The Zebra Mussel

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The ZebraMussel

• What A
• Homeowner
• Needs to Know

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June 1988 - Lake St. Clair
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Zebra Mussel U.S. Range
December 1989
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Zebra Mussel U.S. Range
December 1990
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Zebra Mussel U.S. Range
December 1992
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Zebra Mussel U.S. Range
December 1999
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Potential Zebra Mussel U.S. Range
December 2020?
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Recreational Boating...
The most likely inland spread vector
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Water Treatment Plant Ozone Contact
Chamber (Monroe, MI, WTP)
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Circulating Water Pump Bell Housing (Detroit
Edison, Monroe, MI)
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But Huge pipes arent the only ones at
risk. Zebra mussels are already clogging
thousands of small intakes, as well.
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Why Havent We Heard of This Problem Before Now?

• Early colonization is spotty with low mussel
  densities

• Densities of mussel veligers in water column are
  low
• Power plants and drinking water facilities have
  huge water demands and draw in millions of
  veligers
• Power plants and water treatment plants pump
  water for long periods of time, sucking in more
  veligers
• Many residential systems may face imminent
  failure but havent been clogged yet
• Many people affected by power plant or water
  treat-ment plant shutdowns clogged residential
  pipes impact fewer

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Watch carefully Zebra Mussels come in ALL
sizes and coloration patterns
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Water Intakes Excellent Zebra Mussel Habitat

• Continuous source of food and oxygen

• Continuous removal of wastes
• Protection from predation
• Protection from severe weather

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Byssal Threads..
The zebra mussel's secret weapon
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Zebra mussels can completely plug small water
intake pipes in very little time
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Zebra Mussels in Residential Water Systems
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Zebra Mussel Fouling ofResidential Water Systems

• Intake pipe

• Strainer
• Foot valve
• Pump
• Pipe itself
• Storage/pressure tank
• Distribution pipes

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Zebra Mussel Impacts onResidential Water Systems

• Loss of pumping efficiency

• Obstruction of foot valve
• Clogging of intake pipe
• Wear tear on pump
• Clogging of distribution pipes
• Taste odor problems
• Increased corrosion

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• Are mussels growing around or within mouth of
  pipe?

• Is there a noticeable decrease in water volume
  and pressure?
• Are there unpleasant tastes and odors in the
  water?

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Factors Influencing Rate of Zebra Mussel Fouling
of Residential Water Systems

• Water chemistry of the waterbody

• Extent of zebra mussel colonization near mouth of
  intake
• Position of the mouth of intake in the water
• Composition of the intake pipe
• Volume and velocity of water flowing through the
  pipe

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Reducing the Risk of Zebra Mussel Fouling
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When to Implement Zebra Mussel Control in
Residential Water Systems

• Continually (no mussels tolerated ever)

• Periodically (some mussel growth is allowed,
  followed by removal of the mussels)

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Residential Water Systems
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Residential Water Systems
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Residential Water Systems

• Most difficult to protect
• Often least costly to repair

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Residential Water Systems

• Easiest to protect
• Most costly to repair

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Protecting the Onshore Component of Residential
Water Systems
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Onshore ComponentControl Alternatives

• Replaceable or cleanable in-line filter

• Chlorine injection at pump or pressure tank
• Combination of filtration chlorination

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In-Line Filtration

• 40 micron maximum

• Removes all life stages

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Whole HouseIn-Line Filters

• Single media filamentous angel hair (25 - 50 ?)

• Ceramic filters (50 ?)
• Spun cellulose or ceramic fiber cartridges (lt10
  ?)
• Dual media filters
• Fiber media around activated charcoal core (lt10
  ?)
• Removes many flavors odors
• Back-flushable filters or microstrainers (lt10 ?)

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Whole HouseIn-Line Filters

• Least expensive

• Require periodic filter cartridge replacement
• Increased backpressure can force live larvae
  through filter
• Back-flushable filters clean filter media by
  reversing flow of water and flushing out filter
  media

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Whole HouseIn-Line Filters
Cleaning / replacement timing depends upon

• Amount of silt, algae, zebra mussel veligers, and
  other particles drawn into system
• Intakes location in the waterbody
• Time of year

• Spring summer silt loads
• Storm silt loads
• Summer algal growth

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Whole HouseIn-Line Filters

• Do not allow material trapped within filter to
  bypass the filter during cleaning / replacement

• Cleaning / replacement of clogged filters is an
  on-going cost time commitment
• Automatic back-flushable filters can eliminate
  one of the maintenance tasks

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In-Line Chlorination

• Kills all life stages
• Kills many other pathogens
• Remove taste with carbon filter

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Filter-Chlorinator Combo

• Healthier water
• Kills or removes all mussels

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Hand-Driven Shore Well
Pumphouse
Driven pipe with well point
Infiltration from waterbody
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"High Tech" Shore Well
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Shore Well with Infiltration Channel
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Drilled Wells
The ultimate onshore preventive measure

• May not be viable alternative where
• No available aquifer
• Sulfurous water
• Salty water
• Polluted ground water

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Offshore Strainers
Use of screens or strainers at intake end of pipe

• Effectiveness depends upon
• Mesh size of screen
• Size of mussels being drawn into pipe
• Common mesh on small intake (1/4 - 1/2 inch)
  keeps out leaves but not zebra mussel veligers
  (as small as 70 ? 3/1000 inch)
• Simple screens are ineffective as a zebra mussel
  control method

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Offshore Strainers
Effectiveness can be increased by reducing mesh
size

• Too small openings can clog quickly with silt,
  algae, and debris
• Screens can become fouled

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Offshore Filtration

• Constructed alternatives
• Infiltration galleries
• Raised fill beds

• Manufactured alternatives
• Prefabricated sand filters
• Ceramic filters
• Cartridge filters

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Infiltration Gallery
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Raised Fill Bed
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Backflushing Offshore Filters

• Infiltration galleries and raised fill beds will
  eventually clog with fine particles

• Backflush by pumping water from shore through
  pipe system to flush out fine particles
• Sand beds can become compacted over time

• Cracks can form in sand
• Zebra mussel veligers can be drawn into pipe
• Backflushing fluffs sand up, prevents cracks

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Prefabricated Sand Filter
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Manufactured Offshore Filters
Homeowners should investigate the product

• When, where, how long, under what conditions have
  filters been field tested?
• Names of clients with filters in water for
  reasonable length of time
• What happens if system clogs prematurely?
• Is automatic backwashing available as option?

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Offshore Filters andWater Potability
Offshore sand filtration can remove zebra mussels
and other large particles

• By itself, offshore filtration is not intended to
  provide potable (drinkable) water
• Additional treatment by chlorination or
  ultraviolet light needed to kill bacteria
• Consult county Cooperative Extension Service or
  health department about drinking water standards

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Environmental Impacts ofConstructed Offshore
Filters

• Turbidity during excavation and backfilling
  impacts local water quality temporarily

• Use trenching equipment rather than backhoes
• Use silt screens around excavation site

• Disturbance of natural lake or river bottom
  habitat

• New habitat provided by stone cover material
• Prefabricated sand filter minimizes habitat
  loss with smaller disturbance
  footprint

• Permanent change in bottom habitat type from
  natural to human-influenced substrate

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Offshore Ceramic andCartridge Filters

• Abrasive ceramic filter media removes or destroys
  mussel veligers
• Cartridge filters trap particles, including zebra
  mussel veligers

• Porosity should be small enough so that no mussel
  life stages will pass live into intake pipe
• Available with manual or automatic backwash
• Should ask how often the filter media needs to be
  replaced or cleaned

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Nonfouling Pipe Materials
Copper or galvanized intake pipes

• Discourage zebra mussel attachment
• Lose effectiveness as they corrode or oxidize
• Should be augmented by other methods

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Periodic Cleaning ofOffshore Component

• Allows some clogging by mussels, followed by
  periodic maintenance

• Cleaning
• Mechanical
• Thermal
• Pipe replacement

• Protect onshore component with its own system
• Install Y connection cleanout at shore end of
  pipe to facilitate cleaning

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Periodic Cleaning ofOffshore Component
Plumbers snake for short pipes with easy access

• Loosened mussels must be removed by
• Pumping through a strainer at the pump
• Opening foot valve and backflushing
• Not possible in pipes with

• Tight bends
• Check valves
• Radical diameter changes

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Oxygen Deprivation

• Zebra mussels breathe oxygen as water passes
  over their gills

• Seal both ends of pipe long enough for water to
  lose all of its oxygen
• Oxygen demand greatest in warm water
• Oxygen deprivation most effective in summer
• 2 to 3 days anaerobic water at 74º F 100 kill
• Most suited to weekend cottages that routinely
  have water system shutdowns
• Year-round homes will need second intake

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Removable Intake Pipes
Weekend cottage low water demand not for
drinking

• Single short flexible plastic pipe directly on
  lakebed
• Pull from water - leave on shore - dry in sun
• Dead mussels snaked from pipe
• Replace into water next weekend
• Several times a season based on speed of fouling
• Dual short flexible plastic pipes
• Pull one-at-a-time from water, leave on shore,
  dry in sun, and clean
• Pumping continues through second pipe
• Onshore piping protected by onshore filtration

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Thermal Treatment
Periodic flushing with hot water

• 90º F for about 1 hour 100 kill
• gt 130º F immediate kill
• Foot valve must be open to allow flow of hot
  water
• Cold lake water is heat sink - need enough hot
  water to fill pipe and keep hot long
  enough for kill

• Hot water discharge negative environmental
  impact
• Dead mussels must be removed by backflushing
• Portable steam generator from shore end of pipe
• Live steam instant kill
• Less hot water discharge

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Chemical Treatment

• No environmentally sound chemical treatment
  system for offshore part of residential water
  intakes

• Never pour or backwash chemicals down intakes
• Environmentally harmful effects on fish,
  zooplankton, and bottom-dwelling invertebrates
• Might be harmful to human health
• Could be illegal if discharged into surface
  waters
• Not effective in killing zebra mussels due to
  short contact time afforded in a residential
  intake pipe

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Deeper Intakes

• Deep water intake might minimize colonization

• Water too cold
• Insufficient food supply
• Zebra mussels survive near-freezing Great Lakes
  winters with little damage below ice scour zone
• Veligers found down to about 200 feet
• Cost of very deep intakes prohibitively expensive
• If waters below thermocline become oxygen
  depleted, sub-thermocline intakes could minimize
  colonization

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Multi-Residence Systems
Most control alternatives can be scaled up to
meet needs of multiple residences

• Cost per residence could be lower than for single
  residence systems
• Multi-residence systems help eliminate
  proliferation of smaller, less efficient
  individual systems
• Might be more environmentally sound

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Written and Produced By Charles R. ONeill,
Jr. New York Sea Grant 2001