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Water quality monitoring, Whananaki. The Northland Regional Council has been monitoring bacterial levels at popular swimming spots over summer for the past decade.
Sophie Tweddle, the Council’s Environmental Monitoring Officer – State of the Environment (Reporting), says this year’s programme began on November 30 and will run until the end of March.
“The programme monitors levels of bacteria in the water at beaches, lakes and rivers that are most frequently used for contact recreation, such as swimming or water sports.”
She says hundreds of samples will be taken from 63 coastal and 21 freshwater sites this year. To allow people to make informed decisions about where it’s best to swim results will be posted every Friday from December 04 on the Council’s website at: www.nrc.govt.nz/swimming
Samples will be given one of three grades depending on the number of bacteria they contain:
• Green (safe to swim)
• Amber (elevated levels of bacteria)
• Red (unsafe for swimming).
As well as being posted on the Council’s website, results will also be forwarded weekly to District Councils and the Northland District Health Board.
Ms Tweddle says the District Health Board (DHB) and District Councils are also informed of any results showing elevated bacterial levels within 24 hours.
“It then becomes the responsibility of the DHB and the region’s three District Councils to take action. This can include further site investigations to establish the source of contamination, public warnings not to swim or gather shellfish or erection of permanent warning signs at the worst sites.”
Ms Tweddle says Northland is fortunate to have a large number of beautiful beaches, lakes and rivers, with the majority safe for swimming most of the time.
“However, due to the hilly nature of the region and the high amount of rainfall we receive, it is common for sites to become contaminated by run-off from the land for several days after heavy rainfall.”
She says there are also a few sites in Northland which are consistently unsafe for swimming due to high levels of bacterial contamination.
“These sites are affected by more persistent sources of pollution, such as leaking septic tanks or faeces from wild animals and stock. “
She says the Regional Council is currently investigating all ‘problem sites’ to try and isolate the source of contamination.
“Once the source is known, where possible work can be undertaken to try and improve the water quality. In the interim, most of these sites have permanent signs warning people against swimming or gathering shellfish.”
Ms Tweddle says people unsure about the water quality in their favourite area should remember the following:
• DON”T swim if there are warning signs indicating water is unsafe
• AVOID swimming for two to three days after heavy rain
• DON”T swim if water looks dirty/murky, smells or it has scum on the surface;
• BE AWARE of potential sources of contamination nearby or upstream.