A few months ago, my car had a major oil leak ( Rear Main Seal ), and when I started it up, oil basically POURED right out in A STREAM, and my car went through one quart of oil in like 5 minutes. There was a HUGE puddle of oil all over the driveway. I used kitty litter to try to soak it all up. and then tried to wash it away with some "Dawn Dish Soap".
Anyway, now everytime it rains, the driveway gets puddles of that "rainbow colored" oily water. When I try to wash it with the "Dawn Dish Soap", the white foamy bubbles from the Dish Soap turn all Black. So the bubbles all turn this foamy Black color, and the water underneath is all rainbow colored.
So the other day, what I noticed after the snow melted on the grassy area next to the driveway, was that there was an area about 3-4 feet long, and about 1 foot wide, where the grass has turned all Black, and the soil is now a GRAY color. The reason for this, is because the asphalt driveway is very old, and not perfectly flat, and so the water and melting snow runs down onto the grass and soil.
So does this mean that the soil is now contaminated with oil? Do I have to dig out all the grey-colored soil, and reseed the whole area? If so, how far down do I need to dig?
Instead of digging all the soil out, can I fix the soil, by just topdressing the gray soil with some compost or organic topsoil, and then reseed?
Because its not like the motor oil was dumped or spilled directly on the grass, but the oily residue in the driveway mixed in with rainwater and melting snow, and turned the grass Black, and the soil a greasy/oily grey color.
Any suggestions would greatly be appreciated!!!
P.S. Is there anyway to DRY OUT the oily residue in the driveway, so that when it rains, the puddles won't have that oily, rainbow color? Will scattering "rock salt" down on the area where the oil spill was, help to dry it out? Because doesn't rock salt dry stuff out?