Drying Time Estimator for
Zebra/Quagga-Mussel Contaminated Boats

If a boat moved from an infested area will be launched in waters that are not infested with zebra or quagga mussels, the general recommendation is to keep the boat out of water and let it dry for a minimum of 30 days after cleaning all equipment and draining all possible sources of standing water. However, such "quarantine" times may be reduced depending on local temperatures and relative humidities.

In general, zebra and quagga mussels can survive longer out of water if local conditions are cold and humid than if conditions are hot and dry. This tool estimates recommended quarantine times based on average humidity and temperature zones in the 48 contiguous United States.

If a boat has been in infested waters, please use this tool to estimate the minimum time it should remain out of water (after being cleaned thoroughly), before launching in uninfested waters. Recommendations are only guidelines for average conditions and are based on evidence from laboratory experiments where other factors are held constant. Thus, recommended quarantine times may not produce 100% mortality under real-world conditions where unidentified, yet contributing factors are free to vary. This tool will provide a minimum quarantine time that you may need to adjust upward if your situation includes additional contributing factors that may be important.

Along with this tool, please use your best judgment before launching a
potentially contaminated boat in uninfested waters.

Select a month in the drop-down box below and then click anywhere on
the map to get an estimated quarantine time for that location and time.

Note: both layers (temperature and humidity) are used in the estimation regardless of which one is currently showing.

Recommendations are based on U.S. Army Corps of Engineers Contract Report EL-93-1, June 1993, "Use of Emersion as a Zebra Mussel Control Method" by Robert F. McMahon, Thomas A. Ussery, and Michael Clarke, The University of Texas at Arlington.

Humidity Zones are based on the United Nations Environment Program's World Atlas of Desertification, 2nd Edition, 1977. Nick Middleton & David Thomas (Editors).

Temperature Zones are based on archived 2005 data from NOAA/National Weather Service, Climate Prediction Center.