Learn how the NRSBU has performed against its

  • Levels of service
  • Resource consent compliance
  • Financial results
  • Annual report results

NRSBU Bell Island Treatment Ponds Sludge Survey Report 13 November 2015 (3.8MB PDF)

NRSBU Report Bell Island Sludge Survey June 2014 CONHUR 10mar2015 (7MB PDF)

NRSBU Bell Island Sludge Survey 2014 reduced report 10mar2015 web (6.2MB PDF)

Impact of the Bell Island Regional Treated Effluent Discharge on the Coastal Environment : 5 Yearly report

Download: NRSBU Report 0347 Bell Island mixing zone 5 yearly 2016 Cawthron 2945 Oct 2016 (6.1MB PDF)

The report shows that there has been no changes to the different environmental receptors indicating that the continued discharge of treated wastewater from Bell Island has no discernible impact on the environment. The report states that;

5.1.1   “Seawater stratification characteristics indicate rapid mixing of the low salinity wastewater discharge with estuarine receiving waters within the ebb tide flow channels.

5.1.2   Receiving water nutrient concentrations indicate adequate dilution down-current from the Bell Island wastewater outfall to prevent development of eutrophication.

5.1.3   Ammoniacal-N concentrations at all sites were well below ANZECC (2000) and USEPA (1986) guideline trigger levels, ensuring that potentially toxic conditions were not achieved.

5.1.4   Phytoplankton characteristics at inner Tasman Bay sites were considered to be normal for the region, reflecting the seasonally productive spring diatom growth period but showing no discharge-related signs of over-enrichment or stimulation of undesirable species.

5.1.5   Receiving water faecal coliform and enterococci concentrations indicate that the Bell Island outfall discharge was not a significant source of bacterial contamination during the sampling period.

5.1.6   Concentrations of faecal coliforms and enterococci in mussels, summarised from 16 bio-monitoring surveys (2008-2016), indicate that contributions from the Bell Island discharge were minor in comparison to catchment runoff.”