Green Landscaping and Gardening - Are coal ashes goods for anything?

I have a wood/coal boiler in my garage to heat my home during the winter, I burn about 6 ton of coal a winter. I take the ashes and dump them next to my garage and along my driveway in front of my garage. I'm trying to use them as fill to widen my driveway for an extra parking spot. I need about 2 foot of fill which will be covered with stone later on. Someone told me not to park a vehicle on the coal ashes because they produce some kind of acid and it would start rusting the under carriage of the vehicle. Has any one heard of this, or is it alright to park over coal ashes?

2nd. Are coal ashes good for anything?

Coal ashes contain many harmful things, including lead, mercury, and arsenic. Coal ashes should not be used in the landscape because of the potential to contaminate the water table. If you have a well, have it tested on a regular basis. Coal ashes should not be used as a fertilizer in lawns, as they are harmful to plants. Certainly avoid using them near plants that you eat. A soil test will reveal if landscape is contaminated. Contact local authorities for proper disposal of coal ash. Otherwise, store ashes in metal container and bag cold ashes and place with other garbage for disposal. Your local health department should be able to provide you with guidelines for disposal.

Thank you........

Someone told me not to park a vehicle on the coal ashes because they produce some kind of acid...

Are coal ashes good for anything?

Actually with rain water they produce the (also corrosive) opposite of acid, a very powerful base called "caustic soda", or, "lye".

You do not want to make face soap with lye derived from coal. ;) This is no good answer to your vegetable garden's ph level either. However there might be some use for the soda.

..?..

Hum, I get it. Coal ashes are bad.
This thread got me thinking... How about the ashes from my wood burning fireplace? Is that safe to be mixed into my compost?

Thanks for your time.
:thinker:

Wood ashes can be added to compost. Sprinke in thin layers so they don't clump.