Volatile organic compounds are a broad category of carbon-based chemicals that readily evaporate at room temperature. In the context of drinking water, the VOCs of concern are primarily industrial solvents, degreasers, fumigants, and petroleum-derived compounds that have found their way into groundwater through industrial activity, improper disposal, underground storage tank leaks, and Superfund site contamination.

Some of the most common and regulated VOCs in drinking water include trichloroethylene (TCE), tetrachloroethylene (PCE, also called perchloroethylene), benzene, toluene, ethylbenzene, and xylene — the latter four often grouped together as BTEX compounds due to their common origin in petroleum products and gasoline.

The Metro East has a significant industrial legacy that makes VOC contamination a relevant concern for residents, particularly those near industrial corridors. The Chemetco Inc. Superfund site in Hartford, Madison County — a former copper smelting operation — is a documented source of heavy metals and industrial VOC contamination in groundwater. Multiple industrial sites along the Madison and St. Clair County corridor have contributed to subsurface contamination over decades of manufacturing activity.

Dry cleaning operations, auto repair shops, and fuel storage facilities are additional local sources. PCE is the primary solvent used in dry cleaning and is one of the most commonly detected VOCs in urban groundwater nationwide. Even in areas without obvious industrial activity, VOC contamination can migrate through groundwater from distant sources over time.

VOC health effects vary significantly by compound, concentration, and duration of exposure. As a general category, VOCs are associated with liver and kidney damage, central nervous system effects, and increased cancer risk with long-term exposure. Several specific VOCs carry serious regulatory designations.

TCE and PCE are both classified as probable human carcinogens. Benzene is a known human carcinogen with no established safe level of exposure. Vinyl chloride, which can form as a breakdown product of TCE and PCE in the environment, is also a known carcinogen. The EPA has established MCLs for most regulated VOCs, though standards vary by compound and are subject to revision as research develops.

VOC testing requires EPA Method 524.2, which screens for a comprehensive panel of compounds simultaneously. Our Clarity and Certainty packages include a full VOC panel covering over 60 compounds including all major industrial solvents, BTEX compounds, and petroleum-derived chemicals.

Activated carbon filtration is the primary treatment approach for most VOCs, with granular activated carbon (GAC) and carbon block filters both effective depending on the specific compounds and concentrations present. Systems certified under NSF/ANSI 53 for VOC reduction are the appropriate standard to look for. Reverse osmosis is also effective at reducing VOC concentrations and provides an additional layer of protection.