Cows foul Patea River
A popular river swimming hole in Taranaki, which has recorded excessive levels of bacteria 23 times over the past three years has been closed.
The King Edward Park site on the Patea River is monitored twice monthly by the Taranaki Regional Council (TRC) and people have been advised not to swim or come in contact with the water, which has been contaminated by dairy cows and bird droppings.
Since December 4, E.coli readings by TRC staff at the site have exceeded the acceptable level six times.
On January 15 the water hole, which is in the Stratford urban area and regularly used by swimmers and dogs to cool off, reached 1050 parts of E.coli per 100 millilitres of water.
Then on February 1 it recorded 1300 parts/100ml - nearly three times the acceptable level of 550 parts/100ml.
Those results are the highest E.coli readings taken at the site in the last three years. The four other readings ranged from 579 parts/100ml to 1200 parts/100ml.
There have been 23 E.coli warnings at King Edward Park since February 2015.
TRC environment quality director Gary Bedford said the main contamination in the river, which ran through both rural and urban areas, was from dairy cows and bird droppings.
Bedford said staff had carried out further sampling at King Edward Park in January to confirm the levels in the initial findings, as well as source testing using DNA analysis techniques to find out where the pollution came from.
There was no human waste involved, he said.
But it is difficult to tell how long the contamination has been lingering because bad weather prevented the King Edward Park site, as well some other freshwater sites, from being sampled between December 7 and January 10.
‘‘The weather and tide constraints mean that sampling is carried out irregularly, though usually sampling occurs at least once a fortnight.
‘‘It is not only a matter of whether it is raining at the time, but whether freshwater flows could have been affected by rain falling any time during the previous three days.’’
Council resource management director Fred McLay said no prosecutions have resulted from excessive E.coli bacteria levels since 2015 at King Edward Park.
Any decision on whether any enforcement action would result would depend on the outcome of the investigation of farms in the catchment, Bedford said.
The regional council can issue an ‘instant fine’ between $300 to $1000, and take prosecution action through the Environment Court where recent penalties have ranged between $30,000 and $60,000.
Taranaki District Health Board medical officer of health Dr Jonathan Jarman said there was no obvious link between campylobacter notifications, which were slightly higher than normal in January, and swimming in Taranaki rivers.
Jarman said campylobacter was found in rivers with high E.coli and could cause diarrhoea, stomach pains and fever.
Studies showed when E.coli river levels get over 550 per 100ml there was a significant risk of campylobacter infection in one in 20 swimmers, he said.
People should see a doctor, or phone Healthline 0800 611 116 if the symptoms are severe, or don’t improve. You can also check whether a spot is safe to swim at https://www.lawa.org.nz/