Preston Road Wastewater Treatment Plant
During late Monday night (10 May 2021) an electrical fault occurred with the electronic control systems which affected the two high flow pumps that pump partially treated effluent from the Preston Road site to the Johnston Street site.
While a spare pump was deployed this was only able to pump about 25% of the flow to Johnston Street, with the rest of the partially treated effluent overflowing and discharging to the lagoon adjacent to Sawyers Creek.
On Wednesday afternoon a new electronic control system was installed. The overflow ceased around 5pm yesterday. All partially treated effluent from this time is again being pumped to Johnston Street for final treatment before discharge to the Grey River.
The West Coast Regional Council was notified on Tuesday and visited the site on the same day. Since the raw effluent coming into the Preston Road Plant is being partially treated through milli screens and the biological trickling filter (the big tank seen on site), the overflow discharge did not contain any solid materials and was a clear liquid with no odours.
Staff are sampling the quality of the water in the lagoon to confirm the level of contamination that occurred compared to pre-event conditions and will continue to monitor until the lagoon water returns to the pre-event conditions.
While it is unlikely that there will be any contact recreation in the water ways, the public is advised not to use these areas until Council confirms the water has returned to the pre-event conditions. This is expected to occur over the next few days. Information will be posted on Council’s website and Facebook page.
Council apologises for any disruption and inconvenience this event has caused.