Hahei Wastewater

Wastewater in Hahei is made up of two sources – Storm water/General run off and Sewage. On this page, we present background information on both.

Storm Water

Storm Water in Hahei is collected in the following catchments

  • Wigmore – The Wigmore Stream and its tributaries originate towards Link Road, and flows down past the sewage treatment plant before discharging into the ocean at the southern end of Hahei Beach. The Wigmore receives run from farms. treated sewage, and  storm water in Hahei Village.
  • Tutaritari – The Tutaritari Stream originates in the valley behind Grange Road, then flows over farm land, through Hahei Village, and discharges on to the middle Hahei Beach near the Beach Car Park.

TCDC is responsible for managing storm water in Hahei Village in the area within the green dotted line shown on this map. For more details go to click here.

Sewage

Hahei has a TCDC operated municipal sewage system that provides sewage treatment to 140 properties in  Hahei. The area covered shown in the map. Click here for more details.

For details of the treatment plant and its operation, you can download the RMA application prepared by Harrison Grierson, TCDC’s consultants by clicking here. Hahei Sewage System RMA Application

The area of Hahei not covered by the TCDC sewage treatment plant has a variety of treatment plants, depending on when the property was developed. Older properties have septic tanks, while more recent builds have modern onsite sewage treatment plants.

Sewage Treatment Plant Performance.

Each year, Veolia, TCDC’s plant operator, provides a detailed report of the plants performance. You can download the reports here

These reports show that the plant was compliant in 2017, but failed to meet required performance standards, as set out in the Discharge Consent, in 2018. Here is a summary

2018 Actual Performance Consent Max
90th Percentile Average 90th Percentile Average
Suspended solids (g/m3) 8.6 3.5 20 10
cBOD5 (g/m3) 10.8 3.8 20 10
Escherichia coli (cfu/100 mL) 953.0 370.5 20 10
Total Ammoniacal nitrogen (g/m3) 51.0 22.4 15 10
Total Kjeldahl Nitrogen (g/m3) 33.6 13.9 20 15
Total Phosphorus (g/m3) 13.2 7.9 20 14