At low-level concentrations, the cancer-causing chemical can turn clear water yellow, and when it’s really bad, a water source contaminated with ‘chrome-6’ can flow purple.
But even when tap water is perfectly clear, Brockovich admitted she’s still "funny about water," and rarely, if ever, drinks straight from a tap.
"I think we’re pretty convinced that these chemicals are immune toxicants that we should be concerned about," Linda Birnbaum, a microbiologist who directs the National Institute of Environmental Health Sciences at the National Institutes of Health, said last month.
Eight big chemical companies in the US (including DuPont and 3M) voluntarily phased out the chemicals in their products and replaced them with new ones by 2015.
How to ensure your water is safe to drink The first thing you can do if you’re worried about the quality of your tap water is read your local water report.
She has even agreed to endorse a filtering product for the first time ever: the AquaTru home water filter.
Plus, bottled water is often just treated tap water, and the products are generally less regulated than what comes out of the tap.
But the Food and Drug Administration (FDA) lets companies use the label "purified water" on water that’s been treated in several different ways, so it’s not always clear how it’s been filtered.
"I let consumers know, use your own common sense … if it looks funny or smells funny, don’t drink it."
Water-quality data for cities and towns around the country is required to be reported every year, and it’s available on the EPA’s website.

A federal appeals court reinstated an environmental group’s lawsuit Thursday that accuses Pacific Gas and Electric Co. of contaminating San Francisco and Humboldt bays with potentially dangerous chemicals in a wood preservative used on utility poles.
The suit said oil and wood waste from poles stored at the yards washed into the bays, damaging the environment and endangering wildlife and human health.
The environmental group wants a court to order PG&E to halt or clean up the discharges.
The Environmental Protection Agency decided many years ago not to require permits under that law for storm-water discharges.
But because the agency could have ordered permits, Seeborg said, the discharges were subject to the Clean Water Act and could not be challenged under the Resource Conservation law.
The Ninth U.S.
“The Clean Water Act does not require PG&E to get a permit for these discharges,” Judge Marsha Berzon said in the 3-0 ruling.
The EPA filed arguments supporting reinstatement of the suit under President Barack Obama, and argued on the side of the environmental group at the court’s hearing in February after President Trump took office.
Berzon said the group’s members had adequately asserted “their reduced ability to enjoy eating local seafood in Bay Area restaurants, observing birds and other wildlife from the air or from the wetlands around Oakland Airport, or sailing and swimming safely in San Francisco Bay, among other harms.” Jason Flanders, a lawyer for the Ecological Rights Foundation, said the ruling closed “what could have been a major loophole in pollution law.” Asked for comment, PG&E spokesman Matt Nauman said, “The health and safety of our customers and the public is our top priority.
We are aware of the court’s decision.

In support of Gov.
Jerry Brown’s call for all customers to make water conservation a new way of life, even as he declared the official end to the current drought, Pacific Gas and Electric Company (PG&E) is announcing new water management tools for agricultural customers.
These supplies will continue to be a challenge for the state.
That’s one reason why PG&E is working with Wexus Technologies to enable conservation of both water and energy, through an energy management software system that is now available to agriculture customers.
Wexus remotely connects pumps, buildings, PG&E electric SmartMeters and water flow meters via cloud technology.
"Water conservation and energy management go hand-in-hand.
We’re glad to be working with PG&E to make water and energy conservation a way of life.” PG&E will continue to work with the agricultural community to manage water and energy use through a variety of existing programs and incentives.
PG&E agricultural customers have saved more than 538 million kilowatt hours and 19 million therms of energy through the company’s energy efficiency programs and rebates since 2011.
That adds up to more than $81 million dollars in rebates in the last six years, since the recent drought first began.
For more information, visit www.pge.com/ and pge.com/news.