Springer, Steve. 1998. The "Mechanical" Filtration Option for Zebra Mussel Elimination. Amiad Water Systems Technologies

The control of zebra mussels and other mollusks with mechanical filtration has long been debated as a systematic and efficient means to provide a 100% barrier for all "viable" life forms of this, and other "aquacritters". Now, however, based on independent testing and actual filter system installations, this mechanical alternative for preventing their intrusion into piping and water systems has been proven to be reliable, economical and ecological friendly. Further, it is now substantiated and documented that a specially-fabricated weave of 40-micron "absolute" stainless steel screen will stop all viable life forms of mollusks. However, the success of stopping the mollusk provides only half the process. Once these organisms have been collected in this 40-micron weave, they must be removed and discharged as easily as they were collected. The most significant advantage to the mechanical filtration option is ecological. With mechanical filtration, there are NO chemicals or "special" handling of the wastewater. Without the use of chemicals the water does not have to be "de-chemicalized" or sent to sewer. With mechanical filtration, both the "waste" water and the system water can be discharged or used without any potential impact on the environment or their ecosystem(s).

The other significant advantage is that of cost. Although mechanical filtration can be a significant up-front capital expense, the effect on future annual maintenance budgets is very minimal. Unlike that of chemicals that require ongoing expenditures in purchasing costs, storage costs, and elimination costs, "screen" mechanical filtration has no medium to replace each year and very little annual service maintenance.

For reference purposes, a 5000 GPM system, requiring 40-micron absolute filtration, will have an average up-front cost of about $40 to $45 per gallon of filtered water. This of course is very subjective due to the variance in factors not addressed by filtration alone; i.e., control systems, screen micron selection, variations in water quality, and most importantly system flow rate. (Although 40-micron absolute is necessary for 100% removal of all life forms, 100% removal may not be a requirement for every system and this choice can have a significant impact on cost.)

For over 30 years, Amiad Filtration Systems has been providing innovative and reliable filtration systems. During that time Amiad was able to develop and perfect the hydraulic and mechanical (symbiotic) relationship between screen filtration and screen cleaning technology. Over the past three years, Amiad has proven that their "technology" in filtration systems does in fact provide the mechanical protection required to prevent zebra mussel intrusion into waterways and piping systems. Amiad's patented automated self-cleaning screen filters provide both the mechanical filtration requirement of 40-micron absolute and a "scanning" cleaning method that efficiently and effectively cleans 100% of the screen surface.

Independent testing done by Acres International for the State of Michigan substantiated this in 1993. These tests demonstrated not only the integrity of the screen but, the screen cleaning system. A filter system (three filters with a combined filtration area of 4560 sq/in.) was then installed at the Mud Creek Irrigation District for the control of zebra mussels for irrigation water. The filter system was designed to handle a flow rate of approximately 7000 GPM and provide irrigation water to a ditch system being pumped from Saginaw Bay - Lake Huron. The system saw its first successful "full" season of operation in 1997 and has been monitored under the guidelines provided by Acres International and the State of Michigan.

Further, in 1996 Amiad provided an even more unique zebra mussel filtration system to the State of Vermont for the State fish hatchery. This system was unique in that it not only required 40-micron absolute protection, it had to provide protection from two independent gravity water sources through the same filtration system being supplied from low pressure supply lines. This required a very sophisticated control and pumping system that interfaced with the filters to supply "mollusk free" water to the hatchery. This system just finished its first full season of successful operation.
Mechanical filtration is the effective option to stop zebra mussels!

Contact: Steve Springer, Amiad Water Systems Technologies, P.O Box 5547, Oxnard, CA 93030
Keywords: Zebra_mussel, Physical_control, Filters
Product Type: Publication, Proceedings
User Type: Industrial_and_Municipal