Permanent Decontamination Station Feasibility Analysis

 

If eradication of dreissenids is not possible upon detection, actions must be taken to prevent spread of mussels from Clear Lake to other water bodies. Installation of adequate water/energy efficient watercraft decontamination stations must be completed to ensure that all watercraft leaving Clear Lake have no mussels on board, either attached to the vessel or floating in vessel/engine compartments, bilges, and other places that hold water. Options for decontamination stations:
 

• Fixed base systems ($225,000 to $450,000)—Hydro Engineering, LLC https://www.hydroblaster.com) produces high-capacity fixed based systems consisting of a Hydrosite insulated equipment building connected to utilities (water, power, and fuel) as well as portable systems. Permanent decontamination stations range from $225,000 (single station systems with one wash pad – drive on, drive off ramp) to $400,000-plus multiple (4-station) systems (e.g., 2 wash pads).

 

• Dip Tank ($800,000)—Clean Wake LLC (https://www.cleanwake.net/) developed a dip tank that lowers a boat into the tank and fills and empties the ballast tank while the watercraft engine is running. This type of system was first used in Utah in 2021, and decontaminates vessels faster than manual decontamination, including those with complex systems.
   

The Model Regulation for State Watercraft Inspection and Decontamination Program (Otts and Nanjappa 2016) notes an agency may establish inspection stations:

• At or along publicly accessible boat ramps and conveyance launch sites, roads and highways

• At ports of entry (if the Department of Transportation authorizes the agency to use the port of entry);

• At agency facilities;

• Where there is a high probability of intercepting conveyances transporting aquatic invasive species’

• Where there is typically a high level of boat and trailer traffic; and/or

• Where the inspection of conveyances will provide increased protection against the introduction of aquatic invasive species into a water body. In addition, Otts and Nanjappa (2016) encourages stations be sited in locations that are convenient and readily accessible to boaters, in locations with the greatest chance of intercepting high-risk conveyances, and in locations with adequate space for conveyances to be stopped, inspected, and in some cases, decontaminated, without presenting a safety risk or significantly interfering with the public’s use of the waterbody or highway. Otts and Nanjappa (2016) also emphasize environmental considerations if decontamination occurs at an inspection station because of the need for proper handling and disposal of potentially contaminated effluent.
   

Other criteria to consider:

• Locations that intercept the greatest number of watercraft.

• Fishing tournament watercraft launch locations.

• Proximity or accessibility to water, power, and sewer connections.

• Surface, slope, and distance to Clear Lake.

• Traffic patterns that capture major/preferred routes.

• Traffic patterns at proposed station location (e.g., safety considerations including preventing left-hand turns across lanes, overflow of waiting watercraft, surrounding speed limit allows ease of access and if not then adequate signage).

• Area surrounding station has clear control points to prevent boats from launching/leaving until they have been decontaminated.

• Minimal disturbance to natural landscape.

• Adequate space to house decontamination unit, structure for staff to remain
  safe, structure to house operational equipment, etc.

• Near interstate roads coming into county from direction of infested waterbodies
  (Hwy 20 by Hwy 53).

• Near or at County- or City-owned property or empty/vacant parcel that could be
  acquired with minimal capital.

• Near City/County services to tap into municipal water and special districts water
  treatment lines for the discharge.

• A location that is easily accessible and County/City owned in Lakeport.

• Use of www.AISexplorer.umn.edu may be considered for prioritization of inspection
  stations.

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Handout to use with landowners to explore potential sites
for watercraft inspection and decontamination stations.

Case Studies

These case studies illustrate a variety of factors that can be considered when developing policy associated with citing watercraft inspection and decontamination stations.

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Case Study #1 – Stearns County, Minnesota

An integer programming model was developed to allocate scarce inspection resources among lakes with a county, using species-specific infestations status of lakes and estimates of boat movement among lakes to maximize the number of high-risk boats inspected (Haight et al. 2021). High-risk boats were defined as those that move from infested to uninfested lakes. Modelers determined locating inspection stations at infested lakes that have the greatest number of boats moving to uninfested lakes both inside and outside the county would achieve the objective of protecting uninfested lakes. Alternatively, locating stations at both infested and uninfested lakes having the highest-risk boats arriving from within and outside the county and departing to in-county lakes would achieve the objectives of protecting only county lakes. The authors noted the tradeoffs between the objectives is significant.

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Case Study #2 – British Columbia

Watercraft inspection policies that prevent the spread of dreissenids can be optimized under budget constraints using linear integer programming techniques (Fischer et al. 2020). Authors noted that inspection stations should be placed close to the border of the uninfested region (emphasizing cross-border collaborations between uninvaded jurisdictions); if traffic flows merge close to the border, inspections are most cost-effective after the merging point; if traffic predictions involve a high level of uncertainty, inspection efforts should be distributed over many locations; and if a high reduction of propagule inflow is desired, it may be cost-effective to implement measures increasing the compliance rate rather than operating more inspection stations for longer hours.

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Case Study #3 – Deep Creek Lake, Maryland

Deep Creek Lake in Maryland sought to reduce the number of instances of visiting watercraft arriving at the lake contaminated with aquatic invasive species (Chase et al. 2020). Defining barriers and behavior drivers is critical to changing human behavior. The study determined that the Deep Creek Lake website and associated Maryland Department of Natural Resources sites were disconnected and difficult to navigate, including difficulty accessing information on boat launch inspection and aquatic invasive species prevention measures. Recommendations included enhancing community partnering to improve communication in the tourism community and leverage nonprofit organization funding grants, creating focus groups through boater/fishing license registrations or in-person launch steward interactions to define barriers/drivers to behavior change, improving website design, streamlining digital media to coherently and consistently communicate AIS impacts, prevention, and expected actions, and empowering boaters with on-site cleaning equipment at high-use ramps.

 

 

Suggested Training for Watercraft Inspection and Decontamination Program Staff

If the District determines that mandatory watercraft decontamination operations would be conducted, proper staff training and equipment will be needed to ensure that operations meet minimum guidelines to prevent the spread of dreissenids. The minimum standards for programs are based on the Uniform Minimum Protocols and Standards for Watercraft Inspection and Decontamination. The goal of a watercraft decontamination is to remove and kill driessenid mussels from watercraft. The basis for standard procedures is derived from applied studies that examined the lethal times and temperatures of hot water for dreissenid mussel mortality. Watercraft decontamination procedures not only include proper use of the equipment, but also personal safety, watercraft owner permission, and detailed documentation.

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There are several documents that regional AIS programs align with when conducting decontaminations, including:  

• Uniform Minimum Protocols and Standards for Watercraft Inspection and Decontamination in the Western United States (Elwell and Phillips 2021)

• Watercraft Inspection and Decontamination Manual (Western Regional Panel on ANS 2021)

• Student Training Curriculum for Watercraft Inspectors and Decontaminators to Prevent and Contain Invasive Species in the USA (Western Regional Panel on ANS 2016)

• Watercraft Inspection and Decontamination Trainer’s Manual (Western Regional Panel on ANS 2021)

 

All staff conducting decontaminations must complete training that provides a thorough understanding of the risks from invasive species and the role that watercraft play in their spread, as well as full knowledge of the proper use of all decontamination equipment. Most comprehensive watercraft inspection and decontamination programs conduct annual training events based on the curriculum noted above. Training typically occurs during a 2-day period, and includes both classroom and hands-on activities to familiarize staff with basic steps on watercraft decontamination. Different types of watercraft (size and complexity) require different amounts of time to complete decontamination, therefore training should include different watercraft types. Multi-day training is offered regularly by Pacific States Marine Fisheries Commission (see https://www.westernais.org/, Training menu tab) and Tahoe Regional Planning Agency. Appropriate decontamination units are also an important part of the decontamination process. Minimum standards for both trailered and non-trailered units can be accessed at https://westernregionalpanel.org/key-documents. Adhering to the guidelines presented in the documents in the bulleted list (above) will align Lake County program operations with western regional programs. County staff could consider the use of on-the-job training that could follow immediately after hire to enforce objectives that were covered during the training.