I have heard before of blackish stuff oozing from the ground in Texas after rain, but you say that the stuff you have seen is like seaweed. In that case it is probably algae, but when blackish stuff oozes from the ground in Texas, the first question that comes to mind is “Is this ‘Texas black gold?’ Could it be another Jed experience from Beverly Hillbillies?”

Most likely not. In most cases, the stuff oozing from the ground turns out to be decayed plant matter that has been previously buried by mud, clay, or dust. Eventually it rots under ground and when rains are heavy, it oozes from the soil.

My guess is that this substance is harmless and more likely to do good than harm, but to be sure I would collect a sample and take it to a lab for a soil test to find out what’s in it. Maybe also take some to your local agricultural department or UC Extension and ask them about it. They probably have heard of it before or if not, they might be interested to know about it.

At any rate it would be good to check into this because old dumps that have been covered over and built upon will often ooze in the manner you describe because of the weight of the houses built on top.

In the case of buried dumps that might be quite old and thus more or less forgotten, you would want to know just what the ooze contained so you could be sure it was non-toxic.

All the best,

Pat

Sincerely Misty mcneel