Pump Stations & Pipelines

The NRSBU operates five pump stations. There are linkages between pump stations ie Wakatu pumps into the Richmond to Saxton rising main, Songer Street pumps into the Saxton to Bell Island rising main, the Saxton acts as a booster for the Richmond/Wakatu pump stations and the Saxton and Airport have a common rising main across the estuary to Bell Island. All pump stations have SCADA and flow monitoring installed.

The scheme comprises five pump stations:

Beach Road (Richmond)
Saxton Road (Stoke)
Songer Street (Stoke)
Airport (Stoke/Tāhunanui)
Wakatu (Stoke Industrial)

Pump Stations

Pump Station details

Beach Road (Richmond)

The Beach Road Pump Station receives flows from the Tasman District sewage network (Richmond, Brightwater, Wakefield and Hope communities), plus a smaller quantity from NPI (approximately 23 l/s). Flows from this pump station are pumped via a 500 mm OD PE rising main to Saxton pump station.

The pump station consists of one duty pump with a pump capacity of 176 l/s and two storm pumps with a combined capacity of 430 l/s.

Wakatu (Stoke Industrial)

Wakatu Pump Station receives flows from the Wakatu Industrial area (NCC is the sole contributor) and injects into the Beach Road to Saxton Road rising main.

The pump station consists of two pumps in a duty/standby pump arrangement. The pump capacity is currently 40 l/s and can be increased to 80 l/s by installing larger pumps.

Saxton Road (Stoke)

The Saxton Road Pump Station receives flows from NCC’s network, Alliance Group, Wakatu Pump Station and Beach Road Pump Station. Wastewater flows from this pump station are then pumped via a 710 mm OD diameter PE rising main towards the WWTP.

The pump station consists of one duty pump with a pump capacity of 192 l/s and two storm pumps with a combined capacity of 580 l/s.

Songer Street (Stoke)

Songer Street Pump Station receives flows from the NCC network and injects into the Saxton Road to Bell Island WWTP rising main.

The pump station consists of one duty pump with a pump capacity of 119 l/s and two storm pumps with a combined capacity of 217 l/s.

Airport (Stoke/Tāhunanui)

The Airport Pump Station receives flows from NCC (Tāhunanui Catchment) and injects into the Saxton Road to Bell Island rising main. Prior to 2012, the Songer Street Pump Station pumped directly to the Airport Pump Station; however, this configuration has since changed resulting in a reduction in wastewater flows to the Airport Pump Station.

The pump station consists of two duty pumps with a combined pump capacity of 183 l/s and one storm pump with a capacity of 410 l/s.

Regional Pipelines

The regional pipelines consist of rising main component varying from 150mm to 800mm diameter rising mains that link the five pump stations, to the treatment, the biosolids pipeline, and the 1,200 diameter outfall pipeline and two diffuser pipelines.

The total length of pipes is just over 155km. The pipes are mainly made of HDPE due to environmental and construction conditions.

Pipeline details

Treated wastewater is discharged to the Waimea Inlet on the first three hours of an outgoing tide. The outfall system consists of a 1200 mm diameter concrete pipeline (498 m long) with two HDPE diffuser strings (119 m long and 95 m long) and outlet riser pipes (100 mm diameter) spaced 1.7 m apart along the diffuser. This pipeline is attached to a tidal storage basin at the WWTP. As per the resource consent (RM171238) the average daily discharge of treated wastewater to the inlet shall not exceed 20,000 m3/day, while the maximum volume of treated wastewater over any 24-hour period shall not exceed 25,000 m3.