Masterton District Council [MDC] is working on a fix for sewage flowing onto properties in a central Masterton street during severe weather events.
Yesterday a council spokesperson said three of the approximately 20 properties on Cockburn St that are potentially impacted by the wastewater flooding problem are now on track to get a temporary fix.
A similar remedy could also be applied to the other affected properties, although this particular solution might not be appropriate for all of them.
The 20 or so properties in Cockburn St are impacted to varying degrees by wastewater flooding in extreme weather.
Residents have previously told the Times-Age of their properties being regularly inundated by untreated sewage when it rains heavily, with the problem worsening over the past year.
They described human waste flooding their yard, blocking their drains and, in one instance, even possibly coming up the drain into the kitchen sink. For some, toilets were not emptying, and MDC had provided portaloos.
Mike Burger, MDC manager of assets and operations, said tanks on three individual properties are now ready to install when written authority to proceed has been received from the property owners.
Further tank installations to affected properties will be considered once the initial three are successfully commissioned.
The three letters of authority were reportedly due to be sent yesterday; one to be delivered to the property owner, and two by mail because the owners are not the occupants.
“The council believes the installation of collection tanks and non-return valves will be a temporary approach until renewal works to the network have eliminated sewer network infiltration,” Burger said.
The fix involves installing a 3600-litre tank on each property, and a non-return valve in the ‘lateral’ pipe running to each house. The valve and tank will prevent sewage from flowing back up the laterals, which will be re-lined to prevent groundwater from coming onto the property.
“In normal circumstances, wastewater will flow into the main. When there is high flow in the sewer main, the non-return valve will prevent the backflow of wastewater, which is directed into the tank. Tanks have capacity of at least three days flow and will be pumped out as required,” Burger said.
Burger said relining of sewers is underway to prevent the leaking of groundwater into sewer lines.
“This is the primary cause of infiltration of sewers backing up.”
MDC’s current Long Term Plan provides for a $1.2 million spend on sewer renewals in the next financial year, including relining. A further $2.25 million has been allocated to
upgrades of Masterton’s wastewater network from central government ‘Better Off’ funding.
Burger said MDC is also considering increasing funding allocated to wastewater upgrades.
“A total of $1.5 million was spent on this work last year.”
