Council to Review Processes Following Overflow
18 July 2011
An independent review into the recent overflow at Hamilton’s Wastewater Treatment Plant found there was a good response
to the spill, but that some improvements could be made to processes.
Council has already implemented a number of the recommendations contained in the report by consultants MWH into the 31
July spill, and has an action plan to ensure the completion of the remaining actions.
The report found that around 112cu m of fully treated material, 20 percent less than originally estimated, entered an
unnamed tributary, with a lesser unknown amount reaching the Waikato River. No adverse impact on the river was detected.
A number of factors were found to have contributed to the spill including: mechanical failure with centrifuges; alarm
settings in the Plant’s day tank; an accumulation of rags, hair and other material which blocked an overflow pipe; and
clarity and response to standard operating procedures.
While Council was found to have responded well to the spill and subsequent cleanup, improvements could be made to
processes and training. Work is already in train to implement all recommendations.
The report also identified that Council’s current $32 million staged upgrade at Pukete Wastewater Treatment Plant will
bring significant improvements to operations.
City Infrastructure General Manager Chris Allen says:”Protecting the environment is a very important part of the work we
do as an organisation, and we are always looking at ways to continually improve our processes and procedures in response
to this challenge.
“Incidents of this nature are regrettable but I am pleased with the response to minimise the environmental impact.
There’s always lessons to be learned and we are already well underway in implementing all of the recommendations in the