How were zebra mussels eradicated from Millbrook Quarry?
To kill the zebra mussels through exposure to potassium, the entire quarry was injected with 174,000 gallons of potassium chloride solution over a 3-week period from January 31 to February 17, 2006. The solution was delivered each morning to the site, and then pumped from land-based storage tanks through a floating supply line to a 22-foot work boat outfitted with a specially designed diffuser assembly on its bow. Potassium concentrations throughout the quarry and in adjacent surface waters were measured each weekend during the treatment. The target concentration was 100 milligrams of potassium per liter of water (mg/l, or parts-per-million – ppm); far below the level that would invoke environmental or human health concerns, but more than twice the minimum concentration needed to kill all the zebra mussels. Sampling at various depths and locations in the quarry after treatment revealed potassium concentrations ranging from 98 to 115 ppm, and no potassium leakage from the quarry into ad
