Whitten Oil 1

Ecology received the draft Remedial Investigation Work Plan at the end of January. The plan proposes to investigate petroleum-related contamination by:

• Inspecting and repairing or abandoning, as needed, five existing groundwater monitoring wells
• Installing four new groundwater monitoring wells and collecting soil samples from their boreholes
• Collecting soil vapor samples from two locations inside the convenience store and one behind it

After Ecology approves the work plan, the investigation will begin.

The site has been used to distribute petroleum products since the 1950s. Whitten Oil began operating there in 1973. In 1989, workers removed six underground storage tanks and surrounding contaminated soil. One underground storage tank was closed in place under the former gas station building. Further investigation found more soil contamination and groundwater contamination. 

Since 2017, groundwater has been sampled twice a year. In 2018, levels of petroleum and VOCs in groundwater began to increase. In 2023, Ecology decided a new investigation and further cleanup are necessary because the extent of contamination is unknown and may be threatening nearby residences. 

Businesses and homes within the City of Colville get drinking water from the city. This water is regularly tested under the Washington Department of Health’s regulations and is safe for drinking.

However, if contamination spreads under nearby buildings, it can cause harmful vapors to build up inside them. This is called vapor intrusion. Ecology is requiring the investigation and cleanup to prevent vapor intrusion and the contamination spreading further.