30 July 2013

Report gives thumbs up for Wellington’s swimming spots

Most of Wellington’s popular swimming spots provide safe swimming with 67 of the 85 sites monitored found to have ‘fair’ to ‘very good’ water quality.

The Wellington 2012/13 recreational water quality report On the Beaches was released this week. This report presents the results of weekly recreational water quality monitoring undertaken over the 2012/13 summer bathing season (November to March) as well as updated ‘suitability for recreation’ grades for each site.

The monitoring included analysis of faecal bacteria or E. coli at freshwater sites, enterococci at coastal sites and faecal coliforms at coastal shellfish gathering sites. At freshwater sites assessments of algae as well as toxic cyanobacteria were undertaken.

Of the 61 coastal swimming spots monitored 39 were graded ‘good’ to ‘very good ‘ meaning they are safe for swimming most of the time. Of the 24 river sites seven were graded ‘good’ or ‘very good’. However, these river grades are heavily influenced by wet weather sampling results and when the grades are based on ‘dry weather’ conditions this number increases to 17.

“What this shows is that although our region’s overall water quality is generally very good we need to be mindful of where we swim, particularly in rivers during and after rain events. In rural areas there is a risk of faecal contamination from farm runoff, while in urban areas overflows of sewage into stormwater drains can spoil the water for up to 48 hours after rain,” says Regional Council senior environmental scientist, Summer Greenfield.

The grades are based on five years of water quality monitoring data and the most likely sources of faecal contamination for each site. They essentially provide guidance about the potential health risk associated with swimming at a particular site.

There are other potential risks at swimming sites in addition to contamination by bacteria, such as the presence of toxic algae, or high flows in rivers that present a safety hazard.

Having a good understanding of what influences the site where you like to swim can help you to choose when and where it is best to swim without risking getting sick”, says Medical Officer of Health, Dr Jill McKenzie.

Five coastal sites have been graded ‘poor’ meaning that they are not always suitable for swimming – even during dry weather. These sites are South Beach at Plimmerton, Porirua Harbour at Rowing Club, Titahi Bay at South Beach Access Road, Owhiro Bay and Rona Bay at Cliff Bishop Park. These sites, together with two freshwater sites – Hutt River at Melling Bridge and Wainuiomata River at Richard Prouse Park – which have poor ‘dry weather’ grades, were investigated over the summer to help identify sources of faecal contamination. Investigations at these sites will continue over the 2013/14 summer season.

The Greater Wellington Regional Council has included a list of current beach grades and faecal contamination risks on its website.

The On the beaches Report is available at www.gw.govt.nz/envreports.

To find out the Suitability for Recreation Grade for your local swimming site, check out www.gw.govt.nz/beachgrades

ENDS

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