Ecologically Best Cleaning Agent - for runoff

Asked July 21, 2020, 12:14 PM EDT

I'm planning to clean my garage floor of years of accumulated dirt, grime, and entrenched oil residue from vehicle leaks (everything that can be is scraped off first, and but in landfill trash), and want to choose a cleaning agent that is environmentally as safe/neutral as possible. The runoff from rinsing will be going into the city storm sewer.

One choice is muriatic acid, initially diluted 3:1 and further diluted when rinsed off. My sense is this will not significantly increase the ph of the sewer water and may well be harmless.
Another choice is TSP which is a very caustic cleaner. I don't know for sure if this will harm the environment, but I know there is a general concern about more phosphates in the environment.
Finally, you may be aware of yet additional cleaning agents to help get this garage floor clean.

Any information will be greatly appreciated, as I'm trying to be as responsible as I can about this project.

Washtenaw County Michigan

1 Response


Thank you for considering the impact of your project on water in your area. That is a very important consideration to make given the potential impacts it could have. Muriatic acid can have profound impacts to you (ex: chemical burns) as well as to foliage in your yard (from runoff) if not managed extremely carefully. Similarly, TSP is also a powerful cleaning agent and can negatively impact your health and landscaping if not used properly. In addition, excessive amounts of phosphorus can have profound impacts to surface water.

I do not have any specific cleaner recommendations, however I would encourage you to check out the EPA Safer Choice product website ( Safer Choice products are reviewed by the EPA. All chemical ingredients, regardless of their percentage in the product are evaluated. Every ingredient must meet strict safety criteria for both human health and the environment, including carcinogenicity, reproductive/developmental toxicity, toxicity to aquatic life, and persistence in the environment. Their website has a listing of products that meet their standards ( If you search by product type, I imagine you will find something that will work for your needs. Safe Choice products are labeled accordingly and can be found at major retailers.

When reading labels its important that they have the EPA Safer Choice logo. Products labeled "natural", "green", "environmentally friendly" may not mean anything at all. But having the EPA Safer Choice logo means the product has met specific guidelines.

Good luck on your project!