United States
Environmental Protection
Agency
User Guide to the Drinking Water Mapping
Application to Protect Source Waters (DWMAPS)
Snow law report Clear qoety
r
Drinking Water Mapping Application to Protect Source Waters (DWMAPS)
Where Do I Start?
* Who Supplies My Water?
Where Are Potential Sources of Contamination?
A Is My Waterway Polluted?
What Can I Do About II?
© Complete User Guide
I I < s I \ I I s
Layer List
0 Tun Off Al Layen
* O '"
» n ' "C*»
> D
[~1 Pipelifwi
Q CrxkOI B
D
D
D
Traniponation
^oane. FAO NOAA USGS EP>*
Welcome to DWMAPS! This tool is designed to map and identify
Watersheds important to drinking water supply and public water suppliers for your area
Potential sources of contamination
Status of waters under the Clean Water Act (e.g., waters listed as impaired for a given pollutant)
Partnerships and watershed projects in your area
The homepage of DWMAPS describes the search functions available in the map. Each question in the "Where
Do I Start?" window corresponds with a toolbar (upper left symbols) you can use to search the map for data.
Browse Sections 1 through 4 below for more information on how to use these toolbars.
-------
Map Anatomy
I Shows results of previous search
'* r * *
Who supplies my water?
What are some potential sources of
contamination?
Is my water polluted?
What can I do about it?
U*,,:»,. Rott.... »1
ssl6*4 v.'->** «««.*«
.. .** /
-
ARIZONA
^tetw . NFW MEXICO
^ -^ »»«; MjllK,,.o ^,_,,,,. ^^/'
""
I iU.HIt
.tMt '
\
Io,,«on »-«« " " "
ii Gravrw WiMt Souicx m V/H«HKO O
Partnerships ana Projects
CWA313Qran»
Sourc* Water Collabo>anv*i
Gsology jnO Land US*
Basic elements of DWMAPS are outlined here.
The map contains analytic toolbars (upper left) as well as a layer control board for
activating water-related and other data overlays. See the map Glossary and Metadata for
additional information on layers.
Use the location search bar in the upper right corner to zoom to a specific location of
interest.
Click the legend to the right of the location search bar to define map symbols.
To home the home map setting, select the basemap icon and choose between 12 different
options in the basemap gallery (e.g., topographic, satellite, streetmaps)
The button "clear query" clears all search terms the user has input
The button "show last report" allows you to more easily see map results. Map results are
both mapped data and report summaries of those data. You may close out of a summary
report to view mapped results more easily; to retrieve the report, click "show last report."
-------
1 "Who supplies my water?" toolbar
Summary
Use this toolbar to learn about water systems serving your county. Which systems serve your
home or workplace? Have any of these systems violated health-based standards for
contaminants under the Safe Drinking Water Act?
You can also use this toolbar to identify watersheds that are important to drinking water supply.
Locate watersheds in your area where restoration activities can help safeguard drinking water.
Step-by-Step
1. To Enter the tool, select the water drop icon, or click on the question, "Who supplies my water?" in
the DWMAPS homepage.
2. The map will display a dropdown menu asking you to choose a location:
a. "Select a location": enter a map coordinate in the search window, or select "click on the
map" (you will be asked to pick a point on the map after completing the search window)
b. "Draw an area": draw a polygon on the map. Click on map to draw polygon edges.
c. "Select a county": select a state and county of search (dropdown menu).
3. Select either "Watershed1 Information" or "Public Water Systems" within search window to find the
following information:
"Watershed Information"
"Public Water Systems"
"Select a location"
Information about the WATERSHED
surrounding point selected
Information about PWSs serving the
COUNTY surrounding point selected
"Draw an area"
Information about ALL WATERSHEDS
intersecting the polygon selected
Information about PWSs serving ANY
COUNTY intersecting the polygon selected
"Select a county"
Results for ALL WATERSHEDS intersecting
county selected
Information about PWSs serving the
COUNTY you selected
If you selected "Watershed information"
DWMAPS will provide a results table with the following information about selected watersheds
Watershed name
% of watershed covered by a source water protection area
Surface water intake density: number of intakes (surface water facilities) withdrawing drinking
water in the watershed
Ground water well density: number of wells (ground water facilities withdrawing drinking water
from an aquifer) per watershed. Note: this information does not reflect aquifer well density.
1 "Watershed" as used in DWMAPS and this User Guide is a shorthand term for HUC12, a hydrologic unit
designating a smaller drainage area within a watershed.
-------
Click on column headings in the results table to sort results by column value (e.g., rank
watersheds by % covered by source water protection area)
Each watershed link contains a link to a full watershed profile under EPA's "Surf Your
Watershed" database. The link shows:
The larger hydrologic area (HUC8) containing your watershed
Water quality monitoring information from USGS and state program data
Watershed restoration groups working in the watershed
1 Watershed impairments, stream flow statistics, relevant scientific studies, and much
more.
Watershed names in the links and DWMAPS table may not match. Don't worry! The
watersheds identified in DWMAPS are smaller subdivisions of the larger hydrologic units
reflected in "Surf Your Watershed" links. Names may differ.
If you selected "Public Water Systems"
EPA's Safe Drinking Water Information System (SDWIS) keeps track of the counties served by Public
Water Systems. Choosing a location and selecting "Public Water Systems" provides a list of Public Water
Systems serving your county. Please note: DWMAPS lists water system serving your county, but these
are not necessarily located near you. Water systems often do not serve the same county where they
are located. For example, much of Los Angeles' water comes from Northern CA and the Sierra Nevada.
DWMAPS will provide a results table with the following information about water systems serving your
county(ies) of search:
Public water system name and database ID for EPA SDWIS
County served by Public Water System
Quick Tips
Click on column headings in the results table to sort results by system attributes (system
size, name, etc.)
Each system link contains a link to a full system profile under EPA'S Envirofacts site. The
profile shows:
Any recent health-based violations of the Safe Drinking Water Act
1 Dates when system active
Permitting, enforcement, and legal compliance information
Much more!
Data is not available at a finer scale than the county level
-------
2 "Where are potential sources of
contamination?" toolbar
Summary
Use this toolbar to learn about potential sources of contamination upstream of your area of
interest. How many Superfund sites are within 3 miles of a well? Are there any wastewater
treatment plants located upstream of your local lake? Where are the industries discharging
pollutants within 24 hours travel time of a municipal water supply?
Step-by-Step
1. To Enter the tool, select the pollution plume icon, or the question, "Where are potential sources of
contamination?" in the DWMAPS homepage.
2. Select "find potential sources of contamination"
3. Enter a known coordinate in the "latitude" and "longitude" fields. If a coordinate is not known,
select "Click on the map." Before clicking on the map, select the following search commands:
4. Specify your area of search. The map will display the following information based on your selection:
"Find potential sources of contamination"
"withinjiours upstream"
Information about potential sources of contamination within the catchments (small
drainage area) that are located within _ hours of your point, by average streamflow
,2
"within_miles upstream"
Information about potential sources of contamination within the catchments (small
drainage area) that are located within _ miles of your point, along the stream network
"within mile buffer"
Information about potential sources of contamination within ajnile radius of your point
5. Specify your point sources of interest. Search "any facility" (results show facilities of any type) or
choose any combination of the following (see glossary for more detail).
CERCLA
CSO
NPDES
RCRA
TRI
TSCA
6. Press "OK"
2 Time of contaminant travel estimations are based on average streamflow rates. Uses service from the National
Hydrography Dataset (NHDPIus)
-------
Choose your layers.
While running your search, the map will automatically activate all point source layers. In
order to improve visibility of point sources, deactivate/activate layers one at a time.
There's more than meets the eye!
Click on any point or shape in any layer to find more information on that features. Click on
point source features to view a full profile for each facility through EPA's Enforcement and
Compliance History Online (ECHO) database, which shows:
Satellite image of facility
Address and permits for that facility
Any recent violation/noncompliance of permit limits
Pollutants discharged from facility*
Demographic information about nearby census tracts (age, education level, average
income, household size)
Much more!
If the facility is registered under EPA's Toxics Release Inventory (TRI). TRI facilities
Additional notes
Getting downstream results? Some map results for "hours upstream" searches will show point sources
slightly downstream of your selected location. This is because "hours upstream" results are based on
catchments, or small drainage areas, tied to the stream network. The map will identify all point sources
within catchments upstream of, and surrounding, your location. Some results may lie within the
downstream portion of the catchment surrounding your location.
24 hours not enough? The maximum search range in the map is set at 24 hours (time of travel), 15 miles
(distance upstream), and 25 miles (radius). Increasing the search range would compromise map
performance. If you wish to query, for example, 30 hours upstream of a given point, run two separate
searches for 1) 24 hours upstream and 2) 6 hours upstream of the point furthest upstream from search
(1).
What about nonpoint and other data? Only certain point sources are searchable through the "Where
are potential sources of contamination?" toolbar. Use the layer menu to learn more about nonpoint
sources of contamination (e.g., manure and fertilizer loading per county) and linear data like pipelines
and hazardous material transport routes.
-------
3 "Is my waterway polluted?" toolbar
Summary
The Clean Water Act (CWA) requires states to identify rivers, streams, and lakes that are "impaired," or
too polluted to support activities like recreation, fishing, and public water supply. Which water bodies in
your state are considered "impaired"? Are these waters used for public water supply? What pollution
issues are causing these impairments?
The CWA also requires facilities like industries discharging pollutants into water bodies to obtain permits
under the National Pollutant Discharge Elimination System (NDPES). DWMAPS can help you locate these
facilities and find out what pollutantsand how muchthey discharge.
This tool is designed to help you use the CWA to protect your source of drinking water. Refer to the
Clean Water Act-Safe Drinking Water Act Coordination toolkit for more information.
Step-by-Step
1. Select "Clean Water Act"
2. Decide what type of CWA information you're looking for
i. Select "Assessed waters" to highlight all rivers, streams, and other water bodies that have
been assessed by states.
ii. Select "Designated uses" to highlight all rivers, streams, and other water bodies that are
designated to support an activity/use you're interested in (e.g., public water supply,
recreation, aesthetic value, etc.). Select uses from dropdown menu.3
iii. Select "Impaired waters" to highlight all rivers, streams, and other water bodies that a state
has listed as "impaired." Select a pollution issue from the dropdown menu to show
impairments caused by that issue. For example, choosing "nutrients" from the dropdown
menu will show only water bodies that are impaired due to high nutrient levels.
iv. Select "TMDLs" to highlight all rivers, streams, and other water bodies that have Total
Maximum Daily Loads for a given pollutant. Select a pollutant from the dropdown menu.
v. Select NPDES permitted dischargers to highlight point sources discharging a specific
pollutant. Select your pollutant of interest from dropdown menuthe map will return
facilities permitted to discharge that substance.
3. Press "OK"
3 Don't see your designated use? EPA maintains a standardized list of designated use categories, but
states often individually develop their own designated use categories. If your state applies specific
designated use definitions, you may not find those uses in the DWMAPS dropdown menu for designated
uses. They will be contained in the "Other" category in DWMAPS.
-------
The map results will highlight waters or NPDES facilities that match your search terms within your view
extent.4 The map will also automatically activate the full map layer of interest (impaired waters, TMDLs,
etc. across the country) and highlight drinking water layers in the map. This will allow you to identify
areas where CWA regulatory measures can better protect drinking water. For more information on using
the CWA to protect drinking water, click HERE.
There's more than meets the eye!
IF SEARCHING FOR A WATER BODY: Click on any stream segment, river, or water body on
the map. A pop-up window will show a link to "More info" through EPA's WATERS database,
where you'll find a full profile of each water body including,
Designated use of water body
Impairments in reporting year 2012
Follow-up actions taken
Waterbody history report
Waterbody size and location
IF SEARCHING FOR NPDES DISCHARGERS: Click on any NPDES facility on the map. A pop-up
window will show a link to "More info" through EPA's Enforcement and Compliance History
Online (ECHO) database, where you'll find,
Satellite image of facility
Address and permits for that facility
Any recent violation/noncompliance of permit limits
Pollutants discharged from facility*
Demographic information about nearby census tracts (age, education level, average
income, household size)
Much more!
What about pollution load? To find out the permit limits and annual load of pollution from a
NPDES permitted facility, click on the facility in the map and select "show detailed results"
4 Search results pertain to your view extent. If you pan your screen to a new view extent, click the bottom right
window that reads "Re-run query" for improved results.
-------
4 "What can I do about it?" toolbar
Summary
Through exploring DWMAPS, you can find data to prioritize source water protection activities. The "What
can I do about it?" toolbar helps you take the next step and find or contact nearby watershed groups
that are working to restore local watersheds.
Step-by-Step
1. To Enter the tool, select the icon that looks like a group of people or click on the question, "What
can I do about it?" in the DWMAPS homepage.
2. The map will display a dropdown menu asking you to choose a location:
a. "Select a location": enter a map coordinate or pick a point on the map (you will be asked to
pick a point on the map after completing the search window).
b. "Draw an area"
i. draw a polygon: click on map to draw polygon edges or
ii. draw a circle (a "buffer"): select a mile-radius and click a point on the map to draw a
circle (buffer) around that point.
c. "Select a county": select a state and county of search (dropdown menu).
3. Specify your area of search. The map will display the following information based on your selection:
"What can do about it?'
"look in my watershed"
Information about watershed groups in the watershed surrounding point selected.
"draw an area"
Information about watershed groups in any watershed intersecting the area or buffer
selected.
"within mile buffer"
Information about watershed groups in any watershed intersecting the county selected
(includes statewide groups whose scope includes selected county).
4. Press "OK"
The DWMAPS result table will show two types of watershed projects:
Nonpoint source control projects: projects to manage nonpoint sources of pollution such as
agricultural runoff, funded through EPA's Clean Water Act Section 319 grant program. The results
table shows the following information
State or watershed: scope of project (statewide or specific to a single watershed)
Project title
Project type (e.g., technical assistance, statewide education)
Start date
Completion status
Grant allocation (amount allocated by EPA, not including matching funding by
watershed group/grant applicant)
-------
2. Source Water Collaboratives: partnerships of diverse stakeholders who work together to
implement source water protection projects and education initiatives in states, regions, or
specific watersheds and local communities. The results table shows the following information:
Collaborative name
Collaborative type (scope is local, county-based, or interstate/regional)
To start a new collaborative, or to learn more about actions to protect source water, visit the link at the
bottom of the results table: "Actions to protect source water: http://sourcewatercollaborative.org"
L
Click on column headings in the results table to sort results by column value (e.g., rank
projects by grant allocation, project type)
Links in the results table lead to more information on watershed groups, including
319 projects
Project manager, phone number
Whether/not project has pollutant load data
Comments on project schedule
Detailed grant budget
Project overview
HUCIZs and HUCSs covered by project
Dainage area pollutants
Source Water Collaboratives
Contact information
Description of collaborative scope and formation
Member list
Overview of drinking water concerns
Past actions (strategies) and results
Watershed groups may not be working at the exact point location you specify. Information
on watershed groups is indexed at the watershed level and at the state level.
Office of Water (4606M) EPA 816-B-16-001 January 2016 www.epa.gov/sourcewaterprotection/dwmaps
------- |