About Our Boat Wash

Clean Boats, Clean Waters

On June 8, 2017, Act 67 became law requiring any person transporting a vessel to or from a body of water to visually inspect the vessel, the transport vehicle, and other equipment used and remove any aquatic plants, aquatic plant parts, and other aquatic invasive species. The law also requires boat operators to remove drain plugs and all devices designed to control the drainage of water from a vessel while transporting it.

Boat inspection and decontamination (boat wash) are now mandatory for all watercraft at all authorized aquatic nuisance species inspection stations if:

  • the inspection station is maintained where the vessel is entering or leaving the water
  • the inspection station is open
  • an individual operating the inspection station identifies the vessel for decontamination.  

A person who violates this law may be subject to a penalty of up to $1,000 per violation. To read a summary fact sheet on Act 67 and the update to aquatic invasive species transport law click here.

The Shadow Lake Boat Wash, established in 2003, is the first and only hot water (140°F ) high-pressure watercraft decontamination station operating in Vermont as of 2015. The Shadow Lake Association in partnership with the Town of Glover has operated the Boat Wash throughout each summer season. Of the 27 locations around the State where watercraft inspections were taking place in 2015, Shadow was the only waterbody location with Greeter staff washing boats!

One of our Greeter's washing a boat previously from nearby Crystal Lake confirmed to have a Eurasian Watermilfoil infestation.

One of our dedicated Greeter’s working to hot water power wash a boat after inspection before launching into Shadow Lake.

Our program began as a proactive effort to prevent the introduction of all aquatic invasive species (AIS) from entering the lake. Hot water, high pressure decontamination stations have been shown to be the most effective in removing and/or killing a host of AIS. Basic decontamination protocol entails a power washing treatment of all high risk areas of a watercraft with hot water for a minimum of ten seconds. The temperature and methods used are effective against a host of different species, but are safe for watercraft hulls, motors, pumps, and other equipment when used properly. Our Boat Wash Coordinator, and many SLA Board of Directors along with our Greeter staff attend annual training workshops provided by the experts from the Vermont Department of Environmental Conservation.

Our friendly staff of Greeters are stewards of the lake who welcome and educate visiting lake-users about the harmful effects of AIS and the steps that can be taken to prevent the spread while offering assistance with courtesy watercraft inspections and free boat washes to stop invasive species introductions. Depending on the size of the watercraft, typically the inspection and decontamination process takes 3-10 minutes, with little inconvenience to boaters as they launch or retrieve their watercraft.

c. J. Dunbar

The assembly of our popular boat wash station upcycles an old horse trailer rebuilt to house our hot water tank.  The trailer also serves as a cozy shelter for our Greeter’s while on duty, complete with a desk top, chairs, data collection materials and educational literature for lake-users on the importance of AIS spread prevention to help protect this lake and all other waterbodies.

c.. J. Dunbar

The Shadow Lake Association strongly encourages the washing of all watercraft (including kayaks, canoes, paddle boards and other non-motorized boats) before entering and upon exiting Shadow Lake to reduce the risk of transporting Eurasion watermilfoil (Myriophyllum spicatum) and all other aquatic invasive species.

Prevention is the Key!

Preventing the spread of aquatic nuisance species through boat washing and vigilant lake monitoring for early detection is the most environmentally sound and cost-effective method for battling aquatic hitchhikers. The most important action you can take to limit the spread of non-native aquatic plants is to remove all vegetation and animals from your watercraft and any water-related equipment before you move it from one body of water to another. If these invading species become established, they can be impossible to contain and control.


Please don’t be a carrier of aquatic invasive species!

Human recreational activities typically account for the majority of non-native aquatic plant and animal spread between lakes.  To prevent the spread of aquatic invasive species, before and after boating, (the primary vector) it is absolutely vital to practice  ‘Clean, Drain & Dry’ a simple mantra adopted by many States to help remember to carefully inspect for aquatic invaders hitchhiking on your watercraft, trailer, equipment and related gear every time you take them out of the water.


  • Clean off all mud, plant fragments, attached animals and  place removed material in a trash receptacle. Wash watercraft, trailer and equipment to decontaminate;
  • Drain watercraft and accessory equipment away from the water; and
  • Dry anything that comes in contact with the water.  A minimum of 5-7 days of drying time is recommended in the summer before entering another waterbody.

This 10 minute video shows paddlers of non-motorized watercraft how to prevent the spread of aquatic invasives by utilizing the simple three step method: Clean-Drain-Dry.

– Drying times vary based on temperature, humidity, and material.  If your boating and fishing equipment cannot be properly dried before its use in another body of water, it must be disinfected.  See more information on disinfecting.

In September 2011, a pioneering infestation of Eurasian watermilfoil was confirmed growing in a small cove of Shadow Lake and in all likelihood would have been transported to the lake much earlier if our Boat Wash had not been in use. To avoid the risk of possibly spreading any Milfoil from this lake to any other water bodies, we encourage all watercraft to be washed upon exiting the lake.


Because Shadow Lake may have snorkelers and SCUBA divers present, our Greeters also remind boaters of the Vermont law;

imageNo propellers can be engaged within 200 feet of a displayed diver down flag. For human safety, when you see this flag displayed, slow down and turn away, divers may be at the lake surface or underwater.


Greeters also warn boaters to stay well away from any orange buoys that may be anchored at various spots around Shadow Lake.  Orange buoys indicate a critical control site of Milfoil for our divers and snorkelers to manage and all other human activity to not disturb.



The Shadow Lake Association, the community and the users of Shadow Lake must continue to work together to prevent the thick growth and spread of Milfoil as shown in the picture below of an infested waterbody.



Although some invasive species such as Eurasian watermilfoil can be readily visible to the human eye, many other aquatic invasive animals, such as Zebra mussels (Dreissena polymorpha), have life stages too difficult to see with the unaided eye and can survive in tiny amounts of moisture for several days.  On smooth surfaces young Zebra mussel settlers feel like sandpaper to the touch.  Pressure washing will dislodge microscopic eggs and settlers and 140°F hot water will kill them as well as Spiny water flea (Bythotrephes cederstroemi) and Eurasian watermilfoil.



To read more about Spiney water flea: 

see: Spiny water flea or US Government Spiney water flea Fact Sheet




Zebra mussel with tiny byssal thread secretions to anchor to a variety of surfaces

Zebra mussel with tiny byssal thread secretions to anchor to a variety of surfaces


To read more about Zebra mussels:

see: US Government Zebra Mussel Fact Sheet

Also: to see many other Invasive Aquatic Species go to the Vermont Watershed Management Divisions  a gallery of Invasive Aquatic Species



This video, although made in New York, is applicable to Vermont and contains valuable information.

Do your part to keep our waters clean, healthy and enjoyable!

Eurasian watermilfoil

Eurasian watermilfoil (Myriophyllum spicatum L.) is a non-native invasive submerged aquatic perennial plant that propagates through root division, stem fragmentation, and seeds.  Milfoil is known for its rapid growth and reproduction and ability to spread beyond control.  Milfoil often invades aquatic ecosystems in North America via plant fragment transport from infested lakes to uninfested water bodies by watercraft, boat trailers and related equipment.



Milfoil is commonly found in shallow bays and along the shoreline. The submersed plants typically grow in water as deep as 20 feet and has a theoretical depth maximum of 33 feet in exceptionally clear water.



Eurasian watermilfoil is an extremely hardy and adaptable plant, able to tolerate and even thrive in a variety of environmental conditions and is extremely difficult to control after it has been introduced to a waterbody due to its effective means of spreading through stem fragmentation and root stolons.  Its early seasonal growth and spread out-competes and displaces the existing beneficial native aquatic plant population for light and sediment nutrients.  Milfoil roots grow readily in various substrates. Stems emerge from the root crowns each year to rapidly grow to form dense beds. The number of stems per plant increases as the plant ages.

Photo credit oneidacountyais.org

The stems stretch toward the surface and then branch profusely to form thick floating canopies that shade out native vegetation, interfere with recreation and provide a perfect breeding habitat for mosquito larvae.


Local spread is vigorous in mid summer.  The colony expands by lateral root stolons to form new plants and the dispersal of self-generated fragments.

The Trouble With Fragments

  • Milfoil stems automatically separate from the parent plant and disperse into the water.
  • The abscising stem fragments often develop roots at the nodes before separation and are capable of forming a completely new plant.
  • The fragments break off, sink and root into the bottom or can remain buoyant and drift in the current transported over long distances to eventually settle and establish new colonies.
  • Fragments not only survive but increase in length and biomass while suspended in the water column for long periods of time.
  • The fragments facilitate stored carbohydrates as a reserve for overwintering or regrowth after dormant periods or plant damage.
  • As Milfoil stems elongate toward the surface, they twist, become weakened and brittle and are easily subject to breakage resulting in more fragments.
  • Fragments are also produced by water turbulence from wind and wave action as well as boating disturbance and other human recreational activities.
  • Science has shown if you are able to reduce the number of fragments being produced by reducing the biomass than you can reduce and even stop the spread of Milfoil.

Photo credit nwcb.wa.gov

By mid to late summer flowering spikes typically emerge from the water but not all Milfoil colonies produce flowers. The seeds are not considered important to its propagation.  Most regeneration and dispersal of Eurasian watermilfoil within lakes occurs primarily by the lateral stolon growth and secondarily by fragmentation.  Certain Milfoils are also able to hybridize with other, closely related, Milfoil species.

During the fall, some plants die back to the root crowns.  The decomposition of dying plant mass negatively increases the phosphorous and nitrogen in the water and decreases the dissolved oxygen necessary to support the ecosystem. Phosphorous is the nutrient that poses the greatest threat to pristine water.  Some Milfoil plants can adapt to surviving under the winter ice intact.  In the spring, as the water begins to warm, the vigorous growth cycle and spread begins again.

Eurasian watermilfoil’s aggressive growth of dense weed beds is a significant threat to all our lakes and ponds.  A well established Milfoil infestation will seriously alter a lake’s natural environment; 

  • Milfoil degrades lake water quality;
  • It reduces biodiversity by displacing desirable native species;
  • Reduces aquatic invertebrate community which effects the entire food chain;
  • Reduces the fisheries population;
  • Chokes-out to eliminate the beneficial native plants and fish spawning beds are lost;
  • Accelerates oxygen loss in the water;
  • Decreases the PH level;
  • Greatly impedes recreational use;
  • Reduces aesthetic values;
  • Soon real estate values decline.

Two tiny viable fragments of Milfoil complete with attached roots, each capable of beginning a new infestation.  ~ photo credit, C. Cano

Due to the insidious nature of this highly invasive and aggressive species, just one small piece of Milfoil is capable of starting a new population in a different body of water.  This is why Milfoil can be so easily transported from lake to lake when attached on any type of watercraft, trailer or fishing gear. Any equipment used on or in the water can collect and spread AIS.

Our Association has posted this advisory sign to alert boaters to take precautionary measures when our boat wash is not in operation.

Our Association’s proactive approach of posting this advisory sign to alert boaters to take precautionary measures when our boat wash is not in operation will hopefully help to stop the spread of milfoil to any other water bodies.

Once Eurasian Watermilfoil has infested a lake it is extremely difficult if not impossible to eradicate.  Lake managers can often only seek to control the spread by integrating the most effective, economically feasible and environmentally sound best management practices available.  If Milfoil becomes well established and gains dominance over the shoreline area, the probability for eradication decreases drastically.  Once the entire littoral zone (where sunlight penetrates to the lake bottom) becomes a monoculture stand of Milfoil, most functional aspects of this highly productive part of the lake are lost!  Taking rapid and early action when a milfoil infestation is first detected in a water body will minimize environmental impacts to the ecosystem and lessen the economic impacts to the community.

Achieving control is expensive and takes a number of years, requiring a sustained concerted effort on the part of the local government and lake group.

Programs aimed at preventing the spread or introduction of invasive species into Vermont are the best and least costly means of protection available. The Shadow Lake Association’s Milfoil Committee’s early detection efforts includes lake mapping and conducting weekly underwater inspections of the shoreline to monitor for the presence of Milfoil and other aquatic invasives throughout the summer season.  We typically conduct two, back to back, lake-wide surveys, June through September, with our team of boat surface support to assist our professional divers and volunteer trained snorkelers.  Our Boat Wash program is another example of a working method to help prevent aquatic invasive species from infesting this lake.

This video, although made in Michigan, is applicable to Vermont and contains valuable information.

Identifying Eurasian Milfoil


Eurasian watermilfoil is recognized primarily by its whorls of four feather-like leaves around the stems. Each leaf is finely divided into paired leaflets, typically 12 to 21 pairs per leaf. Each individual stem branches several times as it nears the water surface, creating a dense floating mat over the surface of the lake. The tops of the stems and leaves of milfoil plants, including the small flower spikes rising above the surface, often turn reddish in color.


Click the image to see a larger view

For more information on Eurasian watermilfoil and a gallery of other invasive species see: VTDEC

You Can Help

Here are several ways in which you can help to support the boat wash and lake monitoring:

  • One of the most important steps you can take to help stop the spread of aquatic invasive species is to become educated about the subject and help educate other lake-users as well. Get involved in local programs that help to protect our waters.  Public participation is essential to the success of AIS spread prevention efforts.
  • Join our membership! Annual dues are only $25.00 per household. Membership is your personal statement that you care about supporting the Association’s mission to protect and preserve Shadow Lake and the surrounding watershed for the mutual benefit of all.  
  • Lend your expertise! Join the Board of Directors see page or simply volunteer, depending on your interests, to work on your choice of any of our committees or projects helping to protect the lake. Contact any Director and we will coordinate a way that is comfortable for you to lend a helping hand.
  • The Boat Wash is our lake’s first line of defense against AIS! Please consider becoming a ‘volunteer’ Boat Wash Greeter for a few hours during those critical times that can not be covered by staff. A Director will be happy to assist you with the necessary training and orientation.
  • Get involved! Learn to recognize aquatic invasive species. Participate in the Vermont Invasive Patrollers (VIPs) program see our page or simply volunteer on your own to help search for Milfoil and other non-native invasive species in the lake from your kayaks or canoes and even during your swim.  If you like, you can ‘adopt a section of shoreline’ to regularly watch over.  Just keep a log or mark your calendar with your time spent searching and drop off your total hours at the boat wash. Remember, the time you spend volunteering counts toward our eligibility for grant funding to continue our essential boat wash program!
  • If you see any unusual or suspicious aquatic plants growing, take note of the exact location and immediately report the finding by contacting any Association Board of Director. Directors list  It is very important to not attempt to pull up a suspect plant. Someone with the appropriate expertise will rapidly respond to verify identification.
  • Seriously avoid all recreation in Milfoil infested areas and significantly reduce your boating speed to No Wake when travelling near infestation sites.  Wave action, a propeller, a paddle, swimming or even a fish hook can cause fragments of the brittle Milfoil plants to break off, spread and grow in new areas of the lake!
  • Awareness is not enough!  As active users of our water resources, it is important for citizens to participate in our governmental processes to develop and implement legislative solutions that affect our water resources.  Check out this web page for easy ways to participate in public policy processes to protect our waters.
  • Drop off your deposit bottles/cans at the Boat Wash and donate the refund to help fund the Boat Wash. Every little contribution helps!
  • Give a donation of $50 (or more if you would like) to be used specifically to sustain our Boat Wash and Lake Monitoring programs. donate

Our Association is committed to preserving and promoting the healthy ecology of the lake and to ensure pristine water quality for the benefit of current and future generations.