Coal tar driveway sealants
Coal tar driveway sealants are poisonous (American Medical Associationand US Geological Survey). Winnetka baned them 2 years ago. Highland Park banned them in January, and Wilmette banned them Februay 28. I believe that most, if not all, retail stores in the area no longer sell Coal Tar sealants. However, it is used by contractors who sell their coating services without telling customers they are using coal tar, or where they are getting it.
Go Green Northbrook has asked the Village of Northbrook to ban them as a public health issue. Northbrook wants to wait for a statewide ban to be voted on this year before doing anything.
Meantime, if you need to maintain your driveway-parking lot there are several options . The AMA suggests several low cost alternatives for coating asphalt type driveways. But, these asphalt, acrylic or latex seal-coats still emit some PAH toxins and need frequent (e.g., annual) resealing depending on the use and local conditions .
Permeable paver driveways and parking lots offer a more environmentally friendly alternative. They absorb storm water with very little maintenance for 12-15 years at a moderate price. But, they need to be properly constructed: set on natural stone with NO limestone, sloped to drain water, and should have adjacent landscape that can absorb the water. Many contractors, however, coat the base of paving stone driveways with limestone. Limestone creates a solid base that doesn’t shift much over time and is less expensive in our area than neutral stone. But, this alkaline material chemically hardens the soil and stops the absorption of stormwater. And, it is death to most soil organisms and plants.
Another nice feature of pavers is that small changes in settling are easily fixed. Concrete paving always cracks and is expensive to replace. Asphalt also always cracks. As noted above, they can be recoated, but remain very toxic. When you walk on it you bring the toxins into your home and other buildings.
For further information you can contact me, Doug Gerleman