I would dig the soil out and send it to the landfill and then replace it with other soil.

Well, shoot . . . why didn't I think of that? Thanks, gjcore.

If it is not illegal to send that soil to your local landfill it should be. Many places today have laws that prohibit sending any yard waste to any sanitary landfill and require anything that might be hazardous waste to be sent to an approved hazardous waste disposal site which cost you a fairly large sum of money.
What you may need to do with that area, instead of replacing the soil is add, in to that soil, organic matter, simply putting some on top apparently is not going to help as quickly as you wish.

18" area? I'd find a 24" ornamental rock. Seriously though, I'd try digging in some (a lot) not quite mature compost in that spot and see if those microbes could take care of it.

There is a lot of info on the web about using compost for remediation. If a person had time they could wade through it all in the hopes of finding something specific but I'm more of a 'throw the instruction manual away' kinda guy and just try it.

If you do, take pictures, document what you did and when. This type of question comes up once in a while and it would be nice to have someone who's BTDT.

Lloyd

While I tend to agree with the 'fix it first rather than replace it' approach, landfilling it also crossed my mind. A few things to consider if you're going to do that:

If yard waste is in fact prohibited in your area, that often applies only to compostable green waste, not soil. In fact, the landfill puts 6" of dirt on top of the daily truckloads of trash, by law.

Soil contaminated with diluted latex paint water is NOT hazardous waste. It's not even household hazardous waste (a category which allows you to throw things in the landfill that businesses could not - not that I'm advocating that - always reduce reuse recycle). In fact, to dispose of waste latex paint it's usually recommended to let it dry out and throw it in the trash.

YMMV because I don't know what state you're in, but this is how it typically is.

I do hate the landfill and hope you will be able to fix your patch.

'morning treelover, I may have had the closest experience similar to yours. About fifteen years ago there was a transformer that got hit by lightning on the property. The electric company was not very careful and spilled some of the contents. A spot about three feet in diameter died, had a horrible odor when the sun beet on it, and generally water was repelled by it.
Nothing grew there after even two years went by. What to do, the company denied having anything to do with it. One day by chance I had a cold cup of coffee and threw it on the spot. A few days later it just looked different. So I started adding the left over cold coffee to the spot. Then the coffee grounds. In a few months the spot was fine and grass grew there again.
If I was to have that problem again I would consider an occasional pee on it.
Try it all the ingrediants are free. Best regards to all.

pagardner, I certainly hope that was a PCB-free transformer...

toxcrusadr, whatever it was is still there. The Op here is talking latex paint. My suggestion is still valid.

I won't take it to the landfill. Instead, I'll replace the soil there with some from under a compost pile that I just harvested. Will mix a little compost & ucg in with it. Won't pee on it, though, since it's right out in the front yard.

By the time the next batch of compost is done, the bad soil that I'll put at the bottom hopefully will be okay.

Thanks all!

The fluid in the transformer was probably mineral oil.

When grass won't grow, get a soil test. I like The Texas Plant and Soil Lab, in Edenburg. Get the test that does salts and micronutrients as well as the regular nutrients. It could be as simple as correcting the salt balance. Or it could be the paint had boron in it. Too much boron will prevent plants from growing. You can't know until you get the test back. No matter where you have it tested, tell them what's going on.

Latex paint isn't hazardous waste. True. Including for grass. Especially if it's just from cleaning tools. I've dumped latex paint waste on my back lawn. No problems at all. Personally, that tells me that more was dumped there than the latex paint and water. And THAT could be hazardous waste if it kills grass better and longer than other hazardous materials. Just something to keep in mind.

My family has been in painting contractors for almost 30 years there are not very many exterior jobs that don't require even a little oil base primer which would be mineral spirits cleanup which would kill grass although we would never clean up equipment or dump material in a yard a spill could happen

I think everybodys suggestions are valid except sending any form of yard waste to the landfill they are not majic black holes throw some dirt on top and seed it in

Or take the grass you pull from your flower beds and dig it in see what happens