WATERTOWN, S.D.(KXLG)- Zebra mussels, an invasive species that has infested Lake Kampeska, are now causing problems for the irrigation system at the city-owned Cattail Crossing Golf Course. During a Watertown Parks, Recreation, and Forestry Board meeting today, Golf Course Maintenance Supervisor Scott Schunter provided an update on the issue.

Schunter reported that approximately 40 of the golf course’s 800 irrigation heads, about 5%, are currently being affected by the mussels.

Schunter has been researching potential solutions, consulting with industry experts, and irrigation installers.

The goal of the acid injection is to lower the irrigation water’s pH below 6.9. At this pH level, the “veligers,” which are the young, free-swimming larval stage of zebra mussels, are killed upon entering the system, preventing them from developing into the problematic adult mussels that cause clogging.

Schunter is awaiting a cost estimate for the acid injector system. His initial rough estimate is in the $20,000 to $25,000 range. He is “cautiously optimistic” that the final cost will be lower.

To illustrate the importance, Schunter noted that since April 23rd, the golf course has already spent approximately $3,200 in man-hours and materials addressing the clogging issue. This manual clearing of affected heads is a continuous effort, highlighting the need for a long-term solution.

Schunter explained that while zebra mussels have likely been present in the system for a couple of years, their population hadn’t reached a problematic level until now. A contributing factor this year is the remnants of dead mussels from last year that are now moving through the system after the irrigation lines were blown out for the winter.

Addressing concerns about intake screening, Schunter stated that any filtration system fine enough to block the microscopic veligers would significantly reduce the water flow needed for irrigation (1650 gallons per minute).

He has scheduled a diver to inspect and clean the lake intake once the water warms up to assess the situation there, which also led to the discovery that Watertown Parks, Recreation, and Forestry Director Dusty Rodiek is a Certified Diver.

Looking to the future, Schunter suggested that installing an acid injection system immediately with any new irrigation system would be the most effective way to prevent zebra mussel problems from the outset.

The proposed acid injector would be located at the pump house, after the pumps and before the water enters the main irrigation system. The Parks, Recreation, and Forestry Board will likely discuss this issue further as Schunter obtains more concrete cost estimates and explores implementation options.