Controlling Mussels May Cost Utilities

Mussels are a water treatment headache for utilities across the country this summer.

"Quagga mussels are documented to be present in the Central Arizona Project (CAP) Aqueduct water delivery system from the Mark Wilmer Pumping Plant in Lake Havasu to the CAP canal mile 200 in Apache Junction. They are suspected to be present in the CAP Aqueduct from canal mile 200 in Apache Junction to the terminus at canal mile 337 south of Tucson, as well as the Salt River Canal System, beginning at the CAP Interconnect below Granite Reef Dam," Sonoran News reported.  

Mussels are a pest for customers and utilities alike since they sometimes lead to higher water bills. In Texas, mussels invaded Lake Ray Roberts and Lake Texoma, forcing one water district to spend millions on a new pipeline.

"Millions of tiny mollusks in two North Texas lakes will raise the cost of water in the region as soon as this summer and experts say they could do the same in other parts of the state," NPR reported last year. 

Many utilities are trying to weed out mussels during the treatment process. Companies use screens and micro-strainers to pre-treat the mussel problem, the Alabama State Water Program noted. Fixed bar screens are used to remove bigger debris, fish and mussels before they enter treatment, where they can damage pumps.

"Many utilities have developed special cleaning techniques for their submerged intakes because screen clogging from zebra mussels has become a real problem for them. Traveling screens is one approach used to reduce the buildup of zebra mussels," the program said.

Efforts to contain mussel populations have emerged at various levels of oversight. 

The East Bay Regional Park District in California is trying to educate the public about the threat mussels pose to the water supply. Since mussels settle in massive colonies, "they can block water intake that can affect municipal water supplies, agricultural irrigation systems and power plant operations," the district says in its literature. 

The Arizona Game and Fish Department has implemented a "Don't Move A Mussel" campaign to educate boaters that mussels often colonize new areas by riding ballast water discharges from ships.