Case study – sewage treatment plants

In Northland, Far North District Council (FNDC), Kaipara District Council (KDC) and Whāngārei District Council (WDC) are responsible for thirty community wastewater treatment plants (WWTP).

All 30 treatment plants operate under resource consents from the Northland Regional Council. Twenty-four of these consents are for discharges to water while the remaining six are for discharges to land. The regional council monitors these consents on a regular basis to ensure compliance with consent conditions and to assess impact on the environment. A summary of compliance issues is shown in the table below.

All Northland councils are active participants in the Northland Sewage Accord which is coordinating improvements to WWTP. Twenty-five of the 30 district council sewage schemes have modern consents, issued in 2004 or later. Twenty-nine are less than 10 years old and four are currently being processed for replacement consents.



Actions / improvements



·              Four plants are operating well.

·              One WWTP (Mangawhai) has inadequate irrigation area to consistently comply with land application conditions.

·              The regional council is working with KDC and its contractors to sort this issue.



·              Seven plants are operating well.

·              Operational issues with two WWTP (Hikurangi and the Whāngārei main WWTP) have resulted in poorer quality effluent than required being discharged at times.

·              WDC is currently reviewing operation and upgrade options for the main WWTP.

·              Recent upgrade to Hikurangi WWTP has resulted in improvements.  Further work is required.



·              Eight plants are all operating well.

·              Fourteen management plans are outstanding.

·              Three plant upgrades have not been done (Kaikohe, Kaeo, Kaitāia).

·              Some water quality conditions of consent are not met at times at six plants (Hihi, Paihia, Taipā, Kaikohe, Kaitāia, Whatuwhiwhi).

·              Agreed schedule for management plans to be submitted.

·              Overdue upgrades are now programmed or are being worked through as part of section 127 consent reviews.

·              The regional council is working with FNDC to make improvements to bring all WWTP into compliance.


Floating wetlands.New floating wetlands installed on the Kaitāia sewage pond to reduce blue green algae.