Problems with the management of hazardous waste and poor environmental practices by Tiwai Aluminium Smelter have been in the news recently, Carl Reller, retired environmental engineer and hazardous materials expert, reports on non-compliance at Tiwai Point smelter and the weakening of standards by the Southland Regional Council.
Official Information Act requests to Environment Southland found over 85% of compliance records are missing, including a crucial independent investigatory report by Woodward-Clyde from 1992.
The earliest available records (1986) describe Clean Air and Water Rights Act “license conditions” for air quality, water discharge, and monitoring of farm animal and of pastoral herbage contamination. Reller reports that Tiwai Points:
- Landfills operated without consents from 1971 to 1996; and
- Cyanide waste-water plant operated without consents from 1971 to 1990.
The Resource Management Act 1991 shifted regulatory responsibility from the Department of Health to Southland Regional Council (now called Environment Southland). In 1994, new 12-year consents were granted to NZAS with significant changes; replacing most limits and standards with guidelines – “the exceeding of which requires further investigation or other action without constituting a non-compliance”. Eventually even many guidelines were eliminated including maximum cyanide contamination in seawater, maximum concentration of fluoride in drain-water and maximum concentration of fluoride in vegetation herbage.
Now landfill and air quality consents have no limiting conditions when monitoring for contaminates in groundwater or fluoride from:
- atmospheric deposition,
- contaminated pasture grass, or
- ambient air particulates.
A comparison of past conditions with the most recent, reveals cancellation of conditions with chronic non-compliance. Below are examples from pasture grass contamination and waste-water ocean discharges.
Examples of Monitoring, non-compliance and changes to conditions:
1. Pasture grass: fluoride contamination
Year NZAS report
1992 “exceptions being an increase in the vegetation fluoride in the area directly north of the smelter.”
1993 “increased vegetation fluoride north east of the smelter.”
Result: Environment Southland removed that consent condition.
| Condition | 1986 | 2019 |
| fluoride in forage maximum contamination | 40 mg/kg | No limit |
| Reported | 84 mg/kg | 475 mg/kg |
| Result | Non compliant |
2. Discharge to water: fluoride contamination
Year NZAS report
1986 “The material build up has now reached a stage where it is difficult to comply with the condition for the drain discharge fluoride concentration”
1993 “Problems continue with the north drain fluoride discharge.”
1994 “As with previous years the fluoride levels in the north storm water drain exceeded the permit standard.”
Result: Environment Southland removed that condition.
| Condition | 1986 | 2019 |
| fluoride in drain water maximum contamination | 10 mg/L | No limit |
| Reported | Non compliant | 31 mg/L |
| Maximums not reported (annual average 10mg/L) |
3. Discharge to water: coastal marine area cyanide contamination
Year NZAS report
1991 “high receiving water fluoride and intermittent high total cyanide concentrations occurred.”
1992 “receiving water total cyanide condition of the permit was violated”
1993 “Investigation into remediation of ground water contaminated by cathode pad leachate and diesel continued”
1994 “at the maximum allowable discharge rate there is insufficient dilution available to meet the receiving seawater conditions in the present consent.”
Result: Environment Southland removed this condition.
| Condition | 1986 | 1994 | 2019 |
| cyanide in sea water maximum contamination | 0.05 mg/L | 0.05 mg/L | No limit |
| Frequency | Every discharge | Every discharge | Annual |
| Reported | Non compliant | Non compliant | <0.01 mg/L |
| maximums not reported (monthly average 0.03 mg/L) | 0.13 mg/L |
ECO is not surprised that the Minister of Environment is stating he is still “blind on the environmental contamination” at Tiwai or that the Minister of Energy and Resources is not moving on further negotiations with Rio Tinto until they “share this critical site information or make environmental remediation commitments”.
References used:
LGOIMA 2020/063 re: Tiwai Point Aluminium Smelter. Email Reller to Thayer. 30 NOV 2020
Investigation of Leachate Movement from the Spent Cathode Storage Pad, Final Report. Woodward-Clyde. 1992
NZAS Annual report, 1986, 1991 to 1994, and 2019.
Environment Southland. NZAS consent 202196. 2003
NZAS quarterly report Q2. 1992 and 2020
RadioNZ: Govt still blind on Tiwai Pt contamination – Parker
Newshub: Toxic waste from Tiwai Point smelter: Government halts talks over lack of plan, environment commitments
Stuff: Environment Southland increasing monitoring at Tiwai smelter site