MEMORANDUM

DATE: 30th April 2003 TO: Each Board Member FROM: Mary Gurrie RE: Submission on application for IPC licence from Electricity Supply Board, Bellacorick Generating Station, Bellacorick, Ballina, (Reg. No. 627)

Application Details Classes of activity: 2.1 – The production of energy in combustion plant the rated thermal input of which is greater than 50MW 11.1 - The recovery or disposal of waste in a facility, within the meaning of the Waste Management Act, 1996, which facility is connected or associated with another activity specified in this Schedule in respect of which a licence or revised licence under Part IV is in force or in respect of which a licence under the said Part is or will be required. License application received: 17/12/01 Notices under article 11(2)(b)(ii) 8/2/02, 2/8/02 issued: Information under article 11(2)(b)(ii) 2/5/02, 9/5/02, 7/6/02, 27/6/02, 1/10/02, 8/11/02, 27/11/02, received: 24/1/03, 23/4/03

COMPANY Bellacorick Generating Station is situated in Bellacorick, Co. Mayo between and Bangor . The total site area is 38 hectares. There are two identical units on site, the first was commissioned in 1962 and the second in 1963. Since commissioning the plant has operated mainly on base load (continuous operation). Peat is the primary fuel with approximately 270,000 tonnes consumed per annum. 65% of the peat used is transported by rail; the remainder is brought by lorry from . There are currently 75 employees on site.

Under a tripartite agreement between the government, ESB and the unions, Bellacorick generating station is due to close by the end of 2004. In the recent past single unit operation has been the norm due to limited supplies of suitable quality milled peat. This situation is likely to continue until plant closure.

The current plant performance for each unit is • Gross output at generator terminals: 20MWel • Auxiliary power demand: 6-7% • Plant net efficiency: ca. 25%.

PROCESS Each generating unit consists of a peat fired natural circulation drum boiler with superheater supplying steam to a 3000rpm radial steam-condensing turbine. The turbine drives an air cooled generator sending electrical power to the national grid. The units can fire on light fuel

l:\licensing unit\licence determination\ippc\licence decisions\p0627\627insprept.doc 1 oil during periods of start-up and for combustion support. The water/steam system is a closed circuit with make up water from the Owenmore River being added to cater for system losses. Cooling water from the cooling tower is used to extract the heat from the low temperature steam at the turbine exit. Ash from the boiler is disposed of in the on-site ash disposal facility. The main features of the station include: • Station main building housing boiler and turbo-alternator units • Fuel bunkers capable of storing 700 tonnes of peat • Fuel handling system • Oil and diesel storage tanks • Cooling water system • Water treatment plant • Ash handling system and disposal areas • Two reinforced steel chimneys, each 45.7m in height • Generator transformers and 100kV switch gear compound

Resource Consumption The principle resources that will be used are as follows: Fuel – peat is the primary fuel (270,000tonnes per annum). Light fuel oil is used for start- ups and combustion support (ca. 3000t of LFO per annum). Water – water is abstracted from the Owenmore River at a maximum rate of 0.16m3/s. Total water usage is approximately 600m3 per day. Chemicals – bulk chemicals are used for boiler water conditioning and re-generation of de- ionising plant resins – these are principally hydrazine, sodium hydroxide and sulphuric acid. Other chemicals in small quantities are used for standard laboratory testing and other purposes. Electricity – about 6-7% of electricity produced is used for in-house load

Ash handling and disposal Approximately 10,000 tonnes (dry basis) of ash are produced annually. There are two types of ash, both of which are considered non-hazardous under the European Waste Catalogue – furnace bottom ash (FBA) which is collected in a hopper at the bottom of the furnace and pulverised fly ash (PFA) collected in hoppers at the bottom of the grit-arrestors. Water driven ejectors carry the ash via a pump house to the ash disposal pond (ADP). Dry fly ash collected prior to the grit arrestors largely comprises grit, stones, etc and amounts to a further 800tonnes annually. It is disposed of in the dry ash disposal facility (DADF). Other previously used ash disposal areas are now grassed over. Overall 500,000tonnes of ash has been disposed of on-site.

PROPOSED DETERMINATION

LEGISLATION: IPPC Directive As an existing activity, the IPPC Directive will apply by 30/10/2007.

Large Combustion Plant Directives (2001/80/EC) A first draft of the Large Combustion Plant BREF was issued in March 2001 and a second draft issued in March 2003. In the absence of a final document the requirements for ‘existing’ plant under the LCP directive 2001/80/EC are considered to represent BAT/BATNEEC.

Landfill Directive (96/61/EC) As required under the landfill directive the applicant submitted a conditioning plan for the ash landfill by 16/7/02. Condition 7.2 of the PD includes the necessary requirements.

2 AIR Air Emissions The emissions requested in the application and the ELVs required under the LCP directive are as follows:

3 Each boiler is rated at 74MWth input (20MWel output). Values are given as mg/Nm dry gas at 6% O2. Parameter Emissions as per ELVs from LCP directive application From 1/1/2008 Note 2 peat oil Note 1 Oxides of sulphur (as SO2) 1980 2000 1700 Nitrogen oxides (as NO2) 300 600 450 Particulates 1100 100 50 3 Note 1: SOx emissions are estimated at 2200mg/m based on the average S content of peat (0.8%). A 10% allowance is made for sulphur retention in ash. Note 2: Existing plants may be exempted from compliance with these emission limit values if they undertake in writing not to operate for more than 20,000 operation hours starting from 1 January 2008 and ending no later than 31 December 2015.

Emission Limit Values and appropriate exemptions as per the LCP directive have been applied in Schedule 1(i) Emissions to Atmosphere of the PD.

Air Impact Modelling of the maximum ground level impact of the discharge was carried out using five years meteorological data based on both boilers firing at full load. The results can be summarised as follows: Parameter Modelled Impact Modelled Comparison AQS (µg/m3) Conc. (µg/m3) NO2 (assumes 99.8%ile of hourly values 92 200 (S.I. 271 of 2002) 60% NOx 98%ile of hourly values 70 200 (S.I. 244 of 1987) converts to Highest annual mean 5.7 40 (S.I. 271 of 2002)1 2 NO2) 30 (as NOx, S.I. 271 of 2002) SO2 99.7%ile of hourly values 1002 350 (S.I. 271 of 2002) 99.2%ile of daily values 426 125 (S.I. 271 of 2002) 98%ile of Daily values 394 250-350 (S.I. 244 of 1987)3 Median of daily values - 80-120 (S.I. 244 of 1987)4 Highest annual mean 63 20 (S.I. 271 of 2002)5 Particulates 98%ile daily values 215 250 (S.I. 244 of 1987) 6 PM10 90.4%ile of daily values 42 50 (S.I. 271 of 2002) 98.1%ile of daily values 61.5 50 (S.I. 271 of 2002)7 Annual Mean 12.5 40 (S.I. 271 of 2002) Dust Average deposition rate 781 350 (TA Luft) (mg/m2/day) 1. Limit for protection of human health. 2. Limit for protection of vegetation. 3. Limit value of 350 µg/m3 applies when corresponding percentile of total particulates is ≤ 150 µg/m3; otherwise the limit of 250 µg/m3 applies. 4. Limit value of 80 µg/m3 applies when corresponding median of total particulates is ≤ 40 µg/m3; otherwise the limit of 120 µg/m3 applies. 5. Limit value for protection of ecosystems, calendar year and winter (1 October to 31 March). 6. To be met by 1/1/2005. 7. To be met by 1/1/2010.

Air dispersion modelling carried out for the application predicts that in a worst case scenario with both units running continuously, air quality standards for SO2 would not be fully complied with and dust deposition rates could exceed TA Luft guideline values. Ambient

3 dust monitoring over many years indicates substantial model over prediction (by a factor of 3- 6 fold). Condition 5.15 requires on-going monitoring of dust around the site. Modelling predicts that the 90.4 percentile for PM10 can be met; however the 98.1 percentile for PM10, which must be met by 2010, may be breached. Given that the model over predicts dust and that the plant is expected to close during 2004 this is unlikely to be a problem, however provision for the plant’s extended operation is included in the PD and Condition 5.16 requires st continuous ambient monitoring of PM10 from 1 January 2005.

Continuous ambient SO2 monitoring carried out during December 2002-February 2003 indicates generally low levels of SO2 (average concentration of SO2 for the period is 4.4µg/m3), however ambient hourly concentrations occasionally exceed 200µg/m3 during single unit operation. In order to ensure that ambient SO2 limits are not exceeded Condition 5.17 allows only one unit to be operated at a time except during periods of changeover. In addition, Condition 5.14 requires continuous ambient SO2 monitoring to be carried out within one month of date of grant of licence. If the ambient SO2 limits are breached then the licensee will be required to take whatever measures are necessary to reduce the SO2 emission levels. Such measures may include the shut down or reduction of on-site processes.

There are no other major emissions to atmosphere. Minor emissions include a diesel fire pump hydrant system which is tested for 15 minutes every week. Estimated diesel consumption is 0.5t/a.

WATER Process Water Water for use in the boilers is abstracted from the Owenmore River. Treatment includes precipitation, filtration and demineralisation using ion exchange resins. The ion exchange units are regenerated up to 3 times per week using sulphuric acid and sodium hydroxide. This results in alternate acidic and basic waste streams which discharge in combination to a settlement pond to allow neutralisation prior to discharge to the Oweninny river (at SW1).

Cooling water is stored in the cooling tower in a closed system. It circulates through the condenser tubes condensing the steam then flows through discharge culverts and back to the cooling tower. The heated water gives up its heat in the cooling tower as it counterflows and contacts with an upward circulation of ambient air. The cooling tower contains approximately 4550m3 of untreated water. Losses amount to 10% per day and so make up from the Owenmore River is typically around 500m3/day (the dry weather flow in the Owenmore River is 172,800m3/day). The cooling tower is chlorinated once a year during the annual outage, allowed to sit over night and then is discharged via the main station settlement pond to the Oweninny River over a two day period at a chlorine concentration less than 0.1ppm. The water used in the ashing system and the band screen wash is drawn off from the cooling tower outlet.

Emissions to water There are 7 separate emissions to water: SW1(A,B,C and D), SW5A and SW6 discharge to the Oweninny River while SW2, SW3, SW4 and SW5 discharge to the Owenmore River. The Oweninny River combines with other tributaries to become the Owenmore River which flows west/southwest to enter the sea at Tullaghan Bay. Both rivers are generally considered to have a moderate to high assimilative capacity. The Owenmore River system is a renowned salmonid river.

SW1 comprises 4 streams – engine room/boiler house drains (A), water treatment effluent (B), boiler blowdowns (C) and surface water run-off (D). Currently these combine in the main station settling pond and pass through an oil interceptor prior to discharge. ELVs have been set at either the individual streams prior to dilution or at the combined discharge as appropriate. Condition 6.4 of the PD requires the surface water drain SW1/D to be diverted

4 from the settling pond. Blowdown water contains phosphate and ammonia. Residence time in the blowdown tank, settling pond and oil-interceptor leads to a reduction in temperature to ambient conditions.

SW2 consists of water diverted from the cooling water system and is used as screen wash at the water abstraction pumphouse.

SW3 is the discharge from the PurafloTM sewage treatment plant which serves 75 people. The system achieves an effluent standard of 5-7mg/l BOD and 10mg/l suspended solids.

SW4 is the cooling tower overflow. Water is discharged intermittently, particularly during the summer months when incoming water is hard. The cooling tower is chlorinated using sodium hypochlorite (approx. 700l) once per year to less than 0.1ppm. This is left over night and then released over a two-day period via the main station settlement pond to the Oweninny River.

SW5 is the ash pond run-off under normal operation. Ash is pumped to the ash disposal area which consists of main and reserve settling ponds. The supernatant liquid flows via a series of ponds and drains to the outfall. The volume of the discharge is approximately 180m3/h and the pH is in the range 6-9. Suspended solids concentrations are generally below 30mg/l. These limits have been conditioned in the PD.

SW5A is the ash pond run off when it is diverted from SW5 while cleaning is on going. SW5 and SW5A never discharge at the same time.

SW6 comprises surface water run-off.

All of the above discharges are conditioned under Schedule 2(i) and Schedule 2(iii) of the PD. The applicant has a licence under the Local Government (Water Pollution Act) 1977 to discharge domestic sewage effluent to the Owenmore River and specifying conditions relating to other discharges on site. Results of ambient monitoring for all relevant parameters carried out over a number of years indicates that the water quality of the rivers close to the plant is not being significantly negatively impacted by the generating station.

List I and List II substances Four substances, which are considered List II substances, are utilised for water treatment as indicated below. • Sodium hypochlorite (chlorine) is used to treat the cooling water • Hydrazine, a probable human carcinogen, is used as an oxygen scavenger in the boiler water. • Ammonia is utilised for boiler treatment • Trisodium phosphate is used to treat boiler water

A requirement to either substitute or reduce these substances has been scheduled under Items to be Addressed when Establishing the Schedule of Objectives and Targets.

Groundwater An environmental investigation of the geology and hydrogeology of the site was carried out in 1996 and monitoring was repeated in 1997, 1998 and 2001. The site is overlain by a highly variable sequence of grey-brown silty sands, brown-grey sandy silts and soft brown peat. This is overlain locally, in former waste disposal areas by a black sandy ash. The former waste disposal areas are underlain by poorly sorted silty sand with a relatively low permeability. The GSI defines the sand and gravel deposits as a regionally important, high

5 vulnerability major aquifer. However, the overlying low permeability sandy silts and peat would reduce the vulnerability beneath Bellacorick to moderate/high. In addition attempts to sink water wells on site have been unsuccessful with limited quantities recovered which suggests that the gravel horizon is, at least locally, unproductive and unlikely to be used as a significant water resource. The groundwater flows towards and into the Owenmore and Oweninny rivers.

The most recent (2001) groundwater monitoring survey indicates widespread contamination with respect to ammoniacal nitrogen, total coliform and manganese. The applicant attributes this to naturally high background levels, except in the case of two boreholes located near to septic tanks. Condition 9.3.10 requires an investigation into the condition of the tanks and pipelines associated with the on-site sewage treatment facilities within 6 months of date of grant of licence. Boreholes BH8 and BH9 beside the main station settling pond (and former waste disposal area) indicate elevated levels of iron, mineral oil and ammonia (up to 12.3mg/l). Condition 9.2.5 requires an investigation in to the source of contamination in this area. Boreholes adjacent to the current and former ash disposal ponds indicate elevated conductivity and alkalinity with respect to background levels and, in the case of one borehole, elevated magnesium (260 vs. 50mg/l) and sulphate (260 vs. 250mg/l) with respect to drinking water standards. These levels of contamination are relatively low and not of particular significance. Contaminant transport modelling was used to simulate the migration of SO4 from the ash pond to the river. Results indicate that levels in the groundwater at the Owenmore and Oweninny rivers will be below statutory limit values and river samples downstream of the station suggest that any contaminants are quickly diluted to background levels. Groundwater monitoring is required biannually under Schedule 4(ii).

WASTE Other than ash which is landfilled on-site, wastes are sent off-site for disposal/recovery. The principle materials are scrap metals, waste oil, interceptor sludges, sewage sludges and general waste. Condition 7 of the PD deals with all waste disposal.

Historic Waste disposal areas On-site disposal of most station waste was carried out until 1995. Items disposed of in the former ash disposal areas include batteries, ion exchange resins, canteen waste, sewage sludge, oil filters, containers for chemicals, oil interceptor sediments, fluorescent tubes and lamps, oil-contaminated materials, degreasing solvents, paint tins etc. The waste disposal area was bulldozed occasionally and the level of an adjacent, privately owned field was raised in a similar manner at the request of the owner. This area has been grassed over for many years and part of it planted with trees. Prior to 1984 unbagged asbestos was disposed of in unknown locations on site. From 1984 a record was kept of waste disposal areas and a number of permits were received subsequently for disposal of asbestos waste on-site. A programme is currently underway to locate and remove any potentially hazardous wastes including asbestos from the two historic dump areas on site. A report detailing the investigation is required under Condition 9.3.12.

Investigations have shown significant difference in the soil chemistry between the material in the station dumps and the underlying silty sand. This suggests that little, if any, leachate from the dump material has contaminated the underlying sub-soil. The appearance and chemistry of the dump material suggests that the majority is peat ash. However traces of mineral oil have been detected within the dump material suggesting that some oil could have been locally co-disposed with it. Condition 9.2.5 deals with contamination in this area.

A sample of peat ash taken from the former main ash settling pond during its operation showed elevated levels of a number of substances (calcium, iron, sulphate, arsenic, cadmium, chromium, copper, lead, mercury, nickel and selenium). However the leachability of this

6 material appeared to be low as the supernatant liquid only showed elevated sulphate, calcium, selenium, molybdenum and pH and as discussed above groundwater does not appear to have been significantly affected.

NOISE The site is situated immediately north of Bellacorick village which consists of a number of private dwellings and a public house. Noise monitoring carried out at the three nearest noise sensitive locations, NSL1, NSL2 and NSL3 (at 95m, 155m and 700m distance from the main station buildings respectively) indicate sound pressure levels in exceedance of BATNEEC limits at one location, NSL1, with Leq(30 minutes) of 58.0dBA during daytime and Leq(15 minutes) of 55.8dBA at night-time. The corresponding LA90 values are 52.7 and 49.2 respectively. It should be noted that noise measurements were taken during periods while one unit was operating on full load and there was some contribution from other sources. The applicant states that there are no clearly audible tonal or impulsive noises at night and no complaints regarding noise during daytime or night-time have been received. A daytime limit of 55dBA has been set and a night-time limit of 45dB(A) from 1/1/05 with a limit of 47dB(A) applying until then. A programme to reduce noise is included in items to be addressed in the Schedule of Objectives and Targets.

GROUND Ash Results of solid ash analyses from peat-fired power stations indicate the ash is alkaline and that the majority of the determinants are within their typical soil range analysis. Determinants which exceeded either the Dutch ‘S’ or ‘I’ levels are calcium, cadmium, copper, selenium and arsenic. The alkaline nature of the ash inhibits the mobilisation of metals from insoluble forms and thus prevents their migration to waters in leachate.

Ash leachate samples were found to be highly alkaline, with elevated conductivity, total dissolved solids (TDS) and sulphate concentrations. Most other determinants were below EU drinking water or surface water limits. Parameters exceeding these standards include total cyanide, ammonia, barium, selenium, potassium and phosphate. Results of groundwater monitoring over a number of years however does not indicate a significant impact from the on-site landfills. Ash disposal is controlled under Condition 7.2 of the PD and groundwater monitoring is required biannually as per Schedule 4(ii).

Toxicity testing on ash leachate samples from three power stations (Shannonbridge, Lanesboro, Edenderry Power) was carried out. Results are shown below.

Test Daphnia magna Lemna minor Vibrio fischeri 48hr EC50 7 day IC50 5min EC50 15min EC50 Range of results (TU) 18.2-21.9 <10 125-167 143-167

The elevated toxicity is most likely due to the high pH of the leachate. It is stated that owing to a series of reactions calcium carbonate forms a seal around the base and sides of the ash disposal areas. The pH of the groundwater in the area is less that 8 and the pH of the ash pond run-off is typically less than 9. Condition 6.8 requires toxicity testing of the ash pond run-off at SW5.

Other than the on-site ash disposal system, emissions to ground consists of a single toilet which discharges to a Puraflo treatment system and soak-away.

NHAS/SACS Designated sites in the vicinity of the station are as follows:

7 1. Bellacorick Bog Complex (cSAC) – this site consists of a dozen subsites, five of which fall either wholly or partially within 5km south and east of the station with one site as near as 300m. 2. Bellacorick Iron Flush (NHA and cSAC) – ca. 7km north-east of the station. 3. Carrowmore Lake Complex (cSAC) – nearest subsite of this complex is 4km northwest of the station. 4. Owenduff/Nephin Complex (pcSAC) – 10km southwest of the station.

Ground level concentrations of SO2 or NO2 are the main threat to sensitive flora or fauna. 3 The maximum modelled annual average concentration of NO2 of 5.7µg/m is well below the 3 AQS of 30 µg/m NOx to protect vegetation. The maximum modelled annual average 3 3 concentration of SO2 of 63 µg/m exceeds the AQS of 20 µg/m for protection of ecosystems however none of the sites above lie within the areas where exceedances of the standard are predicted. As discussed earlier it appears that the model over-predicts maximum SO2 concentrations. In addition the model is based on both units operating continuously over the year which does not occur.

FIRE-WATER RETENTION A risk assessment was undertaken to determine the requirement for a firewater retention facility on site. The report concluded that based on the low risk of an uncontrolled fire, the quantities of chemicals stored on-site and remediation and limitation measures available, a retention facility was not required.

RESIDUALS MANAGEMENT Because of the presence of an on-site landfill the full condition requiring a residuals management plan has been included in the PD.

SUBMISSIONS Two submissions on the application were received from: (i) Dúchas (ii) The North Western Regional Fisheries Board (NWRFB)

The submission from Dúchas states that they have no objection to this application as the station is due for decommissioning.

The submission from the NWRFB addresses a number of issues: (i) Orthophosphate concentrations in the discharge from the ash pond supernatant and the receiving waters are not discussed. This is an important parameter considering the receiving waters.

Concentrations of ortho-phosphate in the samples of ash leachate tested indicate levels of 0.21mg/l P. Based on the dilution available this would result in an increase in background concentrations of 4.6µg/l. Testing of the ash pond run-off at SW5 over the past three years by the EPA’s Regional Inspectorate, (on behalf of Mayo County Council) indicate a range of ortho-phosphate concentrations from <0.008 – 0.83mg/l. A requirement for quarterly monitoring of ortho-phosphate has been included in the PD at SW5. In addition ambient monitoring of the Owenmore and Oweninny rivers is required within 18 months of date of grant of the licence.

(ii) The issue of precipitation of ions as a result of neutralisation of the acid and base washes from resin regeneration has not been discussed.

Sulphuric acid and sodium hydroxide are the acid and bases used respectively for resin regeneration. The resultant salt is sodium sulphate which is soluble in water. Monitoring of

8 Total Dissolved Solids is required at SW1. An evaluation of results submitted as part of the application indicates no impact from the dissolved solids content at this location. River monitoring downstream of the station shows TDS concentrations of less than 230mg/l.

(iii) The issue of back wash water from the sand filter on site has not been addressed.

Filter wash water diverts to the main station settling pond prior to discharge at SW1.

(iv) The applicant refers to occasional testing of the condenser with tracer dye and the possibility of an acid cleaning of the boiler and states that the EPA will be informed. The Board also wishes to be informed prior to either procedure being carried out.

Condition 6.6 requires the Agency and the NWRFB to be notified prior to either procedure being carried out.

(v) Grease traps should be provided on the kitchen outlet to protect the Puraflo unit which drains the main buildings.

Condition 6.14 requires the licensee to install a grease trap on the canteen outlet.

(vi) Both percolation areas should be constructed with good quality, loamy soils with a ‘T’ value of 15-30.

Condition 6.3.10 requires an assessment of the sewage treatment facilities and percolation areas within 6 months of the date of grant of licence.

(vii) All chemicals must be carefully stored on site in bunded areas.

Condition 9.3.1 requires all tank and drum storage areas to be bunded from the date of grant of licence.

(viii) In relation to the use of ammonia for boiler treatment and pH balancing the NWRFB would like to see this issue discussed further in the context of toxicity to salmonid species.

An assessment of the impact of the ammonia discharged to the Oweninny River indicates an insignificant increase in background levels. Results of ammonia monitoring at up-stream and down stream locations over the past four years do not indicate an increase in ammonia concentrations arising from the activity.

Recommendations: It is recommended that a Proposed Determination be issued subject to the conditions and for the reasons as drafted.

Signed

______Mary Gurrie

Procedural Note

In the event that no objections are received to the Proposed Determination of the application, the final licence will issue from the division in accordance with Section 85(4) of the Environmental Protection Agency Act 1992 as soon as may be.

9