Central Arkansas Water is hiring a contractor to evaluate the Arkansas River as a backup water source in the event its primary water source, Lake Maumelle, is compromised.
The likelihood of a catastrophic event interrupting the raw water flow from Lake Maumelle will increase with the restarting of the Exxon Mobil Pegasus pipeline, the agency wrote in a memo to the utility's board of commissioners.
The board approved an $80,000 contract with Little Rock-based Crist Engineers Inc. at its meeting Thursday to conduct an evaluation of the Arkansas River as an emergency water source.
"We cannot use it as a permanent source because it's designated as a navigational channel, and once it goes below a certain stage you are not allowed to withdraw water, but in an emergency" permission can be sought from the Corps of Engineers, Chief Executive Officer Graham Rich said.
Lake Maumelle is the primary water source for about 450,000 residents in central Arkansas. Approximately 62 percent of the treated water delivered to Central Arkansas Water customers is from the lake. The agency's other source of water is Lake Winona.
A portion of the Pegasus pipeline, which ruptured in Mayflower in 2013, runs through the Lake Maumelle watershed. The rupture caused 3,190 barrels, or 134,000 gallons, of heavy crude oil to be spilled in a neighborhood and surrounding area, including ditches and a cove of Lake Conway, according to the proposed consent decree filed in federal court. The contamination didn't reach the watershed or Lake Maumelle.
After the spill, the pipeline was taken out of service. The southern portion restarted in Texas, but it's unclear when Exxon Mobil will be given authority to restart the northern portion that ruptured.
"While any one of several catastrophic events could interrupt raw water flow from Lake Maumelle, restarting the Exxon Mobil Pegasus pipeline increases the likelihood of such a catastrophic event dramatically," the staff memo said.
Under the contract authorized by the board Thursday, Crist Engineers Inc. will develop several raw water intake and delivery options from the Arkansas River, and at least three will be selected to be studied further.
Completing what is called a preliminary engineering report could take at least eight months.
Metro on 06/12/2015