5. Customer’s Sewerage System

5.1 General

1. The customer’s Sewerage System is governed by the Building Act from inside the building to the point of discharge. The Council may not impose anything on the customer which is more onerous than is contained in the New Zealand Building Code.
2. The customer’s Sewerage System shall be designed, installed and maintained, both in its component parts and in its entirety, to ensure that it complies with the Building Act and the New Zealand Building Code.
3. Drainage from premises constructed, or for which construction was commenced, prior to the coming into force of the Building Act, does not need to be upgraded to meet the requirements of the New Zealand Building Code. If however any work is required on the Customer’s Sewerage System, arising from:
   1. The issuing of a defect notice;
   2. Alteration to the premises;
   3. Change of use of the premises
      then any such work shall meet the requirements of the New Zealand Building Code.
4. Customers with discharges from Premises not covered by the Building Act and the New Zealand Building Code shall nevertheless have a sewerage system which complies with the Building Act and Code.

5.2 Blockages

1. A customer whose gully trap is overflowing or has other reasons to suspect a blockage, shall first call their drainlayer to clear and remove any blockage in their private sewer.
2. If the drainlayer finds that the blockage is within the Public Sewer, then the drainlayer shall contact the Council who shall clear and remove the blockage and clean up all affected areas.
3. Provided that the blockage has not been forced downstream into the Public Sewer in the act of clearing it from the private sewer, or that the customer has not been negligent in discharging a non-acceptable Wastewater, then the Council shall reimburse the customer for actual and reasonable drainage costs. If otherwise, the Council shall recover the costs of the unblocking work from the customer.

5.3 Trees

1. In the event of the roots of any tree on a Customer’s premises causing or being likely to cause damage, interference to the flow, or blockage to a Public Sewer the Council procedure shall follow that set out in the Local Government Act 2002.

Note that the law does not differentiate between a Public Sewer on private or public land, i.e. the Occupier or Owner cuts down or removes the tree at their expense with no compensation payable.

5.4 Infiltration

1. Stormwater shall be excluded from the Sewerage System by ensuring that:
   1. There is no direct connection of any stormwater pipe or drain to the sewerage system
   2. Gully trap surrounds are set above stormwater ponding levels (refer New Zealand Building Code G13), or secondary overland flow path flood levels;
   3. Inspection covers are in place and are appropriately sealed.
2. Stormwater which is contaminated may be accepted as a trade waste discharge Refer to the Trade Waste Bylaw.
3. For large impervious areas (e.g. stockyards or truck washing facilities), specific provision shall be made for a permanent barrier which will prevent water from outside the confines of the facility from entering the sewerage system. This could be by way of a nib wall, speed humps, or appropriately graded surrounds.
4. Where it is impractical to cover a large impervious area, consideration shall be given to a system which detains run-off from the "first foul flush" for ultimate disposal to the Sewerage System, with subsequent run-off disposal as stormwater.
5. Private Sewers shall be kept and maintained in a state which is free from cracks and other defects which may allow infiltration.

5.5 Pump Stations

1. Private sewerage pump stations will be approved only where there are no practical alternatives for a gravity flow discharge to the public sewer.
2. A private sewerage pump station for a single dwelling unit represents an alternative solution in terms of the Building Act. As such, the customer (owner) will be required to demonstrate that the pump station complies with the provisions of the New Zealand Building Code when seeking a consent.
3. A private sewerage pump station serving more than one residential dwelling unit requires a compliance schedule as well as an annual building warrant of fitness in order to meet the requirements of the Building Act.
4. A "Common Pump Station Agreement" shall be required between the parties, including appropriate maintenance of rising mains. It shall be registered against the Certificate of Title of each party.
5. The combined rate of discharge to the public sewer shall not exceed the rate specified by the Council.

5.6 Swimming and Spa Pools

Customers with swimming or spa pools shall be required to demonstrate that the pool sewer has been fitted with a flow limiting device to ensure the discharge does not exceed the maximum instantaneous flow requirement of 2.0 litres/sec.