TGPC: Greater Wellington letter to Chair, PCTG BOI - Attachment 2

*Literature review of Porirua Harbour and catchmentAppendix 2: Annotated Bibliographyassessed water quality for shellfish gathering. Sites sampled in POTirua Harbour areamongst the worst for compliance with recreation guidelines. Sites that most frequentlyexceeded guidelines included Browns Bay, South Beach PIimmerton, POTirua Harbour atthe rowing club and PIinunerton Beach at Bath St. Discusses each sampling site'spercentage compliance and coincidence with rainfall. Most exceedanCGs are related torainfall and contaminants are likely sourced from urban runoff. However, manyexceedanCG events coincide with little or no rainfall, and the cause of these highmicrobial counts is unclear. fits possible that nearby streams are influencing the nearbywater quality. Bestlevels of compliance were at the Water Ski Club, Moiukaraka Point,Karehana Bay, Paremata Beach and Onehunga Bay (all 87 90% compliance). Samplingresults at Te Hiko were consistently poor, and clearly indicates that site was riot suitablefor swimming, so a permanent sign was erected and monitoring ceased. Water quality inrelation to shellfish consumption was undertaken at To Hiko, and was unsafe for shellfishgathering or consumption, based on collected samples and other water quality resultsMilne, I. R. (2006b). 011 the benches. Reci'euiional water quotrty for Ihe Welling!o11 Region,2005-2006. Greater Wellington Regional Council, Report N"' GW/RINV-G-06199Routine recreational water quality as initiated with Berry (1996b). Similar to Stephenson(2004). 14 sites monitored in POTirua Harbour; none of these exceeded the enterococciguidelinesMilne, I. R. (2007). 011 lite benches. 2006/07 Annual recreational water qwali!y 1110niioringyeporijor Ihe Welling10n Region. Environmental Monitoring and Investigations Department,Greater Wellington Regional Council, Report No. GW/EMI-T-07/126Routine recreational water quality as initiated with Berry (1996b) and similar toStephenson (2004). 14 sites monitored in POTirua Harbour; of these 12 sites exceeded theenterococci guideline values once, and 4 sites twice or more. In 2005/06 no sitesbreached the guidelines. Could notidentify obvious cause of contaminationMilne, I. R. (2008). AnHunt codsiu11110/1iiori, 18 yeporifor 1/7e Welling1011 Region, 2007/08Environmental Monitoring and Investigations Department, Greater Wellington Regional Council,Publication N" GW/EMI-G-08/162.Summary of routine summer and annual coastal sampling of water quality in terms ofenterococci and faecal coliforms, in order 10 assess health risks. Data in appendix.Summarises reports commissioned for sites in region including POTirua HarbourDescribes results of broadscale habitat mapping and finescale ecological mapping ofinterndal areas of POTirua Harbour (Robertson and Sievens 2008). Identifies that in botharms of the Harbour there is little to no terrestrial vegetation buffer. The estuary has amoderate sedimentation risk, and is moderately eutrophic. The total recoverable heavymetal concentrations were within ANZECC (2000) IsQG. Describes the benthiccommunity, and rates the community as 'unbalanced'.Milne, I. R. and S. Warr (2007). Annual cousinli?10/1itoriitg reportfor Ihe Well^I^gio, I region,2006/07. Environmental Monitoring and Investigation Department, Greater Wellington RegionalCouncil, Report N"' GW/EMI-T-07/224.Routine coastal water quality as initiated in Berry (1996b) and similar to Stephenson(2001). Also includes overview of a report that is being undertaken on the POTiruaHarboursystemReportfor Porirua City Council & Wellington City CouncilBlaschke and Rutherford Environmental ConsultantsFebruary 201030