic groups, —
 to encourage public involvement.          ~

 Small Water Systems
 Small water systems are given special consideration and
 resources under SDWA, to make sure they have the
 managerial, financial, and technical ability to comply with
 drinking water standards.

 Source Water Assessment Programs
 Every state must conduct an assessment of its sources of
 drinking water (rivers, lakes, reservoirs, springs, and ground
water wells) to identify significant potential sources of
contamination and to determine how susceptible the
sources are to these threats.
 SDWA recognizes that since everyone drinks water,
 everyone has the right to know what's in it and
 where it comes from. All water suppliers must notify
 consumers quickly when there is a serious problem
 with water quality. Water systems serving the same
 people year-round must provide  annual consumer
 confidence reports on the source and quality of their
 tap water.  States and EPA must  prepare annual
 summary reports of water system compliance with
 drinking water safety  standards  and make  these
 reports available to the public. The public must have
 a chance to be involved in developing source water
 assessment  programs,  state plans to use drinking
 water state revolving loan funds,  state capacity
 development plans, and state operator certification
 programs.
To learn more about the Safe Drinking Water Act or
drinking  water in general, call the Safe Drinking
Water Hotline at 1-800-426-4791, or visit EPA's
Office of Ground Water and Drinking Water web
site: http;//www.epa.gov/safewater/.

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     OFFICE OF GROUND WATER & DRIN'KING  WATER
   UNITED  STATES  ENVIROMENTAL PROTECTION AGENCY
 These definitions are not intended to be
 complete or to have legal force, but rather to
 help consumers quickly understand drinking
 water-related terms in the context of their
 daily lives.
           si: The level of lead or copper which,
 if exceeded, triggers treatment or other
 requirements that a water system must follow.

 Acute Health Effeefi: An immediate (i.e. within
 hours or days) effect that may result from
 exposure to certain drinking water
 contaminants (e.g., pathogens).
       n A natural underground layer, often of
 sand or gravel, that contains water.
                       y; The water
 treatments) that EPA certifies to be the most
 effective for removing a contaminant.

• Chronic Health Effect: The possible result of
 exposure over many years to a drinking water
 contaminant at levels above its Maximum
 Contaminant Level.

 Cofifos-m: A group of related bacteria whose
 presence in drinking water may indicate
 contamination by disease-causing
 microorganisms.

 Community Water System', A water system
 which supplies drinking water to 25 or more of
 the same people year-round in their residences.

 Compliance: The act of meeting all state and
 federal drinking water regulations.

 Contaminant: Anything found in water
 (including microorganisms, minerals, chemicals,
 radionuclides, etc.) which may be harmful to
 human health.

 Cryptosporidlium: A microorganism commonly
 found in lakes and rivers which is highly
 resistant to disinfection. Cryptosporid/um has
 caused several  large outbreaks of
 gastrointestinal illness, with symptoms that
 include diarrhea, nausea, and/or stomach
 cramps. People with severely weakened
 immune systems (that is, severely immuno-
 compromised) are likely to have more severe
 and more persistent symptoms than healthy
 individuals.

 Disinfectant: A chemical (commonly chlorine,
 chloramine, or ozone) or physical process (e.g.,
 ultraviolet light) that kills microorganisms such
 as bacteria, viruses, and protozoa.

 Distribution System: A network of pipes
 leading from a treatment plant to customers'
 plumbing systems.
            State or EPA permission for a
 water system not to meet a certain drinking
 water standard.  An exemption allows a system
 |&ditional time to obtain financial assistance or
 make improvements in order to come into
 compliance with the standard. The system
 must prove that: (I) there are compelling
 reasons (including economic factors) why it
 cannot meet EPA health standards (Maximum
 Contaminant Levels or Treatment Techniques);
 (2) it was in operation on the effective date  of
 the requirement, and (3) the exemption will
 not create an unreasonable risk to public
 health. The state must set a schedule under
 which the water system will comply with the
 standard for which it received an exemption.
        I Waters Water that has been treated
 and is ready to be delivered to customers. See
 Source Water.
        lam&lia: A microorganism frequently
 found in rivers and lakes, which, if not treated
 properly, may cause diarrhea, fatigue, and
 cramps after ingestion.
              : The water that systems pump
 and treat from aquifers (natural reservoirs
 below the earth's surface).
              f. An EPA document that
 provides guidance and information on
 contaminants that can affect human health and
 that may occur in drinking water, but which
 EPA does not currently regulate in drinking
 water.

 inorganic Contaminants: Mineral-based
 compounds such as  metals, nitrates, and
 asbestos. These contaminants are naturally-
 occurring in some water, but can also get into
 water through farming, chemical
 manufacturing, and  other human activities.
 EPA has set legal limits on IS inorganic
 contaminants.

 Maximum Contaminant Level (MCL): The
 highest level of a contaminant that is allowed '
 in drinking water. MCLs are set as close to the
 MCLG as feasible using the best available
 treatment technology. MCLs are enforceable
 standards.

 Maximum Contaminant Level! Goa! (HCLC3):
 The level of a contaminant in drinking water
 below which there is no known or expected
 risk to health. MCLGs allow for a margin of
 safety. MCLGs are non-enforcable health goals.

 Microorganisms: Tiny living organisms that can
 be seen only with the aid of a microscope.
 Some microorganisms can cause acute health
 problems when consumed in drinking water.
Also known as microbes.
                                                                                EPA 816/F-99-O13
                                                                                September 1999

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 Monitoring: Testing that water systems must
 perform to detect and measure
 contaminants.  A water .system that does not
 follow EPA's monitoring methodology or
 schedule is in violation, and may be subject
 to legal action.

 Non-Transient, Mora-Community Water
 System: A water system which supplies
 water to 25 or more of the same people at
 least six months per year in places other
 than their residences.  Some examples are
 schools, factories, office buildings, and
 hospitals which have their own water
 systems.

 Organic Contaminants: Carbon-based
 chemicals, such as solvents and pesticides,
 which can get into water through runoff
 from cropland or discharge from factories.
 EPA has set legal limits on 56 organic
 contaminants.

 Pathogen: A disease-causing organism.

 Primacy State: A State that has the
 responsibility and authority to administer
 EPA's drinking water regulations within its
 borders. The State must have rules at least
 as stringent as  EPA's.

 Public Notification: An advisory that EPA
 requires a water system to distribute to
 affected consumers when the system has
 violated Maximum Contaminant Levels or
 other regulations.  The notice advises
 consumers what precautions, if any, they
 should take to protect their health.

 Public Water System (PWS); Any water
 system which provides water to at least 25
 people for .at least 60 days annually. There .
 are more than  170,000 PWSs providing
 water from wells, rivers and other sources to
 about 250 million Americans. The others
 drink water from private wells. There are
 differing standards for PWSs of different
 sizes and types.

 Radionuelides: Any man-made or natural
 element that emits radiation and that may
 cause cancer after many years of exposure
 through drinking water.

 Raw Water: Water in its natural state, prior  .
 to any treatment for drinking. See finished
 water.

 Sample: The water that is analyzed for the
 presence of EPA-regulated drinking water
 contaminants.  Depending on  the regulation,
 EPA requires water systems and states to
 take samples from source water,  from water
 leaving the treatment facility, or from the
 taps of selected consumers.

 Sanitary Survey: An on-site review of the
water sources, facilities, equipment,
 operation, and maintenance of a  public
water systems for the purpose of evaluating
the adequacy of the facilities for producing
and distributing safe drinking water.
 Secondary Drinking Water Standards: Non-
 enforceable federal guidelines regarding
 cosmetic effects (such as tooth or skin
 discoloration) or aesthetic effects (such as
 taste, odor, or color) of drinking water.

 Sole Source Aquifer: An aquifer that supplies
 50 percent or more of the drinking water of
 an area.
   uree Water: Water in its natural state,
 prior to any treatment for drinking. See
 finished water.

 Surface Water: The water that systems
 pump and treat from sources open to the
 atmosphere, such as rivers, lakes, and
 reservoirs.

 Transient, Non-Community Water System: A
 water system which provides water in a  •
 place such as a gas station or campground
 where people do  not remain for long periods
 of time. These systems do not have to test •
 or treat their water for contaminants which
 pose long-term health risks because fewer
 than 25 people drink the water over a long
 period. They still must test their water for
 microbes and several chemicals posing short-
 term health risk.

 Treatment Technique: A required process
 intended to reduce the level of a
 contaminant in drinking water.

 Turbidity: The cloudy appearance of water
 caused by the presence of tiny particles.
 High levels of turbidity may interfere with
 proper water treatment and monitoring.

 Variance: State or EPA permission not to
 meet a certain drinking water standard.  The
 water system must prove that: (I) it cannot
 meet a Maximum Contaminant Level, even
 while using the best available treatment
 method, because  of the characteristics of the
 raw water, and (2) the variance will not
 create an unreasonable risk to public health.
 The State or EPA must review, and allow
 public comment on, a variance every three
 years.  States can also grant variances to
 water systems that serve small populations
 and which prove that they are unable to
 afford the required treatment, an alternative
 water source, or otherwise comply with the
 standard.

Violation; A failure to meet any state or
federal drinking water regulation.

Vulnerability Assessment: An evaluation of
 drinking water source quality and its
vulnerability to contamination by pathogens
 and toxic chemicals.

Watershed: The land area from which water
•drains into a stream, river, or reservoir.

Wellhead Protection Area: The area
surrounding a drinking water well or well
•field which is  protected to prevent
contamination of the wel!(s).

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OFFICE  OF GROUND WATER  & DRINKING WATER
             401 M St. SW, MC 4601
             Washington, DC 20460
             (202) 260-5543 telephone
             (202) 260-4383 facsimile
          http://www.epa.gov/safewater/

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