DSHW-1990-001381 - 0901a0688014066f

. T UFRCLII_ES Hercules Aerospace Company
^^^^^^^^^^^_ Missiles, Ordnance and Space Group
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..^.Bacchus Works
i Jlagna, Utah 84044-0098
"[phone]
May 11, 1990
CERTIFIED MAIL - RETURN RECEIPT REQUESTED OSHW TN
. ^ 1990-20801
Dennis Dovms
Director
Bureau of Solid and Hazardous Waste
Division of Environmental Health
P.O. Box 16690
288 North 1460 West
Salt Lake City, Utah 84116-0690
Re: Reply to the Bureau of Solid and Hazardous Waste Letter Dated
March 30, 1990
Dear Mr. Downs:
In response to the questions raised by your staff concerning the
"Contaminant Transport Modeling of a Chlorinated Solvent Plume East NIROP
Area", "East NIROP Ground Water Modeling" and "Work Plan for Drilling of
Additional Monitoring Wells in the East NIROP Vicinity" the following is
Hercules' reply:
A. UBSHW Comments:
1. "Hercules should consider collecting VOA samples from Piezometer P.3
prior to drilling the on-site deep well. If P.3 can be purged and a
sample collected, valuable infonnation could be generated conceiming
VOA contamination in the deeper portion of the aquifer."
2. "Extreme care will need to be taken in drilling GW-73 to ensure that
contamination is not spread to possible clean zones within the
aquifer."
Reply: Hercules has contracted EarthFax Engineering to begin
construction of deep well GW-70 (tentatively called GW-73 in the NIROP
Work Plan). Hercules is acutely aware of the extreme care and precise
drilling/casing practices which need to be adhered to while drilling
through the upper aquifer and into the lower aquifer. Hercules has
expressed this very concern to the Bureau on many occasions and
understandably has been reluctant to do deep drilling for this very
reason.
We have communicated our concerns to EarthFax Engineering on the matter
and they have assured us that every precaution will be taken.
BW-1000/689 (Rev 2/88)