Four years after Mooresville started requiring business owners to put a special valve on their water connections to protect its water supply from harmful substances, the town is telling some residents to follow suit.
The valve, called a backflow preventer, is designed to stop the reverse flow of undrinkable water from entering the public drinking supply. Late last month, the town sent letters to some 1,000 residential water users with irrigation systems or swimming pools using automatic water dispensers, instructing that they have them in place by the end of May, or face the prospect of having their water shut off.
The precautionary measure might rile some residents, given that buying and installing the device can cost roughly $1,000 or more.
“It’s a hard sale,” said Barry McKinnon, public utilities director for Mooresville. “It’s not something that people look forward to.”
Long considered a risk to public health, back flow is caused by a drop in water pressure as a result of events such as a water main break or frozen pipes.
Every state has in place regulations to protect public water supplies, as part of the 1974 Safe Drinking Water Act, including a mandate for the devices. Among nearby local governments requiring them are Charlotte, Concord and Salisbury.
But monitoring them in some cases has proved ineffective, said Roy Dillard of the American Backflow Prevention Association, an international organization based in Texas.
While many local governments require them, ensuring the devices are installed and inspected on an annual basis has proved difficult in some cases, he said. “That’s what the problem’s been,” he said. “It just isn’t being done.”
Supplying an average of 4 million gallons of water per day, Mooresville has faced no major threats to its water supply in recent memory, officials said.
But the backflow preventers received some validation last spring, when a water main break caused a sharp drop in pressure in the town’s water system, McKinnon said. After assessing the damage, officials concluded that if it weren’t for the devices, the pressure drop might have sucked harmful substances from nearby commercial and industrial properties into the water supply, he said.
In Mooresville, commissioners passed an ordinance in 2007 requiring its roughly 2,500 commercial and industrial water users to have the device, in response to state regulations passed that year.
The measure, which the public utilities department did not start enforcing until 2011, initially included operations posing the greatest risks, such as gas stations and restaurants. All have since complied, officials said.
The requirement for the residential water users was also part of that ordinance.
Under it, residents with irrigation systems must have the device installed and inspected by May 31, said Angiel Boliek, who runs the town program requiring the devices. The state and federal government deem those systems highly hazardous.
For those with the swimming pool dispensers, they must have them in place and have an inspection scheduled by that date.
The town plans to send another round of letters to residents in April, before issuing a “final reminder” in May, Boliek said. If residents fail to comply, the town could shut off their water within a couple of months.
Boliek said she has encountered minimal opposition so far. “I explain to them why it needs to be there,” she said of the device, noting that the town plans to eventually require all of its 11,500 residential water users to have them.
The devices must pass an initial inspection by the county. That, along with buying and installing them, can cost between $800 and $1,300, said Bob Zarybnicky, who runs a Lake Norman plumbing company.
“It really makes sense,” he said of the devices, which a licensed plumber must install. Those who already have them are exempt from the requirement, though they are responsible for replacing them should they stop functioning or fail to pass an annual inspection by the town.
Jake Flannick is a freelance writer. Have a story for Jake? Email him at firstname.lastname@example.org.