On Wednesday this week local residents brought to my attention raw sewage overflowing from a stormwater pipe in Meadowbank
I visited the site and sadly found this to be true with wet wipes, tampons and excrement obvious and disgorging into the Purewa Creek. Within 30 mins of my call, Watercare was on site to fix the problem
By way of background, the wastewater network in this area was predominately constructed in the 1950’s, by Housing New Zealand. It is a purpose-built separate wastewater network and currently has sufficient capacity for dry weather flows.
Watercare’s latest system performance assessment of the Purewa wastewater network indicates that small sections of the wastewater network will require upgrading to provide capacity for growth based on the land use changes and upzoning provided in the Operative Auckland Unitary Plan.
I will be pushing hard for those upgrades to happen
The are two engineered overflow points within the Purewa wastewater network that allows wastewater to spill during heavy rainfall or when blockage occurs in the network. These are network relief points and are designed like this to reduce the risk of overflows occurring on private properties
The wastewater overflow that I observed at the creek was a result of a blockage in the network due to fats and wet wipes/rags. The fat congeals and the non-flushable wet wipes bind with the fats and creates the blockage. The attached photo and video shows one of the wet wipes/rag, which do not break down and remain in one piece.
Watercare will shortly be sending out a customer newsletter to our Purwea customers, which will provide information on how to help reduce local overflows. Anything you can do to assist in that education and awareness will be greatly appreciated.
Watercare have also installed monitors at each of the engineered overflow locations. These monitor the performance of the network and we will send an alarm when a dry weather overflow occurs, which will allow Council to respond rapidly.
Watercare also intend to modify the two engineered overflow points to lessen the frequency of overflows during wet weather. They aim to have this completed within a few weeks.
I understand that there could be up to 60 properties that have historical consented stormwater (roofs and paved areas) connections to the wastewater network. Healthy Waters ( Councils regional water quality department) will be carrying out field investigations of the drainage connection status of these properties during December 2018, and based on the outcome they will look to construct new stormwater infrastructure to allow the 60 properties to connect to the new stormwater pipes.