WEF Discussions — Now on LinkedIn!

WEF is pleased to announce the creation of free LinkedIn groups associated with its technical discussion forum topics. Through these LinkedIn groups, members will be able to view and participate in discussions, as well as communicate with one another via direct messages. Share your experiences and knowledge, ask questions and respond to other discussions as frequently as you like!

You must have a LinkedIn profile to join a LinkedIn group; you can create your profile here. If you already have a LinkedIn profile, all you need to do is submit a request to join one or all of the following groups:

Water Environment Federation (Main) | Biosolids | Collection Systems | Nutrients | Stormwater 
Utility Management | Water Reuse | Water for Jobs | Watershed Management | Laboratory Practices 

RSS Feed Print
Generic Control Limits for RPD and Standards
Posted: Monday, December 6, 2010 9:36 AM
Joined: 12/6/2010
Posts: 1

Are there any EPA guidelines for generic control limits for RPD and control standards?  If yes, could you please provide the site?

Posted: Monday, December 6, 2010 12:19 PM

Generic control limits are pretty much a thing of the past.  It used to be, a rule of thumb for inorganics/conventionals was + 20% RPD for precision and 75-125% recovery on spikes.


Now, it's best to get control limits from the individual methods.  Compilations exist, but are defined for use in specific context, such as the contract laboratory program.


That being said, there's a nice table called "10.0 Apendix E - Quality Control-Acceptance Criteria" for methods in 40 CFR 136, Table 1.  It's in a document titled "Protocol For EPA Approval of Alternate Test Procedures for Organic and Inorganic Analytes in Wastewater and Drinking Water, March 1999, EPA 821-B-98-002."


There may be other compilations, but I couldn't find them quickly in our library.  Hope this helps.


Chuck Lytle