You know what they are – the tried and true sources of stormwater pollution like dog poop, lawns with fertilizer, pesticide or herbicide applications, poorly maintained septic and sewer systems, or improperly maintained construction sites to name a few. Once in a while something new gets added to the list, here in Connecticut in recent years it has been Polycyclic Aromatic Hydrocarbons (PAHs) from coal tar-based pavement sealants.
These sealants are used to coat pavement and give it a uniform dark appearance. They contain high concentrations of a range of PAHs – including certain varieties that are likely to cause cancer in humans. Exposure to coal tar pavement sealants is not just a concern for people applying it to roads and driveways but also to anyone who lives near pavement treated with it (like driveways or parking lots) because the coating degrades over time and then gets tracked inside our homes and businesses. It’s also harmful to aquatic organisms when it runs off into waterbodies with stormwater.
On a fateful day in 2016, a coal tar-based sealant was applied to local roads in Pomfret, CT, and nearby residents raised health and safety concerns to town officials. Town officials then asked the state for guidance on whether this product was safe to use. As a result, Connecticut officials from DPH and DEEP clarified that these products are not safe for humans or the environment. And because comparable alternative products with much lower toxicity are available– the state legislature quickly passed a ban on state and local roads in 2017. Other states and municipalities have passed similar bans and even Home Depot has stopped carrying coal tar-based sealants.
Private property owners are not covered by this ban so it is important that everyone understands the hazards associated with using coal tar-based sealants.
Find more coal tar-based sealant information below if your interest is piqued!
CT Department of Public Health’s coal tar-based sealant page
UNH coal tar-based sealant brochure
Environmental Effects of Coal Tar-Based Pavement Rejuvenators