Cities on alert after one city's water intake system is nearly halted

 

Cities across the Midwest are on alert after zebra mussels nearly halted one city's water intake system and continue to threaten other public supplies and waterways.

"Some utilities are being overwhelmed," says John Mitchell, director of the water practice at Burns & McDonnell. "Planning for the inevitable invasion of these mollusks is critical. Almost every surface water supply in the Midwest is at risk."

Zebra mussels are small, dark or striped mollusks capable of altering ecosystems and destroying surface water supply infrastructure. The mussels attach to hard surfaces such as rocks, boat hulls and any other hard surface including water production infrastructure and are very difficult and costly to remove. The aquatic hitchhikers clog power plants, industrial, and public drinking water intakes and are projected to cause billions of dollars in damage during the next 10 years.

"Utilities in the U.S. are already spending about $100M annually to deal with zebra mussels," says Joe Werner, associate environmental scientist at Burns & McDonnell. "Also, despite efforts of state and federal agencies, zebra mussels have spread throughout the Midwest and are continuing to expand their invasion into water supply lakes and rivers."

In the past six months, Burns & McDonnell has been flooded with calls to help mitigate the mollusks that are thriving in lakes, reservoirs and river systems.

Burns & McDonnell has a specialized team with decades of experience designing and implementing customized plans for zebra mussel removal from waterways and public intake systems.

"Water treatment plant intake areas provide an ideal environment for zebra mussels because they thrive on the plankton carried by the constant flow of the water," says Matt Baker, an environmental engineer in the Burns & McDonnell Water Group. "Before you know it they build up on intake screens and eventually bind intake screens, pipes and pumps altogether."

City officials in Council Grove, Kan., quickly responded when zebra mussels formed a 2-inch-thick colony along the walls of an intake and inside pipes that carry water from the lake to the city's treatment plant. Officials immediately addressed the flow issues using generators to keep the water pumping and urging residents to restrict water usage until Burns & McDonnell crews could address the emergency. This has allowed city officials to develop a plan for long-term protection of the public water supply.

"Luckily they were able to take care of the issue in a timely manner because of quick thinking by the city staff," Baker says.

Female zebra mussels can produce more than a million eggs each spawning season. They hatch into microscopic larvae called veligers. As they mature, they grow shells, which are sharp and dangerous to barefooted swimmers. The mollusks got to the United States in ship ballast water. They are spread as the water containing larvae flows into another reservoir or is transported by boats and other objects.

"Additionally, the quagga mussel — similar to the zebra mussel — is causing similar problems as it migrates from the Midwest to the western United States," Werner says.

Zebra mussels have been discovered in numerous Kansas reservoirs including Perry, Smithville, Council Grove City Lake and the El Dorado Reservoir. In Missouri, the mollusks have been found in the Missouri River, Lake of the Ozarks on the Osage River, and in Bull Shoals Lake and Lake Taneycomo in the White River system. Zebra mussels have also migrated to waterways in Iowa, Oklahoma, Arkansas, Nebraska and Texas.

"If you have zebra mussels in your lake, they will eventually be in your water intake system, and you need a plan to deal with them," Baker says. "Every surface water source is at risk for invasion, so a contingency plan is a vital necessity. Even cities without an immediate problem like need to take precautions."

About Burns & McDonnell
Founded in 1898, Burns & McDonnell is a 100 percent employee-owned, full-service engineering, architecture, construction, environmental and consulting services firm. Burns & McDonnell is currently the 23rd largest AEC firm in the Engineering News-Record top 500 ranking. With the multi-disciplinary experience of more than 3,400 professionals in more than 30 regional, national and international offices, Burns & McDonnell plans, designs, permits, constructs and manages facilities worldwide with one mission in mind — to make our clients successful.

SOURCE: Burns & McDonnell