NEW HANOVER COUNTY — Nearly two years ago, 30,000 customers of the Cape Fear Public Utility Authority awoke to robocalls and an all-caps email subject line “DO NOT DRINK THE WATER.”
The email and phone calls, sent just after 6 a.m. on April 25, 2018, told residents serviced by the Cape Fear Public Utility Authority (CFPUA) Richardson Nano Groundwater Treatment Plant not to drink or cook with water due to an “overabundance of fluoride,” and included the warning that “failure to follow this advisory could result in illness.”
The Richardson plant provides service to much of northern New Hanover County, including the Murrayville, Wrightsboro, Porters Neck, and parts of Castle Hayne and Ogden areas.
Later on the day of the spill, state officials confirmed fluoride levels in northern New Hanover County had spiked, reaching 8 milligrams per liter — four times the Environmental Protection Agency’s recommended level (2 mg/L) and double the enforceable federal limit (4 mg/L). The spike was over ten times CFPUA’s own target level of .7 mg/L (which is also the level recommended by federal public health authorities).
It’s worth noting that most of the health effects of excessive fluoride consumption — including fluorosis, which involves weakened bones — are chronic and involve long-term exposure. Acute toxicity requires much higher doses: many studies put the ‘probably toxic’ dose of fluoride at around 5 mg per kilogram of body weight (or 2.27 mg per pound). More severe toxicity, including potential death, is cited at higher levels, 7.3 mg per pound for children, and 14.5 mg per pound for adults.
To put that in perspective, to experience toxic effects a 160-pound adult would have to consume 363 mg of fluoride — at the elevated levels from April 2018, that would require consuming 45 liters (a little over 11 gallons) in a relatively short period of time. Even the average 45-pound 6-year-old boy would have to consume over 3 gallons.
CFPUA officials later confirmed a mechanical failure caused the spike, leading the utility to discontinue adding fluoride at the Richardson nanofiltration plant.
CFPUA officials said routine tests conducted around 5 a.m. on the day of the spill detected elevated fluoride levels. According to CFPUA, as soon as these levels were detected the fluoride system was immediately shut down and by 10 a.m. levels had returned to normal. Because CFPUA aggressively flushed the pipes to remove fluoride, ‘boil warnings’ were issued in case bacteria had built up in the lines — these warnings lasted the rest of the day (and in smaller areas, into the following morning).
Further investigation traced the mechanical failure to the evening of the previous day, when the plant was not pumping water, according to CFPUA meeting minutes.
Shortly after the spill, CFPUA proposed a $5 credit for affected customers, which was approved at the utility board’s May 9, 2018 meeting.
On Tuesday, January 28, CFPUA resumed fluoridating water at its Richardson plant.
“The resumption of fluoridation at Richardson follows work to modify the system at Richardson that is used to add fluoride to drinking water and add backup controls,” according to a release from CFPUA.
CFPUA has fluoridated the water at the plant since 2010. The Sweeney Water Treatment Plant — CFPUA’s largest water treatment facility, which serves about 80% of its customers — has used fluoride since 1955; fluoridation at Sweeney was not interrupted in April 2018.
You can read CFPUA’s press release, below:
CFPUA has resumed adding fluoride to drinking water at its Richardson Water Treatment Plant prior to distribution, effective Tuesday, January 28.
Richardson, which provides water to the second-largest of CFPUA’s three drinking water-distribution systems, serves customers in northern New Hanover County, including Murrayville, Wrightsboro, Porters Neck, and parts of Castle Hayne and Ogden. Its source water comes from groundwater wells.
Fluoridated water is among the “10 great public health achievements of the 20th century,” according to the U.S. Centers for Disease Control and Prevention (CDC). “Drinking fluoridated water keeps teeth strong and reduces cavities (also called tooth decay) by about 25% in children and adults,” the CDC states on its website. “By preventing cavities, community water fluoridation has been shown to save money both for families and for the U.S. health care system.”
The resumption of fluoridation at Richardson follows work to modify the system at Richardson that is used to add fluoride to drinking water and add backup controls.
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CFPUA ceased fluoridation at Richardson in April 2018 after elevated levels of fluoride were detected in treated water. As a precaution, CFPUA temporarily shut down Richardson and stopped distributing water from the plant for several hours. Normal operations at Richardson resumed later in the day, but without the fluoride feed. Tuesday marks the first time since then that fluoride has been added to treated drinking water at Richardson. CFPUA routinely tests for fluoride in our drinking water to ensure it remains within acceptable concentration ranges.
Water treated at Sweeney Water Treatment Plant, which provides 80 percent of CFPUA’s drinking water, has continued to be fluoridated.