Protecting  Drinking Water
                     Sources
SAFE  DRINKING  WATER  ACT  •  1974-2004 • PROTECT  OUR  HEALTH  FROM  SOURCE  TO  TAP
The 1996 Amendments to the Safe  Drinking Water
Act (SDWA) took a major new step  in drinking
water protection by mandating that states perform
a source water assessment for each  public water
system.  States are responsible       ^^^^^^^^^_
for completing assessments for
public water systems in major
metropolitan areas, small towns,
schools, restaurants, and other
public facilities that have a well or
surface  water supply. (Private wells
are not  included in this effort.)
After a state's Source Water
Assessment Program (SWAP)
is approved by the United
States Environmental Protection
Agency (US EPA), the state  has
two years, with a possible 18
months extension, to conduct
an assessment for each  public
water system  and make  these
assessments available to the public. US  EPA has
approved 52  SWAP  programs.  States must complete
all the assessments  in the state no later  than 3 years
after US EPA  approves the programs.

The  source water assessment programs established
by each state differ, depending on the nature and
threats to the water resources and the drinking water
program priorities in a particular state.  However,
each assessment program must include four major
elements:

      •  delineating  (or  mapping) the source
     water protection areas

      •  conducting  an inventory of potential
     sources  of contamination in those areas

      •  determining the susceptibility of public
     water systems to those contamination
     sou rces

      •  releasing the results of the
     determinations to the  public

Following successful completion of these elements for
each assessment, communities can use the  resulting
information to identify priority actions for protecting
their drinking water sources.
                                                     Source Water Assessments
                                                     The four  assessment steps  are described in more detail
                                                     below.
                                  Step 1:
                                  Delineate the
                                  sou rce water
                                  assessment area

                                  For each
                                  grou nd water
                                  well or surface
                                  water system
                                  that supplies
                                  public drinking
                                  water, states
                                  must  delineate
                                  and map the
                                  boundaries of
                                  each  protection
                                  area.
  For ground water systems, states commonly use
  available information about ground water flow and
  recharge to determine the source water protection
  area  around a well or well field.

  For surface water systems drawing water from a
  stream,  river, lake, or reservoir, the land area  in
  the watershed upstream of the  intake  is identified
  on a  map. A topographic map  is used to identify
  the perimeter of the area that provides water to the
  water system's intake. Some states plan to divide  the
  watershed area into segments—areas  that are closest
  to  the intake where most types  of contamination
  sources  may be found to be significant, and other
  more distant areas. The entire  watershed area up to
  the state's boundaries is required to be delineated
  and mapped, but the level  of detail in the inventory
  of  potential pollution sources and  the susceptibility
  determination can vary in the different segments.
  Coordination across state boundaries is encouraged
  where appropriate.

Step 2: Conduct an  inventory of potential sources  of
contamination

  In  the second step of an assessment, the state
  identifies the  potential sources  of pollutants that
  could contaminate  the water supply. This inventory

-------
  usually results in a  list and a map of facilities and
  activities within  the delineated area that may release
  contaminants into the underground water supply
  (for wells) or the watershed of the river or lake (for
  surface water sources).

  Some examples  of the many different types  of
  potential pol I utant sou rces include landfills,
  underground or  above-ground  fuel storage tanks,
  residential  or commercial septic systems, urban
  runoff from  streets and  lawns, farms and other
  entities that apply pesticides and fertilizers, and
  sludge disposal  sites.

Step 3:  Determine the susceptibility of the water
supply to contamination

  In  the third  step—the susceptibility determination
  —the state combines the inventory results with other
  relevant information to  decide  the likelihood of
  contamination of the water supply by the identified
  significant  potential sources of contamination.
  This  critical step makes the assessments useful for
  communities. It  helps local decision-makers consider
  priority approaches for  protecting the drinking water
  supply  from contamination. Some  states prioritize
  the potential for contamination from  the specific
  potential contamination sources or to individual
  chemicals that could pollute the water. Other states
  assign  a susceptibility ranking of high, medium, or
  low to the water sources.

Step 4:  Provide the assessment results to the public

  After the state completes the assessment for a
  particular water  system, it will summarize the
  information for the  public. Such summaries will
  help communities better understand the potential
  threats to  their water supplies and identify  priority
  needs for protecting the water from contamination.
  This  summary information must be included in water
  systems' Consumer  Confidence Reports (annual
  water quality reports).  Local communities, working
  in  cooperation with local, regional, and state
  agencies,  can use the information gathered through
  the assessment process  to create a broader source
  water protection program to address  current and
  future threats to the quality of their drinking water
  supplies.

Source Water Protection

While source water protection was not specifically
mandated by SDWA, US EPA and its partners
encourage states,  tribes,  and communities to use the
information  from source  water assessments to protect
the delineated source water protection  areas  from
identified pollution sources of major concern. Using
a partnership  approach,  community groups and  local
officials can  plan  how to  best manage those  identified
potential sources and  prevent new contaminant threats
in  the source water area.

Many source water protection areas will include
multiple jurisdictions,  i.e., the city or county  where the
source water intake or wellhead is located, and  other
               towns, counties, or states upstream  or upgradient from
               the public water system. Local  political authorities
               may be able to adopt protection measures within
               their jurisdiction, but to achieve effective protection
               beyond their boundaries, they  will usually have to
               work with neighboring jurisdictions or federal  or state
               authorities.

               Communities use a wide array  of different source
               water protection methods to prevent contamination  of
               their drinking water supplies. One management option
               involves regulations, such as prohibiting  or restricting
               land uses that may release  contaminants  in critical
               source water protection  areas.  Along with regulations,
               many communities  hold  local events and  distribute
               information to educate  and encourage citizens and
               businesses to recycle  used oil,  limit  their  use  of
               pesticides, participate in watershed  cleanup activities,
               and a  multitude of other prevention  activities. Another
               aspect of a source  water protection  program  can be
               the purchase of land or  the creation of conservation
               easements to serve as a protection zone near the
               drinking water source. For an effective protection
               program, communities should consider using  a variety
               of prevention measures.

               To assist their efforts to  protect areas  which surround
               surface water sources of drinking water, local
               authorities can look to  Section 303  of the Clean
               Water  Act. This section  requires each state to  review
               its water quality standards every three years.  The
               review must consider the "use  and value" of the water
               as a drinking water supply.  States that adopt  water
               quality standards to protect all  public water supplies
               and prospective supplies can enforce these standards
               under  state and federal  law to  control pollution.

               To augment local ground water protection efforts,
               some states  use ground  water quality standards that
               work much like the Section  303 program  for surface
               water.  Some states  also  use a permit program to
               regulate pollution that can  contaminate ground
               water.  The federal  Underground  Injection Control
               (UIC) program  regulates the use of wells  as a  means
               to dispose of waste, and the Resource Conservation
               & Recovery Act (RCRA) regulates the management
               of hazardous and  non-hazardous waste that can
               contaminate ground water.

               For More Information:

               For further information  on your state's source  water
               assessment program and how to participate, contact
               the agency in your  state that is  managing the program.
               Call the Safe Drinking Water Hotline at 1-800-426-
               4791,  or visit the safewater web site at www.epa.
               gov/safewafer for more  information, state contacts,
               and links to other organizations that may be active
               with source water  protection in  your area. Your local
               water supplier may also have more information about
               opportunities to become involved in the source water
               assessment process. You can call the phone number on
               your water bill  or contact your  local health department
               for information on  your  water supplier.
Office of Water (4606)
www.epa.gov/safewater
EPA 816-F-04-032 June 2004

-------