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SDWA Perspective on Pesticide Monitoring
Oral Presentation
Prepared by A. Eaton
Eurofins Eaton Analytical, 750 Royal Oaks Drive, Monrovia, CA, 91016
Contact Information: AndyEaton@eurofinsUS.com; 626-386-1125
ABSTRACT
USEPA has been developing pesticide methods for drinking water analysis since the early 1990s. Most of the methods promulgated before the advent of the Unregulated Contaminant Monitoring Rules (UCMR1, UCMR2, UCMR3) were either GC or GCMS methods and were very prescriptive in nature. This was largely because the SDWA REQUIRES EPA to specify methods for compliance monitoring.
Beginning with the Contaminant Candidate List (CCL), and the start of monitoring programs under the UCMRs, EPA’s approach to pesticide monitoring under the SDWA evolved in multiple ways.
1) The drinking water program began utilizing LC-MS-MS methods to a much greater extent
2) There are more options built into the methods
3) Preservation & holding time studies are much more rigorous than in earlier methods
4) MRL determinations are much more rigorous, using the LCMRL concept
5) Reporting limits are being pushed down into the ppt range.
6) The drinking water program is revisiting some of the older methods and letting vendors assist with improvements, as long as there are multi-lab validations and LCMRL determinations.
Under the UCMR3 program, less than a dozen laboratories were able to gain approval for the more sophisticated methods, which did not even include pesticides. Multi lab validation studies for newer EPA drinking water pesticide methods have shown that some analytes are much more rugged than others, and because EPA is committed to ensuring that new drinking water methods can be used by a reasonably large number of labs, some of the newer methods are ending up with shorter analyte lists than EPA would probably like. As interest continues to evolve in lower and lower levels, the EPA drinking water program will also likely continue to evolve and use more advanced analytical techniques, such as direct injection LC-MS-MS and online pre-concentration, while still trying to ensure that these analytical methods are available to a sufficient number of laboratories.
Oral Presentation
Prepared by A. Eaton
Eurofins Eaton Analytical, 750 Royal Oaks Drive, Monrovia, CA, 91016
Contact Information: AndyEaton@eurofinsUS.com; 626-386-1125
ABSTRACT
USEPA has been developing pesticide methods for drinking water analysis since the early 1990s. Most of the methods promulgated before the advent of the Unregulated Contaminant Monitoring Rules (UCMR1, UCMR2, UCMR3) were either GC or GCMS methods and were very prescriptive in nature. This was largely because the SDWA REQUIRES EPA to specify methods for compliance monitoring.
Beginning with the Contaminant Candidate List (CCL), and the start of monitoring programs under the UCMRs, EPA’s approach to pesticide monitoring under the SDWA evolved in multiple ways.
1) The drinking water program began utilizing LC-MS-MS methods to a much greater extent
2) There are more options built into the methods
3) Preservation & holding time studies are much more rigorous than in earlier methods
4) MRL determinations are much more rigorous, using the LCMRL concept
5) Reporting limits are being pushed down into the ppt range.
6) The drinking water program is revisiting some of the older methods and letting vendors assist with improvements, as long as there are multi-lab validations and LCMRL determinations.
Under the UCMR3 program, less than a dozen laboratories were able to gain approval for the more sophisticated methods, which did not even include pesticides. Multi lab validation studies for newer EPA drinking water pesticide methods have shown that some analytes are much more rugged than others, and because EPA is committed to ensuring that new drinking water methods can be used by a reasonably large number of labs, some of the newer methods are ending up with shorter analyte lists than EPA would probably like. As interest continues to evolve in lower and lower levels, the EPA drinking water program will also likely continue to evolve and use more advanced analytical techniques, such as direct injection LC-MS-MS and online pre-concentration, while still trying to ensure that these analytical methods are available to a sufficient number of laboratories.