Lots of Tap Water Meets Federal Clean Water Mandates
Every year, Californians get a report card from their water department telling them if something is wrong with their water.
These polished brochures typically begin by laying out all the great things water agencies are doing with ratepayer money. It would be easy to just throw them away.
But near the end is series of hard-to-decipher charts that show what sort of contaminants have been found in their drinking water.
These are things, like bacteria, that could make someone sick immediately and others, like disinfectant byproducts, that could give someone cancer over time.
In San Diego, there鈥檚 very little bacteria or carcinogens. Most large water agencies don鈥檛 have major water quality problems. A notable exception is Camp Pendleton, which has聽聽in the water it supplies to Marines. More typical, though, is the city of San Diego鈥檚 water department, which hasn鈥檛 had a water quality violation in聽.
But there鈥檚 a difference between water that meets federal standards and water that is free of impurities. The federal government typically sets聽聽and then a state agency polices those limits.
California has a second set of standards, though. These are ambitious but聽鈥 for how clean people鈥檚 drinking water should be in an ideal world.
Most water districts, including the city鈥檚, regularly fail to meet at least some of those goals.
The state鈥檚 Office of Environmental Health Hazard Assessment establishes the goals. That office is tucked inside the larger California Environmental Protection Agency, known as CalEPA.
For cancer-causing contaminants, the office typically creates a 鈥渙ne鈥恑n鈥恛ne million鈥 standard. That means that no more than one person in a million would get cancer if they drank the contaminant at a certain level for their entire lives.
For example, since 2006, the federal government has said water cannot have more than 10 parts of arsenic per billion parts water. At that level, 2.5 people per thousand could develop cancer. Anything above that is illegal.
California鈥檚 public health goals are stricter, though they鈥檙e unenforceable. The state hopes water districts can produce water that has only one part arsenic per 250 billion parts water. But the goal is so ambitious that lab results can鈥檛 confidently say if the goal is being met or not, according to the state鈥檚 Division of Drinking Water. Because of that, water districts only have to report to the public if they found two or more parts arsenic per billion parts water聽鈥 more than the goal, but less than the legal limit.
The city of San Diego from time to time has more than a few chemicals in its water that exceed these state goals. The most common seem to be Trihalomethanes, a subgroup of compounds known as disinfectant byproducts. They are produced when chlorine or other disinfectants are used to treat water to eliminate bacteria. The city says it has taken steps to reduce these chemicals appearing in water, but they still show up.
Totally eliminating some of the contaminants from water may be impossible or, if possible, incredibly expensive.
Every three years, water districts are supposed to provide a report on how they鈥檙e measuring up against the state鈥檚 voluntary goals. The city鈥檚 Public Utilities Department forgot to do one in 2016 and is planning to submit one belatedly to the state after Voice of San Diego asked about it.
In 2013, though, the city concluded that trying to meet every goal was impractical.
鈥淚n some cases, installing treatment to try and further reduce very low levels of one contaminant may have adverse effects on other aspects of water quality,鈥澛.
For example, the city could use reverse osmosis聽鈥 the same technology used by the new desalination plant in Carlsbad聽鈥 to treat water, but that could have unintended consequences. Treating water that way can reduce its hardness, which can make water corrosive, which can then cause copper and lead pipes to leach those toxic metals into water. (A recent analysis of the effect of the desalinated water on the region鈥檚 water pipes found this sort of leaching was not happening.)
Even if that wasn鈥檛 an issue, the city said, the costs would be hard for customers to bear. It estimated additional treatment expenses would cost customers $537 to $1,028 per year.
The Helix Water District in East County came up with a similar figure聽鈥 $500 to $800 a year for customers.
鈥淭hat鈥檚 really expensive,鈥 Helix鈥檚 director of water quality, Brian Olney, said. Plus, he wondered, 鈥淐an you even get rid of some of these contaminants versus what is some of their long-term actual health concern?鈥
The Environmental Working Group, an activist organization based in Washington, D.C., has been trying to raise public awareness about trace contaminants in people鈥檚 water. Bill Walker, a spokesman for the group, said it鈥檚 a sad commentary that water districts can鈥檛 meet these goals.
The group鈥檚 online database of tap water contamination has caused some confusion for California customers,聽聽than what most agencies disclose to the public, even though it鈥檚 basically the same information. In contrast to the Environmental Working Group鈥檚 database, water agency reports that are sent to households are filled with fine print and inscrutable acronyms.
In 2016, the Otay Water District put out a press release trying to explain that the district complied with federal standards for one carcinogen, chromium-6, even though it was not meeting the state鈥檚 goals. It came in response to another Environmental Working Group report titled, 鈥.鈥
The legal limit for the chemical is 10 parts per billion. The public health goal is .02 parts per billion. 国产视频 three-fourths of the samples tested in Otay exceeded the goal, but not the legal limit.
鈥淎 Public Health Goal is not a boundary line between a 鈥榮afe鈥 and 鈥榙angerous鈥 level of a chemical, and drinking water is frequently demonstrated as safe to drink even if it contains chemicals at levels exceeding their Public Health Goals. Learn more about Public Health Goals,鈥澛.
Walker said his group isn鈥檛 trying to alarm people with its database, but it does want to make sure they鈥檙e informed.
鈥淲e believe that people are smart enough to understand and interpret this information and that government should not be in the business of smoothing over a situation that might indicate some level of concern for some people,鈥 he said.
The group recommends that people who are concerned about something in their water should get an additional home filtration system.
This originally appeared in the Voice of San Diego.