A water quality report released by the city Wednesday indicates the city’s water supply surpasses the regulations set by Tennessee and the Environmental Protection Agency. The report, which covers January 2016 through December 2016, must be released by the city every year.
Tom Witherspoon, the director of Water and Sewer Services in Johnson City, said many of the guidelines are set by the federal government. States have the option to make these standards stricter, but they cannot make them more lenient.
“I think we’re very fortunate,” Witherspoon said. “We have two outstanding water sources. ... This (city) commission and previous commissions continue to reinvest in the water infrastructure here that serves our customers.”
Johnson City retrieves its water from the Watauga River and Unicoi Springs. It has two drinking water treatment plants and 947 miles of water lines.
Among the items tested, the report said the Johnson City water supply contains acceptable levels of haloacetic acids and trihalomethanes, which are byproducts of drinking water chlorination and disinfection, and acceptable levels of inorganic contaminants like copper, fluoride and lead.
The city’s water contains:
• 0.24 parts per million of copper, which is below the limits set by the EPA and the Maximum Contaminant Level Goal of 1.3 parts per million. The Maximum Contaminant Level Goal is the level of a contaminant in drinking water below which there is no known or expected risk to health.
• 0.7 parts per million of fluoride, which is below the MCLG health goal and EPA limit of 4 parts per million.
• 1.2 parts per billion of lead, which is below the EPA limit of 15 parts per billion.
The MCLG health goal for lead is 0 parts per billion, which Witherspoon said reflects the belief among the medical community that there is no safe level of lead. Water leaving the Johnson City treatment plants does not contain lead, but it could pick up trace amounts of lead or copper when it travels through the plumbing system. Johnson City doesn’t adjust the pH of its water supply, which is slightly above 7, to change the corrosiveness of the water. The city adds a corrosion inhibitor.
Chlorine, a disinfectant used to control microbes in the water supply, is also present in the water supply at an acceptable level. The report said the city’s water contains 2.02 parts per million of chlorine, a result below the Maximum Residual Disinfectant Level (also known as the highest acceptable level of disinfectant allowed in drinking water) and the Maximum Residual Disinfectant Level Goal (also known as the level of a contaminant in drinking water below which there is no known or expected risk to health).
Witherspoon said the frequency at which lead and copper are sampled is different from some of the other contaminants, which is why the lead and copper samples in the 2016 report are from 2014. According to the report, the concentration of these contaminants does not change regularly. The frequency at which the contaminants are sampled is set by state and federal agencies.
While the report’s findings are promising, one of the additives listed in the report, fluoride, has been at the center of a heated debate in the region.
In February, the Jonesborough Board of Mayor and Aldermen voted to remove fluoride from the town’s water supply. Proponents argue the additive, at an acceptable level, is a helpful means of promoting dental health.