It takes a lot of work to keep drinking water pure

NEW HAVEN — The instruments the scientists at the South Central Connecticut Regional Water Authority use to test your drinking water are so sensitive, they can detect two parts per trillion of the chemicals, known as perfluorinated compounds, that go into making Teflon.

It is the nonstick coating on pans and is also used on Gore-tex fabric. It is suspected to cause cancer.

But the technicians haven’t found any in the 10 reservoirs or three aquifers that supply drinking water for the 16 cities and towns the water authority serves wholly or in part.

“We haven’t found it in our water,” said Theresa Spalletta, laboratory manager at the Regional Water Authority’s headquarters on Sargent Drive. However, she said, “We do a lot of testing in other utilities as well as ours … as far north as Maine and as far south as Georgia,” and the chemicals, which stick around for decades, have been found in places such as Merrimack, N.H., where a plastics company is located.

The Regional Water Authority recently issued its “2017 Consumers’ Annual Report on Water Quality” — just in time for Drinking Water Week this week — and while they’re bound to find a bit of bacteria or a few microbes, the 118,000 customers of the water authority (composed of 430,000 consumers) can be assured that the water flowing from the tap is just about as pure as can be.

According to the report, the Regional Water Authority meets or exceeds every regulatory standard set by the Environmental Protection Agency and the state Department of Public Health. In 2017, it conducted more than 110,000 tests on more than 10,000 water samples.

But making sure that pure, clean water streams out of your tap is a complex process. Coagulants are added to combine with floating particles so they sink to the bottom of the filtration tanks. Filters contain activated carbon that removes organic material and compounds that give the water an unappealing odor or taste. Chlorine disinfects the water, and chemicals are added to coat the water pipes leading to your home so they don’t corrode and allow lead and copper to leach into the water.

Fluoride is added to the water because it helps prevent tooth decay, but too much can be a problem and it can get into the water from factory discharges, so it’s monitored, too.

It’s a lot of water to treat. “Our average output for a day is 45 million gallons,” said Bryan McLean, operations team lead at the authority’s headquarters on Sargent Drive. “Our maximum day would be 70 (million) to 75 million gallons. That’s during July. That’s our hottest month.” Ninety-one percent of the water authority’s customers are residential.

The sources the water authority draws from range from the Housatonic River aquifer (an underground saturated area) in Derby and Seymour, which draws from as far as Shelton to the Hammonasset Reservoir, which lies on the Madison-Killingworth town line. Lake Gaillard in North Branford alone processes 5 million gallons of water a day through 16 filters. Water flowing into those filters goes through a turbine generating about $150,000 in electricity a year.

Spalletta said the water authority tests for organic and inorganic chemicals, as well as microbials. Ammonia, phosphates and nitrogen in the water “will feed algaes, so you want to keep an eye on that because you don’t want algal blooms in your reservoir because it will cause filter clogging and taste and odor issues.”

However, phosphate is one of the chemicals added to the water later to help coat pipes.

To make sure the clearest water goes into the filtration system, there are intake pipes at different depths — four at Lake Gaillard. “In the summer you want cooler water so you go to a lower depth. You don’t want algae problems,” which might be an issue at a shallower depth, Barger said.

Besides causing odor and taste problems, growth of algae and other organisms make the water less clear, an issue water experts call turbidity.

Water samples are tested for bacteria, “but specifically coliform bacteria,” such as E. coli, which are cultured in a petri dish, according to microbiologist Steve Cappella. “E. coli has a specific type of chemistry,” he said. “If there is to be a sample that comes in, if it were to be positive, we would ‘type it out’ — run it through tests that take several days.”

The lab technicians test for nitrites and nitrates, high levels of which can cause a condition called blue baby syndrome, in which the blood cannot carry enough oxygen.

Your water is checked for trace minerals, including iron, manganese, zinc, barium and beryllium, Spalletta said. The water authority tests for calcium and magnesium, the main causes of hard water, which can contribute to cardiovascular disease, growth issues and reproductive problems, according to the National Institutes of Health.

But the biggest concerns are lead and copper, especially lead, which can cause brain damage and for which the “maximum contaminant level goal” is zero. The EPA established the Lead and Copper Rule in 1991, which limits the amount of copper in drinking water to 1.3 parts per million for copper and 15 parts per billion in lead in no more than 10 percent of the water supplies.

The testing is done at the tap. “We actually send out letters … and people can volunteer to have their water tested,” Barger said. According to Kate Powell, communications and outreach manager, “At this point, we have about 75 that volunteer.”

To test the water, the customer can’t use their water for four to six hours. “Most people (say), ‘No thank you,’” Barger said.

Spalletta said “There’s been a lot of discussion on pharmaceuticals, endocrine disrupters,” which the EPA had tested between 2012 and 2015. But they don’t seem to pose a threat and “it doesn’t seem like anybody’s testing for them at the current time,” she said. The federal agency “didn’t see enough to be a problem.”

Still, “there’s 17 different federal rules that regulate water quality and some of these are somewhat exotic,” said Thomas Barger, manager of water quality and treatment for the RWA. “If you go to certain areas of the country where they’re naturally occurring, they can be a problem.”

Radon, for example, isn’t regulated and is only detected in aquifers, because it naturally disperses from reservoirs.

While chlorine disinfects the water, it also forms byproducts that must be removed, with names like trihalomethanes — chloroform is one — and haloacetic acids, all possible carcinogens. “You have organic matter in the water and when you add chlorine to it these are some of the products it forms,” Barger said.

Other potential dangers that the water authority tests for are pesticides, herbicides and phthalates, which are used in plastics, Barger said.

The annual report that was mailed out last week lists a number of exotic-sounding chemical compounds, it doesn’t include everything the water authority tests for. “It’s complicated enough now,” Powell said.

“The RWA tests for more things more often than we’re required to do,” Barger said. “We have an ethical obligation really. … We’re not making cigarettes here.”