Skip common site navigation and headers
United States Environmental Protection Agency
National Pollutant Discharge Elimination System (NPDES)
Begin Hierarchical Links EPA Home > OW Home > OWM Home > NPDES Home > Proposed Sufficiently Sensitive Methods Rulemaking End Hierarchical Links
Applications
 
eNOI
 
Permitted Universe and Backlog Reduction
 
State Program Information
 
Statutes and Regulations
 
Tools for Permit Writers
 
Water Quality and Technology-Based Permitting
 
Integrated Municipal Plans
 
Emerging Topics
 
 
 
NPDES Permit Program Basics Home

 

NPDES Topics Alphabetical Index Glossary About NPDES

Proposed Sufficiently Sensitive Methods Rulemaking

NPDES: Use of Sufficiently Sensitive Test Methods for Permit Applications and Reporting

The EPA is proposing minor amendments to its Clean Water Act (CWA) regulations to codify that under the NPDES program, only "sufficiently sensitive" analytical test methods can be used when completing an NPDES permit application and when performing sampling and analysis pursuant to monitoring requirements in an NPDES permit.

This proposal is based on requirements in the CWA and existing EPA regulations. It also would codify existing EPA guidance from the 2007 memorandum, "Analytical Methods for Mercury in NPDES Permits (PDF) (4 pp, 39KB)," from James A. Hanlon, Director of EPA's Office of Wastewater Management, to the Regional Water Division Directors on the use of "sufficiently sensitive" analytical methods with respect to measurement of mercury and extend the approach outlined in that guidance to the NPDES program more generally. Specifically, EPA is proposing to clarify the existing NPDES application, compliance monitoring, and analytical methods regulations. The amendments in this proposed rulemaking affect only chemical-specific methods; they do not apply to the Whole Effluent Toxicity (WET) methods or their use.

EPA has generally approved multiple analytical test methods for CWA pollutants under 40 CFR 136 and 40 CFR Chapter I, Subchapters N and O. Some of the approved analytical test methods have greater sensitivities and lower minimum levels or method detection limits (MDLs) than other approved methods for the same pollutant. This situation is often due to advances having been made in instrumentation and in the analytical protocols themselves.

EPA and state permitting authorities use data from the permit application to determine whether pollutants are present in an applicant's discharge and to quantify the levels of all detected pollutants. These pollutant data enable the director of the permitting authority to make a sound reasonable potential determination and, if necessary, establish appropriate permit limits. It is critical, therefore, that applicants provide data that are measured with a precision and accuracy that will be meaningful to the decision making process. The same holds true for monitoring and reporting relative to permit limits established for regulated parameters.

The purpose of this proposal is to clarify that NPDES applicants and permittees must use analytical methods that are capable of detecting and measuring the pollutants at, or below, the respective water quality criteria or permit limits.

On June 23, 2010 EPA issued a Federal Register Notice (PDF) (9 pp, 95KB), announcing the proposed amendments to the CWA regulations, and the public will have 45 days to comment on the proposed rulemaking.

Please contact Kathryn Kelley of the State and Regional Branch, Water Permits Division, at 202-564-7004, with any questions regarding this regulatory revision.

National Pollutant Discharge Elimination System Home

NPDES Permit Program Basics Information
Recent Additions

FAQs

Publications

Regulations

Training & Meetings

Links

Contacts

 
 Register to Receive NPDES News Alerts!  

You will need Adobe Reader to view some of the files on this page. Files are best viewed in Internet Explorer and Adobe 8.0 or higher. See EPA's PDF page to learn more.

 

Office of Water | Office of Wastewater Management | Disclaimer | Search EPA

Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us

Last updated on June 24, 2010 1:14 PM
URL:http://cfpub2.epa.gov/npdes/ssmethods.cfm