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Ecological Sciences/Technical Resources - Water Quality

Ecological Sciences/Technical Resources - Water Quality

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Idaho Water Quality Technical Notes

Document Title Size
Water Quality Index   (PDF; 10 KB)
Tech. Note 2 A Procedure to Estimate the Response of Aquatic Systems to Changes in Phosphorus and Nitrogen Inputs (PDF; 29 KB)
Tech. Note 3 Waterborne Pathogens in Agricultural Watersheds (PDF; 11 KB)
Tech. Note 4 Nitrogen Transport Risk Assessment (PDF; 111 KB)
Tech. Note 5 Phosphorus Transport Risk Assessment: A Phosphorus Assessment Tool (PDF; 253 KB)
Tech. Note 6 Idaho Nutrient Transport Risk Assessment (INTRA): A Water Quality Risk Assessment Tool for Conservation Planning (PDF; 182 KB)
Tech. Note 7 Pesticide Environmental Risk Assessment Using WIN-PST Version 3.1 and Mitigating the Impacts of Pest Suppression – Procedures for applying WinPST 3.1 results to meet Practice Standard 595 – Integrated Pest Management. Detailed instructions for the Idaho Pest Management Planning Worksheet 2011 are also provided. (PDF; 87 KB)


The following documents require Adobe Acrobat.

EPA Construction General Permit


Green Manures and Water Quality
Potato producers in Idaho have been using synthetic soil fumigants to control soil-borne diseases and weed seeds.  Heavy reliance on these synthetic pesticides has contributed to groundwater contamination.  Certain soil-incorporated green manures, like oilseed radish and mustard, produce a compound that is toxic to soil fungi, nematodes, and weed seeds.  This biofumigation effect can help reduce the reliance on synthetic pesticides when green manures are used in the rotation.

Idaho Home*A*Syst is a voluntary, confidential program designed to assist homeowners/landowners with protecting their drinking water.  A series of worksheets and fact sheets are available that discuss a variety of potential resource concerns, with recommended precautions and protective practices.

Nitrate Priority Areas in Idaho
The 2008 Nitrate Priority Area ranking has identified 32 impacted areas in the state, up from the 25 originally identified in 2002.  The top priority area is Twin Falls, followed by Ada and Canyon Counties, Weiser, Fort Hall, and northeast Star.  For all Nitrate Priority Areas, at least 25% of sampled wells have nitrate-N levels at or above 5 milligrams per liter (mg/L).  The state and federal drinking water standard, as well as the Idaho Ground Water Quality Standard for nitrate-N is 10 mg/L.  Click on the link for additional information about each area, and their locations.

Water Quality Indicators Guide: Surface Waters (SCS-TP-161)  examines five major sources of agriculturally related nonpoint source pollution - sediment, nutrients, animal waste, pesticides and salts.  Field sheets are provided to enable the user to assess surface water quality problems easily and accurately and to select appropriate remedial practices. 

Idaho NRCS Water Quality Reference List  Updated!