The Jackson City Council has approved a contract for a corrosion control study as a part of the response to reports of excessive lead levels in some residents’ homes.
This study is one parameter of the water system compliance plan drafted with the Mississippi Department of Health to bring the city’s water supply back into compliance with the Safe Drinking Water Act.
With a 3-2 vote, the contract authorized $291,969 for Trilogy Engineering Services LLC to conduct the study.
A great deal of Mississippi’s drinking water comes from underground aquifers that our protected, for the most part, by confining, sedimentary layers. However, Jackson draws much of its drinking water from surface water sources.
“The majority of systems in the state just chlorinate their water, and that is all they have to do,” said Melissa Parker, spokesperson for the state Department of Health. “For the Ross Barnett and the Pearl (Jackson’s major water sources), it’s constantly something you have to maintain and watch.”
Trilogy’s lead engineer for the study and part owner, Phillip Gibson, said that the first step in the process is getting a plan together to be approved by the Mississippi Department of Health. He estimated that step will probably take between a month and a month and a half.
Trilogy has six months to complete the corrosion control study.
Gibson said the test will likely involve ‘coupons’ suspended in a PVC pipe.
“You take these coupons, they are about one-inch-wide, six to four inches long, and an eighth or sixteenth of an inch thick. They will be put inside some PVC pipe. Then we’ll run some of the areas water through it once a day to stimulate the coupon,” he said.
The coupons are made of lead, copper, or steel. They are weighed before and after the water treatment. By measuring the difference in weights, engineers arrive at a measurement of corrosion in the system.
That information will lead to recommendations on what chemicals would best optimize the water to avoid corrosion in the pipes, Gibson said.
Once the study is completed, the city will consider the recommendations for compliance and what steps it must take to implement the public work projects necessary to reach compliance.
“(Jackson) does not have a history of being out of compliance,” Parker said. “They just need to work on their water treatment which will lead to less corrosivity.”