Annual report 2006-2007 - Taranaki Regional Council

Annual report 2006-2007 - Taranaki Regional Council Annual report 2006-2007 - Taranaki Regional Council

22.02.2013 Views

74 7. Contact Energy Limited (CCPS) 7.1 Process description Contact Energy Ltd (previously Stratford Power Limited) holds resource consents to provide for the operation of a 354MW combined cycle power station (CCPS) that is situated on the northern bank of the Kahouri Stream, off State Highway 43, 2 km east of Stratford. The plant was formally commissioned on 6 July 1998. Five of those consents relate to activities in the Kahouri Stream catchment, being discharge of stormwater, emplacement of structures (3), and disposal of treated sewage by land soakage. Most of the resource consent monitoring associated with the combined cycle plant and reported on by Council, is carried out under a separate and comprehensive programme specific to that plant. Monitoring associated with activities that may affect the Kahouri Stream are detailed in this report. The drainage system for the station is constructed so that all stormwater from process and potentially contaminated areas drains to the wastewater treatment system. The treated wastewater is discharged to the Patea River, not to the Kahouri Stream. Stormwater is collected in a storage basin that is lined with rubber. For most of the time, the stormwater is pumped to the raw water holding pond for use in the plant. At times of heavy or prolonged rainfall, the stormwater pond overflows to the flooding Kahouri Stream. Occasionally, some of the contents of the raw water pond, comprising water drawn from the Patea River, have been pumped via the stormwater pond to the Kahouri Stream in an effort to reduce the amount of algae in the raw water pond. 7.2 Resource consents Contact Energy holds several consents in relation to the operation of a combinedcycle power station. Five of those consents relate to activities in the Kahouri catchment that potentially may have effects on the results of monitoring of other industry under the Kahouri Stream monitoring programme. The remaining consents held by Contact Energy relate to abstraction from the Patea River, discharge of treated wastewater to the Patea River and discharge of emissions to air. Monitoring in respect of these latter described consents is reported on separately by the Council. 7.2.1 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. Contact Energy Limited holds water discharge permit 4459 to discharge stormwater from a combined cycle power station site, including stormwater and sediment from construction activities associated with the proposed expansion of the site, into an

75 unnamed tributary of the Piakau Stream and into the Kahouri Stream. This permit was issued by the Taranaki Regional Council on 25 May 1994 under Section 87(e) of the Resource Management Act. It expires on 1 June 2028. Special conditions 1 and 3 define discharge contaminant limits and the effects that shall not be observed in the receiving water below a 5 metre mixing zone. Special condition 2 requires that the consent holder provide a contingency plan. Special condition 4 defines the lapse period if the consent is not exercised and condition 5 is a review condition. The permit is attached to this report in Appendix I. 7.2.2 Discharges of wastes to land Sections 15(1)(b) and (d) of the Resource Management Act stipulate that no person may discharge any contaminant onto land if it may then enter water, or from any industrial or trade premises onto land under any circumstances, unless the activity is expressly allowed for by a resource consent, a rule in a regional plan, or by national regulations. Contact Energy Limited holds discharge permit 5063 to cover the discharge of domestic septic tank effluent through a soakage field onto and into land in the vicinity of the Kahouri Stream. This permit was issued by the Taranaki Regional Council on 16 December 1997 under Section 87(e) of the Resource Management Act. It is due to expire on 1 June 2028. Special condition 1 requires the septic tank and field soakage effluent treatment system to be installed according to plans submitted with the application. Special condition 2 states that the discharge shall not enter a surface water body. Special condition 3 is a review condition. The permit is attached to this report in Appendix I. 7.3 Monitoring programme The monitoring programme for Contact Energy Ltd consisted of two primary components in addition to programme liaison and management. 7.3.1 Site inspections The Contact site was visited four times during the monitoring period. With regard to consents for the discharge to stormwater and septic tank discharges, the main points of interest were plant processes with potential or actual discharges to receiving watercourses. The neighbourhood was surveyed for environmental effects.

74<br />

7. Contact Energy Limited (CCPS)<br />

7.1 Process description<br />

Contact Energy Ltd (previously Stratford Power Limited) holds resource consents to<br />

provide for the operation of a 354MW combined cycle power station (CCPS) that is<br />

situated on the northern bank of the Kahouri Stream, off State Highway 43, 2 km east<br />

of Stratford. The plant was formally commissioned on 6 July 1998.<br />

Five of those consents relate to activities in the Kahouri Stream catchment, being<br />

discharge of stormwater, emplacement of structures (3), and disposal of treated<br />

sewage by land soakage.<br />

Most of the resource consent monitoring associated with the combined cycle plant<br />

and <strong>report</strong>ed on by <strong>Council</strong>, is carried out under a separate and comprehensive<br />

programme specific to that plant. Monitoring associated with activities that may<br />

affect the Kahouri Stream are detailed in this <strong>report</strong>.<br />

The drainage system for the station is constructed so that all stormwater from<br />

process and potentially contaminated areas drains to the wastewater treatment<br />

system. The treated wastewater is discharged to the Patea River, not to the Kahouri<br />

Stream.<br />

Stormwater is collected in a storage basin that is lined with rubber. For most of the<br />

time, the stormwater is pumped to the raw water holding pond for use in the plant.<br />

At times of heavy or prolonged rainfall, the stormwater pond overflows to the<br />

flooding Kahouri Stream.<br />

Occasionally, some of the contents of the raw water pond, comprising water drawn<br />

from the Patea River, have been pumped via the stormwater pond to the Kahouri<br />

Stream in an effort to reduce the amount of algae in the raw water pond.<br />

7.2 Resource consents<br />

Contact Energy holds several consents in relation to the operation of a combinedcycle<br />

power station. Five of those consents relate to activities in the Kahouri<br />

catchment that potentially may have effects on the results of monitoring of other<br />

industry under the Kahouri Stream monitoring programme. The remaining consents<br />

held by Contact Energy relate to abstraction from the Patea River, discharge of<br />

treated wastewater to the Patea River and discharge of emissions to air. Monitoring<br />

in respect of these latter described consents is <strong>report</strong>ed on separately by the <strong>Council</strong>.<br />

7.2.1 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 />

Contact Energy Limited holds water discharge permit 4459 to discharge stormwater<br />

from a combined cycle power station site, including stormwater and sediment from<br />

construction activities associated with the proposed expansion of the site, into an

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