High E coli levels in Southland rivers
There’s a high risk of getting sick from swimming in Southland waterways, scientists have warned.
Environment Southland freshwater and marine science leader Nick Ward yesterday said high levels of E coli found at seven different testing sites in Southland waterways meant there was a high risk of people getting sick in them.
Those sites were the Aparima River at Thornbury, Oreti River at Wallacetown, Waikaia River at Waikaia, Mataura River at Riverside, Mataura River at Gore, Oreti River at Winton Bridge, and Waiau River at Tuatapere.
E coli is a type of bacteria found in the intestines of animals and humans. It is most commonly spread in the water through fecal material.
‘‘High risk’’ was classified as more than 550 E coli cultures in a 100ml sample of freshwater.
‘‘Generally the lakes are in a very good state, but the freshwater sites are at high risk,’’ he said.
‘‘We have had elevated risk at freshwater sites over the past few years.
‘‘There’s a lot of people out there who are concerned. We need to know where this is coming from.’’
Ward said E coli — which could cause stomach flu, urinary tract infections, and neonatal meningitis — could come from a variety of sources. These included septic tanks, cow or sheep effluent, and waterfowl.
From December to March, the water at the seven sites was tested for E coli every week.
Ward said the high levels of E coli were not new.
‘‘We’ve had elevated
risk
at freshwater sites over the past few years.’’
Southland District Mayor Gary Tong said he was also concerned.
‘‘We need to tidy up our act. The E coli levels are of high concern, because they make everyone sick.’’
Stopping untreated stormwater or water from wells going directly into waterways was one way to help reduce the problem, Tong said.
‘‘We need to look at stormwater going into our waterways, as well as wells from areas of heavy metal extraction.’’
Under Environment Southland’s Recreational Waters and Human Health programme, $150,000 was being spent to identify sources of E coli and other microbiological contamination of recreational waterways at sites across Southland.
The programme was also receiving matching funds from the Institute of Environmental Science and Research.
Ward said even with high E coli levels, saying a waterway was safe or not to swim in wasn’t an easy question.
‘‘You can’t ever really say it’s safe, yes or no,’’ he said.
Weather could also risk.
Rain after a long period of dry weather could also increase risk, Ward said.
He said if water was murky or dark, it was best to avoid swimming in it.
Environment Southland’s 2015 Recreational Bathing Survey found poor water quality was the main reason people chose not to participate in water-based activities.
The survey, which attracted 197 responses last summer, found 77 per cent of Southlanders spent 8 to 14 days participating in watersports during summer.
increase