City council voted on Thursday to ban coal tar sealants in the San Antonio. The city is now the largest in the country to ban the product.

The sealants are sprayed on parking lots and driveways to protect them from wear and tear and the effects of erosion. Environmentalists from the area say that the sealants contain harmful chemicals.

"It's a pollutant to our waterways and, here in San Antonio, we get a significant portion of our water supply from the Edwards Aquifer which doesn't filter these contaminants," said Annalisa Peace, executive director of the Greater Edwards Aquifer Alliance.

However, opponents of the ban say that many environmental organizations don't classify the sealants as hazardous.

"There's no data indicating that there has been a problem. There's no problem now and there's no anticipation that there will be a problem," said Anne LeHuray, executive director of the Pavement Coating Technology Council.

Several local business owners are also concerned that banning coal tar sealants would mean that they would have to pay more for an alternative sealant and that they would have to close their parking lots more often because the alternatives don't last as long.

After reviewing more than 80 documents and studies, city council concluded that the risks of the sealant were too much to ignore. The ban will go into effect on January 1, 2017.