Nonpoint Source Assessment: User's Guide to Ohio's Surface Waters

Bulletin 873-98

Using the Nonpoint Source Assessment

The following section of the User's Guide explains how to obtain NPS assessment information for Ohio streams, public lakes, and ground water areas. The appendices following this section provide important information that is referenced in the text. Appendix A is a list of definitions for water quality monitoring and assessment terms. Appendix B is a map of Ohio's 88 county boundaries and 93 major watersheds (called "Hydrologic Groups"). Appendix C is a listing of the names of these 93 Hydrologic Groups. Appendix D is a list of county names and the Hydrologic Groups that overlap each county boundary. Appendix E is a list of public nonpoint source impacted lakes and their acreage. Appendix F contains information on how to order reports and obtain helpful documents. A map of Ohio EPA districts and district office contact information is provided on the back cover.

Streams

NPS information for streams can be obtained over the internet or by contacting Ohio EPA district offices. Streams within Hydrologic Groups are divided into segments. Segments are usually portions of the stream extending from one tributary confluence to another. NPS assessment information is provided for stream segments and includes an evaluation of how attainment is affected by NPS pollution. Impaired streams are those failing to attain their aquatic life use designation. Impacted streams are affected by nonpoint source pollution, but it has not been determined whether or not they are attaining their aquatic life use designation. Threatened streams are presently attaining their aquatic life use designation, but the possibility exists for future impact from NPS pollution. An example of the type of information available for a stream segment is shown in Table 1.

To obtain current NPS information for a stream segment, access the internet using the following address:

http://chagrin.epa.ohio.gov/watershed/findit.html

At this address, you will find an interactive map. Simply click the mouse on the location of the stream, town, county or watershed and select the series of "buttons" that allows you to view use attainment information and NPS survey information for the stream segment of interest. You can view the information on your computer screen or download the report as a text file. The illustration in Figure 1 is a sample Hydrologic Group map with labeled stream segments, and county and watershed boundaries. It is typical of what you will find at the Ohio EPA internet site.

Figure 1. A Hydrologic Group map of the Upper Sandusky River watershed.
The dark lines are numbered stream segments for which NPS assessment survey
data are available.

If you do not have internet access, contact your Ohio EPA district office and provide them with the name or number of the Hydrologic Group of interest, and the portion of the stream you are investigating. You can reference the appendices in this User's Guide to locate your Hydrologic Group by county location or name.

Another useful source of information might be the original Ohio Nonpoint Source Assessment document completed in 1990. The 1990 Assessment includes a state overview; information on assessment procedures; levels of impairment of streams, lakes and ground water; and sources of impairment for each major river system. However, the original Assessment will not include the most recent monitoring and assessment data, and information on causes and sources of impact.

Step-by-Step Procedure for Streams

The following is a step-by-step process for accessing the results of Ohio's NPS Assessment of streams:

1. Knowing the name of the county in which the stream is located, reference Appendix B or Appendix C and determine the appropriate Hydrologic Group number for the stream of interest, or reference the internet address and find your Hydrologic Group;

2. At the internet site, download the NPS assessment report for the stream segment(s) of interest, or, if using this guide, determine the Ohio EPA district office in which the Hydrologic Group is located by referencing the back cover; and

3. Contact the Ohio EPA district office, provide Hydrologic Group number and ask for related NPS assessment information.

The Ohio EPA contact can assist you in locating numbered stream segments if the names or locations of stream segments of interest are unknown.

Lakes

Recent use attainment information for lakes larger than 5 acres is provided in the Ohio Water Resource Inventory, Volume III: Ohio's Public Lakes, Ponds & Reservoirs. Information for obtaining Volume III published by Ohio EPA is found in Appendix F. The four possible use designations for a lake include: the aquatic life habitat use of Exceptional Warmwater Habitat (EWH), the water supply use of Public Water Supply (PWS), and two general use designations applied to lakes: Recreation (REC), and Fish Consumption (FC). Levels of use attainment include: full use/full attainment (F); threatened use/full attainment (T); partial use/non-attainment (P); impaired use/non-attainment (I); and insufficient data (U).

Many of Ohio's lakes have multiple uses and may show partial use support or impairment for one use but full use for another. The Ohio EPA uses a multi-parameter lake classification procedure called the Ohio Lake Condition Index (Ohio LCI) to determine level of use attainment.

Table 2 is an example of the use attainment information available in the Ohio Water Resource Inventory, Volume III for a lake impacted by NPS pollution.

1. If the name of the public lake or the exact location of the lake is unknown, contact the appropriate Ohio EPA district office shown on the back cover of this User's Guide and ask for information; or,
2. If the name of the public lake is known and if the lake is greater than five acres in size, reference Appendix E to determine if the lake has been identified as impacted by nonpoint source pollution as of 1998;
3. To determine the lake's use attainment status for any of the four possible uses (exceptional warmwater habitat, public water supply, recreation, and fish consumption) and Ohio LCI parameter status, reference the Ohio Water Resource Inventory, Volume III: Ohio's Public Lakes, Ponds & Reservoirs.

Ground Water Areas

NPS information for ground water areas is not available in any one comprehensive report, instead, databases are maintained by staff at Ohio EPA district offices. Ground water information related to point and nonpoint sources is maintained on a county and township basis. For information on ground water pollution, contact the appropriate Ohio EPA district office and ask for the district staff in the Division of Drinking and Ground Waters. To help the staff locate information specific to your needs, provide the name of the county, township, city and/or village.

For information about a specific well, contact the Ohio Department of Natural Resources (ODNR), Division of Water, Water Resources Section. The staff of the Water Resources Section maintain a well-log database with records on over 700,000 Ohio wells. To obtain a copy of the well-log of the well of interest, provide the name of the county, township, city and/or village. Also, provide the name of roads and a major intersection near the well, and any current or past landowner, if available.