During this reporting period the Responsible Party's contractor, ERM Inc., continued weekly oil extraction activities. During this reporting period recovery events occurred on 8/15, 8/21, 8/29, 9/06, and 9/12. The total liquids extracted thru 9/12 includes 17,088 gals of contaminated water and 3,378 gals of fuel oil. Weekly extraction events will continue.
On Wednesday Sept. 21, the FOSC met with Fogle's Project Coordinator and ERM Project Management at Fogle's offices. Purpose of the meeting was to review data generated to date and agree on immediate removal strategy based on this data. ERM provided an "Extent of Contamination Study Status Report." The findings as reported are as follows:
1. Document Records Review
a. only documented release was from the 10K AST
b. only registered UST was on adjacent property (Bill Groves & Son), a concrete 1000 gal UST, 558 Obrecht Road and was removed)
c. two previous owners known to have conducted fueling ops; USTs possible;
2. Geophysical Survey
a. one anomaly identified - possible historic UST;
3. Soil Gas Survey
a. several potential source areas identified: i.) former location of 10K AST, ii.)downgradient of geophysical survey;
b. elevated tph flux on hillside indicates possible migration pathway from source areas to seeps;
c. lateral extent of tph impact appears limited;
4. Soil Borings
a. extent of soil impact is very limited and localized to former AST area;
b. "landfarming" @ offsite fogle's property has likely reduced tph;
5. Groundwater/Oil Recovery Data
a. decline in free product thickness at seep area and MW-Ao1;
b. absence of free product at TMW-B2
General Conclusions:
a. volume of soil requiring remediation is 500-1500cy
b. pumping/recovery activities appear to have greatly reduced aerial extent of impact at seep area;
c. data gap - lateral extent of free product on the water table in vicinity of source area;
d. data gap - hydraulic response of groundwater in vicinity of source area;
ERM and Fogle's personnel will continue to inspect and replace sorbents in the creek as part of the required work under this AOC.
The two GAC water treatment units are onsite and will be utilized to ensure proper contaminated water treatment prior to on site discharge as per agreement. Samples will be retrieved prior to discharge to ensure compliance with the permit and agreement. All samples retrieved thus far have shown below NPDES permit requirements.
Weekly extraction events will continue but due to dry conditions the number of events may be curtailed.
No other activity was performed during this reporting period.
Proposed activities as a result of some of the data gaps include:
a. additional monitoring well install at MW-A01 area;
b. excavation of anomaly area at fogle's parking lot entrance;
c. excavation of 10K AST area, just above MW-A01;
d. formalize "landfarm" with engineering controls, runoff control to meet state requirements at offsite fogle's property;
e. EOCS report submittal in early November;
f. Abatement plan submittal in late November.
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