This is an HTML version of an attachment to the Official Information request 'Above ground sewage tanks'.
Hi Ricard

We have spoken with our Chief Wastewater Advisor regarding the proposed wastewater storage tanks for 79 Taranaki Street.

The advice given is :

· that the tanks should be underground – and preferably constructed from fibre glass

· discharge should be controlled by an actuated valve for holding – normally open, close based on level in public main

· the valve will be controlled by an ultrasonic and back up level switch – located within a public wastewater manhole

· Proposed to use existing WW MH – WW35568 – highlighted below. This has a calculated invert level of 5.62m MSL – and has an approximate depth of 1.5m. The level and ability to connect by gravity will need to be confirmed.

· An overflow alarm will be required connected to the WWL system and a red flashing light on the side of the building

· All maintenance, repairs and renewal will be the responsibility of the building owners. Manuals, maintenance schedules etc. will need to be produced and made available for the building owners.

· The tanks will need to be located so that access by a sump truck is achievable

· Can it be confirmed that the flow/discharge rates used have come from the Regional Standard for Water Services



Sheryl Barker Senior Drainage Engineer - Land Development

Tel +64 4 912 4465 [mobile number]

Private Bag 39804, Wellington Mail Centre 5045
Level 4, IBM House, 25 Victoria Street, Petone, Lower Hutt<>

Wellington Water is owned by the Hutt, Porirua, Upper Hutt and Wellington city councils and Greater Wellington Regional Council.
We manage their drinking water, wastewater and stormwater services.