INSPECTORS REPORT ON A LICENCE APPLICATION

Transcription

1 OFFICE OF LICENSING & GUIDANCE INSPECTORS REPORT ON A LICENCE APPLICATION To: Directors From: Aoife Loughnane - Licensing Unit th Date: 20 July 2006 RE: Application for an IPPC Licence Review from Huntstown Power Company Limited, Huntstown, Finglas, Dublin 11. Licence Register P (779) Application Details Class of activity: 2.1 The operation of combustion installations with a rated thermal input equal to or greater than 50 MW. Section 87(1)b notice sent: 21/02/06 Information under Section 87(1)b received: 24/03/06 Notices under Article 17 issued: 11/05/06 Information under Article 17 received: 06/06/06, 12/06/06, 26/06/06 Submissions received: None Site visits: 09/02/06 BACKGROUND IPC Licence Reg. No. P was granted to CRH Estates Limited on 27 th October 1999 for the development of a power station at Huntstown, Finglas, Dublin 11. The site is located adjacent to a working quarry operated by CRH Estates Limited. This power station was to consist of two combined cycle gas turbines (CCGTs), and the development of the site was to take place in two stages (Phase I and II), each corresponding to the installation of one of the CCGTs. Huntstown Power Company Limited subsequently acquired this installation and became the licensee. Phase I of the development was completed and the first CCGT commenced operation in However, changes to the original proposed scale, layout and ownership arrangements for the Phase II development mean that Phase II now requires a separate IPPC licence. An application for a new, separate licence for Phase II was made on 10 th January 2006 (Reg. No. P ) and is referred to as Phase II throughout this report. In 2003, Huntstown Power Company Limited applied for a review of their licence (P ) but subsequently withdrew that application for corporate reasons and in light of the sale of part of the site for the second gas turbine (Phase II) to Viridian Power Limited. The withdrawal/abandonment of the review application was the subject of detailed discussions between Agency and licensee. Page 1 of 8

2 A request for a review of licence Reg. No. P , in order to amend it to cover Phase I only, was made on 10 th January This review application (Reg. No. P ) is referred to as Phase I throughout this report. As mentioned earlier, Phase I is owned by Huntstown Power Company Limited and operated by GenSys Power Limited. Phase II is owned by Viridian Power Limited and will be operated by GenSys Power Limited. These three companies are all wholly owned subsidiaries of Viridian Group plc. Phase I commenced open cycle gas turbine operation (by-pass of the heat recovery steam generator) in July 2002 and combined cycle operation (turbine and heat recovery steam generator operation) in November Construction of Phase II commenced in August 2005 and operation is expected to commence in Autumn The licensee has submitted a revised site plan Drawing No. A0/61825B/G/002 Rev. B which shows the distinction between the Phase I and Phase II boundaries (see Appendix A). This report deals with the environmental issues arising from the operation of the Phase I power plant. REASON FOR REVIEW The review of licence Reg. No. P is necessary for the following reasons: (i) to amend the site boundary and accommodate changes arising from the separate IPPC licence application (Reg. No. P ) for a portion of the site; (ii) to take account of proposed changes in discharges to water; and (iii) to incorporate the amendments to the licensing provisions of the Environmental Protection Agency Acts 1992 and 2003, as appropriate. ENVIRONMENTAL IMPACT STATEMENT Planning permission for the development of two CCGTs with a combined output of 600 MW e was granted on 25 th March Fingal County Council granted subsequent planning permission for the increased combined output of 740 MW e on 18 th July An EIS was required in support of the original planning application, however Fingal County Council did not require a further EIS for the subsequent planning application. The EIS submitted in support of the first planning application was assessed by the Agency as part of the assessment of licence Reg. No. P and was deemed to comply with the statutory regulations. Huntstown Power Company Ltd. submitted a planning application and EIS to Fingal County Council on the 7 th July 2006 for alterations to the development and an increase in nominal power output to 765MW. The Recommended Determination (RD) does not incorporate the increased power output for which planning permission is been sought. INTERACTION BETWEEN THE TWO SITES The Phase I plant was designed and constructed with a number of plant items, services and interconnections with sufficient capacity to meet the operational requirements of two CCGTs. Items which will remain under Phase I control, but which will serve both Phase I & II, include the gas compound, switchyard area, water treatment plant (demineralisation plant), firefighting & raw water storage tanks, distillate oil unloading station, sanitary effluent treatment system, consumable stores building and administration/control building. As the majority of the shared services remain under the control of Phase I, they form part of this licence review application and are included in the attached RD. Aqueous emissions will be dealt with as follows: Process effluent from Phase I & II will be collected separately and subject to separate treatment (neutralisation) and monitoring, prior to discharge at a common emission point D1 to the adjacent quarry drainage system. Page 2 of 8

3 Surface Water Drainage from Phase I & II will not be entirely separate; therefore the monitoring point is shared and is identified as I-SW. Grab samples may be taken from any individual stream where there is a manhole for access, including locations downstream of all oil interceptors. Sanitary Effluent from Phase I & II will be treated on-site in the existing proprietary bio-aerator and discharged to ground via a raised percolation bed. Operation, control and maintenance of the proprietary bio-aerator and percolation bed are the responsibility of Huntstown Power Company Limited. PROCESS DESCRIPTION The CCGT plant operation has been described in the Inspector s report for the current licence (Reg. No. P ). The power plant is a cycling or base load plant and could operate for 24 hours per day and 365 days per annum, depending on maintenance and despatch requirements. The plant operates on natural gas with distillate oil as a standby fuel, in the event of an interruption to the gas supply. Gas is supplied to the installation by Bord Gais Eireann and electricity is supplied to the ESB National Grid. The Phase I plant consists of a MW e gas fired CCGT. The main power generating element is a Siemens gas turbine. The exhaust gases pass through a heat recovery steam generator (HRSG) which delivers steam to a separate steam turbine. The steam is condensed in an air-cooled condenser. The plant operates under three modes: (i) combined cycle (turbine and HRSG) using natural gas; (ii) combined cycle using distillate oil; (iii) open cycle (by-pass of HRSG) using natural gas. In combined cycle mode, the HRSG integral exhaust stack is the main emission point (labelled E1 in Schedule B of the RD). Open cycle mode allows the plant to produce electricity from the gas turbine alone only in instances where there is either a planned maintenance or forced outage of the HRSG and steam turbine. In open cycle mode, the bypass stack is the emission point (labelled E2 in Schedule B of the RD). Distillate oil will be used in the event that natural gas is unavailable. Operation on distillate oil is not expected to exceed 10 days per year. On-site storage is provided for up to five days provision of distillate oil (10,000m 3 ) and demineralised water. Demineralised water is required for injection into the gas turbine to control NO x emissions when operating on distillate oil. USE OF RESOURCES The average annual usage to date of fuel, energy, mains and groundwater at the installation is shown in Table 1 below. The CCGT plant operates on natural gas as a primary fuel with distillate oil as a standby fuel. Service water is supplied from two on-site wells on a duty/back-up basis, and is treated in the raw water demineralisation plant prior to use. Groundwater is also used to supply the fire protection system. Potable water for domestic use is obtained from the Local Authority mains supply. The use of an air-cooled condenser avoids the need for large quantities of cooling water associated with conventional power plants. Table 1: Use of Resources Gas Fuel 7,013,713 Sm 3 (house load) Distillate Oil Fuel 4 m 3 (used for testing purposes) Electricity 846 MWh Mains Water 3,890 m 3 Groundwater 37,447 m 3 Page 3 of 8

4 IPPC DIRECTIVE This installation falls within the scope of Category 1.1 (Combustion installations with a rated thermal input exceeding 50 MW) of Annex I of Council Directive 96/61/EC concerning integrated pollution prevention and control. The Recommended Determination (RD) takes account of the requirements of the Directive. In particular, Condition 7 provides conditions dealing with energy, water and raw material use, reduction and efficiency on-site. Conditions 9 and 10 deal with accidents, emergency response, decommissioning and residuals management at the installation. BAT is taken to be represented by the guidance given in the IPPC Reference Document on BAT (BREF) for Large Combustion Plants (May 2005). LARGE COMBUSTION PLANT DIRECTIVE 2001/80/EC The Large Combustion Plant Directive 2001/80/EC applies to combustion plants with a rated thermal input of equal to or greater than 50 MW, irrespective of the fuel used (solid, liquid or gaseous). Under Article 2(7)(j) gas turbines licensed before 27 November 2002 are exempt from the requirements of the Directive. The current licence (Reg. No. P ) was issued on 27 th October 1999, therefore the Directive is not applicable to this installation (Phase I). Notwithstanding the above, the licensee has compared the maximum emission concentrations sought in the review application to the NO x emission limits for gas turbines, which are specified in Annex VI.B of the LCP Directive. The requested emissions of 50mg/Nm 3 during gas firing and 125 mg/nm 3 during distillate oil firing are generally consistent with the limits specified in the Annex, which specify 50 mg/nm 3 (or 75 mg/nm 3 under certain circumstances) for gas firing and 120 mg/nm 3 for distillate oil firing, at 15% O 2 reference conditions and above 70% load. EUROPEAN COMMUNITIES (CONTROL OF MAJOR ACCIDENT HAZARDS INVOLVING DANGEROUS SUBSTANCES) REGULATIONS, 2006 (S.I. NO. 74 OF 2006) The Seveso Regulations apply to establishments where dangerous substances are present in amounts equal to or exceeding certain thresholds. S.I. No. 74 of 2006 introduced lower thresholds for the qualifying quantities of petroleum products stored at a site. The licensee has identified that the installation now falls under the scope of the Seveso Regulations as a lower tier establishment, which requires compliance with Articles 6 & 7 of the Seveso Directive 96/62/EEC. The National Authority for Occupational Safety and Health (NAOSH) is the competent authority responsible for administration and enforcement of these regulations. RECOMMENDED DETERMINATION AIR This review essentially involves the removal of two stacks references from the original licence i.e., the proposed main and bypass stacks associated with the Phase II CCGT, and the inclusion of revised volumetric limits for the existing stacks. In addition, the licensee has requested an increased NO x limit of 125 mg/nm 3 during distillate oil firing, compared to the currently specified 120 mg/nm 3. The emissions of NO x are below 50 mg/nm 3 during natural gas firing. This is the emission limit value specified in the current licence, therefore there will be no change to the ELV when firing on gas. The current licence specifies a SO x limit of 120 mg/nm 3 during distillate oil firing. The RD reduces this limit to 80 mg/nm 3, based on information supplied by the licensee. The impact of atmospheric emissions from the power station was previously assessed as part of the application for the original licence. The licensee has submitted a revised air dispersion modelling assessment, which takes account of more accurate measured data from this installation, updated predicted emissions from the proposed Phase II and a newer version of Page 4 of 8

5 ISC-3 model. The model has been used to predict the ground level concentrations of NO x and SO x based on the cumulative emissions from Phase I and the proposed Phase II installations. Overall, the modelling assessment concludes that atmospheric emissions from the power stations do not impact significantly on local air quality and will not lead to an exceedence of Air Quality Standards. The RD maintains the continuous monitoring requirement for stack emissions, and requires monitoring of sulphur dioxide and dust on a biannual basis. Condition 6 limits operation of the installation on distillate oil to occasions when there is an interruption to the gas supply or when otherwise agreed by the Agency. Condition 11 requires the licensee to maintain records on-site of periods during which the plant operates in two shift mode and of any other start-up or shut-down of the gas turbine. Minor Atmospheric Emissions A 10.35m 3 capacity hydrochloric acid storage tank was installed in July 2004 to allow for bulk storage of acid. An associated scrubber unit was installed to abate breathing losses. The HCl tank is filled three times per annum. While the HCl tank is not being filled, a pump operates for 1 minute every 15 minutes. This ensures the packing in the scrubber contains 10% weight of water, which is sufficient to absorb up to 3kg of HCl vapours. The licensee states that during periods of non-filling of the main tank, and with the scrubber pumps set to operate four times per hour, there is negligible flow into the scrubber, therefore the emission concentration is trace. Minor emissions to atmosphere from the auxiliary boiler, emergency generator, safety creep relief valve at the gas compound and breathing losses from the distillate oil storage tank were assessed during the original licence application stage and are not considered significant. EMISSIONS TO SEWER: There are no emissions to sewer from the installation. EMISSIONS TO WATERS: Process effluent and surface water run-off is discharged from the site into the adjacent quarry dewatering network which drains from Huntstown Quarry in a northeasterly direction and joins the Ward River at Owens Bridge, c.6km from the installation. The Ward River discharges to the sea at Swords. The licensee has requested an increased volumetric limit of 200 m 3 /day for trade effluent emissions to water. The current licence authorises a discharge of 168 m 3 /day. In addition, the licensee has requested increased concentration limits for total dissolved solids (2,000 mg/l compared to 1,300mg/l) and ammonia (5mg/l compared to 0.5mg/l). The licensee has assessed the assimilative capacity of the receiving water to accept the cumulative discharge from the Phase I and II power plants. There is sufficient assimilative capacity in the Ward River for the requested emissions. The RD maintains the same monitoring requirements for emissions to water as the current licence. Due to the sensitivity of the Ward River the following conditions are also included in the RD: the licensee shall assess methods to minimise emissions to water and maximise recycling and recovery as part of the Environmental Management System; and the licensee shall assess the feasibility of connection to the Local Authority drainage system for discharge of trade effluents. Page 5 of 8

6 SURFACE WATER: Surface water run-off from the installation drains via oil interceptors to a surface water inspection holding pond, prior to discharge at emission point D1 into the adjacent quarry drainage network. The surface water drainage systems for Phase I and Phase II are not entirely separate, therefore the monitoring point for surface water is shared and is identified as I-SW. The RD maintains the requirement on the licensee to carry out composite sampling of the surface water discharge, with quarterly monitoring of a range of specified parameters. Firewater Retention The current licence (Reg. No. P ) does not specify requirements in relation to firewater retention at the installation. Condition 3 of the RD requires the licensee to carry out a risk assessment to determine if the activity should have a firewater retention facility and to implement a suitable risk management programme in the event that a significant risk exists for the release of contaminated firewater. EMISSIONS TO GROUND There were no proposed discharges to ground at the time of the original licence application in Sanitary effluent from the administration and workshop buildings was to be treated on site to standards of 20 mg/l BOD 5 and 30 mg/l suspended solids using a proprietary bioaerator prior to discharge to the quarry drainage system. However, the installed biodisc treatment unit experienced difficulties in achieving the effluent licence limits, resulting in effluent being tankered off-site for disposal. On 12/07/05 the Agency approved the licensee s proposal to install a raised percolation bed to provide tertiary treatment of the sewage effluent from the biodisc unit (Ref. M483/C12MG01). The percolation bed came into operation in October In the review application, the licensee has carried out an assessment of the sanitary effluent treatment system capacity. The percolation bed is based on a load of 900 litres per day (30 30 litres/person/day) and 600 grams BOD/day (20 grams BOD/person/day). Based on predicted flow, there is sufficient capacity to treat the sanitary effluent associated with both Phase I and Phase II developments. Nonetheless, Condition 6 of the RD requires the licensee to reassess the treatment system capacity when the Phase II power plant becomes operational, and to undertake upgrading works as necessary in accordance with the Agency s Wastewater Treatment Manuals. The RD requires that the sanitary effluent treatment system be included in the site s maintenance programme, as required under Condition There are three wells on the Phase I site, one is an operational supply well, a second is a backup well and the third has been decommissioned. Schedule C requires the licensee to monitor the ph and conductivity of the raw water supply to the installation on a monthly basis, and to monitor total ammonia and total and faecal coliforms on a biannual basis. WASTE No new wastes will be generated as a result of the licence review. HCl contaminated water associated with the storage tank scrubber is removed for disposal off-site by a licensed waste disposal company. Waste recovery/disposal is controlled by licence conditions, which require the waste to be transferred to authorised waste recovery/disposal facilities. NOISE Results of the 2005 noise survey show that emissions from the power station are similar by day and night and are within the 55/45 db(a) limits specified in the current licence at noise sensitive locations. The company have received occasional noise complaints from neighbouring residents and have identified the noise source as ground-working associated with the construction of the Phase II development. The RD maintains the requirement for an annual noise survey, to be carried out in accordance with the Agency s guidance note. Page 6 of 8

7 HABITATS The installation is an existing site located on former agricultural land with no designated ecological status. There will be no impact on any designated sites as a result of the licence review. DECOMMISSIONING AND ENVIRONMENTAL LIABILITIES The current licence and amendment dated 02/09/05 do not require the licensee to prepare a Residuals Management Plan (RMP) for the decommissioning or closure of the site or part thereof, or to carry out an Environmental Liabilities Risk Assessment (ELRA) to address any liabilities from past or present activities. The RD includes standard conditions which require the licensee to prepare an RMP which shall be reviewed annually (Condition 10), and to carry out an ELRA which shall be reviewed as necessary to reflect any significant changes on site and in any case, every three years (Condition 12). FIT & PROPER PERSON ASSESSMENT The licensee s experience, technical abilities, financial and legal standing would qualify them as Fit & Proper Persons. COMPLIANCE RECORD: Five site inspections and one audit of this facility have been carried out since the licence was issued in Three notifications of non-compliance have been issued to the licensee in that time, relating to the use of un-approved waste contractors, inadequate bunding, and nonnotification of a new emission point associated with the HCl tank scrubber. Overall the site maintains a good level of compliance with the current licence Reg. No. P SUBMISSIONS / COMPLAINTS: No submissions were received in relation to this review application. Since issue of licence Reg. No. P , there have been a number of noise complaints received by the company, most recently in relation to construction of the Phase II power plant. CHARGES: The financial charges invoiced for 2005 and 2006 were 7,729 and 8,888 respectively. The annual charge proposed in the RD is 10,129. This reflects the predicted enforcement effort required for the installation and is in line with the charges proposed by the Office of Environmental Enforcement for RECOMMENDATION: I recommend that the Recommended Determination be issued subject to the conditions and for the reasons as drafted. Signed Aoife Loughnane Inspector, Office of Licensing & Guidance Procedural Note In the event that no objections are received to the Proposed Determination of the application, a licence will be granted in accordance with Section 87(4) of the Environmental Protection Agency Acts 1992 and 2003 as soon as may be after the expiration of the appropriate period. Page 7 of 8

8 Appendix A Revised site boundary: The outer perimeter of the entire site is marked in red and represents the Phase I boundary, with the exclusion of areas designated as Phase II which are marked in green e.g., new turbine building, new distillate oil storage tank & associated bund, new Phase II process effluent tank, new Phase II firewater tank and new workshop & storage area. Page 8 of 8