Discharge Licence applications – Further information.
Discharge Licence D0279-01 Dromahaire
Further information.
1 “At how many times dry weather flow will discharges occur from the stormwater overflow, located at the inlet pipe of the waste water treatment plant
Answer;
The existing plant is discharging at approx 3DWF from the stormwater overflow,located at the inlet pipe of the waste water treatment plant.
The new plant is designed to treat 3DWF at all times with a further 3DWF being stored in a stormwater overflow tank for a period of two hours before being returned through the treatment system. In excess of 6 DWF the flow will storm through a 6mm screen to the river.
2. “Provide an update of any works carried out at or details of any funding provided for the Dromahaire WWTP under the Water Services Investment Programme – Leitrim Towns and Villages sewerage scheme Feasability study.”
Answer;
Dromahaire WWTP is part of the Leitrim Towns and Villages sewerage scheme Bundle No.1 which is currently under construction. This scheme will provide new and upgraded sewerage infrastructure in eleven Towns and
Villages including Dromahaire. For inspection purposes only. Consent of copyright owner required for any other use.
The networks improvement works have been completed in all towns and villages at a cost of €8.0 million. The eleven new treatment plants are being procured as a Design Build Operate contract at a cost of €10.5 million. These works commenced in January 2009
A new Waste Water Treatment Plant on a green field site is currently under construction at Dromahaire and is programmed for completion and commissioning in November 2010. The cost of the new treatment plant at Drumahaire is approximately € 1.26 million. This Plant will be operational by the end of 2010 and the existing plant will be decommissioned early in 2011.
3. “Provide information on the future projected loading on the WWTP when the plant becomes fully operational at 2,200 p.e. i.e. Population equivalent influent flow rates and discharge rates.”
The basic design Parameters for the new Wastewater Treatment plant are as follows;
Population Equivalent 2,200
EPA Export 26-07-2013:15:30:46 Dry Weather Flow (L/s) 5.7 Peak flow to treatment (L/s) 17.2 Minimum outfall capacity (L/s) 68.8 Average BOD.5 (kg/day) 132.0 Suspended Solids (kg/day) 165.0 Total Phosphorus (kg/day) 4.95
The design of the new plant allows for fluctuations in the average daily BOD, SS, Phosphorus and Nitrogen levels up to 125% of the specified influent daily loads on a continuous basis. The design of the new plant will be capable of achieving Final effluent Discharge Limit Standards up to 3 DWF or peak flow. The Final Effluent Discharge Limits for Dromahaire are
BOD5 25 mg/l Total Suspended Solids 35 mg/l COD 125 mg/l MRP 2.0 mg/l P
4. “When the new plant is fully operational will SW3 and SW4 still be in use?
Answer; The Storm water overflows SW3 and SW4 will no longer be in use when the new plant is fully operational.The existing Storm Water overflow (SW2) at the existing WWTP will be abandoned. The only storm water overflow will be at the new WWTP and all solids will be removed on a 6mm screen.
5 “Where it is considered that any of the substances listed in Annex X of the Water Framework Directive (2000/60/EC) or any of the relevant pollutants listed in Annex VIII of the Water Framework Directive (2000/60/EC) are being discharged from the waste water works or are seen to be present in the
receiving water environment For inspectiondownstream purposes only. of a discharge from the works (as a Consent of copyright owner required for any other use. result of any monitoring programme) the applicant shall screen the discharge for the relevant substance.
Answer;
It is not considered by LCC that such substances listed in Annex VIII & II (formely Annex X) are being discharged at Dromahair WWTP or are present in the receiving waters.There is no Industrial Licence discharging to this plant and the table of Dangerous Substances results already submitted in the application is in compliance with the Dangerous Substances standards and therefore there is no screening required .
However the EPA have a monitoring point 1.8km d/s of Dromahair Bridge(d/s of existing and proposed plants) of which any results recorded, we have requested a copy of same. Until we receive these results we cannot comment on same.
EPA Export 26-07-2013:15:30:46 6 “Assess the likelihood of significant effects of the waste water discharges from the Dromahair agglomeration on the relevant European site(s) by referring to Circular L8/08 ‘Water Services Investment and Rural Water Programmes – Protection of Natural Heritage and National Monuments’ issued by the Department of Environment ,Heritage and Local Government. In particular the flow diagram in Appendix 1 should be completed and the results of each section recorded. Provide details of the results of this assessment within six weeks of this notice. If significant effects are likely then an appropriate assessment must be carried out and a report of this assessment forwarded to the Agency within six weeks of the date of this notice.
Answer;
Dromahair WWTP
1. “Is the development in a nature conservation site?”
LCC Response Yes The receiving water for Dromahair WWTP is the River Bonet. The River Bonet is part of the Lough Gill SAC .
ASSESS IMPACTS
Dromahair Wastewater Treatment Plant
“Assess Impacts” is required as per Circular L8/08
For inspection purposes only. Consent of copyright owner required for any other use. Status of existing wastewater treatment plant The original WWTP at Dromahair was commissioned in 1977 and designed to cater for a population equivalent (PE) of 500. In 2004 a package plant was installed which added a further 600PE to the original plant bringing the total PE to 1100. The plant is currently receiving wastewater with a strength equivalent to 901PE. The treated wastewater discharges to the Bonet River and enters Lough Gill.
Nature conservation sites located within 5km of Dromahair WWTP A search on the National Parks and Wildlife Service Map viewer web site found that 10km G73 and G83 encompassing the Lough Gill catchment found that the Owenmore, Bonet and Shanvaus Rivers were Special Area’s of Conservation (SAC) and that Lough Gill was an SAC and a proposed Natural Heritage Area (NHA). According to the National Parks and Wildlife Service synopsis of Lough Gill (Site Code: 001976) this site comprises Lough Gill with Doon Lough to the north-east, the Bonet River as far as but not including Glenade Lough, and a stretch of the Owenmore River near Manorhamilton in Co. Leitrim. Lough Gill itself, 2 km east of Sligo town, lies at a geological junction of ancient metamorphic rocks which produce acid groundwater and limestone which dissolves in the groundwater. The large 8 km long lake has steep limestone shores and underwater cliffs and is over 20m deep in places. The lake appears to be naturally eutrophic, and thus represents a habitat listed on Annex I of the EU Habitats Directive. The site is a candidate SAC selected for
EPA Export 26-07-2013:15:30:46 alluvial wet woodlands a priority habitat on Annex I of the E.U. Habitats Directive. The site is also selected as a candidate SAC for old Oak woodlands and natural eutrophic lakes, both habitats listed on Annex I of the E.U. Habitats Directive. The Bonet River is an important Salmon River.
Habitats and Species that are Site Water Dependent on the Bonet River A search on the National Parks and Wildlife Service Map viewer web site found that 10km G73 and G83 grids identified Small-White Orchid (Pseudorchis albida) at Lough Gill in 1899, at Lough Anelteen in 1989 and 1991, at Carns Hill in 1989, at Ballynamona in 1991 and at Ballure in 1991, Fallow deer (Dama dama) at Ballintogher West on 06/10/1991, Fallow deer (Dama dama) at Dromahair on 12/02/1992, Otter (Lutra lutra) at Dromahair on 12/02/1992, small-white orchid (Pseudorchis albida) at O’Rourke’s Table in 1934, at Curraghan in 1991, at Moreragh in 1993, at Curraghan in 1993 and at Banagher in 1994. According to the National Parks and Wildlife Service synopsis of Lough Gill (Site Code: 001976) this site is selected for the following species listed on Annex II of the same directive - Sea Lamprey, River Lamprey, Brook Lamprey, Whiteclawed Crayfish, Atlantic Salmon and Otter.
The aquatic macrophyte flora is very limited, probably due to the rapid increase in depth around most of the margin. Species such as pondweeds (Potamogeton spp.) are present, as well as Shoreweed (Littorella uniflora). Where the lake shore has a shallow gradient, some swamp vegetation occurs, mainly dominated by Common Reed (Phragmites australis), with Common Club-rush (Scirpus lacustris) and sedges (Carex spp.).
The site contains Old Oak Woodlands, a habitat listed on Annex I of the EU Habitats Directive. These woods are dominated by Oak (Quercus spp.), Rowan (Sorbus aucuparia) and Willows (Salix spp.). Strawberry Tree (Arbutus unedo), in its most northerly site in the world, Yew (Taxus baccata), in abundance, Bird Cherry (Prunus padus), a Red Data Book species, and the nationally scarce Rock Whitebeam (Sorbus rupicola) can also be found here. Some areas of conifer plantation occur in association with these woodlands. The site is also notable for the presence of Alluvial
Forest, a priority habitat liste d on For Annex inspection purposesI of theonly. E.U. Habitats Directive, which is Consent of copyright owner required for any other use. found along the banks of the Garvoge River and at the mouth of the Bonet River.These wet woodlands are dominated by Alder (Alnus glutinosa) and Willows. Areas of unimproved wet and dry grassland occur within the site, the former particularly by the lake and the latter well developed in the north-east of the site and in the vicinity of O’Rourke’s Table. Heath-covered hillsides above the woods are dominated by Heather (Calluna vulgaris). Both the woods and the mountains are used by a large herd of Fallow Deer.
The site is of considerable importance for the presence of four Red Data Book fish species that are listed on Annex II of the E.U. Habitats Directive - Brook Lamprey (Lampetra planeri), River Lamprey (Lampetra fluviatilis), Sea Lamprey (Petromyzon marinus) and Atlantic Salmon (Salmo salar). The Lough Gill system gets a very early run of spring salmon while the Bonet holds stocks of salmon from spring right through to the end of the season.White-clawed Crayfish (Austropotamobius pallipes), Otter and Pine Marten are well established on this site, the former, both being Annex II species. The woodlands have a fauna which includes several rare snail species. The site supports several rare plant species, including Yellow Bird's-nest (Monotropa hypopitys), Lady’s Mantle (Alchemilla glaucescens), Ivy Broomrape (Orobanche hederae), Black Bryony (Tamus communis), Intermediate Wintergreen (Pyrola media) and Bird's-nest Orchid (Neottia nidus-avis). There is also an unconfirmed record for Melancholy Thistle (Cirsium helenioides) from the eastern side of the site.
EPA Export 26-07-2013:15:30:46 Lough Gill supports only low numbers of wintering waterfowl, mostly Mallard (<150), Tufted Duck (20-30) and Goldeneye (<20). A small colony of Common Terns breed on the islands (20 pairs in 1993), while Kingfishers are found on the lake and rivers. Both of these species are listed on Annex I of the E.U. Birds Directive. A colony of Black-headed Gulls (63 pairs in 1992) occurs with the terns. The woods support a good diversity of bird species including Jay, Woodcock and Blackcap. The site is of importance for three habitats listed on Annex I of the E.U. Habitats Directive, including one with priority status. It is also noted for the high number of rare or scarce animal and plant species. Detailed ecological studies have been carried out on the lake in recent years and a management plan for Lough Gill catchment was produced in 1998 for Sligo County Council.
Impact of Treated Wastewater discharges on the Bonet River The existing WWTP at Dromahair is monitored for pH, BOD, COD, SS, Total Nitrogen (TN) and Total Phosphorus (TP). The discharge limits set for BOD, COD and SS are 25, 125 and 35mg/L respectively. Limits of 15 and 2mg/L are set for TN and TP respectively. These limits are laid down in the Urban Wastewater Regulations 1994. Results for the period 15/01/2008 to 28/05/2009 inclusive showed that 67% of treated wastewater samples exceeded one or more of these limits. It is important to note that these samples were taken from the recognised discharge point at the WWTP and not from storm overflow discharge points. What immediate impact the discharges are having on the receiving water is unknown. What is known is that the Bonet River downstream of the primary discharge from Dromahair WWTP complied with the Dangerous Substances and Phosphorus Regulations. According to the Phosphorus Regulations the Q rating for downstream of Dromahair WWTP was Q5 indicating good water quality.
The Bonet River downstream of Dromahair WWTP in compliance with all Salmonid standards with the exception of ammonia. The limit set in these Regulations is ≤0.02mg/L NH3 and the result obtained was <0.073mg/L. The same result was obtained upstream of the primary discharge to the WWTP and may have been attributed to sources other than the domestic sewerage system. There are storm water overflows upstream of the primary discharge at Dromahair WWTP but discharges
from them are rare.It must also be For inspectionkept in purposes mind only. that the level of ammonia obtained Consent of copyright owner required for any other use. upstream and downstream of the WWTP was less than 0.073mg/L i.e. below the detection limit of the method used and in actual fact may have been less than 0.02mg/L NH3.
Mitigation Measures The original WWTP at Dromahair was commissioned in 1977 and designed to cater for a population equivalent (PE) of 500. In 2004 a package plant was installed which added a further 600PE to the original plant bringing the total PE to 1100. The plant is currently receiving wastewater with a strength equivalent to 901PE.
Phosphorus reduction facilities were installed at the existing wastewater treatment plant in 2004 to ensure that phosphorus levels within the treated wastewater were below the limit laid down in the Urban Wastewater Regulations. A new wastewater treatment plant is under construction at Dromahair as part of the Leitrim Town and Villages Sewerage Improvement scheme. This plant, which is to be built under a Design, Build and Operate (DBO) contract, will provide treatment for current loadings from the town and any future increases in population. It will eliminate flows from the Storm water overflow at the current treatment plant and will also treat the wastewater to a standard that will meet current legislation. This will ensure that there is no significant risk of pollution to the environment. Work on the new plant was due to begin in April 2009.
EPA Export 26-07-2013:15:30:46 The existing WWTP at Dromahair is being managed by an external contractor who will be the DBO contractor for the new WWTP. This contractor reports to Leitrim County Council on a regular basis regarding the management of the plant.
Conclusion Dromahair WWTP is monitored by Leitrim County Council and the DBO Contractor to ensure that all discharges from this plant comply with the Urban Wastewater Regulations and do not adversely affect its receiving waters. Any problems affecting the ability of Dromahair WWTP to effectively treat its wastewater are managed by Leitrim County Council in an expedient manner.
7.“Provide the 50%ile , 95%ile and dry weather flow for the River Bonet.Carry out assimilative capacity calculations for the discharge from the primary discharge point. 95%ile flow shall be used to calculate the capacity of the receiving waterbody for BOD, Suspended Solids, nitrates, COD, and total phosphorus.In addition ,a calculation shall be presentedfor the capacity of the surface waterbody, based on the 50%ile flow, for ortho-phosphate.Provide all the figures used in your calculations.
Answer;
The following figures used in the Assimilative capacity calculations below were received from the EPA on 27/07/09 for hydrometric data nearest the primary discharge location at the plant.
River Bonet (coordinates 179950E, 331483N) for Existing Plant Estimated long-term 95%tile (based on flow data from station 35011) - 0.9m3/s Estimated long-term dry weather flow (based on flow data from station 35011) - 0.29m3/s Estimated long-term 50%tile (based on flow data from station 35011) - 6.64m3/s Catchment area to location - 266km2
Assimilative Capacity (AC) is Calculated by
For inspection purposes only. A= 95%tile flow M3/sec. Consent of copyright owner required for any other use. B= Background median concentration of Dangerous Substance in river ug/l. C= Average volume of discharge M3/sec. D= median dangerous substance concentration of discharge.
Concentration of Dangerous (AxB) + (CxD) substance after assimilation= (A+C)
A B C D AC
BOD 0.9 <2 0.0022 <2 <2
Suspended 0.9 7 0.0022 <3 6.99 Solids Nitrates 0.9 0.23 0.0022 6.8 0.25
COD 0.9 26 0.0022 15 25.97
total 0.9 <0.042 0.0022 0.465 0.04 Phosphorus
EPA Export 26-07-2013:15:30:46
A B C D AC
Orthophosphate 6.64 0.008 0.0022 0.459 0.008
Assimilative Capacity (AC) is Calculated for Orthophosphate using the 50%tile flow of 6.64m3/s
8 “Please clarify the frequency of discharges from SW2, SW3, and SW4. Table E.1(ii), submitted as part of the licence application form, does not provide any discharge information for these overflows, describe the methodology used to determine the frequency of the discharges.
Answer; There are no flow measuring devices present at SW2, SW3 and SW4 so therefore there is no discharge information available for these overflows.
9 “Indicate what percentage of the waste water being treated at the Dromahair WWTP is domestic and what percentage is industrial.
Answer, The Environment Department of LCC have confirmed that there is no Industrial discharge to be treated at Dromahair WWTP.
The Current breakdown of loadings at Dromahair WWTP would be: Non Domestic sector 14.5% Includes all hotels,pubs,schools,resteraunts, And shops Existing Domestic 85.5% Eligible Domestic incl some infill.
10. Provide details on a programme of improvements to ensure that the discharges from the agglormeration or any premises, Plant,methods ,processes, operating procedures or other factors which affect such emmissons For inspection purposes only. will comply with, or Consentwill not of copyright resu ltowner in requiredthe contravention for any other use. of; the Dangerous
Substances Directive2006/11/EC, The water framework directive 200/60/EC, The Birds Directive 79/409/EEC, THE Groundwater directive 80/68/EEC & 2006/118/EC, the Drinking Water Directive 80/778/EEC, the Urban Waste Water Treatment Directive 91/271/EEC, the Habitats Directive 92/43/EEC the Environmental Liabilities Directive 2004/35/EC, the Bathing Water Directive 76/106/EEC and theShellfish waters Directive 79/923/EEC.
Answer;
The Leitrim Towns and Villages sewerage scheme Bundle No.1 for 11 No. Treatment Plants which included Dromahaire is being procured as a Design Build Operate scheme which has as the following requirement ;
“From Section 3.1.4 Compliance with Regulations and Standards
Without in any way derogating from the generality of the scope of the Contractor’s obligations as set out in the Conditions of Contract, the design of the facility shall comply with the requirements set out below.
• All applicable and relevant laws, regulations and administrative provisions.
EPA Export 26-07-2013:15:30:46
• The Sludge Management Plan for County Leitrim contained within section 12.
• Part 8 Planning Documents and approvals, refer to section 5.
• The most recent version of The Building Regulations – Technical Guidance Documents (published by the Department of Environment).
• SI No. 254 of 2001 – Urban Wastewater Treatment Regulations 2001.
• S.I. No. 258 of 1998 – Local Government (Water Pollution) Act, 1977 (Water Quality for Phosphorus) Regulations, 1998.
• The general ISO and European wastewater treatment regulations including: