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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

NPDES Wastewater & Stormwater Permits

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Permit Writers' Manual


EPA Pacific Southwest Region draft guidance for permitting NPDES discharges into impaired water bodies in the absence of a TMDL

The following draft guidance interprets the existing federal regulatory requirements concerning NPDES permits and provides additional guidance on requirstate relatedements. After it is completed, the guidance will provide helpful information to assist in development of NPDES permits in Region 9 when Total Maximum Daily Loads (TMDLs) have yet to be developed.

For questions or information concerning the guidance, please call Doug Eberhardt (eberhardt.doug@epa.gov) at (415) 972-3420

EPA Region 9 and 10 Guidance for Implementing Whole Effluent Toxicity Testing Program

U.S. EPA Regions 9 and 10 have jointly developed draft whole effluent toxicity (WET) implementation guidance for NPDES permit writers.  This 1996 guidance document provides an introduction to WET implementation in the NPDES permitting program taken from federal NPDES regulations, EPA guidance documents for permit writers, and toxicity test methods manuals.  Procedures for evaluating reasonable potential and setting WET permit limits are described with examples; basic toxicity test method statistics and quality assurance are reviewed; and toxicity reduction evaluations are discussed.  Sample WET permit language is also provided.  This document is not a substitute for EPA, or State or Tribal regulations and policies governing WET.  

For more information contact Robyn Stuber (stuber.robyn@epa.gov) or (415) 972-3524

EPA Memo on Which Stormwater Infiltration Practices/Technologies Have the Potential to be Regulated as “Class V” wells by the Underground Injection Control Program

Stormwater infiltration has become an increasingly effective tool in the management of stormwater runoff.  Although primary stormwater management responsibilities within EPA fall under the Clean Water Act, the infiltration of stormwater is, in some cases, regulated under the Safe Drinking Water Act.  Surface and groundwater protection requires effective integration between the overlapping programs.  There are cases where stormwater infiltration practices are regulated as Class V wells under the Underground Injection Control (UIC) program.  Most ‘green infrastructure’ practices do not meet the Class V well definition and can be installed without regulatory oversight by the UIC Program.  This memo contains a guide to identifying which stormwater infiltration techniques meet the UIC Class V well definition.


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