Specialized Services Company (SSC) has already vacuum excavated more than 100 potholes in preparation for the City of Mesa’s new soil-cleaning and well monitoring systems being installed to counteract the effects of five 1990s fuel leaks.
A lingering contamination site beneath Mesa’s Sixth Street Service Center contains a variety of contaminants that are routinely found in petroleum products and include benzene, toluene, ethyl-benzene and xlylene as well as MTBE (methyl tertiary-butyl ether). According to a city report, all of the chemicals, except for the MTBE, are confined to the groundwater beneath the service center.
Mesa is the third largest city in Arizona and the nation’s 40th largest city. It encompasses 131.2 sq. mi. (339 sq km) and is home to more than 400,000 residents, whose drinking water has so far not been affected by the chemicals.
According to city officials the cleanup wasn’t started earlier because the Arizona Department of Environmental Quality wouldn’t approve the plan until the full extent of the contamination was evaluated.
Although the extent of MTBE contamination outside the service center area is still yet to be determined, new state mandates are pushing for a faster clean-up, according to Christine Zielonka, Mesa’s development services director. In response, the City of Mesa contracted Specialized Services Company to prepare the site for a $1 million clean-up system that will pull the toxic chemicals out of the ground. Approximately 12 to 14 interconnecting monitoring wells of 200 ft. deep (60 m) and a new building, which will house pumping equipment necessary for testing, is planned.
Beneath the Sixth Street Service Center exists a web of documented and undocumented private utilities that service the area. In order to avoid any conflict with the existing underground infrastructure, SSC used its state-of-the art vacuum excavating technology to expose and map all utility lines in the path of the new system and pump building. This technique eliminated the possibility of further environmental damage to the area. Vacuum technology uses air to break up soil around the utility and a high-powered vacuum to remove the excavated material. According to Richmond Ellis, SSC’s vacuum division supervisor, the potholing efforts were so successful, the city is considering SSC to assist with all the trenching necessary for the project, instead of open-cut trenching, “which is notoriously more dangerous.”
Once the site is rendered safe for construction, the city plans to hire Conestoga-Rovers & Associates, known for its work at the Love Canal to complete the project. In the meantime SSC plans to begin clearing 6-ft. (1.8 m) deep holes for the monitoring wells.
For more information, call 602/997-6164 or 480/644-3800 or visit www.sscboring.com.