Increasing log traffic and poor stormwater management have been blamed for Port Taranaki flunking its latest environmental monitoring report.
One incident in March this year caused the swim stage of the New Zealand Secondary Schools Triathlon to be cancelled after E coli and enterococci bacteria levels were discovered many hundred times over allowable limits.
A Taranaki Regional Council port industries environmental report for 2018-2019 concluded that it was unclear whether the contamination - which started in a stormwater pipe clogged with stock feed - had the potential to cause illness or not.
The report said no trace of human contamination was found, but bird and rodent faeces could have contributed to high bacteria counts and potential health risks.
During routine testing on 13, 20 and 25 March enterococci counts of 9100, 3000 and 480cfu/100 ml were recorded respectively. The action level for enterococci is two consecutive measures of 280 cfu/100 ml.
A Weetabix Tryathon event involving hundreds of Taranaki school children went ahead on 26 March after a New Plymouth lab returned three results below the action level.
But by 29 March the Taranaki Medical Officer of Health advised the secondary school competitors to stay out of the water after a string of results of 5000cfu/100ml or more.
The International Triathlon Union (ITU) World Cup went ahead on 31 March after the all-clear was given, although the swim stage was in the balance.
Decline in environmental performance
The council report said stormwater controls at Port Taranaki had not kept pace with its expansion in particular to accommodate logs.
There were two noncompliant stormwater discharges during the period and two unauthorised incidents which resulted in enforcement action - including a significant diesel spill - which, the report, said represented a decline in environmental performance.
The report said after finding "faecal indicator bacteria counts were extremely high by comparison with typical results" daily testing was started.
By 29 March investigators had identified a stormwater pipe at the eastern corner of Ngāmotu Beach as the likely culprit.
Enterococci counts in the area of the pipe peaked at 451,600,000cfu/100ml, while E coli counts reached 7100/100ml when 550/100ml is the action level.
They found a large amount of grain feed lying at the base of the pipe which became inundated with seawater at high tide, distributing the contamination.
"Upon further investigation of the adjacent reclamation it became evident that the source of contamination was likely the soy meal that was being stored on-site," the report said.
The soy meal most likely served as the growth medium allowing the bacteria to proliferate, it said.
"The actual health risk posed by this contamination event remains unclear," the report said.
"No trace of human contamination was found, but the possibility remains that bird and rodent faeces contributed to the high faecal indicator bacteria counts."
The report concluded it was impossible to infer whether the contamination had the potential to cause illness or not.
Infringement notices issued
Port Taranaki and Regal Haulage were both issued with infringement notices in response to this incident and the port has now included this part of the stormwater network in its inspection and cleaning schedule.
Port Taranaki was also issued an abatement notice and later an infringement notice for noncompliant stormwater discharges in April and June 2019 respectively.
These were due to suspended solids blamed on material from logs.
Port Taranaki is the only deepwater port on the west coast of the North Island and log exports have grown four times since 2014-2015 when 209,100 million cubic metres was moved to 2018-2019 when 876, 263 million cubic metres went across its wharves.
The regional council report said stormwater upgrades had not kept pace with the number of logs being handled at Port Taranaki.
"As this industry has grown, more space at the port has been repurposed for log storage. These changes have happened without the appropriate stormwater controls in place, as demonstrated by the discharge monitoring which recorded two noncompliances."
The report acknowledged Port Taranaki was now making significant upgrades to its stormwater network.
The port also had a significant hydrocarbon spill in January 2019 when 500 to 600 litres of diesel was spilt into the Hongihongi Stream which drains at Ngāmotu Beach.
Although 80 percent of the spill was recovered, a sheen could be seen across the harbour and the beach was closed for 24 hours.
The port was issued with an abatement and infringement notice for this spill.
The monitoring report concluded Port Taranaki demonstrated an overall level of environmental performance which required improvement.
It recommended the monitoring regime at Port Taranaki remain the same apart from adding the offending stormwater pipe to its regular test sites.
It warns however should there be any more environmental or administrative performance issues during 2018-2019 monitoring may be adjusted.
Port Taranaki chief executive Guy Roper said he regretted the company's performance.
"We work within the natural environment and understand the responsibility we have to look after the environment and harbour.
"In the past year there have been instances where our environmental performance has not been up to the high standard we expect."
Mr Roper said Port Taranaki had upgraded its stormwater system, tightened environmental monitoring and storage protocols, and employed a fulltime environmental manager and site management coordinator as it worked to improve its environmental performance.
For the 2018-19 financial year, Port Taranaki recorded a 26.9 percent increase in its log trade, Mr Roper said.
To accommodate this growing trade, Port Taranaki had removed the cold store on Blyde Wharf, upgraded the stormwater system through installing new screening units, and sealed the area.
"We had a big increase in log trade during the year and, unfortunately, it took us longer than desirable to upgrade our stormwater system.
"However, we are confident the work we have now done on Blyde Wharf to upgrade and improve the stormwater system will meet the needs of our log business in the future," Mr Roper said.
"The whole nature of our industrial port activity around the environment has been strengthened and we are also looking to our tenants to strengthen their environmental management procedures."