Donegal County Council August 2008 Moville and Greencastle Sewerage Scheme Environmental Impact Statement Section 8. For inspection purposes only.

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1 Environmental Impact Statement Section 8 PLATES EPA Export :10:54:05

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4 Environmental Impact Statement Section 9 - Page 1 SECTION 9 TRAFFIC ASSESSMENT The Traffic and Transportation Section of this EIS is provided in two sections: WWTP at Carnagarve and outfall pipeline; Pumping Stations and emergency overflows. 9.1 Waste Water Treatment Plant and Outfall pipeline Introduction The Traffic and Transportation Section of this EIS provides an assessment of the potential traffic impacts on the local road network for road users to and from the proposed Moville / Greencastle Sewerage Scheme. The study aims to assess the following: Existing road conditions; Proposed access arrangements for the scheme; Traffic volumes generated by the scheme; The effect on the local road network and road users of generated traffic by the construction and operation of the proposed development; The potential environmental impacts associated with traffic generated by the scheme; Mitigation measures for the environmental impacts associated with traffic generated by the scheme. The study is based on the findings of site visits, traffic observations, on-site traffic counts, and consultation with the various stakeholders Methodology The following steps were undertaken as part of the compilation of the transportation assessment for the EIS: In preparing this Chapter, reference has been made to the following documents: i. Traffic Management Guidelines (DoELG, 2003); ii. iii. Guidelines for Traffic Impact Assessment (TIA), Institution of Highways & Transportation (IHT, 1994); NRA RT201-Expansion Factors for Short Period Traffic Counts; EPA Export :10:54:06

5 Environmental Impact Statement Section 9 - Page 2 iv. NRA Future Traffic Forecasts ; v. NRA Road Geometry Handbook; vi. J.B. Barry & Partners Site layout drawing -PR-400 and various location plans. Consultation was made with the Roads Department of Donegal County Council in order to establish key network information which was employed in the design of the traffic survey and analysis; Traffic survey locations were chosen so as to best reflect the impacts of likely traffic generation to and from the subject development; An empirical approach to trip generation was employed and industry standard computer aided modelling techniques were used for traffic analysis; Reference was made to other relevant studies undertaken elsewhere in Ireland for projects of a similar nature Existing Environment Site Location The WWTP site for the proposed Moville / Greencastle Sewerage Scheme is located on the Inishowen Peninsula in Co. Donegal, roughly midway between the towns of Moville and Greencastle in the town land of Carnagarve. The green field site lies amongst undulating farmland approximately half a kilometre inland from the shores of Lough Foyle, the nearest major watercourse. A number of residential properties and farmhouses lie in close proximity to the south, fronting the adjacent Regional Road 1 R241, and in addition to the south west on the adjacent local Secondary Road LS6431. The non traffic related environmental impacts to these properties are dealt with elsewhere within this EIS. Moville Parish GAA Ground lies in close proximity to the south-west of the site. The GAA ground attracts most of its trips during weekday evenings and weekend days and will therefore not generally conflict with the operation of the plant whose operational trips fall within normal business hours. Within the GAA ground there is a prefabricated unit containing a local Primary School. The school has two classes and two permanent teachers serving approximately 45 pupils. Travel for the school children to and from the site is managed efficiently with two mini-buses and one large bus ferrying the pupils between the school and their homes daily between Monday and Friday in term time. 1 Road layouts have been illustrated in Figures to EPA Export :10:54:06

6 Environmental Impact Statement Section 9 - Page Surrounding Road Network The WWTP site lies immediately adjacent and to the east of the local secondary road LS6461. The LS6461 is a bi-directional single carriageway road whose pavement width in the vicinity of the subject site varies between 3.0 metres and 4.5 metres. The LS6461 runs in a northerly direction from its intersection with the Regional Road R241 south of the site, to a termination point several kilometres further in the hills overlooking Lough Foyle. Another local secondary road, the LS6431, runs in a westerly direction from the site from a T-intersection with the LS6461 immediately to the south west of the site, and serves as an access to the local GAA field, Primary School and local residences. The LS6431 is a bi-directional single carriageway road with a pavement width in the order of 6m at its intersection with the LS6461. Site observations indicate that from a network perspective, vehicle movements through the junction are relatively low, and capacity is unlikely to be an issue now, or in the design year for the proposed WWTP. Figure 9.1 Site Location Plan. LS6441 LS6431 LS6461 Site Location R241 LS1451 A regional link to the site is provided by the R241 which lies to the south of the subject site by approximately 430 metres. The R241 is a regional road which links the towns of Moville and Greencastle and continues onwards towards Inishowen Head before terminating close to Dunagree Point, which lies on the north-east extremity of the Inishowen peninsula. The R241 is a bi-directional single carriageway road providing lane widths in the order of 4 metres. In the vicinity of the site hard verges are provided adjacent to the northbound carriageway at approximately 1.2 metres wide, and adjacent to the southbound carriageway the verge is in the order of 3.0 metres wide. The nearest major road junction to the subject site is the intersection of the local secondary road LS6461 and the regional road R241 which lies to the south of the EPA Export :10:54:06

7 Environmental Impact Statement Section 9 - Page 4 subject site. The junction is situated on the R241 at the apex of a curve in the road whose radius is in excess of 500 metres. A local access road slices through the inside of the curvature forming a chord along the inside of the bend, a grassed island in the shape of a segment is then formed between the local access road (the chord) and the curvature of the adjacent R241. The LS6461 meets the local access forming a T-junction. Refer to Figures to at the end of this section for a schematic representation of the junction. In essence, the intersection of the LS6461 and R241 described above operates as a major/minor priority T-Junction, and for the purposes of traffic modelling and analysis the junction will be evaluated on this basis Traffic Surveys and Analysis To determine the current traffic behaviour in the vicinity of the site, a number of turning movement surveys were carried out at the junction of the LS6461 and R241, described in section , considered the closest major junction which is likely to be directly affected by traffic movements borne of the proposed WWTP. A full 12 hour classified traffic count was commissioned between 7am and 7pm on Tuesday 17th April 2007 for the junction of the LS6461 and LS6431 in order to determine the percentage of vehicles passing through the junction which pass the wastewater treatment plant site on the LS6461. The traffic count revealed the following 12 hour flows: LS hour bi-directional flow = 31 vehicles (averaging 1 vehicle every 23 minutes) LS hour bi-directional flow = 270 vehicles (averaging 1 vehicle every 2 minutes 40 seconds) Further analysis of the 12 hour classified traffic count of the intersection of the LS6431 and the LS6461 revealed: 90% of traffic passing through the junction utilises the LS % of traffic passing through the junction utilises the LS6461 During the critical PM peak, 3 vehicles travelled along the LS6461 A traffic count survey was also carried out at the junction of the LS6461 and R241 in the morning peak between 08:00 hours and 09:30 hours and the evening peak between 16:30 hours and 18:00 hours on Tuesday 12th April An initial analysis of the traffic data was undertaken in order to establish the peak 60 minutes for each of the 90 minute AM and PM traffic surveys recorded. This initial analysis has concluded that: The peak hour for the AM period occurred between 08:30 09:30 hours; The peak hour for the PM period occurred between 17:00 18:00 hours; Refer to Figures and for results of the Traffic Count Survey for the junction, shown for the morning and evening peaks in Figures and Figure EPA Export :10:54:06

8 Environmental Impact Statement Section 9 - Page respectively. See also Appendix F for results of the base year 2005 traffic count at the junction. The results of the morning peak hour survey reveal the following: A two way flow of 284 vehicles per hour pass along the R241, with flows split 46% northbound and 54% southbound; A two way flow of 57 vehicles per hour pass along the LS6461; with flows again split 46% northbound and 54% southbound; Bi-directional flow values are well balanced indicating no evidence of tidal traffic flow movements. The results of the evening peak hour survey reveal the following: A two way flow of 384 vehicles per hour pass along the R241, with flows split 52% northbound and 48% southbound; A two way flow of 59 vehicles per hour pass along the LS6461; with flows split 51% northbound and 49% southbound; Site observations revealed the majority of the traffic was attracted towards the LS6431 due to the presence of the school, GAA grounds and houses; Again bi-directional flow values are well balanced indicating no evidence of tidal traffic flow movements The traffic flow survey has revealed that the evening peak hour is more intense than the AM peak hour, with traffic flows on the R241 being some 15% greater than the AM peak. The PM peak period may therefore be considered the critical peak. In representing the worst case scenario for driver delay, the modelling exercise for traffic movements to and from the subject site will be based on traffic flows recorded for the evening peak hour. Reference to RT201 Expansion Factors for Short Period Traffic Counts, published by the NRA, specifies an evening peak hour expansion factor of (plus or minus 24% at the 68% confidence level) 2 to obtain an Annual Average Daily Traffic (AADT) flow. Based on this, the AADT flows for each Road in turn are as follows: R241: 5,830 AADT LS6461: 776 AADT In order to establish the existing traffic capacity of the surrounding roads, reference is made to TA 79/99 Traffic Capacity of Urban Roads (Vol. 5, Sect. 1, Part 3 of the Design Manual for Roads and Bridges). Therein, existing one way traffic capacity for each road in turn has been defined as follows: R241: 1,470 vehicles per hour 2 Reference is made to Table 3 b Rural Intertown Routes. EPA Export :10:54:07

9 Environmental Impact Statement Section 9 - Page 6 3 LS6461: 663 vehicles per hour (VPH) In comparing the existing flows with the theoretical capacities as referenced in Table 9.1 following, the existing two-way flows on both roads are well within their respective theoretical capacities. It can be surmised therefore that the existing road network is well within its potential capacity to carry traffic movements. Table R241 & LS6461 PM Peak Existing Flow Compared to Capacity: Road AADT Existing Two Way Flow VPH 4 Existing Two Way Capacity VPH LS R241 5, In order to quantify the operation of the existing priority controlled junction at the junction of the LS6461 and R241 (noting the assumption referred to previously in section that this junction is for the purposes of traffic analysis a major/minor priority T-Junction), a capacity assessment was undertaken using the UK Department of Transport program PICADY (Priority Intersection Capacity and Delay) and the surveyed results outlined above. A summary of the results of the analysis for the existing evening peak hour is shown in Table 9.2 following. Table PICADY Capacity Analysis Results for the Existing Evening Peak Hour Junction of LS6461 & R241 Approach Max. Degree of Saturation ( 5 RFC) Average Queue (Vehicles) Average Delay (Seconds) R241 Moville LS R241 Greencastle See Appendix F Volume 2 for PICADY traffic modelling output files 3 Capacity considered on the section of the LS6461 between the intersection with the R241 and the LS6431 only. 4 From TA 79/99 Traffic Capacity of Urban Roads one way traffic capacity in vph x 2 (converted to two way flow e.g. 663 x 2 = 1326 VPH). The existing theoretical capacity is substantially greater than existing flows for both the AM & PM peaks. 5 RFC: Ratio of Flow to Capacity, another term for degree of saturation. Both refer to residual capacity of the junction arm referred to. EPA Export :10:54:07

10 Environmental Impact Statement Section 9 - Page 7 The normal design threshold for the Ratio of Flow to Capacity (abbreviated to RFC) in PICADY is 0.85 (for Level of Service D) 6. The results shown in Table 9.2 therefore demonstrate that the intersection is currently operating well within its capacity during the evening peak hour, with no significant queuing or delay to motorists. The results of this analysis concur with observations recorded during site visits Road Infrastructure Improvements (Drawing Figures ) A number of local road network improvements should be made in order to facilitate the safe operation of traffic generated by the WWTP site. These proposed road network improvements will have the added benefit of improving road safety for existing users in the local and wider community. See Figures to at the end of this section. These measures include the following: New T-Junction Arrangement of R241 and Local Access Road (Figures ) In order to remove the road safety risks associated with the current configuration of the local access road providing access to the LS6461 from the R241, a new priority controlled T-junction arrangement of the local access road and R241 is proposed. This will have the benefit of closing off the two existing Y-junctions at the interface of the R241 and local access road which provide sub standard visibility for road users entering and exiting the local access road from the R241. The new T-junction arrangement of the local access road and R241 is proposed at a location approximately 76 metres south of the existing T-junction of the local access road and LS6461, at the apex of a curve in the R241 and grassed island separating the R241 from the local access road. This location provides visibility for vehicles exiting from the local access road onto the R241 which meets visibility criteria set out in NRA TD 42/95 i.e. an envelope of visibility of 160 metres from the minor road onto the major road with a design speed of 85kph on the major road. Full forward visibility is also provided on the R241 with a stopping sight distance in advance of the new T-junction arrangement in excess of 160 metres which meets desirable minimum stopping sight criteria as set out in NRA TD 9/00. See Figures 9.2 and 9.3 following which show visibility in the northbound and southbound direction on the R241 at the proposed location of the new T-junction 6 A junction providing a Level of Service lower than Level D is considered not to meet acceptable design standards, as the junction may be congested. Where possible, drivers will naturally find alternative routes in these cases. EPA Export :10:54:07

11 Environmental Impact Statement Section 9 - Page 8 Figure 9.2 Visibility in direction of Moville on R241 from new T-junction location 160 metres Figure 9.3 Visibility in direction of Greencastle on R241 from new T-junction location 160 metres EPA Export :10:54:07

12 Environmental Impact Statement Section 9 - Page 9 The new T-junction arrangement will include two 4 metre wide lanes on the R241 for straight ahead traffic and a 3 metre wide right turning lane on the approach to the junction from Greencastle. The right turning lane will remove the risk of right turning traffic on the R241 coming from the direction of Greencastle impeding the forward movement of traffic on the R241 heading towards Moville. The new junction arrangement will require some local widening of the R241 in the vicinity of the grassed island. Currently there are hard verges on both sides of the R241 in the vicinity of the grassed island formed by loose stone. It is recommended that the hard verge on the grassed island side of the R241 be paved in order to provide the required lane width and paved approach to the new T-Junction. Some local widening on the other side of the R241 will also be required in order to provide desired lane width. The new T-junction location will be located at a point which does not conflict with an existing entrance to a residential dwelling on the local access road. The junction location will not require the relocation of existing overhead Eircom poles which are placed at irregular intervals along the grassed island. However, the junction location may require the removal of one or two young trees planted on the island Improve Junction Discipline at Existing T-Junction of LS6461 and Local Access Road (Figure 9.1.7) Improve driver discipline and road safety at the junction of the LS6461 and local access road through the provision of advance warning signage, junction signage and improved road markings. The existing junction does not have any junction signage and required road markings Improve Visibility at Existing T-junction of LS6461 and LS6431 (Figures ) The existing T-junction configuration of the LS6461 and LS6431 provides substandard visibility in the direction of the proposed WWTP for vehicles exiting the LS6431 onto the LS6461. An existing fence and high hedgerow of the corner house at the junction blocks visibility to the left for vehicles wishing to exit onto the LS6461 from the LS6431. See Figure 9.4 following for photograph showing sub standard visibility at the junction. In order to improve visibility at the junction it is proposed to bring forward the junction of the LS6461 and LS6431 by approximately 7 metres through the realignment and widening of the LS6461 between the WWTP site entrance and the existing T-junction of the LS6461 and local access road. This proposal will require a land take from the agricultural land directly opposite the existing T-junction of LS6461 and LS6431 in order to provide improved visibility at the junction. The new proposed junction configuration will provide visibility at the junction in accordance with visibility criteria set out in NRA TD 42/95, subject to existing level differences on the LS6461 north of the junction being designed out to provide adequate visibility. The existing T-junction of the LS6461 and LS6431 lies approximately 5.5 metres below a point 80 metres to the north of the junction on the LS6461. EPA Export :10:54:07

13 Environmental Impact Statement Section 9 - Page 10 Figure 9.4 Visibility at Existing T-junction of LS6461/LS6431 Junction of LS6461/LS Realignment and Widening of the LS6461 between the Proposed WWTP Site Entrance and Existing T-junction of LS6461 and Local Access Road (Figure 9.1.8) LS6461 The existing geometry of the LS6461 has a road pavement width of less than 3 metres in the vicinity of the WWTP site entrance and existing T-junction of the LS6461 and LS6431. Between the existing T-junctions of the LS6461/LS6431 and LS6461/local access road the road pavement widens to approximately 4.5 metres. Existing road pavement widths on the section of LS6461 described above would not allow a large sized vehicle generated by the WWTP (skip lorry) and car pass safely side by side, particularly on the section between the WWTP site entrance and existing T-junction of LS6461 and LS6431. See Figure 9.5 following. In addition, the longitudinal alignment of the LS6461 curves sharply on the crest of a hill to the north of the existing T-junction of the LS6461 and LS6431 with a sharp fall in level providing sub standard forward visibility. EPA Export :10:54:07

14 Environmental Impact Statement Section 9 - Page 11 Figure 9.5 Existing Road Width on LS6461 between WWTP & Junction of LS6461/LS metres In order to improve the alignment and pavement width of the LS6461 between the WWTP site entrance and the existing T-junction of the LS6461 and local access road, it is proposed to widen this section of the LS6461 to 6 metres and realign the section of LS6461 at the existing T-junction of LS6461/LS6431 to form a straight longitudinal alignment between the WWTP site entrance and T- junction of LS6461 and local access road. This proposal is detailed in Figure The proposed widening and realignment of the LS6461 between the WWTP site entrance and T-junction of LS6461 and local access road will require the following works: Widen the section of LS6461 between the WWTP site entrance and a point 220 metres to the south (where the existing alignment curves down to the junction of LS6461/LS6431) by approximately 3 metres into the existing road side boundary on the eastern side of the LS6461; Pipe existing drainage ditch on eastern side of LS6461 under new road pavement; Realign the section of LS6461 between the existing curved point on the road described above and the existing T-junction of LS6461/local access road by taking land from agricultural land to the south of the WWTP site and providing a straight longitudinal alignment; Provide necessary drainage facilities for realignment; EPA Export :10:54:07

15 Environmental Impact Statement Section 9 - Page 12 Design LS6461 at an appropriate gradient between new T-junction of LS6461 and LS6431 and a point 80 metres to the north for improved vertical alignment; Bring forward existing T-junction of LS6461 and LS6431 to improve visibility at this junction as previously described (Figure 9.1.9); The above works will require a land take from the existing agricultural land to the south of the proposed WWTP on the eastern side of the LS6461 with a 2.5 metre wide reservation to a new road boundary fence line. Land take varying from 2.5 metres to 12 metres. Provide new road marking and signage at the new T-junction of LS6461 and LS6431; The new proposed realigned section of LS6461 between the WWTP site entrance and existing T-junction of LS6461 and local access road to the south of the WWTP site will have a road pavement width of approximately 6 metres. The improved road will provide ample width for vehicles to safely pass and will also provide improved forward visibility. See also Figures for Autotrack software analysis of the turning movements for a small articulated vehicle 7 and bus 8 at the junctions of R241/Local Access Road, LS6461/Local Access Road, and LS6461/LS6431 which show that the proposed and existing junction geometries can comfortably accommodate the expected turning movements for vehicles generated by the operation of the WWTP Traffic on Site Traffic on site will be controlled primarily by the design and layout of the site, along with signage, road markings, barriers and verbal instructions from staff. Car parking for staff will be provided internally within the curtilage of the site, and suitable entrance and turning circles will be provided to facilitate turning movements for HGV s (heavy goods vehicles) Impacts on the environment Construction Phase The construction stage of the proposed Waste Water Treatment Plant is expected to be in the order of 18 months. During the construction stage it is expected that between people will be employed on the site. Normal working hours will be between 8.00am and 6.00pm, five days per week with possible working on Saturday mornings. Assuming each of the construction workers arrives to work by car, and assuming 20 people are employed on the site, a maximum of 20 cars will arrive at the site between 7.00am and 8.00am, and the same number will leave between 5.00pm and 6.00pm. 7 Similar to the maximum anticipated size of vehicle expected to service the site for outbound waste 8 Similar to buses currently serving local primary school and GAA field EPA Export :10:54:07

16 Environmental Impact Statement Section 9 - Page 13 During construction, trucks and vans will be delivering materials to the site daily. It is estimated that this could peak at trucks per day coming to site depending on the construction activity. The arrivals of trucks and vans to the site are expected to be evenly spread throughout the day. In summary, it is expected that during the construction period, a maximum of up to 15 trucks per day could be arriving at, and leaving the site and up to 20 cars could arrive in the morning and leave in the evening. Temporary Diversions to Facilitate Construction During the construction phase there will be a requirement for temporary road closures of the local access road forming the junction of the LS6461 and R241, described in section , and the LS6461 between the WWTP site entrance and R241 in order to facilitate pipe laying, road widening and the construction of the WWTP entrance. In order to address road safety during road closures to facilitate pipe laying, the contractor in charge of the works will provide traffic management measures in line with Chapter 8 of the Department of Environment Traffic Signs Manual. Dependent on the sequencing of works, the contractors traffic management measures may include controlling the entry and exit of construction vehicles with a banks-man and / or a barrier control system. Referencing Figure 9.1 site location plan, a number of temporary diversions are available to traffic wishing to access the local access road and LS6461 utilising a combination of the LS1451 (Moville), LS6431, LS6441, and R241 depending on trip destination. Diversions will be clearly sign posted by the contractor awarded the construction of the scheme following consultation with the Local Authority and An Garda Síochána Operational Phase The potential environmental impacts generated by traffic associated with the proposed WWTP are in relation to the existing road system and inhabitants within the surrounding area. This will apply at both the construction and operational stages. This increased volume of traffic will have potential impacts on humans such as: Increased noise and vibration levels Visual Impact Community Severance Pedestrian Stress, Delay and Amenity Cyclist Delay Driver Delay Increased Accident Potential Increased Air Pollution Increased Dust & Litter Generation EPA Export :10:54:07

17 Environmental Impact Statement Section 9 - Page 14 The above impacts, although not necessarily significant, require consideration to determine their extent. Certain groups of people whose immune systems are suppressed, that is the very young and the elderly or those in sensitive locations (i.e. hospitals, schools, etc) may be affected more than others. Others who may be affected are those at home, work, walking or cycling The impact on the above groups will depend on various factors such as: Volume of traffic Speeds and operational characteristics Composition of traffic (e.g. the heavy vehicle content) The perception of traffic change on humans will depend on factors such as: Existing traffic Traffic route Time of day Variation of traffic volume Design and layout of roads in the vicinity Land use activities adjacent to the route A review of each of the previously noted potential impacts on humans from the traffic component of the scheme is expanded upon in Volume 2 Appendix Traffic Appendices. This information is pertinent to both the construction and operational phases of the development Expected Traffic Generation and Distribution Construction Phase As discussed previously in Section it is expected that during the construction period, a maximum of up to 15 trucks per day could be arriving and leaving the site and up to 20 cars could arrive in the morning and leave in the evening. Operational Phase In order to assess the impact of traffic generated by the proposed development on the surrounding network, it is first necessary to predict the likely maximum traffic volumes that will be generated during the evening peak hour. As noted in Section , the evening peak hour has been identified as the critical peak. Traffic generation for the scheme has been calculated for the evening (PM) peak. This combination represents the worst case scenario, and therefore provides a robust engineering assessment of the schemes potential traffic impact. (This is very conservative as it assumes the worst case scenario in all assumptions). To determine the likely traffic generation associated with the proposed development, a survey was undertaken of trip generation information for similar sewerage treatment plants within Ireland to produce a representative EPA Export :10:54:07

18 Environmental Impact Statement Section 9 - Page 15 expectation of traffic flow generated by the proposed facility for the evening peak hour. By using recent live trip generation data for similar facilities within the Donegal area, the likelihood of predicting an accurate trip generation profile is greatly increased. Based on the desk study of similar sites and discussions with employees of Donegal County Council, the maximum (worse case scenario) expected traffic generation to the proposed WWTP may be summarised as noted on the following page. Table 9.3 Maximum Estimated Trip Generation, Evening Peak Hour TRIP TYPE & ASSUMPTIONS BEHIND THE ESTIMATION Employee trips. Approximately 10 people will be employed at the plant. Assume worst case that all drive separate cars (the 2 arrivals are based on the possibility that 2 employees returned from errands within the PM peak) Maintenance vehicle trips. Assume worst case scenario that a maintenance fitter is called out every day, and the visit coincides with the PM peak. Delivery & visitor trips. Assume worst case that there is a delivery and a visitor trip each weekday, assume that these trips coincide with the PM peak. Trips for removal of screenings and grit. Noted as one HGV trip per month. Assume worst case scenario that this journey coincides with the PM peak hour considered. Collection of treated sludge. Noted as one 9 cubic metre skip exchanged every 4 days. Assume worst case scenario that the exchange coincides with the PM peak considered. Delivery of sludge from other plants. These trips are unlikely to materialize; however for the purposes of worst case scenario modelling assume 2 HGV trips in the PM peak hour. Evening Peak Hour Arrivals Departures Total Trips in PM Peak Hour: 9 17 EPA Export :10:54:08

19 Environmental Impact Statement Section 9 - Page 16 Based on the surrounding road network and site observations, it is expected that traffic generated to the site will be split evenly between the R241 northbound and the R241 southbound. Figure shows the expected future traffic flows at the new T-junction of the R241 and local access road providing access to the site in the 2015 Design Year. Turning movements at the junction have been based on the Base Year Surveyed Traffic Flows for the 2005 Evening Peak shown in Figure The Projected 2015 Evening Peak Flows shown in Figure assumes a network traffic growth rate of 3% per annum over a 10 year design horizon to the Design Year (2015), in addition to the expected traffic flows generated by the proposed development. In order to determine the future operation of the surrounding road network, a modelling exercise was carried out on the junction of the R241 and local access road using the PICADY software based on the Projected 2015 Design Year Traffic Flows shown in Figure A summary of the results of the analysis for the Future Design Year evening peak hour are shown in Table 9.4 following. Table PICADY Capacity Analysis Results for the 2015 Design Year Evening Peak Hour Junction of LS6461 & R241 Approach Max. Degree of Saturation (RFC) Average Queue (Vehicles) Average Delay (Seconds) R241 Moville Local Access Road R241 Greencastle See Appendix G for PICADY traffic modelling output files The normal design threshold for the Ratio of Flow to Capacity (abbreviated to RFC) in PICADY is 0.85 (for Level of Service D) 9. The results shown in Table 9.4 therefore demonstrate that the new intersection will operate well within capacity during the evening peak hour in the 2015 Design Year. The expected queuing and delays to motorists are all within acceptable limits. 9 A junction providing a Level of Service lower than Level D is considered not to meet acceptable design standards, as the junction may be congested. Where possible, drivers will naturally find alternative routes in these cases. EPA Export :10:54:08

20 Environmental Impact Statement Section 9 - Page Mitigation Measures Construction Phase In order to mitigate against potential impacts of the scheme due to traffic generated by the construction phase, a construction traffic management plan will be developed by the contractor(s) prior to the commencement of work on site, in consultation with Donegal County Council and An Garda Siochána for agreement of relevant construction traffic management and monitoring measures. The Traffic Management Plan will take cognisance of all road users particularly those who are vulnerable or impaired. The following general measures will apply: The construction traffic management plan will identify suitable (signed) haulage and delivery routes for HGVs, appropriate locations for marshalling of delivery vehicles, and outline requirements for banksmen; Appropriate warning signage for the site accesses will be provided in order to alert both delivery staff and the general public of the access; Details of working hours will be included in the plan. Deliveries of materials or the exportation of spoil from the site will avoid both AM and PM peak hours; Construction debris (particularly site clearance, spoil removal and dirty water runoff such as dewatering or wash from concreting activities) can have a significant impact on footpaths, watercourses and roads adjoining a construction site, if not adequately dealt with. There will, therefore, be a requirement for comprehensive measures as part of the plan to mitigate against the above; Banksmen will control access and egress from each site access and or site compound; Wheel washers / judder bars will be provided at each site access to clean vehicles exiting the sites during any spoil removal; All loads to / from the site will be properly stowed and secured with a tarpaulin, where appropriate; Routine sweeping / cleaning and maintenance of the road adjacent to the site will also be carried out; Road or lane Closures (if any) will be advertised in the media and through signage on the route affected by the closure in advance of the closure; Diversions (if any) will be delineated using appropriate signage and removed when the works have been completed; EPA Export :10:54:08

21 Environmental Impact Statement Section 9 - Page Operational Phase In order to minimise the traffic impact resulting from the proposed sewerage treatment plant during the operational phase, the following measures will be adopted: Ensure vehicles associated with the delivery and removal of sludge are appropriately sealed and covered; Ensure the site is always appropriately manned; Ensue access arrangements for the site are properly designed i.e. vehicles can turn safely into the site, adequate parking is provided within the site and adequate turning circles for vehicles within the site are provided. Install adequate signage and notice boards for the site; Providing adequate lighting for the site. Road Network Improvements A number of local road network improvements should be made in order to facilitate the safe operation of traffic generated by the WWTP site. These proposed road network improvements will have the added benefit of improving road safety for existing users in the local and wider community. See Section herein and Figures to at the end of this section Residual Impacts The implementation of the proposed mitigation measures will ensure that there is no significant residual environmental impact as a result of the traffic component of the proposed development. During the construction stage, damage to surrounding roads by heavy vehicles can be problematic. Again, monitoring during the construction phase will be vital, to ensure that any unnecessary damage is identified at an early stage, and appropriate mitigation measures taken to counteract it. In summary traffic movement associated with the proposed development will have minimal impact on the surrounding traffic environment. The overall residual impact of the scheme on the road network is likely to be minimal Monitoring No additional post-development monitoring will be necessary with this development. As part of its governing role over the surrounding highway infrastructure, Donegal County Council will be monitoring the performance of the junctions detailed within this report as part of its cyclic maintenance regime for the area. EPA Export :10:54:08

22 Environmental Impact Statement Section 9 - Page Conclusion There will be no significant adverse environmental impacts resulting from traffic generated by the development. 9.2 Pumping Stations and Emergency Outfalls Introduction The Traffic and Transportation Section of this EIS provides an assessment of the potential traffic impacts on the local road network for road users generated by the construction and operation of 4 no. proposed pumping stations and their emergency outfalls designed to serve the Moville and Greencastle Sewerage Scheme. The study aims to assess the following: Existing road conditions; Proposed access arrangements for the pumping stations; Traffic volumes generated by each pumping station; The effect on the local road network and road users of traffic generated by the operation of the proposed pumping stations; The potential environmental impacts associated with traffic generated by the proposed pumping stations; Mitigation measures for the environmental impacts associated with traffic generated by the proposed pumping stations. The study is based on the findings of site visits, traffic observations, and consultation with Donegal County Council Methodology The methodology is described in Section Existing Environment Site Locations The 4 No. pumping stations are as detailed in Figure 9.2 Carrickarory Pumping Station R238 at Carrickarory, 1km south west of Moville; River Row Pumping Station River Row, Moville; Glenburnie Pumping Station Lough Foyle, 2 km north east of Moville; Greencastle Pumping Station Greencastle Harbour area. EPA Export :10:54:08

23 Environmental Impact Statement Section 9 - Page 20 Figure 9.2 Pumping Station Site Location Plan WWTP Site Greencastle PS River Row PS Glenburnie PS Carrickarory PS The proposed position of the Carrickarory pumping station is located in a Greenfield site off the Regional Road R238, approximately 1 kilometre south west of the town of Moville. The site is bordered by the R238 to the south, with a seawall bordering the R238 further to the south. To the north, the site is bordered by dense deciduous tree growth. An unused boatyard lies immediately adjacent to the site to the east and there is a residential dwelling approximately 100m to the south west. Carrickarory pier is located on the opposite side of the R238 approximately 150 metres to the south west of the site. The emergency outfall from the pumping station will cross the R238 and discharge into the Lough below water level. See Figure following for photograph depicting Carrickarory pumping station site location. Figure Carrickarory Pumping Station Site Location Proposed Site R238 Road EPA Export :10:54:08

24 Environmental Impact Statement Section 9 - Page 21 The proposed pumping station site at River Row is located in an open green area on the banks of the River Bredagh, adjacent to the end of a cul-de-sac (River Row) used to access a row of terraced houses in the town of Moville. The site is bordered to the north and west by the River Bredagh which runs into Lough Foyle behind the last residential dwelling on the cul-de-sac. River Row and the open green area border the site to the south and east respectively. Figure River Row Pumping Station Site Location Proposed Site River Row The emergency outfall from the pumping station shall follow the banks of the Bredagh River, past Moville harbour and then discharge into the lough below water level at Moville pier. A second emergency outfall will discharge into the Bredagh River/estuary adjacent to the site and will therefore not affect any existing road traffic routes. EPA Export :10:54:09

25 Environmental Impact Statement Section 9 - Page 22 The proposed pumping station site at Glenburnie is located midway between the towns of Moville and Greencastle, approximately 2 kilometres north east of Moville and 2 kilometres south west of Greencastle. The site is located adjacent to an existing car park at Lough Foyle, which is located at the end of a short cul-de-sac running south from it s junction with the Regional Road R241 midway between Moville and Greencastle. The cul-de-sac forms an access to a small beach as well as local residential dwellings located directly off the cul-de-sac. A beach front and coastal footpath lie to the south of the site, whilst dense hedgerow and tree growth borders the site to the north. There is a small car-parking area just to the north east of the site (pictured). The emergency outfall from the pumping station shall travel along the coastal footpath and discharge into a small stream which flows into the Lough Foyle. Figure Glenburnie Pumping Station Site Location Proposed Site EPA Export :10:54:09

26 Environmental Impact Statement Section 9 - Page 23 The proposed site for Greencastle pumping station is located in the town of Greencastle, just off the main street in a town centre car park. See figure following for a photograph of the proposed site location for the Greencastle Pumping Station. The car park is bordered on its northern perimeter by the Regional Road R241 which forms the main street of Greencastle. On its southern perimeter the car park is bordered by a seawall and rock barrier and to the west by Greencastle Harbour. A town centre green amenity area borders the pumping site to the east. The car park is occupied by circa 34 car park spaces and by an existing public toilet facility. It is proposed to locate the pumping station behind the public toilets and occupy an area of the car park. The emergency outfall from the pumping station does not cross any public roads. It shall discharge into the lough below water level. Figure Greencastle Pumping Station Site Location Proposed Site R241 EPA Export :10:54:09

27 Environmental Impact Statement Section 9 - Page Surrounding Road Network Carrickarory Pumping Station The proposed site lies immediately adjacent and to the north of the R238 Regional Road. The R238 is a bi-directional single carriageway road whose pavement width in the vicinity of the pumping station site is in the order of 6 metres. The R238 heads inland at Moville and runs in a south westerly direction from Moville towards Derry City. The longitudinal geometry of the R238 in the vicinity of the site is reasonably straight, with the road curving gently away from the site towards the town of Moville. The vertical geometry of the road is flat at the proposed site entrance. In the vicinity of the site, the R238 is bound by a 1.2 metre high wall covered in ivy on its northern side and by a 0.5 metre high seawall on its southern side. There are no road markings at the time of writing on the R238 as it has recently been resurfaced with tar and chip road surfacing. The posted speed limit in the vicinity of the site is 60 kph (kilometres per hour). River Row Pumping Station The proposed site for River Row pumping station is located at the end of a narrow-cul-de-sac running parallel to the River Bredagh in the town of Moville. River Row (cul-de-sac) has a pavement width of 4 metres and a 1.1 metre wide footpath on its southern side serving a row of terraced houses. The longitudinal and vertical geometry of River Row may be considered as flat and without curvature. The existing road pavement is in poor condition with cracking and rutting along its length. At the proposed site entrance for the pumping station, River Row terminates in advance of a residential dwelling. The road surface changes from a flexible pavement at this point to an unbound gravel surface. There is a small turning area adjacent to the proposed site entrance. River Row is bordered on its northern perimeter by a grassed area which forms the southern bank of the River Bredagh. There is public lighting located intermittently along the northern and southern sides of River Row. River Row is accessed via the major/minor priority controlled T-Junction of Moville Pier access road and River Row. Glenburnie Pumping Station The proposed site for Glenburnie pumping station lies at the end of a short culde-sac accessing Lough Foyle off the Regional Road R241. The cul-de-sac forms the minor arm of a priority controlled T- Junction with the R241 and terminates in a small car park which measures approximately 9 metres by 16 metres. The cul-de-sac has a pavement width of the order of 3 metres which widens out to 6 metres at its junction with the R241. There are a number of private entrances off both sides of the cul-de-sac and the passing of opposing vehicle EPA Export :10:54:09

28 Environmental Impact Statement Section 9 - Page 25 movements is aided by vehicles pulling into these private entrances, and this effectively serves to keep vehicle speeds down. There are two private residences on both sides of the cul-de-sac at the T- Junction, with one of the residences accessed directly via the T-Junction and the other off the local access road. Figure Glenburnie Pumping Station T-Junction of R241 and Cul-de-sac R241 Road The cul-de-sac winds down to Lough Foyle from the T-Junction with the R241, sloping at a gradient away from the R241. The road is bound on both sides by high hedgerow and trees and the road surface is poor with widespread cracking and rutting. The R241 has a straight longitudinal profile and is relatively flat in the vicinity of its junction with the cul-de-sac. The R241 is bi-directional, and has a pavement width of 8 metres with an unbound granular hard shoulder in the order of 2 metres width on its southern edge. At the time of writing there were no road markings on the R241 in the vicinity of the site, as the road has recently been re-surfaced. There is no public lighting in the vicinity of the T-Junction. Visibility is good turning left and right from the R241 into the cul-de-sac. However, visibility is poor to the right exiting the cul-de-sac onto the R241, with sightlines being obstructed by the presence of a high hedge along the boundary wall of the residential dwelling accessed via the T-Junction. Visibility to the left is also sub-standard with the presence of a residential boundary wall hindering views on egress. There are stop markings placed on the cul-de-sac at its junction with the R241. There is no stop sign to accompany the road markings. Greencastle Pumping Station Cul de Sac / Local Access Road The proposed site for Greencastle pumping station is located in a town car park off the main street of Greencastle, which is part of the Regional Road R241. The EPA Export :10:54:09

29 Environmental Impact Statement Section 9 - Page 26 car park is located on the apex of a curve in the R241 as the road enters the town of Greencastle. The vertical geometry of the road is relatively flat in the vicinity of the car park. Access to the car park may be gained directly off the R241 on the outside of an apex in a curve in the road. A 2.5 metre wide walled island splits the frontage of the car park onto the R241 into two, with an eastern access directly off the R241 and a western access via a priority controlled T-Junction formed by the intersection of an access road to Greencastle port and the R241. Visibility accessing and exiting the car park is acceptable, as the location of the car park entrances on the outside apex of a curve in the R241 allows good forward visibility in both directions along the R Relationship between the 10 WWTP and the Proposed Pumping Stations Refer to Figure 9.2 Pumping Station Site Location Plan in Section herein which illustrates the surrounding road network, and the relationship between the proposed WWTP and the 4 no. pumping stations which form the focus of this study Impacts on the Environment Construction Phase The potential traffic impacts associated with the construction of the pumping stations will be dependent entirely on the main contractor who is appointed to construct the works, and will be a function of the contractors chosen resource levels, choice of plant, sequencing and liaison with stakeholders. Notwithstanding this, it is possible to outline potential impacts based on reasonable assumptions; these may be liable to change depending on the contractors choices. The construction stage for the 4 Pumping Stations associated with the proposed Sewerage Scheme will be controlled wholly by the contractor in charge of the works. This is expected to be in the order of 6 to 8 months. During the construction stage it is possible that up to 15 people may be employed between the 4 sites, giving an average of 4 construction workers per site. Normal working hours will be between 8.00am and 6.00pm, five days per week with possible working on Saturday mornings. Assuming each of the construction workers arrives to work by car, and assuming 4 people are employed on each site at any one time, an average of 4 cars will arrive at each site between 7.00am and 8.00am, and the same number will leave between 5.00pm and 6.00pm. During the construction phase, trucks and vans will be delivering materials to each site on a daily basis. It is estimated that this could be in the order of 3 trucks per day attracted to each site depending on the particular construction activity. 10 WWTP Waste Water Treatment Plant EPA Export :10:54:09

30 Environmental Impact Statement Section 9 - Page 27 In summary, it is expected that during the construction period, an average of up to 3 trucks per day could be arriving at and leaving each pumping station site, and up to 4 cars could arrive in the morning and leave in the evening. Temporary Diversions to Facilitate the Construction Phase Again, this will be dependent entirely on the main contractor who is appointed to construct the works. It can be predicted however that service trenches will need to be formed across the mainline carriageways which will cause disruption to road traffic. Road closures and temporary diversions will be required in any case for the construction of the sewer network for the scheme Operational Phase The potential environmental impacts generated by traffic associated with the proposed operation of the pumping stations are in relation to the existing road system and inhabitants within the surrounding area. This will apply at both the construction and operational stages. This increased volume of traffic will have potential impacts on humans such as: Increased noise and vibration levels Visual Impact Community Severance Pedestrian Stress, Delay and Amenity Cyclist Delay Driver Delay Increased Accident Potential Increased Air Pollution Increased Dust & Litter Generation The above impacts, although not necessarily significant, require consideration to determine their extent. Certain groups of people whose immune systems are suppressed, that is the very young and the elderly or those in sensitive locations i.e. hospitals, schools, etc may be affected more than others. Others who may be affected are those at home, work, walking or cycling. The impact on the above groups will depend on various factors such as: Volume of traffic Speeds and operational characteristics Composition of traffic e.g. the heavy vehicle content The perception of traffic change on humans will depend on factors such as: Existing traffic Traffic route EPA Export :10:54:09

31 Environmental Impact Statement Section 9 - Page 28 Time of day Variation of traffic volume Design and layout of roads in the vicinity Land use activities adjacent to the route A review of each of the previously noted potential impacts on humans from the traffic component of the scheme is expanded upon in Volume 2 Traffic Appendices. This information is pertinent to both the construction and operational phases of the development Expected Traffic Generation and Distribution Construction Phase As discussed previously in Section it is expected that during the construction period, an average of up to 3 trucks per day could be arriving and leaving each pumping station site and up to 4 cars could arrive in the morning and leave in the evening Operational Phase In order to assess the impact of traffic generated by the proposed pumping stations on the surrounding network, it is first necessary to predict the likely traffic volumes that will be generated by the operation of the pumping stations. It is expected that traffic generated by the operation of each pumping station will be evenly distributed throughout the day. Traffic generated by the pumping stations will be governed by the frequency of the caretaker tending to electrical and control panels which control the operation of the pumps, and the maintenance requirement of the pumping system. By liasing with pumping specialists, a conservative estimate of maintenance trip frequencies has been compiled and detailed later herein. The frequency of maintenance requirements will dictate trip generation for each site. Whilst real-time maintenance trip requirements cannot be accurately forecast, it is possible to provide a conservative projection of likely maintenance visits. As pumping technology improves and pump failure frequency reduces the maintenance trip frequency will also reduce. Noting the above, the likely maximum traffic generation to each of the 4 proposed pumping stations has been illustrated in the following Table. EPA Export :10:54:09

32 Environmental Impact Statement Section 9 - Page 29 Table 9.5 Estimated Maximum Trip Generation for each Pumping Station Site Trip Type and Assumptions Behind the Estimation Arrivals Departures Caretaker trips: This is expected to involve the caretaker calling to each pumping station twice a week to check on control panels and the operation of the pump sets. Assume worst case scenario that the caretaker calls out every day to each pumping station. 1 1 Maintenance vehicle trips: This is expected to involve a maintenance fitter in a van/pick-up truck calling to each pumping station in the order of once every 6 months with spare pump parts and to service the pumping system. The model is therefore run for the worst case day i.e. the day the maintenance vehicle is called out. Total Daily Maintenance Trips to each Pumping Station: Based on the surrounding road network and site observations, it is expected that traffic generated to each pumping station site may be split evenly between the towns of Moville and Greencastle. As demonstrated in Table 9.5 it may be assumed that traffic associated with the operation of each pumping will, at worst, result in 2 inbound and 2 outbound trips spread evenly throughout the day for each pumping station, and will represent a tiny proportion of surrounding road network flows for each pumping station site Access Arrangements for the Proposed Development Carrickarory Pumping Station This pumping station will be accessed directly via the R238 approximately 1 kilometre south west of the town of Moville. The proposed site access will be located at the apex of a curve in the R238. The existing site boundary wall will be splayed appropriately from the existing edge of carriageway to allow exit visibility from the pumping station to the left and right onto the R238 to meet visibility criteria as set out in the NRA Road Geometry handbook (design code NRA TD 41/95) which requires a desirable minimum envelope of visibility of 90 metres for access onto a major road with a design speed of 60kph. These criteria are also in full compliance with County Donegal Development Plan 2006 EPA Export :10:54:09

33 Environmental Impact Statement Section 9 - Page Development Guidelines and Technical Standards. The posted speed limit of the R238 in the vicinity of the site access is 60kph. The location of the access at the apex of the curve in the R238 also provides good forward visibility for vehicles on the R238, both to turn safely into the site and also to stop safely in advance of the site entrance as the location of the site access falls within the desirable minimum stopping sight distance of 90 metres for roads with a design speed of 60kph (NRA TD 9/00). Sufficient clearance will also be provided between the gated entrance to the pumping station fronting onto the R238 and the edge of carriageway on the R238 to allow a vehicle servicing the pumping station to pull in safely without blocking traffic on the R238 and open the gated access to the site. The pumping station enclosure will be of sufficient size to ensure that light goods vehicles used to service the site can park within without hindrance to mainline traffic, and can execute turning movements safely within the enclosure. Site access will be gained via a gate fronting onto the R River Row Pumping Station It is proposed to gain site access directly off the end of the River Row cul-de-sac. The access will be located directly across from the side of the last residential dwelling on the cul-de-sac, in an existing green area on the southern bank of the River Bredagh. Visibility down the cul-de-sac is good, with access to and from the site assisted by the proximity of the end of the cul-de-sac, which serves to slow vehicle speeds. Protocols for construction works, and maintenance access will have to be set in place prior to work starting to ensure due consideration is given to the residents and children of River Row. The pumping station enclosure is of sufficient size to ensure that light goods vehicles used to service the site can park within without hindrance to the residents, children and traffic movements on River Row Glenburnie Pumping Station It is proposed to gain access to Glenburnie pumping station off the existing car park at the end of the cul-de-sac accessing Lough Foyle. The pumping station site will occupy an existing green area adjacent to the car park and site access will be gained via a short length of new road off the car park. Service vehicles will be able to utilise the existing car park to safely park and execute turning movements during service visits. As the number of daily trips generated by the pumping stations will be minimal when compared to the quantum of existing traffic accessing the lough and residences along the cul-desac; it is not expected that pumping station vehicles will negatively impact on the cul-de-sac. There shall be a minor reduction in the capacity of the car park due to the new access road to the Pumping Station. The access road shall be used infrequently; the number of service vehicles using the car park will also be small. Therefore this will have a minor negative impact. EPA Export :10:54:09

34 Environmental Impact Statement Section 9 - Page Greencastle Pumping Station The proposed Greencastle pumping station is located in an existing car park in Greencastle, off the R241 which forms the main street of Greencastle. It is proposed to gain access to the site via the two existing car park entrances. Visibility accessing and exiting the car park is good in all directions from both car park entrances, with caution needed at the car park entrance off the access road to Greencastle Pier as there is a conflict with traffic entering and exiting the pier. Service vehicles are likely to use the adjacent parking facility without risk to other road users. One car-parking space will have to be removed to ensure permanent vehicular access to the pumping station site. There is adequate capacity in this car-park (approximately 34 car-parking spaces) so the removal of this car-parking space and the one or two vehicles requiring parking spaces during the servicing of the pumping station will only have a minor negative impact on the overall car park capacity Mitigation Measures Construction Phase In order to mitigate against potential impacts of the pumping stations due to traffic generated by the construction phase, a construction traffic management plan will be developed by the contractor(s) prior to the commencement of work on site, in consultation with stakeholders including but not limited to Donegal County Council and An Garda Siochána for agreement of relevant construction traffic management and monitoring measures. The plan will take cognisance of all road users particularly those who are vulnerable or impaired. The following general measures will apply: The construction traffic management plan will identify suitable (signed) haulage and delivery routes for HGV s, appropriate locations for marshalling of delivery vehicles, and outline requirements for banksmen; Full road closures to facilitate service crossings if required, will be carried out outside of peak hours and be kept to short durations of the order of 3 hours, with temporary or emergency reinstatement provided by the use of steel road plates to allow vehicles to traverse over open trenches under supervision. Alternatively road crossings will be constructed across half the road width at one time (where road widths permit). This will force the use of stop-go boards or shuttle traffic signals to control one-way traffic past the half crossing in each direction. Under no circumstances will road crossings be left open on the public road over night. Appropriate warning signage for the site accesses will be provided in order to alert both delivery staff and the general public of the access; this shall be discussed with Donegal County Council Road Department during the preparation of the Traffic Management Plan for the Scheme. Parking for construction traffic will take place within site curtilage or on adjacent existing car park facilities without significantly impacting on EPA Export :10:54:09

35 Environmental Impact Statement Section 9 - Page 32 other car park users. No parking is to take place on the narrow cul-desac accessing Glenburnie as this would block access to the strand area. Details of working hours will be included in the construction traffic management plan. Deliveries of materials or the exportation of spoil from sites will avoid both AM and PM peak hours, particularly in River Row and Glenburnie as River Row is highly residential and the access culde-sac to Glenburnie is quite narrow where construction traffic should avoid potential conflict with those going to or returning from schools and places of work; Construction debris (particularly site clearance, spoil removal and dirty water runoff such as dewatering or wash from concreting activities) can have a significant impact on footpaths, watercourses and roads adjoining a construction site if not adequately dealt with. There will, therefore, be a requirement for comprehensive measures as part of the plan to mitigate against the above; Banksmen will control access and egress from each site access and/or site compound; High pressure water jet washers will be provided at each site access to clean vehicles exiting the sites during any spoil removal; All loads to / from the site will be properly stowed and secured with a tarpaulin, where appropriate; Routine sweeping / cleaning of the road adjacent to the site will also be carried out. Any damage to the surrounding road network caused by construction traffic will be repaired by the Contractor and returned to it s original condition or better; Road or lane Closures (if any) will be advertised in the media and through signage on the route affected by the closure in advance of the closure; Diversions (if any) will be delineated using appropriate signage and removed when the works have been completed Operational Phase In order to minimise the traffic impact resulting from the proposed 4 No. pumping stations associated with the sewerage scheme during the operational phase, the following measures will be adopted: Ensure vehicles associated with the delivery and removal of parts are appropriately sealed and covered; Ensure appropriate perimeter protection is installed around each pumping station site to limit access by the general public; Install adequate signage and notice boards for the site; Provide adequate lighting for the site during routine service visits. EPA Export :10:54:09

36 Environmental Impact Statement Section 9 - Page 33 A number of local road network improvements will need to be made in order to facilitate the safe and efficient movement of traffic generated by each pumping station. These measures include the following: Erect warning signage in advance of all pumping station entrances in order to improve road safety and inform all road users of site entrances; Improve junction discipline at the junction of the R241 and the cul-de-sac accessing Lough Foyle by ensuring adequate visibility is provided in both directions exiting the cul-de-sac onto the R241. This may be achieved by cutting down the hedge bounding the front of the residential dwelling, which currently impedes views to the right exiting the cul-de-sac, to an appropriate height and providing improved visibility to the left by setting back the existing residential dwelling boundary wall fronting onto the R241 an appropriate distance. Also, the provision of a stop sign at the T- Junction will aid junction discipline. Provide adequate car parking space either within the pumping station site or in adjacent car parks Residual Impacts The implementation of the proposed mitigation measures will ensure that there is no significant residual environmental impact as a result of the traffic component of the proposed development Monitoring No additional post-development monitoring is considered necessary with this development Conclusion Traffic generation associated with the construction and operation of the proposed pumping stations is relatively small and will have no significant adverse environmental impacts. EPA Export :10:54:10

37 Environmental Impact Statement Section 9 - Page 34 Traffic Assessment Summary Table Potential Impacts Mitigation Measures Residual Impacts WWTP During the construction period the WWTP will generate a maximum of 15 trucks per day and 20 cars per day. The traffic impact during the operational phase will be within acceptable limits. The increased volume of traffic during the construction and operational phases will have potential impacts on humans such as increased noise and vibration levels, visual impact, pedestrian delay, and cyclist delay. Pumping Stations During the construction period the pumping stations will generate a maximum of 3 trucks and 4 cars per day. The traffic impact during the operational phase will be within acceptable limits. The increased volume of traffic during the construction and operational phases will have potential impacts on humans such as increased noise and vibration levels, visual impact, pedestrian delay, and cyclist delay. In order to mitigate against the construction impacts, a construction traffic management plan should be developed by the Contractor(s) prior to the commencement of work on site. Suggestions for this plan can be found in Section To mitigate against the traffic impacts during the operational phase a number of mitigation measures are suggested in Section In order to mitigate against the construction impacts, a construction traffic management plan should be developed by the Contractor(s) prior to the commencement of work on site. Suggestions for this plan can be found in Section To mitigate against the traffic impacts during the operational phase a number of mitigation measures are suggested in Section With mitigation measures, traffic generation associated with the construction and operation of the proposed development is relatively small and will have no significant adverse environmental impacts. With mitigation measures, traffic generation associated with the construction and operation of the proposed development is relatively small and will have no significant adverse environmental impacts EPA Export :10:54:10

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51 Environmental Impact Statement Section 10 - Page 1 SECTION 10 NOISE This section of the EIS addresses the requirements of the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). This Regulation requires that the Sanitary Authority ensures that; The WWTP is designed and constructed to ensure it avoids causing nuisance through odours or noise; The WWTP is operated and maintained to ensure it avoids causing nuisance through odours or noise; and A report is to be provided to the Environmental Protection Agency (EPA), on an annual basis, detailing the steps taken to ensure compliance with the Regulations & detailing any odour or noise incidents in respect of the WWTP Waste Water Treatment Plant Introduction The noise impacts of the proposed WWTP works on the surrounding area are likely to arise during: Construction of the Wastewater Treatment Facilities Operation of the Plant The design, construction, operation and maintenance of the plant requires to comply with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) Existing Environment The proposed WWTP site is located in a rural area to the west of the R241 regional road between Moville and Greencastle at Carnargarve. The geographical location can be described as the eastern foothills of the Inishowen Peninsula where the land slopes sharply to the sea at Lough Foyle. The area is predominantly rural with ribbon development along the road network and dispersed farm dwellings. The nearest residences to the site are a number of private residences located to the Southwest of the site, as outlined on the attached site layout drawings, houses along the R241 route which lie to the Southeast of the proposed site and dispersed rural houses to the North and West of the proposed site. There are two sports facilities located close to the site, one to the Southeast, near the cul-de-sac and another to the North. A pre-school operates in the grounds of the GAA facility to the Southeast. There is a Roman Catholic church located to the North-east of the proposed site. The site is located on a more or less level field that forms a plateau on the lower slopes of Crockaulin Mountain (~ 47m OD). Above (North) of the site the land rises sharply and there are two houses overlooking the site from this EPA Export :10:54:11

52 Environmental Impact Statement Section 10 - Page 2 prospect (~100m OD). To the South of the site the land also falls sharply to the R241 (~ 33m OD) and on to the sea at Lough Foyle. The proposed treatment plant will be located at a level of approximately 48 m OD at the Northern end of the field. This location has been chosen to maximise the distance from adjacent properties and to provide maximum screening using the natural contours of the site. The site lends itself to natural screening by means of a comprehensive landscaping plan. The location is not untypical of similar sites assessed by Biospheric Engineering Ltd in the past; in particular, Tuam Co. Galway, Bundoran Co. Donegal and Courtown Co. Wexford are similar plants in size and are located in locations with similar proximity to existing dwellings Methodology Two types of measurement were carried out at the site, on the site itself a noise meter was set up on the afternoon of the 15 th March 05 and it measured noise levels continuously until the morning of the 16 th without anyone attending at the meter (unattended measurements). A separate set of noise readings was taken using another noise meter where the noise level was measured at different locations for a shorter period of time and notes were taken of the source and character of the noise, (attended measurements). The combination of the two sets of measurements was then utilised to assess the existing noise climate in the area of the proposed development Unattended background measurements In order to determine noise levels in the area surrounding the site noise readings were taken from March 15 th 2005 to March 16 th A Bruel & Kjaer model 2238 type 1 sound level meter was located on site (Location N1) for a period of 21 hours during a normal weekday period (Tuesday to Wednesday). Figure shows the locations where noise measurements were recorded. Weather conditions at Malin Head for this period are outlined in the table below. It should be noted that the site measurement location was at the eastern side of the hills and was somewhat sheltered from the South/Southwesterly wind. While there may be some wind influence on the long term noise readings they are not deemed to be significant as local wind readings taken at the measurement locations were within the range 2m/s to 4 m/s. Table Weather Reports from Malin Head Date Rainfall Max Min Sunshine Gusts Windspeed (mm) Temp Temp (hours) knots knots 15/3/ /3/ The noise levels recorded during this period are reproduced on the attached graphs, figure and figure The L Aeq value being the average noise reading and the L A90 being what is usually considered background noise levels. EPA Export :10:54:11

53 Environmental Impact Statement Section 10 - Page 3 A summary of the long term noise levels measured at the N1 (site) are as follows in table Table Noise Level Measured on Site Date Night Period (22.00 to 08.00) Day Period (08.00 to 19.00) Evening Period (19.00 to 22.00) L Aeq db(a) L A90 db(a) L Aeq db(a) L A90 db(a) L Aeq db(a) L A90 db(a) 15/3/ /3/ Background noise levels, near the proposed WWTP are dominated by road traffic noise from the R241. Other noise sources include local traffic, agricultural activities, farm animals, aircraft overhead (Derry Airport) and natural sounds such as birdsong and wind blowing in the trees. There are no current industrial noise sources in the immediate vicinity of the WWTP. These background noise levels are typical of locations in rural Ireland that are reasonably close to human activity, i.e. towns, villages, traffic routes. The average background noise level can vary by ± 5 db during the course of the day and weather conditions can play a significant part in determining audibility of noise at any particular location. With an average noise level in the 45 to 50 dba range the area is relatively noisy for a rural location, noise levels are not high as would be the case were the site located closer to a major road or near a town. The background noise level in what would be considered a quiet rural area would normally be 10 to 15 db less than the levels measured on site, i.e. 30 to 40 dba, so the area is not a particularly quiet area Attended background Measurements In addition to the long term monitoring of noise levels on site a series of attended measurements were taken at off-site noise sensitive locations on the 15 th and 16 th March. Three noise sensitive locations were chosen to represent the properties in the vicinity of the development. The measurement locations are marked N2, N3 and N4 on the figure N2 at the crossroads to the Southwest of the site. This site was chosen as representative of the cul-de-sac area and the adjoining housing development in addition to the pre-school located at the GAA facility. N3 at the houses overlooking the site to the North. This location was chosen as representative of the locations further removed from the R241 (main noise source in the area) and representative of the sheltered locations to the North and East of the site. EPA Export :10:54:11

54 Environmental Impact Statement Section 10 - Page 4 N4 at the roadside on the R241. This location was chosen as representative of the noise climate along this road. Each site was visited three times during the monitoring period to determine the temporal changes in noise levels. Morning (30 minute measurements), Afternoon (30 minute measurements) and night (5 minute measurements) were taken at each location. Measurements were taken using a Bruel & Kjaer model 2260 type 1 sound level meter with modular real-time analysis using BZ7210 noise analysis module. The instrument was calibrated using a Bruel & Kjaer model 4231 sound level calibrator. Post Measurement analysis was carried out using Bruel & Kjaer Noise Explorer software. During measurement the height of the microphone was 1.3 metres above ground level at the sampling location. Weather data at the site location was compiled using Prosser model Weathertrend digital barometer, Rotronic model A1 Hygrometer and Silva Windwatch digital anemometer. Weather during the measuring period was as follows Table 10.3 Local Weather Date Time Barometric Pressure Temp Relative Humidity Wind mbar o C % 15/3/ : m/s S/SW 16/3/ : m/s S/SW Weather Overcast & occas. showers Sunny with occas showers EPA Export :10:54:11

55 Environmental Impact Statement Section 10- Page 5 The results of the background noise measurements are outlined on the following table; Table Noise Measurements 15 th /16 th March 2005 Start Time Location Sound Pressure Levels Comment L(A) eq 30min L(A) 10 30min L(A) 90 30min 15:02 Location N2: Crossroads to SW of site Grid ref: , Traffic noise on R241, agricultural activity, aircraft overhead, wind in vegetation, birdsong 9:12 As above As above, helicopter audible 22:03 As above (night 5 min. measurement) Traffic noise on R241 dominant 15:40 Location N3: Near house overlooking site Grid ref: , Traffic on R241 dominant with local traffic causing peaks, (pick up time at school), birdsong 9:47 As above Road traffic on R241 dominant, dog barking 22:12 As above (night 5 min. measurement) Road traffic on R241 16:14 Location N4: Roadside R241 Grid ref: , Road traffic dominant, birdsong, agricultural activity, tractors etc. 10:22 As above Road traffic dominant (30 minute traffic count 135 cars + 11 HCVs) 22:22 As above (night 5 min. measurement) Road traffic dominant EPA Export :10:54:11

56 Environmental Impact Statement Section 10- Page Baseline Ambient Noise The noise measurements are consistent with the measurements taken in a rural area. The measurements taken near the R241 (Location N4) are typical of those arising at busy regional roads and show little variation throughout the day. The measurements taken at locations N2 and N3 are more typical of those arising in rural areas. At Location N2 and N3 the closeness of the L 10 and L Aeq values indicates that the noise is steady state and influenced by steady traffic on the R241. The background level recorded (L A90 ) at the three locations needs to be noted as this is the steady state noise level that pertains for an average day. At Location N2 it can be taken to be about 43 dba for the working day. This is a relatively high background noise level and will have a significant masking effect on additional noise sources. At Location N3 the level was 46 dba indicating that the noise from the R241 dominates the noise climate in the area. At Location N4 the background noise level remains relatively high due to the level of traffic on the R241. The background noise level measured on the proposed site reflected the values measured at the three attended locations. The actual measurement location chosen was however sheltered from a direct line of sight of the R241 (noise barrier effect) and the lowest recorded value of the L A90 at this location was 38 dba. This level, while the lowest recorded, is still relatively high for a rural area. Two elevated noise events were recorded at the site location. One occurred at sunset and the other just before dawn. The events can be attributed to birds returning to roost in the evening and awakening in the early morning. The relatively high background noise level at this location can be accounted for by the traffic levels on the R241 and the proximity to Derry with consequent road traffic, shipping activity and air traffic Impacts on the Environment Construction Phase Topsoil shall be removed from all working areas of the site and stored in stockpiles for later reuse. Excavation for tanks, foundations and services shall then be undertaken to the required formation levels. Surplus excavated material shall be used to form landscaping mounds in accordance with the landscaping plan. The early stages of construction may require some rock-breaking activity in order to get pipes and tanks to the required levels. A site access road will be developed from the site entrance to the heart of the site. This road will be the only entrance route into the operational WWTP from a public road. Initially this road will be constructed of compacted hardcore but will at all times maintained in good condition and will be hard surfaced with bitumen surface coating as soon as is practicable to minimise construction noise emissions due to vehicles travelling over rough terrain. EPA Export :10:54:12

57 Environmental Impact Statement Section 10- Page 7 Construction activity on site will take the form of reinforced concrete construction and assembly of equipment. A control building, a blower building and sludge building will be constructed using conventional construction techniques. None of the site operations will be particularly noisy by its nature and any noise events will be limited to the short duration of the construction period. Construction of the inlet and outfall pipes will be carried out during the day working period (07:00 to 19:00, Monday to Friday and 07:00 to 16:00 on Saturdays). This activity may also require the use of noisy equipment such as a rock-breaker on the road accessing the site. The duration of this activity in any one location will be limited to a short period. Appropriate noise control measures such as those outlined in British Standard 5228 Part 1, Noise & Vibration Control on Construction and open sites will be in place during the construction period Operational Phase Processing Plant and Machinery The processing plant and machinery that will be used on site are not specified in detail but outline descriptions indicating the likely sources of noise resulting from the use of such equipment is outlined below. The sound power levels are based on estimates provided in Engineering Noise Control Theory and Practice, 3 rd ed., Bies, & Hansen, Spon Press, London, 2003 and measurements taken at similar plants by Biospheric Engineering Ltd. Inlet works Inlet balancing tanks usually comprise of reinforced concrete storage tanks with an inlet and an outlet pipe. The outlet pipe is usually submerged and the inlet pipe is usually fed through a screening mechanism. The noise sources on this plant item comprise the sound of wastewater rushing into the system (broadband noise like a small waterfall) and the motor/mechanism of the screen. The motor on this plant is likely to be less than 3kW in capacity and not particularly noisy. A more significant motor may drive a maceration device that is required to break up the solid matter contained in the wastewater. Typical sound power levels L WA for inlet works are 90 db. Control Building The control building comprises the actual control room, employee facilities and usually incorporates some of the plant items such as pumps or sludge presses depending on the site configuration. The building is normally constructed with a cavity wall construction, with acoustic doors fitted to the areas where noisy plant items may be located. On some sites the control room is virtually quiet, in this model the control room is assumed to have some mechanical plant and a sound power levels L WA of 88 db is assumed as a worst case scenario. EPA Export :10:54:12

58 Environmental Impact Statement Section 10- Page 8 Aeration Tank Aeration tanks comprise large reinforced concrete structures in which the wastewater is stored for an extended period while compressed air is pumped in at the bottom of the tank to treat the water. The main noise source in this plant item is the bubbling noise of the air as it mixes and aerates the wastewater. A sound power levels L WA of 93 db is assumed for this item of plant Blower Building The air blowers are the single loudest noise source on any WWTP site. This is due to the power of the motors and the nature of the mechanical plant required to produce large volumes of air at pressure to aerate the tanks. It is normal that the internal noise in the blower building be such that hearing protection is required for the operators (> 90 dba sound pressure level). Due to the high noise levels generated by the blowers it is normal to construct the blower building with no windows and to provide appropriate acoustic screening to the doors and to any air intake grilles. The provision of this acoustic screening is normally such that the noise level external to the building is reduced to dba. Mitigation measures will be required on this development to ensure appropriate acoustic screening is carried out. Sludge Thickener The sludge thickening tank is not an inherently noisy operation. Any motors involved are small in comparison with the remainder of the plant. No significant noise emissions will arise and a sound power level of 86 dba is assumed. Clarifier Tank The clarifier tank comprises a large reinforced concrete tank in which the wastewater is retained for an extended period to allow any suspended solids to settle to the bottom of the tank. The tank has a rotating sludge collector arms that move at a slow pace driven by a small electric motor. The noise from such equipment is not significant and a sound power of 79 dba is assumed. Storm Tanks The storm tanks are not generally associated with significant noise emissions. In this case (worst case scenario) they have been assigned a sound power level of 88dBA Generator The nature of the WWTP is such that even with a mains power supply, a back-up diesel generator, if not permanently on site, may be required on site from time to time to ensure the plant can operate in the event of power failures. The nature of these power failures is such they are likely to occur for a limited duration and on a limited number of occasions during the year. EPA Export :10:54:12

59 Environmental Impact Statement Section 10- Page 9 Any generator used on site can be enclosed in a silencing enclosure (or a building) limiting noise emissions. The extent of use of the generator is not such that the noise emissions are considered in this model. Hours of Operation The wastewater treatment plant is an essential community service and will be required to be operational 24 hours every day on a year round basis. Environmental Design Criteria The normal criteria adopted by planning authorities for this type of development in the past has been that proposed for facilities required to obtain Waste or Integrated Pollution Control Licences from the Environmental Protection Agency. Based on licences for similar projects in the past the noise limits for the development are likely to be: Table 10.5 Noise Emissions: (measured at the Noise Sensitive Locations) Day db(a) L Aeq (30 minutes) Night db(a) L Aeq (30 minutes) With no audible tonal or impulsive components As the WWTP will run on a 24 hour basis the limiting criteria is the night time value of 45 dba at noise sensitive locations. As outlined above the blowers are a significant noise source with a tendency to generate tonal noise. In order to allow for a possible tonal quality and the maximum penalty under the Joint Nordic Tonal Assessment the LAeq value needs to be below 39 dba at all noise sensitive locations. This will ensure compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) Noise Prediction Model The noise sources on site are outlined in the following table. This data is based results from similar equipment in Biospheric Engineering Ltd s database and on Engineering Noise Control Theory and Practice, 3 rd ed., Bies, & Hansen, Spon Press, London, 2003 and is also shown on Figure This data was then used to prepare a noise prediction model for the proposed development. The sounds are taking into account acoustic abatement measures. The noise prediction model chosen was constructed using Bruel & Kjaer Predictor Package. The Predictor software package is a comprehensive acoustic modelling system. The program calculates the received noise level from specified sources, propagated via intermediate obstacles and media, based on national and international standards. Consequences of noise reduction measures can be rapidly assessed and it is possible to compare calculated, measured and permitted values. EPA Export :10:54:12

60 Environmental Impact Statement Section 10- Page 10 Model data is held in a database under the complete control of Predictor. The types of item in a model include sound sources, objects and sound receivers. Each item has positional information, which relates it to the base area in 3-D terms. The base area is usually superimposed upon a 2-D topographical map, the background, which is used to align each item in the model relative to an actual survey of the area under study. The models in the variants can be calculated to predict the sound pressure levels at the receiver points. The calculation for each model is done with a specific Emission point Description Octave bands (Hz) Sound Power Levels db (unweighted) per band Ref Quantity k 2k 4k 8K 1 1 Inlet works Control Building Aeration Tank Blower Building Sludge Thickener Clarifier Tanks Storm Tanks Generator calculation method like ISO /2. Sound Sources used to prepare the prediction model The model based on the sources outlined above is a comprehensive model containing sound power data. A three dimensional receptor grid for the area contains over 2000 receptor points which enables noise contour levels to be plotted for the area surrounding the proposed development. Sound Pressure Levels are normally stated to the nearest db due to measurement uncertainty. The desired result is therefore a sound pressure level of dba or less at noise sensitive locations. The ISO calculation method is implemented in Predictor as 2 separate modules. ISO /2 industry and ISO /2 road traffic. This is done because of the difference in type of sources, difference in spectral sound power of roads per period and the difference in noise policy of authorities between industry and road traffic. When creating a model the user has to choose between the 2 ISO module types. This model has been prepared using the ISO /2 industry module. The following standards are used in the ISO industry calculation method: ISO Acoustics Attenuation of sound during propagation outdoors. Part 1: Calculation of the absorption of sound by the atmosphere; EPA Export :10:54:12

61 Environmental Impact Statement Section 10- Page 11 ISO Acoustics Attenuation of sound during propagation outdoors. Part 2: General method of calculation; VDI 2571 Schallabstrahlung von industriebauten. This German method is used to calculate the directivity of point sources for noise emitting facades and roofs. Noise Prediction results The results of the noise prediction model are plotted using noise contour levels on the aerial photograph in Figure These results assume that the noise abatement protocols have been implemented at the WWTP. While the noise levels inside the WWTP perimeter are high the levels reduce rapidly with distance. The geographical layout of the WWTP, the proposed landscaping works and the natural attenuation due to the ground contours also assist in mitigating the noise levels. The model indicates that the proposed WWTP, even when all equipment items are operating at maximum (noise) output will not exceed the guideline of 55 dba at the nearest noise sensitive location during the day. Indeed the predicted level at most residences in the area will be below 30 db(a). The level at all residences will be below the recommended limit of 39 db(a) at all times, thus meeting the Environmental Protection Agency guideline limits and in compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). Impact of noise prediction results The models indicate that noise in the general area of the site is determined by the traffic on the R241. Noise levels from the WWTP operations can be maintained below the acceptable limit of 39 dba at all of the noise sensitive locations. While meeting the limit set by the Environmental Protection Agency, it does not mean that the noise from the WWTP will be inaudible. The noise level for properties located on or near the R241 will not change with the operation of the WWTP. Properties located to the north of the proposed development may find that the plant is audible under certain climatic conditions. It is important therefore that considerable attention is given at design stage to the enclosure of noisy equipment and that no tonal noise emissions are evident at noise sensitive locations Mitigation Measures Construction contract documentation will include provision for limiting noise emissions during the construction phase by requiring the contractor to implement noise control measures as outlined in British Standard 5228 Part 1, Noise & Vibration Control on Construction and open sites where appropriate. Limit noisy construction works to to weekdays with Saturday working from hours (construction activities not involving the EPA Export :10:54:12

62 Environmental Impact Statement Section 10- Page 12 use of mobile construction equipment could be carried out outside these hours, subject to a maximum noise level of 45 dba (L Aeq 5 minute ) at the nearest occupied residence. Ensure rock-breaking and other noisy activities are adequately screened from the adjacent sensitive locations. Use modern, silenced and well-maintained equipment conforming to EU directive 2000/14/EC Noise emission in the environment by equipment for use outdoors. Shut down equipment when not in use, where practicable. Site semi-static equipment such as generators, mixers, and compressors as far away as possible from sensitive locations and ensure that the orientation is the optimum for low noise. Ensure that workers are given appropriate training with respect to minimising noise and disturbance in the context of the BS 5228 assessment for the works. Earth mounds and landscaping works erected at the site entrance and around the site boundary will provide acoustic as well as visual screening. Roads within the site to be paved and maintained to provide level surfaces and have as low a gradient as possible. The contract documentation shall include an acoustic specification clause as follows: Noise emissions from the wastewater treatment works, with all plant items operating at designed capacity, shall not exceed L Ar15minutes 45 dba re 20 upa at the site boundary at any time, where L Ar is the rated noise level including tonal penalties calculated using the Joint Nordic Method for Tone Assessment. The design of the Blower Building and the Generator Building shall be approved by a suitably qualified Acoustic Consultant. Prior to handover of the wastewater treatment plant a noise survey shall be carried out by a suitably qualified Acoustic Consultant, independent of the design and build team, confirming compliance with the requirements outlined above. The design of the scheme shall be in compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). The requirements of this clause are designed to ensure that the successful tender includes design responsibility and the appropriate professional expertise to meet this acoustic specification. EPA Export :10:54:12

63 Environmental Impact Statement Section 10- Page Monitoring Proposals It is proposed to monitor noise on an annual basis in accordance with the Environmental Protection Agency Environmental Noise Survey Guidance Document. Monitoring will be carried out during the day, evening and night period as the equipment operates on site on a 24 hour basis. Monitoring and reporting to the EPA shall also be carried out in compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) Residual Impacts There is no significant residual environmental impact as a result of the noise component of the proposed development and the scheme will be compliant with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). During the construction phase buildings and process tanks will be constructed using conventional construction techniques. This will involves excavation and some rock breaking which maybe noisy. The actual construction of the buildings and tanks will not be particularly noisy by its nature and any noise events will be limited to the short duration of the construction period. The Contractor shall be required to implement noise control measure as outlined in the British Standard 5228 Part 1, Noise and Vibration Control on Construction and open sites. During the operation phase there will be noise emitted from the WWTP s. The noise model indicates that even when all the equipment items are operating at maximum, noise output will not exceed the guideline of 45 dba at the nearest existing noise sensitive location during the night. Indeed, the model also demonstrates that the maximum noise output will not exceed the recommended noise criterion of 39 dba. The design of the plant will be supervised by a competent Acoustic Consultant who will ensure that the plant design is such as to minimise noise emissions, that it will comply with the recommended limit and that it will comply with the Regulations. The geographical layout of the WWTP, the construction of earth berms and landscape works, and the natural attenuation due to the ground contours also assist in mitigating the noise levels Pumping Stations Introduction Four pumping stations are proposed for the Moville and Greencastle Sewerage Scheme, three small type and one large type. The smaller pumping stations will be located at Carrickarory, Greencastle and Glenburnie. At each of these sites there will be an underground pump sump, valve chambers and two metal kiosks (one for the pumping controls and one for the caretakers equipment). The kiosks will be located above ground. The submersible pumps will be located in the pump sump. EPA Export :10:54:12

64 Environmental Impact Statement Section 10- Page 14 The large pumping station is proposed to be located at River Row in Moville. The large pumping station will include a bungalow style building with blockwork cavity walls and a tiled roof. There shall be a large underground pump sump and storm tank constructed in reinforced concrete. The building will house the ESB supply and the odour, telemetry and SCADA equipment Existing Environment River Row, Moville This location is at the end of a cul-de-sac of houses facing towards the R241. The level of the site is however much lower than the level of the R241. The area can be described as traffic free as only local traffic accesses the area, however the noise climate of the area is dominated by road traffic from the R241. A filling station and shop located west of the area on the R241 was a significant source of noise as it overlooks the area and is quite busy, even in the late evening/night. A nearby soccer pitch (which was not in use at the time of the survey) could give rise to increases in traffic levels at times Carrickarory This location is at roadside on the western side of the R241. The area can be described as heavily trafficked with significant activity taking place on the nearby pier resulting in noise from boats and loading/unloading activity. The noise climate of the area is dominated by road traffic from the R241. The pumping station at this location will comprise an underground chamber with metal kiosks at ground level Greencastle This location is in the car-park north of the harbourmasters office in the quay area. The port at Greencastle is a busy fishing port and also operates as a ferry port with a roll-on/roll-off service across the mouth of the Foyle. The result is a reasonably high noise level at all times in the area. The pumping station at this location will comprise an underground chamber with metal kiosks at ground level Glenburnie This location is adjacent to a small beach on the western shore of Lough Foyle. The area is accessed via a narrow public road and is quite popular in the Summer time. The main navigation channel into Derry port is located a short distance offshore. The pumping station at this location will comprise an underground chamber with metal kiosks at ground level. EPA Export :10:54:12

65 Environmental Impact Statement Section 10- Page Methodology Noise measurements were taken at each of the proposed pumping station locations on the 14 th July Readings were taken in both the daytime and night time periods. A Bruel & Kjaer model 2260 type 1 sound level meter was used, having been calibrated with a Bruel & Kjaer type 4231 calibrator before and after each set of readings. No appreciable drift in calibration was noted. Weather conditions were as follows: Dry/Sunny, 2/8 cloud cover, 1030 mbar, 21 o C, 46% Relative Humidity, Wind 0.5m/s North easterly. Table 10.6 Noise Measurement Results Location Time, Period db(a) L Aeq L 10 L 90 Glenburnie Day: Night: Carrickarory Day: Night: River Row Day: Night: Greencastle Day: Night: Noise levels at all four locations are significantly influenced by traffic levels on the R241. At Greencastle and Carrickarory the noise climate is also influenced by port activity nearby. It is clear that the background (L 90 ) level at night is of the order of 35 to 40 db(a) remote from the traffic and pier noise and is above 40 db(a) where traffic noise is dominant. EPA Export :10:54:13

66 Environmental Impact Statement Section 10- Page Impacts on the Environment Potential noise emission levels Noise emissions from the pumping stations are not particularly significant. The primary noise source is located under the ground and the concrete containment structure provides good acoustic screening for the source. Biospheric Engineering Ltd. have previously measured noise emission levels from four submerged pumping stations at Courttown Co. Wexford. Typical noise emission levels attributable to the pumping stations only are 40 db(a) at ground level just above the pumping station. At this emission level, the pumping stations would in effect be inaudible at the four proposed locations. Noise emission levels from sewerage treatment plants and pumping stations are more or less constant throughout the 24 hour period. Occasional noise due to cleaning and maintenance can be disregarded as it has no long term effect. The critical factor is therefore noise emission levels at night, in particular noise emissions during the quiet period Acceptable noise limits Noise emissions during the short construction phase can be addressed by way of mitigation. For the operational phase, the Environmental Protection Agency guideline value of 45 db(a) at night is a reasonable level limit. Were this level to be adopted it would be possible to hear the pump noise (when outdoors, close to the pumping station) at Greencastle and Glenburnie. It is less likely at the other two locations. It will not be possible to hear the pumping station indoors at any of the locations. It is important to note however that some pumping stations can tend to emit a tonal noise. This can be particularly bothersome at night. The specification for the pumping stations should include a prohibition on any tonal noise emissions Mitigation Measures The following noise mitigation measures are proposed; Construction contract documentation will include provision for limiting noise emissions during the construction phase by requiring the contractor to implement noise control measures as outlined in British Standard 5228 Part 1, Noise & Vibration Control on Construction and open sites where appropriate. Limit noisy construction works to to weekdays with Saturday working from hours (construction activities not involving the use of mobile construction equipment could be carried out EPA Export :10:54:13

67 Environmental Impact Statement Section 10- Page 17 outside these hours, subject to a maximum noise level of 45 dba (L Aeq 5 minute) at the nearest occupied residence. Ensure rock-breaking and other noisy activities are adequately screened from the adjacent sensitive locations. Use modern, silenced and well-maintained equipment conforming to EU directive 2000/14/EC Noise emission in the environment by equipment for use outdoors. Shut down equipment when not in use, where practicable. Site semi-static equipment such as generators, mixers, and compressors as far away as possible from sensitive locations and ensure that the orientation is the optimum for low noise. Ensure that construction workers are given appropriate training with respect to minimising noise and disturbance in the context of the BS 5228 assessment for the works. The contract documentation should include an acoustic specification clause as follows: Residual Impacts Noise emissions from the pumping station works, with all plant items operating at designed capacity, shall not exceed L Ar15minutes 45 dba re 20 upa at the site boundary at any time, where L Ar is the rated noise level including tonal penalties calculated using the Joint Nordic Method for Tone Assessment. Prior to handover of the plant a noise survey shall be carried out by a suitably qualified Acoustic Consultant, independent of the design and build team, confirming compliance with the requirements outlined above. The noise climate in the area of the proposed pumping stations is determined by road traffic noise and port activity. The measured background noise levels are of the order of 40 db(a) at all four locations. Night time noise levels represent the worst case scenario as the pumping stations will operate on a 24 hour basis. Mitigation measures including an acoustic specification clause for the design of the pumping stations limiting noise emission levels will provide adequate protection against a significant noise impact from the proposed Pumping stations. EPA Export :10:54:13

68 Environmental Impact Statement Section 10- Page Traffic and Noise Waste Water Treatment Plant The impact of traffic to and from the WWTP can be gauged from the most recent traffic count data. Donegal County Council conducted an automated traffic count on the R241 between Moville and Greencastle for the period 6 th to 14 th March 2006 inclusive. Traffic volumes varied from 1650 vehicles per day to 2100 vehicles per day, with peak hourly traffic varying from 150 vehicles to 165 vehicles per hour during peak hour. In accordance with the traffic section of the EIS (Section 9, table 9.3) traffic to and from the WWTP during the operational phase will result in a worst case scenario of 26 vehicles movements in the evening peak hour. In comparison to peak traffic volumes of 160 vehicles per hour, this represents a 16% increase in traffic levels. A more likely scenario is that there are less than 10 vehicle movements coinciding with peak hour or a 6% increase in peak flow traffic. With regard to noise levels, using the UK Department of the Environment Calculation of Road Traffic Noise (CRTN) as recommended by the National Roads Authority, the noise level during peak hour will increase slightly. The actual increase will be db. A noise level increase of less than 3.0 db is regarded as barely noticeable, in such circumstances the impact of the traffic to and from the WWTP will have practically no impact on noise levels in the area Pumping Stations Traffic to and from the Pumping Stations will result in a worst case scenario of 4 vehicles movements per peak hour (Section 9, table 9.5). In comparison to peak traffic volumes of 160 vehicles, this represents a 2.5% increase in traffic levels. There may be a more noticeable impact on the local access roads, but the overall impact is minimal. With regard to noise levels, using the UK Department of the Environment Calculation of Road Traffic Noise (CRTN) as recommended by the National Roads Authority, the noise level during peak hour will increase slightly. The actual increase will be 0.11 db. A noise level increase of less than 3.0 db is regarded as barely noticeable, in such circumstances the impact of the traffic to and from the Pumping Stations will have practically no impact on noise levels in the area. EPA Export :10:54:13

69 Environmental Impact Statement Section 10- Page 19 Noise Assessment Summary Table Potential Impacts Mitigation Measures Residual Impacts WWTP Construction Noise: Construction activity on site will take the form of excavation, rock breaking, building & reinforced concrete construction and assembly of equipment. Transport of materials and equipment to, from & around the site. Operational Noise: Noise from the WWTP during operation. The plant is operated 24 hours a day. Pumping Stations Noise emissions from the pumping stations are not particularly significant. The primary noise source is located under the ground and the concrete containment structure provides good acoustic screening for the source. Occasional noise due to cleaning and maintenance can be disregarded as it has no long term effect. The PS are operational on a 24hour basis. Construction Noise: Special noise control measures outlined in an International Noise Control Standard will be implemented. Working hours defined. Operational Noise: The design of the plant will be supervised by a competent Acoustic Consultant. Plant design to comply with strict limit (45 dba re 20 upa at the site boundary at any time). The geographical layout of the WWTP, the construction of landscaping mounds & planting, and the natural attenuation due to the ground contours also assist in mitigation. The scheme shall be designed, constructed, operated & maintained in accordance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations Construction Noise: Special noise control measures outlined in an International Noise Control Standard will be implemented. Working hours defined. Operational Noise: The design of the PS will be supervised by a competent Acoustic Consultant who will ensure the PS design is such as to minimise noise emissions and comply with strict limit (45 dba re 20 upa at the site boundary at any time). With mitigation measures the noise generation associated with the construction and operation of the WWTP is relatively minor and will have no significant adverse environmental impacts. With mitigation measures the noise generation associated with the construction and operation of the Pumping Stations are relatively small and will have no significant adverse environmental impacts. EPA Export :10:54:13

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74 Environmental Impact Statement Section 11- Page 1 SECTION 11 ODOUR This section of the EIS deals with Air Quality and specifically the odour impact of: The WWTP at Carnagarve The 4 No. pumping stations The full report on Odour is included in Volume 2 - Appendices to the EIS Methodology Odours from waste water treatment plants (WWTP) and pumping stations arise mainly from the uncontrolled anaerobic biodegradation of sewage to produce unstable intermediates. The Full Report (Volume 2 - Appendices) describes in detail how odours are generated at waste water facilities treatment plants and pumping stations and the nature and characteristics of the odours. The odour impact assessment has been carried out to meet the requirements of the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). These Regulations require that the Sanitary Authority ensures that; The WWTP is designed and constructed to ensure it avoids causing nuisance through odours or noise; The WWTP is operated and maintained to ensure it avoids causing nuisance through odours or noise; Assessment of Odour Impact Atmospheric dispersion modelling has been applied to the assessment and control of odours for many years. These models can effectively be used in three different ways: firstly, to assess the dispersion of odours and to correlate with complaints; secondly, in a reverse mode, to estimate the maximum odour emissions which can be permitted from a site in order to prevent odour complaints occurring; and thirdly, to determine which process is contributing greatest to the odour impact and estimate the amount of required abatement to reduce this impact within acceptable levels. Odour Impact & Annoyance criteria. Odour impact and annoyance criteria are discussed in detail in the Full Report (Volume 2 - Appendices). In keeping with Irish EPA, English and Dutch recommendations, all residential dwellings should be located outside the 3 Ou E m -3 contour for the 98 th percentile in one worst case meteorological year as determined by atmospheric dispersion modelling software Waste Water Treatment Plant - Odour In summary the main sources of odour emissions from WWTPs are waste water screening, grit separators (i.e. Inlet works), primary treatment processes and sludge handling processes. With the exception of aerobically stabilised sludge s, sludge residues are the primary sources of odour emissions. The secondary EPA Export :10:54:13

75 Environmental Impact Statement Section 11- Page 2 treatment stage at most municipal waste water treatment facilities and certainly at the Moville and Greencastle plant, will be an aerobic biological process with a low potential for odour generation. During the course of the study background H 2 S and Gas Chromatography Mass Spectrometry (GCMS) were undertaken at various locations around the proposed WWTP site (refer to Fig for locations). The purpose of this monitoring exercise is to provide comparison data before and after the proposed development. The monitoring indicated that a range from 4 to 37 Ou E m -3 existed as H 2 S odour at all the monitoring locations but no characteristic rotten egg odour was detected by the visiting odour consultant. In terms of TVOC (Total Volatile Organic Carbons) the concentration levels in the vicinity of the site were found to be low with all locations recording a concentration of less than ugm -3. The predominate VOC s characterised in the vicinity of the WWTP included aromatic, long chain hydrocarbons and alkanes. These are typical from traffic and diesel like emissions. The results of the monitoring are contained in Table 11.9 and Tables to in the Full report (Volume 2 Appendices) Indicative WWTP Operation All flow arriving at the WWTP will pass through the screening chamber and grit removal chamber. A storm overflow chamber located downstream of this will allow flows up to 59 l/s (3 times dry weather flow - DWF) to pass to the Works for full treatment. During storm events the excess flow will gravitate to the Storm Tank for storage and will be pumped back to the Works for treatment once the storm has abated. Flows in excess of the capacity of the Storm Tank will be directed to the Outlet Chamber. The main flow from the Works Pumping Station will flow through the Process tanks (such as the Aeration Tanks and Clarifier Tanks) and through the UV Disinfection unit. Treated effluent will discharge via an outfall pipe to the Lough. Storm over flow will also discharge via the outfall pipe on rare occasions when the Storm Tank capacity is exceeded. Sludge from the Clarifier Tanks will flow to a Sludge Pump Sump. This sump will contain two sets of pumps, one to pump return sludge on a continuous basis to the Aeration Tanks, the other to pump excess sludge to Sludge Thickening Tank. Sludge from the Moville/Greencastle WWTP will be thickened and dewatered onsite and the dried solids are transported to Letterkenny Sludge Treatment centre for further treatment. Sludge Treatment will include two phases: thickening of the sludge in the Sludge Thickening Tank and dewatering of the thickened sludge by means of a filter belt press or similar. Details of the individual potential sources within the WWTP; their related odour potential and methods of minimising and treating odour emissions are described in detail in the Full Report (Volume 2 - Appendices). The different distances and directions that the proposed WWTP operation is located from the neighbouring dwellings are represented in Figure As can be observed the closest residences is approximately 229 metres from the proposed WWTP operations in a southerly direction. EPA Export :10:54:14

76 Environmental Impact Statement Section 11- Page Impacts on the Environment - WWTP A worst-case odour-modelling scenario was chosen to estimate worst-case odour impact from the proposed Moville/Greencastle WWTP. Two odour emission scenarios were developed in respect of the proposed design with and without odour abatement. The odour emission rates and specified source characteristics were input into the atmospheric model in order to determine any significant odour impacts. Scenario 1 Odour assessment with no abatement Scenario 2 Odour assessment with abatement measures Table Comparison in odour emission reduction for Scenarios 1 and 2 for the proposed WWTP in Moville/Greencastle, Co. Donegal Scenario identity Odour emission rate (Ou E s -1 ) Percentage difference between Scenarios (%) Scenario % Scenario % The overall increase in odour emission rate in the immediate location due to the proposed Moville/Greencastle WWTP is 8975 Ou E s -1. Through the implementation of odour abatement strategies the odour emission rate from the proposed WWTP can be reduced by 63.81%. Since the most hedonically offensive odours are abated (inlet works, return activated sludge and sludge handling processes), no significant odour impact will be perceived from the residual odour as these residual odours are significantly less offensive and more dilutable in comparison with the sludge handling and inlet works process odours. Due to the increased risks associated with the pumping of return activated sludge, it is assumed that the headspace odourous air will be extracted and abated in the odour control plant. All odour emission data was obtained for a compilation of library data based on WWTP s within Ireland, UK and Germany. As stated above and in the Full Report (Volume 2 Appendices) the odour annoyance criterion adopted will be that all residential dwellings should be located outside the 3 Ou E m -3 contour for the 98 th percentile in one worst case meteorological year. The 3 Ou E m -3 contour for the above two scenarios was modelled and the impacts are as follows; Scenario 1 Proposed Moville/Greencastle WWTP without abatement protocols. The plotted odour concentrations of 3.0 Ou E m -3 for the 98 th percentile for the proposed Moville/Greencastle WWTP operation without abatement is illustrated in Figure As can be observed, it is predicted that odour plume spread is radial with a diameter of approximately 300 metres. In accordance with the odour annoyance criterion and in keeping with current recommended odour EPA Export :10:54:14

77 Environmental Impact Statement Section 11- Page 4 annoyance criterion in this country, some short-term complaints may be registered by residents living in the vicinity (south) of the proposed WWTP if no odour abatement is installed especially during warmer summer conditions. As this would not ensure compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) odour abatement strategies are therefore recommended Scenario 2 Proposed Moville/Greencastle WWTP with abatement protocols. The plotted odour concentrations of 3.0 Ou E m -3 for the 98 th percentile for the proposed Moville/Greencastle WWTP operation with considered abatement protocols implemented is illustrated in Figure As can be observed, it is predicted that odour plume spread is not significant with any perceived odour remaining within approximately 20 metres of the boundary. In accordance with the odour annoyance no complaints should be registered by residents living in the vicinity of the proposed WWTP thus ensuring compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) Comparison between odour plume dispersal before and after the implementation of odour abatement Figure illustrates comparison between odour plume spread from the proposed WWTP with and without the installation of considered abatement protocols. As can be observed, an approximate 80-metre reduction in odour impact distance can be achieved through installation of considered odour abatement protocols. It is important to note that those odour sources abated would be considered the most hedonically offensive within the proposed WWTP in comparison to other odour sources such as aeration tank odours and therefore the risk of odour impact is significantly reduced Summary (WWTP) A worst-case odour emission scenario was modelled using an atmospheric dispersion model with 3 years worth of hourly sequential meteorology data representative of the study area. A worst-case meteorological year and worstcase odour emission data was used to predict any potential odour impact in the vicinity of the proposed WWTP. Odour impact potential was discussed for the proposed operation of the WWTP with and without the implementation of considered abatement protocols. It was concluded that: During proposed operation without considered abatement protocols implemented, some short term complaints may be registered by residents in the vicinity of the WWTP during warmer summer conditions; Following the installation of considered abatement protocols, there should be no significant odour impact in the vicinity of the WWTP. Greater than an 80-metre odour impact reduction can be achieved through the implementation of odour abatement protocols. The proposed WWTP operation should not exceed the odour emission rate of Ou E s -1. All odour sources located within the inlet works and EPA Export :10:54:14

78 Environmental Impact Statement Section 11- Page 5 sludge handling processes should be abated in order to prevent the emissions of hedonically offensive odours. The implementation of the above odour abatement strategies will therefore ensure compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) Mitigation Measures Wastewater Treatment Plant The following recommendations are proposed: All odour abatement and minimisation procedures should be implemented throughout the proposed waste water treatment plant in order to prevent any odour nuisance in the surrounding area. These include; Avoid turbulence at the inlet works, weirs and when handling sludge s and return liquors. Sewage discharged from a rising main is more likely to be anaerobic (i.e. odourous), particularly during hot weather. Inlet covering and chemical dosing may be necessary. Minimise the retention of sewage under anaerobic conditions, especially in anoxic, balancing and storm tanks to prevent the formation of odourous compounds. Avoid accumulation of floating debris and persistent sediments in channels and holding tanks by design. Maintain minimal sludge delay in handling and treatment stages by design. Avoid exposure of untreated sludge to the atmosphere. Enclosed units should be sealed and vented to odour abatement systems. Provide storage provisions on site for odour prevention medium and chemicals. Ensure clear and concise odour management plans are produced for plant operation and abatement systems (i.e. system operation and maintenance) (Sheridan, 2002). The proposed WWTP should not exceed the odour emission rate of Ou E s -1. Abatement will ensure that odour concentrations will not exceed the recommended level of 3ouE m -3 at the nearest odour sensitive location. Maintain good housekeeping practices (i.e. keep yard area clean, eliminate floating debris within aeration tanks, etc.), closed-door management strategy (i.e. to eliminate puff odour emissions from sludge dewatering building) and implement an odour management plan for the operators of the WWTW s (i.e. for preventative maintenance of odour abatement systems, etc.). EPA Export :10:54:14

79 Environmental Impact Statement Section 11- Page 6 Avoid accumulation of floating debris and persistent sediments in channels and holding tanks by design (i.e. flow splitters and secondary sedimentation tanks, etc.) Ensure exhaust chimney height and efflux velocity of abatement systems are situated away from buildings and have a minimum stack height of 3 to 5 metres and efflux of no less than 10 m s -1. Enclose and seal all inlet works, sludge handling processes, distribution chamber and pump sumps and negatively extract odours to an odour control system. Operate WWTP within specifications to eliminate overloading and under loading, which may increase septic conditions within the aeration basins. Compliance with the requirements of the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005) odour abatement strategies are therefore recommended. Donegal County Council will ensure that the recommended mitigation measures are implemented Pumping Stations - Odour The rate of release of odourous compounds into the atmosphere at pumping stations is influenced by: 1. Long residence time of sewage in sewer; 2. Temperature of mixed liquor (increased temperature causes increased anaerobic conditions and volatilisation of odourous compounds); 3. The concentration of odourous compounds in the liquid phase exposed to air; 4. Processes that generate surface turbulence; 5. Total air/surface wastewater interface area; 6. Maintenance of oxygen rich conditions within the sewer network and pumping station. Details of the odour producing mechanisms in pumping stations and rising mains their related odour potential and methods of minimising and treating odour emissions are described in detail in the Full Report (Volume 2 - Appendices). Background H 2 S and GCMS monitoring was carried out at various locations around the pumping station sites. The locations are shown on Figs to The monitoring results are contained in Tables to in the Full report (Volume 2 Appendics). No elevated ambient H 2 S concentrations were detected at the boundary of the proposed Pumping station sites at Carrickarory, Moville, Greencastle and Glenburnie on the day of monitoring with all levels EPA Export :10:54:14

80 Environmental Impact Statement Section 11- Page 7 within the recommended WHO guideline value. A distinctive sea and fish odour was noted by the visiting odour consultant at the proposed Pumping station locations in Moville and Greencastle, respectively. A large and varied range of speciated Total Volatile Organic Compound s (TVOC s) were detected in the ambient air at each proposed Pumping station. These are mainly associated with background concentration levels and traffic derived. The highest TVOC was measured in Greencastle which would correspond with high traffic quantities and diesel based emissions from the harbour. The TVOC concentrations were 116, 139 and 225 µg/m 3 at Carrickarory, Moville and Greencastle respectively Impacts on the Environment Pumping Stations A worst-case odour-modeling scenario was chosen to estimate the worst-case odour impact from the proposed Pumping stations. Odour impact predictions from the Pumping stations have been based on maximum allowable mass odour emission rates. It is assumed that all odourous air generated within the pumping station operations will be passed through the odour abatement plant and the treated air is exhaust through a vent at roof level. Using dispersion modelling the maximum odour emission rate and the maximum allowable mass odour emission rate (MAOER) were determined for the pumping station to eliminate the risk of any possible odour complaints. Tender specifications for odour abatement on the Pumping station designs will specify a maximum allowable odour emission rate (MAOER). The different distances and directions that the proposed pumping station operations are located from the neighbouring dwellings are represented in Figures to Using three years worth of hourly sequential meteorology data for the operation of the Dispersion Model provided conservative worst case dispersion estimates within the dispersion model. This allowed for the determination of the worst-case meteorological year for the determination of overall odour impact from the proposed Pumping station designs on the surrounding population. Following development of volumetric and odour emission rates, one data set for each pumping station for overall odour emission rate was calculated to determine their potential odour impact during proposed future operation. These included: Scenario 1 Scenario 1 Predicted overall odour emission rate from proposed Carrickarory Pumping station design (see Table in Full Report in Volume 2 - Appendices). Predicted overall odour emission rate from proposed River Row Pumping station design (see Table in Full Report in Volume 2 - Appendices). Scenario 3 Predicted overall odour emission rate from proposed Greencastle Pumping station design (see Table in Full Report in Volume 2 - Appendices). EPA Export :10:54:14

81 Environmental Impact Statement Section 11- Page 8 Scenario 4 Predicted overall odour emission rate from proposed Glenburnie Pumping station design (see Table in Full Report in Volume 2 - Appendices) Scenario 1 Impact - Odour plume dispersal for proposed Pumping station to be located at Carrickarory The plotted odour concentrations of 0.10 Ou E m -3 for the 99.5 th percentile for the proposed Carrickarory Pumping station operation is illustrated in Figure As can be observed, it is predicted that odour plume spread is radial with a diameter of 50 metres. During operations, all residents will perceive an odour concentration of less than 0.10 Ou E m -3 at the 99.5 th percentile during operation of pumping station. This is approximately 93% lower than the odour impact criterion (3.0 Ou E m -3 ). An odour threshold concentration less than 100 Ou E m -3 should be maintained upon the exhaust airstream in order to ensure odour free conditions in the vicinity of the pumping station operation. The odourous processes located within the pumping station should be placed under negative extraction to ensure no fugitive escape of odours Scenario 2 Impact - Odour plume dispersal for proposed Pumping station and Storm tank to be located at River Row, Moville The plotted odour concentrations of 0.30 Ou E m -3 for the 99.5 th percentile for the proposed Moville Pumping station operation is illustrated in Figure As can be observed, it is predicted that odour plume spread is radial with a diameter of 25 metres. During operations, all residents will perceive an odour concentration less than 0.30 Ou E m -3 at the 99.5 th percentile during operation of pumping station. This is approximately 93% lower than the odour impact criterion. An odour threshold concentration of less than 100 Ou E m -3 should be maintained upon the exhaust airstream in order to ensure odour free conditions in the vicinity of the pumping station operation. The odourous processes located within the pumping station should be placed under negative extraction to ensure no fugitive escape of odours. In addition, passive filter capable of treating 0.31 m 3 /s will be fitted to the storm water tank at River Row in order to ensure no emissions of untreated odours from this process. This will minimise the risk of odour impact in the vicinity of the proposed operations Scenario 3 Impact - Odour plume dispersal for proposed Pumping station to be located at Greencastle. The plotted odour concentrations of 0.10 Ou E m -3 for the 99.5 th percentile for the proposed Greencastle Pumping station operation is illustrated in Figure As can be observed, it is predicted that odour plume spread is radial with a diameter of 75 metres. During operations, all residents will perceive an odour concentration less than 0.10 Ou E m -3 at the 99.5 th percentile during operation of pumping station. This is approximately 93% lower than the odour impact criterion. An odour threshold concentration less than 100 Ou E m -3 should be maintained upon the exhaust airstream in order to ensure odour free conditions in the vicinity of the pumping station operation. The odourous processes located within the pumping station EPA Export :10:54:14

82 Environmental Impact Statement Section 11- Page 9 should be placed under negative extraction to ensure no fugitive escape of odours Scenario 4 Impact - Odour plume dispersal for proposed Pumping station to be located at Glenburnie, Co. Donegal The plotted odour concentrations of 0.10 Ou E m -3 for the 99.5 th percentile for the proposed Glenburnie Pumping station operation is illustrated in Figure As can be observed, it is predicted that odour plume spread has an approximate spread diameter of 40 metres. During operations, all residents will perceive an odour concentration less than 0.10 Ou E m -3 at the 99.5 th percentile during operation of pumping station. This is approximately 93% lower than the odour impact criterion. An odour threshold concentration less than 100 Ou E m -3 should be maintained upon the exhaust airstream in order to ensure odour free conditions in the vicinity of the pumping station operation. The odourous processes located within the pumping station should be placed under negative extraction to ensure no fugitive escape of odours Summary A worst-case odour abatement efficiency was modelled using the atmospheric dispersion model with 3 years worth of hourly sequential meteorology data. A worst-case meteorological year and worst-case odour emission data was used to predict any potential odour impact in the vicinity of the proposed Pumping stations. Odour impact potential was discussed for the proposed operation of the Pumping stations with the implementation of considered abatement protocols. It was concluded that: No elevated ambient H 2 S concentrations were detected at the boundary of the currently un-constructed Pumping stations to be located in Carrickarory, Moville, Greencastle and Glenburnie on the day of monitoring with all levels within the recommended WHO guideline value; A distinctive sea and fish odour was noted by the visiting odour consultant at the proposed Pumping station locations in Moville and Greencastle, respectively. A large and varied range of speciated Total Volatile Organic Compound s (TVOC s) were detected in the ambient air at each proposed Pumping station. These are mainly associated with background concentration levels and traffic derived. The highest TVOC was measured in Greencastle which would correspond with high traffic quantities and diesel based emissions from the harbour. The TVOC concentrations were 116, 139 and 225 µg/m 3 at Carrickarory, Moville and Greencastle respectively. During proposed future operation at full capacity, negligible odour impact may be perceived by residents located in the vicinity of the Pumping stations. It is assumed that the currently proposed odour abatement protocols are effective in preventing fugitive odour emissions from the Pumping EPA Export :10:54:14

83 Environmental Impact Statement Section 11- Page 10 station processes. Wet well covers are assumed to be near 100% sealed. The headspace of the wet and dry wells will be exhausted through an odour control system to abate any odours. The treated air from Carrickarory, Moville, Greencastle and Glenburnie Pumping stations should not exceed an odour threshold concentration of 100 Ou E m -3. The odour emission rate from the proposed Carrickarory Pumping station should not exceed a total treated exhaust odour emission rate of 3 Ou E /s assuming a total wet well volume of 0.36 m 3 assuming 20 AC/hr. The odour emission rate from the proposed Moville Pumping station should not exceed a total treated exhaust odour emission rate of 39 Ou E /s assuming a total wet well volume of approximately 28 m 3 assuming 10 AC/hr and assuming a total liquid influent flow of m 3 /s to the storm water tank. The stormwater tank will be fitted with a passive odour control unit capable of treating 0.31 m 3 /s of positively displaced air from the sealed storm water tanks during operation. The odour emission rate from the proposed Greencastle Pumping station should not exceed a total treated exhaust odour emission rate of 2 Ou E /s assuming a total wet well volume of approximately 6 m 3 assuming 10 AC/hr. The odour emission rate from the proposed Glenburnie Pumping station should not exceed a total treated exhaust odour emission rate of <1 Ou E /s assuming a total wet well volume of approximately 0.4 m 3 assuming 10 AC/hr. The proposed Pumping stations to be located in Carrickarory, Moville, Greencastle and Glenburnie should not cause any odour impact with all pumping stations contributing an odour concentration less than 0.10 Ou E m -3 to background odour concentrations at the 99.5 th percentile of worst case meteorological conditions Mitigation Measures Pumping Stations The following mitigation measures are proposed: The pumping station wet wells and storm water tank at River row should be sealed using tight fitting covers to ensure no uncontrolled fugitive odour emissions. During proposed operation with odour abatement techniques installed, the odour concentration will be less than 0.30 Ou E m -3 at the th percentile for a worst case meteorological year. Install odour control units at the four pumping stations and ensure a passive filter capable of treating 0.31 m 3 /s is fitted to the sealed storm water tank to be located in River Row. EPA Export :10:54:14

84 Environmental Impact Statement Section 11- Page 11 Maintain good housekeeping practices within and in the vicinity of the pumping stations. Avoid accumulation of debris and persistent sediments in the vicinity and within the pumping station process room. Ensure an odour management maintenance plan is implemented for the operation of the pumping stations to be located in Carrickarory, Moville, Greencastle and Glenburnie. Donegal County Council will ensure that the recommended mitigation measures are implemented. EPA Export :10:54:14

85 Environmental Impact Statement Section 11- Page 12 Odour Assessment Summary Table Potential Impacts Mitigation Measures Residual Impacts WWTP Potential for odour impact from the WWTP. The proposed WWTP should not exceed the odour emission rate of Ou E s -1. All odour sources located within the inlet works and sludge handling processes should be abated in order to prevent the emissions of hedonically offensive odours. This will ensure that odour concentrations will not exceed the recommended level of 3ouE m- 3 at the nearest odour sensitive location. With mitigation measures are implemented no significant odour impact should be perceived by residents in the vicinity of the proposed WWTP Pumping Stations Potential for odorous compound formation in the Pumping Stations. Additional odour abatement protocols are detailed in section and in section of the full report (Volume 2 Appendices) The provision of the odour abatement protocols and the proper operation and maintenance of the WWTP will ensure compliance with the European Communities (Waste Water Treatment) (Prevention of Odours and Noise) Regulations 2005 (S.I. No. 787 of 2005). During proposed operation with odour abatement techniques installed, the odour concentration will be less than 0.30 Ou E m -3 at the th percentile for a worst case meteorological year. Additional odour abatement protocols are detailed in section and in section of the full report (Volume 2 Appendices) With mitigation measures are implemented no significant odour impact should be perceived by residents in the vicinity of the proposed pumping stations. The predicted ground level odour concentration is approximately 10 times less than the limit value used to determine odour impact. EPA Export :10:54:14

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