THE VIRGINIAN-PILOT
Copyright (c) 1994, Landmark Communications, Inc.
DATE: Tuesday, September 13, 1994 TAG: 9409130319
SECTION: LOCAL PAGE: B6 EDITION: FINAL
SOURCE: ASSOCIATED PRESS
DATELINE: RICHMOND LENGTH: Medium: 94 lines
Tiny foreign mollusks are creating big problems for Midwest utilities, and Virginia's two largest power companies are making plans to prepare for their possible spread to the state.
Virginia Power Co. and Appalachian Power Co. both are formulating plans should the zebra mussel, a native of the Russian steppes, spread to the state.
The 1 1/2-inch, distinctively striped shellfish loves to do two things: adhere to hard, submerged objects and reproduce.
Therein lies the rub. Most major lakes and rivers have huge intake pipes for power plants and municipal water plants. In no time, the zebra mussels can plug those pipes.
The nightmare for utility officials is the possibility that the larval stage of the mussel could find its way into a power plant and set up housekeeping in the miles of 1- and 2-inch pipe that make up a plant's system.
``They could bring a plant crashing to a halt,'' said Tim Mallan, Apco's environmental programs supervisor. ``They have the potential of taking isolated units out without a lot of prior notice.''
So Mallan's company has joined with utilities in the Midwest to keep track of the ``little monsters,'' whose reproductive rates are astounding.
The female produces between 30,000 and 40,000 larvae in a two-to three-year span. Scientists have found concentrations of the mussels as high as 700,000 per square meter.
Damage from the mussels in the Great Lakes region, which has the highest concentration of mussels, will reach $5 billion by the end of the century, according to federal estimates.
One Canadian water plant on Lake Ontario had to shut down while workers removed 30 tons of mussels from its 2 1/2-mile-long intake pipe. Detroit Edison removed 40 tons of mussels from intake pipes at its Monroe, Mich., power plant. Cost in both cases was in the millions of dollars.
By hitching rides on barges and pleasure boats, the mussel has spread down the Mississippi River and up the Ohio and Tennessee rivers.
The zebra mussel ``hasn't seemed to have gotten a foothold here east of the mountains yet,'' said William ``Rick'' Willis, a biologist with Virginia Power's water quality department. Willis is part of that utility's task force that has been preparing for the mussel.
Inspections at all plants have been stepped up.
Mallan said divers regularly scour the insides of one plant's 36-inch intake pipe that extends 300 feet out into a river, looking for signs of the tiny saboteur.
Apco, with four power plants in West Virginia, is about to begin talks with state officials there about possible steps to protect its plants. Mallan said zebra mussels have been found in the Kanawha and Ohio rivers, though in small numbers.
For centuries the zebra mussel was confined to the Caspian Sea in Kazakhstan. The cold, nutrient-poor waters of the Russian steppes held the mussel's reproductive powers in check.
Scientists speculate that the mussel came over from Europe in the freshwater bilge water of a freighter in 1988. When the bilge water was flushed out in the Great Lakes, so were the mussel larvae.
``The Great Lakes, with its heavy plankton load and relatively warm water, made a great home for the zebra mussel,'' Willis said.
So would the waters of Virginia. ``They do best in freshwater with elevated pH and calcium,'' Willis said.
A study for Virginia Power by University of Texas-Arlington researchers suggests that the James and Potomac rivers as well as Lake Anna would make nice homes for the mussel. Virginia Power has plants on all those waters.
Willis said the company has begun making plans to fit some of its plants with anti-mussel devices.
Mallan said there currently are three methods of dealing with the pests.
The water in the intake pipes can be treated with chlorine or a bromine, treated with a molluskicide or heated.
``If you maintain the little monsters for eight hours at 105 degrees, they will belly up,'' he said. But all three methods have to be rigorously controlled to limit their environmental impact. Discharge of the heated water could disrupt the ecology of the river or lake, as would returning chlorine-tainted water.
If the water contaminated with a molluskicide were allowed into a river or lake, it could kill the native mollusk population.
Neither utility has calculated the cost of protecting its plants from the mollusk.
``It's not cheap, but it is a whole lot cheaper than cleaning out the pipes,'' Mallan said.
The state Department of Game and Inland Fisheries has set up a monitoring program in southwest Virginia, hoping to get an early warning when, and if, the mussels show up.
The department has enlisted the aid of Department of Transportation bridge maintenance crews, fishermen and volunteers at boat landings to be on the look out for the mussel. by CNB