Discolored water will continue to flow from Potomac River | Environment

Read article : Discolored water will continue to flow from Potomac River | Environment

More Maryland residents will see yellow and brown water flow from kitchen taps, showers and washing machines over the next several weeks as discolored water makes its way from a Potomac River filtration plant into more homes and businesses, utility officials said.

Carla Reid, general manager of the Washington Suburban Sanitary Commission (WSSC), said the discolored water is safe to drink and use but called it “unacceptable” from “an aesthetic standpoint.” She said the problem stems from changes required in the disinfection process due to an unusually large amount of organic matter — decayed leaves, grass and other vegetation — that has washed into the Potomac during recent heavy rainstorms.

WSSC, which provides water and sewer services to 1.8 million people in Montgomery and Prince George’s counties, said that as of Wednesday afternoon, it had received more than 730 complaints of discolored water since Aug. 8. That nine-day total compares with 200 complaints in a typical month.

So far, the problem has mostly affected areas closer to WSSC’s primary filtration plant on the Potomac in western Montgomery, including Bethesda, Chevy Chase, Rockville and Gaithersburg. However, with each passing day, officials said, the water will reach areas farther away, such as northern Montgomery and into Prince George’s.

The discoloration comes from higher-than-usual levels of a natural mineral called manganese. WSSC officials advise against washing clothes with the discolored water because it can stain laundry but say it is otherwise fine.

Manganese is regulated as a “secondary” aesthetic issue for odor and taste in drinking water but not as a public health concern, according to the U.S. Environmental Protection Agency.

“It’s an aesthetic issue that people have to understand, but it’s safe to consume,” said J.C. Langley, WSSC’s director of production. “We want people to understand that we take their safety very seriously.”

Even so, persuading customers to ignore the yuck factor might not be easy.

Mary Hills, of Potomac, said she’s had “yellowish-brown” water two days in the past week. She said she changed the water filter in her refrigerator and that her family is drinking more bottled water. She’s heard WSSC say the tap water is fine, but when brownish water filled her tub last week, she skipped the bath.

“It didn’t make sense to me that it’s clean if it’s discolored,” Hills said. “You don’t look at a tub full of brown water and want to take a bath in it.”

Paul Tibbits Jr., also of Potomac, said he’s still comfortable drinking water that’s passed through his refrigerator filter, even though he’s noticed discolored water in the bathtub twice over the past week. He said he’s accepted WSSC’s assurances that the water is safe, but he’d like some independent testing done as well.

“As the tub was filling up, the water just became darker and darker,” Tibbits said. “My daughter asked why she was taking a bath in brown water.”

WSSC officials say an unusually rainy summer has created a high and fast-flowing Potomac full of more grass, leaves and other organic matter than usual. Like other Washington-area water utilities, WSSC draws water from the Potomac before it disinfects it and sends it out to homes and businesses through pipes. Unlike other local utilities, however, WSSC relies on chlorine to disinfect the river water and control manganese levels.

The problem: When chlorine combines with organic matter, it produces “disinfection byproducts,” which the EPA regulates because of their potential for increasing cancer risks, according to the agency’s website. To limit such byproducts, WSSC officials said, they had to scale back the amount of chlorine they used starting Aug. 8. The lower levels of chlorine are still enough to kill bacteria but leave behind more discoloring manganese, officials said.

“We’ll always side with water quality over an aesthetic issue,” Langley said.

He said he expects that customers will see discolored water for several more weeks, depending on how long the heavy rains continue to carry vegetation into the Potomac.

“We’re asking our customers to be patient with us,” Langley said.

Manganese has been linked to neurological problems in children, but at levels more than 10 times higher than what WSSC is finding in its testing, officials said.

“There’s a big difference in the levels of manganese that cause health problems and what’s in our water,” said Jin Yeong Shin, WSSC’s water quality section manager.

Officials at the Washington Aqueduct, which serves the District of Columbia and the Falls Church area, and Fairfax Water, which serves much of Northern Virginia, said they’ve also seen more organic matter in the river but have had no problems with discolored water. Both said they use other treatment methods that have kept manganese in check.

Shin, WSSC’s water quality manager, said WSSC uses chlorine because it’s good at keeping water safe for long periods. Because WSSC’s distribution system is so large, he said, water can spend a couple of days to a week or so in pipes before reaching its destination.

WSSC’s other filtration plant, which draws water from the Patuxent River, hasn’t had any manganese problems because it has a reservoir that allows organic matter to settle before it reaches the plant, Shin said.

WSSC has had previous problems with manganese. In 2015, the utility received thousands of complaints about brown water. WSSC initially blamed the problem on winter road salt washing into the Potomac and later said the saltier water’s impact might have been exacerbated by the utility’s decades-old iron pipes, which hadn’t been regularly flushed in 15 years.