United States Office of Water EPA 816-F-98-006
Environmental Protection (4606) October 1998
Agency : ••
Information Available from the Safe
jinking Water Information System
. Safe Drinking Water Information System/Federal Version (SDWIS/FED) is an Environmental
Protection Agency (EPA) database storing basic information about the nation's drinking water supply.
This information comes from the states and EPA's regional offices and is reported for every public
water system in the United States. This fact sheet provides information about the type of information
available in SDWIS/FED.
OVERVIEW:
The Safe Drinking Water Act (SDWA) gives EPA the authority to regulate public drinking
water supplies. Using its authority under this law, EPA has set health-based standards for
contaminants that may be found in drinking water. EPA regulates over 80 contaminants in drinking
water to ensure that all water supplied by public water systems in the United States meets minimum
health-based standards to guarantee safety and public health. EPA works with states, which oversee
public water systems within their jurisdictions, to make sure the systems are in compliance with EPA
standards. States report information quarterly to EPA on whether any public water systems have
violated these standards. This information is collected and stored in SDWIS/FED, and used to: 1) help
EPA monitor the safety of the nation's drinking water supply and assist in understanding the status of
drinking water rule implementation, 2) collect information on additional contaminants that may some
day be regulated, 3) report information to the public and to Congress on the status of public drinking
water, and 4) help EPA and states determine when additional actions are necessary to protect drinking
.water.
TYPES OF INFORMATION IN SDWIS/FED:
SDWIS/FED contains basic information on every public water system, including, but not limited to:
• the name of the public water system
• information about the type of area served by the water system (e.g., households, schools,
restaurants, gas stations, or rest areas)
• how many people the water system serves and its operating season (year round or seasonal)
• who regulates the water system (typically, states regulate systems within their jurisdictions;
EPA currently regulates Tribal systems and systems in Wyoming)
• when (or if) a water system has violated any national drinking water standard
• what (if any) follow-up actions, including enforcement actions, have been taken to make sure
the water system returns to compliance following a violation
Other types of optional information can be stored in SDWIS/FED. This information is
discussed in further detail in this fact sheet. SDWIS/FED can store a great deal of information about
public water systems, and EPA and states work together to determine when and if mandatory
reporting requirements should change. New requirements will be noted throughout this fact sheet.
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INFORMATION EPA HAS FOR EVERY PUBLIC WATER SYSTEM:
EPA maintains information on every public water system (PWS), even those which are no
longer active water suppliers.
Data EPA has for all public water systems:
• The nine character PWS ID number that uniquely identifies each public water system as well
as the state or EPA regional office which oversees its compliance with drinking water
regulations
• Information on whether the system is currently active or is inactive
• If the system is not active, the date it ceased to operate
• Whether the system is: a Community (year-round, residential population -- e.g. a city); Non-
Transient Non-Community (serves the same population for at least six months a year,
although the system is not the primary water supplier -- e.g. many businesses or schools); or
Transient Non-Community (varying population -- e.g. a rest area) water system
• The retail population served by the water system
• The number of service connections for each water system (defined as the number of
households or businesses connected to the water system)
• Basic information on a water system's source of water. At least one source must be reported
for all systems, and all surface water sources must be reported. This information is then used
to determine the primary source of drinking water
• The primary source of the drinking water (because regulations are currently more stringent for
surface water than for ground water systems, the existence of any surface water source
classifies a water system as a surface water system)
• If the water system purchases its water, the ID number of the system that sells the water
• The past names of the water system and when they changed (if applicable)
• The date of the most recent update to SDWIS/FED for the system
• Whether a water system is a Significant Non-Complier (a system that has been a consistent
and serious violator of EPA standards) or an Exception (a significant non-complier not
addressed in a timely or appropriate manner, i.e., through formal enforcement)
New Reporting Requirements: These new requirements will be implemented beginning in the year
2000. For those marked with an * this information is already reported by most states.
• * The county(s) served by the water system
• * Service Area Characteristics (whether the area is residential, a mobile home park, a rest
area, etc.)
• * Water system owner type (local, state or federal government, private, etc.)
• The city(s) served by the water system, if the water system serves a city
• Additional address data (the mailing address of the owner/operator/primary contact and the
physical location of the treatment plant indifferent from the mailing address)
• The latitude and longitude (and all required method, accuracy, and description codes under
EPA's locational data policy) of all sources of water (surface water intakes and ground water
wellheads) for all community and non-transient non-community water systems; states are
encouraged (but not required) to report the latitude and longitude of any treatment plants
• Treatment data including all sources and treatment plants, reporting explicitly that no
treatment is in place, reporting new or innovative treatment techniques, and the treatment
status of the seller of purchased water
2;
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ADDITIONAL INFORMATION ABOUT PUBLIC WATER SYSTEMS:
Additional information is required to be reported as it is applicable for every public water
system. States have 60 days from the end of each quarter to report to EPA any violations, enforcement
actions, variances, or milestones, and another 30 days to verify and correct this information. For
example, a violation that occurred in the middle of the first quarter of the fiscal year (November) is
available in SDWIS/FED by the beginning of the third quarter (April).
Violation Information (for-each violation): A violation occur-s any time a public water system fails to
comply with Federal standards for safe drinking water. There are three main types of violations:
Maximum Contaminant Level (or MCL) violations (when tests indicate the level of a contaminant in
treated water is above the legal level); Treatment Technique violations (the system failed to treat the
water in the way prescribed by EPA to ensure its safety); and Monitoring and Reporting Violations
(the system failed to test for certain contaminants on the schedule required by EPA or the State or to
report results in a timely fashion),
• A violation ID number which uniquely identifies the violation
• Which contaminant the violation is for
• What type of violation has occurred (MCL, treatment technique, or monitoring and reporting)
• The time period during which the violation occurred
• The date the state or EPA region became aware of the violation (for certain contaminants)
• For monitoring violations, whether it is a major or minor violation, depending on the
contaminant and the number of samples taken
Enforcement Information (for each formal enforcement action'): Enforcement actions occur when
states or EPA take actions to ensure systems that incur violations return to compliance
• An enforcement ID number which uniquely identifies the enforcement action
• Information to link the enforcement action to a specific violation(s)
• The type of enforcement action taken (e.g., administrative order, boil water order, etc.)
• The date the enforcement action was taken
• An indication that the water system has returned to compliance (for many violations)
Variance and Exemption data (Tor each Variance and Exemption): A variance or exemption is state or
EPA permission authorized under SDWA not to meet a certain water quality standard. Few states or
regions grant variances or exemptions. The water system must prove that: 1) it cannot meet the MCL
or treatment technique, even while using the best available treatment method, because of the
characteristics of the untreated water or other compelling reasons (including economic factors),
and, 2) the variance or exemption 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. The state or EPA
must set a schedule under which the water system will no longer need the exemption because it will
then be in compliance with applicable standards.
• The variance and exemption ID number which uniquely identifies the variance or exemption
• The contaminant or standard the variance and exemption applies to (e.g., a system may have a
variance from the atrazine MCL or a requirement to install filtration)
• When the variance or exemption went into effect, when it expires, and what the schedule is
for implementation (if applicable) of the variance or exemption
• The alternate process or revised MCL that is in effect instead of the usual standard and the
reason for the variation or exemption
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Milestones for Lead and Copper and Surface Water Treatment Rules: Certain milestone events are
required for EPA 's Lead and Copper Rule and Surface Water Treatment Rule (both are regulations
which require the installation of treatment under certain circumstances).
• What the milestone is (e.g. successful completion of a corrosion control treatment study)
• The date of the milestone
• Description of the milestone requirement or status
Under the Lead and Copper rule, systems may also be required to report additional information if they
exceed EPA's action level for these contaminants.
Unregulated Monitoring Data
• Some public water systems are required to report the existence of and levels of contaminants
that are not currently regulated by EPA (to assist in future regulatory decisions)
OPTIONAL INFORMATION IN SDWIS/FED:
Much more information can be stored in SDWIS/FED. Generally, because it is not required, it
is not widely reported by all states or EPA regions. Depending on the state or region reporting a
specific piece of optional data, this information may be nearly complete or practically empty for every
water system in the database. Here are some examples of the type of information SDWIS/FED may
contain for public water systems:
• Information on all water sources, including: the local name of the source (e.g., Red River,
Well #5); geographic identifiers (e.g., USGS hydrological unit codes, the river reach the
source water is on); type of water (e.g., surface water, ground water, ground water under the
direct influence of surface water, purchased water) supplied by the source*; the ratio of each
type of source water used by the system (e.g., sixty percent ground water and forty percent
surface water); the availability of each source (e.g., permanent, year-round, seasonal, or used
only in an emergency); some specific construction information on wells used by the system
(e.g., depth of the screen, the well covering, the pump capacity, etc.); and latitude and
longitude information (and other data) which will be required (see page 2) but are not
currently required
* required for at least one source and all surface water sources and optional for all other sources
• Water production information (for the entire water system and each individual treatment:
plant). At the system level: total design capacity, emergency capacity, and total storage
capacity. At the plant level: the specific capacity for the plant, and the date the plant was
constructed and put into operation.
FOR MORE IN FORMA TION ON:
* Individual Public Water Systems: Violations and enforcement information for every water
system is available on the Internet at: http://www. epa. gov/enviro/html/sdwis/sdwis ov. html
SDWIS/FED: To request specific information from SDWIS/FED, contact EPA 's Freedom Of
Information Act (FOIA) Office at (202) 260-4048, or write to: Freedom of Information Office
US EPA, 401 MSt. SW (1105), Washington, DC 20460.
• Drinking Water: More information on the Safe Drinking Water Act is available through
EPA's Office of Ground Water and Drinking Water web site, http://www. ena. zov/safewater.
or by calling EPA's Safe Drinking Water Hotline, (800) 426-4791.
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