Below (down the right side) are some pictures that we took of a foot valve intake for a property in Isle LaMotte. The customer's water intake had stopped, and consequently burned out their water pump.
When inspecting the foot valve in the lake, we found it to be full of Zebra Mussels; blocking the foot valve's mechanism from working. Consequently the Zebra Mussels also invaded the water line up to the house. The first photo shows the inside of the foot valve cover (the external zebra mussels had already been scrapped off) and the zebra mussels that had made it inside as small creatures (villagers) and then grew to adulthood. The second and third photos show the zebra mussels interfering with the mechanism (that the cover was protecting), causing failure.
Carl Penske has custom designed a Zebra Mussel filter which is attached to the end of the water line in the lake. Once attached, it is effective in eliminating the Zebra Mussel infestation into water lines; as long as the filter is maintained on a yearly or biyearly schedule based on its location and water depth.
The photo below this comment is of the Grand Isle Fire District 4 water intake. It is just another example of the Zebra Mussel progression to complete coverage of anything (with the exception of copper) in our lake.
We design custom Zebra Mussel Filters; providing installation, follow up service & inspections.
Here is an exert from the Vermont Watershed Management Division (http://www.watershedmanagement.vt.gov/lakes/htm/ans/lp_zebra.htm)
The zebra mussel is a small freshwater mollusk, native to the Caspian and Black sea region of Eurasia. Adult zebra mussels attach themselves to firm surfaces with strong hair-like fibers called byssal threads. Each female zebra mussel can lay up to one million eggs during the summer months when water temperatures rise above 50°F. The fertilized eggs hatch into microscopic juveniles called veligers, which can travel great distances following water currents or when transported on boats and trailers. These methods of spread lead to rapid infestation of new waterbodies. Once settled on a firm surface, the veligers grow rapidly into "D" shaped, one inch size adult mussels. Colonies of adults can attain densities of up to 700,000 individuals per square meter. Zebra mussels generally live for two years in North American waters, but can survive for as long as 4-5 years.
Zebra Mussel Filters