CBWD agrees to increase pH to reduce corrosion


Dwayne Allen, director of Public Works for Eureka Springs, said recent testing results from samples tested by the Arkansas Department of Health indicate that levels of lead and copper in the city’s water have not increased since fluoridation chemicals were added starting in the summer of 2015.

In addition to concerns about the safety and effectiveness of adding fluoride to drinking water, opponents have had concerns that fluoridation chemicals would increase leaching from old water pipes that contain lead solder. While recent testing results do not show an increase in lead leaching, Allen said water-testing results show there is a need to decrease the water’s corrosivity.

Allen said the Carroll Boone Water District (CBWD), which supplies water to Eureka Springs, Berryville, Harrison and other cities, has reconsidered its position and agreed to adjust the pH slowly.

“But at the same time, they are changing the Memorandum of Understanding with member cities to delete any requirement to provide non-corrosive water,” Allen said.

Another tactic to reduce corrosivity is adding orthophosphates. Allen said Carroll Boone Water District would not be adding orthophosphates, but has agreed to add lime to increase the pH, thereby reducing corrosion.

“If that process is not successful, the Arkansas Department of Health may require orthophosphate addition to individual systems,” Allen said. “At this time CBWD has not committed to any action besides the pH adjustment.”

Allen said the state, while forcing water plants to add fluoride, does not see the need to have them meet corrosion requirements at a much-reduced cost, but would prefer to force small systems into additional capital and maintenance costs, thus reducing their ability to remove lead. He said he has completely revised the city’s Lead and Copper Sampling Pool by verifying the year residences were constructed and ruled out any with known plumbing upgrades. Newer plumbing does not use lead solder.

“The new the Lead and Copper Rule (LCR) must recognize the substantial funding required at each level to keep our water safe,” Allen said. “Carroll Boone is increasing rates by .05 per thousand gallons at the first of 2018, which the city will absorb without any rate adjustment.”

The Environmental Protection Agency announced an upgrade to the LCR by 2017. Allen said that deadline was just recently extended into 2018 adding the need to get states more involved in the process.

“I do not believe it will be a short process without a deadline in place,” Allen said. “The Lead and Copper Working Group met between March of 2014 and June of 2015 and issued its recommendations to the U.S. EPA’s revising of the LCR is still not complete.

“We know there is not a safe level of lead exposure. The LCR should remain a treatment rule, but should be improved based on scientific knowledge discovered since the current LCR became law. Corrosion control treatment is complicated and will vary based on specific circumstances of each water system. Thus, regular guidance by the EPA to the states and public water systems is needed. I hope for a health-based, household action level that triggers a report to the consumer and to the applicable agency for follow up.”

Allen said lead contamination caused by corrosion from lead service lines and lead solder and brass fixtures in household plumbing is increased by low pH, high flow, high temperatures, high dissolved oxygen, or high dissolved or suspended solids. Water with high alkalinity can form a calcium carbonate scale on the inside of pipes, which will reduce leaching of the metals from the pipes. But he said it is important to be careful not to create a scale to the point flow is reduced or sulfur-reducing bacteria is formed causing microbiological induced corrosion.

Eureka Springs area residents opposed fluoridation for 30 years, and have continued to try to remove the state mandate that fluoride be added to drinking water supplies. However, legislation to allow local control over the decision to fluoridate has repeatedly failed to make it out of the Senate Public Health, Welfare and Labor Committee.