ANS Inspections

Help prevent the spread of Aquatic Nuisance Species (ANS) by keeping your vessel clean, drained and dry, and by utilizing the green seal program.
Anchor inspected for ANS
Colorado Parks and Wildlife staff inspect a boat for aquatic nuisance species.

Vessel inspections are a mandatory part of boating in Colorado. As a headwater state, it is important that our reservoirs and water sources are protected in every way possible. Invasive species are not only destructive in ecological ways, but economical ways too. Invasive mussels can clog pipes, for example; and plants like Eurasan watermilfoil can be retracted into motors, wrap around propellers and even create harmful swimming conditions for recreators or dangerous shorelines for wading anglers. 

Every season, to combat the devastating effects of Aquatic Nuisance Species, Colorado Parks and Wildlife (CPW) employees will spend thousands of hours inspecting and decontaminating boats at WID (Watercraft Inspection and Decontamination) stations.

Decontamination of suspect boat
A boat that is suspected to have possible invasive species attached is decontaminated.

A vessel inspection can be a combination of a simple tactile and visual examination or, if there is evidence of positive or suspect ANS because of inspection results or launching history, it will lead to decontamination of the vessel. Much of this process, including a faster inspection and launching experience, is influenced by whether or not a boater stops for an exit inspection and obtains a green seal.

While inspections are required, one of the most common reasons for a mandatory decontamination is the lack of a green seal being affixed to a vessel, certifying its previous launch location.  

In this article, we will discuss what a green seal is, how it works, when a boater can use a green seal “as” an inspection and why “green” does not automatically mean “go.” 

Green seal application
CPW staff attaches a green seal. Green seals document the vessel’s inspection and launch history to determine if a decontamination is necessary.

What is a green seal?

A green seal is a small, plastic brick with a seven-digit serial number on one side and the name of the reservoir at which it is applied on the other. CPW and partnering agencies use this information to document the vessel’s inspection and launch history to determine if a decontamination is necessary. It also helps inspectors to assess the risk, or determine how likely it is, that a vessel could be transporting invasive species. 

How does it work? 

When a boater leaves a body of water, they are required to pass by the reservoir’s WID station for what is called an “exit inspection.” During this process, the inspectors will ensure that center and/or bilge plugs, plant fragments, mud or water is removed from the vessel before applying a green seal. Boaters also have the option to get a decontamination at this time. 

Whether performing an inspection or decontamination, when the inspector is satisfied with the condition of the boat at the exit inspection, they will provide the boater with a receipt.

What is a receipt?

A receipt documents what type of inspection or decontamination has been performed, and also which parts of a vessel were inspected or decontaminated on site. This receipt will either be a blue or white piece of paper with the reservoir’s name, the inspector identification number, the vessel’s registration number (or Hull Identification Number) and trailer information, and also the types of invasive species that are known to reside in that body of water. The color of the receipt indicates whether the reservoir the vessel was at last either contains/is positive for ANS or does not. 

  • A blue receipt means a location has a known population of ANS.
  • A white receipt indicates that a reservoir does not have ANS. 

Boaters are encouraged to keep their receipts in a secure place as they will be asked to provide the receipt during their next entrance inspection. It is especially important for vessels exiting Highline Lake, as vessels will be subject to further decontamination if there is no physical receipt showing proof that they were already decontaminated and inspected prior to their departure. 

Why “Green does not mean Go”

The color of the receipt is more important than the color of the seal. Even if a boater has a green seal, if the reservoir they are coming from is contaminated with ANS, they must receive an in-person inspection from a state-certified agent prior to launching. To mitigate the risk of transporting ANS, a boater should be ready to participate in an inspection if they are launching at a reservoir without ANS. 

Seal drop location
Boaters are asked to drop their seal and receipt into designated receptacles for rangers and staff to check the next morning.

When the seal can take place of an in-person inspection

At select locations, boaters have the option to launch without an in-person inspection if they are utilizing the green seal program properly. Boaters can launch at many reservoirs that are open past business hours providing they meet the following requirements and fill out the required logs: 

  • The vessel is returning to the same body of water 
  • The vessel is coming from a body of water that is free of ANS and the boater can provide a white slip 

To launch in the above conditions, there is typically a form available to boaters to fill out which will request information such as the vehicle license plate number, a trailer number and the seal information. Boaters are asked to drop the seal and receipt into the designated receptacle for rangers and staff to check the next morning. Boaters should take special care to provide this information and ensure that the above requirements are met; failure to do so can result in a citation. 

The chief priority is conservation. Active participation of both staff and recreators not only helps provide CPW with pertinent information, but also aids boaters as well. The green seal program is an invaluable system that allows staff to decrease quantities of resources and also time performing decontaminations. It is a collaborative effort and is one of the most important working relationships sustained to aid conservation efforts and preservation of our lakes and reservoirs. 

Vessel exit inspection
Vessels are inspected when they exit the lakes and reservoirs.

Learn more about CPW’s boat inspection and decontamination program on our website.

Written by Devan Walsh. Devan is a CPW digital communications specialist.

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