Annual report 2006-2007 - Taranaki Regional Council

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Dissolved Reactive Phosphorus (g/m3) 22 Dissolved reactive phosphorus in discharge from Taranaki Abattoirs 25 20 15 10 5 0 Feb-89 Feb-91 Feb-93 Feb-95 Feb-97 Feb-99 Feb-01 Feb-03 Feb-05 Feb-07 Figure 9 Dissolved reactive phosphorus concentrations in the discharge from the aerobic pond at Taranaki Abattoirs. Clear diamonds indicate 2006-2007 monitoring results 2.4.2.2 Results of receiving environment monitoring Water chemistry The chemical water quality survey for the summer low-flow period was performed on 18 April 2007 during fine weather. The daily mean flow at the nearest river flow recorder, on the Patea River downstream at Skinner Road, was 780 litres per second2, and therefore it is thought that Kahouri Stream was flowing at approximately mean annual low flow. The results for the 2007 survey are presented in Table 4. The survey was conducted during stable flows, with only a number small flushes occurring in the three months previous. The last significant fresh (greater than 3 times median) had occurred more than three months prior to this survey. Two chemical monitoring sites are located in the receiving waters near Taranaki Abattoirs. They are located in the Kahouri Stream itself, one just upstream of State Highway 3, the other about 50 metres below the confluence with the tributary which receives the discharge from the waste treatment ponds (Figure 1). Consent conditions 1 and 2 in resource consent 0108 state the following water quality limits in the receiving Kahouri Stream 50 m downstream of the confluence with the tributary receiving the wastewater discharge from Taranaki Abattoirs: Special condition 1 BOD5 shall not raise concentration by more than 1 g/m 3 Special condition 2 NH3 upper limit of 0.025 g/m 3 The ambient BOD5 of the Kahouri Stream upstream of the abattoir discharge was at the detection limit of 0.5 g/m 3. The BOD5 concentration 50 m downstream of the tributary that receives the Taranaki Abattoir wastewater discharge was 5.0 g/m 3, an increase from the background level of 4.5 g/m 3 (Table 4). Therefore, compliance in 2 The annual median flow at this point is about 3,133 litres per second and the mean annual low flow is approximately 783 litres per second.
23 respect of special condition 1 of consent 0108 was not achieved at the time of this survey. This is the third consecutive year that this non-compliance has occurred. The BOD5 in the discharge (180 g/m 3) during this low flow survey was relatively high compared to previous years, and coupled with a high chemical oxygen demand suggested that the aerobic pond was not performing well. Considering it appears the Kahouri Stream had recorded lower flows prior to this water quality survey, it is likely that greater increases in the BOD5 may have occurred in the Kahouri Stream downstream of the abattoir discharge during March and early April 2007. Further, at BOD5 concentrations greater than 2 g/m 3, there may be some potential for undesirable heterotrophic growths to bloom in the stream. No such growths were detected in the biological monitoring conducted on 17 April 2007 (refer to biological section below). The un-ionised ammonia concentration 50 m downstream of the tributary was 0.01155 g/m 3, compared to the consent limit of 0.025 g/m 3. Compliance in respect of special condition 2 of consent 0108 was therefore achieved at this time. Un-ionised ammonia is the most toxic form of ammonia, and at these concentrations, is unlikely to cause significant adverse effects on the biological communities of the Kahouri Stream. While this concentration of unionised ammonia may not be expected to cause significant adverse effects it still reflects an increase of more than 100 times the background figure recorded upstream. Furthermore, the ammoniacal nitrogen (NH4) increased significantly to 1.87 g/m 3, being 155 times higher downstream of the tributary that receives the abattoir wastewater discharge, compared to levels upstream. Compared to the ANZECC Water Quality guidelines (ANZECC 2000) which provide limits to prevent nuisance growths of algae, this is extremely high (when compared with the limit for slightly disturbed systems in upland rivers). The recommended limit for ammoniacal nitrogen is 0.01 g/m 3. In the Kahouri Stream at Flint Road, this concentration had dropped somewhat, but remained high (0.226 g/m 3), thus indicating ammonia concentrations appear to fall significantly by this point 3 km downstream (TRC site code KHI000400). Dissolved reactive phosphorus was raised from 0.094 to 0.263 g/m 3 below the discharge. However, this had decreased slightly to 0.134 g/m 3 at the site in the Kahouri Stream at Flint Road. The ANZECC guideline for DRP in slightly disturbed systems in upland rivers is 0.009 g/m 3 (ANZECC, 2000). The previous survey had seen ammonia and phosphorus concentrations between these two sites drop to much lower concentrations, indicating that the higher concentrations seen in the discharge during this survey somewhat overloaded the assimilative ability of the Kahouri Stream. The discharge was not observed to cause any conspicuous effects upon the water of the Kahouri Stream at the downstream sampling point. The turbidity and suspended solids results did not change markedly at the Kahouri site downstream of the confluence with the tributary that carries the abattoir effluent. During the low flow survey, an additional sample was taken from the tributary into which the abattoir discharges but approximately 30 metres upstream from the abattoir’s discharge point. This provides an indicator of the background concentrations that are in the tributary prior to the discharge entering it.
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 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 52 and 53: 3. Taranaki Galvanizers 3.1 Process
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 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 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
Page 102 and 103:
88 what effects the discharge shall
Page 104 and 105:
90 Incidents may be alleged to be a
Page 106 and 107:
10. Water quality in the Kahouri ca
Page 108 and 109:
94 Most MCI scores were similar to
Page 110 and 111:
96 12. Summary of recommendations 1
Page 112 and 113:
NH3 unionised ammonia, normally exp
Page 115:
Appendix I Resource consents held b
Page 173 and 174:
To Job Manager, B Jansma From Scien
Page 175 and 176:
Figure 1 Biomonitoring sites in the
Page 177:
Table 3 Macroinvertebrate fauna of
Page 180 and 181:
MCI value 140 120 100 80 60 40 20 0
Page 182 and 183:
Site E: Kahouri Stream (KHI000400)
Page 184 and 185:
mayflies, elmid beetles, Archichaul
Page 186 and 187:
Further downstream at Flint Road, t
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Annual report 2006-2007 - Taranaki Regional Council

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