Boulder, Colorado

Project Management

Subsurface Investigation

USTs

ASTs

Client: Boulder County

Completion: 1999

Cost: $60,000

Pinyon assisted the Boulder County Facilities Management Division with underground storage tank (UST) and above-ground storage tank (AST) upgrades at various County-maintained facilities. These facilities included two criticality facilities (the Boulder Jail and Justice Center) and the Boulder County Court House.

Pinyon provided overall Project Management for the UST and AST upgrades, in addition to completing work necessary to obtain closure for other USTs.

Upgrades to the UST system at the Boulder County Jail involved upgrading the fuel distribution system and emergency generator tank to 1998 compliance standards. This involved adding spill and over-spillprotection to the existing USTs, terminating and capping a remote fill, and providing automated tank gauging. At the Justice Center, upgrades included the installation of spill and overspill protection and repairing the current the automated tank gauging system. Additionally, two 6,000-gallon emergency generator USTs were taken out of service and replaced with a smaller 4,000-gallon AST. This work was coordinated through a number of agencies, as the USTs were part of the back-up system for the entire City and County of Boulder Emergency Response, which is a criticality facility. The USTs were taken out of service simultaneously as the new AST is placed in service.

As part of the 1998 compliance standards, a UST which was used for the back-up system at the Boulder County Court House was abandoned in-place. Part of the UST was located beneath a sidewalk and landscape planter. The UST was also located adjacent to the Court House building, and to a below-grade utility corridor at the Courthouse. Removal of the UST could have potentially impacted the structural integrity of the Courthouse, as well as the utility corridors.

Prior to abandonment of the UST, the contents were removed and soil borings advanced in the vicinity of the UST to evaluate the presence or absence of contamination. Analytical results of soil samples collected from the borings did not indicate the presence of contamination. The UST was then filled with a concrete slurry. Closure was subsequently granted by the State of Colorado, Oil Inspection Section.