Parachlorobenzene sulfonic acid (PCBSA) is a feedstock chemical used in the production of DDT. A former DDT production facility is a superfund site; PCBSA is present at concentrations up to 40 mg/l, along with chlorobenzene, in a groundwater plume that is ~ 5000 feet long. This is because PCBSA is far more soluble and mobile than DDT itself, which adsorbs strongly to soil and is confined to the facility. At the 1st evaluation (~1996) PCBSA was not known to biodegrade. However, there was total oxygen depletion throughout the plume despite oxygen being present outside the plume, suggesting aerobic biodegradation may be occurring. A groundwater extraction and treatment system was installed to control plume migration with treatment eventually being a Hypox unit which removed a large portion of the PCBSA and the water was reinjected. A paper was published in 2008 showing that PCBSA is biodegraded by a Pseudomonas species (Blasco et. al. 2008). Injected water was well oxygenated and the injection wells capacity was reduced due to biofouling, suggesting biodegradation was occurring near the injection wells. Biofouling was addressed and alternative injection strategies and locations were evaluated to only promote biodegradation at a distance from the injection wells.
