Fat spill cleanup costs $540k
A fat spill that clogged New Plymouth’s sewerage system cost the district council $542,000 to clean up, it has been revealed.
In September last year, about 60 tonnes of tallow, a hard fatty substance made from rendered animal fat, ended up in the sewerage system after a mishap at GrainCorp Liquid Terminals.
The fat – enough to fill just over two 20ft shipping containers – left hundreds of residents unable to flush their toilets for several hours.
In an emailed statement, New Plymouth District Council three waters manager Mark Hall said the investigation was ongoing.
‘‘The total cost of the operation was about $541,000 and we will be seeking to recover all these costs from GrainCorp,’’ he said.
The council will be invoicing Graincorp for the money.
Members of the council’s Finance, Audit and Risk Committee were given an update on the matter, described as ‘Operation Tallow’, at their meeting last week.
The issue was also raised in a report to Taranaki Regional Council’s Consents and Regulatory Committee last month as an update. The report noted three abatement notices and three letters requesting explanation had been issued.
‘‘Investigation found that there was a white/yellow substance on Ngamotu Beach near the Hongi Hongi Stream approximately 30 metres long, and there was also a slight sewage odour near the Hongi Hongi Stream outfall.’’
Further investigation was carried out at the Port Taranaki site and it was found that a discharge of hot tallow from a tallow site had entered the trade-waste system, due to the interceptor (a mechanism to control flow) from the tallow site being left open, the report said.
‘‘The liquid tallow had solidified in the sewage system, resulting in the blockage of the pumps at the pump station and subsequent sewage discharge.’’
The company explained that the fat had been discharged from a sight glass (a transparent area in a tank to see inside) on a storage tank.
‘‘Reinspection found that the abatement notices were being complied with and that extensive remediation works had been undertaken within the tallow site and the trade waste system. Further enforcement action is being considered.’’
The report also noted that in December, some tallow ‘‘discharged during a previous incident’’ had dislodged from an unused trade waste line and blocked an interceptor.
This caused molasses to discharge, and there were ‘‘minor effects found in the sea’’.
The company cleaned the lines immediately, but enforcement action is being considered.