Construction of New Outfall Sewer
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DEVELOPMENT CONTROL AND REGULATION COMMITTEE 15 August 2017 A report by the Corporate Director Economy and Highways _____________________________________________________________________ Application No: 1/17/9009 District: Carlisle City Council Applicant: United Utilities Water Ltd Parish: Dalston Warrington Received: 16 June 2017 PROPOSAL: Construction of new Outfall Structure LOCATION: Land adjacent to Dalston Wastewater Treatment Works, Dalston, Carlisle, CA5 7JU _____________________________________________________________________ 1.0 RECOMMENDATION 1.1 That: a) The Assessment of Likely Significant Effect (ALSE) dated 21 June 2017 undertaken by the applicant , in their position as a competent authority for the purposes of the Conservation of Habitats and Species Regulations 2010, be adopted; b) Planning permission be GRANTED subject to the conditions set out in Appendix 1 of this report. 2.0 THE PROPOSAL 2.1 Planning permission is sought to construct a new outfall for Dalston Wastewater Treatment Works (WwTW) on the western bank of the River Caldew. It is proposed to locate the new outfall approximately 130m south-east of the WwTW at Ordnance Survey Grid Reference NY 337984 551088. 2.2 It is proposed to provide a new outfall as the existing outfall for Dalston WwTW is now remote from the main channel of the River Caldew as this has moved over time resulting in concerns about pollution in the area of the existing outfall. The proposed new outfall would enable final treated effluent flows being discharged from the WwTW to be diluted and dispersed to acceptable levels. 2.3 The proposed outfall structure would comprise a 450mm diameter black plastic outlet sewer pipe set into, and flush with, a reinforced concrete surround and headwall. The headwall would measure 0.9m in width and 1.3m in height and a safety grille would be placed It would project 0.6m above ground level. Concrete wing-walls would project 2m beyond the headwall. These wing-walls would taper down from 1.3m in height at the headwall to 0.3m in height. The majority of the external sides of the wing-walls would not be visible as they would be tied back into the existing river bank profile. It would have a reinforced concrete base with a 1in500 fall, this would measure 1.6m in width at the end of the edge of the wing-wall. At the edge of the wing-walls sheet piles or a concrete beam may be installed to support the riverside edge. The applicant advises that this would be flush with the edge of the river bed so should not be visible even during low flow conditions. The entire outfall structure would have a footprint of no greater than 4m2. 2.4 The outfall would be angled to discharge flows in a downstream direction. Beyond the outfall structure core it is proposed to construct a concrete apron topped with un-coursed stone rubble pitching. This would project up to 6.85m from the outfall edge (covering an area of approximately 16m2) so as to slow the flow and provide an aerating cascade for discharge to facilitate maximum dilution. 2.5 The applicant benefits from permitted development rights in their position as a statutory undertaker. The proposed new pipework connecting the WwTW to the new outfall would be installed underground with the benefit of the applicant’s permitted development rights. 2.6 The applicant intends to leave the existing outfall in place and block the pipe using plugs along the length of it so as to minimise disturbance. 2.7 The temporary construction compound for the works is proposed to be sited adjacent to the south side of the WwTW. 2.8 This application is being reported to Committee as a member of the public has objected to the proposed development. 3.0 SITE DESCRIPTION 3.1 Dalston Wastewater Treatment Works (WwTW) is located approximately 600m northeast of the large village of Dalston in an area known as Lowmill. The WwTW is a relatively small site covering a 1ha parcel of land. It is accessed via an un- named road off the B5299 which crosses the Cumbrian Coast railway line before providing access to the WwTW having passed a small cluster of residential dwellings at Lowmill. A public footpath (Public Right of Way No. 114050) runs along this access road and connects onto a tarmac surfaced cycle path (which is part of the national cycle network route 7) and another public footpath (Public Right of Way No. 114018) which runs between Caldew Secondary School in Dalston and Cummersdale Bay and forms part of the Cumbria Way long distance route. 3.2 The River Caldew runs south to north some 90m to the eastern side of the WwTW. The land between the river and the WwTW is a mixture of deciduous plantation and tall rank/ruderal grassland/scrub vegetation. The outfall is proposed to be sited on a meander upstream of the WwTW in an area where dense continuous scrub covers the western river bank. On the opposite (eastern) side of the river is improved grassland in agricultural use. A public footpath skirts the eastern banks of the river (Public Right of Way Nos. 129001 and 114042) 4.0 SITE PLANNING HISTORY 4.1 There is no planning history relative to the proposed site of the outfall. 4.2 Dalston WwTW was built in the 1960s. The County Council hold records for two previous planning permissions at the site. These are a 1998 consent for the erection of an electrical control kiosk (Ref. 1/98/9015) and a 2007 consent for the construction of ferric dosing kiosk (Ref. 1/07/9007). 4.3 Carlisle City Council granted planning permission for conversion of a barn and outbuilding to provide 3no. dwellings at Low Mill Barn in January 2016 (Ref. 15/0783). This permission included a conditional requirement to construct a Flood Defence Bund to the east and south of this building. An application to discharge Conditions 3 (Scheme for Construction of Proposed Flood Defence Bund) & 6 (Level 2 Survey) of the Planning Permission are currently being considered by Carlilse City Council (Ref. 17/0534). A flood defence bund has already been constructed. 5.0 PLANNING POLICY 5.1 Section 38(6) of the Planning & Compulsory Purchase Act 2004 provides that planning applications must be determined in accordance with the development plan unless material considerations indicate otherwise. Government policy is a material consideration that must be given appropriate weight in the decision making process. 5.2 The Cumbria Minerals and Waste Development Framework’s (CMWDF) Core Strategy 2009-2020 (CS) and Generic Development Control Policies 2009-2020 (GDCP) were both adopted as Development Plan Documents in April 2009. The key policies from the CMWDF relevant to the determination of this planning application are considered to be: . Policy CS 1 - Sustainable Location and Design . Policy CS 4 - Environmental Assets; . Policy CS 8 - Provision for Waste; . Policy DC 4 - Criteria for Waste Management Facilities; . Policy DC 10 - Biodiversity and Geodiversity; . Policy DC 12 - Landscape; . Policy DC 14 - The Water Environment; 5.3 The emerging Cumbria Minerals and Waste Local Plan 2015-2030 (CMWLP) was submitted to the Secretary of State for examination by an independent Inspector in September 2016. The examination of the CMWLP closed when the Inspector’s final report to the County Council was received on 29 June 2017. This report set out those changes necessary to ensure that the CMWLP is sound and legally compliant. The County Council can now proceed to formally adopt the CMWLP so that it will replace the CMWDF. Since the Plan has been found sound, considerable weight can be attached to its planning policies in the decision making process. The emerging policies relevant to wastewater infrastructure are not dissimilar to those within the CMWDF. The key CMWLP policies relevant to the determination of this application are considered to be: . Policy SP1 - Presumption in Favour of Sustainable Development . Policy SP15 - Environmental Assets . Policy DC9 - Criteria for Waste Management Facilities . Policy DC16 - Biodiversity and Geodiversity . Policy DC17 - Historic Environment . Policy DC18 - Landscape and Visual Impact . Policy DC20 - The Water Environment 5.4 The Carlisle District Local Plan 2015-2030 (CDLP) was adopted on the 8 November 2016. Some area-based and thematic policies of CDLP are of some relevance to the determination of this planning application. These are considered to be: . Policy SP 5 - Strategic Connectivity . Policy SP 6 - Securing Good Design . Policy SP 8 - Green and Blue Infrastructure . Policy CM 5 - Environmental and Amenity Protection . Policy GI 3 - Biodiversity & Geodiversity . Policy GI 5 - Public Rights of Way . Policy GI 6 - Trees and Hedgerows 5.5 Dalston Parish Council formally submitted the Dalston Parish Neighbourhood Plan 2015-2030 to Carlisle City Council on 11 May 2017. Carlisle City Council considers the Plan to be legally compliant and it was consulted upon as part of the examination process between 5 June and 17 July 2017. The only policy relevant to the determination of this application is considered to be Policy DNP-E 1 - Landscape, habitats, rural character. This requires development to respect the parish’s landscape, wildlife habitats, rural character, green spaces, footpaths, cycle ways, bridleways, built heritage, archaeological sites and ecosystems and states that proposed developments that would detrimentally affect these environmental features will not be supported. 5.6 The National Planning Policy Framework [NPPF], which was published on 27 March 2012, and the national online Planning Practice Guidance (PPG) suite, which was launched in March 2014, are material considerations in the determination of planning applications. The following sections and paragraphs of the NPPF are considered to be relevant to the determination of this application: . Paragraphs 6-10 - Achieving sustainable development . Paragraphs 11-14 - The presumption in favour of sustainable development .