An ever-evolving "rapid response plan" previewed Thursday aims to marshal available forces quickly and efficiently to combat any identified Columbia River basin invasion of environment- and economy-changing zebra and quagga mussels.

The invasive aquatic species have wracked areas of the Midwest and East, attaching themselves to infrastructure and multiplying rapidly to form dense colonies. One recent survey estimates $268 million in zebra mussel-related impacts just to drinking water and power plant facilities from 1989 to 2004.

The establishment of nonnative mussel populations in the Columbia basin would pose "major environmental" problems for the Columbia basin, a region that depends as much as any on harnessing its surface water, according to the NOAA Fisheries Service's Mark Schneider, a member of the 100th Meridian Initiative Columbia River Basin Team that is building the rapid response plan.

The group includes federal, state, tribal, industry, university and non-governmental organization representatives. Schneider, the U.S. Fish and Wildlife Service's Paul Heimowitz and Stephen Phillips of the Pacific States Marine Fisheries Commission updated the Regional Forum's Implementation Team Thursday on the plan's development.

The IT -- made up of representatives of state and federal fish management and hydro power agencies – is part of a Regional Forum created to help guide actions that improve survival of salmon and steelhead listed under the Endangered Species Act.

"The economic impact of zebra and quagga mussels to the hydropower system on the Columbia and Snake Rivers is of particular concern," according to a draft plan now being circulated for review and comment. The draft can be found at http://100thmeridian.org/ColumbiaRT.asp

"If introduced into the CRB, the mussels could affect all submerged components and conduits of this system, including fish passage facilities, navigation locks, raw water distribution systems for turbine cooling, fire suppression and irrigation, trash racks, diffuser gratings, and drains."

Fish operations, as well as other federal hydro system operations, "are going to have to change significantly" if zebra and quagga mussels become entrenched, according to the Heimowitz, co-author of the draft document with Phillips. Irrigation, municipal water supply and other infrastructure could also be affected, and a mussel invasion also has the potential to collapse the existing food chain for native creatures.

A 2005 study commissioned by the Bonneville Power administration estimates that the one-time cost for installing zebra mussel control systems at hydroelectric projects could range from the hundreds of thousands of dollars to over $1 million per facility.

"When additional study estimated maintenance costs over five years, the cost estimate for 13 hydroelectric projects grows to $52,704,301," the draft response plan says. "The costs of zebra mussel control cited in this study will increase significantly, potentially 2-3 fold or more, when mitigation costs for juvenile and adult fish passage facilities, and maintenance and cleaning down time for systems and equipment including (but not limited to) generators, fire suppression/deluge, heating, ventilation, and air conditioning equipment, drain galleries, sumps, oil water separator and forebay/tailwater sensors are factored in."

The potential for a mussel invasion has long been considered, but a greater urgency now prevails. Until a year ago, no known quagga or zebra mussel populations existed in waters west of the 100th Meridian, which runs north and south through the country's midsection.

In January 2007, live quagga mussels were found living in the Southwest's Lake Mead. Since, quagga mussels have been found in other waters of the Colorado River Basin, including Lake Mojave and Lake Havasu and water bodies associated with the Colorado River Aqueduct and Central Arizona Project.

"This new invasion represents a tremendous jump across the country, and presents a more imminent threat that a Dreissena species will be introduced into Columbia Basin waters," the draft plan says.

The invasive mollusks most often travel from place to place by boat and trailer, attaching themselves to water craft in one body of water and transplanting themselves in the next.

"Zebra mussels have been found on recreational water craft entering the Columbia River Basin (CRB), such as a zebra mussel-infested boat intercepted after traveling through Oregon en route to British Columbia in 2007. In fact, there were over 100 interceptions of watercraft with attached zebra mussels in western states during 2004-2006," the plan says.

The state of Washington has led the Northwest in preparedness, declaring illegal the transportation of zebra mussels and other invasive species into the state. Its Legislature last year expanded authority and funding for random inspections and field checks of all watercraft.

The state's first citations for illegally transporting zebra mussels were issued in October to two out-of-state trucking companies hauling large boats to the Pacific coast. Live zebra mussels were found attached to boats being transported by a hauler from Ontario, Canada, and another from Iowa. The zebra mussels were spotted during Washington State Patrol commercial vehicle inspections at a Washington-Idaho port-of-entry weigh station east of Spokane.

Fines of up to $500 were imposed, Schneider said. The new law allows fines of as much as $5,000.

"They've kind of moved from the awareness phase to the action phase," Heimowitz said.

The plan is intended allow quick action if invasive mussel populations become established. It would include a standing response organization, the identification of resources that can be called on in an emergency and legal authorization to act. The group will ask, likely within the year, agencies, tribes, state governors' offices and others to officially sign on to the plan.

"Some of the things we may need to do here have serious implications," Schneider said.

The plan is intended to assure that "a diverse set of integrated response tools, including chemical treatment in natural systems, are readily accessible to manage a population if it is discovered." Tools listed include thermal shock, freezing, oxygen starvation, desiccation, UV radiation, predation and electrical and acoustic deterrents.

During an October meeting the group created a potential scenario in which mussels were detected at a boat ramp on the Columbia upstream of Bonneville Dam on the Washington shore. The exercise was intended to test drive the organization structure and action plan and it seemed to work, though it and other discussions prompted more refinements to the response plan.

"That's what we were hoping for," Heimowitz said of a general agreement that the group was on the right path.

A recent Oregon State University research paper indicates that calcium, or the lack thereof, in Columbia basin waters may help discourage a zebra or quagga mussel invasions. Calcium levels west of the Cascades are generally quite low, below the levels the research indicates can sustain mussels. On the basin's east side, calcium levels are a tad higher, "but still not very high," Heimowitz said.

Yet another study, which takes into account water temperatures and other variables, calls the Columbia basin at high risk for a zebra or quagga invasion.

"In my mind the jury's still out," Heimowitz said. The Colorado River basin, as an example, was written off as a mussel host because of environmental conditions, yet an invasion transpired.

"The bottom line is that most invasive species are invasive because they are adaptable," Heimowitz said.