Palmerston North City Council Review - Palmerston North Wastewater Treatment Plant

Horizons has completed its further work on the PNCC WWTP review and can now confirm its position which is contained in the information below. In summary, and based on the scientific and engineering reports attached, Horizons position is that the discharge is at times having significant adverse effects on the life-supporting capacity of the Manawatu River. Horizons therefore require, bay way of new and amended conditions, a reduction in the concentration of nitrogen and phosphorus discharged to the river.

Supporting documentation to the Horizons position;

Summary of Horizons position

Horizons revised consent conditions

A conditions explanatory note

Stark Environmental report on significant adverse effects

Cardno BTO engineering review report

Golders Associated Ltd ecological report

Resource Consent details:

101829: Resource consent to discharge treated wastewater from Palmerston North City Council’s wastewater treatment plant on Totara Road into the Manawatu River, issued for a term of 25 years and due to expire in 2028. 


Palmerston North Wastewater Treatment Plant, Manawatu River, Totara Road, Palmerston North.

Reason for the review:

There is excessive periphyton growth downstream of the PNCC Wastewater Treatment plant discharge which Horizons considers is related to the levels of nutrients being discharged by the PNCC wastewater plant.  

The review will focus on nutrient levels being discharged from the plant; whether the in-river limits in the consent will protect the river from excessive periphyton growths; and monitoring requirements, specifically around periphyton and macro-invertebrates.

Horizons proposed a set of new resource consent conditions.  These are included in the relevant information listed below which is available to all parties.  The consent holder, PNCC, was invited to propose new resource consent conditions.  These have been provided and are included in the relevant information.

Relevant information:

The relevant information that is available includes:

  1. Consent 101829
  2. Report entitled “Effects of Palmerston North City’s Wastewater Treatment plant Discharge on Water Quality and Aquatic Life in the Manawatu River: joint monitoring programme between Palmerston North City Council and Horizons Regional Council”
  3. PNCC response to Notice of Review – Issues and Options paper including PNCC’s proposed conditions

The relevant information information may be viewed at the following location:

  • Horizons Regional Council Office, 11-15 Victoria Avenue, Palmerston North.

You can also request a hard copy of the application from the Consents Department of the Manawatu-Wanganui Regional Council (0508 800 800) or via email