Remediation System Activated Carbon

The City of Tucson Environmental Services (ES) would like to establish an annual requirements contract with multiple firms on an as-needed, if-needed basis, to provide activated carbon for ground water and soil vapor remediation systems. The carbon would be used to remove Volatile Organic Compounds (VOCs), including chlorinated solvents; Freon compounds; Benzene, Toluene, Ethylbenzene, and Xylene (BTEX); Methyl Tertiary-Butyl Ether (MTBE); and Per- and Polyfluoroalkyl Substances (PFAS) from ground water pump and treat systems, as well as soil vapor extraction systems at active remediation sites within the City limits. Spent carbon from our facilities is not normally classified as a Resource Conservation and Recovery Act (RCRA) or State hazardous material.

ES is currently responsible for maintenance of carbon at several low-pressure ground water pump and treat systems: one with two (2) 20,000 lb. carbon vessels; and one with two (2) 5,000-pound (lb.) carbon vessels. The provider is not responsible for back flushing, chlorinating or coliform testing at any of these sites. ES maintains one vapor phase remediation system, two (2) 55-gallon drum vessels which are operated at pressures less than 20 inches of mercury. ES operates one (1) mobile 1,000-lb Granular Activated Carbon (GAC) vessel for treating impacted ground water during sampling events at one of our facilities. In general, the carbon vessels are filled to the rated capacity (i.e., a 4,500-pound carbon vessel contains approximately 4,500 pounds of carbon).

The 20,000 lb. carbon vessels are typically changed out three times per year. The unit in the Soil Vapor Extraction (SVE) system is exchanged when contaminant breakthrough is reached.