Methods and Biological Update Rules

On March 12, 2007, the Environmental Protection Agency (EPA) promulgated the Methods Update Rule (MUR). This rule removes old EPA methodology and approves more recent methodology for drinking water and wastewater methods found in 40 CFR Parts 141 and 136 respectively. The following links provide more information on these rules as well as links to the rules themselves.

Methods Update Rule (MUR) - March 12, 2007

Biological Update Rule - March 26, 2007

EPA Clarification letter: The EPA issued a letter regarding the flexibility allowed at 40 CFR Part 136.6 To view that letter in pdf, click here.

Standard Methods 21st Edition and On-Line Standard Methods: The EPA has issued a memorandum documenting the approved methods in the 21st edition of Standard Methods and the equivalent On-Line Standdard Methods. To view this letter, click here.

EPa has set-up a Frequently asked questions page to help with some of the new provisions in the Methods Update Rule. Please see the link below to access that page.

EPA's Frequently Asked Questions

EPA has also set-up a special e-mail address to answer questions regarding the methods. That address is OSTCWAMethods@epa.gov.