RSA 485-A:12 (Water Pollution Control Act) requires clean-up of pollution sources that contribute to violations of water quality standards. DES maintains a list of impaired waters that do not meet water quality standards and need clean-up. In the interim between the time waters are listed as impaired and the time a clean-up plan (TMDL) is prepared, no additional pollutant loading that would contribute to the impairment is allowed. Therefore, new activities in areas where stormwater would contribute to violations of water quality standards are required to include Best management Practices (BMPs) for stormwater pollution control so that pollutant loading from the new activity is no greater than the pre-existing loading, and so that new activities do not exacerbate an existing water quality violation.
Individual 401 Water Quality Certification (Certification) addresses impaired waters during the individual 401 Certification review process. However, the generic 401 Certification (No. 2007-003), issued for the US Army Corps of Engineers New Hampshire State Programmatic General Permit, does not necessarily address impaired waters and may require modification relative to impaired waters.
Click on the county list links to view maps of impaired waters by county.
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