Re: [CPEO-MEF] Irvine Desalter/TCE remediation project

[bmolnaa@earthtech.com]

The California definition of an aquifer is more stringent than EPA's. By
requiring TDS to be no more than 3,000 mg/L, the state is ensuring that
drinking water is provided with a TDS of <3,000. The EPA definition of an
aquifer with TDS of no more than 10,000 mg/L ensures that drinking water is
provided with a TDS of <10,000. As a result, the EPA definition of an
aquifer is more liberal than California's.

There isn't much of a difference in the yield requirement.

I also wanted to comment on Doobage's remarks regarding natural
attenuation.
Although we may differ in our beliefs of whether or not natural attenuation
is a viable remedy for sites, I do agree with the comment that "the greater
percentage of natural attenuation remedies nationwide has not observed
those(the EPA's) requirements." I would encourage those in the regulatory
community to be aware of the EPA requirements and adopt them as minimum
standards for evaluating natural attenuation.


Date: Fri, 03 Aug 2001 17:00:40 -0700
From: petestrauss1@home.com
Subject: Re: [CPEO-MEF] Irvine Desalter/TCE remediation project


In reviewing a specific project at Moffett Field, I noted that EPA's
definition of "potential drinking water" includes groundwater with a
Total Dissolved Solids (TDS) concentration of 10,000 mg/L or less, and
an average yield of 150 gallons per day (gpd), as compared with the
California State Water Board's definition of TDS at 3,000 mg/L or less
and an average yield of 200 gpd. That means that in terms of defining
potential drinking water, the federal government is more stringent than
California, and covers a wider swath of groundwater.  EPA's definition
trumps California's until the state has an EPA-endorsed Comprehensive
State Groundwater Protection Program.

Peter

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