A well-known environmental activist is taking to Facebook to speak out against chemicals being added to Nipomo's water supply. Erin Brockovich shared her opinions about chloramine in a post on Friday.

A new pipeline is pumping water from Santa Maria to Nipomo. Officials are warning people in the community that they will be disinfecting the water supply, starting Tuesday.

Instead of using chlorine, they will be using chloramine to treat the water. Officials say it doesn't pose a threat to the general public, but chloramine can pose concern for people with kidney disease or those undergoing dialysis. Health officials also say chloramine can be toxic to fish and aquatic life.

Erin Brockovich disagrees with the safety claims of local health officials. She says Nipomo residents will be drinking ammonia and fluoride.

Brockovich claims chloramine leaves behind ammonia, which can cause bacteria to grow in the pipelines. 

"Now you will be exposed to toxins potentially 10,000 times more toxic than the byproducts formed by chlorine alone," Brockovich writes.

Erin Brockovich is best-known for a movie that shares her name. It chronicles her 1993 lawsuit against PG&E, about a contaminant in the town of Hinkley's drinking water.

The case was settled in 1996 for $333 million. That's the largest settlement ever paid in a direct-action lawsuit in United States history.