United States Environmental Protection Agency
Region X
POLLUTION REPORT

Subject: 

Alley Fuels was a bulk fuel distributor and card-lock retailer on the Banks/Lowman Highway, approximately 5 miles west of Garden Valley, Idaho.  The facility consisted of 5 above ground storage tanks (from approx. 5,000 to approx. 10,000 gallons) containing gasoline and diesel fuel.  On April 15, 2003, Brico Oil, the supplier to Alley Fuels, reported to the Idaho Department of Environmental Quality (DEQ) that 5,000 gallons of unleaded gasoline was unaccounted for and suspected to have leaked into the ground from one tank at the Alley Fuels facility.  Upon inspection, a hole was found in the bottom of the tank.  The leaking tank is 470 feet from the Middle Fork of the Payette River, with an approximately 50 foot elevation drop to the River.  The owner/operator of Alley Fuels indicated to DEQ and EPA that he did not have the resources to conduct necessary site investigation to determine the extent and migration of spilled gasoline in subsurface soils and groundwater.  The facility has since ceased operation, the leaking tank removed, and other tanks emptied.

On 7/14/03, EPA and EPA's START contractor mobilized to the site to conduct site investigation to determine whether spilled gasoline presents an significant threat of discharge to waters of the U.S..  A survey of the river bank and seeps along the area did not indicate a present discharge to the Payette River.  START contractor installed six monitoring wells to determine subsurface characteristics, including groundwater depth and flow direction and soils type, and to try to locate the spilled fuel.  Groundwater was observed at approximately 25 feet below ground surface.  Sample results showed highly contaminated soils at approximately 1 to 3 feet above the water table, indicated that groundwater had dropped significantly from the time of the spill, creating a "smear zone."  Free phase petroleum was not observed in any of the wells, indicating that spilled petroleum was still largely hung up in the smear zone and/or the slug of it had already migrated through the area of the monitoring wells.  
        

On April 8, 2004, EPA and START contractor personnel re-mobilized to the Site to evaluate current conditions relative to discharge or threat of discharge to the Payette River.  Previously installed wells were monitored to determine groundwater elevation and flow direction.  From 4/8/04 through 4/12/04, START and drilling subcontractor drilled 4 additional monitoring wells in locations down gradient of previous well installations.  The drilling subcontractor initially attempted to drill borings with a hollow-stem auger.  They, however, encountered boulders apparently used to armour the edge of the embankment.  The drilling sub was directed to mobilize a compressor and additional equipment from Spokane to the site to use air rotary drilling techniques.

Two wells were located on the top edge of the embankment leading to the Payette River, and two more wells were located over the embankment along a dirt road that approaches the River.  No free product or sheen were observed in any of the new wells.  A petroleum odor was noted in one of the wells above the seep area on the embankment to the River.  Also, a petroleum odor was noted at the seep, but no sheen observed.

Groundwater was monitored in all existing and new wells.  A less than 1 inch layer of product was observed in earlier installed MW01, which is the well closest to the former leaking tank.  Groundwater samples were collected in all wells except MW01.  All personnel demobilized from site on April 12, 2004.

Based on field observations during the most recent site investigation activities, the Site continues to pose an indeterminate threat of discharge of petroleum to waters of the U.S..  Petroleum odor reported at the seep area is troubling, however there was no noted product or sheen at the seep or in wells between the seep and the former leaking tank (except for MW01 closest to the former tank installation).  Based on this information, a removal action to mitigate a discharge or threat of discharge to waters of the U.S. is not warranted at this time.

START contractor will obtain analytical results of groundwater samples from new and existing wells, and soil samples from new well installations.  Based on this data, START will prepare a draft report for the OSC's review with conclusions and recommendations regarding threat to waters of the U.S. from petroleum contamination at the Site.  

The OSC will periodically inspect the seep for visible sheen or discharge when he is in the area.  It is also likely that an additional round of groundwater monitoring will be warranted.  No additional well installation or cleanup action is planned at this time.