Tests of water that JEA supplies to about 700,000 Jacksonville-area customers found elevated amounts of a possible carcinogen about one time in seven during recent years, records compiled by an activist group show.
The water met federal safety standards, including a standard for safe levels of the possible carcinogen, a family of chemicals called total trihalomethanes.
But the average level of trihalomethanes was more than twice the average among utilities in Florida and nationally, according to data being released Wednesday by the activist Environmental Working Group.
The group collects information that almost 50,000 utilities report to environmental agencies. It’s posting updated information Wednesday in an online “tap water database” about tests from 2010 to 2015.
It’s not clear why trihalomethanes are more common in JEA’s water, but their presence is a direct result of using chlorine to disinfect water the utility pumps from Florida’s aquifer. Trihalomethanes are produced when chlorine mixes with the sort of organic materials that will always be found in water pumped from the ground.
Kevin Holbrooks, JEA’s director of laboratory services, said the utility has met federal safety standards as long as he’s worked there, and that the numbers the database shows are “far within the regulatory limits.”
That’s not the point, said Kevin Cook, president of the Environmental Working Group.
“Just because your tap water gets a passing grade from the government doesn’t always mean it’s safe,” Cook said in emailed comments about the database. He said it’s important to listen to scientists’ warnings about long-term effects of some chemicals thzat are commonly used.
Activists have said trihalomethanes are linked to a higher loing-term risk of bladder cancer.
Some utilities use alternatives to chlorine, but every kind of disinfectant has downsides that people have to choose between, Holbrooks said. Some utilities disinfect water with hypochloride, he said, but doing that means dealing with lots of ammonia and a separate set of problems.
Using less chlorine would lower trihalomethane counts, but another set of regulations requires JEA to keep a constant residual amount of chlorine in its supply pipes, Holbrooks said.
The length of JEA’s water pipe grid, stretching more than 4,300 miles, could add to the counts, because water that sits undisturbed longer will develop more trihalomethanes. In neighborhood where there’s been very little water use, he said, JEA crews sometimes open fire hydrants just to get water moving again.
Rules the U.S. Environmental Protection Agency set for utilities are supposed to deal with that. Utilities changed the places water is tested a few years ago to be sure they caught older, stale water.
Since testing records were updated to meet the new rules in 2013, 17 out of 117 water samples JEA usually collected quarterly had trihalomethane levels above an EPA safety threshold of 80 parts per billion. EPA safety standards are based on annual averages, so trihalomethane levels are judged by four quarterly samples averaged together.
JEA routinely flushes pipes where chemical levels are too high and re-tests to see that the problem has been addressed, said Kim Neumann, a senior environmental scientist for the utility.
JEA officials were nonplused about the Working Group database, noting that it uses information JEA already includes in its own annual report posted online.