37 Town Range Gibraltar Tel: (350) 20070620 Fax: (350) 20074119
Determination of an Application for a PPC Permit under the
Pollution Prevention and Control Act 2001
Decision document recording the decision-making process
Note: all references to the “PPC Regulations” are to the Pollution Prevention and Control Act 2001.Administrative details
Duly made application date 20 April 2009 Permit number (the “Permit”) PPC003
Applicant (the “Applicant”) Gibraltar Electricity Authority Address/location of installation Lathbury Barracks power station (the “Installation”) Lathbury Barracks
Gibraltar.
Name of Permitting Officer Louis Poggio Name of Authorising Officer Francis Martin
Contents
Introduction and summary of decision
Part A General Issues
Part B The installation and its management
Part C Operations and releases
Part D Other legal considerations
Annex 1 Consultee and public responses
Annex 2 Improvement Conditions
Annex 3 Pre-operational Conditions
INTRODUCTION
Purpose of this document
The Environmental Agency has decided to issue the Permit having regard to the information received from the Applicant, responses to the public consultation on the application, and the Agency’s assessment of all this material, as explained in this document.
The decision document explains how the Applicant’s application has been determined and why the specific conditions in the Permit has been included. It is a record of the decision-making process to show how all relevant factors have been taken into account in reaching our final position.
The Permit contains many conditions taken from the standard non-landfill PPC Permit template (version 3) of the Environment Agency (England and Wales). The conditions were developed in consultation with industry having regard to the legal requirements of the PPC regulations and other relevant legislation. This decision document does not include an explanation for these standard conditions. Where they are imposed we have considered the application and accepted the details are sufficient and satisfactory to control that aspect of the operation. This decision document does, however provide an explanation for the use of alternate conditions where our Permit template allows for two or more options. Emission and monitoring compliance levels and any additional conditions that have been imposed in order to take installation-specific factors into account are explained.
In this document the terms Applicant and Operator are interchangeable. This is because the draft conditions of the Permit refer to the Operator and this is what the Applicant will become if the Permit is granted.
Summary of the decision
We are issuing a PPC permit to Gibraltar Electricity Authority to operate a power station at Lathbury Barracks, Gibraltar. Where the permit includes standard conditions, these have been considered to be appropriate for the Installation, in particular in ensuring that all appropriate measures will be taken against pollution and that no significant pollution will be caused. We consider in reaching that decision we have taken into account all relevant considerations and legal requirements and that the Permit will ensure that all appropriate measures will be taken against pollution and that no significant pollution will be caused as a result of the operation of the site.
Part A – General Issues
A1 Administration
This section includes administrative information relating to the Application and information about the Applicant and the Installation.
The Application was duly made on 20 April 2009.
The Operator has not made a claim for commercial confidentiality. We have not received any information in relation to this application that appears to be confidential in relation to any party.
The Application was advertised and consulted in accordance with the PPC Regulations. The Application was advertised in the Gibraltar Chronicle and the Gibraltar Gazette on 30th April 2009. Any responses received are summarised in Annex 1. We have taken these into consideration as described in Annex 1 when determining the Application.
A request for further information was sent to the Applicant on 25 June 2009 to obtain additional information in regards to the Application. This was responded to by the Applicant on 26 August 2009 with an updated response sent on 28 September 2009.
A2 Description of the installation
The power station will be constructed in several phases. The first stage of the plant will begin operation in 2011 and initially the plant will be capable of generating some 64 MW of electrical power. The plant will then be extended over the course of the next 25 years to reach an eventual installed capacity of about 88 MW electrical output by 2032.
The plant will be fired on distillate fuel oil (DFO).and will initially comprise nine x 6.5 to 8 MWe medium speed generating units rising to up to twelve x 6.5 to 8 MWe units by 2032. Each unit will consist of a diesel engine, electricity generator, and flue gas discharge facilities. There will initially be three chimneys each chimney having three flues, such that each diesel engine discharges from its own flue. A fourth chimney will be added for the further 3 units at a later date.
The flue gases will pass through a selective catalytic reduction (SCR) plant where the oxides of nitrogen formed in the combustion process in the diesel engines will be converted to nitrogen and water vapour by reaction with ammonia over a catalyst bed prior to discharge through dedicated flues.
Surface water from the site will be discharged to sea via a cliff outfall, all surface water from process areas of site will be discharged via an oil interceptor.
The power station will use a closed circuit cooling system with an associated water treatment plant.
The fuel supply system will consist of a new unloading line from the harbour on the boundary of HM Naval Base and Cammell Laird Yard to allow discharge of diesel oil from coastal barges moored alongside the wharf.
The pipeline will be routed to the east side of Gibraltar within a dedicated pipeline through exisiting tunnels. The pipeline will then connect to new oil storage tanks situated within the existing Admiralty Oil Reservoir No 4 located within the Rock. Also located within the Admiralty Oil Reservoir No. 4 will be fuel transfer pumps to transfer diesel oil to service tank(s) located at the power station. The fuel transfer lines will be routed from the storage tanks to the power station site service tanks via a pipeline which will run through a second tunnel and then alongside the Hole in the Wall Road.
Two service tanks will be located at the power station site, each sized to allow for 12 hours operation at peak load.
The only discharges to the environment from the process are combustion exhaust gases from the 12 flues (4 stacks).
The small amounts of aqueous effluent generated will be stored in a tank on site and then sent for disposal in a suitable waste treatment facility.
Waste water is discharged via a treatment sump to sewer.
The plant will be equipped with a black start unit that will comprise of a diesel plant of approximately 250kW. The purpose of this unit will be to provide power to (re)start the main diesel engines when necessary.
A3 Operator competence
We are satisfied that the Applicant (now the Operator) is the person who will have control over the operation of the installation after the grant of the Permit. We are satisfied that they will be able to operate the Installation so as to comply with the conditions we have included in the Permit.
The applicant has indicated within their application that an Environment Management System (EMS) will be developed for the site.
A4 Requirements for Specified Waste Management Activities (SWMAs) The Applicant has replied to application question B7.1 stating that the installation does not contain a SWMA and we agree with this assessment. As no Specified Waste Management Activity is to occur on site, there is no requirement for an individual on site to obtain a Certificate of Technical Competence (COTC) in this respect.
Part B : THE INSTALLATION AND ITS MANAGEMENT
B1 General Management Permit condition 1.1
Based upon the information submitted in the Application, we are satisfied that sufficient financial, technical and manpower resources are available to the Operator to ensure compliance with all the Permit conditions.
However, the Operator does not yet have a management system in place as the site has not been constructed at the time of Permit issue. Therefore, Pre-operational condition POC4 in Table S1.3 of the Permit requires the Operator to send a copy of their Environment Management System (EMS) to the Environmental Agency for review at least 1 month prior to starting operations at the site. The Operator is also required to indicate any plan they may have to obtain external accreditation such as ISO 14001 approval for their EMS.
B2 Accident management plan Permit Condition 1.2
We are satisfied that appropriate measures will be in place to ensure that accidents that may cause pollution are minimised. As the site has not been constructed at the time of Permit issue, no accident management plan has been developed. There is, however, a commitment within the Application to develop an Accident Management Plan during the detailed design phase of the site development.
We have included pre-operational condition POC5 to require the Operator to submit an Accident Management Plan in line with Section 2.8 of the IPPC Technical
Guidance Note Combustion Activities, v3.02, dated 27 July 2005, for approval at least 1 month prior to commencement of operations at the site. Operations can not commence unless the plan has been approved.
The existence of an Accident Management Plan is a requirement of the PPC Permit, and we are satisfied that by requiring this to be produced as a pre-operational condition that this does not prejudice the wider determination of the Permit. The capacity of the DFO storage tanks to be located within the Admiralty Oil
Reservoir No 4 on the East side is at present unknown and it is therefore not known whether the site will be subject to regulation under Part IIA of the Public Health Act (Control of major accident hazards involving dangerous substances)
B3 Energy efficiency Permit condition 1.3
We are satisfied that appropriate measures will be in place to ensure that energy is used and generated efficiently. The conversion efficiency of the diesel engines to be used is predicted as being 47% within the Application. This level of conversion efficiency is high in respect of liquid fuels and can be regarded as BAT as the option of using natural gas (which can achieve greater conversion efficiency) is not available to the Operator as there are no natural gas supplies in Gibraltar. Use of diesel
Gibraltar. The Operator has also indicated within the Application that the diesel engines will be constructed in such a way as to be able to be coupled with a steam generating system if the demand for steam should arise in the vicinity. This would further increase the conversion efficiency of the diesel engines if steam users should come available.
The Operator is required to report with respect to energy generation and usage under condition 4.2.1/2 and Schedule 5. These parts of the Permit require the Operator to submit information to the Environmental Agency on an annual basis to detail the amount of distillate fuel oil used on the site during the previous calendar year and the amounts of electrical energy produced, consumed at the site and exported from the site. This data will enable the Environmental Agency to ensure that the predicted 47% conversion efficiency of the power generating process is realised.
Condition 1.3 of the Permit requires that there are regular on-going reviews of energy efficiency at the site and that where improvements are identified that they are
implemented.
B4 Efficient use of raw materials
Permit condition 1.4 Based upon the information submitted in the Application we are satisfied that the appropriate measures are in place to ensure the efficient use of raw materials and water. There is evidence within the application to indicate that the use of water on the site will be optimised. Example being the use of closed circuit cooling systems with water treatment plant which minimises the amount of ‘fresh’ water required. In order to ensure that raw materials continue to be used as efficiently as possible on site Condition 1.4.1. of the Permit requires an audit to ensure the efficient use of raw materials (including water) at least once every 4 years.
.
B5 Avoidance, recovery and disposal of wastes produced by the activities Permit condition 1.5 Based on the information submitted in the application we are satisfied that the
appropriate measures are in place such that waste production will be avoided as far as possible, and where waste is produced it will be recovered unless technically and economically unfeasible. We are satisfied that the Operator’s justification for their proposed waste disposal option shows that such waste that does arise from the Installation that can not be recovered will be disposed of using a disposal method that avoids or reduces any impact on the environment. The Application indicates that waste streams from the process will be low volume and that any waste produced will be disposed of through a suitable licenced waste facility.
As part of their response to pre-operational condition POC3 of Table S1.3 of the Permit, the Operator is required to send a detailed report of the location and the associated infrastructure for each of the waste storage areas on site. This will enable the Environmental Agency to assess whether adequate infrastructure is in place to
contain any accidental spillage of waste that may occur at the site, therefore protecting the surrounding environment.
B6 Site Security
Permit condition 1.6 Based upon the information submitted in the Application, we are satisfied that
appropriate infrastructure and procedures will be in place prior to start up of operations at the site to ensure that the site remains secure.
B7 Multiple operator installations
This is not a multi-operator installation. Therefore the standard condition relating to multi-operator installations has not been included within the permit.
B8 The permitted activities
Permit condition 2.1 We have determined that the Installation comprises the following activities listed in Part 1 of Schedule 1 to the PPC Regulations and the following directly associated activities.
Listed activities.
Schedule 1, Section 1.1) – combustion installations with a rated thermal input
exceeding 50 megawatts
The combustion units on site included within this listed activity are:
(i) twelve compression ignition engines of a nominal thermal input of 17MW each. (ii) one auxiliary diesel engine of a nominal thermal input of approximately 625kW. Directly associated activities.
Distillate fuel oil receipt, transfer and storage – Transfer of distillate fuel oil from
coastal barges to pipeline and onwards to storage in the new oil storage tanks situated within the existing Admiralty Oil Reservoir No4. Transfer of distillate fuel oil from these tanks to Lathbury Barracks site storage tanks and from there to diesel engines.
Ammonia solution (Adblue) receipt, transfer and storage – receipt of ammonia solution by road tanker at side, transfer to on-site bulk storage tank, dilution and transfer to SCR plant.
Water treatment (‘softening’) plant - From initial receipt of water from mains supply
and after that from closed cooling system through treatment and return to ‘softened’ water tank and from there to closed cooling system.
Electricity generators(gas turbines) - Conversion of hot flue gases from
compression ignition engines to mechanical and through to electrical energy with export of electrical energy to the Gibraltarian electricity supply system.
The activities comprise a single installation because
(i) they are successive steps in one integrated industrial activity. (fuel supply, fuel storage and movement, diesel engines, gas turbines).
(ii) Directly associated activities (Distillate fuel oil storage and handling, water treatment plant, gas engines), as these activities serve the listed activity, are technically connected and can impact the overall emissions from the site.
B9 The site
Permit condition 2.2 The Operator has provided a plan which we consider is satisfactory, showing the site of the Installation and its extent. A plan is included in the permit at Schedule 2, and the Operator is required to carry on the permitted activities within the site boundary. The storage of distillate fuel oil within the new oil storage tanks situated in the existing Admiralty Oil Reservoir No4 on theEast side is considered to be part of the installation although geographically removed from the main site. This is as the tanks are technically linked to the power station site by means of pipelines and the power station could not operate efficiencly without the additional oil storage that these tanks afford the installation. All pipelines between the new oil storage tanks situated within the existing Admiralty Oil Reservoir No4 and the docks and all pipelines between thenew oil storage tanks situated within the existing the Admiralty Oil Reservoir No4 and Lathbury Barracks are also considered as part of the installation.
As yet no plan of the site sewer and drainage system has been received from the Operator because the site is in the early stages of development. The Operator is required to submit a plan of the sewer and site drainage systems to the
Environmental Agency for approval at least 3 months prior to operations commencing at the site as part of their response to pre-operational condition POC3 of Table S1.3 of the Permit.
Part C : Operations and releases C1 Operating techniques
Permit condition 2.3/table S1.2 We have specified that the Applicant must operate his Installation in accordance with the following descriptions in their Application
Description Parts Omitted Justification
The response to section B2.1, and B2.2 in the Application.
None N/A
Response to pre-operational condition POC1, POC2, POC3, POC4, POC5, POC6 and POC7 as approved in writing by the Environmental Agency.
As stated in written final approval to the response to POC1, POC2, POC3, POC4, POC5, POC6 and POC7
This ensures that the layout of the site, associated drainage and pipework, environmental management system, commissioning monitoring and reporting, noise, accident management and site
closure/decommissioning plans are in line with that approved by the Environmental Agency. BAT Assessment of proposed operating techniques.
1. Combustion unit and consideration of Combined Heat and Power generation. In order to comply with the EU Air Quality Directive, the three existing power stations at Waterport, OESCO and ISGS (providing a total generation capacity of
approximately 60MW) will need to be decommissioned by the end of 2010, due to exceedances of the objectives for nitrogen dioxide and particulate matter. We agree with the Applicant that the main technology candidates for this level of generation are:
• Diesel CI Engines
• Gas Turbines, operating in simple cycle (SCGT) • Gas Turbines, operating in combined cycle (CCGT) • Steam Turbines, with fired boiler
The Applicant states that CCGT power stations are more efficient than SCGT plants however they are not suited to systems with a varying demand profile, being more appropriate for constant, base load operation. In addition, the capital costs are prohibitively high for CCGT plants of less than 100 MW, and thus would render the project unfeasible.
Steam turbines, with boilers using oil or coal as fuel would also have a prohibitive capital cost, at the size required, and are significantly less efficient than gas turbines and diesel engines, at small unit sizes. With capital and operating costs significantly higher than the other options, this type of plant is not considered appropriate for Gibraltar.
Diesel engines and gas turbines operating in simple cycle are considered to be the most appropriate conventional type of generation for Gibraltar. Both types can
generally be specified to run on either light fuel oil (i.e. marine diesel or gas-oil) or gas, or can be converted at a later stage should gas become available. However, simple cycle gas turbines in the size range required are much less efficient than diesel engines and would consume significantly more fuel, especially under part load conditions. The forecast power demand in Gibraltar is too small for combined cycle or steam plant to be economic due to the high capital costs for small capacity plants. Diesel units of nominal capacity 6.5 to 8 MW have been selected based on a number of factors. Low sulphur diesel oil is currently the only fuel used for power generation in Gibraltar and is likely to be the only available fuel in 2010, by which time any replacement plant would need to be commissioned. There is the potential to take a gas supply from the Spanish network for power generation in Gibraltar, however it would take several years to conclude the necessary investigations and agreements and construct a pipeline connection, so although the supply of gas via pipeline may be considered in the long term, it could not be expected to be available in time for start-up of the new power station in 2010. In addition, the security of supply would suffer as Gibraltar would be dependant on a single source of gas. The size of units (rated output) and number to be installed has been chosen to suit the varying
demand profile, to provide for a reliable power system whilst operating the engines as close as possible to their maximum efficiency.
We agree with the Applicants reasoning and that a series of small diesel
compression ignition (CI) engines are BAT for the Lathbury Barracks power station development.
The power station also proposes air blast radiator cooling. We agree that air cooling can be considered BAT as:
a) the size of the power station is such to make air cooling feasible without the need for large electrical and land usage.
b) Fresh water is limited in Gibraltar and saline water would need a large amount of energy to pump it to the Lathbury Barracks site. Therefore the use of a closed circuit cooling system minimises the amount of fresh water required.
The air blast radiator cooling system proposed for Lathbury Barracks is the most common technology choice for diesel engine-based power stations and is well proven in operation. The diesel engines are cooled by the recirculation of water through the cylinder blocks. The water leaving the engines will be at elevated temperature and will pass through the air blast radiator, to reject the excess heat to atmosphere, and returned to the engines. The water will pass through finned tubes and sufficient air will be blown across the tubes to achieve the required cooling duty.
The cooling system will be designed to readily achieve the maximum required cooling duty to suit the ambient conditions of the site. Suitably generous margins will be incorporated into the design to provide an appropriate factor of safety.
The Operator is required by pre-operational condition POC2 to submit a report to the Environmental Agency detaling the final constructed design of the power station. Pre-operational condition POC5 also requires the Operator to submit a commissioning plan for approval.
2. Distillate fuel oil receipt, storage and on-site transfer.
New oil storage tanks will be installed within the existing Admiralty Oil Reservoir No4 within the Rock. There will be an enclosed system of pipelines with
appropriate containment and preventative maintenance regime to transport the distillate fuel oil from the dock side to the tanks within the Admiralty Oil Reservoir No4 and then onwards to the Lathbury Barracks site.
3. Stack height and design.
Figure 1 below submitted by the Applicant as part of their response to the request for additional information shows the predicted ground level concentrations (GLC) resulting from full load operation of the proposed plant, for a range of stack heights. The secondary axis shows the “cost per µg/m3 reduction” of increasing the stack height by 1m. The cost of one stack has been assumed to be 10,000 GIP per metre.
Figure 1 – Cost-Benefit of Stack Height Increases
As shown in Figure 1, the process contribution to the maximum GLC reduces as the stack height increases.
The Applicant argues that beyond a 40m stack height, the Cost:Benefit ratio increases rapidly as the incremental environmental benefit reduces. It is therefore considered that a stack height of 40m is appropriate for the proposed plant.
We agree that a stack height of 40 metres is appropriate for the intial stages where actual process contribution will be lower than that indicated by the above graph, as above 40 metres there is the cost of abatement starts increasing more rapidly per unit of reduction in maxima ground level concentrations. However, based on current prediction of increasing power demand in Gibraltar we are concerned that a 40 metre stack will be insufficient to ensure minimal impact on the environment over the lifetime of the power station.
Therefore as the power output of the power station slowly increases over its lifetime there may be a point in a few years time at which the greater cost per unit
reduction in ground level concentrations can be justified as BAT due to increasing ambient concentrations.
Table : Comparison of maximum process contribution (PC) from Lathbury Barracks to NO2 annual mean and short term with Predicted Environmental
Concentration (pec) at identified receptors vs Air Quality Standard.
Output 9 engines 12 engines
% AQS %AQS
pc
Long term Short term
pc
Long-term Short-term
Initial average 1.22 3.1 0.61 4.38 10.9 2.19
Initial peak 2.78 7.0 1.39 10.49 26.2 5.25
max capacity 4.27 10.7 2.13 13.16 32.9 6.58
pec %AQS pec % AQS
Long-term Short-term Long-term Short-term Long-term Short-term Long-term Short-term
Initial average 27.22 53.22 68.1 26.6 30.38 56.38 75.6 28.2 Initial peak 28.78 54.78 72.0 27.4 36.49 62.49 91.3 31.2 Max capacity 30.27 56.27 75.6 28.1 39.16 65.16 98.0 32.6
Max capacity based on an output of 7MW per engine.
All process contribution data is based on 40 metre stack and 80% NOx reduction. Short-term background has been assumed to be 2 x long-term background in line with H1 methodology.
The current background ambient level of NO2 as an annual average in the
location of Lathbury Barracks has been measured at 26µg/m3, as compared to an Air Quality Standard of 40µg/m3. Therefore, as the power station output
increases the annual average (long-term pec) becomes very close to the AQS based on current background levels. The background levels will likely change with time and at this stage it is not possible to predict how the background levels (other than those of the Lathbury Barracks power station) will change over the period.
Therefore we have added improvement condition IP1 to the permit in order to require the Applicant to assess when the environmental impact of NOx emissions from the site will need to be reduced further and whether (if required) this can be achieved by increased SCR dosing and/or increasing the stack heights.
The modelling presented as part of the site’s Environmental Statement indicates that some areas of Gibraltar (e.g. Rosia Road) are already exceeding the NO2 annual average Air Quality Standard (AQS) and therefore, we would need to ensure that the impact of the new power station on this area is negligible.
However, as the current power stations in Gibraltar will be closed and replaced by the Lathbury Barracks power station then we also need to consider the reduction in NO2 levels in this area as a result of the closure of the three existing power
stations.
The process contribution from the existing power stations based on air dispersion modelling is 21.9µg/m3 whereas the additional process contribution from the Lathbury Barracks power station at Rosia Road will be up to 3µg/m3. Therefore, the replacement of the existing power stations by the Lathbury Barracks power station will result in a significant reduction in the annual average NO2 ambient
As the number of diesel engines operating at any one point in time will be very variable owing to the variability of electrical demand in Gibraltar, in order to ensure that the air emissions are optimally dispersed the 3 flues within each of the stacks which are connected to individual engines should extend to the top of the 40 metre stacks and discharge independently of each other at the top of the stack. The monitoring and testing requirements as set out in Table S4.1 of the Permit are based on this configuration of flues within the stacks at the site.
Permit condition 2.3/Table S3.1 We have specified the following limits and controls on the use of raw materials and fuels
Raw Material or fuel Specifications Justification
Distillate fuel oil <0.1% w/w sulphur In line with sulphur in fuel
directive.
The Permit does not authorise the acceptance of fuels, other than those specified in the above table, or materials classified as wastes at the installation.
The Application gives details of the proposed route of the fuel lines that will transport distillate fuel oil from the dockside to new oil storage tanks situated within the existing the Admiralty Oil Reservoir No4 and onwards to the storage tanks on the Lathbury Barracks site. Pre-operational condition POC3 requires the Operator to inform the Environmental Agency of the actual route of the proposed pipelines, containment for these pipelines and preventative maintenance regime for the pipeline at least 2 months prior to start of operations at the site. This pre-operational condition is set in order that the Environmental Agency are aware of the final route of this pipeline and are satisfied that the containment afforded to the pipeline and the preventative maintenance regime are sufficient to ensure that a risk of an accident causing damage to the environment is minimised as far as possible.
C2 Off-site conditions
Permit condition 2.4 No off-site conditions stated within the Permit.
C3 Improvement Conditions
Permit condition 2.5 Based on the information in the Application, we have decided to impose one
improvement condition. This is listed in Annex 2 - justification for this is provided at the relevant section of the decision document referred to within the relevant table in Annex 2.
C4 Pre-operation conditions
Permit condition 2.6 Based on the information in the Application, we decided to impose pre-operational conditions. These are listed in Annex 3 - justifications for these is provided at the
relevant section of the decision document and these sections are referred to within the relevant table in Annex 3. We are using these conditions to require the Operator to confirm that the details and measures proposed in the application have been adopted or implemented prior to the operation of the facility. At the point of Permit issue it is not possible to obtain such detailed information as the site is yet to be constructed.
C5 Closure and decommissioning
Permit condition 2.7 Based upon the information submitted in the application we are not fully satisfied that the appropriate measures are in place for the closure and decommissioning of the installation at this stage. This is due to the site being in early stages of development. We have set a pre-operational condition POC8 in Table S1.3 of the Permit to require the site to develop a closure and decommissioning plan based on the final
construction of the site. The permit requires that they submit such a plan for approval at least 1 month before operations start.
C6 Site protection and monitoring programme
Permit condition 2.8 The applicant has provided a site report the main elements of which are:
Site location.
The entire Lathbury Barracks power station development encompasses three main sites: The site of the main power station development covers about 1.9ha and is situated on land adjacent to the Ministry of Defence Lathbury Barracks Base in the southeast of Gibraltar. Associated fuel storage will also be developed alongside the power station. Land in the immediate vicinity of the power station site boundary is characterised by scrubland with small shrubs, grass and hardstanding Storage tanks will be located within the east side of the rock of Gibraltar (Admiralty Oil Reservoir No4). There will also be a fuel supply system linking the tanks with the new power station, which will consist of a new unloading line from the harbour on the boundary of the HM naval base and Cammell Laird Yard to allow discharge of diesel oil from coastal barges moored alongside the wharf.
The pipeline will then cross Dockyard Road in a culvert and from there will likely be routed to the east side of Gibraltar to the entrance of the Admiralty
East-West(Comcen) tunnel. The pipeline will then connect to the existing Admiralty Oil Reservoir No 4 located within the Rock on the east side . New tanks will be constructed within the Admiralty Oil Reservoir No4 for fuel storage.
A plan of the site and the storage tanks is shown in Schedule 2 of the Permit. Beyond the developed area to the north of the site the land rises sharply to a high point of over 400 m. This area is naturally vegetated and forms part of the Upper Rock Nature Reserve and The Rock designated site of Community interest (SCI) for wildlife.
Site history.
The site of the proposed power station has been used as a training ground, parade ground and barracks since the 1930’s, before which, it remained undeveloped. There is no evidence that previous site uses have impacted on the ground conditions of the proposed site at any point in the past.
There is evidence that the groundwater and bedrock underlying the East Side Tanks has become contaminated with petroleum hydrocarbons at some point in the past. A full survey of the tanks will be undertaken prior to development. The intention is that the existing Admiralty Oil Reservoir No4 will act as secondary containment for the new fuel oil tanks in the area. Where necessary an additional layer of containment may be placed within the existing Admiralty Oil Reservoir No4.
Proposed pollution prevention measures.
All areas of the proposed plant will be on hardstanding. All storage tanks will be contained within a bund sized to hold 110 per cent of the volume of the largest tank or 25 per cent of the volume of all tanks, whichever is greatest. Bunding and
hardstanding will provide an impermeable barrier to percolation of any substance used and stored on site.
An oily waste water drainage system will drain all areas where oil spillages could occur. The design will incorporate oil interceptors and sediment traps.
Once the plant has been commissioned, the monitoring of hardstanding areas and bunds will be undertaken as part of the Site Protection and Monitoring Plan (SPMP) and Environmental Management System (EMS).
Additionally, the SPMP will monitor the integrity of the pollution prevention infrastructure, thus minimizing the likelihood of pollution.
In addition, DFO will be stored in a controlled environment within large storage tanks in the Admiralty Oil Reservoir No4 and will be transferred to the plant as necessary. Therefore, no excess DFO will be stored on site at any time.
Source and pathway of potential pollution
The main areas of potential pollution are from the storage and use of distillate fuel oil and effluent from water treatment plant chemicals.
The installation will be constructed with appropriate environmental pollution
prevention measures including appropriate bunding, impermeable hardstanding on site, sewage discharged to a sewage treatment plant, water treatment plant effluent treated in effluent treatment plant and oil interceptors and foul drainage on site. Once the plant becomes operational, an EMS will be implemented to identify potential pollution risks from the operational plant and control procedures documented. There are no surface water features on the proposed site of the Lathbury Barracks Power Station or in the immediate vicinity of the east side storage tanks. The
Southern Waters is an area of the Mediterranean sea approximately 20m west of the development. The area has been designated an SCI due to the importance of several species including Bottlenose Dolphins, loggerhead Turtles, and also the presence of submerged sea caves. However, no site drainage (of effluent or surface water) during operation will discharge into the sea. Therefore, the proposed development is not expected to be any detrimental effect on marine ecology.
Conceptual site model
The findings of the desk study and a visit to the site were used by the Applicant to develop the conceptual site model (CSM) for the site.
1. Geology
The geology of the site comprises of (from ground level downwards): • Made Ground (Concrete, asphalt and topsoil)
• Drift deposits (sands, gravels and clays) • Solid geology of limestone
The Site investigation comprised the excavation of 11 boreholes to depths ranging from 4.60 – 13.40 metres below ground level (m bgl) and eight trial pits ranging from 0.8-2.70 m deep across the entire site.
A relatively thin capping of made ground (thickness of strata ranged from 0.60 – 5.50m) was recorded in all trial pits and in boreholes 1, 3, 4, 5, 6, and 7. But not in borehole 2 in the southeast of the site and Borehole 8 in the centre of the site. The site investigation characterised the made ground as “Made Ground and topsoil of a varying fill material. Very heterogeneous, comprising sands, clays, gravels of various lithology and man made inclusions such as ceramics”. Underlying the made
ground, drift deposits of sands, gravels and clays were recorded. This layer was described as “Clayey sand and sandy gravelly clay with inclusions of limestone cobbles.” Drift deposits were recorded in boreholes 1 (far east of the site), 3 (east of the site), 4 (northeast of the site), 6 (centre of the site) and 7 (centre of the site). Drift deposits were recorded at thicknesses between 0.79 – 7.90m. deposits
were recorded in six boreholes at depths between 5.45-12.2 m bgl.
Underlying drift deposits, limestone bedrock was found in all boreholes, apart from borehole 1 (in the northeast of the site).
The site underlying the Lathbury Barracks is situated on Limestone Breccia, which is characterised by Solid limestone bedrock. Depth to base rock was not proven in any boreholes, suggesting that limestone underlies the site at significant depth.
Although no detailed intrusive site investigations have been undertaken for the east side oil storage tanks, previous desk studies and geological reports have suggested that the East Side Tank Caverns are within the Gibraltar Limestone Formation, which forms the bulk of the main ridge of the Rock of Gibraltar. This area is classified as a relatively homogenous, fine grained, jointed limestone which is partially dolomotised in places.
There is no evidence of mining activity on the site of the proposed power station development.
Previous studies Lathbury barracks Environmental Statement, GIBB Environmental, 2008) indicates that the site of the proposed power station and surrounding area is situated above a major aquifer (relating to the limestone bedrock).
Due to the height and location of the proposed power station development site (approximately 120m above sea level), it is unlikely that the site is at risk from flooding. In addition, there are no surface water features present in the immediate vicinity of the site.
2. Soil contamination.
To assess the level of contamination across the site, 6 soil samples were taken from representative substrata from trial pits and submitted to a UKAS accredited
laboratory for the analysis of a range of determinands.
All determinands were measured against relevant screening criteria (adjusted Dutch Intervention values). Exceedance of several contaminants was noted from laboratory analysis:
• Three of the six samples analysed contained elevated concentrations of arsenic. Samples were from soil horizons within the top 1m of trial pits 1, 2 and 3 (in the northeast of the site).
• One of the samples analysed contained elevated concentrations of Napthalene. The sample was taken from Trial Pit 5 in the south of the site.
• Two samples contained elevated concentrations of Benzo(a)pyrene. Samples were from trial pits 5 (south of the site) and 8 (southwest of the site).
Although small amounts of contaminants were found on site which exceeded laboratory detection limits, no significant risk is posed to future site users, as the power station development will be constructed entirely on hardstanding, which will break the pollutant linkage between source and receptor.
No groundwater was encountered during the ground investigation and hence, no samples of groundwater were analysed for contaminants.
Previous reports have suggested that groundwater underlying the East Side Storage Tanks is contaminated with petroleum hydrocarbons. A full assessment of the
condition of the storage tanks will take place prior to construction. To ensure there are no leaks and where necessary additional construction will occur to ensure that the pollutant linkage between source and receptor is broken.
3. Other Receptors/ Species of note
The site of the proposed power station development lies between two areas of the Rock of Gibraltar SCI. The southern Waters SCI is also located in close proximity to the southern edge of the site. Although there is the potential of impacting on these significant ecological receptors, care will be taken during construction
and operation to limit any adverse effects by the implementation of an appropriate EMP and SPMP. Modelling indicates that the amount of nitrogen deposition on most areas of the SCI due to emissions of NOx from power generation in Gibraltar will be reduced by the development of the Lathbury Barracks power station and
decommissioning of the three current power stations. 4. Land Pollution History
The site of the proposed power station has been used as a training ground, parade ground and barracks since the 1930’s, before which, it remained undeveloped. There is no evidence that previous site uses have impacted on the ground conditions of the proposed site at any point in the past.
There is evidence that the groundwater and bedrock underlying the Admiralty Oil Reservoir No4 has become contaminated with petroleum hydrocarbons at some point in the past. A full survey of the Admiralty Oil Reservoir No4 will be undertaken prior to development.
5. Uncertainties in the CSM
In developing the conceptual model for the site the following assumptions have been made:
• Site investigations have only been conducted to a maximum depth of 13.4 m bgl. Consequently, the extent and nature of permanent geology has also been
inferred from other sources (e.g. geological maps). • The geological strata are uniform across the site.
• The groundwater is at a significant depth below the site. Conclusion
The Application Site Report was prepared in accordance with the PPC Regulations and the relevant UK Environment Agency guidelines. Information collected by the Applicant during this process has not revealed any environmental incident or incidents associated with the previous use of the site, therefore, the Environmental Agency agrees that it is unlikely that any gross contamination of the site has occurred.
However, as some hydrocarbon contamination has been detected in the groundwater beneath the Admiralty Oil Reservoir No4 it will be necessary for the Operator to ensure that the pathway from this reservoir to the groundwater beneath is identified and sealed during the construction phase of the development. As a result part of the response to Pre-operational condition POC3 requires the Operator to detail an investigation into identifying this pathway and ensuring that it is sealed to avoid any further migration of hydrocarbon from the Admiralty Oil Reservoir No4 into underlying groundwater.
C7 Emissions to water, air or land.
Permit condition 3.1 1. Emissions to air.
(a) BAT assessment of Abatement techniques. (i) Particulates
The Applicant states that the diesel compression ignition engines
employed at the site will have a manufacturers guarantee that particulate emissions will be below 50mg/Nm3. The relevant UK technical guidance note indicates that 50mg/Nm3 is considered BAT for particulate emissions from such engines. Additional reduction in particulate emission could be achieved by use of abatement techniques such as Electrostatic
precipitation and/or bag filters.
We agree with the Applicant that such additional abatement cannot be justified as BAT as :
• the process contribution for particulate (assuming worst case that all particulate emissions classify as PM10) from the site is predicted by
modelling to be below 1% of the relevant air quality standard for all receptors apart from two where the short-term process contribution may increase to 5% of the relevant air quality standard.
• High construction and operational costs of abatement cannot be justified as there is no driver to lowering the process contribution of particulate further.
(ii) Oxides of nitrogen
Unabated emissions of oxides of nitrogen (NOx) from the compression ignition engines are predicted to be at a concentration of 2000mg/Nm3. The ambient air in Gibraltar is already failing to meet the annual average European Air Quality Objective limit of 40µg/m3 for annual average of nitrogen dioxide based on the Rosia Road ambient air monitor. A
significant percentage (~50%) of the ambient NO2 in this area results from
the operation of the three power stations currently operating in Gibraltar. All three will be decommissioned when the Lathbury Barracks power station becomes operational. Therefore, the process contribution of the existing power stations is not considered in our determination of the Lathbury Barracks power station PPC permit application.
Unabated emission of NOx (estimated at 2000mg/Nm3) would lead to a significant additional loading of nitrogen dioxide in ambient air in the area. Therefore, it is necessary to place post-combustion abatement to the gas engines in respect of NOx.
The Applicant has indicated that they will install a Selective Catalytic Reactor (SCR) system to reduce the concentration of oxides of nitrogen released from the plant by at least 80%. The Applicant indicates that the SCR will be used to reduce levels by 80% to 400mg/Nm3 during Phase I of the project (2011 – 2032) and then by 90% to 200mg/Nm3 when Phase II is complete.
The IPPC Directive and the PPC Regulations under which this permit is issued requires that the impact on the environment is minimised as far as possible without entailing excessive cost.
Therefore, we required the Applicant to justify why they were proposing to reduce NOx emissions to 400mg/Nm3 whilst operating nine engines only and reducing to 200mg/Nm3 emissions when twelve engines become operational.
The Applicant has calculated that if NOx emissions were to be reduced to 200mg/Nm3 rather than 400mg/Nm3 when operating with nine engines then the cost of electricity produced would increase by 3.1%. The increase to cost of electricity production during the 20 year lifetime of the power station would be 3.3%.
Electricity generation in Gibraltar is a government run facility which is run on the basis of ‘breaking even’. Therefore, any additional costs in
electricity production must be directly passed onto the consumer. Based on initial electricity output the Predicted Environmental
Concentration for annual mean NO2 is below 70% of the the relevant AQS even at an emission rate of 400mg/Nm3 for NOx. Therefore, we have decided to set the limit at 400mg/Nm3 but require the Applicant
(Improvement Condition IP1) to assess whether a further reduction in NOx emission concentrations are required as the power station increases its electrical output.
(iii) Sulphur dioxide
The Applicant states that the fuel used in the compressed ignition engines will be distillate fuel oil. This will have a sulphur content of less that 0.1% in line with the Sulphur in Liquid Fuels Directive. The concentration of sulphur dioxide within the emissions from the compressed ignition engines is dependant on the sulphur content of the fuel Other than gaseous fuels distillate fuel oils have the lowest sulphur content and therefore use of this fuel is considered BAT for minimising emissions of sulphur dioxide in areas such as Gibraltar where a natural gas supply is not available. A sulphr content in the fuel of less than 0.1% will limit sulphur dioxide emissions to below 44mg/Nm3. This is within the indicative BAT limit quoted within the relevant technical guidance note. A limit of 50mg/Nm3 is set on the permit to allow for testing and sampling errors. No additional abatement is considered necessary as the sulphur dioxide emissions are controlled to a low level by choice of fuel and the process contribution of the emissions to ambient levels of Sulphur dioxide is very low.
(iv) Carbon monoxide
Carbon monoxide emissions from the power station are minimised by ensuring effective combustion by using excess air and good fuel/air mixing. The predicted emissions of carbon monoxide are within the indicative BAT levels and a limit has been set of 100mg/Nm3 which is at the lower end of the indicative BAT range of emission concentrations. Carbon monoxide readily converts to carbon dioxide in excess air and as a result only a short-term Air Quality Standard exists for this pollutant. At the emission level set the process contribution to short-term ambient levels of carbon monoxide are very small compared with the relevant Air Quality Standard.
(b) Predicted emissions
The following table indicates the predicted emission concentrations based on the proposed abatement techniques for emissions to air
.
Pollutant Predicted emission concentration (mg/Nm3)
Particulate (PM10) 50
Oxides of nitrogen 400 (80%SCR)(reducing to 200 in 2032(90% SCR))
Sulphur dioxide 44
Carbon monoxide 100
(c) Emission Limit Values.
The averaging periods for reporting continuous emissions of the combustion gases are in line with the averaging periods required within the Large
Combustion Plant Directive.
The following table gives a comparison of indicative BAT for liquid fuelled compression ignition engines as stated within the Technical Guidance Note –
IPPC Technical Guidance Note Combustion Activities v2.03 dated 27.07.05 and the emissions limit values set within the permit.
Pollutant Indicative BAT (mg/Nm3) Emission limit value (mg/Nm3) Carbon monoxide 100 - 150 100 Sulphur dioxide 66 50 Oxides of nitrogen 150 200 Particulate 50 50
All limits set on the Permit are at indicative BAT levels with the exception of sulphur dioxide and oxides of nitrogen.
The sulphur dioxide emissions are controlled by the sulphur content of the fuel used. The Applicant has indicated that the sulphur content of the fuel will be below 0.1% w/w in line with the Sulphur in Liquid Fuels Directive. This therefore means that emissions of sulphur dioxide will remain below 44mg/Nm3.
Therefore, the emission limit value of 50mg/Nm3 should be routinely achieveable and is set to ensure that the fuel used conforms with the Sulphur in Liquid Fuels Directive.
The UK combustion technical guidance note considers that if Combustion Ignition engines operate to BAT then a NOx emission concentration of 150mg/Nm3
should be achieveable. This level of NOx emissions is based on the use of Selective Catalytic Reduction (SCR) abatement. GibElec are proposing to use SCR at the Lathbury Barracks site. Information from the suppliers of the combustion engines to be used at the Lathbury Barracks site indicate that the unabated oxides of nitrogen emissions from these engines will be at a
concentration of 2000mg/Nm3. Selective Catlaytic Reduction (SCR) techniques can practically lower the emissions of oxides of nitrogen from a facility by 80 – 90% with associated costs increasing exponentially with percentage reduction. The applicant indicates that an 80% reduction is sufficient to protect the
environment when operation start at the site and NOx emissions are relatively low. However, it is recognised that as the output of the power station increases then a greater % decrease in generated NOx will be required in order to continue to offer sufficient environmental protection. Therefore, a limit of 400mg/Nm3 is set for NOx based on the initial predicted power station output and improvement condition IP1 is set to consider when it will be necessary to increase the dosage of SCR reagents to increase the percentage reduction in generated NOx. The limit set in Table S4.1 of the permit is subject to change based on the response to improvement condition IP1.
Pre-operational condition POC5 requires the Operator to optimise the use of SCR during the commissioning period. The results of this optimisation will enable the Operator to optimise their usage of SCR reagent and minimise waste. The emission limits for particulate and carbon monoxide are set at indicative BAT as there is no driver to set a lower limit as none of the applicable air quality standards are at risk from the process contribution to ambient levels by the proposed power station.
2. Emissions to controlled waters
There are no emissions to controlled waters. However, all the surface water from the site is emitted to the environment via a cliff outfall into the Mediterraean Sea. The surface water from non-operational areas of site is discharged directly to this outfall whereas the surface water from
operational areas of site is discharged to the outfall via an oil interceptor. The Permit requires that the water leaving the interceptor is sampled weekly (24-hour proportional sample) for oil and suspended solids. This will enable the Operator and the Environmental Agency to monitor the efficiency of the interceptor and ensure that it continues to be maintained appropriately.
3. Emissions to sewer
The only emissions to sewer is the periodic discharge of waste water from the closed cooling system. This is discharged to sewer via an oil
interceptor.
4. Emissions to land.
There will be no emissions from the facility direct to land.
5. Health Risk Assessment.
The Environmental Impact Assessment for the power station compares the process contribution of NOx emissions from the Lathbury Barracks power station to the combined impact of the three existing power stations on Gibraltar at several human receptor locations. NOx emissions contribute to ambient levels of NO2 and Gibraltar town has recently routinely failed to
meet the NO2 annual average EU Air Quality Objective limit of 40µg/m3.
The new power station at Lathbury Barracks will be located above the town, further up the rock and as such will have a reduced impact on the levels of NO2 in ambient air in the residential areas of Gibraltar. The Applicant has modelled the combined impact of the current power stations at 20 different human receptor locations and further modelled the predicted impact of the new power station on these locations.
The Applicant has modelled the annual average values based on an average output of 26.1MWe for 2011 and 38.8MW for 2032. Hourly average process contributions have been modelled at an output of 50.4MWe in 2011 and 72MW in 2032. The hourly average should be modelled at peak loads. In the response to additional information
requested received on 28 September 2009 the Applicant indicated that the peak load for 2011 was predicted to 41MWe and for 2032 this was
predicted to rise to 67MWe. Therefore the short-term modelling work carried out has been based on a higher peak and will be conservative in nature. Both 2011 and 2032 data is based on 80% NOx reduction by SCR. Table C1 below indicates the change in power station(s) process
contribution to NO2 ambient levels at the human receptors modelled. As the permit limits are based on a reduction of 80% in generated NOx then the results for 2032 have been adapted to reflect process
contributions on 80% reduction. The Applicant’s data for this period was based on 90% reduction. The data in Table C1 indicates that as power
station output increases towards 2032 the process contribution to short-term Air Quality Standard for NOx increases to above 70% in areas closer to the new site including HM Prison and the Retirement Home. The process contribution to annual average in the same area exceeds 8% of the relevant Air Quality Standard at this time. As a result improvement condition IP1 has been added to the permit to require the Applicant to consider when it will be necessary to increase the percentage reduction in generated NOx to adequately protect the environment. Pre-operational condition POC1 is also added to gather ambient air quality data to use as the basis for the assessment in improvement condition IP1.
25
Table C1 : Comparision of process contribution to ambient levels of NOx pre-2011, 2011 and post 2032.
Process contribution of power station(s) (µg/m3)
Hourly average Annual average
2011 2032 2011 2032
Ref. Location Existing
New Difference New Difference
Existing
New Difference New Difference
H1 Clifftop House 81.5 121.4 39.9 163.4 81.9 1.29 0.84 -0.42 1.3 -0.46
H2 The Retreat Centre 93.8 94.2 0.4 129.6 35.8 1.32 0.68 -0.64 1.1 -0.22
H3 Retirement Home 110 114.8 4.8 177.6 77.6 1.05 1.8 0.75 3.2 1.4
H4 HM Prison 144 96.0 -48 141.4 -2.6 1.25 2.6 1.35 3.8 1.2
H5 Windmill Hill Road 273 58 -215 84.0 -189 2.33 0.32 -2.01 0.46 -1.87
H6 Royal Naval Hospital 273 43.8 -229.2 68.4 -204.6 3.54 0.28 -3.26 0.40 -3.14
H7 Community Catholic Centrel 167 11.8 -155.2 17.2 -149.8 1.99 0.12 -1.87 0.18 -1.81
H8 South View Terrace 265 17.4 -247.6 28.8 -236.2 6.20 0.14 -6.06 0.20 -6.0
H9 St. Joseph’s School 1250 17.4 -1232.6 28.2 -1221.8 14.1 0.12 -13.98 0.20 -13.9 H10 Nuffield Pool 23.7 33.2 9.5 34.2 10.5 0.87 0.38 -0.49 0.56 -0.32 H11 Public Terraces 46.5 33.4 -13.1 52.8 6.3 1.71 0.30 -1.41 0.44 -1.27 H12 St. Christopher’s school 33.0 34.0 1 48.6 15.6 1.06 0.20 -0.86 0.28 -0.78 H13 Rosia Road 5450 16.4 -5433.6 23.8 -5426.2 560 0.10 -559.9 0.16 -559.84 H14 Withams Road 5420 14.6 -5398.1 23.2 -5396.8 637 0.10 -636.9 0.16 -636.84
H15 Red Sands Road 6740 15.4 -5405.4 21.4 -6718.6 537 0.10 -536.9 0.16 -536.84
H16 Governors Meadows Estate 5690 13.4 -5676.9 19.6 -5670.4 427 0.10 -426.9 0.14 -426.86
H17 Harbour Views 352 6.2 -345.8 11.0 -341 5.15 0.04 -5.11 0.14 -5.05
H18 Sir William Jackson Grove 1470 7.0 -1463 11.0 -1459 13.8 0.04 -13.76 0.06 -13.74
H19 Varyl Beg Estate 746 7.0 -739 11.4 -734.6 7.43 0.04 -7.39 0.06 -7.37
6. Habitats assessment.
The Environmental Impact Assessment for the power station compares the process contribution of NOx emissions from the Lathbury Barracks power station to the combined impact of the three existing power stations on Gibraltar at several ecological locations within the SCI. NOx emissions contribute to ambient levels of NO2 which leads to nitrification of the
Habitat region and potential subsequent damage. For the purposes of the Application and in the absence of monitoring data it has been assumed that current ground level concentrations of NO2 at the Habitat are 40µg/m3.
This assumption appears conservative as diffusion tube monitoring in the area has indicated that areas closer to the SCI and the power station site have an NO2 level of about 30µg/m3 with the higher annual averages of up to 60µg/m3 occuring more than 1km to the west of the SCI in the
immediate proximity of the existing power stations. NO2 has an ecological
Air Quality Objective of 30µg/m3, but this is not relevant within 5km of an A(1) listed activity under the PPC Regulations. Due to its geography all areas of Gibraltar are within 5km of the current power station, therefore, the relevant Air Quality Objective limit is 40µg/m3 as an annual average. Table C2 below indicates the change in power station(s) process
contribution (as modelled) to NO2 ambient levels at a number of points
within the SCI and within close proximity of the site of the new power station.
The Applicant has modelled the combined impact of the current power stations at 8 different ecological receptors and further modelled the predicted impact of the new power station on these receptors. The Applicant has modelled the annual average values based on an average output of 26.1MWe for 2011 and 38.8MWe for 2032.
The contribution of emissions from the power stations to hourly averages of NOx has not been carried out for ecological receptors as it is the long term nitrogen levels that are critical in respect of impacts on ecological receptors.
As above for the human receptors the contribution for 2032 has been adjusted to be based on 80% NOx reduction by SCR rather than 90%, in line with the issued Permit requirements. The data submitted in the Application for 2032 was based on a reduction of 90%.
Receptors E4 to E8 are located at the southern edge of the Lathbury Barracks site.
E1 and E2 are located at the Southern edge of the SCI north of the site, whereas E3 is located to the west of the site at the northern tip of the SCI to the south of the site.
All of the ecological receptors modelled with the exception of E1 to the north east of the site are subject to a reduced process contribution to ground level concentrations of NOx/NO2 as a result of power station
Table C2 : Comparision of process contribution to ambient levels of NOx Process contribution of power station(s) (µg/m3)
Annual average
2011 2032
Ref. Direction from site of new
power station Existing
New Difference New Difference
E1 North East 1.05 4.96 3.91 7.6 6.55
E2 North East 3.14 1.2 -1.94 1.7 -1.44
E3 West 2.33 0.2 -2.13 0.24 -2.09
E4 South West 1.54 0.06 -1.48 0.08 -1.46
E5 South south west 1.60 0.02 -1.56 0.02 -1.58
E6 South 1.74 0.02 -1.70 0.02 -1.72
E7 South south east 2.10 0.02 -2.06 0.02 -2.08
E8 South east 4.23 0.02 -4.21 0.04 -4.19
As the development of the Lathbury Barracks power station will enable the exisiting power stations to be decommissioned the process contribution to ambient levels of NOx at the ecological receptors will generally be reduced (with the exception of E1) as a result of the Lathbury Barracks power station coming on line. Ambient levels of NO2 in this area have been
measured as 26µg/m3 and therefore even the addition of up to 8µg/m3 process contribution from the power station to NO2 levels would not increase the levels at the Habitat above the Air Quality Standard of 40µg/m3. Therefore, the emissions to air from the facility would not in themselves be expected to cause an adverse impact of the site’s integrity. However, there is concern that other aspects of the development such as noise may interfere with the movement of some species from the southern part of the SCI to the northern part. The Lathbury Barracks site lies on non-SCI ground inbetween the two Habitat areas.
An appropriate assessment has being carried out by the Department of the Environment. This has indicated that the noise, light and physical barrier created by the new power station may lead to an adverse effect on site integrity by interfering with the natural movement of species from the southern part to the northern part of the SCI. The planning authority have determined that the power station should be granted permission despite the potential impact on site integrity of SCI on the grounds of Overriding Public Interest.
C8 Fugitive emissions of substances
Permit condition 3.3 Based upon the information we are satisfied that the appropriate infrastructure will be put in place to minimise as far as possible fugitive emissions. Condition 3.3.1
requires this fugitive emissions management plan to be reviewed and updated on a periodic basis and/or as a result of any incidents resulting from the release of fugitive emissions.
C9 Conditions relating to Odour
Permit condition 3.4 Based upon the information in the application we are satisfied that the appropriate measures will be in place to prevent annoyance from odour. There are few odour sources on site and all potentially odorous substances such as the distillate fuel oil and stored within enclosed systems. The Operator within the Application indicates that odour due to fugitive emissions of distillate fuel oil as a result of tank loading will be kept to a minimum by use of de-misters.
Condition 3.4.1 of the permit requires the Operator to control odours at the site so that they do not cause annoyance beyond the site boundary.
C10 Noise and vibration
Permit condition 3.5 Based upon the information in the application we are not fully satisfied that the
appropriate measures will be in place to prevent annoyance as a result of noise and vibration at the site. Therefore, pre-operational POC7 has been set to require the Operator to submit a Noise management plan including noise modelling based on the sound power levels of the equipment selected at the site. This will enable the
Environmental Agency to determine whether complaints are likely results from annoyance caused by noise and vibration from the site. Pre-operational condition POC5 requires the Operator to inform the Environmental Agency how the noise impact of the site will be verified after start-up and put agreed noise monitoring in place during the commissioning period to assess the efficiency of the noise management plan and accuracy of the noise modelling undertaken.
Condition 3.5.1 of the permit requires the Operator to control noise at the site so that it does not cause annoyance beyond the site boundary.
C11 Monitoring
Permit condition 3.6 .
We have decided that monitoring should be carried out for the parameters listed in tables S4.1 and S4.2 in schedule 4 using the methods and to the frequencies specified in those tables.
Continuous monitoring is required for particulate, oxides of nitrogen, sulphur dioxide, and carbon monoxide in line with the requirements of the Large Combustion Plant Directive.
For each of these parameters an annual spot monitoring sample is also required. This spot sample may also be used to calibrate the continuous monitors.
Quarterly spot sampling is required for ammonia to demonstrate that the SCR plant is controlled effectively limiting ammonia slippage. Ammonia will also contribute to nitrification of the surrounding Habitat and therefore need to be minimised.
Based on the information in the application we are satisfied that the operator’s techniques, personnel and equipment will have either MCERTS certification or MCERTS accreditation as appropriate.
C12 Reporting
We have specified reporting as specified in Schedule 5 based on the frequency of monitoring.
In the case of continuous monitoring reporting is required on a quarterly basis whereas for periodic spot monitoring reporting is required on an annual basis.
