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Driveways, sealcoating and Earth Day: Key things to consider

As we get ready to celebrate Earth Day on April 22, you might ask yourself, "What can I do to protect the environment?"

Any time you're doing things around the house is a good time to ask whether there's a safer alternative.

Consider your driveway. As the snow and ice melts and reveals the scars left by snowplows, snowblowers and spinning tires, your thoughts may well turn to sealcoat.

Each year, thousands of gallons of sealcoat are applied to driveways and other asphalt-paved areas in Minnesota. Until recently, the majority of that sealcoat was based on coal tar. However, the cancer hazards of chemicals in coal tar-based sealcoats are now known and other possible hazards are being studied.

Although the use of coal-tar-based sealcoat has been dropping, some Minnesotans continue to apply it to asphalt-paved areas.

But sealcoats don't stay where they're applied. As sealcoat wears, it turns into dust that can be blown onto play areas. Children contact this dust or track it onto carpets inside.

Sealcoat dust is also washed into our streams and ponds. There, it affects fish and the critters they feed on.

There are economic effects as well: removing coal tar-contaminated sediment from stormwater ponds costs property owners and taxpayers a lot.

That's why the Minnesota Pollution Control Agency (MPCA) is asking Minnesotans to choose safer alternatives to protect their paved areas, their children, and their communities. Here's how:

Understand what your pavement needs for maintenance. If replacement is needed, then consider concrete, permeable pavers, or one of the new, more durable asphalts.

If your asphalt pavement still has life, asphalt-based sealcoats have much lower levels of harmful chemicals than do coal tar-based sealants. They currently provide the best combination of pavement protection, cost and safety. New sealcoat products with no harmful chemicals are coming into the market and may prove the best choice in the future.

Talk to a couple of contractors about their experience with asphalt and other, safer sealcoat alternatives that perform well at reasonable cost. The MPCA recommends starting with a contractor who has pledged not to use coal tar-based sealcoat. To find one, either use this interactive map or get a name from this list.

Make sure best sealcoat application practices are used on your pavement: Prepare the surface thoroughly by cleaning it and sealing any cracks. Follow the manufacturer's mixing and application recommendations. Apply the sealant when the temperature's above 60 degrees and no rain is expected for at least three hours.

More on other resources available:

For do-it-yourselfers, these retailers don't sell coal-tar-based sealcoat: Ace Hardware, Home Depot, True Value, Menards, Hardware Hank, and Trustworthy.

If purchasing elsewhere, look at the label or data sheets and avoid products with the words "coal tar," "refined coal tar," "refined tar," "refined coal tar pitch," "coal tar pitch volatiles," "RT-12," "tar" or similar terms. Also avoid Chemical Abstracts Service (CAS) numbers 65996-93-2, 65996-89-6 and 8007-45-2.

The MPCA has detailed guidance at

Minnesota cities where coal tar application is banned include Buffalo, Cannon Falls, Centerville, Circle Pines, Eden Prairie, Edina, Elk River, Falcon Heights, Golden Valley, Hutchinson, Inver Grove Heights, Little Canada, Maplewood, Medina, Minneapolis, Newport, New Hope, Oakdale, Prior Lake, Rosemount, Roseville, Shoreview, Shorewood, Vadnais Heights, Waconia, West St. Paul, White Bear Lake, and Woodland.

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