Addendum to serious well contamination at MCAS, El Toro, Ca.

[zweifel@nexus.chapman.edu]

From: Don Zweifel <zweifel@nexus.chapman.edu>
Subject: Addendum to serious well contamination at MCAS, El Toro, Ca.

To David Keith and all interested parties:

Regarding Trichloroethylene or TCE, the MCL is actually 5 micrograms/l 
or 5 ppb rather than 5 milligrams/liter or 5 ppm.

TCE is considered a priority pollutant by the USEPA and is moderately 
volatile and biodegradable. Its solubility is 1100 mg/l which is 
moderately high. The biochemical decay coefficient is moderate in 
comparison to most other priority pollutants. The risk to human health (is 
calculated as times 10 to the minus six) for water and fish 
ingestion at 2.7 ppm and fish ingestion only, at 80.7 ppm. The EPA has 
determined that it is a carcinogen.

Its toxicity characteristics for contaminated soil at a maximum allowable 
concentration is 0.5 mg/l or 0.5 ppm (source: USEPA, Federal Register 29 
March, 1990).

Solute (solution) transport or its ability to hydraulic through the 
layers of permeable and semi-permeable soils in the shallow and principle 
aquifers has to do with its solubility also, and is of grave concern 
regarding our Orange County groundwater basin's water quality. 

The problem is basically that too much time has elapsed, enabling this 
contaminate to vertically percolate and horizontally migrate miles from 
the original point source on the base. We now have over 325,000 acre-feet 
of gndwater polluted with this carcinogen. And we're still squabbling over 
who is going to pick up the lion's share of the tab because there's a 
fly in the ointment, the added factor of a serious TDS contamination.

The Orange County Water District has developed a plan to build a desalter 
plant to cope with the TDSs. The Dept. of the Navy (DON) doesn't want to 
foot this added cost because none of their contractors have been able to 
satisfactorly prove that the Navy contributed to it. They say that it was 
a pre-existing condition. Who was the potentially responsible party (PRP)?
Perhaps we'll never know. 

But again we come back to the factor of time, i.e., rapid remediation. 
We dither over whether or not to pump n' treat exclusively, or to go 
with what the Clean Water Act statutory law states regarding utilizing the 
most affordable and best available technology (BAT). Everyone should realize 
that pump n' treat is one of the most costly methods of remediation. 
This technology in a stand alone mode without augmentation from innovative 
technology, e.g., in-situ air-sparging, might violate the original intent of 
the law. 

An outstanding case in point is the Savannah River remediation project. 
They successfully utilized air-sparging in conjunction with the "tried and 
true" pump n' treat process.

Pump n'treat is not the best available technology, but certainly is the 
best conventional technology (BCT), however we're not interested in 
inefficient methods because time is not on our side. It will take over 20 
years to partially clean up the TCE at El Toro utilizing BCT exclusively, 
and in the meantime a significant portion of our principle aquifer is 
undrinkable.

Perhaps there's someone out there that might have a better solution to 
our problem. Ce vous plait.

Don Zweifel
S/committee chair, OU-1 Groundwater,
MCAS, El Toro. Ca. RAB