Action on caustic problem

Press, 23 February 1980, Page 4

Action on caustic problem

The Waimairi County Council has altered facilities at its Burnside Park watertreatment station to prevent any further incidents of stream pollution.

Fish were distressed, and water in the Waimairi Stream was discoloured, after a January accident, Christchurch Drainage Board members have been told.

Up to 250 litres of caustic soda solution was spilled

after a mixing tank at the treatment station had been overfilled. The spilled chemical had been hosed into the stormwater system, and eventually reached the stream.

Later, the solution was pumped to a Drainage Board sewer in Avonhead Road. Board members were told that council staff had done their utmost to prevent such a spill occurring again. A retention tank for such chemical solutions has been

installed, and is big enough to contain spillages.

Similar tanks will be installed at the other two county pumping stations where caustic soda is used. Council staff said there was never any danger to the public water supply. Next year, the council will stop treating water with caustic soda, because the method has become too expensive. New equipment will use calcined dolomite, a dryfed material.