United States
           Environmental Protection
           Agency
Office of Water
(4503F)
Washington, DC 20460
EPA-841-R-97-010
September 1997
£EPA     The Index of Watershed Indicators

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                                                  INDEX OF WA TERSHEDINDICA TORS

Twenty-five years ago the 92nd Congress took a bold step to maintain and restore our Nation's waters by enacting the Federal Water Pollution Control Act, now known
popularly as the Clean Water Act.  We can be proud of the outstanding progress the Nation has made in improving water quality in the last century. Tins progress is the result
of cooperative efforts by Federal, State, Tribal, regional, and local governments, volunteers, and people in private enterprise.  This progress is all the more remarkable
considering that our economy and population both grew rapidly over the period.

We must maintain the strong foundation of basic national water protection programs that we have worked so hard to put in place and which has  brought about much of the
progress to date.  But, if we are to maintain steady progress toward our goals of clean water and safe drinking water, we must increase our capacity to identify water
quality problem areas and design tailored programs to address the causes of problems that differ from place to place.  As part of this effort, we are working with all
our monitoring partners to upgrade and streamline the water monitoring program and to improve the process of identifying impaired waters in each State.  Perhaps most
important, we must develop new tools to describe the overall health of aquatic systems on a watershed basis. As John Wesley Powell defined it, a watershed is an "area of
land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where,  as humans settled, simple logic demanded
that they become part of the community."

This Index of Watershed Indicators (the Index) is the first national effort to organize nationally available aquatic resource information and present it at the watershed level.
The Index is built on 15  different water resource indicators using information from a variety of public and private partners. Drawing on these indicators, the Index provides a
description of the condition and vulnerability of each of the 2,111 watersheds in the continental United States. We will include Alaska and Hawaii later.

By  organizing water resource information at a watershed scale, we can inform and improve the dialogue among watershed managers, water quality professionals, and citizens
on the condition of our watersheds and the actions needed to protect or restore water quality.  To enlarge this dialogue and tap the energy and creativity of a broader segment
of the populace, watershed information needs to be widely available.  To meet this goal, we designed the Index so that both national databases and the descriptions of each
watershed are available on the Internet. Using the  Index, we can inform and empower citizens to better understand conditions in the watershed where they live and to be part
of the solution of preserving or restoring healthy aquatic systems.

The Index is the result of a cooperative, multi-year process involving U. S. EPA and many public and private agencies and organizations. I want to express my sincere
appreciation to everyone who contributed to this challenging, ground-breaking effort. I especially want to commend States that have made the vital commitment to strong
water quality monitoring programs. A number of these States stepped forward with detailed monitoring data, knowing that their data would show problems that would not be
apparent in States with more limited monitoring programs.

Finally, it is important to note that this first effort to characterize watershed condition and vulnerability can and will be improved. Some indicators will be revised as data are
improved. New indicators such as  groundwater will be added as better data are developed. In addition, the Index is an aggregation of data from national databases, not a
detailed, on-the-ground assessment of each watershed. U.S. EPA, States, Tribes and others have more detailed information in specific places  to help watershed managers
design more detailed watershed assessments.  Much of this information is available on the Internet at http://wwvv.epa.gov/surf and I urge others  to link their  information to
this program to provide an electronic index of comprehensive water quality data.

I am confident that, working together to better understand the condition of aquatic resources on a watershed basis, we can all look forward to  continued steady progress in
improving water quality.

                                                                 Bob Perciasepe
                                                                 Assistant Administrator for Water
                                                                 U.S. Environmental Protection Agency
                                                                                                                                                    Page 2

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                                                  Table of Contents

o      Introduction By U.S. EPA Assistant Administrator for Water Robert Perciasepe	  2
o      The Process to Produce the Index of Watershed Indicators  	  4

The Maps:
     0.    National Watershed Characterization	6
     1.    Assessed Rivers Meeting All Designated Uses Set in State/Tribal Water Quality Standards 19947 1996	  8
     2.    Fish and Wildlife Consumption Advisories 1995	  10
     3.    Indicators of Source Water Condition for Drinking Water Systems 1990 - 1996  	  12
     4.    Contaminated Sediments 1980 - 1993	14
     5.    Ambient Water Quality Data - Four Toxic Pollutants 1990 - 1995	  16
     6.    Ambient Water Quality Data - Four Conventional Pollutants  1990-1995	  18
     7.    Wetland Loss Index  1982 - 1992;  1780 - 1980    	20
     8.    Aquatic/Wetland Species at Risk 1996	22
     9.    Pollutant Loads Discharged Above Permitted Limits - Toxic Pollutants  1995    	24
     10.   Pollutant Loads Discharged Above Permitted Limits - Conventional Pollutants  1995	  26
     11.   Urban Runoff Potential 1990    	28
     12.   Index of Agricultural Runoff Potential 1990 - 1995  	      	30
     13.   Population Change 1980-1990    	32
     14.   Hydrologic Modification Caused by Dams 1995 - 1996	      	  34
     15.   Estuarine Pollution Susceptibility Index 1989 - 1991  	36
o    Index of Watershed Indicators Phase 2 - Plans for the Future	       	39

Supplemental Maps:
     3a.   Rivers and Lakes Supporting Drinking Water Uses 1994 - 1996	40
     3b.   Surrogates of Source Water Condition 1991 - 1996	      	   42
     3c.   Occurrence of Chemicals in Surface and Ground Waters that are Regulated in Drinking Water 1990-1995	44
     7a.   Wetland Loss Measured by the Natural Resources Inventory 1982-1992 .      	46
     7b.   Wetland Loss Measured by the National Wetlands Inventory 1780 - 1980s	48
     12a.  Potential Pesticide Runoff from Farm Fields 1990 - 1995  	50
     12b.  Potential Nitrogen Runoff from Farm Fields 1990 - 1995	52
     12c.  Sediment Delivery to Rivers and Streams from Cropland and Pastureland 1990 - 1995	54

o   Contacts for Further Information	56


                                                                                                                         Page 3

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The Process to Produce the Index of Watershed Indicators
The U. S. Environmental Protection Agency's Office of Water and its many public and private partners have developed this Index of Watershed Indicators as a national
presentation of aquatic resource health.  The Index is designed to collect, organize, and evaluate multiple sources of environmental information on a watershed basis.  A
watershed is an area of land, bounded by ridge lines, that catches rain and snow and drains into a marsh, stream, river, lake, estuary, or groundwater aquifer.  There can be
many types of waters in a watershed, including lakes, rivers, estuaries, wetlands, streams, aquifers, and ground water recharge areas as well as the surrounding landscape
and activities which affect the waters  It is possible to delineate watersheds in a variety of sizes ranging from the Mississippi River watershed, which encompasses most
of the central United States, to watersheds draining small, tributary streams.

Watershed delineation:  For the purposes of this project, watersheds are delineated using the  U.S. Geological Survey's 8-digit Cataloguing Unit (CU), which is the
smallest consistent national watershed size. Using this system, the United States is divided into 2,149 watersheds which range in size according to the area that the watei
drains,  (Note that in some cases, States  and Tribes delineate smaller or differently configured watersheds for their own purposes.) This initial product, which is Phase 1
of the Index of Watershed Indicators, shows only the 2,111  watersheds in the continental United  States. Alaska and Hawaii will be included in Phase 2, which begins
upon publication of Phase 1 in July 1997.

 Many of the remaining water quality problems in the United States can be addressed most effectively along watershed lines. The U. S. EPA, States, Tribes, and other
 agencies are all moving toward a watershed-based approach to environmental protection. This entails integrating traditional program areas (e.g., flood control,
 wastewater, and land use) and improving coordination between local, State, Tribal, regional, national and private partners. A major benefit of the watershed  approach is
 that attention is placed on the achievement of measurable environmental results.

 Index objectives: The Index of Watershed Indicators has four primary objectives.  These are to:

 •   characterize the condition and  vulnerability to pollution of the watersheds of the United States;
 •   provide the basis for dialogue between water quality managers;
 •   empower citizens to learn more about their watersheds and work to protect them; and
 •   measure progress toward EPA's goal that all watersheds will be healthy and productive places.

  The indicators:  In order to meet these objectives, U. S. EPA and its partners selected 15 separate water quality indicators. Together these indicators were used to
  create an index of water quality on a watershed basis.  The  data behind each of the 15 indicators come from a variety of sources such as States, Tribes, U. S. EPA, U.S.
  Census Bureau, the Natural Resources Conservation Service of the U.S. Department of Agriculture, National Oceanic and Atmospheric Administration, The Nature
  Conservancy, U.S. Army Corps of Engineers, U.S. Geological Survey, U.S. Fish and Wildlife Service, and the many public and private individuals who contribute data to
  the national databases that  these organizations maintain.

 The 15 data layers  of the Index of Watershed Indicators consist of two categories of information: Condition and Vulnerability. The condition data layers (maps 1-7) are
 designed to show existing water quality  across the country.  The vulnerability data layers (maps  8-15) are designed to indicate where discharges and other stressors
 impact the watershed and could, depending on the natural and manmade factors present in the watershed, cause future problems to occur.  Note that several indicators
 used in the Index of Watershed Indicators characterization consist of indices combining more than one kind of data. For three indicators, more detail is provided in
 supplemental maps at the end of this report.

                                                                                                                                                 Page  4

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 The following indicators are used to characterize condition:
 1)  Assessed Rivers Meeting All Designated Uses Set in State/Tribal Water Quality Standards
 2)  Fish and Wildlife Consumption Advisories
 3)  Indicators of Source Water Condition for Drinking Water Systems
 4)  Contaminated Sediments
 5)  Ambient Water Quality Data - Four Toxic Pollutants
 6)  Ambient Water Quality Data - Four Conventional Pollutants, and
 7)  Wetland Loss Index

 The following indicators are used to characterize vulnerability:
 8)  Aquatic/Wetland Species at Risk
 9)  Pollutant Loads Discharged Above Permitted Limits - Toxic Pollutants
 10) Pollutant Loads Discharged Above Permitted Limits - Conventional Pollutants
 11) Urban Runoff Potential
 12) Index of Agricultural Runoff Potential
 13) Population Change
 14) Hydrologic Modification Caused by Dams
 15) Estuarine Pollution Susceptibility Index

 The maps of each indicator show where general patterns in water quality exist and where we are missing data. Each data layer map also includes important information
 such as why the data layer is important, how to access the background data we used, who to contact for more information, and descriptions of data quality.

 Data quality:  Data layers used to characterize aquatic resource health must be of adequate data quality. The data layers represented in this report contain measurements
 of varying quality and were originally collected for other purposes.  These measurements differ in precision, accuracy, statistical representativeness, and completeness.
 Data collection methods and purpose, quality control and age of data vary. This national report uses data from several agencies who have undertaken data quality
 assessments for their original purposes.  The data quality of each data layer as it is used in the  Index of Watershed Indicators is specifically identified in this report. Data
 of mixed quality are included for two reasons: (1) the data layer describes an important, if as yet imperfect, way to measure a nationwide objective, and (2) efforts are
 underway to improve data layer measurements in future reports.  Each watershed profile available on Internet and the data summaries below show the level of data quality
 for the national data set using the following  descriptions:

 •   Data consistent/sufficient data collected
 •   Data somewhat consistent/additional data needed
    Data need to be much more consistent/much additional data needed

 Index improvements:  Although the Index of Watershed Indicators is still in its first phase  of development, beneficial impacts are already apparent.  For instance, the
 Index of Watershed Indicators has significantly improved many data sets supporting the characterization. Agencies examining the Index of Watershed Indicators data are
 building closer relationships as they work to integrate these diverse data sets.  In addition, other agencies and organizations are using the Index of Watershed Indicators
 framework to conduct their own,  more detailed assessments of water quality on a watershed basis (e.g., New England States, U. S. EPA Region 3, and the Natural
 Resources Conservation Service). In addition, the Index of Watershed  Indicators is expanding our capacity to communicate with our partners, review and comment on
 data and its significance, and disseminate information to water quality managers and the public, particularly using the Internet and electronic information transfers.

U.S. EPA and its partners  will be continuing to build upon and improve this index.  As new data becomes available, the data layer maps and composite index will be
updated on U.S.  EPA's "Surf Your Watershed" website found at: http://www.epa.gov/surf

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                                             National \\atershed Characterization
Anahsis of Alaska and
Hawaii reserved for Plase2.
 Watershed Qassificaiion
   ^ Better Water Quality- Low Vulnerability
 Hi Better Water Quality - High Vulnerability
 I   I Less Serious Water Quality Problems - Lo\v Vulnerability
 [   I  Less Serious Water Quality Problems -High Vulnerability
 L  _|  IVbre Serious Water Quality Problems - Lo\v Vulnerabilits
 ff§ IVfare Serious Water Qualit> Problems - High Vulnerabilitx
 ;~~~1 Ddta Sufficiency Threshold Not Met
Index of Watershed
      Indicators
     http:/A\wv epa gov/surf
                                                                                                                         June "
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 Importance of the National Watershed Characterization

 The Index of Watershed Indicators characterizes the condition and
 vulnerability of aquatic systems in each of the 2,111 watersheds in the
 continental U.S. This involves an assessment of condition, vulnerability,
 and data sufficiency.

 The approach is simple. First, indicators of the condition of the watershed
 are scored and assigned to one of three categories: better water quality, water
 quality with less serious problems, and water quality with more serious
 problems.  Second, indicators of vulnerability are scored to create two
 characterizations of vulnerability: high and low. These two sets of indicators
 are then combined to create the following spectrum:

 1.    Watersheds with better water quality and lower vulnerability to stressors
      such as pollutant loadings
 2.    Watersheds with better water quality and higher vulnerability to stressors
      such as pollutant loadings
 3.    Watersheds with less  serious water quality problems and lower
      vulnerability to stressors such as pollutant loadings
 4.    Watersheds with less  serious water quality problems and higher
      vulnerability to stressors such as pollutant loadings
 5.    Watersheds with more serious water quality problems and lower
      vulnerability to stressors such as pollutant loadings
 6.    Watersheds with more serious water quality problems and higher
      vulnerability to stressors such as pollutant loadings
 7.    Watersheds for which insufficient data exists to make  an assertion of
      condition or vulnerability

 The Index of Watershed Indicators shows that about:
 •    16% of the watersheds in the  country have better water quality and of
      these, one in eight have high vulnerability;
 •    36% have some water quality problems and of these, about one in ten these
      high vulnerability;
 »    21% have more serious water quality problems with one in ten of these
      exhibiting high vulnerability;  and,
 •    27% of the watersheds in the continental United  States do not have enough
      information on the component indicators to make an overall assessment.

The information provided by the Index of Watershed Indicators will help focus
the  attention of water quality managers and decision makers on areas with
problems in need of restoration, on  areas with good water quality in need of
protection, and on areas where additional data is needed. When looking at the
results of the IWI, however, it is important to note that the strength of monitoring
programs varies across the country. Areas with strong monitoring programs may
show more problems than those with weaker programs. Good monitoring
provides valuable environmental information and should be rewarded.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed" at:
 Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Data Sufficiency Thresholds
Data sufficiency thresholds levels were set for data in both the condition and
vulnerability categories.  These threshold levels ensure that sufficient data
exists to make a valid judgement of aquatic resource health. For the
condition data layers, each watershed must have information for at least four
out of seven data sets or they are are  considered to have "Insufficient Data."
A similar data sufficiency screen is applied to vulnerability data, where at
least six of the eight indicators are needed.

Notes on Interpreting this Information
• This map combines 15 disparate data layers as listed above. All of the notes
   listed for the component data layers must be taken into account when using
   this map.
» State water quality assessments (305(b) designated use data) were given
   special consideration.  First, when  State 305(b) data were present,  this data
   layer was weighted six times more heavily than other data layers. Wliere they
   were absent, the data from other condition indicators were weighted more
   heavily to compensate for this missing information

Plans  to Improve this Data Layer
As the  data for each of the component data layers is improved, the overall Index
of Watershed Indicators map will also  improve. U.S. EPA will continue to work
on revising the scoring system to ensure  it reflects aquatic resource condition and
vulnerability as accurately as possible.

For More Information Contact:
Individual Contact
Charles Spooner,  202 260-1314
E-mail: Spooner.Charles@epamail.epa.gov
                                                                                                                                                  Page  7

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                                1. Assessed Rivers Meeting All Designated Uses
                                  Set in State/Tribal Water Quality Standards
                                                     1994/1996
 Analysis of Alaska and
 I la\\a i reserved tor Phase 2
 Percent of Assessed Watershed Rivers
 Meeting All Designated Uses:
 I   I 80 -100% Meeting All Uses
 |   | 50 - 79% Meeting All Uses
 |   [ 20 - 49% Meeting All Uses
JH| < 20% Meeting All Uses
H H Insufficient IWI Data
  Index of Watershed
       Indicators
Sources: U.S. Environmental Protection Agency
     National Water Quality Invert ory
                                                                                                        June 27. 1 597
                                                                                                                n 4.93.1*13!

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Map 1
Importance of Assessed Rivers Meeting All Designated
Uses  Set in State/Tribal Water Quality Standards

States and Tribes adopt water quality standards that include designated uses and
criteria to protect those uses.  Uses typically include drinking water supplies,
aquatic life use support, fish and shellfish consumption, primary and secondary
contact recreation (e.g., swimming and boating), and agriculture. States and
Tribes describe water quality in terms of a waterbody either fully supporting,
partially supporting, or not supporting the designated use and report this
information biennially to U.S. EPA which then compiles it in the National
Water  Quality Inventory Report to Congress (305(b)) Report.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed"
at:
. Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Data  Sufficiency Thresholds
State and Tribal assessments were considered sufficient to characterize the
condition of a watershed if more than 20% of the total perennial stream miles
(as expressed by Reach File 3 (RF3)) were assessed. RF3 is a computer
database showing the location and flow direction of surface waters compiled
from maps produced by the U.S. Geological Survey. 20% approximates the
lower 25th percentile of assessed watershed miles for the entire country.  Since
RF3 total water estimates are not available for U.S. EPA Region 10 States (AK,
ID, OR, WA), all watershed data were retained for these watersheds.  Section
305(b) data from the Delaware River Basin Commission and the Ohio River
Valley Sanitation Commission were used to complement State coverage of those
two rivers without applying the 20% test.

Notes on Interpreting this Information:
•       Data Somewhat Consistent/Additional Data Needed
        Nationally, additional data are needed in many places. Reported data
        are based on National guidelines issued from U.S. EPA, but may vary
       from  place to place due to different water quality standards and
        methods.  See  "Plans to Update this Data Layer" for details.
•       States and Tribes do not have identical water quality standards or
        identical methods or criteria to assess their waters so data may not be
        consistent.
•       Most States and Tribes cannot assess all of their waters during each
        two-year reporting period, and they may modify techniques used or
        assess different waters every two years.
•       Most monitoring undertaken by States and Tribes is focused on rivers.
        lakes and estuaries with suspected or identified pollution problems
        Assessments based on this type of monitoring may not be representative
        of the whole watershed and may overestimate the degree of concern.

Plans to Improve this Data  Layer
U.S. EPA has several initiatives underway to improve the quality of the 305(b)
data,
•       U.S. EPA is working with States, Tribes, other federal agencies, and
        other partners to develop monitoring and assessment approaches that
        will improve state-to-state consistency in reporting.
•       U.S. EPA is also working with its partners to achieve comprehensive
        coverage of the waters in  the nation  in the 305(b) report, and include
        annual electronic updates  of key data elements.
•       This indicator will be updated using the 1996 and subsequent database
        updates as they become available.

For More Information  Contact:
Database Owner:
US. EPA, Office of Wetlands, Ocean and Watersheds
Individual Contact:
Charles Spooner
E-mail: Spooner.Charles@epamail.epa.gov
Phone: (202)260-1314

Data Source:
1. National Water Quality Inventory: 1994 Report to Congress
        U.S. Environmental Protection Agency, Office of Water Washington,
        D.C. December 1995. EPA 841-R-95-005,
2. National Assessment Database
        U.S. Environmental Protection Agency, Office of Water, 1994
  Waterbody System Data
        State of Georgia,  1996

Additional Information
For more information on specific State 305(b) reports contact U S,  EPA's Barry
Burgan at Burgan.Barry@epamail.epa.gov or (202) 260-7060
                                                               Page  9

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                                 2. Fish and Wildlife Consumption Advisories
                                                         1995
            VVJ
Analysis of Alaska and
Hawaii reserved for Ptese 2
Watershed Classification
[   ] Monitored with No Active Advisory
j   I One or More Advisories Recommending Limits on Fish Consumption
|    | One or More Advisories Recommending No Fish Consumption
I    I No Recorded Monitoring and No Advisories
  Index of Watershed
        Indicators
Souices U.S. Emiroumental Protection Agency
          l Listing of Fish & Wildlife
.lune VI 1 9)7

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 Map 2
 Importance of Fish and Wildlife Consumption Advisories

 Fish consumption advisories are a good indicator of the condition of a
 watershed because they can represent bioaccumulation of toxic substances
 in fish and shellfish.  Bioaccumulation is the process by which fish
 accumulate pollutants in their tissues by eating smaller organisms already
 contaminated with the pollutant.  Pollutants can also enter fish and shellfish
 tissue directly from the surrounding water through their gills and skin.
 These pollutants cause fish and shellfish to be unsafe for human
 consumption.

 States monitor fish to determine whether levels of contamination in fish
 tissue pose a threat to the health of the people who eat them. Where fish
 contamination levels exceed safe levels, States often issue advisories to the
 public recommending some limitation on fish consumption (generally
 restrictions on the number of meals over a period of time or the fish weight
 consumed over a period of time) or no consumption offish at all.
 Advisories may also target a specific subpopulation at risk such as children,
 pregnant women, and nursing mothers.

 Access to Detailed Data
 Access to detailed  data for each data layer is available through "Surf Your
 Watershed" at: . Click on the data
 layer of interest to  find documentation and FTP (File Transfer Protocol)
 addresses.

 You can also access the National Listing of Fish & Wildlife Consumption
 Advisories database on at http://www.epa.gov/OST/fishadvice/
Data Sufficiency Thresholds
One smaller waterbody under a fish consumption advisory in a watershed is
sufficient to characterize the entire watershed in this analysis.  Similarly,
data showing that monitoring has occurred and the determination has been
made that an advisory is not appropriate is sufficient to characterize a
watershed.
Notes on Interpreting this Information
•      Data Somewhat Consistent/Additional Data Needed
        See "Plans to Improve this Data Layer" for details.
*      Characterizations for cross-boundary watersheds may be made
        due to advisories in only one of the involved States or Tribes,
        regardless of the amount of area covered by that State or Tribe.
•      Fish consumption advisories are issued by State, Tribal, local, and
        federal governments and each uses its own criteria for determining
        when an advisory is warranted.  In addressing these risks,
        advisories may reflect data from many or a few sites, may vary in
        the number and types of contaminants considered,  may apply to
        only certain types ofwaterbodies, and may apply to only certain
        species or sizes offish.
•      Monitoring for fish tissue contamination may be concentrated in
        areas of most intense fishing or  areas suspected of contamination.
•      For the purposes of this characterization nonconsumption
        advisories include those issued for the general public and/or for
        special sub-populations (e.g. pregnant women).

Plans to Improve this Data Layer
This indicator will be updated using 1996 data and subsequent database updates as
they become available. EPA is looking at other sources of data, such as
contaminants in fish tissue, that may more accurately reflect bioaccumulation of
toxic substances in fish and shellfish.

For More Information Contact:
Database Owner:
U.S. EPA Office of Science and Technology
Individual Contact
Jeff Bigler
E-mail: Bigler. Jeff@epamail. epa. gov
Phone: 202-260-1305
Data Source:
National Listing of Fish & Wildlife Consumption Advisories, 1995
U.S. Environmental Protection Agency,  Office of Science and
Technology
                                                                                                                                        Page

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                                    3.  Indicators of Source Water Condition
                                            for Drinking Water Systems
                                                     1990 -1996
Analysis of Alaska ard
Hawaii reserved for Phase 2
Includes Ground and Surface Water Sources
Watershed Classification
|    | No Significant Source Water Impairment Identified
|    | Partial Source Water Impairment Identified
f~| Significant Source Water Impairment Identified
~—| Data Sufficiency Threshold Not Met
  Index of Watershed
       Indicators
Source: U.S. Environmental Protection Agency
                                                June 24, ]

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Map 3
Importance of the Indicators of Source Water Condition for
Drinking Water Systems

The availability of clean and safe drinking water sources for use by drinking water
systems is a good indicator of the watershed's condition.  Water systems are major users
of the water resources and have continual interest in the quantity and quality of their
water supplies.  Impaired source waters prompt corrective actions (including additional
treatment)  by water systems to ensure that the water provided at the tap to consumers
meets all drinking water standards.

Data to characterize the quality of these source waters is not available nationally. No
single data source currently exists to provide an accurate and complete picture of source
water condition. However, using surrogate measures from different data sets can provide
a partial picture of the source water condition. This data layer combines three indicators
to identify if there is evidence in the watershed of: (1) no significant source water
impairment, (2) partial source  water impairment, or (3) significant source water
impairment in the watershed.

The three indicators used to characterize source water condition were a) rivers and lakes
supporting state drinking water designated uses, b) two Safe Drinking Water Information
System (SDWIS) surrogate indicators of source water condition; and, c) the occurrence
of chemicals regulated under the Safe  Drinking Water Act in ambient waters

Although not displayed here, indicators of source water vulnerability provide additional
evidence of the risk to the use of source waters by water systems. Looking at current
source water condition alone provides only a partial picture of source water. Other data
layers may provide an indication of the vulnerability to source waters.  See Map 12,
Index of Agricultural Runoff Potential, for example.

A combined map of source water condition and vulnerability that will include other
indicators of condition and vulnerability will be developed for future phases of the Index
of Watershed Indicators.


Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed" at:
.  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.


Data Sufficiency Thresholds
Data sufficiency thresholds levels were set for the three data sets used to characterize
source water condition (see maps  3a, 3b, and 3c). These threshold levels ensure that
sufficient data exists to make a valid judgement of source water condition.
Notes on Interpreting this Information
•       Data Somewhat Consistent/Additional Data Needed
         See "Plans to Improve this Data Layer" for details.
•       The assignment of community water systems to the specific watershed
         is based in some cases on incomplete locational information and may
         not accurately represent the water system 's source water.
•       The watershed boundaries used in the IWI are bigger and different
         than the source water boundaries for many water systems.
•       Water systems may use water sources that are in more than one
         watershed, a fact that is not captured in the IWI characterization.
•       Some public supplies may use ground water sources from a confined
         aquifer, which may not be representative of the source water condition
         in the watershed.
•       This source water condition map combines into one index the three
         disparate data sets as listed above.  All of the notes listed for the
         component data sets must be taken into account when using this map.


Plans to Improve this Data Layer
The partial characterization of source water condition in the Index of Watershed
Indicators Phase 1 will improve in future phases through four ongoing actions in the
drinking water program:
a) States are required, under the amendments of the Source Water Assessment
Provisions of the 1996 Safe Drinking Water Act (SDWA) Amendments, to complete
assessments by 1998 for all public water systems;
b) EPA will work with the States to access more complete source water information;
c) EPA will develop  a more robust ground water data layer in future phases of the Index
of Watershed Indicators through collaboration with  States, other Federal agencies, and
drinking water utility associations; and
d) EPA will incorporate in the Safe Drinking Water Information System (SDWTS) more
complete geographic references to public water system intakes and wellheads, including
latitude/longitude coordinates.

For More Information Contact:
Database Owner:
U.S. Environmental Protection Agency
Individual Contact
Carl Reeverts; 202 260-7273; E-mail: Reeverts.Carl@epamail.epa.gov
Data Source:
This map is a composite of three maps shown in the Supplemental Maps section.
Sources of data in these maps are:
Map 3a;  State FY 1994 305(b) assessments,
Map 3b;  SDWTS Violations and Treatment Data,
Map3c;  STORET data .
                                                                                                                                                           Page 13

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                                              4.  Contaminated Sediments
                                                         1980 -1993
 Analysis of Alaska and
 Hawaii reserved for Phase 2.
Watershed Classification
L ~1 Inconclusive Data
I    I Mxterate Degree of Concern
I    I High Degree of Concern
BB No Data for Assessment
  Index of Watershed
        Indicators
Sources: U.S. Environrrental Protection Agency
      National Sediment Inventory

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Map 4
Importance of Contaminated Sediments

Certain chemicals in water tend to bind to particles and collect in bottom
sediments.  When present at elevated levels in sediments, chemicals can kill or
harm bottom dwelling organisms. Pollutants in sediments can also accumulate
in aquatic organisms and move up the food chain to fish, shellfish and
eventually humans. Because of these effects, the presence of contaminated
sediment in a watershed is a good indicator of current aquatic condition,

U.S. EPA has recently completed a national assessment of sediment
contamination in waters throughout the United States.  As part of this
assessment, U.S. EPA compiled existing sediment chemistry, sediment
toxicity, and fish tissue residue data  from individual monitoring stations
throughout the nation. U.S. EPA applied a peer-reviewed weight-of-evidence
evaluation to determine the probability of association with adverse effects to
human health or aquatic life indicated by the data at each monitoring station.
Tier  1 monitoring stations indicate a higher probability of association with
adverse effects, and Tier 2 stations indicate lower to intermediate probability
of adverse  effects. Other monitoring stations do not indicate probability of
association with adverse effects.

Access to Detailed Data
Access to detailed data for each data  layer is available through "Surf Your
Watershed" at:   Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol)  addresses.

Data Sufficiency  Thresholds
All data U.S. EPA has collected for the National Sediment Inventory (NSI) from
States and other sources, such as Federal agencies, is used. The  IWI
distinguishes between watersheds which have no data and those  that have too
little data to draw conclusions from.

Notes on Interpreting this Information
•       Data Somewhat Consistent/Additional Data Needed
        See "Plans to Improve this Data Layer  for details.
•       Currently the NSI represents over 20,000 sites but covers only 11% of
        the Nation 's  river, lake and coastline sediments. Additional data needs
        to be collected assessing sediment conditions at more locations.
•       Watersheds with 20 or more Tier 1 stations and greater than 75% of all
        stations classified as either Tier 1 or Tier 2 have a high degree of
        concern; those with 10 or more Tier 1 stations and greater than 75% of
        all stations classified as Tier 1 or Tier 2 have a moderate degree of
        concern.

Plans to Improve this  Data Layer
To improve the data quality of this data layer, U.S. EPA will continue to
coordinate with U.S. EPA regional offices, States, Tribes, and others to compile
and identify additional data.  In addition, U.S. EPA is committed to promoting
state-of-the-art assessment methods to determine whether sediment at a site
poses a risk to human or ecological health.

For More Information Contact:
Database Owner
U.S. EPA Office of Science and Technology
Standards and Applied Science Division

Individual Contact
Jim Keating
E-mail:  keating.jim@epamail.epa.gov
Phone: (202) 260-3845

Data Source:
National Sediment Inventory (NSI), 1980-1993
        U.S. Environmental Protection Agency, Office of Science and
        Technology

U.S. EPA was specifically mandated by the Water Resources Development
Act to compile all existing information  on the quantity, chemical and physical
composition, and geographic location of pollutants in aquatic sediment,
including identification of those sediments which are contaminated.  As part of
this effort, U.S. EPA collects and evaluates sediment and fish tissue data from
State, U.S. EPA regional, and other monitoring programs.  The data are stored
in the National Sediment Inventory
                                                                                                                                                Page 15

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                         5.  Ambient Water Quality Data - Four Toxic Pollutants
                            Copper, Chromium (Hexavalent), Nickel and Zinc
                                                  1990-1995
Analysis ill Alaska and
liauaii reserved lor Phase 2
Watershed Classification
|    | 0 - 10° o Observations in Exceedence of National Criteria
Q   | 11 - 50% Observations in Exceedence of National Criteria
|    | >50% Observations in Exceedence of National Criteria
[^H Data Sufficiency Threshold Not Met
  Index of Watershed
        Indicators
Sources: U.S. Emironmental Protection Agency:
     Storage aid Retrieval (STORE!") System
1W7

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Map 5
Importance of Ambient Water Quality Data - Four Toxic
Pollutants

This data layer describes the degree to which monitoring of ambient
concentrations of selected toxic pollutants (copper, nickel, zinc and chromium
(hexavalent)) indicate an exceedance of the national chronic level criteria
developed by U.S. EPA for the pollutant.  (Note that State water quality
standards may differ from these numbers.)

Access to Detailed  Data
Access to detailed data for each data layer is available through "Surf Your
Watershed" at: . Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses.

Data Sufficiency Thresholds
Each watershed must contain at least 20 observations representing a minimum
of five sites over the six year period, 1990-1995.

Notes on Interpreting this Information
•   Data Somewhat Consistent/Additional Data Needed
     See "Plans to Improve this Data Layer" for details.
•   Ambient water quality data from STORET showing percent exceedences
     over a six year period (J 990-1995) are used The criteria used to
     calculate exceedences reflect whether fresh or marine waters were being
     sampled Marine waters were considered to be  those with hardness >
     1000 mg/l  Freshwater criteria for copper,  nickel and zinc were adjusted
    for hardness levels at each monitoring site.
•   The current STORET system contains limited information regarding data
    quality, and users do not always use identical methods or criteria to assess
    their waters. Also, much metals data in STORET was collected without the
    use of ultra clean monitoring methods recommended by the USGS
•  Most monitoring undertaken by States and Tribes is focused on rivers,
    lakes and estuaries with suspected or identified pollution problems.
    Assessments based on this type of monitoring may not be
    representative of the whole watershed and may overestimate the
    degree of concern.
•   National criteria are used because they can be applied across all
    watersheds universallv,  but they are  not necessarily the levels in State
    water quality standards

Plans to Improve this Data Layer
•   U.S. EPA will explore the use of a translation formula to convert total
    metals data to the dissolved form.
•   U.S. EPA is modernizing the STORET system to make it easier to access
    data, store information about data quality and equipment used to acquire
    the data, and expand the fields to store biological and habitat data.
•   The U.S. Geological Survey is addressing the issue of metals monitoring
    by developing ultra  clean trace metals monitoring methods. The USGS
    offers classes teaching these new methods to water  quality monitoring
    professionals.

For More Information Contact:
Database Owner:
U.S. Environmental Protection Agency, Office of Water

Individual Contact:
Louis Hoelman
E-mail: Hoelman.Louie@epamail.epa.gov
Phone: 202 260-7050

Data Source:
STOrage and RETrieval  System (STORET), 1990-1995
    U.S. Environmental Protection Agency, Office of Water.

U.S. EPA maintains a national database, the STOrage and RETrieval
(STORET) system, containing over 250 million observations of water quality
monitoring data from multiple sources both public and private. Most recently,
the U.S. Geological Survey's National Water Quality Assessment (NAWQA)
data has been added to the STORET system.

STORET is designed to store and disseminate basic information on chemical,
physical and biological quality of the nation's waterways within and contiguous
to the United States.

Additional Information
For additional information on STORET or data in STORET, call the
STORET hotline at 1-800-424-9067
                                                                                                                                             Page 17

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                     6.  Ambient Water Quality Data - Four Conventional Pollutants
                             Ammonia, Dissolved Oxygen, Phosphorus and pH
                                                   1990 -1995
Analysis at" Alaska and
Hauaii reserved for Phase 2
 Watershed Classification
 I    | 0 -1 OP/o Observations in Exceedence of Selected Reference Level
 L   I 11 - 25% Observations in Exceedence of Selected Reference Level
 |_   | >25% Observations in Exceedence of Selected Reference Level
   §| Data Sufficiency Threshold Not Met
  Index of Watershed
        Indicators
Sources: U.S. EmironriKiital Protection Agency:
     Storage aid Retrieval (STORE!) System

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Map 6
Importance of Ambient Water Quality Data - Four
Conventional Pollutants

This data layer describes the degree to which monitoring of ambient
concentrations of selected conventional pollutants (ammonia, phosphorus, pH,
and dissolved oxygen) indicate an exceedance of a national reference level
developed by U.S. EPA for the pollutant.  For this data layer, ambient water
quality data from STORET showing percent exceedences over a six year period
(1990-1995) are used. The reference levels for each conventional pollutant are:
ammonia (recommended chronic levels for ammonia were taken from Ambient
Water Quality Criteria for Ammonia, EPA 440/5-85-001, p. 97 and reflect
temperature and pH adjustments), phosphorous (0.1 mg/1), and pH (6.0 to 9.0 ).
Dissolved oxygen is not a pollutant, but is a measure of oxygen demanding
wastes.  The reference for dissolved oxygen levels is 5 mg/1  Note that State
water quality standards may differ from these concentrations .

Access to Detailed Data

Access to detailed data for each data layer is available through "Surf Your
Watershed" at:   Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses.

Data Sufficiency Thresholds

Each watershed must contain at least 20 observations representing a minimum of
five sites over the six year period, 1990-1995.

Notes on Interpreting this Information

»       Data Somewhat Consistent/Additional Data Needed
        See "Plans to Improve this Data Layer" for details.
•       The current STORET system contains limited information regarding
        data quality and STORET users do not necessarily use identical
        methods or criteria to assess their waters.
»       Most monitoring undertaken by States and Tribes is focused on rivers,
        lakes and estuaries with suspected or identified pollution problems.
        Assessments based on this type of monitoring may not be representative
        of the whole watershed and may overestimate the degree of concern.
•      National reference levels are used because they can be applied across
        all watersheds universally, but they are not necessarily of concern to
        individual States.

Plans to Improve this Data Layer

•      U.S. EPA is modernizing the STORET system to make it easier to
        access data; store information about data quality and equipment used to
        acquire the data; and expand the fields to store biological and habitat
        data.

For More Information Contact:

Database Owner:
U.S. Environmental Protection Agency, Office of Water

Individual Contact:
Louis Hoelman
E-mail: Hoerman.Louie@epamail.epa.gov
Phone: 202 260-7050

Data Source:
STOrage and RETrieval System (STORET), 1990-1995
U.S. Environmental Protection Agency, Office of Water.

U.S. EPA maintains a national database, the STOrage  and RETrieval (STORET)
system, containing over 250 million observations of water quality monitoring
data from multiple sources both public and private.  Most recently, the U.S.
Geological Survey's National Water Quality Assessment (NAWQA) data has
been added to the STORET system.

STORET is designed to store and disseminate basic information on chemical,
physical and biological quality of the  nation's waterways within and contiguous
to the United States.

Additional Information

For additional information on STORET or data in STORET, call the STORET
hotline at 1-800-424-9067.
                                                                                                                                            Page 19

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                                            7. Wetland Loss Index
                                     Combines  Both Recent (1982 -1992)
                                  and Historic (1780s - 1980s) Wetland Loss
AnaK sis ot Alaska and
1 lauai i iv-sen ed for Phase 2
Watershed Classification
I    | Low Level of Wetland Loss
I    | Moderate Level of Wetland Loss
|    | High Level of Wetland Loss
  Index of Watershed
        Indicators
Sources: Natural Resources Conservation Service
     U.S. Fish and Wildlife Sen ice
                                                                                                       June 23, 1SW

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Map?
Importance of Wetland Loss Index
Wetlands make important contributions to the health of aquatic systems on a watershed
basis by purifying water, filtering runoff, abating floods, and decreasing erosion.  In
addition, wetlands provide habitat for countless numbers of plants and animals including
over 40% of all federally listed threatened or endangered species. Many wetland plants
and animals support recreation and commercial industries. For example, wetlands act as
nurseries for over 80% of coastal fisheries. In addition, millions of Americans are
annually drawn to wetlands for bird watching, hunting, fishing, and enjoying the natural
beauty of wetland ecosystems. Although wetland loss rates are slowing, the United
States continues to lose approximately 70,000 to 90,000 acres of wetlands on non-
federal, rural lands each year.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed"
at:   Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.


Description of the Data Layer
Recent wetlands loss rates (Map 7 a, Natural Resources Inventory (NRI), 1982-1992)
were combined with historic loss rates (Map 7b, National Wetlands Inventory (NWI),
1780s-1980s) to form an index. The combined index is a more robust indicator of
watershed condition than either loss rate used independently.
•  Natural Resources Inventory. Natural Resources Conservation Service (NRCS)
   reports on wetland acreage on rural, non-federal lands that constitute about 75% of
   the Nation's land base.  (Reported at 6-digit accounting unit)
•  National Wetlands Inventory. The U.S. Fish and Wildlife Service maintains wetlands
   acreage data on federal and non-federal lands. (State level)
To create the Wetlands Loss Index, The IWI assigned the appropriate NWI State data to
Accounting Units and combined it with NRI data. The following chart was used to
assign scores (0 = low level of wetland loss, 1 = moderate level of wetland loss, and 2 =
high level of wetland loss)
                                              NRI: % loss between 1982 and 1992
                                                 (by 6 digit accounting unit)
       NWI  Historic % loss from

           1780s to 1980s

             (by State)
Data Sufficiency Threshold
All available data were used
<30%
30-70%
>70%
0
1
2
1
1
}
2
2
2
Notes on Interpreting this Information
•  Data Need to be Much More Consistent/Much Additional Data Needed
   See "Plans to Improve this Data Layer" for details.
•  Existing inventories of acreage change are national in scope and designed to provide
   information on national -wetlands losses and gains by wetland type  They were not
   designed to track wetland change on a -watershed basis and, in most cases, do not
   provide robust State or -watershed information
•  NWI and NRI were designed to answer different questions and have different
   sampling procedures.  NRI data used in this analysis were adjusted to reflect
   differences and to account for some changes in NRCS's data collection methods.
   Unlike the other 14 IWI data layers, this data is reported at the 6 digit accounting
   unit scale (each 6 digit unit contains several 8 digit units), which IWI interpolated to
   the 8 digit area


Plans to Improve this Data Layer
1 U.S. EPA is working towards reporting on both the quantity and quality of wetlands.
However, wetland biological monitoring programs are still in their infancy.  As States
establish wetland monitoring programs and include this information in their 305(b)
reports, better data will be available for this data layer
2. U.S EPA is continuing to work with the USFWS and NRCS to monitor wetland loss
and report improvements  in wetland acreage.  The Federal Geographic Data Committee
Wetlands Subcommittee is exploring new approaches of tracking wetland acreage,
reporting more frequently, and reporting at the 8-digit watershed level

For More  Information  Contact:
Database Owners:
1.  NRI: USDA National  Resources Conservation Service (NRCS)
2.  NWI: U.S. Fish and Wildlife Service (USFWS)
Individual Contacts:
NRI:    Bob Kellogg                        NWI:
E-mail:  rkellogg@nhq.nrcs.usda.gov          E-mail
Phone:  (202)690-0341                      Phone
Data Source:
1.  Natural Resources Inventory (NRI), 1982  and 1992
2.  National Wetlands Inventory (NWI),  1780s-1980s


Additional Information
For information about wetlands, contact:
EPA Wetlands Information Hotline (contractor operated)
1-800-832-7828  ot   http://www.epa.gov/OWOW/wetlands/\\etlme html
For additional information about the wetlands data layer, contact:
Tom Danielson, U.S Environmental Protection Agency  Wetlands Division
E-mail: Danielson Tomfojepamail.epa.gov  Phone (202)260-5299
                                                                      Page 2!
Tom Dahl
rom_Dahlfa!mail fws.gov
(813)570-5429

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                                      8. AquaticAVetland Species at Risk
                                                        19%
            VVJ
Aiiahsis d' .Alaska and
Hawaii resened for Phase 2
Watershed Record
|    |  1 Species Kno\\n to be at Risk
j    j  2 - 5 Species Knossn to be at Risk
|~  !  >5 Species Kno\\n to be at Risk
      No Recorded Data
 Index of Watershed
       Indicators
Sources: State Natural Hnitage Dbta Center
      Tit Nature Consiavancy

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Map 8
Importance of Aquatic/Wetland Species at Risk
This data layer provides information about the presence of species at risk in a given
watershed. The State agency-based Natural Heritage Network and The Nature
Conservancy (TNC) assess the conservation status of plants and animals, and map
out the population occurrences of those species at greatest risk of extinction. This
indicator represents the number of aquatic or wetland-dependent species documented
in a watershed that are classified by the Heritage Network as critically imperiled
(identified by TNC as Gl), imperiled (G2), or vulnerable (G3), or that are listed
under the  federal Endangered Species Act (ESA) as threatened or endangered.

The presence of rare or endangered species in a watershed is not necessarily an
indication of poor watershed conditions. Indeed, it more likely indicates the
opposite: in  many instances these species persist only in areas of exceptionally high
quality habilal. The presence of  species at risk in a watershed indicates, however,
that these  watersheds are especially vulnerable to future water quality or habitat
degradation, which could jeopardize the maintenance or recovery of these organisms.
Watersheds considered vulnerable because of the presence of species at risk may
require special attention to protect or restore water quality in order to maintain these
biological values.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your
Watershed" at:    Click on the data layer of
interest lo find documentation and FTP (File Transfer Protocol) addresses.

Access to detailed data on the species at risk documented within a given watershed
should be  requested through the relevant State Natural Heritage Data Center. Contact
information for the  48  State programs that provided data to the Index of Watershed
Indicators can be accessed at http://www.heritage.tnc.org/nhp/directory/dirlist.html.

Data Sufficiency  Thresholds

1 he presence ol an  individual species in a watershed is based on the existence in the
heritage databases ol at least one documented occurrence in that watershed since
l')7()  Furtheimore, occurrences must be gco-refercnccd at a precision-level of at
least onc-mmule latitude/longitude. This map includes only species  thai meet the
lullowmg two criteria for status and habitat use: 1) Heritage/Conservancy
conservation status of critically  imperiled to vulnerable (G1-G3), or federal  ESA
status ol threatened or endangered; and 2) dependent on aquatic or wetland habitats
based on selection criteria developed as part of the U.S. EPA Environmental
liulicntiii-s <>/ tt'tifcr (Jutililv in the United,SVd/i'.v report.
Notes on Interpreting this Information
•      Data Need to be Much More Consistent/Much Additional Data Needed
        See  "Plans to Improve this Data Layer "for details.
»      State Natural Heritage Data Centers process data according to
        consistent inventory and data management standards, producing
        information that is comparable from State to State.
*      Aquatic inventory efforts and data processing backlogs, however, varv
        from State to State. Thus while available data is comparable, level of
        data completeness is inconsistent.
•      Heritage species occurrence data are not based on comprehensive
        inventories of each watershed and major inventory gaps remain,
        especially for aquatic species. For this reason, some watersheds may
        acluallv have more species at risk than indicated.
•      Similarly, lack of data for a watershed cannot be construed to mean
        that no species at risk are present. It is not currently possible using this
        data set to distinguish  between luck of inventory data for a watershed
        and the absence of species at risk in that watershed.

Plans to Improve this Data Layer
Working with U.S. EPA's Office  of Information Resources  Management, plans
are being developed that could improve heritage data consistency among States,
reduce data processing backlogs, and create a more readily accessible national
element occurrence data set. In the short-term, information could be compiled
and mapped for specific groups of organisms (e.g., fish and  mussels) to
complement the occurrence information available and reduce watershed data
gaps on the map.

For More  Information Contact:
Database Owners:
State Natural  Heritage Data Centers
http://www.heritage.tnc.org/nhp/dircclory/dirlist.html
Data compiled and analyzed  by The Nature Conservancy
Individual Contact:
Bruce Stein
E-mail: bstein(<(Hnc.org
Phone: 703-841-2711

The basic locational data underlying this map are developed and stored by the State
agency-based Natural Heritage Data Centers. These State data centers document the
location of rare and endangered species for  use in environmental planning and
conservation efforts. Eoeational data from 48 States were aggregated and combined
with conservation status and habitat use information maintained by TNC' to develop
this map.
                                                                    I'agc 23

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                9.  Pollutant Loads Discharged Above Permitted Limits - Toxic Pollutants
                                                         1995
            v\J
Anah sis of Alaska and
I la\\aji reserved for Pliase 2
Watershed Record
I    I No DMR Data Entry Requirements for all Dischargers,
    or No NPDES Dischargers
,	, No Aggregate Loads in Excess of Total Penrrit Limits
    or No Pennitted Dischargers
I    I Up to 20% Average Load Over Pennitted Limits
  Z] IVtore Than 20% Average Load Over Pennitted Limits
    Insufficient Data for >10%of Major Dischargers or for >50%
    of Minor Dischargers when No Major Dischargers Present
                                                              Index of Watershed

                                                                    Indicators
                                                            Sources: U.S. Environmental Protection Agency
                                                                  Permit Compliance System
                                                                                                                    Ti.t93.7rl2

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Map 9
Importance of Pollutant Loads Discharged Above Permitted
Limits - Toxic Pollutants

As one of the activities to maintain water quality in the US, the Clean Water Act requires
that U.S. EPA or States set limits through permits under the National Pollutant Discharge
Elimination System (NPDES) on the amount of pollutants that facilities such as sewage
treatment or industrial plants may discharge into a waterbody.  Limits for these
discharges are set according to national technology-based standards and the conditions of
the waters that receive the discharge based  on State water quality standards. This data
layer adds up the total amount of pollutants allowed to be discharged through NPDES
permits into each watershed, and compares this total amount to the total amount of
pollutants actually discharged to determine the amount in excess of the allowable
discharge.

Watersheds with pollutant loads greater than the total permit limits of all facilities are
considered vulnerable to future declines in  aquatic health. This data layer provides
insight into whether the total of all discharges exceeds the total of all permitted limits for
all toxic pollutants named in the permits. Such toxic pollutants include cadmium,
copper, lead, mercury, and others. Watersheds with the highest scores have greater
potential for possible future environmental  decline due to toxic pollutant exceedences.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed" at:
.  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Data Sufficiency Thresholds
A watershed was considered to have insufficient data if more than 10% of the major
facilities in the watershed did not have Discharge Monitoring Form (DMR) data  in the
Permit Compliance System (PCS), or,  if there were no major facilities, more than 50% of
the minor facilities in the watershed did not have DMR data in PCS.

Notes on Interpreting this Information
*       Data Consistent/Sufficient Data Collected (permittees must follow NPDES
         requirements in reporting data)
         See "Plans to Improve this Data  Layer for details.
*       The discharge data from  "Minor" facilities (municipal facilities with flow less
         than 1 million gallons a dav, or non-municipal facilities with a major rating
         code (a code assigned based on such factors as type of waste, toxicity, flow,
         and distance from a drinking water source) below the minimum requirement
         to be classified "Major") are not required to be entered into PCS.  Therefore,
         this data laver mav not represent all permitted dischargers in a watershed.
•        Due to inconsistent reporting of monitoring data below the method detection
         limit across the country, DMR data below detection were not used in this
         analysis.  Facilities that had a mixture of data above and below the detection
         limit were included in the analysis but only data above detection were used to
         calculate loadings.
 *       Violations ofdailv maximums, where there are no monthly average limits, were
         evaluated as 30 days of violation except chlorine,  which was calculated as only
         a one-day violation.  This minimizes the impact of chlorine while maximizing
         the impact of the other toxic pollutants.  Due to the frequency at which
         chlorine is monitored and the probability of a short duration violation,
         chlorine violations, if treated as 30 days of violation, would significantly mask
         other toxic pollutant violations which may have more impact on the receiving
         waterbodv (chlorine dissipates quickly while these other toxic pollutants do
         not).


Plans to Improve this Data Layer
The data contained in  PCS are of high quality, but the Office of Water  and the Office of
Enforcement and Compliance Assurance are still taking actions to improve the data in
order to address:  (1) changes in permitting requirements from  year to year; (2)
inconsistent reporting from facilities required to submit discharge data; (3) facilities not
required to report discharge data but still responsible for releasing contaminants to
receiving waters; and  (4) different PCS parameter codes for the same pollutant,  hi
addition, the U.S. EPA plans to provide guidance to regional and State permit writers on
how to enter data more accurately and consistently into PCS.

For More Information Contact:
Database Owner: U.S. EPA, Office of Enforcement and Compliance Assurance
Individual Contact: Steve Rubin E-mail: Rubin.Steven@epamail.epa.gov Phone: (202)
564-7052
Data Source:  Permit Compliance System (PCS), U.S. EPA From the 1995  self-
monitoring measurement data reported on the NPDES DMR form
Additional Information
  US EPA Regional Contacts
  1 - Robin Neas                               2 - Roger K Vann
  E-mail. Neas Robin@epamail epa gov             E-mail  Vann Roger@epamail epa gov
  Phone: 617/565-4869                          Phone  212/637-3321
  3 - Edna Jones                               4 - Mike Donehoo
  E-mail' Jones.Edna@epamail.epa.gov              E-mail. Donehoo.Mike@epamail epa gov
  Phone: 215/566-5795                          Phone  404/562-9745
  5 - Arnie Leder                               6 - Cathy Bius
  E-mail. Leder.Amold@epamailepa.gov            E-mail  Bius.Cathenne@epamail epa gov
  Phone  312/886-0133                          Phone  214/665-6456
  7 - Michael Rosenbaum                        8 - Josie Hernandez
  E-mail' Rosenbaum Mike@epamail.epa gov        E-mail' Hernandez Josie@epamail epa.gov
  Phone: 913/551-7450                          Phone. 303/312-7079
  9-CareyHouk                               10  - Jeannine  (JJ) Brown
  E-mail Houk Carey@epamail epa gov             E-mail:  BrownJeannine@epamail epa gov
  Phone: 415/744-1886                          Phone. 206/553-1058
                                                                                                                                                               Page 25

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            10. Pollutant Loads Discharged Above Permitted Limits - Conventional Pollutants
                                                        1995
            \4J
Analysis of Alaska and
tfcmaii reserved for Phase 2
Watershed Record
I  '..  1 No DMR Data Entry Requirements for all Dischargers.
	or No NPDES Dischargers
~ZH No Aggregate Loads in Excess of Total Peirrrit Limits
    or No Pennitted Dischargers
I    I Up to 40% Average Load Over Pennitted Limits
  H More Than 40% Average Load Over Pennitted Limits
Hi! Insufficient Data for >10%of Major Dischargers or for >50%
    of Minor Dischargers when No Major Dischargers Present
  Index of Watershed

        Indicators
.Sources: U.S. Emironmental Rxiteetion Agency
     Permit Compliance System
June 25. i

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Map 10
Importance of Pollutant Loads Discharged Above Permitted
Limits - Conventional Pollutants

As one of the activities to maintain water quality in the U.S., the Clean Water Act
requires that U.S. EPA or States set limits through permits under the National Pollutant
Discharge Elimination System (NPDES) on the amount of pollutants that facilities such
as sewage treatment or industrial plants may discharge into a waterbody. Limits for these
discharges are set according to national technology-based standards and the conditions of
the waters that receive the discharge based on State water quality standards. This data
layer adds up the total amount of pollutants allowed to be discharged through NPDES
permits into each watershed, and compares this total amount to the total amount of
pollutants actually discharged to determine the amount in excess of the allowable
discharge.

Watersheds with pollutant loads greater than the total permit limits of all facilities are
considered vulnerable to future declines in aquatic health. This watershed vulnerability
data layer provides insight into whether the total of all discharges by facilities exceeds the
total of all permitted limits for all conventional pollutants named in the permits.  Such
conventional pollutants include biochemical oxygen demand, total  suspended solids,
nutrients, and others. Watersheds with the highest scores have greater potential for
possible future environmental decline due to conventional pollutant exceedences.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed" at:
.  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.


Data Sufficiency Thresholds
A watershed was considered to have insufficient data for this analysis if greater than 10%
of the major facilities in mat watershed did not have Discharge Monitoring Report
(DMR) data in the Permit Compliance System (PCS), or, if there were no major facilities,
more than 50% of the minor facilities in that watershed did not have DMR data in PCS.


Notes on Interpreting this Information
*       Data Consistent,'Sufficient Data Collected (permittees must follow NPDES
         requirements in reporting data)
         See  "Plans to Improve this Data Layer "for details.
*        The discharge data from "Minor' facilities (municipal facilities with flow less
         than 1 million gallons a day, or non-municipal facilities with a major rating
         code (a code assigned based on such factors as type of waste, toxicity,flow,
         and distance from a drinking water source) below the minimum requirement to
        be classified "Major") are not required to be entered into PCS Therefore,
        this data layer may not represent all permitted dischargers in a watershed.
 *       Due to inconsistent reporting of monitoring data below the method detection
         limit across the country, DMR data below detection were not used in this
         analysis.  Facilities that had a mixture of data above and below the detection
         limit were included in the analysis but only data above detection were used to
         calculate loadings.
 •       Violations of daily maximums, where there are no monthly average limits, were
         evaluated as 30 days of violation.


Plans to Improve this Data Layer
The data contained in PCS are of high quality, but the Office of Water and the Office of
Enforcement and Compliance Assurance are still taking actions to improve the data in
order to address: (1) changes in permitting requirements from year to year; (2)
inconsistent reporting from facilities required to submit discharge data; (3) facilities not
required to report discharge data but still responsible for releasing contaminants to
receiving waters; and (4) different PCS parameter codes for the same pollutant,  hi
addition, the U.S. EPA plans to provide guidance to regional and State permit writers on
how to enter data more accurately and consistently into PCS.


For More Information Contact:
Database Owner:  U.S. EPA, Office of Enforcement and Compliance Assurance

Individual Contact: Steve Rubin, E-mail: Rubin.Steven@epamail.epa.gov  Phone:  (202)
564-7052

Data Source
Permit Compliance System, U.S. Environmental Protection Agency
From the 1995 self-monitoring measurement data reported by NPDES Discharge
Monitoring Report (DMR) form.
Additional Information
 U.S. EPA Regional Contacts-
 1 - Robin Neas
 E-mail: Neas.Robm@epamail.epa.gov
 Phone:  617/565-4869
 3 - Edna Jones
 E-mail: Jones.Edna@epamail epa.gov
 Phone.  215/566-5795
 5 - Arrue Leder
 E-mail  Leder Arnold@epamail.epa.gov
 Phone:  312/886-0133
 7 - Michael Rosenbaum
 E-mail: Rosenbaum.Mike@epamail.epa gov
 Phone:  913/551-7450
 9 - Carey Houk
 E-mail  Houk.Carey@epamail.epa gov
 Phone: 415/744-1886
2 - Roger K. Vann
E-mail: Vann.Roger@epamail epa.gov
Phone: 212/637-3321
4 - Mike Donehoo
E-rnaif Donehoo.Mike@epamail epa.gov
Phone' 404/562-9745
6 - Cathy Bius
E-mail: Bius.Catherine@epamail epa.gov
Phone. 214/665-6456
8 - Josie Hernandez
E-mail: Hernandez.Josie@epamail.epa.gov
Phone: 303/312-7079
10 - Jeannine (JJ) Brown
E-mail  Brown.Jeanmne@epamail.epa.gov
Phone. 206/553-1058
                                                                                                                                                               Page 27

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                                             11. Urban Runoff Potential
                                                           1990
Analysis of Alaska and
Ha\\ai i reserved for Phase 2
Watershed Estimates
   ^] < 1% Land Area Above 25% Imperviousness
       - 4% Land Area Above 25% Imperviousness
    I >4% Land Area Above 25% Imperviousness
     Insufficient Data to Make Estimates
Index of Watershed
      Indicators
   Sources: U.S. Census Bureau
         U.S. Geological Survey
                                                                                                               June ?Q 1997

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Map 11

Importance of Urban Runoff Potential

Imperviousness is a useful indicator to predict impacts of land development
on aquatic ecosystems. Studies have linked the amount of imperviousness to
changes in the hydrology, habitat structure, water quality and biodiversity
of aquatic ecosystems (Watershed Protection Techniques, Vol. 1, No. 3, Fall
1994). Increased imperviousness can change the hydrology of a receiving
stream, increasing runoff volume and rate and decreasing the receiving
streams capacity to handle floods.

Access to Detailed Data

Access to detailed data for each data layer is available through "Surf Your
Watershed" at: . Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses.

Description of the Data Layer

This indicator was developed based on the block group, a geographic area
defined by the U.S. Census Bureau for purposes of reporting demographic
data. A database of urban area was developed based on the 1978 U.S.
Geological Survey (USGS) land use data and estimated population growth
from 1978 to 1990. A relationship between population growth and
expansion of urban area was established for each block group to estimate the
1990 urban area and imperviousness area for each block group. An urban
runoff potential was then calculated for each block group using a simple
runoff estimation method based on regional rainfall characteristics and the
amount of urban and imperviousness area.  This urban runoff potential was
then aggregated at the 8-digit watershed level to determine an urban runoff
potential indicator for the Index of Watershed Indicators.
Data Sufficiency Thresholds

All block group data were used.

Notes on Interpreting this Information

•      Data Somewhat Consistent/Additional Data Needed
        See "Plans to Improve this Data Layer "for details.
•      Indicator represents 1990 urban conditions.  Changes since 1990
        are not reflected.
•      The relationship developed to estimate 1990 urban area and
        imperviousness area may not accurately reflect current conditions.
•      Stormwater management practices are not included in the
        determination of the indicator.  These practices, if properly
        designed and maintained, can mitigate impacts caused by
        imperviousness.

Plans to Improve this Data Layer

Plans to be determined.

For More Information Contact:
Database Owner:
U.S. Environmental Protection Agency, Office of Water

Individual Contact:
John Kosco
E-mail: Kosco.John@epamail.epa.gov
Phone: 202 260-6385

Data Source:
U.S. Census Bureau - 1990 population and housing, 1980 population
U.S. Geological Survey - GIRAS Land Use, 1978
                                                                                                                                      Page 29

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                                 12. Index of Agricultural Runoff Potential
                              (Based Upon Nitrogen, Sediment and Pesticide)
                                                  1990 -1995
AnaKsis at' Alaska and
Hawaii reserved for Phase 2
Watershed Classification
|    | Low Level of Potential Impact
|    | Moderate Level of Potential Impact
|    | High Level of Potential Impact
BHii Insufficient IWI Data
  Index of Watershed
       Indicators
Source: Natural Resources Conservation Service

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Map 12
Importance of Index of Agricultural Runoff Potential

A composite index was constructed to show which watersheds had the
greatest potential for possible water quality problems from combinations of
pesticides, nitrogen, and sediment. Watersheds with the highest composite
score have a greater risk of water quality impairment from agricultural
sources than watersheds with low scores.  Watersheds could be ranked high
because of a very high ranking of a single component, or moderately high
rankings from two or more components.

Access to Detailed Data

Access to detailed data for each data layer is available through "Surf Your
Watershed" at:  Click on the data
layer of interest to find documentation and FTP (File Transfer Protocol)
addresses.

Description of the Data Layer

The composite indicator was constructed by ranking watersheds for each of
the three components -- potential pesticide runoff, potential nitrogen runoff,
and potential in-stream sediment loads — and then summing the rankings
for each watershed. This procedure weighted each of the three components
equally.  Individual maps for the three components are shown in
'''Supplemental Maps" following

Data Sufficiency Thresholds

No data sufficiency threshold was applied.
Notes on Interpreting this Information

•       Data Consistent/Sufficient Data Collected
        See "Plans to Improve this Data Layer"for details,
•       The composite indicator primarily represents sources of pollutants
       from cropland. It does not include any components for rangeland,
        pastureland, or privately managed forest land.
•       This composite map combines three disparate agricultural
        vulnerability indicators - pesticide runoff, nitrogen runoff, and in-
        stream sediment loads. See the individual data layer maps in
        "Supplemental Maps "for additional information and caveats for
        each of these component indicators.

Plans to Improve this Data Layer

Efforts will  be made to  include additional vulnerability components for
rangeland, pastureland, and forest land.

For More Information Contact:

Database Owner

U.S. Department of Agriculture, NRCS

Individual Contact
Robert Kellogg, NRCS/USDA
E-mail: robert.kellogg@usda.gov
Phone:(202)690-0341

Data Source:
National Resources Inventory
        U.S. Department of Agriculture, Natural Resources Conservation
        Service
                                                                                                                                    Page 31

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                                           13. Population Change
                                                 1980-1990
Aiiah sis of Alaska and
Hawaii reserved for Phase 2
Watershed Census
     Declined or No Change
     10 - 7% Increase
     | >7% Increase
      Insufficient IWI Data
Index of Watershed
     Indicators
   Source: U.S. Census Bureau
                                                                                                  JunelZ 1597

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Map 13
Importance of Population Change

The growth of human populations can result in increased pollution of our
waters as land cover and land uses change. These changes include
construction impacts,  increased impervious surfaces, loss of wetlands, and
increased sewage flows. Population often increases in areas with growing
sources of employment, also bringing industrial and commercial impacts as
well.  This data layer identifies changes in population in watersheds based
on the U.S. Census Bureau data. It assigns scores based on whether the
population has remained stable or decreased, increased from 0 to 7%, or
increased more than 7%.

Access to Detailed Data

Access to detailed data for each data layer is available through "Surf Your
Watershed" at: .  Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses

Data Sufficiency Thresholds

Watersheds with a density of less than 6.88 people per square mile were
placed in the category of "declined or no  significant change."  Density
values less than 6.88 represent the 5th quantile and are considered to be so
low as to have minimal impact on water quality. Population changes
between zero and 7 percent (but with densities greater than 6.88) were
placed in the second category, while population changes greater than seven
percent were placed in the third category.
Notes on Interpreting this Information

•       Data Consistent/Sufficient Data Collected
        See "Plans to Improve this Data Layer  'for details.
•       The calculation of population change was done at the 8-digit
        Cataloguing Unit level which could mask areas of change in
        watersheds that have block groups with increasing populations
        and block groups with decreasing populations

Plans to Improve this Data  Layer

Data will be revised after the next census.

For More Information Contact:

Database Owner
U.S. Census Bureau

Individual  Contact

TodDabolt,U.S. EPA
202 260-3697
E-mail: Dabolt.Thomas@epamail.epa.gov

Data Source:
U.S. Census Bureau, 1980-1990.
                                                                                                                                      Page 33

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                               14. Hydrologic Modification Caused by Dams
                                                  1995-1996
Analysis of Alaska and
1 Ia\\aii reserved for Phase 2
Watershed Classification
|    | Low Volumes of Impounded Water
|    | Moderate Volumes of Impounded Water
~   | High Volumes of Impounded Water
     No Recorded Dams
Index of Watershed
     Indicators
Source: U.S. Amn Corps of Puiginoers

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Map 14
Notes on Interpreting this Information
Importance of Hydrologic Modification Caused by Dams

The health of the aquatic system in a watershed can be compromised by
extensive impoundment or hydrologic modification of water resources.
This index shows the relative dam storage capacities in watersheds, which
provides a picture of the relative degree of modification of hydrologic
conditions in a watershed.  This data is used by Federal Emergency
Management Agency to assess overall safety hazards posed  by dams in the
United States.  The data can also be used to analyze needs and target
resources for navigation, flood control, water supply, hydroelectric power,
environmental restoration, wildlife protection, and recreational projects.

This database is an inventory of U.S. dams in excess of six feet in height
and a maximum water impounding capacity  of at least fifty acre feet; or
dams at least  twenty-five feet in height and a maximum water
impoundment capacity in excess of fifteen acre-feet.  It contains
information on 75,187 dams throughout the  U.S. and its territories.  The
U.S. Army Corps of Engineers updates the database with assistance from
the States and territories

Access  to Detailed Data

Access to detailed data for each data layer is available through "Surf Your
Watershed" at:   Click  on the data
layer of interest to find documentation and FTP (File Transfer Protocol)
addresses.

Data Sufficiency Thresholds

All data is used for this data layer except that on a river with multiple dams,
waters are not counted twice.
•       Data Somewhat Consistent/Additional Data Needed
        See "Plans to Improve this Data Layer" for details.
•       The database does not reflect actual stream channel modifications.
•       The database does not reflect the different uses of impounded
        "waters.

Plans to Improve this Data Layer

EPA intends to deal better with the impacts of small dams, dry dams, and
reservoirs. In addition, the Nature Conservancy is developing an Index of
Hydrologic Modification that in time may provide more predictions of
aquatic resource modification.

For More Information Contact:

Database Owner:
U.S. Army Corps of Engineers

Individual Contact:
Bob Bank
E-mail: Robert,Bank@inet.hq.usace.army.mil
Phone:(202)761-1660

Data Source:
National Inventory of Dams Database
        U.S. Army Corps of Engineers. 1995-199
                                                                                                                                      Page 35

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                               15.  Estuarine Pollution Susceptibility Index
           Based Upon Pollution Loads and Pollution Retention Characteristics of Estuaries
                                                1989-1991
Analysis at'Alaska and
Hawaii reserved for Phase 2
Coastal Watershed Classification
|    | Low Susceptibility
|    | Moderate Susceptibility
I    | High Susceptibility
     Index of Watershed
          Indicators
Source: National Oceanic and Atmospheric Administration
6ERA
  June 22,1997
                                                                                                         Tl -1-9?^ 3rt

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Map 15
The Importance of Estuarine Pollution Susceptibility Index

Coastal lands comprise approximately 11 percent of the area of the United States;
however, this area contains nearly 45 percent of the population.  Indications are that
coastal population growth will continue to increase. As these areas come under
increased stress, better information will be required in order to initiate effective
management strategies. The Estuarine Pollution Susceptibility Index provides a
tracking method for the susceptibility to pollution of coastal watersheds.
Susceptibility is defined as the relative vulnerability of an estuary to concentrations
of dissolved and particulate substances.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed" at:
.  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Description of the Data Layer
National Oceanic and Atmospheric Administration (NOAA) built the National Estuarine
Inventory (NEI) around a watershed-based spatial framework which defined and
characterized the nation's estuarine resource base in an effort to develop a national
estuarine assessment capability. The NEI framework  was included in a larger Coastal
Assessment Framework (CAF) which identifies all watersheds associated with the coast.
The CAF framework data includes a set of approximately 700 cataloging units which are
used with geographic information systems to conduct  a variety of spatial analyses.
NOAA then applied to these 700 cataloging units a Strategic Assessment for Near
Coastal Waters which quantifies susceptibility to pollution by the dissolved concentration
potential (DCP), the particle retention efficiency (PRE),  and by the estimated loadings
and predicted concentrations of nitrogen (N) and phosphorus (P).

The DCP characterizes the effect of dilution and flushing on a per-unit-load of a
dissolved and conservative pollutant to an estuary.  The parameter is based on the
fractional freshwater method for predicting the concentration of a pollutant. The DCP
used in conjunction with estimated nutrient loads provides a first order approximation of
nutrient conditions within an estuary.  The PRE is based upon an empirical relationship
between sediment trapping efficiency and a capacity to inflow ratio. The PRE assumes
that die relative  ability of an estuary to trap sediment correlates to its ability to retain any
associated toxic pollutant.

Currently, NOAA assessments exist for over 130 estuaries within the CAF. The date
for most assessments is 1990, however, the mid-Atlantic and south Atlantic were
updated in 1996.  To develop the Index of Watershed Indicators (IWI) data layer,
information from the CAFs was applied to the 150 U.S. Geological Survey (USGS)
cataloguing units of the coastal United States and appropriate scores were assigned.
Data Sufficiency Threshold
All NOAA assessments were used.

Notes on Interpreting this Information
*       Data Consistent/Sufficient Data Collected
         See  "Plans to Improve this Data Layer "for details.
*       There are some boundary discrepancies between a few USGS units used in
         the IWI assessment and the Coastal Assessment Framework.

Plans to Improve this Data  Layer
*       Replacing the 22.25 km oceanic boundary with a 12 nautical mile
         Territorial Sea and Contiguous Zone boundary;
»       Revising some of the boundaries that define the  CAF drainage areas to
         match the USGS Cataloging units;
*       Replacing international boundaries;
»       Adding Canadian drainage boundaries;
*       Correcting errors based upon user comments.

For More  Information Contact:

Database Owner
National Oceanic and Atmospheric Administration
Individual Contact:
NOAA: C. John Klein
E-mail: Iklein@seamail.nos.noaa.gov
Phone: 301-713-3000 ext.  160

Data Source:
U.S. EPA:  Greg Colianni
E-mail: Cohanni.Gregory@epamail.epa.gov
Phone: 202-260-4025
1.  Coastal Assessment Framework.  Digital boundary files. National Oceanic and
Atmospheric Administration (NOAA), 1990.
   National Coastal Pollution Discharge Inventory. NOAA/NOS.  Unpublished data.
   Strategic Assessment for Near Coastal Waters, NOAA.  (Separate Reports)
   A.  Susceptibility and Status of North Atlantic Estuaries to Nutrient Discharges.
   NOAA/U.S. Environmental Protection Agency (U.S. EPA).  1989.
   B. Susceptibility and Status of South Atlantic Estuaries to Nutrient Discharges.
   NOAA/U.S. EPA. 1989.
   D. Susceptibility and Status of Gulf of Mexico Estuaries to Nutrient Discharges.
   NOAA/U.S. EPA. 1989.
   E. Susceptibility and Status of West Coast Estuaries to Nutrient Discharges.
   NOAA/U.S. EPA. 1989.
   4. National Estuarine Inventory: Physical and Hydrologic Characteristics.  NOAA
   Unpublished Data
                                                                                                                                                          I'aee Y

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Index of Watershed Indicators Phase 2 - Plans for the Future

The information contained in this publication presents the first nationwide index representing the condition and vulnerability of water quality in the
watersheds of the continental United States. In  Phase 2 of the Index of Watershed Indicators, we will be improving the information for the 15 indicators,
and adding additional indicators we were not able to include during Phase 1. Phase 2 begins in Summer 1997 and will work to include information on:

Geographic Areas
•            Add Alaska and Hawaii
•            Add specific information for Native American lands
•            Add information about Federally-owned lands
•            Work with USGS to correct Cataloguing Unit problems uncovered during the IWI process such as duplicative watershed names and boundary issues,
             work with NOAA to correct remaining inconsistencies between NOAA's Coastal Assessment Framework and USGS's Cataloguing Units.

Add Additional Indicators
•            Biological integrity
•            Habitat
•            Groundwater
«            Coastal condition (eutrophication and shellfish contamination)
*            Air deposition

Natural Processes
•            Take account of downstream effects, to capture where a watershed is simply exporting its pollution downstream to another watershed

Surf Your Watershed
•            Continue to add additional information to the Internet program "Surf Your Watershed," Users are encouraged to add data to "Surf so it can serve as
             the electronic index to all available  water quality information (the Internet address is: http://www.epa.gov/surf),

Partners
•            Work with data owners and other partners to correct problems identified during the review period that were not addressed during Phase I (e.g. missing
             reservoirs in Hydrologic Modification indicator), and add data to both IWI and "Surf Your Watershed"

Monitoring and Information Management

•            Work with partners to strengthen monitoring and information management systems that supply data for the Index The National Water Quality
             Monitoring Council (formerly the Intergovernmental Task Force on Monitoring  Water Quality) will be a key partner in this effort.
                                                                                                                                    Page 38

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                                                    Supplemental Maps

Three of the Index of Watershed Indicators data layers -- Map 3: Indicators of Source Water Condition for Drinking Water Systems, Map 7:
Wetland Loss Index  1780 - 1980; 1982 - 1992, and Map 12: Index of Agricultural Runoff Potential -- are aggregates of other maps, each
included here as supplemental maps.

Other IWI data layers are also aggregates of information. Readers are urged to review the Internet site "Surf Your Watershed"
(http://www.epa.gov/surf) to see the data that was used in making each of the maps in the Index of Watershed Indicators,
                                                                                                                     Page 39

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                                        3a.  Rivers and Lakes Supporting
                                               Drinking Water I'ses
                                                      1994/1996
Analysis of Alaska and
Ha\\aii it-served tor Phase 2
Percent of Watershed River and Lakes .Assessed
under Clean Water Act Section 305(b) Meeting
Drinking Water Designated Uses
  ^ SO - 100° o Meet Drinking Water Use
|    | 50 - 79° o Meet Drinking Wate Use
  ^ <50° o Meet Drinking Water Use
[T7v] Insufficient .Assessment Coverage.
     or No State Drinking Water Use Designated
  Index of Watershed
       Indicators
Source: U.S. Environmental Protection Agency
                                              June 2Q I

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Map 3 a
Importance of Rivers and Lakes Supporting State Drinking
Water Uses

The drinking water use assessments provided by the States under the Clean
Water Act's Section 305(b) are one of the three data sets used to
characterize source water condition. Water Quality Standards adopted by
the states include both designated uses and criteria to protect those uses.
Drinking water is one of the uses that can be protected.  States and Tribes
describe water quality in terms of a waterbody either fully supporting,
threatened, partially supporting, or not supporting the drinking water
designated use.

The percent of assessed waterbodies in a watershed meeting their drinking
water designated use is a partial proxy for the condition of the source waters
used by drinking water systems.  It is an indicator of how well drinking
water uses are protected by surface and ground water quality standards
promulgated through the Clean Water Act.  Section 305(b) designated use
assessments cannot, however, represent the full source water assessments
authorized by the Safe Drinking Water Act Amendments of 1996,

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your
Watershed" at: . Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses.

Data  Sufficiency Thresholds
Any data reported by States in their 305(b) reports were used in assessing
drinking water use support.

Notes on Interpreting this Information:
•       Data Somewhat Consistent/Additional Data Needed
         See "Plans to Improve this Data Layer for details.
•       The data set containing State assessments for drinking water use is
         incomplete either because some States did not designate or assess
         their  waters for drinking water use,  or they assumed that other
         uses that were assessed sewed as surrogates for drinking water
         use attainment.
•       Drinking water assessments are inconsistent across states.
        States and Tribes do not have identical water quality standards
        or identical methods or criteria to assess their waters.
•       Most States and Tribes do not assess all of their waters during the
        two-year reporting period, and they may even modify techniques
        used or assess different waters every two years.

Plans to Improve this Data Layer
EPA has several initiatives underway to improve the quality of the 305(b)
data to assess drinking water use:
•       EPA is working with States, Tribes, other federal agencies, and
        other partners to develop a more consistent approach to assessing
        both ground waters and surface waters for drinking water use.
•       EPA is also working with its partners to achieve comprehensive
        coverage of the waters in the nation in the 305(b) report, and
        include annual electronic updates of key data elements
•       This indicator will be  updated using the 1996 and subsequent
        database updates as they become available

For More Information Contact:
Database Owner:
US EPA, Office of Wetlands, Ocean and Watersheds
Individual Contact:
Carl Reeverts; E-mail: Reeverts.Carl@epamail.epa.gov
Phone: (202) 260-7273
Data Source:
1. National Water Quality Inventory: 1994 Report to Congress
        U.S. Environmental Protection Agency, Office of Water
        Washington, D.C. December 1995.  EPA 841-R-95-005
2. Waterbody System, 305(b) Cataloguing Unit Dataset, Version 1.0
        U.S. EPA, Office of Water. 1994, 1996

Additional Information
For additional information on specific state 305(b) reports contact U.S.
EPA's Barry Burgan at (202) 260-7060.
                                                                                                                                      Page 41

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                                                  3b. Surrogates of
                                               Source Water Condition
                                                       1991 -1996
Analysis of Alaska and
i la\\aii reserved tor Phase 2
Percent of Population Served by Community Water Systems
in Watersheds with Violations or Treatment in Place for
Chemical Contaminants
|    | 0 - 10°/o of Population Served by Community Water Systems
  ^] 11 - 50% of Population Served by Community Water Systems
  ~j >50% of Population Served by Community Water Systems
EggE) Data Sufficiency Threshold Not Met
  Index of Watershed
        Indicators
Souns: U.S. Environmental Protection Agency
     Safe Drinking Water Mormation"Sysiern
June 21, I -

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Map3b
Importance of Surrogates of Source Water Condition
Safe Drinking Water Information System (SDWIS) surrogate indicators provide one of
the three data sets used to characterize source water condition Map 3.  Water systems are
major users of the water resources and have a continual interest in the quantity and
quality of their water supplies.  Source water characterizations prompt water systems to
take corrective actions to prevent or respond to violations (including adding additional
treatment) to ensure that the water provided at the tap to consumers meets all drinking
water standards. Indicators developed from the existing SDWIS water system inventory
and violation data are used to flag situations where water systems have or will take
actions because of actual or threatened source water problems. Actions taken by water
systems can be a good surrogate for source water characteristics that may not be
identified through other data sources.

Two indicators were developed from SDWIS data:
a) Population served by Community Water Systems that reported one or more violations
of national health-based drinking water standards during FY 1991 - FY 1996 for
chemical (not microbiological) contaminants that are source related (i.e. inorganic
chemicals, volatile organic chemicals, synthetic organics, and radio-nuclides);
b) Population served by Community Water Systems that have treatment in place in 1996
to remove chemical (not microbiological) contaminants that are source water-related.

Access  to Detailed Data
Access to  detailed data for each data layer is available through "Surf Your Watershed" at:
•'http://www.epa.gov/surf/IWI/data>. Click on the data  layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Data Sufficiency Thresholds
The drinking water data will be considered sufficient to  characterize the watershed only
where the population served by community water systems is greater than 50 percent of
the population that resides in the watershed.  Community water systems reporting no
chemical violations or treatment in place for chemical contaminants were not included in
the source water assessment  (see "Notes on Interpreting this Information")

Notes on Interpreting this Information
 *        Data Somewhat Consistent/Additional Data Needed
         See  "flans to Improve this Data Layer  for details.
 »        Water svstems with  violations of microbiological standards  or treatment to
         address microbiological contaminants are not included in this data set.
 *        The use of violations data from SDWIS as a surrogate indicator to
         characterize source water condition has limitations
          - Absence of a violation is not to be construed as a statement on the
         quality of the source waters (i.e., water systems will take whatever actions
         neccssuiy to comply with drinking water standards at the tap);
         - Isolations may be  the result of water purchased outside the watershed or
         othenvise unrepresentative of watershed quality (e.g., from a confined
         aquifer)
•       The use of treatment objective data from SDWIS as a surrogate indicator
         to characterize source water condition has limitations:
         - SDWIS data on treatment objectives is not currently a required State
         reporting item and is therefore very incomplete, subject to different
         interpretations by the States, and potentially of lower quality than required
         elements;
         - Absence of data showing treatment for source water-related
         contaminants is not to be construed as a statement on the quality of the
         source waters because the data from SDWIS is known to  be incomplete.


Plans to Improve this  Data Layer
1)  SDWIS is undergoing a major modernization effort to improve data entry and
retrieval and to broaden  the accessibility of SDWIS  data to new and different users.
2) On-going data quality initiatives will continue to improve the quality of data in
SDWIS.
3) The data reported into SDWIS by the states is  undergoing a review by an ongoing
Data Sharing Committee to better meet the need of users.

For More Information Contact:
Database Owner:
U.S. Environmental Protection Agency, Office of Ground Water and Drinking Water

Individual Contact
Carl Reeverts
202 260-7273
E-mail: Reeverts.Carl@epamail.epa.gov

Data Source:
Extract from the Safe Drinking Water Information System (SDWIS), 1996.
SDWIS is a repository of information on the public water systems regulated by EPA
and the States under the Safe Drinking Water  Act.  Information on public  water systems
inventory and violations, as well as State and  EPA enforcement actions, are reported by
States to SDWIS on a quarterly basis. SDWIS information is used by EPA
Headquarters and Regions to support implementation and enforcement of the drinking
water program. It is also used to characterize progress of the regulatory program and
the effectiveness in terms of public health protection of the regulations. SDWIS is the
major source of information for the Agency environmental  indicators  initiatives related
to drinking water.
                                                                                                                                                             Page 43

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                       3c.  Occurrence of Chemicals in Surface and (Ground Waters
                                    that are Regulated in Drinking Water
                                                    1990-1995
/\nal\Ms 11) Alaska ajkJ
Itmrui reserved for Phase 2
Watershed Classification
  ^ <5° o of Samples that Exceed Half of MCL Levels
I    ] 5 - 25° o of Samples that Exceed Half of MCL Levels
  ^ -25% of Samples that Exceed HaJf of MCL Levels
KISt] Insufficient Data
  Index of Watershed
       Indicators
Souru.' I; S Environmoital Protection Agencs

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Map 3c
Importance of Occurrence of Chemicals in Surface and
Ground Waters That Are Regulated In Drinking Water

Occurrence of contaminants regulated under the Safe Drinking Water Act in (untreated )
ambient waters is one of the three data sets used to characterize source water condition in
watersheds  EPA maintains a national database, the STOrage and RETrieval (STORE!)
system, containing over 250 million observations of water quality monitoring data from
multiple sources both public and private, including the U.S. Geological Survey's
National Water Quality Assessment (NAWQA) data which has been added to the
STORE! system.

This data set includes sampling results in STORET from both surface water and ground
water points for all the chemical contaminants regulated under the Safe Drinking Water
Act. (See list of contaminants and their Maximum Contaminant Levels ( MCLs) in the
more detailed Data Profile for this data layer available on Internet at the address below.  )
 I he source of the data was limited to that provided by STORE! from  1990-1995
Observations above 50% of the MCL were summed for each watershed

The percent of samples that exceed half of the MCL levels  indicate the adequacy with
which drinking water may be protected by surface and ground water quality standards

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed"
at
•  hltp //www cpa.gov/surf/IWl/data>.  Click on the data layer of interest to find
documentation and  FTP (File Transfer Protocol) addresses.

Data  Sufficiency Thresholds
Each watershed must contain at least 5 observations representing a minimum of
five sites over the six year period, 1990-1995.

Notes on Interpreting this Information
•       Data Somewhat Consistent/Additional Data Needed
         Sec "Plans to Improve this Data Layer for details
•       Data were watershed-wide and not specifically related to source
         waters used by water systems, therefore,  this data should not be
         used to pinpoint actual source water impairment in the watershed.
•       7/7e current STORET .system contains limited information regarding
         data quality and STORET users do not necessarily use identical
         methods or criteria to assess their waters.
•       Most monitoring undertaken by States and Tribes is focused on rivers
        lakes and estuaries with suspected or identified pollution problems
        Assessments based on this type of monitoring may not be representative
        of the whole watershed and may overestimate the degree of concern.
•       STORET data is incomplete and may misrepresent the occurrence of these
        contaminants in the watershed  Many States have more complete data on
        ambient water quality for these contaminants

Plans to Improve this Data Layer
•       EPA is modernizing STORET to make it easier to access data; store
        information about data quality and equipment used to acquire the data;
        and expand the fields to store biological and habitat data.
•       EPA will look  into using information from the National Drinking
        Water Occurrence Database (NOCD) when it becomes available in
        August  1999.   It will contain information on the  occurrence of both
        regulated and unregulated contaminants in public waters systems.

For More Information Contact:
Database Owner: U.S. Environmental Protection Agency, Office of Water

Individual Contact:
Louis Hoelman
E-mail' Hoelman.Louie@epamail epa.gov
Phone 202260-7050

Data Source:
STOrage and RETrieval System (STORET), 1990-1995
        U.S. Environmental Protection Agency, Office of Water.

STORET is designed to collect and disseminate basic information on chemical,
physical and biological  quality of the nation's waters  It is a repository of waler
quality data, including information from ambient, intensive survey,  and effluent
water quality monitoring of the waterways within and contiguous to the U.S.

Additional Information
For additional information on STORET or data in STORE! , call the S I ORF I
  hotline at 1-800-424-9067
                                                                                                                                                      45

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                                    7a.  Wetland Loss Measured by the
                                       Natural Resources Inventory
                                                 1982 -1992
 Anahsis of Alaska and Hawaii
 resened tor Phase 2
Watershed Qassification
|    | Low Level of Wetland Loss
|    | Mxlerate Level of Wetland Loss
  ^) High Level of Wetland Loss
   Index of Watershed
        Indicators
Sources: Natural Resources Consen ition Service
                                                                                                    June 24, 19J7

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Map 7a
Importance of Wetland Loss Measured by the NRI
Wetlands make important contributions to the health of aquatic systems on a watershed
basis by purifying water, filtering runoff, abating floods, and decreasing erosion. In
addition, wetlands provide habitat for countless numbers of plants and animals including
over 40% of all federally listed threatened or endangered species.  Many wetland plants
and animals support recreation and commercial industries. For example, wetlands act as
nurseries for over 80% of coastal fisheries. In addition, millions of Americans are
annually drawn to wetlands for bird watching, hunting, fishing, and enjoying the natural
beauty of wetland ecosystems. Although wetland loss rates are slowing, the United
States continues to lose approximately 70,000 to 90,000 acres of wetlands on non-
federal, rural lands each year.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your Watershed"
at:
.  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.


Description of the Data Layer
Natural Resources Conservation Service (NRCS) reports on wetland acreage on rural,
non-federal lands that constitute about 75% of the Nation's land base-  (Reported at 6-
digit accounting unit)

  Using the  1992 NRI, watersheds were identified that had an 80 percent
probability or  greater of having a net wetland loss of more than 2 percent
over the 10-yeai period. Since the NRI is a sample, and not a census, estimates of
wetland acreage in 1982 and 1992 and percent wetland loss have errors associated with
them  These standard errors can be estimated from the sample data. The errors are
generally larger in watersheds with fewer NRI sample points, and in watersheds that have
diverse land cover. Assuming that the percent wetland loss for the NRI sampling units is
 approximately normally distributed, the probability that the true value exceeds a
 pre-determmed value can be calculated from the standard errors.

 Wetlands included all palustrine (inland) systems, estuarine systems with vegetation,
 non-vegetated estuarine systems classified as permanent open water less than 2 acres in
 size, riverine and  marine systems not also coded as permanent open water, vegetated
 lacustrine (lake) systems less than 40 acres, and non-vegetated lacustrine systems not
 also coded as  permanent open water.  Palustrine wetlands made up 93.9 percent and
 esluarinc wetlands made up 4.6 percent of all wetlands. Some wetlands went into federal
ownership betueen 1982 and 1992, and a small amount of federally owned wetlands
 were sold  Since  the NRI collects data on wetlands only on nonfederal land, it was
assumed thai the wetland status of these areas was not affected by changes in ownership
Data Sufficiency Threshold
All available data were used.

Notes on Interpreting this Information
•        Data Need to be Much More Consistent/Much Additional Data Needed.
         See "Plans to Improve this Data Layer" for details.
•        NRI data used in this analysis were adjusted to reflect differences and to
         account for some changes in NRCS's data collection methods. Unlike the
         other 14 IW1 data layers, these data were estimated at the 6 digit Accounting
         Unit scale (each 6 digit unit contains several 8 digit units). The IWl distributed
         the Accounting Unit estimates evenly to each of the component 8 digit
         Cataloging Units.
•        The NRI does not collect data on federal lands and data collection on tribal
         lands is not consistent.


Plans to Improve this Data Layer
1) U.S. EPA is working towards reporting on both the quantity and quality of wetlands.
However, wetland biological monitoring programs are still in  their infancy. As States
establish wetland monitoring programs and include this information in their 305(b)
reports, better data will be available for this data layer.

2) U.S. EPA is continuing to work with the USFWS and NRCS to monitor wetland loss
and report improvements in wetland acreage. The Federal Geographic Data Committee
Wetlands Subcommittee is exploring new approaches of tracking wetland acreage,
reporting more frequently, and reporting at the 8-digit watershed level.

3) U.S. EPA is looking at other sources  of data that could be used as an indicator of
wetland condition such as the increases  in impervious surfaces, and housing development
trends.

For More Information Contact:
Database Owners:
NRI:  USDA National Resources Conservation Service (NRCS)
Individual Contacts:
NRI:     Bob Kellogg
E-mail:  rkellogg@nhq.nrcs.usda.gov
Phone:   (202)690-0341
Data Source:
Natural Resources Inventory (NRI), 1982 and 1992

Additional Information
For additional information about the wetlands data layer, contact:
Tom Danielson, U.S. Environmental Protection Agency, Wetlands Division
E-mail:  Danielson.Tom@epamail.epa.gov  Phone: (202) 260-5299
                                                                       Page 47

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                                    7b. Wetland Loss Measured by the
                                       National Wetlands Inventory
                                                1780s - 1980s
 AnaKsis of Alaska and Hawaii
 reserved for Phase 2
Watershed Gassification
|    | Low Level of Wetland Loss
|    | IVbderate Level of Wetland Loss
    ] High Level of Wetland Loss
Index of Watershed
     Indicators
Source: U.S. Fish arel Wildlife Service
                                                                                                   June 24, 1997
                                                                                                             Ti 4-933SK

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Map7b
Importance of Wetland Loss Measured by the NWI

Wetlands have not always been recognized as important to aquatic system health.  In
times past, they have been intentionally drained and filled as land was developed, and as
a result, loss of wetlands has been substantial. The result has been loss of habitat and loss
of watershed capacity for flood retention. This information shows the extent of the loss
of this resource since Colonial times, and is a measure of the long-standing resource
reduction that threatens streams and rivers today.  The National Wetlands Inventory
plans, directs, coordinates, and monitors the gathering, analysis, dissemination, and
evaluation of information relating to the location, quantity, and ecological importance of
the Nation's wetlands.

Access to Detailed Data
Access to detailed data for each data layer is  available through "Surf Your Watershed"
at:
  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.


 Description of the Data Layer
The data used in the National Wetlands Inventory (NWI), 1780s-1980s) provides
 historical data from the U.S  Fish and Wildlife Service on wetland acreage on federal and
 non-federal lands. (State level)

 Data  Sufficiency  Threshold
 All available data were used.

 Notes on Interpreting this Information

 •       Data Need to  be Much More Consistent/Much Additional  Data Needed
         See "Plans to Improve this Data Layer" for details
 •       The historical NWI data were designed to track wetland change on a state-
         wide basis and, in most cases, do not provide robust watershed information.
 •       Unlike the other 14 IWI data layers, these data are reported at the 6 digit
         accounting unit scale (each 6 digit unit contains several 8 digit units), which
         IWI interpolated to the 8 digit area.
 •       Since NWI data are reported by state, the loss estimated for watersheds lying
         in two or more states may not reliably reflect the NWI historical data.
Plans to Improve this Data Layer

1. U.S. EPA is working towards reporting on both the quantity and quality of wetlands.
However, wetland biological monitoring programs are still in their infancy. As States
establish wetland monitoring programs and include this information in their 305(b)
reports, better data will be available for this data layer

2. U.S. EPA is continuing to work with the USFWS to monitor wetland loss and report
improvements in wetland acreage  The Federal Geographic Data Committee Wetlands
Subcommittee (which includes U.S. EPA, USFWS, NRCS, and other federal agencies) is
exploring new approaches of tracking wetland acreage, reporting more frequently, and
reporting at the 8-digit watershed level

For More Information Contact:
Database Owners:

NWI:  U.S. Fish and Wildlife Service (USFWS) Internet:  http //www.nwi fws gov/

Individual Contacts:
NWI-    Tom Dahl
E-mail:  Tom_Dahl@mail.fws.gov
Phone:  (813)570-5429

Data Source:

National Wetlands Inventory (NWI),  1780s-1980s


Additional Information
For information about wetlands, contact:
EPA Wetlands Information Hotline (contractoi operated)
1-800-832-7828  or httpV/www epa gov/OWOW/wetlands/wetline.html

For additional information about the wetlands data layer, contact:
Tom Danielson, U.S. Environmental Protection Agency, Wetlands Division
E-mail:  Danielson.Tom@epamail epa gov   Phone (202)260-5299
                                                                                                                                                            I'aec

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                                         12a.  Potential Pesticide Runoff
                                                from Farm Fields
                                                    1990-1995
Analysis ot Alaska and
1 tmaii reserved t'cT Phase 2
Watershed Classification
|    | Low Potential for Runoff
|    | Moderate Potential for Runoff
|    | High Potential for Runoff
gSS Insufficient IW1 Data
  Index of Watershed
        Indicators
Source: Natural Resources Conservation Sen ice

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Map 12a
Importance of Potential Pesticide Runoff from Farm Fields
Pesticide loss from farm fields is an important source of water quality
degradation in some watersheds. This indicator was developed to show which
watersheds have the greatest potential for the movement of agricultural pesticides
from farm fields through surface water runoff.  The indicator represents potential loss
at the edge of the field based on the factors that are known to be important
determinants of pesticide loss, including: 1) soils characteristics, 2) historical
pesticide use, 3) chemical properties of the pesticides used, 4) annual rainfall and its
relationship  to runoff, and 5) major field crops  grown in 1992. Watersheds with high
scores have  a greater risk of pesticide contamination of surface water than those with
low scores.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your
Watershed"  at: . Click on the data layer of
interest to find documentation and FTP (File Transfer Protocol) addresses.

Description  of the Data Layer
Using national-level databases, a simulation was conducted of potential pesticide
losses from representative farm fields. About 170,000 Natural Resources Inventory
(NRI) sample points were treated as ''representative fields." Thirteen crops were
included in the simulation: barley, corn, cotton, oats, peanuts, potatoes, rice,
sorghum, soybeans, sugar beets, sunflowers, tobacco, and wheat. The potential for
pesticide loss from each "representative field" was estimated using the  state average
pesticide application rate and percent acres treated from the National Pesticide Use
Database.  The maximum percent runoff loss over a 20-year simulation of rainfall
from the Pesticide Loss Database was imputed to NRI sample points using
match-ups by soil properties and proximity to 55  climate stations.  The total loss of
pesticides from each "representative field" was estimated by summing over the loss
estimates for all the pesticides that the National Pesticide Use Database reported for
each State and crop. Watershed scores were determined by averaging the scores for
the NRI sample points within each watershed

Data Sufficiency Thresholds
No data sufficiency threshold was applied.


Notes on  Interpreting this  Information
»      Data Consistent/Sufficient Data Collected
        See "Plans to Improve this Data Layer "for details.
•      The indicator measures only the potential for pesticides to run off farm
        fields,  ft does not estimate actual pesticide loss
 •      Research has shown that pesticide loss from farm fields can be
        substantially reduced by management practices that enhance the water
        holding capacity and organic content of the soil and reduce water runoff.
        Where these practices are being used, the potential loss measured by this
        indicator will be over-estimated.
 •      Pesticide loss from farm fields does not always translate to water quality
        impairment. Pesticides degrade during transport from the farm field to the
        water body. Dilution by runoff from non-cropland areas in the watershed
        will also reduce concentrations observed in surface water.
 •      The indicator does not include fruits, nuts, and vegetables. Watersheds
        with large acreage of these crops will have a greater risk  of water quality
        contamination than shown by this indicator.
 •      Estimates using the NRI report conditions on non-federal  rural lands. In
        watersheds with significant Federal or Tribal lands not inventoried in the
        NRI, estimates may not reflect the vulnerability accurately.

Plans to Improve this Data Layer
Research is underway to incorporate relative toxicity of the pesticides in the
aggregation scheme. The present  indicator treats all pesticides as equally risky
to the environment, even though some pesticides have lower "safe" thresholds
than others.

For More Information Contact:
Database Owner
Natural Resources Conservation Service, U.S. Department of Agriculture

Individual Contact
Robert Kellogg, NRCS/USDA
E-mail: robert.kellogg@usda.gov
Phone: (202) 690-0341

Data Source:
1. National Resources Inventory
        U.S. Dept.  of Agriculture, National Resources Conservation Service,
        1992
2. National Pesticide Use Database
        Gianessi, Leonard P., and James Earl Anderson. Pesticide Use in U.S.
        Crop Production: National Data Report. National Center for Food and
        Agricultural Policy, Washington D.C., February 1995.
 3.  Pesticide Loss Database
        Don W. Goss, Texas Agricultural Experiment  Station, Temple, Texas
                                                                                                                                                      Page 5 I

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                                          12b.  Potential Nitrogen Runoff
                                                  from Farm Fields
                                                      1990 -1995
            W
Analysis of Alaska and
Hawaii reserved for Phase 2
Watershed Classification
|    | Low Potential for Runoff
|    | Moderate Potential for Runoff
I    | High Potential for Runoff
  • Insufficient IWI Data
  Index of Watershed
        Indicators
Source: Natural Resources Conservation Service
                                              June 22,1997

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Map 125
Importance of Potential Nitrogen Runoff from Farm Fields
Nitrogen runoff from farm fields can contribute to eutrophication of downstream
waterbodies and sometimes impair the use of surface water for drinking water purposes.
This indicator was developed to show which watersheds had the greatest potential for
agricultural sources of nitrogen loadings to surface water. It represents potential nitrogen
runoff at the edge of the field based  on commercial fertilizer applications, uptake of
nitrogen by crops, potential nitrogen loadings from confined animal waste disposal, and
annual rainfall and its relationship to runoff.  Watersheds with the highest scores have a
greater potential of significant nitrogen loadings from agricultural sources than
watersheds with low scores.

Access to Detailed Data:
Access  to detailed data for each data layer is available through "Surf Your Watershed"
at: .  Click on the data layer of interest to find
documentation and FTP (File Transfer Protocol) addresses.

Description of the Data Layer
This indicator is a composite of two separate indices: a vulnerability index for the
potential for commercial fertilizer to run off from farm fields, and an index of the runoff
potential for manure nitrogen. The nitrogen commercial fertilizer index was constructed
using the National Resources Inventory (NRI) as a modeling framework. About 160,000
NRI sample points were  treated as "representative fields." Crops include corn, soybeans,
wheat, cotton, barley, rice, and sorghum.  A per-acre estimate of pounds of nitrogen
available for runoff at the edge of field was calculated as the difference between the rate
of application  per treated acre and the amount of nitrogen taken up by the harvestable
portion  of the  crop.  The amount of nitrogen taken up by the harvestable portion of the
crop was estimated by multiplying the percent of nitrogen in the grain times the county
per-acre average yield for 1988-1992. The vulnerability index was constructed by
multiplying the per-acre amount of nitrogen available for runoff by a runoff factor for the
two months following planting for each "representative field." The runoff factor was
based on rainfall and the curve number method of estimating surface runoff from a field
The average vulnerability index for all "representative fields" in a watershed was used to
characterize the potential for commercial fertilizer to run off from farm fields.

The runoff potential for manure nitrogen per watershed was based on manure loadings
derived from confined livestock inventories reported in the 1992 Agriculture Census
database  The total pounds  of nitrogen in manure was multiplied by an average
 12-month runoff factor for each watershed to create the index.

 The composite indicator was constructed by ranking the two indexes and summing the
ranks for each watershed.


Data  Sufficiency Thresholds
No data sufficiency threshold was applied.
Notes on Interpreting this Information
•        Data Consistent/Sufficient Data Collected.
         See  "Plans to improve this Data Layer" for details.
•        The indicator measures only the potential for nitrogen to run off farm fields  It
         does not estimate actual nitrogen runoff loss
•        Farm management practices are not included in the determination of the
         indicator. Research has shown that nitrogen loss can be substantially reduced
         by careful timing of nitrogen applications and management practices that
         reduce water runoff. Where these practices are being used, the potential loss
         measured by this indicator will be over-estimated.
•        Nitrogen loss from farm fields does not always translate to water quality
         impairment.  Dilution by runoff from non-cropland areas in the watershed will
         reduce nitrogen concentrations observed in surface water.
•        The index for commercial fertilizer applications only includes estimates for 7
         crops. Watersheds with large acreage of other  crops where commercial
         nitrogen fertilizer is applied will have a greater risk oj water quality
         contamination than shown by this indicator.
•        Estimates of manure loadings are not adjusted for animal waste treatment
         facilities (such as lagoons) although they are adjusted for storage losses and
         volatilization of nitrogen during application  Where animal waste treatment
         facilities are used, the indicator will over-estimate manure loadings
•        Estimates using the NRI represent non-federal rural lands. In watersheds with
         significant Federal or Tribal lands not inventoried in the NRI, estimates may
         not reflect the vulnerability accurately

Plans to Improve this Data Layer
Research is underway to more  precisely estimate nitrogen loss from farm fields, and to
include additional  crops.


For More Information Contact:
Database Owner:
U.S. Department of Agriculture,  Natural Resources Conservation Service
Individual Contact:
Robert Kellogg, NRCS/USDA
E-mail- robert.kellogg@usdagov
Phone: (202) 690-0341
Data Source.
  1.  National Resources Inventory, U.S. Department  of Agriculture, Natural Resources
         Conservation Service, 1992
  2  Nitrogen Use Statistics; U.S  Department of Agriculture, Economic
         Research Service
  3  Crop Yield Data; U S. Department of Agriculture, National Agricultural Statistics
         Service
  4.  Census of Agriculture, 1992, Bureau of the Census
                                                                                                                                                                 Page 53

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                                12c. Sediment Delivery to Rivers and Streams
                                       from Cropland and Pastureland
                                                   1990 -1995
            vy
Analysis of Alaska and
Hawaii reservedfcr Phase 2
Watershed Classification
|    | Low Potential for Delivery
[    | Ivfoderate Potential for Delivery
|    | High Potential for Delivery
    I Insufficient IWI Data
  Index of Watershed
        Indicators
Source: Nitural Resources Conservation Sen ice

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Map 12c
Importance of Sediment Delivery to Rivers and Streams
from Cropland and Pastureland

Soil eroding from agricultural land can be transported by water runoff to
rivers and streams and degrade the quality of surface water.  Carried with
this soil is organic matter which also degrades the quality of streams, rivers,
and estuaries. The potential for soil erosion varies from watershed to
watershed depending on the extent of agricultural land in the watershed,
rainfall amounts and intensity, soil characteristics, landscape characteristics,
cropping patterns, and farm management practices. These factors were
included in a national-level simulation model that was used to estimate the
amount of sediment delivered to rivers and streams in each watershed. The
simulation estimated sheet and rill erosion; gully erosion was not included.

Access to Detailed Data
Access to detailed data for each data layer is available through "Surf Your
Watershed" at:   Click  on the data
layer of interest to find documentation and FTP (File Transfer  Protocol)
addresses

Description of the Data Layer
The simulation was conducted as part of the Hydrologic Unit Modeling of
the  United States (HUMUS) project, which incorporates several
national-level natural resource and land use databases and a  variety of
process models in a Geographic Information System. The framework for
the  national simulation consists of the 2,11 I  hydrologic units in the 48
States.  Each hydrologic unit is divided  into  subareas according to the major
land uses. Up to 14 subareas per watershed  are available to  represent
cropland and pastureland (7 irrigated, 7 nonirrigated).  Soils characteristics
for  each subarea are taken from the STATSGO soils database.  A 30-year
weather  database is available for each watershed. A process model
incorporating hydrology, weather, sedimentation, crop growth, and
agricultural management (SWAT-Soil  and Water Assessment Tool) is
applied to each subarea to simulate the relationships among  rainfall, runoff,
IcaclimR, groundwater return flow, farm management practices, erosion,
and surface flow in rivers and streams.
SWAT is a continuous time model that operates on a daily time step for
each of the 30 years of the weather database.  One of the outputs of the
model is average annual sediment delivery to rivers and streams from sheet
and rill erosion from cropland and pastureland, as shown on this map.

Data Sufficiency Thresholds
No data sufficiency threshold was applied.

Notes on Interpreting this Information
•       Data Consistent/Sufficient Data Collected
        See "Plans to Improve this Data Layer  for details.
•       Sediment loads from nonagr(cultural land uses are not included in
        these estimates.  Estimates represent loadings delivered to rivers
        and streams, and do not represent in-stream loads. Gully erosion
        and channel erosion are also not included

Plans to Improve this Data Layer
The data and models used by HUMUS are continually updated and refined.
There are plans to improve sediment estimates by comparing model results
for in-stream loadings to actual loadings and adjusting the parameters of the
model where needed.  HUMUS will also be expanded to estimate sediment
loadings from nonagricultural areas and other sources of erosion.

For More Information Contact:
Database Owner:
Texas Agricultural Experiment Station, Temple, Texas
Individual Contact
Clive Walker, Texas Agricultural Experiment Station, Temple, Texas
E-mail: walker@brcsunO.tamu.edu
Phone:(817)770-6655

Data Source:
HUMUS  (Hydrologic Unit Modeling of the United States)
                                                                                                                                        Page 55

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Contacts for Further Information

Many individuals and organizations contributed information to and review of the Index of Watershed Indicators, and we thank them all. It has been a pleasure working
with so many dedicated and knowledgeable partners. For further information or to answer questions you may have, there are many contacts, some of which we list
below.

Surf Your Watershed:
As a first step to answer questions, we urge you if possible to go to the Internet program "Surf Your Watershed" at http://www.epa.gov/surf. Surf provides additional
information about each watershed in the Index of Watershed Indicators, individual contacts for particular kinds of data, more detailed background data (such as lists of
the specific fish advisories in effect in the watershed) and also links to much information in addition to the 15 indicators we used for the Index of Watershed Indicators
Internet also allows us to easily provide updated information in a way not possible in a published paper product. For further information on "Surf  call Karen Klima at
(202)  260-7087 (E-mail KIima.Karen@epamail.epa.gov)

If you do not find the information you need on "Surf Your Watershed," you can call the following:

The Index of Watershed Indicators process:
Sarah Lehmann at EPA Headquarters on 202 260-7021 (E-MAIL Lehjnann.Sarah@epamail.epa.gov)

Index of Watershed Indicators.
o   Overall assessment of data: Charles Spooner,  EPA Headquarters on (202) 260-1314 (E-MAIL Spooner.Charles@epamail.epa.gov)
o   Contacts for each indicator are listed on the individual maps

Monitoring Information:
Call 202 260-7040 and ask for the Monitoring Publications List.

Regional Contacts: Each EPA region has an Index of Watershed Indicators contact who can answer your questions or direct you to the right source:

Region I: Irish Garrigan 617 565-4728          Region 2: Larry Rinaldo  212637-3820          Region 3: Stuart Kerzner 215566-5709
CT, ME,  MA, NH, RJ, VT                        NJ, NY, PR, VI                                DE, DC, MD, PA, VA, WV

Region 4: David Melgaard 404562-9265         Region 5:  Tim Henry 312 886-6107              Region 6: Charlie Howell  214665-8354
AL, FL, GA, KY, MS, NC, SC, TN                IL, IN, MI, MN, OH, WI                         AR, LA, NM, OK, TX

Region 7: Julie Elfving  913551-7475            Region 8:  Jill  Minter  303 312-6084             Region 9:  Janet Hashimoto 415744-1933
IA,  KS, MO, NE                                 CO, MT, ND, SD, UT, WY                      AZ, CA, HI, NV, AS, GU

Region 10: Pat Cirone 206 553-1597
AK, ID, OR, WA
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