Planting food in a parking lot garden

I'm working with a community that has a neglected parking lot green space that they want to transform into an edible landscape. There is no artificial water source. Rain and run off from the parking lot is it. I'd like to capture the parking lot run off, but the community has concerns about the water being contaminated by the asphalt. Has anyone dealt with a similar situation? Thoughts? Thank you.

Ruth O'Carney wrote:I'm working with a community that has a neglected parking lot green space that they want to transform into an edible landscape. There is no artificial water source. Rain and run off from the parking lot is it. I'd like to capture the parking lot run off, but the community has concerns about the water being contaminated by the asphalt. Has anyone dealt with a similar situation? Thoughts? Thank you.

It would squick me out unless it's been car-free for a long time, and is visibly clear of contamination..

Any chance of getting water from roofs, if this lot served buildings, or there are some nearby?

Parking lot runoff is going to have some contamination, no matter how long it has not been used as a parking lot.
Asphalt leaches for decades and the spots where leaky cars parked will only add to the contamination problem.
You can partially purify the water so it can be used on gardens, you would need a minimum 6 ft. sand filter and then a remediation field that has rushes and moss for the water to filter through and the soil for these needs to be occupied by oyster mushroom mycelium.
This water would not be potable but more along a good gray water quality wise which makes it suitable for use in gardens that grow foods.

Redhawk

Perhaps edible for wildlife is a more reasonable goal than edible for humans.

Plus the wildlife will notbjust eat there, the birds will fly off and drop seeds, spreading edibles to areas where it would be OK for people to eat what is produced.