CWA Method Equivalency: What a Manufacturer Must Provide and What a Laboratory Must Have Onsite for the Auditor

Collaborative Efforts to Improve Environmental Monitoring
Oral Presentation

Prepared by

Contact Information:; 563-554-9450


With the promulgation of the 2007 Method Update Rule for 40 CFR part 136, the EPA Office of Water issued a memo (Richard Reding, Chief, Engineering & Analytical Support Branch, EAD, OST) that gave clear guidance on how to follow the change allowed for method flexibility under 40 CFR part 136.6. In the memo, clear responsibilities for the Developer were listed. Method Equivalency studies performed by test kit and supply manufactures (Merck KGaA and Environmental Express) will be presented and how each manufacturer addressed each point of Method equivalency for the laboratory’s records and auditor’s requirements under Clean Water Act regulations.