Mr. Hofenbredl has completed the three major removal actions:
Excavation of the heavily contaminated soil near the pumphouse: 268 cubic yards were excavate of which 195 cubic yards were highly contaminated. The contaminated soil was spread in treatment cells on the property and in accordance with ODEQ requirements. The soil has been tilled twice a day. Clean soil was brought in to refill the excavation. Soil samples were taken from the contaminated soil on September 17 and were sent to a laboratory to determine the concentration of contamination. Lab results of sampled soil show soil to be clean and can now be spread according to the permit.
Excavation of two interception trenches. This was completed on August 29: Each trench has a drain tile, a plastic barrier downgrade, and a sump for collecting product. Four ground water monitoring wells were installed on September 17 and 18. Pumps need to be installed.
Sparging of water initially collected in Baker Tank: Samples were drawn and concentrations of contamination in water met ODEQ requirements for disposal of water on land. ODEQ issued a 1500B NPDS discharge permit and the water was discharged to the land. The Baker Tank will be replaced with another tank that will allow for better sparging of water to be collected from the sumps.
Other activities:
The original wells installed by EPA were removed since they did not meet Oregon DEQ requirements for long-term installation. New monitoring wells were installed on 9/17 - 18/03 that meet ODEQ requirements.
Tim O’Gara spoke with Dr. Griffith, the State Historical Preservation Officer, about planned activities at the site who advised Mr. O’Gara on antiquities to watch for and steps to take if any are found.
The US Coast Guard case officer, Miguel Bella, visited the site with Andy Smith on Monday, August 11. He met with Mr. and Mrs. Hofenbredl.
An Administrative Order for Removal was signed by EPA on 8/11/03 and by Mr. Hofenbredl on 8/25/03.
EPA received on September 22, a letter from Enumclaw Insurance Group informing us that the costs for testing and cleanup of gasoline contamination on Hofenbredl’s premises and off premises are not covered.
Water will be pumped from the sumps of the interception trenches into a holding tank once the water table rises with the onset of the wetter season. A float valve will be place in the sump which will activate the pump automatically as the water level rises.
Samples will be drawn from the monitoring wells. If samples are less than 5 micrograms benzene per liter water for four consecutive quarters, the site will be closed.
None.
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