Annual report 2006-2007 - Taranaki Regional Council

3.4.2 Air
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Air monitoring in the 2006-2007 monitoring period comprised of visual inspections.
Deposition gauging is carried out on a biennial basis and was not conducted during
the monitoring year under review. This is to be conducted in the 2007-2008
monitoring period.
At the time of both inspections (14 December 2006 and 28 June 2007) there were no
off-site odours. Visible aerial emissions were observed during the June 2007
inspection but did not cause odours offsite.
3.5 Register of incidents
The Taranaki Regional Council operates and maintains a register of all complaints or
reported and discovered excursions from acceptable limits and practices, including
non-compliance with consents, which may damage the environment. The register
(‘unauthorised incident register’) includes events where the company concerned has
itself notified the Council. The register contains details of any investigation and
corrective action taken.
Incidents may be alleged to be associated with a particular site. If there is an issue of
legal liability, the Council must be able to prove by investigation that the identified
company is indeed the source of the incident, (or that the allegation cannot be
proven).
In the 2006-2007 year, there were no incidents recorded by the Council that were
associated with Taranaki Galvanizers.
3.6 Discussion
3.6.1 Discussion of plant performance
During the monitoring year under review, the performance of the Taranaki
Galvanizers site has been good.
Fumes can be generated during the galvanising process on occasions. It is recognised
that working conditions within the building may necessitate ventilation requiring
that doors be kept open, and that the exhausting of fumes has not been demonstrated
to lead to significant off-site environmental effects. The incident of fume generation
has reduced since the plant was taken over by Taranaki Galvanizers.
The stormwater catchment was generally kept clear of contaminants throughout the
year, and wastewater was adequately bunded and managed well.
3.6.2 Environmental effects of exercise of consents
Stormwater discharges from the site were monitored during the year and effects on
the unnamed tributary of the Kahouri Stream assessed. Water chemistry monitoring
indicated that elevated zinc levels were continuing to occur in the stormwater (and
leachate) discharge from the galvanising site, as a result of historical disposal of
spent acid to a bore on the property. However, trends in zinc levels over time
indicate that concentrations of zinc are continuing to drop, as the pH of the discharge