Blaine Mini Mart

The Blaine Mini Mart Site is an active Shell-branded retail service station. The site is located at 2530 Peace Portal Drive in Blaine approximately 1,500 feet northeast of Drayton Harbor and 1,000 feet North of Dakota Creek.  Site facilities currently include a station building, four dispenser islands, and three steel single wall USTs, including two 12,000-gallon unleaded gasoline USTs and one 12,000-gallon diesel UST. The USTs were installed in 1980.
                                                      
The property was originally developed for residential purposes, which included one house and two additional unknown buildings. In 1955, these structures were removed and the current convenience store and dual bay storage space were constructed. In 1980, four USTs located in front of the Mini Mart, where the current fuel dispenser canopy is located were removed. No documentation of soil conditions was reported. The current owners, Yon and Inson Kim, purchased the property from Bell and Drake Enterprises in November 1997.  
 
In October 1997, an initial soil and groundwater investigation was completed prior to a property transaction. Two groundwater monitoring wells (MW-1 and MW-2) were installed. Previously installed tank observation wells OW-1 through OW-3 were sampled. A slight hydrocarbon sheen was observed during sample collection at OW-1.
 
In November 2005, seven soil borings (SB-1 through SB-7) were drilled to define the nature and extent of petroleum hydrocarbon contamination in soil and groundwater. Oily globules floating in the water column and a strong petroleum odor was observed in monitoring well MW-2.
 
In March 2010, with funds made available by the American Recovery and Reinvestment Act (ARRA) 21 soil borings (SB-08 through SB-28) were drilled and three monitoring wells (MW-3 through MW-5) were installed to define the horizontal and vertical extent of contaminated soil exceeding the MTCA Method A cleanup levels (CULs). Two separate petroleum-contaminated areas on the site were identified.
 
Between April and May 2011, remedial actions were completed to remove accessible petroleum-contaminated soil south of the former garage area and in the vicinity of the former fuel dispenser islands and USTs located along the western side of the site. Approximately 5,057 tons of petroleum-contaminated soil was removed from the two excavation areas.  Although a significant portion of the petroleum source material in each of the excavation areas was removed, some localized contaminated soil remained. As a result, approximately 8,000 pounds of a controlled oxygen-releasing redox compound (Adventus EHC-O®) was applied to the sidewalls and base of the excavation, which will promote further attenuation of the petroleum source through enhanced bioremediation. Following the excavation activities three groundwater monitoring wells (MW-6 to MW-8) were installed.
 
The following analytes have been detected above the MTCA Method A CULs in soil and/or groundwater:

• TPH as gasoline
• TPH as diesel
• TPH as heavy oil
• Benzene
• Toluene
• Ethylbenzene
• Xylenes
• Methyl tertiary-butyl ether
• Naphthalenes 

Based on the results of the 2011 remedial investigation, additional groundwater monitoring is needed to determine the effectiveness of the remedial action. Semiannual groundwater monitoring is currently being completed at the site.