Diamond Lake IA 03-NSK-861
Poweshiek County S2T78NR15W approx 2.5 mi SW of Montezuma.
Assessment Comments
Assessment is based on results of water quality monitoring and surveys of the DNR Fisheries Bureau.
Basis for Assessment
The assessments of support of the Class B(LW) aquatic life uses developed for the 1994 and 1996 reports were reviewed and approved by the DNR Fisheries Bureau. Thus, the Class B(LW) uses remain assessed as FST. Continue to assess support of the Class C (drinking water) uses as FST based on assessments developed for the 1994 and 1996 reports. The Montezuma Municipal Water Supply issued a drinking water advisory for cyanazine in June 1996 due to a level (1.88 ug/l) that exceeded the U.S. EPA lifetime health advisory level of 1 ug/l. Health advisory levels are non-enforceable; cyanazine is not regulated under the federal Safe Drinking Water Act; the Iowa Water Quality Standards do not specify an MCL for this pesticide.
Assessment Key Dates
Methods
| 340 | Primary producer surveys (phytoplankton/periphyton/macrophyton) |
| 120 | Surveys of fish and game biologists/other professionals |
| 222 | Non-fixed-station monitoring (conventional during key seasons and flows) |
| 270 | PWS chemical monitoring (ambient water) |
Monitoring Levels
| Biological | 0 |
| Habitat | 0 |
| Physical Chemistry | 3 |
| Toxic | 0 |
| Pathogen Indicators | 0 |
| Other Health Indicators | 0 |
| Other Aquatic Life Indicators | 0 |
| # of Bio Sites | 0 |
| BioIntegrity | N/A |
| Causes | Use Support | Cause Magnitude | Sources | Source Magnitude |
|---|---|---|---|---|
| Atrazine | Drinking Water | Not Impairing |
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| Nutrients | Aquatic Life Support | Not Impairing |
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| Pesticides | Drinking Water | Not Impairing |
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