------..

Kerry West Villages Sewerage Schemes - T.J. O'Connor &Associates • October 2007 Village Number of Tourist beds

Brandon 29 Boolteens 18 Castlegregory 70 Aughacasla No registered accommodation Castlemaine 28 Inch/ 117 No registered accommodation

Table 2.5 List of Registered tourist beds currently available in each town and village (from Tourist Office)

Tourism in Kerry is predominantly based on a clean, unspoilt natural environment of which waterways, including the bays of Dingle, and Brandon, are a major part. It is envisaged that the sewerage scheme for Castlegregory can playa significant role in protecting this natural environment by maintaining or improving water quality in the receiving waters.

2.8 Climate and Rainfall Data

Rainfall data for the town of Castlegregory was obtained from Met Eireann. The average annual rainfall for the Castlegregory area is some 1,200mm reflecting the exposed Atlantic location.

The one in five year rainfall of 60 minute duration is reported by Met Eireann to be 16.0mm in Castlegregory. The Forcorresponding inspection purposes only.one in five year rainfall of 48 hour duration Consent of copyright owner required for any other use. (M5 48hour) is 80mm. The rainfall figures are detailed in Appendix 2.

The M5 (2day) can be calculated from the M5 (48h) since the relationship between the two is: M5 (48h) = 1.06 M5 (2d)

Therefore the M5 (2d) for Castlegregory =75.5mm. The M5 (2d) refers to an expected rainfall with a return period of 5 years over 2 calendar days, whereas the M5 (48h) refers to rainfall with a return period of 5 years over an arbitrary period of 48 hours.

The prevailing wind directions for Valentia Observatory are detailed on Figure 2.9 below.

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!":"LM~C

fI :.. 10 n 20 25~ L...-L.1 .1 I" Scalt'ofSpC('d o.\·~~" 31?3uforl ~ oree '~,.3

For inspection purposes only. Consent of copyright owner required for any other use. Figure 2.9 Frequency of wind directions for groups of Wind speeds at selected stations (1962 -1984)

2.9 Existing Wastewater Loads

2.9.1 Flow and Load Survey

A survey of the existing flows and wastewater pollutant loads arising in Castlegregory was undertaken as part of this preliminary report. The survey comprised flow monitoring at two points on the collection system and at a point on the final effluent outfall. Samples of the influent to the VVWTP and of the receiving waters were also taken and analysed. The survey was undertaken b~ Capital Water Systems over a three week period between the 19th April 2006 and the 10 May 2006. The full results of the survey are reproduced in a report from Capital Water Systems contained in Appendix 9 and are summarised briefly below.

Three flow monitors were installed of which two were installed on the collection system whilst the third was installed on the final effluent outfall pipe. A single tipping bucket rainfall gauge was installed on the roof of the septic tank at the VVWTP.

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Flow monitor No. 3 was installed on a 300mm diameter pipe at the junction between Forge Street and Strand Lane. This sewer would carry flow from approximately half of the contributing Population of the town including Strand Street and Forge Street but excluding flows from Tailor's Row, College Street and Main Street. The monitor was installed on an outgoing pipe from a manhole and although the report suggests that the quality of the data returned was good, there would be a concern that the velocity and flow data would not be as accurate as if the monitor was installed on an incoming pipe to a manhole. The survey recorded surcharging on this pipe during a rainfall event on May 4th to a depth of more than 200mm. The rainfall event which gave rise to surcharging comprised some 15mm of rainfall over a 2.5 hour period. This would confirm that a significant quantity of stormwater enters the system upstream and suggests that the system may be prone to more serious surcharging or flooding from rainfall events with a higher return period. As the ground profile in the area falls steeply away toward the WWTP, any such flooding might not impact on local properties.

FLOW (lis) Total vol = 254.1 m3 Peak = 64.3 80 [03)

40

o 2 4 6 8 SITE 03: 3-MAY-06 2:00 to 3-MAY-06 8:00 (Time in hours)

DEPTH (mm) Pipe height = 300 mm Peak =508.0 600 [03] 400 PIPE HT

200 For inspection purposes only. Consent of copyright owner required for any other use.

o 246 8 SITE 03: 3-MAY-06 2:00 to 3-MAY-06 8:00 (Time in hours)

Figure 2.10 • Extract from Flow and Load Report for Castlegregory showing surcharging of the 300mm diameter sewer at bottom of Forge Street.

Night-time dry weather flows at this site were below the resolution of the instrumentation with zero readings being recorded. The system upstream of this monitor would not therefore appear to be especially prone to infiltration.

The second flow monitor installed was on the 375mm diameter inlet sewer to the WWTP. It would thus include all of the flows arising in the town. Surcharging of this pipe occurred in response to rainfall on three occasions during the survey. The surcharging in each case rose to around 175mm above the soffit of the pipe. As the flow rates in the pipe were well below the nominal (pipe-fUll) capacity of the pipe, the surcharging must have occurred in response to downstream conditions. This suggests that the overflow arrangement at the WWTP influences depths of flow in this part of the collection system.

Depths of flow at night-time generally fell below 50mm and the instrumentation would not be expected to provide accurate readings in these circumstances. An inspection of the

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flow trace on dry weather days shows no discernible diurnal pattern. The results returned in respect of total daily flows are therefore of questionable accuracy.

The third monitor was installed on the outfall pipe from the WWTP. The pipe invert level at this site is within the normal tidal range and the high tide is clearly visible on the depth traces for dry weather days. Flow in this pipe is generally sluggish with typical velocities of around 0.2 m/s. This rises to around 0.9 mls in storm conditions.

Other works undertaken as part of the flow and load survey included sampling and analysis of the influent to the WWTP and of the receiving water, both upstream and downstream of the existing final effluent outfall. The results from these analyses are discussed in later sections of this report.

For inspection purposes only. Consent of copyright owner required for any other use.

Figure 2.11 Existing Septic Tank at Castlegregory WWTP

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2.9.2 Estimated existing WWTP Load

As part of the flow and load survey referred to above, the concentrations of influent BOD, COD, suspended solids and pH were measured on the inlet to the WNTP. These measurements are reproduced in full in the report from Capital Water Systems Limited. This showed the BOD to be in the range 623 mg/l to around 100 mg/I on dry weather days. As described above, the measurement of flows on the inlet sewer in dry weather conditions are not considered to have an acceptable accuracy because of an inadequate depth of flow. It is therefore not possible to use these in conjunction with the influent BOD concentrations to assess the total load to the plant.

In the absence of such measurements, it is possible to estimate the load to the WNTP from the population of the town and the associated non-domestic loads. In the following calculations of existing and projected effluent volumes, the unit rates shown in Table 2.6 have been adopted (Figures taken from "A review of current Water Design Standards for Water Supply Schemes" April 1983):

Wastewater flow Estimate of flow rates rates Domestic 0.225m3 /hd/day Industry - Light 28 m3/ha/day Institutional - schools 0.045m 3 /hd/day Restaurant 0.0675 m3/seat

Table 2.6 Wastewater Flow Rates

The population equivalent loading for garages, offices, shops, post offices, and similar premises is assumed to be similar to domestic loading (i.e. 3PE.) and the wastewater flow rates can then be calculated from the loading. For inspection purposes only. Consent of copyright owner required for any other use. Effluent characteristics assumed for domestic, commercial and institutional effluents are as follows:

COD 150 g/hd/day 8005 60 g/hd/day (240 mg/l) SS 75 g/hd/day (300 mg/l) NKJ 11 .4 g/hd/day p 3.0 g/hd/day

Table 2.7 Typical Effluent Characteristics

Table 2.8 below outlines the existing wastewater loads and population equivalents for the town. Further details on the population projections for Castlegregory are detailed in Appendix 1. The future population projections and waste water loadings (for Phase 1) are detailed in Section 3 and Appendix 1.

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~' "' No of No. of Area Estimated Wastewater Type of user units persons (ha) flow rate** load (m3/day) P.E. Domestic Existing from house count 164 469 0.225m3/hd/day 78.5 469 Planning Approvals recently completed or under construction 7 20 0.225m3/hd/dav 4.50 20 -1 Non-Domestic .. ~ " Church 1 0.0427 5m 3/ha/day 0.2135 1 Community Centre 1 0.0312 0.225m3/hd/day 0.675 3 120 + Schools 2 150 0.045m3/hd/dav 12.15 54 Shops 7 0.1317 0.225m3/hd/day 4.725 21 Pubs 9 30.38 135 Post office 1 0.011 0.225m3/hd/day 0.675 3 Restaurants/Cafes 2 30** 0.0675 m3/seat 2.025 9 Garages 2 0.225m3/hd/day 1.35 6 Fire Station 1 0.0093 0.225m3/hd/dav 0.675 3 Garda Station 1 0.0109 0.225m3/hd/day 0.675 3 Furniture Hall 1 0.0329 0.225m3/hd/day 0.675 3 All types 70 70 0.225m3/hd/dav 15.75 70 r Total Population Equivalent ~ 800 Total Wastewater Load ~ 180 ,,- + No. of pupils ** Assumed number of seats Table 2.8 For inspection purposes only. ExistingConsentWastewater of copyright ownerloading requiredand for anyPopulation other use. Equivalent estimates

As outlined in Table 2.8 there are no large wet industries in Castlegregory. The wastewater can be assumed to comprise mainly domestic sewage, with COD, BODs, suspended solids, nitrogen and phosphorus loadings as defined in Table 2.7. By applying each of these values to the existing PE figures from Table 2.8 the breakdown of existing wastewater loadings to the existing WWTP are calculated. The existing wastewater loadings to the existing WWTP are detailed in Table 2.9.

Volumes P.E. COD BODs 5.5 Nkj P (m 3/day) Kg/day Kg/day Kg/day Kg/day Kg/day 180 800 120 48 60 9.12 2.4

Table 2.9 Breakdown of existing wastewater loading for Castlegregory

2.10 Existing Water Supply Infrastructure

The existing public water supply for Castlegregory is provided by Kerry County Council and is taken from an abstraction on Stradbally Mountain.The layout of the existing water supply network is detailed on Drawing Number 2596-CG-02.

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2.11 Existing Wastewater Infrastructure

2.11.1 Wastewater Collection System As previously noted, Castlegregory already has a wastewater collection system and Wastewater Treatment Plant (WWTP). The extent of the existing network is shown on drawing 2596-CG-03. The system comprises mainly 150mm and 225mm diameter sewers which run along/under the main streets of the town. A 375mm diameter inlet sewer conveys the total flow from the town to the existing WWTP. The existing sewer network is mainly combined so that surface water runoff from road and houses in the town also drains to the WWTP.

A CCTV camera survey of the existing sewerage systems at Castlegregory was undertaken by Messrs. USA Ltd of Dublin following advertisement and tendering. The survey was undertaken during March and April of 2006. The reports submitted following the survey included the video footage of each of the 2.2km of sewers that were surveyed and a detailed structural and serviceability assessment in accordance with the WRC Sewerage Rehabilitation Manual (SRM). This involves assigning a Structural • Performance Grade (SPG) to each length of sewer that was surveyed. The structural gradings range from grade 5 (collapsed or imminent state of collapse) to grade 1 (as new) with intermediate grades reflecting varying degrees of structural deterioration. In accordance with the SRM all sewers with Structural Performance Grades (SPGs) of 4 or 5 are deemed to be in need of immediate attention and should be rehabilitated or replaced. Lesser grading may merit immediate repair depending on their 'criticality' to the operation of the sewer network.

For inspection purposes only. Consent of copyright owner required for any other use.

Figure 2.10 View along Taylor's Row, Castlegregory

For the Castlegregory scheme, the survey showed the system to be in a moderate state of repair with comparatively short lengths of SPG 4 and SPG5 being recorded but

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Castlegregory T.J. O'Connor & Associates • October 2007 significant lengths of SPG 3 were recorded. The SPG 4 and 5 defects were generally associated with badly constructed saddle connections and severe longitudinal factures leading to deformation of the pipe (ovality). Extensive cracking of the sewers on Strand Road, Kilshannig Road, Forge Road and Tailor's Row was noted. These defects generally merit an SPG 3 classification. As many of these sewers are 150mm in diameter and are proposed to be replaced by 225mm diameter sewers (see Section 4.00), the structural problems with these pipes is being addressed indirectly by their replacement. Sections of the 150mm pipe work is in good condition and can be retained as rider sewers or as connections from some properties.

Serviceability grades were also assigned to the sewers that were surveyed. These serviceability grades reflect the ability of the pipe to serve its intended purpose (i.e. the passage of flow up to the full capacity) excluding structural deterioration. Obstructions, debris, grease, infiltration, encrustation, and root intrusions are among the common problems meriting a high serviceability grade. As much of the sewer network had to be cleaned before camera access was possible, the serviceability grades recorded would reflect the removal of most of the existing obstructions in the sewers. Prior to sewer cleaning some 20 survey attempts had to be abandoned mainly due to debris and • intruding lateral connections which prevented the passage of the camera along the pipe.

A summary of the various structural and serviceability grades assigned to pipes of 225mm diameter and above is presented in Appendix 10.

2.12 Private Wastewater Treatment

A check was carried out on planning applications submitted to Kerry County Council in recent years with regard to the installation of private package wastewater treatment plants. Planning permissions granted in 2004 included two housing developments in Castlegregory where private wastewater treatment plants were proposed. These comprise of a 37 house development at Cahir Place situated between Strand Road and the existing public WWTP and the other a 45 house and commercial premises located in Martramane on the southern outskirts of the town. It was proposed that the development For inspection purposes only. on Strand Road wouldConsentinstall of copyrighta Klargester owner required Biofor anydisc other use.sewage treatment unit and the development at Martramane would install an EPS Bison treatment system prior to their discharge to the public network. Both of these developments are now SUbstantially completed. • 2.13 Existing Surface Water Infrastructure

The main drainage system for the town is fully combined so that runoff from roads, roofs and paved areas as well as foul sewage is drained to the collection system and is conveyed to the WWTP. There are therefore no (separate) surface water sewers in the main part of the town.

All recent planning approvals have required separate surface water and foul sewers to be installed as part of new developments. There are accordingly some comparatively new stormwater drainage systems that have been/will be taken in charge by the council. This would include the Caher Square development north of the town.

2.14 Recommended Storm Water Management Policy

In the last fifteen years or so it has been realised that urban stormwater drainage systems have a finite capacity and that uncontrolled discharges from new developments to existing drainage systems or directly to watercourses can give rise to or exacerbate

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flooding problems and/or have an adverse impact on the ecology of the receiving waterbodies. The concept of stormwater management and sustainable urban drainage have been conceived as a response to these problems and are increasingly being applied by planning and drainage authorities as a means of avoiding the problems described above. The aim of these systems is to mimic (insofar as possible) the natural environment with runoff being infiltrated to groundwater where possible/appropriate or being stored and slowly released to watercourses at rates which would be comparable to that which would occur from the same area were it undeveloped. Guidelines for the development of these types of systems have been in place since the mid 1990s with Scotland in particular leading the way. In Ireland, Dublin Corporation published The Dublin Stormwater Management Policy in 1998 in response to these concerns. Similarly, CIRIA published the document "Sustainable Urban Drainage Systems - Design Manual for Scotland and Northern Ireland" in 2000. Both these documents address the issues associated with development of land without causing flooding. The CIRIA document has a broader scope in that it also addresses issues of water quality. Many local authorities in Ireland already have stormwater management guidelines in place, particularly those incorporating the larger towns and cities. The control of stormwater discharges to watercourses is obviously of greater importance where the potential scale of urbanisation is significant in relation to the size and character of the receiving water. The main thrust of existing guidelines is the limitation of run-off from newly developed areas via infiltration to groundwater and/or on-site storage. Methods to calculate the acceptable rate of discharge from new developments are proposed and recommendations made regarding the most appropriate solutions for the particular circumstances prevailing. These systems would include swales, attenuation ponds, soakaways, underground storage and above ground containment of water in extreme/high return period events. In the case of Castlegregory, there are several watercourses in the area which could serve as convenient points of discharge for new surface water drainage systems. These watercourses include the Killiney Stream, , and the (unnamed) stream on the eastern outskirts of the town. None of these watercourses are known to have associated flooding problems. In these circumstances it is suggested that there would not be a particular need Forfor inspectiona stormwater purposes only. management policy for Castlegregory as Consent of copyright owner required for any other use. the areas involved are relatively small and the watercourses themselves lie mainly outside the urban areas. Where very large scale housing developments are proposed, these can be assessed on a case by case basis and planning conditions can be used to deal with any requirements for local on-site attenuation measures for such developments • to control the rate of runoff to the streams where this is found necessary.

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3.0 Proposed Project

3.1 Context

As part of the Wastewater and Sludge Project, it is Kerry County Council's intention to address the procurement, management and operation of new and upgraded wastewater infrastructure in 90 towns and villages in County Kerry. These towns and villages were identified in the County Development Plan 2003-2009 and were grouped into a settlement hierarchy of 5 categories as follows:

• 3 Regional Centres • 7 District Centres • 7 Towns • 28 Small Villages • 45 Small Villages/Development Nodes

The Advance Study aspect of the County Kerry Wastewater and Sludge Project is the • preparation of 28 Preliminary Reports for specified towns and villages in the County as follows:

• Brief 1 North Kerry • Brief 2 Mid Kerry • Brief 3 West Kerry • Brief 4 South Kerry

T.J. 0' Connor and Associates were commissioned to undertake Brief 3 (West Kerry) which consists of preparing Preliminary Reports for the towns and villages of Castlegregory, Annascaul, Castlemaine, Boolteens, Aughacasla, Brandon and Cromane. The brief also included the preparation of Development Boundary Maps for each settlement.

For inspection purposes only. 3.2 Design PopulationConsent of copyright owner required for any other use.

The final population figure for Castlegregory is taken as 2,250 persons with the Phase 1 population taken as 1,500. With the inclusion of pumped flows from the village of Aughacashla as proposed, the final design loads for the WWTP are 2,358 PE (858PE • from Aughacashla) for Phase I and an ultimate load of 3,258 PE (1008PE from Aug hacashla).

The Population Equivalent (PE) shown below in Table 3.1 below is based on a house count of the existing dwellings, and on an assessment of the non-domestic (commercial/institutional) loads in the town. The tourist loading was also taken into account as detailed in Section 2.7. For the purposes of the design of the scheme for this Preliminary Report the Phase 1 population for Castlegregory of 1,500 is used .

~~. ~l Type of user '.J} • ,~ No of units No. of persons P.E. "~,,5 ':: Domestic ~ Existing 164 469 469 Under constructionl infill area in village (from planning search) 95 272 272 ., r.. Non-Domestic

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Castlegregory T.J. O'Connor &Associates • October 2007 Church 1 1 Community Centre 1 3 Schools 2 120 + 150 54 Shops 7 21 Pubs 9 135 Post office 1 3 Restaurants/Cafes 2 30 9 Garaqes 2 6 Fire Station 1 3 Garda Station 1 3 Furniture Hall 1 3 Holiday Accommodation 70 70 70 Total Existing non-domestic 311 Allowances for future development to Phase I J Domestic 360 Non-domestic 88 Total Population Equivalent -'co .' ~ m "r., 1,500

Table 3.1 Design population for Castlegregory

The figures in respect of under construction/infill areas include recently completed developments within the Phase 1 boundary which are served by private wastewater treatment systems. The estimates above assume that these private treatment systems will ultimately be abandoned in favour of a connection to the Castlegregory main drainage scheme with the wastewater being conveyed onward to the proposed \MNTP.

3.3 Design Wastewater Loads

For inspection purposes only. As described in the preliminaryConsent of copyrightreport ownerfor requiredAughacasla, for any otherpumping use. of sewage flows arising in

the village onward to Castlegregory is proposed. This solution was found to be more economic than treatment of the flows locally in Aughacasla. The Aughacasla preliminary report identifies a Phase I loading of 858 PE (includes 608PE for caravan parks) and an ultimate (Phase 2) load of 1,008 PE. The final plant loadings for the Castlegregory WWTW have been revised as below to take account of the flows and loads which are to be pumped to Castlegregory. The associated BOD, suspended solids, Nitrogen and Phosphorus plant loadings are as shown in Table 3.2 below.

Design Design COD BODs 5.5 Nkj P volumes P.E. Kg/day Kg/day Kg/day Kg/day Kg/day (m 3/dav) 1,591.7 2,358 353.7 141.5 176.9 26.9 7.07 (3DWF)

Table 3.2 Breakdown of proposed (Phase I) loading for Castlegregory WWTP

3.4 Scheme Boundary The boundary for the scheme is dictated by the development boundary shown on Drawing 2596-CG-01. The area of the Phase 1 (pink & yellow) boundary is 50.9 hectares with the Phase 2 (blue) boundary being 47hectares.

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Cast/egregory T.J. O'Connor &Associates • October 2007 3.5 Phasing Phase 1 of the proposed development will involve the construction of pipelines which will serve the catchment area for Phase 1 as detailed on Drawing 2596-CG-01. The existing combined sewer network will be retained as a foul sewer network and will be remediated, upsized and extended as necessary to serve the proposed Phase 1 catchment area. It is further proposed that a surface water sewer network will be constructed to serve the areas highlighted on Drawing Number 2596-CG-05. Surface water outfalls from the remainder of the Phase 1 catchment will drain directly to the existing watercourses. Design of surface water networks for these areas will be development led. The proposed Phase 1 pipeline works are detailed on Drawing 2596-CG-06 and Drawing CG-2596-CG­ 07. Phase 1 of the proposed development will also include the construction of a WWTP at a new site to serve a population equivalent of 2,358PE. The level of wastewater treatment required is detailed later in this report.

In order to cater for the foul sewage and surface water flows from Phase 2 the proposed pipeline networks will be extended as detailed on Drawing 2596-CG-06 and Drawing CG­ 2596-CG-07. The Phase 2 works will require the construction of pumping stations at the • locations detailed on Drawing Number 2596-CG-07.Phase 2 works will also involve the extension of the proposed WWTP to cater for a design population of 3,258PE.

3.6 Archaeological Features In common with much of the rest of the , Castlegregory is thought to be rich in archaeology stemming from a history which pre-dates the arrival of Christianity. The main archaeological features in the town are the site of a ruined castle at the rear of Tailor's Rowand a holy well at Toberagow (see Figure 3.1) on the . The castle, which was built by Gregory Hoare in the 16th century was destroyed during the Cromwellian Wars of 1649. However important fragments from the castle have survived including intricately carved stonework some of which may still be seen in the town. The proposed sewers do not encroach the site of the castle however new sewers are proposed along Tailor's Row which is adjacent to the site of the castle. The publication "Archaeological Survey Dingle Peninsula" lists 2 other archaeological features in For inspection purposes only. Castlegregory, one beingConsenta ofsouterrain copyright owner closerequired forto anythe otherbeach use. and the second a kitchen midden whose precise location is unknown but is thought to be the source of the stone pendant which was recovered in 1939.

Excavations for new sewers throughout the town would have the potential to unearth • previously undocumented archaeology and attendance by registered archaeologists during excavations may be necessary. This may also apply to topsoil stripping at the site of the proposed WWTW although this is reclaimed/improved marshland which would not have been suitable for permanent habitation.

An archaeological impact statement on the proposed Castlegregory Sewerage Scheme will be undertaken at detailed design stage. The desk study will identify areas of archaeological potential and known archaeological sites and monuments in the study area.

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Figure 3.1 Gated access to well at Toberagow off the Dingle Way

For inspection purposes only. Consent of copyright owner required for any other use.

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Cast/egregory T.J. O'Connor &Associates • October 2007 3.7 Wastewater Treatment Plant Site Location

It is proposed to construct the proposed WWTP on a new site further east of the existing IJINJTP. The existing site cannot accommodate the plant and equipment required to treat the design loads to the standards identified. It also has particularly poor access arrangements with tractors required to collect and tanker sludges off site. The newly constructed secondary school has been built on the adjoining site to the south west and new housing has been constructed to the site boundary to the north east.

As the eXisting collection system drains toward this part of Castlegregory, the new site for the WWTP would logically be located within the same general area. This would also allow the existing final effluent outfall pipe and discharge to be used. However the most significant problem associated with the area is access from the public road and the generally poor marshy ground conditions. The site chosen, and shown on drawings 2596­ CG-15, has potential access off the Dingle Way with good visibility afforded at the junction as required under general planning guidelines. The existing access can be retained and extended to the new site boundary as an emergency/secondary access route as sections of the Dingle Way are low in level and can be prone to flooding at extremely high tide conditions. Some additional expenditure on foundation support systems will be required to overcome the (expected) poor ground. However this would not be offset by the cost of acquiring a site further inland and transferring and returning the flow to such a site.

For inspection purposes only. Consent of copyright owner required for any other use.

Figure 3.2 View along the Dingle Way taken from the Main Street Castlegregory looking south East

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4.0 Proposed Network

4.1 General

The existing combined system will be retained as a foul sewerage collection system and will be upsized, remediated and extended as necessary. It is proposed that a new surface water collection system will be constructed to serve the town centre area of Castlegregory and its environs.

The foul sewerage collection system has been designed based on a dry weather flow (DWF) of 225litres/population equivalent (PE) / day. This takes account of diurnal peaks, the daily and seasonal fluctuations in water consumption and an allowance for extraneous flows such as infiltration. Pipelines have been designed to cater for 6*DWF. For the design population equivalent of 2250pe the maximum design flow is 0.035m3/s. A 225mm pipeline laid at a gradient of 1 in 200 with a pipe roughness (k) value of 0.6mm has a design flow of 0.037m3/s The proposed surface water drainage network was designed using the WINDES Micro Drainage Design software which is based on the Wallingford Procedure. The pipe network has been sized using a standard rainfall intensity of 50mm/hour for a 1 in 2 year return event. The contributing area to the network has been taken at 30% of the catchments area for lands within the existing developed envelope of the town and 10% of the catchments area for lands outside the existing town boundary. The contributing area to the network design is significantly less than the overall area to allow for the application of sustainable urban drainage systems (SUDS) policy whereby outfalls from proposed development are limited to that from the greenfield/ brownfield site, before the development takes place. Surface water design calculations are included in Appendix 4.

4.2 Proposed Foul Network

The layout of the proposed Forfoul inspectionsewerage purposes only.collection system is indicated on Drawing Consent of copyright owner required for any other use. Numbers 2596-CG-07. Phase 1 pipeline sections are shown on Drawing Numbers CG­ 2596-08 and CG-2596-09. Phase 2 pipelines are shown on Drawing Numbers CG-2596­ 10 and CG-2596-11 .

It is proposed that the existing combined sewerage collection system be retained as a • foul sewerage collection system. It is further proposed that a minimum pipe diameter of 225mm be adopted in order to minimise blockages, which can be caused by extraneous objects dropped into smaller diameter sewers. Therefore all existing sewers to be retained whose diameters are less than 225mm diameter will be upsized to 225mm diameter. Some of the existing 225mm and 300mm diameter sewers will require some form of remediation. The sewers requiring remediation are identified on Drawing Numbers CG-2596-04. The existing collection system will be extended where necessary to the development boundary to enable all foul sewage outfalls from within the Phase 1 development boundary to discharge to the proposed foul sewerage collection system. A proposed rising main from the pumping station in Aughacashla will discharge foul sewage flows from Aughacasla to the Castlegregory Sewerage Scheme. Manhole PF41 as shown on Drawing 2596-CG-07 could serve as the discharge point for the rising main from Aughacashla. Alternatively flows from Aughacashla could be pumped directly to the proposed Castlegregory WWTP. An ultimate flow of 15.85 I/s from Aughacashla corresponding to 6 x DWF at the Phase II (1008 PE) load, is to be conveyed onward to theWWTP.

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4.3 Proposed Storm Network

The layout of the proposed surface water sewerage collection system is indicated on Drawing Numbers 2596-CG-06. Pipeline sections are shown on Drawing Numbers CG­ 2596-12, CG-2596-13 and CG-2596-14

Surface water outfalls from Castlegregory will be collected in three separate surface water collection systems and discharged via three separate outfalls to existing watercourses. The catchment area of each of the networks and the catchment area of each individual pipeline are outlined on Drawing Number 2596-CG-05.

The surface water sewerage collection system has been designed to cater for all lands within the proposed Phase 1 development boundary with the exception of lands to the north east and north west of the catchment. It is not feasible to include these lands in the proposed collection system due to the topography of the catchment. These lands to the north west of the catchment can be included in a storm water collection system for Phase 2 which would drain to Lough Gill. The lands to the north east will drain to an existing watercourse to the east. It is envisaged that the design of a surface water collection system for these parcels of lands will be development led.

For inspection purposes only. Consent of copyright owner required for any other use.

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5.0 Proposed Treatment

5.1 General

The standard of treatment provided for the proposed VWVTP at Castlegregory must have regard to relevant legislation concerning urban wastewater treatment generally and to have particular regard to the requirements for a discharge to Tralee Bay. The following describes the main factors influencing the choice of wastewater treatment system for Castlegregory having regard to the above and the wastewater loads identified in section 3.0.

5.2 Wastewater Treatment Load

Based on the population projections included in Sections 2.4 and 3.2 of this report, the proposed design population equivalents and loadings for the proposed treatment works are tabulated below in Table 5.1

Design COD BODs 5.5 Nkj P P.E. Kg/day Kg/day Kg/day Kg/day Kg/day 2,358* 353.7 141.5 176.9 26.9 7.07

Table 5.1 Design PE and Wastewater load for Treatment Works

*This figure is the Phase 1 population for Castlegregory and Aughacasla which is to be catered for in the design of the wastewater treatment plant. The plant is to be capable of expansion to the ultimate load of 3,258 PE.

5.3 Discharge Standards

For inspection purposes only. There are a number ofConsentregulations of copyrightgoverning owner required forthe anyrequired other use. standards of treated effluent from wastewater treatment works including the Urban Wastewater Treatment Regulations, 2001 (S.1. No. 254 of 2001) and Local Government (Water Pollution) Act, 1977 (Water Quality Standards for Phosphorus) Regulations, 1998 (S.1. No. 258 of 1998). The Urban Wastewater Treatment Regulations, 2001 sets out specific requirements for • treated effluent quality from treatment works serving a population equivalent (PE) of 2,000 or more. For urban wastewater from agglomerations of less than 2,000 PE. The regulations require that "appropriate treatment" be provided by 31 December 2005. The term 'appropriate treatment' in the regulations implies treatment to a standard that allows the receiving water to meet any relevant water quality standards from other regulations. Relevant regulations in this context would include those made in connection with the EU bathing water directive, the shell fish directive, salmonid water directive and others. For the particular case of the Castlegregory and Tralee Bay, the bathing water regulations, the shell fish regulations, the general amenity use of Tralee bay and its assimilative capacity would be important parameters. The relevance of each of the above to the wastewater treatment standards at the Castlegregory WWTW is described separately below.

5.3.1 Urban Wastewater Treatment Regulations

Although it is not an requirement of the Urban Wastewater Treatment Regulations, treatment of the wastewater to a least a secondary standard in accordance with the Second Schedule, Part 1 of the regulations is normally provided for all local authority

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wastewater treatment plants in Ireland. This provides for a minimum of a 25 mg/l BOD and 35 mg/l Suspended Solids. Phosphorus removal is not required under the urban wastewater treatment regulations as Tralee Bay is not sensitive water and the proposed Castlegregory WWTW is well below the mandatory threshold of 10,000 PE. However the proposed standards of treatment have been further refined to take account of other relevant regulations and of the assimilative capacity of the receiving water.

5.3.2 Phosphorus Regulations

The Phosphorus Regulations (S.1. No. 258 of 1998) sets target standards for phosphorus levels in rivers and lakes which are to be achieved by local authorities over a ten year period which began in 1997. The regulations concern levels of Molybdate Reactive Phosphate (MRP) in freshwater with different classifications of water quality determined from bands of varying concentration expressed as the median annual MRP level. The regulations require local authorities to maintain existing water quality classifications and to bring unsatisfactory (polluted) waters into a satisfactory category by no later than 31 December 2007. Baseline water quality classifications have been assigned to each major river and lake in the country by the Environmental Protection Agency based on results from sampling and analysis undertaken in the years 1995 to 1997. Table 5.2 below shows the classification system for rivers taken from the third schedule of regulations (S.1. No. 258 of 1998).

Existing Biological Minimum Target Molybdate Reactive Quality (Q) ratinglQ Biological Quality (Q) Phosphate Median I Index RatinwQ index Concentration (j.Lg/1) Unpolluted 5 15 5 4 - 5 4-5 20 4 4 30 Slightly Polluted 4 50 3 - 4 For inspection purposes only. Moderately PollutedConsent of copyright owner required for any other use. 3-4 50 3 2 - 3 3 70 Seriously Polluted 3 70 ::;2

Table 5.2 Quality Standards for Rivers from the 3rd schedule of the Phosphorus Regulations

The stream proposed for the discharge of treated effluent from the Castlegregory WWTP is tidal and does not form part of the monitoring required under the phosphorus regulations. Kerry County Council would not appear to have any specific responsibilities in terms of phosphorus removal in connection with this stream. It is additionally noted that the outfall to the stream is a short distance from the confluence with Tralee Bay and that it would not normally be viewed as necessary to remove phosphorus from the effluent in these circumstances as in reality MRP levels would be much further diluted by the tidal flows than the fluvial flows identified in Appendix 8. There is accordingly no requirement or proposal to remove P from the effluent from the proposed WWTP

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Cast/egregory T.J. O'Connor &Associates • October 2007 5.3.3 Waste Assimilative Capacity of Receiving Waters

For the purposes of estimating the required effluent discharge standards, flows in the receiving waters are of particular importance. These are used to assess the available dilution, and the predicted concentration of pollutants in the fUlly mixed receiving water/final effluent combination downstream of the outfall when combined with background water quality measurements. This provides an accepted basis for determining treated effluent discharge standards appropriate to the particular location. In the case of Castlegregory, the proposed final effluent outfall will discharge to a tidal section of an unnamed small stream. This stream rises in Stradbally Mountain and has a catchment area of some 4.5 km 2 to its confluence at Tralee Bay. As the flow in the stream is tidal at the wwtp outfall, a greater flow of water would generally be available for the dilution of the final effluent than would be the case for an exclusively freshwater stream having the same catchment area. The stream was analysed to determine the ninety fifth percentile (freshwater) flow to assess the minimum levels of dilution available. The analysis was based on the Hydra software package. This was developed by the European Small Hydropower Association (Hydra) for use throughout Ireland to provide estimates of low flows in rivers and streams for small-scale hydropower projects. The • package was developed by the Institute of Hydrology in the UK under a European Union funded contract.

The Hydra results for the stream at the proposed point of discharge of the treated effluent shows a 95 percentile flow of 121/s. Further details on the Hydra analysis are given in Appendix 8.

Water quality sampling upstream of the final effluent outfall was undertaken as part of the flow and load survey referred to in section 2.9. BODs levels upstream of the existing final effluent outfall were reported to be less than 2 mg/I on two of the three days on which samples were taken. On the third occasion a level of 8 mg/l was recorded suggesting that the stream may have suffered a pollution incident or that the sample was otherwise unrepresentative of average conditions. In either case, this measurement (when taken in isolation) would suggest that the assimilative capacity of the stream had already been For inspection purposes only. exceeded. Consent of copyright owner required for any other use.

Based on the 2 mg/l measurement and for a 25/35 final effluent discharge standard as required under the Urban Wastewater Treatment Regulations, the BOD of the fully mixed final effluent/receiving water combination at the 95th percentile flow immediately • downstream of the final effluent outfall would be raised by around 5.5 mg/l to 7.65 mgt!. This would generally be viewed as unacceptable in a freshwater stream as it is above 5 mg/l BOD which is normally accepted as the limit (assimilative capacity) for BOD. It is accordingly proposed to specify a 10mg BOD/10 mg SS discharge standard. A discharge of this standard is predicted to increase BOD levels in the receiving water downstream of the final effluent outfall by around 2.0 mg/l at the ninety fifth percentile flow. For a background level of 2.0mg/l, the effluent would be safely assimilated by the stream even in low (95 th percentile) flow conditions.

The Dingle Penninsula including Tralee Bay is an exposed Atlantic location which experiences a vast water exchange on each tidal cycle. The assimilative capacity of the bay itself in terms of BOD, phosphates and nitrogen is immense and a discharge of treated effluent from a small treatment plant such as that proposed at Castlegregory would have a negligible impact.

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5.3.4 Freshwater Fish Directive

The regulations made pursuant to the S.1. No. 293/1988: European Communities (Quality of Salmonid Waters) Regulations, 1988 provide for the maintenance of minimum water quality standards in certain designated rivers .. Maximum concentrations are specified for a number of parameters including BOD, suspended solids, ammonia, ammonium, copper, zinc, dissolved oxygen, nitrites and water temperature. The tidal channel carrying the treated effluent from the existing (and proposed) WWTP at Castlegregory is not a designated salmonid water and no specific additional treatment of the effluent is required in connection with these regulations.

A detailed programme is being undertaken by Kerry County Council both upstream and downstream of the outfall and these assumptions will be validated against the results of this study and a firm decision can then be made as to whether or not further treatment by way of ammonia reduction is required on the treated effluent.

5.3.5 Shellfish Directive

In terms of a shellfish production area, the Tralee Bay area is currently classified as Class B in accordance with the 2004 EU Hygiene Directives. A classification of B means that the shellfish from this area must be purified before being sold for human consumption. Further details can be found in Appendix 3. There is no aquaculture practised in Tralee Bay within the immediate vicinity of Castlegregory. There are commercial oyster beds elsewhere in Tralee Bay at and the Spa. In the circumstances it is suggested that there would not appear to be an immediate requirement for disinfection of the effluent from the proposed Castlegregory WWTP although this may be required in connection with other uses of Tralee Bay as in 5.3.6 below.

5.3.6 Bathing Water Regulations For inspection purposes only. Consent of copyright owner required for any other use.

Both Castlegregory beach and Magherabeg beach are EU designated bathing waters. The designation was made in 1996 and requires local authorities to observe certain minimum water quality standards over the course of the bathing season which extends from mid May to the end of August. The standards relate mainly to bacteriological water • quality and particularly the presence of organisms associated with sewage including faecal coliforms, faecal streptococci, and viruses. Where sewage discharges take place to watercourses or to the open sea adjacent to bathing waters, the presence of large populations of bacteria in the treated effluent can pose a significant risk to compliance with the bathing water standards. For larger WWTWs with (long) sea outfalls, the dispersion and migration of the effluent plume is often mathematically modelled to assess the risk to compliance with the bathing water standard and to determine the optimum point for the discharge for the treated effluent. In the case of Castlegregory, the final effluent outfall will discharge to a tidal channel which flows out to Tralee Bay directly across the bathing beach. Accordingly the treated effluent would be expected to mix with the sea water along the shoreline. This would pose a significant risk of bacteria and viruses appearing in the bathing water above the limits specified in the regulations. Disinfection of the final effluent is proposed to improve the prospects of compliance with the regulations. However it is noted that the same tidal stream carries flows from much further inland including runoff and discharges from farms etc. Sampling of the receiving waters upstream of the final effluent outfall from the existing WWTP indicates that the stream carries a significant bacteriological population including faecal coliforms. This suggests that agricultural practices upstream may be

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responsible for contamination of the stream and that the provision of disinfection at Castlegregory WWTP in isolation may not ensure compliance with the bathing regulations. 5.4 Discharge Specification

Based on the foregoing as well as consultations with the South Western Regional Fisheries Board and the Department of the Marine, Communications and Natural Resources, the following final effluent discharge standards as detailed in Table 5.3 are proposed.

Parameter Concentration Unit .1" I------10 mq/I BOD.:....=:..=..:..:.=:..:..--...:...--+----= L..-----'S:....:u....:.s.L.e.;:..n--'d.....::e....:..d--'S.....::o_lid.;:..s'----_--'--__---1,....,:0,-----t--:....:m~g,/I-----i

Table 5.3 • Design PE and Wastewater load for Treatment Works Disinfection of final effluent from the treatment plant via UV treatment is also proposed and a faecal coliform geometric mean concentration of approximately 1,000 per 100ml with a maximum of 2,000 per ml may be indicative of the requirements to be agreed at detailed design stage for the faecal effluent discharge standard.

5.5 Wastewater Treatment Plant Site

The location and an indicative layout of the proposed WWTP is shown on Drawing 2596­ CG-15.

There are a wide variety of treatment systems capable of meeting the final effluent discharge standards proposed Forfor inspectionthe Castlegregory purposes only. plant. These systems would include Consent of copyright owner required for any other use. conventional activated sludge plants (with or without primary settlement), Rotating Biological Contactors (RBCs), constructed wetlands and combinations of the above. All of these systems have associated advantages and disadvantages in terms of differing capital costs, maintenance requirements, sludge production and associated land/area requirements.

The type of wastewater treatment that will be ultimately employed at Castlegregory will largely depend on the outcome of the procurement options assessment proposed in the project brief and on the specifications used in terms of the required design life for tanks and process equipment. A possible WWTP layout is detailed on Drawing Number CG-15. This layout is based on an activated sludge extended aeration process with UV disinfection. The layout should be taken as indicative only and has only been prepared to demonstrate the adequacy of the site in terms of its ability to accommodate one proposed wastewater treatment option. For costing purposes the extended aeration activated sludge plant was used. The dimensioning of the plant and equipment used in the indicative layout is given in Appendix 5

5.6 Sludge In accordance with the 2003 County Kerry Sludge Management Plan, sludge hub centres are to be established at Tralee, and at Waterville/. These hub centres will treat wastewater treatment sludges arising from the wastewater treatment plant at the hub centre as well as sludges from outlying towns and villages which would

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EPA Export 26-07-2013:15:01:14 Kerry West Villages Sewerage Schemes - Castlegregory T.J. O'Connor &Associates • October 2007 be imported to the hub in tankers or skips. The sludge would be treated at the hub centre to allow it to be re-used as an agricultural fertiliser (biosolid).

The plan makes no specific recommendations in respect of sludges from the Castlegregory WWTP. However the Dingle peninsula including Castlegregory would naturally fall within the catchment of the Tralee hub centre and it is expected that sludges arising at Castlegregory WWTP would be taken to Tralee for treatment. The plan does not provide any specific recommendations in respect of sludge storage at the outlying plants. However storage for between 1 to 4 weeks is commonly provided depending of the size of the WWTP. For Castlegregory it is suggested that storage for not less than 2 weeks is provided. This can be provided by making adequate provision in the dimensioning of primary tanks where such are proposed. Alternatively dedicated sludge storage tanks or a picket fence thickener would need to be provided to store waste activated sludge arising.

5.7 Outfall I Foreshore Licence

It is proposed to use part of the existing 450mm diameter outfall pipe to carry final effluent from the proposed WWTP. A new 450mm diameter pipe from the site of the proposed WWTP is to be laid to connect with the existing pipe. As it is proposed to use the existing outfall to discharge the treated effluent it should not be necessary to apply for a foreshore license in connection with the new WWTP.

For inspection purposes only. Consent of copyright owner required for any other use. •

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