By Leigh Martinez

STOCKTON (CBS13) — More than 1,000 people gathered at Stockton to find out of their drinking water is safe.

The concern is over the city’s planned use of the chemical disinfectant chloramine in the city’s water supply.

Inside the forum were arguments both for and against the use of the chemical.

Environmental activist Erin Brockovich says she came to Stockton, because citizens wanted answers about how safe the chemical is in the water supply. She repeated that the event wasn’t political, but started her speech praising Mayor Anthony Silva as a great leader and pledging to fight Gov. Jerry Brown’s Delta tunnels plan.

“We’ve been going to so many communities throughout the United States with chloramine issues that are having horrific lead problems and other concerns,” she said.

Stockton City Manager Kurt Wilson and city staff did not attend, as he said last week the event was political.

City Councilwoman Christina Fugazi says Stockton can’t be like Flint, Michigan, because the city doesn’t have lead pipes. But the primary speaker, a colleague of Brockovich, said there are no studies on chloramine’s effect on human health, and that breathing the chemical could be harmful to pregnant women. He advocated for Stockton to use carbon to clean the water.

But the city already approved the use of the chemical, leaving the question whether that can be overturned.

“It has to be something the public wanted to do, if they want to overturn it, they simply call their council members and we put it on the agenda,” Silva said.

Brockovich says Superman isn’t coming to save Stockton and the city needs to work together to create a healthy environment and that water shouldn’t be political.

“I think the defensive position is wrong. It makes me curious. Listen, this is all of our municipal water. We should be on the same team,” she said.