lake gets dose of medicine

Lake gets dose of medicine
17.08.2005

By KRISTIN MACFARLANE in Rotorua

A mineral aimed at reducing the risk of unhealthy water conditions and threats to aquatic animals has been applied to the surface of Lake Okareka.
Phoslock is a natural absorbing mineral made up of mostly bentonite, which is mainly dirt, and 20-tonnes of it is being pumped into the lake this week.
The mineral makes contact with phosphorus, which can cause unhealthy conditions that can threaten aquatic animals if there is too much, locking it up so it sits on the bottom of the lake.
The phoslock application at Lake Okareka is part of Environment Bay of Plenty's action plan aimed at getting rid of some of the nutrients which are degrading the water quality in Rotorua lakes.
Environment Bay of Plenty's environmental investigations manager John McIntosh said he expected the phoslock to easily slash the amount of phosphorus in Lake Okareka.
"We need to reduce the phosphorus going in by 80kg a year, this reduces [it by] 100kg a year," he said. The process would be repeated in the lake for the next three years with the next application of phoslock due next May.