Monitoring Norske Skog Cooling Water Discharge to Eight Mile Creek

"November 2000".

Project Number: Monitoring Norske Skog Cooling Water Discharge to Eight Mile Creek.

MDFRC item.

42 pages.

Eight Mile Creek is an ephemeral stream that dries to pools over the summer period. The catchment drains the hills to the north of Albury, flowing through grazing land before joining the River Murray, upstream of Albury. The Norske Skog newsprint mill is situated to the north-west of Eight Mile Creek (EMC), at Ettamogah, N.S.W. In the mid nineteen eighties an arrangement was developed which saw the mill discharge treated processed water into EMC via a scour valve in its return water pipeline. This discharge was done in the summer time and the water was used by the Thurgoona Golf Club (downstream) to irrigate fairways and greens on its course. Prior to 1996 this water was a combination of treated effluent and cooling water. After 1996 only cooling water was discharged. As part of EPA licence negotiations in 1999, Norske Skog (NS) was required to examine the ecological impacts on EMC associated with the summer discharge. The licence required an environmental survey of EMC to be conducted over a 12 month period. Summer discharges of cooling water were to be ceased intermittently in order to attempt to simulate a more natural flow regime. This study investigated the ecological effects of cooling water discharges on the natural environment of EMC. This was undertaken by monitoring the physical and chemical properties, and the microinvertebrate and macroinvertebrate community compositions at three sites on EMC and at a site on each of two nearby reference streams, Woolshed and Corrys Wood Creek. The two reference streams were investigated to enable comparison between the receiving stream (EMC) and streams under a more natural wetting and drying regime. The survey was to be conducted between June 1999 and June 2000.