How Whanganui's Tasman Tanning plans to improve environmental record

Tasman Tanning is continuing to work on improving its trade waste. Photo / Bevan Conley

Whanganui's Tasman Tanning expects to drop its effluent waste and chromium levels to significantly below the district council's allowable limits by the end of the year, chief executive Neville Dyer says.

The tannery breached its wastewater consents 570 times in the last year, it was reported in January.

Tasman Tanning contributes only 5 per cent of the water treated by the Whanganui wastewater treatment plant - but 25 per cent of the solids.

The tannery's contribution of chromium III to the city's wastewater does concern the council. It is a toxic heavy metal and the council's limit of 5mg/litre was breached 200 times during 2020, RNZ said.

Tasman Tanning had been in a two-year battle to reduce the chromium. The council had been monitoring this, and graphs showed the level falling.

Tasman installed a $1.8 million chromium extraction plant in 2018, but it has had teething problems.

The company was making a further investment of nearly $1.5m to extend its treatment plant to capture not only chromium but other waste such as fat and sulphides much more thoroughly, Dyer said.

Its chromium output should also be reduced by a new contract to process 1.8 million sheepskins from Silver Fern Farms meatworks in Takapau and Waitotara. Most of them will be semi-processed for export rather than tanned, and tanning them will not require chromium.

The new contract is not an expansion of the plant. Instead it replaces another contract.

The council's wastewater limits were not providing the only pressure on the company. Tasman Tanning was working toward international acceditation with the international Leather Working Group. It wanted to achieve silver medal status, and had to reduce its environmental impact to achieve that.

Its new dyehouse equipment was costing $2m, and would reduce water use and waste by about 15 per cent, Dyer said.

Tasman's Timaru plant, bought in December 2019, is also to construct a new waste treatment system.