Final Report
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Island of Seil Wastewater Treatment Options Review FINAL REPORT May 2017 Document History Version Comment V2.0 FINAL Scottish Water FINAL 19 May 2017 Executive Summary 1. PURPOSE The purpose of this report is to provide an overview of Scottish Water’s appraisal of the options available to deliver sustainable wastewater treatment solutions on the Isle of Seil. 2. BACKGROUND a. Original Project A project to provide a first time sewerage and treatment scheme for the Island of Seil (Argyll and Bute) was implemented in the 2006-2010 investment period (SR06), replacing private raw discharges and creating a treatment works serving a population of circa 300 at Balvicar, discharging to a shellfish water (Seil Sound). The Shellfish Water designation ordinarily requires disinfection of the effluent and modelling of the bacterial loading to demonstrate quality. During this period, Scottish Water utilised a relatively new membrane technology in a number of communities where high standards/disinfection was required. This provides a barrier treatment, effectively removing bacteria to deliver a high quality effluent. SEPA therefore accepted a proposal for a membrane treatment plant and network designed to serve a community of up to 500 population with minimal spills. b. Community Experience - Project Delivery The first time sewerage and treatment works was delivered through Scottish Water Solutions. During delivery there was a great deal of community disruption with the laying of a new sewer for the settlement adjacent to the coast. This involved significant intrusion into gardens and private property and extensive roadworks along the single track road that forms the main thoroughfare around the island. The works constructed at Balvicar is directly in front of several properties, along the main tourist route, interrupting a scenic outlook across Seil Sound with a treatment works and unattractive security fencing. There were a number of incidents where the community complained about the performance of contractors. Coupled with the extensive disruption and significant dissatisfaction with the works delivered, the community view of Scottish Water was very poor at the point when the works was commissioned in 2008-9. Further community complaints were raised following the commissioning of the works. The operation of the works introduced noise nuisance to several of the properties nearby, with one resident particularly impacted, leading to extensive dialogue directly and with MSPs. Scottish Water FINAL 19 May 2017 c. Works Performance The works has delivered a high quality effluent through its operation, but it has not been possible to sustain the required level of flow through the works. The membranes have clogged up quicker than was expected leading to extensive maintenance and resulting in spilling untreated screened discharges to the shellfish water more frequently than anticipated when it was designed and licensed. These spills are reported to SEPA as part of the licence condition, and have been a key source of complaint from the community 3. DEVELOPMENT OF A NEW PROJECT Scottish Water has two key drivers to satisfy within the 2015-2021 investment period: 1. a quality enhancement project to provide first time treatment to 8 properties at Seaview Terrace currently served by a raw public outfall; 2. a capital maintenance project to address the performance of the existing works. Isle of Seil Existing Works (Balvicar) Seaview Terrace Seil Sound Shellfish Water Easdale Bay Special Area of Conservation Scottish Water FINAL 19 May 2017 a. Initial Optioneering During 2014-15, initial optioneering indicated that the lowest whole life cost proposal would be to combine both drivers and deliver a single scheme. This would see the replacement of the existing works with a pumping station to pass forward flows for treatment at a community septic tank at Seaview Terrace. Discharging to Easdale Bay would remove the need to meet the shellfish disinfection driver at Seil Sound. Early community engagement on this proposal led to very negative responses and significant escalations within the community. This was compounded by an exceptionally low level of trust due to the previous experience of Scottish Water. Specific objections centred on wildlife (it is designated a Special Area of Conservation) and amenity value (watersports and wildlife tourism) within Easdale Bay. The MSPs Mike Russell and Mike Mackenzie (constituency and list MSPs respectively at the time) were engaged by the community. Dissatisfaction about the delivery and operation of the current works, together with concerns over the new proposals were raised during Scottish Water’s appearance at the Scottish Parliament’s Transport, Infrastructure and Climate Change Committee in December 2015. b. Community Stakeholder Group In June 2016 a Community Stakeholder Group, chaired by Mike Russell MSP, was created with the objective to engage the community in the development of a mutually acceptable option. This was supported by several community information events and the appointment of an independent technical expert (Chris Chubb, former head of Environmental Quality at the Environment Agency) to support community scrutiny. The Group agreed to a process that would see a range of options developed (including those suggested by the community), and appraised through a common project evaluation system. This covered criteria such as customer experience, service and environmental outcomes and costs. Based on assurances given at the Scottish Parliament in December 2015, the community were assured that the ultimate decision making would rest with the SW Board, taking into account the importance of community endorsement. c. Options Appraisal A draft report covering 12 options (variations of 6 core options) was issued to the Stakeholder Group in December 2016 and discussed at the Stakeholder meeting in January 2017, and at a technical meeting with the community, project team and technical experts in March. An appraisal based on cost, feasibility and acceptability grounds, led to two principal options being considered further to satisfy the drivers: Option 1A – creation of a new tertiary treatment works away from the immediate Scottish Water FINAL 19 May 2017 community to replace the existing works, still discharging to Seil Sound Shellfish Water and create a small septic tank to serve the Seaview Terrace residents Option 3 – single large septic tank and UV system located in the vicinity of Seaview Terrace to serve all properties currently connected to the public sewerage system, with disinfected effluent discharged to Easdale Bay Option 1A is viable as it relies on proven technology and would be acceptable to Scottish Water, the community and to SEPA. Option 3 is viable, and in Scottish Water’s view would satisfy the environmental needs, however this option is firmly rejected by the stakeholder group. It would face opposition, delay, technical challenges, legal escalation and further negative feeling in the community. Option Capital Cost Comments 1A £5.6m No major objections anticipated, has stakeholder support 3 £5.5m Includes risk allowance for extensive community resistance and legal challenge, potential outfall extension requirements and project delays Whilst Option 1A is more expensive, on balance it is believed to have the best opportunity to successfully deliver the outcomes and maintain community support. The capital cost of Option 3 relates to the likely augmented solution that would be required (e.g. 3B). The key areas of risk to Option 1A that need to be locked down include securing the relevant regulatory licences, permissions to build (planning and land purchase) and final cost appraisal once the detailed design is completed. 4. CONCLUSION The conclusion of the report is that Option 1A (tertiary treatment discharging to Seil Sound and separate small septic tank at Seaview Terrace) be progressed as the preferred option. This is subject to gaining planning and regulatory permissions and final cost appraisal. This option is believed to have the best opportunity to successfully deliver the necessary regulatory outcomes and maintain community support. 5. PROGRESSING TO DELIVERY Scottish Water FINAL 19 May 2017 In developing this project, informed by a Community Stakeholder Group established with local community members and representatives, there is a need to ensure the wider community is further engaged. Scottish Water will hold an information event with the community to explain the process followed, the solutions identified as viable, and to provide further details of the preferred solution arising from the process. Feedback will be taken from the event to help us to understand and shape the way in which the project might be delivered. The recommended option from this process for a two site solution (stand alone septic tank in the vicinity of Seaview Terrace, and a new treatment works located away from the current site) means they can potentially progress with a degree of independence. Regulatory and planning permissions for each site are currently being sought, which will enable a clearer scope to be finalised and delivery plans to be agreed. The expected timeline for delivering each site is being prepared for further engagement with the community and will be informed by feedback from the community, regulators and planning authorities. Scottish Water FINAL 19 May 2017 Contents 1. PURPOSE ........................................................................................................................................