The two water utilities in Arkansas with lead concentrations above federally actionable levels are taking steps to improve the water for their customers.
In 2015, Harrison Waterworks and Delight Waterworks had water samples taken from customers' homes that tested above the level the U.S. Environmental Protection Agency says should prompt action to reduce them. It wasn't the first year of above-action-level samples for either utility.
Since the first of the year, Delight has increased the amount of the corrosion inhibitor zinc orthophosphate in its water supply to protect connection pipes and plumbing in people's homes that might be leaching lead into the water, and Harrison plans to inject zinc orthophosphate into its water for the first time later this year.
"We started seeing some elevated lead levels at a few customers' taps over the years," Harrison Public Works Director Wade Phillips said. "It's kind of to the point where we need to do something about it so it doesn't become a bigger problem."
In children, drinking water contaminated with lead levels above the EPA action level can cause delays in mental or physical development, including deficits in attention span and learning abilities, according to the Arkansas Department of Health.
Unlike many other contaminants, lead often is introduced into a water supply by the corrosion of rusty pipes, solder used to join pipes, or faucets that the water travels through after it leaves a utility's treatment plant.
Congress banned the use of lead solder containing greater than 0.2 percent lead and restricted the lead content of faucets, pipes and other plumbing materials to 8 percent in 1986 to cut down on lead poisoning, which occurs when the metal builds up in the body, often over a period of months or years.
Department of Health records indicate the 90th percentile results of the water tests in Harrison and Delight in 2015 were 23 parts per billion, well above the action level of 15 parts per billion.
A 90th percentile score of 15 parts per billion means 90 percent of the sample results were below that level, while 10 percent were above. To be clear, the EPA has not determined any amount of lead in water is safe, only acceptable.
After a utility has a 90th percentile score exceeding the action level, the utility or the Arkansas Department of Health is required to research the quality of the water in the system. After six months, the utility's water will be tested again, and if the results show the 90th percentile score does not exceed action level, the utility does not need to take any action to reduce lead levels under the EPA's 1991 Lead and Copper Rule, said Teresa Lee, a Health Department statewide supervisor for transient water systems. If the utility's 90th percentile score is above the action level a second time, the utility must find a way to fix what is causing lead to get into people's drinking water.
The Lead and Copper Rule is under scrutiny after high lead concentrations were discovered in the drinking water in Flint, Mich., and the EPA is actively trying to develop a revision of the rule.
A point of discussion among many is the amount of time agencies have to respond to the test results, said Jeff Stone, director of the engineering section at the Health Department. For now, the department is trying to follow the rule to the letter, he said.
In 2014, Harrison Waterworks, which serves about 16,000 people in Boone County, had four water samples that tested above the action level. Six months later, the system had none. But in 2015, 11 of 60 samples tested over the limit.
That's when the Department of Health gave the city until November 2016 to come up with a solution.
Solutions to reduce lead levels are typically the introduction of zinc orthophosphate as a corrosion inhibitor into the water supply or the raising of pH levels, Lee said. A lower pH is typically more acidic and more corrosive.
Later this year, Harrison Waterworks will inject zinc orthophosphate into the water at a rate of five parts per million for four months, Phillips said. After four months, the chemical should create a protective lining on water pipes both in the utility's system and in the plumbing of people's homes that will prevent the corrosion of the pipes that is causing lead to leach into people's drinking water, Phillips said. The utility will then reduce the amount of orthophosphate being injected into the water to two or three parts per million.
Phillips said lead levels were elevated at the taps of 11 homes in 2015 and that it was likely the result of old plumbing corroding and emitting lead into the water. He said the city had tested the water in the utility water mains -- before it enters people's homes -- and hadn't seen lead above action levels.
The project will cost $50,000 up front, according to water distribution manager Brad Stone, and will cost about $15,000 to $23,000 annually to inject lower amounts of zinc orthophosphate permanently. The project was approved by the approval of the Harrison City Council in February.
After repeatedly exceeding action levels, Delight Waterworks, which serves about 1,500 customers in Pike County, began injecting zinc orthophosphate four years ago into its water supply to keep water mains and the pipes in people's homes from corroding. Recently, the Arkansas Department of Health asked the utility to increase its levels of zinc orthophosphate from 1 part per million to 1.5 after three of 20 test samples registered over the action level in 2015.
Delight Waterworks superintendent Jason Campbell noted that the latest sampling only fell short of drinking water standards by one test. In 2014, only one sample surpassed action level, and the water system's 90th percentile score was 11 parts per billion, according to Arkansas Department of Health records.
Campbell also said he believed the lead levels were caused by old plumbing in people's homes.
"It's the lead from household plumbing, old plumbing," he said. "We do not have lead in our source water."
"We're still sampling a lot. We're still monitoring the situation," Campbell said. "I wouldn't say it's a complete success yet."
Information for this article was contributed by Chelsea Boozer of the Arkansas Democrat-Gazette.
Metro on 03/28/2016