Annual report 2006-2007 - Taranaki Regional Council
Annual report 2006-2007 - Taranaki Regional Council Annual report 2006-2007 - Taranaki Regional Council
3. Taranaki Galvanizers 3.1 Process description 38 The galvanising plant of Taranaki Galvanizers is situated at the corner of State Highway 3 and Monmouth Road, about 1 km north of Stratford. The plant was owned and operated by Union Galvanizers 1995 Limited until September 1998, at which time that company ceased operating. The plant remained idle until May 1999, when Taranaki Galvanizers (2003) Ltd took it over. During the reported period ownership changed once again, to Taranaki Galvanizers Limited. A hot-dip galvanising process is used. Under Union Galvanizers, operations consisted of stripping/degreasing steel articles in hot sodium hydroxide/water, a water rinse, a cold hydrochloric acid wash, a water rinse, pre-fluxing with zinc ammonium chloride, then hot-dipping in molten zinc. There is a separate galvanising stripping tank containing hydrochloric acid/water for articles that have previously been galvanised. The galvanising process employed by Taranaki Galvanizers is essentially the same as before. Minor changes have been made to improve product quality such as greater heating of the caustic degrease solution (with gas). Particular care is taken to ensure that flux solution dries on articles before they are dipped into the zinc kettle. This minimises fume generation and sputtering. In the 2003-2004 monitoring period the Company switched from the hosing of articles after caustic and acid treatment, to using a rinse tank. This resulted in a decrease in the volumes going to the trade waste tanks. Both dilute and strong liquid process wastes are produced. These are treated and disposed of separately. Dilute wastes from rinsing of articles in the galvanising process, condensation in steam-jacketed vessels, and floor washing are collected in a series of concrete tanks set within a concrete bunded area. The stormwater collected inside the bund is also pumped into the tanks. The tanks are used to pH neutralise and settle the wastewaters. The treated wastewater is then transported by road tanker from the galvanising plant to Stratford oxidation ponds after testing for zinc and pH under the supervision of the Stratford District Council. Site stormwater discharges to an unnamed tributary of the Kahouri Stream. Stormwater from the roof catchment is stored and utilised as process makeup, and is not discharged under the stormwater discharge permit unless this tank overflows. Strong wastes (comprising spent caustic cleaning and acid pickling liquors) are rarely stored on site. Plastic tanks situated in a bunded area lined with acid/caustic resistant resin are utilised entirely for emergency storage and have not been required for this purpose since 1995. The Kahouri Stream tributary originally began in the area where the galvanising site is situated and is now culverted from its origin to where it appears on the other side of SH3. The tributary downstream of the galvanising plant has been monitored regularly since it was discovered that spent acid containing a high concentration of zinc was disposed of in a bore on the galvanising plant site in mid-1987. Zinc leached through the ground and appeared in the drain, which runs under the galvanising
39 plant site from Monmouth Road. The then Regional Water Board decided to monitor the drain regularly and only take action if danger to biota of the Kahouri Stream was imminent, rather than dig the area up and risk the release of a large amount of zinc into the Kahouri system. The zinc concentration in the drain appeared to be decreasing exponentially. Figure 12 Taranaki Galvanizers site layout 3.2 Resource consents 3.2.1 Water discharge permit Section 15(1)(a) of the Resource Management Act stipulates that no person may discharge any contaminant into water, unless the activity is expressly allowed for by a resource consent or a rule in a regional plan, or by national regulations. Taranaki Galvanisers holds water discharge permit 4657 to cover discharge up to 260 litres per second of stormwater from a galvanising plant premises to an unnamed tributary of the Kahouri Stream. This permit was issued by the Taranaki Regional Council on 20 June 1995 under Section 87(e) of the Resource Management Act. It expires on 1 June 2010. Special conditions 1 and 2 specify contaminants and limits for the discharge effluent. Special condition 3 requires a stormwater management plan to be submitted to the Council, detailing measures to be minimise contamination of stormwater during spillages.
- Page 1: Kahouri Stream Monitoring Programme
- Page 4: Six complaints, which were logged a
- Page 7 and 8: ii 2.7 Recommendations 37 3. Tarana
- Page 9 and 10: iv 6.6.4 Recommendations from the 2
- Page 11 and 12: vi List of tables Table 1 Resource
- Page 13: Figure 6 Biological oxygen demand (
- Page 16 and 17: Section 11 presents recommendations
- Page 18 and 19: 1.2.1 Other resource consents A tot
- Page 20 and 21: Figure 1 Biological and chemical mo
- Page 22 and 23: 2. Taranaki Abattoir Co (1992) Limi
- Page 24 and 25: 10 Waste liquor and floor washings
- Page 26 and 27: 2.2.2 Water discharge permit 12 Sec
- Page 28 and 29: 24 March 2005, under Section 87(e)
- Page 30 and 31: 16 plant staff were made aware of t
- Page 32 and 33: 18 inspection, staff also outlined
- Page 34 and 35: Dissolved oxygen (g/m 3 ) 35 30 25
- Page 36 and 37: Dissolved Reactive Phosphorus (g/m3
- Page 38 and 39: 24 In comparing the results (upstre
- Page 40 and 41: 26 Biological survey The Council’
- Page 42 and 43: SQMCIs Value 7 6 5 4 3 2 1 0 A C E
- Page 44 and 45: 2.6 Discussion 2.6.1 Discussion of
- Page 46 and 47: Table 7 Summary of performance for
- Page 48 and 49: 34 Condition requirement Means of m
- Page 50 and 51: 36 1. THAT monitoring of air emissi
- Page 54 and 55: Special condition 4 defines the mix
- Page 56 and 57: 42 underneath the galvanising plant
- Page 58 and 59: NH 4 -N (g/m 3 ) 44 Ammoniacal nitr
- Page 60 and 61: 3.4.2 Air 46 Air monitoring in the
- Page 62 and 63: 48 Table 14 Summary of performance
- Page 64 and 65: 4. Egmont Tanneries Limited 4.1 Pro
- Page 66 and 67: permit was issued by the Taranaki R
- Page 68 and 69: 54 An additional inspection was und
- Page 70 and 71: 56 Table 16 Results of summer low-f
- Page 72 and 73: 58 In the 2006-2007 year, there was
- Page 74 and 75: Table 19 Summary of performance for
- Page 76 and 77: 62 In the case of Egmont Tanneries,
- Page 78 and 79: 5.3 Monitoring programme The monito
- Page 80 and 81: 66 Water chemistry The chemical wat
- Page 82 and 83: Table 22 Summary of performance for
- Page 84 and 85: 6. Contact Energy Limited (closed p
- Page 86 and 87: 72 not suggest that discharges from
- Page 88 and 89: 74 7. Contact Energy Limited (CCPS)
- Page 90 and 91: 7.3.2 Biomonitoring surveys 76 One
- Page 92 and 93: 78 Condition requirement Means of m
- Page 94 and 95: 8. Fletcher Concrete & Infrastructu
- Page 96 and 97: 8.3.2 Chemical sampling 82 The Tara
- Page 98 and 99: 84 The stream at this site had a cl
- Page 100 and 101: 8.6.5 Alterations to monitoring pro
39<br />
plant site from Monmouth Road. The then <strong>Regional</strong> Water Board decided to monitor<br />
the drain regularly and only take action if danger to biota of the Kahouri Stream was<br />
imminent, rather than dig the area up and risk the release of a large amount of zinc<br />
into the Kahouri system. The zinc concentration in the drain appeared to be<br />
decreasing exponentially.<br />
Figure 12 <strong>Taranaki</strong> Galvanizers site layout<br />
3.2 Resource consents<br />
3.2.1 Water discharge permit<br />
Section 15(1)(a) of the Resource Management Act stipulates that no person may<br />
discharge any contaminant into water, unless the activity is expressly allowed for by<br />
a resource consent or a rule in a regional plan, or by national regulations.<br />
<strong>Taranaki</strong> Galvanisers holds water discharge permit 4657 to cover discharge up to 260<br />
litres per second of stormwater from a galvanising plant premises to an unnamed<br />
tributary of the Kahouri Stream. This permit was issued by the <strong>Taranaki</strong> <strong>Regional</strong><br />
<strong>Council</strong> on 20 June 1995 under Section 87(e) of the Resource Management Act. It<br />
expires on 1 June 2010.<br />
Special conditions 1 and 2 specify contaminants and limits for the discharge effluent.<br />
Special condition 3 requires a stormwater management plan to be submitted to the<br />
<strong>Council</strong>, detailing measures to be minimise contamination of stormwater during<br />
spillages.
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