Author:Justine L Quinn, Martin W Neale
Source:Auckland Council Research and Evaluation Unit, RIMU
A review of long-term bathing beach monitoring data from Auckland Council’s (AC) Safeswim programme revealed a pattern of poor water quality due to microbiological contamination along the northern Manukau Harbour coastline. Following initial investigations within the wider northern Manukau Harbour catchment, French (Otitori) Bay, Wood Bay and Titirangi Beach were chosen for detailed investigation into potential sources of contamination within their respective coastal environments.
Fourteen sites across the three catchments were sampled over a total of 12 occasions, comprising four occasions between March and April 2015 and eight occasions between March and May 2016. In total, four freshwater (stream) sites, six coastal sites and four intertidal stormwater outfalls were sampled across the three catchments.
Microbial Source Tracking (MST) analysis was undertaken on selected samples in addition to standard faecal indicator bacteria (FIB) testing (E. coli and enterococci). All samples were compared to Ministry for the Environment recreational contact guidelines (MfE, 2003).
Auckland Council technical report, TR2018/009