A tanning company with a history of dumping contaminants down the drain is taking on a large new contract, RNZ understands.
Tasman Tanning's plant in Whanganui was already the country's leader in breaching trade wastewater consents before it took on the new work, which is likely to increase the waste it produces.
Approximately 1.8 million animal pelts from Silver Fern Farms Takapau and Waitotara meatworks will now be processed by Tasman Tanning in Whanganui, RNZ has been told.
Previously the pelts were processed by Hastings-based Lowe Corporation, which is one of New Zealand's largest tanneries and prides itself on being an environmentally sustainable business.
Lowe Corporation owner Andy Lowe said the contract with Silver Fern Farms represented about 70 percent of his business but would end on 8 April.
Silver Fern Farm staff advised him the contract was going to Tasman Tanning, Lowe said.
An RNZ investigation revealed the Tasman Tanning plant in Whanganui clocked up 570 fat, sulphide and chromium breaches over the past year.
This meant the sludge from the city's wastewater treatment plant was so contaminated with chromium, a toxic heavy metal, it had to be stored instead of being sent to landfill.
Some of the Whanganui breaches resulted in faecal bacteria from the city's wastewater treatment plant entering the ocean.
RNZ asked Silver Fern Farms head of Communications and Sustainability Justin Courtney what due diligence had been done before the contract was awarded to Tasman Tanning and if it was aware of the company's repeated wastewater breaches.
He declined to give an interview, but did provide the following statement:
"Silver Fern Farms have had a long-standing commercial relationship with NZ Light Leathers/Tasman Tanning. As part of the relationship we have discussed their environmental improvement programme, which has shown progress toward international environmental accreditation, and has been backed with a multimillion dollar investment in additional treatment process infrastructure."
SFF fined over ammonia leak
Yesterday, Silver Fern Farms was fined $337,500 after its South Taranaki meat processing plant leaked ammonia, contaminating several kilometres of the Tawhiti Stream, which flows into the lower Tangahoe River, and killing more than 1000 fish and eels.
Tasman Tanning's breaches included more than 200 incidents where chromium was dumped.
In Whanganui, this wreaked havoc on the council's wastewater plant, killing bacteria essential to the treatment plant's operation.
Trade waste scientist Tara Okan said chromium in a waste treatment system is toxic to the good bugs, which drive the anaerobic treatment process.
Without the good bugs doing their job, untreated waste can enter the next treatment phase. The final step involves sterilisation of harmful bacteria by UV lights and is most important for public health.
If high solids material is then discharged through the UV lights, solid particles can shield harmful bacteria like E.coli and faecal coliforms from the sterilising rays and these are then discharged untreated into the environment which defeats the purpose of having a treatment process.
Series of meetings
A Whanganui District Council plant monitoring report, obtained by RNZ, states the high chromium loads resulted in a series of meetings with the customer in question in an attempt to reduce the chromium loads to the plant and improve the effluent quality.
The monitoring report shows at times there appeared to have been spikes where enterococci bacteria were discharged from the plant at three times the maximum allowable limit.
Tasman Tanning did not respond to requests for comment on the Silver Fern Farms' contract.
Previously, it admitted fault for discharges of trade waste, but also disputed the accuracy of Whanganui District Council's monitoring, saying it didn't believe it breached conditions as often as the council claimed.
As well as 205 chromium breaches, Tasman Tanning had 27 breaches for pH, 58 for oil and grease, 59 for ammonia and 211 for sulphides recorded in Whanganui.
The company said the high levels of grease and sulphides were "not much of an issue" for the Whanganui Wastewater Treatment Plant.
Tasman Tannings Timaru plant clocked up 73 breaches involving dumping too much chromium, sulphide, ammonium and zinc down the drains.
The company said a filter installed at Whanganui last year didn't work and it was spending $1 million on a new system to filter out the chromium.
It was also planning an upgrade to make processing more efficient, including recycling chemicals and effluent, and reducing water use, with the aim of gaining international environmental accreditation from the Leather Working Group.
Whanganui District Council's chief executive Kym Fell said it monitored discharges to the wastewater treatment plant daily.
"Tasman Tanning's levels of chromium discharged to the plant are higher than we would like, but have greatly reduced with the purchase of new equipment in the last two years and are heading in the right direction," he said.
When asked how the plan would cope if there was an increase in chromium discharges, he said the currently permitted levels would need to be met.
Lowe Corporation had the contract with Silver Fern Farms for nearly two decades and had invested in technology to recycle the toxic heavy metal chromium used in the tanning process, Lowe said.
Tasman Tanning treated its effluent onsite to reduce the amount of chromium it discharged but this did not work as well as it had hoped it would, and it was still discharging too much of the toxic heavy metal down the drain.
"The gut-wrenching thing for us is we thought Silver Fern was an environmentally, sustainable and conscious business," Lowe said.
The contract loss could result in a few job losses, he said. "We're still working through that."
Due to a legal loophole, neither Whanganui District Council nor Timaru District Council has been able to fine the company for its repeated breaches.
After RNZs investigation highlighted the problem, Minister of Local Government Nanaia Mahuta told Morning Report the issues would be addressed by the new water regulator, Taumata Arowai. This was likely to take at least two years.