Snappy Mart

A Triad planning exercise for the Snappy Mart #11, West Plains Missouri.

Site Background

A systematic planning meeting was held in September 2006 about Snappy Mart #11, West Plains Missouri. Attendees included MDNR, the state contractor administering the PSTIF, a Snappy Mart site consultant, and EPA and Argonne representatives.

The consultants for the site owners defined the problem at the site by using the conceptual site model (CSM) available. An exit strategy was developed assuming the following:

• The release from the tank pit to the surface water feature is caused by the drainage of product from pipeline/trenches system to the tank pit.
  
  
• The sampling proposed confirms that releases to the pipeline/trench and residual contamination in the pipeline trench are not a groundwater contamination source.

During the brief systematic planning session, MDNR elaborated on several goals to be achieved at the site:

• Expeditious removal of free product from the tank pit to the extent practical.
  
  
• CSM refinement including site characterization: vadose zone soil in the pipeline trenches to 20 feet.
  
  
• Underground utility investigation/characterization.
  
  
• Absent evidence of contamination at 20 feet from borings that straddle the pipeline trenches, MDNR would not require groundwater monitoring.

The critical components for developing future decision logic were the need for:

• the immediate removal of free product from the tank pit to preclude releases to a nearby surface water feature,
  
  
• the removal of a soil stockpile at the site,
  
  
• investigation of pipeline chases, and
  
  
• installation of two geotechnical borings to bedrock.

Participants used the Snappy Mart Web site, a collaborative on-line workspace, as a resource for communicating, critiquing, and strengthening planning documents. Participants also used multiple teleconferences led by EPA OSRTI and PSTIF to discuss the results of newly generated data.

Site Progress

A work plan was approved January 17, 2007, and field activities were conducted during April of 2007. The results of the field investigation activities were discussed in a teleconference meeting on June 15, 2007. A follow-on work plan was submitted and approved in August 2007. Additional field activities were conducted in September 2007. Field activities have involved the advancement of borings along pipeline chases, the installation and sampling of monitoring wells, the sampling/analysis of inactive water supply wells, and a receptor survey to identify surface and subsurface cultural and ecological features located near the facility. In addition, field activities have included the periodic pumping and removal of liquid that accumulated in the tank pit containing active USTs. To some extent, the Snappy Mart team relied upon RTMS, a PID, for the identification of soil intervals from soil borings for off-site laboratory analyses.