WORK PLANS - Laserfiche WebLink

Home Browse Search

(:VATC A S SOCIATES I N C . above method detection limits in the groundwater sample. Field activities are summarized in RESNA's Summary Report/Additional Soil and Groundwater Investigation, dated August 19, 1994. Based on the analytical results of soil samples collected during the advancement of soil borings, the horizontal extent of soil impacted by petroleum hydrocarbons is limited to the area beneath the fill end portion of the UST. The majority of the contamination exists within 36 feet of the fill end portion of the UST. The vertical extent of soil impacted by petroleum hydrocarbons is between 10 to 37 feet bgs. Based on the results of previous investigations, ATC conducted a study that considered three remedial alternatives to eliminate the potential for contaminated soil impacting the supply well. Remedial alternatives included excavation of remaining petroleum impacted soil, in-situ vapor extraction, and destroying the existing supply well and installing a replacement well in a location where it would not be threatened by the residual contaminated soil. The study concluded that replacement of the supply well was the most feasible method to address potential human health risks at the site. This study is summarized in ATC's Closure Report, dated May 8, 1998. In May 1999, Clark Well, Inc. installed a new supply well as a replacement to the original supply well. It is anticipated that the original supply well will be destroyed in January 2000, pending PHS/EHD approval. PROPOSED ABANDONMANT PROCEDURES AND METHODOLOGY Due to the location of the tank, BJJ Company, Inc. requested and received conditional approval for the in-place abandonment from the Montezuma Fire Protection District in January 1990. Conditions of the Fire District approval included: 1. The tank must be rinsed and filled with a substance acceptable to existing codes_ 2. All openings of the tank must be sealed to prevent possible vapors from entering adjacent buildings. 3. All requirements from other government agencies must be complied with as requested by those agencies. A copy of the Fire District's letter is presented in Attachment 1. The subject tank has remained empty since 1990 while closure in-place has been pending. In December 1999, ATC personnel visited the site to inspect access to the tank and measure the tank's contents, if any. Using a measuring sick,the tank was determined to be empty of product or sludge. Based on these findings, ATC subsequently contacted Fire Chief Ed Martel of the Fire District, WA94304VeponslUST dosure.doc 3