Aquatic Invasive Species

Aquatic Invasive Species Banner


What is a decontamination?

A decontamination is a treatment that can involve a series of procedures to kill aquatic invasive species (AIS).

When is a decontamination required?

The Manitoba government’s Aquatic Invasive Species Regulation under The Water Protection Act requires decontamination of:

Who can conduct a decontamination?

Decontamination of a conveyance (e.g., watercraft, ORV, etc.) can be conducted:

Decontamination of water-related equipment can be conducted:

Where can I go get a decontamination?

Decontaminations can be performed at any of the Manitoba government's Watercraft Inspection stations. There is no fee for this service. Priority will be given to watercraft or water-related equipment that are required by law to be decontaminated. Courtesy decontaminations may be performed as time allows.

For up-to-date information on the location and operating hours of the Watercraft Inspection stations, click here.

Step-by-step method to self-decontaminate a watercraft, trailer and other water-related equipment (Schedules B and C)

The AIS Regulation prescribes thermal treatments, using either heat or cold to kill AIS, including Zebra Mussels, for watercraft and trailers. Thermal treatments can be used also to decontaminate water-related equipment, in addition, to other treatment options that can be found here. When using the hot water treatment there is no need to use soap or chemicals.

Important decontamination information

  • The decontamination measures described must be used on land away from any water body, roadside ditch or drainage system such as a storm sewer.
  • Do not attempt a decontamination using a car wash facility. Water temperatures are inadequate and may fail to kill AIS such as Zebra Mussels possibly resulting in their spread to:
    • the facility's infrastructure
    • municipal infrastructure
    • a water body through a drainage system such as a storm sewer
  • Before beginning a decontamination for a conveyance (e.g., watercraft) and water-related equipment, consult the owner's manual and the manufacturer’s specifications to make sure the equipment can withstand required temperatures and pressures.

Decontamination of watercraft and trailer

The watercraft and trailer may be decontaminated following Schedule B by:


The thermal treatment is the most important step of the decontamination as it is required to kill the AIS. If needed, after the decontamination (i.e., thermal treatment), a high pressure spray can be used to remove any remaining attached AIS, such as invasive mussels. The priority is to KILL first, then REMOVE second. Never use high pressure water to conduct a decontamination (thermal treatment).

Method A: Approved decontamination methods for watercraft and trailer using hot water

Step 1.
Treat the exterior of the watercraft or water-related equipment using hot water (minimum 60 C / 140 F).


Figure 1. A watercraft inspector conducting a watercraft decontamination. The end of the hose is no more than 10 cm away from the surface being thermally treated with hot water.

Step 2.

Decontaminate the watercraft engine by:


Note: To facilitate motor draining, raise and lower the motor several times. For outboard motors, moving the motor side-to-side can also aid draining.

Step 3.

Treat compartments such as the live well, bait well, wet storage compartments and bilge areas by:


Step 4.

Treat ballast tanks by filling with hot water (minimum 55C / 122 F) and let stand for a minimum 130 seconds before draining.

Step 5.

Dry the watercraft completely before placing into another water body.

Note: the time it takes for watercraft to dry completely increases dramatically in the spring and fall due to cooler temperatures and increased humidity. Use a towel to remove residual water, keep all compartments open and the watercraft uncovered to facilitate drying.

Method B: Approved decontamination methods for watercraft by exposing to freezing temperatures

Step 1.

Expose the watercraft to temperatures below -10 C / 14 F for three consecutive days

Step 2.

Ensure watercraft is dried completely before placing into another water body.

Decontamination of water-related equipment (e.g., docks, fishing gear, nets, inflatables)

The methods to decontaminate water-related equipment following Schedule C can be found by clicking here.

Removal of remaining attached AIS such as adult Zebra Mussels

Use of high pressure can assist with the removal of thermally treated AIS such as adult Zebra Mussels that were not removed from watercraft and water-related equipment prior to decontamination. This additional step ensures you are not in possession of dead Zebra Mussels, which is prohibited.

A power washer capable of producing 3,000 to 3,500 psi can be used to physically remove attached AIS. A 40-degree flat fan spray is recommended. Do not use a pinpoint (zero-degree) spray, as this could damage the watercraft. The use of high pressure may cause damage to some areas (e.g., gimbal area, transducers, motor, trim tabs) thus these areas should be avoided.

Spray the watercraft from 12-16 inches away at a 45 angle from the surface. With the flat fan spraying vertically, move the wand horizontally to systematically cover all areas of the watercraft hull and trailer which were exposed to surface water.

Disposal of detached materials from high-pressure treatment

Collect all removed materials dislodged from the watercraft and water-related equipment using the pressure treatment in a sealable bag and dispose in the trash.