EPA documents- USEPA 1996, Puls and Barcelona; and USEPA 2002 Yeskis and Zavala.
When did the EPA first release information on low-flow.
Attached are the copies of the 1996 USEPA Groundwater Issue by Drs. Puls and Barcelona, and the 2002 USEPA RCRC/CERCLA groundwater sampling guidance document authored by Douglas Yeskis and Bernard Zavala.
The 1996 document was the earliest guidance from USEPA on the application of low-flow groundwater sampling. While we have learned a bit more about the practice since its publication, most notably in the area of drawdown and indicator parameter values, the basic principles outlined in the document are still very relevant.
The 2002 document, while it offers an overview of other sampling approaches and relevant background information, it incorrectly cites the 1996 publication as its basis for limiting the application of low-flow sampling to wells with screen or intake lengths of 10 feet or less. Discussions with both Drs. Puls and Barcelona clarified their intent, which was to advocate for shorter screen lengths wherever possible to target monitoring zones and reduce averaging effects during purging. A teleconference between Dr. Barcelona and Bernard Zavala in 2006 reinforced this, but to date, no revision of the 2002 document has been published.
Also attached is a 2005 paper from Groundwater Monitoring and Remediation, authored by Drs. Barcelona and Puls, that was written to specifically address the issues of drawdown and well screen length limits that remain uncorrected in the 2002 Yeskis and Zavala document.
Attached are the copies of the 1996 USEPA Groundwater Issue by Drs. Puls and Barcelona, and the 2002 USEPA RCRC/CERCLA groundwater sampling guidance document authored by Douglas Yeskis and Bernard Zavala.
The 1996 document was the earliest guidance from USEPA on the application of low-flow groundwater sampling. While we have learned a bit more about the practice since its publication, most notably in the area of drawdown and indicator parameter values, the basic principles outlined in the document are still very relevant.
The 2002 document, while it offers an overview of other sampling approaches and relevant background information, it incorrectly cites the 1996 publication as its basis for limiting the application of low-flow sampling to wells with screen or intake lengths of 10 feet or less. Discussions with both Drs. Puls and Barcelona clarified their intent, which was to advocate for shorter screen lengths wherever possible to target monitoring zones and reduce averaging effects during purging. A teleconference between Dr. Barcelona and Bernard Zavala in 2006 reinforced this, but to date, no revision of the 2002 document has been published.
Also attached is a 2005 paper from Groundwater Monitoring and Remediation, authored by Drs. Barcelona and Puls, that was written to specifically address the issues of drawdown and well screen length limits that remain uncorrected in the 2002 Yeskis and Zavala document.