On May 21, 2010, a diver found a live, adult quagga mussel attached to the underside of one of the boat docks in Sand Hollow Reservoir. The invasive mussel was removed, and the Utah Division of Wildlife Resources immediately implemented a rapid-response strategy to contain any undiscovered invasive mussels, keeping them from being spread to other water bodies.
Sand Hollow was declared "infested" with quagga mussels by the Utah Wildlife Board as defined in Rule R657-60. The reservoir, will retain an infested status and managed under authority of a control plan until no evidence of quagga mussels occurs for several years. Regulation of boaters under authority of the plan follows:
All departing boaters are required to decontaminate as per Rule R657-60.
Regarding decontamination, boaters must clean and drain their boats and other wetted equipment as they remove it from the water. Then, they can dry their boats and equipment at home before another launch — seven days in summer, 18 days in spring and fall, and 30 days in winter, or expose properly winterized equipment to 72 hours of perpetual freezing temperatures. However, professional decontamination services using scalding hot water (140° F) are available without cost at the reservoir for boaters who intend to use another water body before they become fully dried. Boaters using Sand Hollow Reservoir as the last water visited and returning to Sand Hollow Reservoir may do so without drying out their equipment, but it must be clean and drained of all raw water. Expect to be closely inspected if your boat and equipment are wet.
Divers and monitoring crews from the Utah Division of Wildlife Resources, Utah Division of State Parks and Recreation and the Washington County Water Conservancy District have searched the reservoir on multiple occasions, but found no sign of additional mussels or their veliger larval form. This is good news, However, in 2011 quagga mussel DNA was detected. Since the DNA discovery was not supported by microscopy showing a quagga mussel life form, it is considered an "inconclusive" discovery. Sand Hollow Reservoir continues to be managed as an "infested" water body. With the help of boaters, additional inoculations by invasive mussels can be averted. Possibly, this effort may lead to a population crash in any undetected mussels, if they exist, by keeping new inoculations away.
Please help: always decontaminate at the conclusion of a boating excursion!