Decontamination Demystified

This year the legislature passed and Governor Dayton signed innovative legislation to protect our lakes sending $10 million in Aquatic Invasive Species (AIS) prevention aid to counties. This annual appropriation will be divvied between the counties based on the number of public boat launches combined with the number of watercraft trailer parking spaces in each county. The first instalment arrived July 20th.  This remarkable innovation puts funding at the source, where it is most needed and can do the most good. And that is the problem.

“The counties are required by statute to use this money to prevent the spread of aquatic invasive species,” said Jeff Forester, Executive Director of Minnesota Lakes and Rivers Advocates. “But many have little or no experience in this area. The models put forth by the MN DNR and MN Sea Grant focus on education and personal responsibility, but have not yet been able to provide the tools that have solved the problem of spread.” Some local governments have partnered with Lake Associations or County Coalition of Lakes Associations to further their programs.  One is Becker County.  On September 30, Becker County brought in Jim Foust, a national AIS leader based in Utah, who introduced a state of the art zebra mussel decontamination unit - the first of its kind in the state, and provided Becker County AIS managers with 20 hours of training in inspection, local AIS program management, and proper decontamination methods.

Said Jeff Forester, “Minnesota has 13,000 lakes, a daunting number when considering inspection programs. But Minnesota also has a unique lake culture fueled by hundreds of active lake associations.  The funding provided by the Legislature and Governor Dayton last year is leveraging this potential and taking Minnesota far down the road towards a comprehensive statewide strategy to stop the spread of aquatic invasive species.”

Luckily Minnesota’s counties do not have to reinvent the wheel. Said Forester, “Other countries and states have been implementing local AIS programs for years.”

Perhaps the father of local AIS prevention efforts is Wen Baldwin, from Lake Mead, Nevada. In 1997 Baldwin was the President of the Lake Mead Boat Owners Association. He saw a presentation on zebra mussels put on by Lake Powell and became concerned. Baldwin contacted various agencies for information and help in setting up a program to protect Mead.

Wen developed educational materials, and pulled information and protocols from other groups in the United States that were doing similar work. Baldwin and others developed a Five Point plan for AIS management:

  1. Inspection of all boats before entering a lake or river.
  2. Mussel Decontamination of all watercraft and equipment leaving infested waters, and contaminated boats entering any water body.
  3. Enforcement of strong deterrent laws,
  4. Education and outreach for public awareness,
  5. Research in biology, social science, economics and limnology to understand the invasive species, their impacts on water bodies, the vectors of spread, and human interaction.

Baldwin was able to leverage local activists and agency resources to get inspectors at the Lake Mead Boat ramps, but ran into a major stumbling block when he looked for a way to decontaminate watercraft infested with Dreissenid mussels (including zebra and their more destructive cousin quagga mussels).  On cool humid days adult zebra mussels live for a month out of water. Possible methods included freezing, chemical treatment, physical removal, and thermal water treatment. For ecological reasons and cost effectiveness thermal water treatment seemed best.  But research about the temperature and exposure times required to kill zebra and quagga mussels was not available, and there was no manufacturer seeking to address this issue. Also, because larval mussels (veligers) are microscopic and could survive in residual water, it became clear to Baldwin that they must be able to treat all areas of a boat, even boats with complex water systems like houseboats, ballast water boats and cabin cruisers.

Baldwin ran into yet another stumbling block when he determined that water hot enough to kill adult Dreissenid mussels, 140 degrees for 10 seconds, was also hot enough to damage some of the seals and ballast tanks in some boats. When Baldwin looked at using a high pressure-hot water system with a thermostat he quickly realized that a thermostat was unable to measure and regulate the temperature of water as it hit the surface being treated. Variables like elevation above sea level, relative humidity, outside air temperature and differences in the conductivity of materials being treated added more complexity.

Then there is the complexity added by the many varieties of aquatic invasive species currently threatening Minnesota’s lakes and rivers.

Dr. Peter Sorensen at the University of Minnesota (Founder of MN Aquatic Invasive Species Research Center), suggested that the term decontamination “be used very carefully and be explicitly defined in highly context-specific manners.”  In particular, he pointed out “that folks rarely define the ‘contaminants’ of interest and that waterbodies in our state are in fact threatened by many AIS including quagga mussels, zooplankton (spiny waterflea), plants, and microbes (VHS) -- and treatments which  kill one species will not consistently kill all of the others -- so we run the risk of letting one through while preventing others.”

For example, spiny waterflea eggs and Eurasian milfoil are not killed by the conditions that kill zebra mussel (140F for a full 10 sec). But Eurasian milfoil and spiny waterflea eggs, are extremely susceptible to drying or detachment.  Dr. Sorensen suggests that folks specify exactly which AIS they are treating for and why (for example use the term ‘Dreissenid mussel decontamination’ not just ‘decontamination’), and be aware of the limitations of any AIS decontamination strategy.  Nevertheless, Sorensen points out that regardless of the approach taken, it is absolutely critical to have the best possible equipment whose operational characteristics are precisely controlled and well understood as they impact the targeted AIS.  “Even small deviations in treatment protocol or ignorance about other species needing different conditions can result in few percent survival which can be disastrous. There is unfortunately no room for machine or operator error, imprecision, or ignorance of broader threats.”

Simply put, true decontamination for AIS must involve a variety of strategies, including drying water related equipment long enough to kill some AIS, removing all plant and animals, and thermal hot water decontamination with each strategy addressing a different species. This is the spirit behind the Clean, Drain, Dry message.

“There is a big difference between hot water pressure washers (or car washes) and a zebra mussel decontamination unit,” said Baldwin. High pressure hot water sprayers may be able to remove easily accessible mussels, flush out easily reached compartments and bilges, but can and do leave many areas on more complex boats untreated.

Another major concern with decontamination is the disposal of waste water. When spraying every nook and crany, not only are some organisms removed that may be still alive, like spiny waterflea eggs, but hot water also removes many chemical contaminants. MN DNR Inspection Supervisor Evan Freeman said, “We swap out our water every two weeks unless the water gets really bad sooner than that.  The recycled water is disposed of at locations near where they are stored that have the ability to ground filter and are contained so any potential runoff cannot make contact with local riparian areas.” Said Phil Munson at the MN Pollution Control Agency, (This method of wastewater disposal) Probably is not a problem,” but noted that, “The best option for discharge would be to put it (decontamination wastewater) in a sanitary sewer or to treat it.”

Baldwin started looking for a business partner as there was no off the shelf unit that he could find which would 1) Kill and remove all Dreissenid mussels from any watercraft, 2) Was controllable so that operators could decontaminate without damaging the watercraft, 3) Could process the wastewater produced to Federal Clean Water Act standards.

Baldwin eventually found Jim Foust at a company called Hydro Engineering, which made decontamination equipment for military applications - think mustard gas on a B-52 bomber. Foust, Baldwin quickly learned, was an avid boater.  Foust said, “Wen called me about 2003, introduced himself and started telling me about mussels.  I had absolutely no idea about the issue….”

Working together Baldwin and Foust converted and adapted the Hydro Engineering’s military equipment for watercraft. “We dedicated a lot of time and effort to temperature regulation, attachments and after sale support.” Working with Hydro engineering, Baldwin developed a training program to teach operators how to use decontamination equipment and set up AIS programs that had Dreissenid mussel decontamination as an element in wider protocols to catch other AIS. The AIS Academy at Lake Mead was born. It is widely regarded and remains the basis for the Marine Pacific States Fishery Commission inspection/decontamination certification used by states across the West.

Said Baldwin, “Today, using this system, I am confident that I can decontaminate any watercraft without damaging it or the environment. That was not the case when I started over twenty years ago.”

Said Foust, “A large part of our technological expertise is wastewater management and hence our … closed-loop processing using our Hydrokleen contaminant removal.  Wastewater can be collected from a mobile unit and managed properly..., negligent disposal of wastewater from decontamination can not only pollute but can cause an infestation elsewhere.“

Unfortunately, before Wen Baldwin could get the new decontamination units from Hydro Engineering in place to protect Lake Mead a colony of quagga mussels was discovered. Three months later Baldwin installed two decontamination units from Hydro Engineering at Lake Mead; one at Callville Bay and another at Hemenway Bay. “Our focus now is on decontaminating boats leaving Meade to protect other waters,” said Baldwin. While Lake Mead is infested with quagga mussels, they do not yet have zebra mussels. 

The man who started the modern method of using inspection/decontamination to stop the spread of AIS lost his race against the clock. But in Minnesota less than 200 of our estimated 13,000 water bodies are infested with ZM. The rate of spread is accelerating however. Despite decades of education and outreach, the MN DNR is still reporting an AIS violation rate of 26%.  Increasing the quality of inspection and ZM decontamination programs would surely help as would decreasing the amount of equipment exchange between high risk bodies of water.

Next year, with the $10 million increase in local AIS funding there is hope. Other counties will hopefully follow Becker County in both their training and use of cutting edge technology.

“Minnesota is well positioned for success,” said Jeff Forester.  “We have the experience of those who have been doing this work longer than us, we have a reliable and ongoing source of funding, we have remarkable energy and commitment from volunteers at the local lake associations, we have a research center at the University of Minnesota.  And now Becker County is bringing in the highest performance decontamination equipment and training available.”

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