Clean Water Act updated analytical methods

The U.S. Environmental Protection Agency (EPA) periodically updates analytical methods for environmental laboratories under the Clean Water Act. Our team accredits these laboratories in Washington state.

Clean Water Act methods update now in effect

The most recent CWA Method update rule went into effect on Sept. 27, 2017. We began accrediting labs for the latest approved methods immediately after the rule took effect.
Changes include:

  • New and revised methods including the new EPA 600 series methods
  • Updated versions of currently approved methods
  • Methods reviewed under the alternative test procedure (ATP) program
  • Clarifications to ATP approval procedures
  • Revised method detection limit (MDL) procedure

The new 600-series methods

  • 608.3 for organochlorine pesticides and PCB Aroclors with GC/MS, replaces Method 608
  • 624.1 for volatile (purgeable) compounds by GC/MS, replaces Method 624
  • 625.1 for base/neutrals and acids by GC/MS, replaces Method 625

Methods Update Rule-2017 at the Environmental Protection Agency describes the changes in detail.

Changes at renewal and after

Scopes have already been updated for all new methods except the new 600-series methods. We now automatically update scopes to the new 600 series methods at renewal. We expect labs to have updated their Standard Operating Procedures and proficiency tests to the new methods. You will have to perform Initial Demonstrations of Capability (IDCs) for the new methods and should perform initial minimum detection limit (MDL) analysis using the new MDL procedure.

Third-party and directly accredited labs may differ in status

If you have third-party accreditation, you should have an updated third-party scope. 

Labs with updated third-party scopes that do not provide documentation of an audit by their primary accrediting body for the new 600-series methods will be accredited with interim status.

Directly accredited labs that have not fully updated by renewal time will be accredited with interim and provisional status.

All labs will be given one year from their renewal date to update to the new 600 series methods. Labs not updated by that time will be denied accreditation for those methods.