Additional Information
Background and Full Description
Silent Valley Landfill Site was closed and ceased to receive waste in August 2011.
An extensive Programme of Works comprising capping and restoration of the landfill body was completed in September 2015, thereby achieving Definitive Closure status allowing the Site to officially enter the Aftercare Phase.
The Site was developed in two phases. The initial Phase 1 landfill was operated by Blaenau Gwent County Borough Council (BGCBC) between 1981 and 1994. Records indicate 2 million tonnes of waste was disposed during this period.
The second phase of filling known as Phase 1A, which was essentially a vertical extension of the Phase 1 landfill, was operated by the Council’s waste management company, Silent Valley Waste Services Ltd (SVWS) from 1994 to Closure in 2011. During this period the Site received approximately 2 million tonnes of municipal, commercial and industrial wastes, along with small quantities of Special Waste namely bonded asbestos and palm oil, over an area of approximately 15 hectares.
The Site continues to function as a waste management facility currently, with operation of an adjacent Waste Transfer Station, which receives and processes the Council’s waste and kerbside recycling collections, as well as providing office accommodation for SVWS.
A landfill gas extraction system targeting the Phase 1A landfill only, and a gas engine generator(s) have been active at the Site since 2003. This entire arrangement has been operated under a Lease Agreement with a landfill gas Contractor to generate electricity for commercial exploitation.
The Lease for the current gas generation operation will terminate on 11th December 2022, and thereafter SVWS will continue the generation of electricity from landfill gas extraction under their direct control from this date.
Under the Landfill Directive, SVWS has an ongoing duty to manage any landfill gas produced and to generate electricity where practicable.
An independent review has been undertaken of the landfill gas project on behalf of the SVWS, which estimated that it will be commercially viable to generate electricity from landfill gas until December 2040. It is also estimated that with careful site management, Silent Valley Landfill Site should achieve a net export of 500 kW in 2023, declining at 8% a year thereon.
The proposed duration of the new Contract is therefore, 12th December 2022 to 31st December 2040, and to this end, SVWS is now inviting expressions of interest from suitably qualified and experienced Contractors who will under Contract:
- Supply, install, commission and maintain a gas engine generator at Silent Valley Landfill Site together with such plant, apparatus and associated equipment that is necessary for the generation of electricity and the commercial exploitation of the electricity so generated. It will be vitally important that the Tenderer specifies the correct size engine to optimally match the volume of landfill gas being produced, and in turn avoid the over-extraction of gas which could harm the long-term efficiency and total amount of electricity that can be produced by the project.
- Arrange connection of the supplied gas engine generator to the export cable, and the existing gas extraction system at Silent Valley Landfill Site comprising gas wells, gas well heads, valves, manifolds, condensate knockout pots, flare stack and ancillary pipework.
- Manage, maintain and service the gas engine generator and gas extraction system, to ensure operations comply at all times with the Conditions of the Environmental Permit.
- Manage and control day to day operations to ensure compliance at all times with the Environmental Permit, under the ultimate supervision and control of SVWS.
- Produce and deliver a programme of maintenance for the gas engine generator and the gas extraction system, including balancing of the landfill gas field, condensate management, servicing of the flare, etc.
- Attend monthly operational meetings with SVWS.
- Attend meetings with the Regulatory Authorities as requested, and represent at all times the best interests of SVWS in all communications with the Regulatory Authorities.
- Prepare any landfill gas generation related report / data return, required under the Environmental Permit and submit on behalf of SVWS to Regulator, ensuring any deadline as may be stipulated or imposed therein is met in good time.
- Respond in writing to the Regulator on behalf of SVWS in respect of any query posed.
It is suggested that Tenderers’ proposals include installing of a refurbished or used gas engine generator, to take advantage of its previous accreditation in order to avoid costly and time-consuming electricity network re-commissioning works, due to newly introduced network commissioning rules applicable to new gas engines.
Prospective Tenderers will also be required to demonstrate or provide, to the satisfaction of SVWS:
- A proven ability to successfully operate and manage landfill gas projects of a similar size to Silent Valley Landfill, in particular a proven ability to operate and manage the project at a sub 500kW and sub 300kW level.
- Detailed examples of past operational and efficiency performance in generating electricity at other landfill sites under the Tenderer’s management, and also provide contact details for any of their existing landfill partners from whom SVWS may obtain references.
- A proposed strategy for successfully managing the landfill gas at Silent Valley to ensure its continued economic viability, including proposals and timescales for any future downsizing of the gas engine generator and any planned capital expenditure.
- An estimate of the income and running costs that the Contractor would expect to achieve for the forecasted level of electricity production (to be provided).
- The ability, resources and availability to meet the demands and logistics of managing the landfill gas project at Silent Valley from 12 December 2022 to 31 December 2040. Including details of individuals with a proven track record and experience in landfill gas management and operations.
- Access to accurate landfill gas resource modelling software to periodically analyse and estimate the quantity of the landfill gas that exists at Silent Valley Landfill Site, and the quantity of landfill gas that can be ultimately captured and converted to electricity.
- Commitment to proactively assisting SVWS to develop a collaborative and productive relationship with the Regulatory Authorities.
- Commitment to focusing on the 'health' of the gas field to ensure maximum sustainability and longevity of the Project.
- Details of any gas treatment opportunities to remove for example, silicon compounds or other significant contaminants in the gas fuel feed, which could have a negative impact on engine performance.
- Details of any other proposals to improve gas field yield, improve engine efficiency, reduce maintenance and associated downtime or any other means to achieve an overall uplift in generated output.
Location
Silent Valley Landfill Site is located on the outskirts of Ebbw Vale town in the County Borough of Blaenau Gwent, South East Wales.
The Site is situated in the Merddog Valley on the east flanks of Cefn-y-Areal, above an elevation of 350m AOD and some 1.2 km to the east of the nearest community the village of Waunlwyd, (NGR 31900 20600).
The Site is near the top of the valley which can be described as "blind" and isolated. An area of beechwood, known as Cwm Merddog lies immediately to the east and to the south of the site. This beechwood is designated as a Site of Special Scientific Interest and forms the highest collection of Beech trees in Great Britain.
History
The area has been extensively mined for coal. A number of coal mining adits are known to have been worked within the Merddog valley itself.
The Site was originally used as a disposal facility as early as the 1930s, when steel slag a by-product of the nearby steel making process at Ebbw Vale, was disposed in the valley floor. Records indicate that this practice continued up until 1980, in tandem with a steel slag recovery operation which began circa 1960 removing millions of tonnes of steel slag up until the later 1970s.
Phase 1 Landfill
Ownership of the site passed from British Steel to Blaenau Gwent County Borough Council (BGCBC) in 1981. The latter acquired the site to develop the Phase 1 landfill in the valley to receive municipal waste which was placed on the remaining underlying steel slag.
The Council operated the landfill site until 1994 when waste disposal operations were transferred to the Council’s Waste Management Company Silent Valley Waste Services Ltd (SVWS).
Phase 1A Landfill
The Company operated the Phase 1A landfill under Waste Management License; this phase of filling was essentially a vertical extension of the Phase 1 landfill previously operated by BGCBC, occupying a footprint of approximately 15ha receiving approximately 2 million tonnes of waste during this time, which mainly comprised municipal, commercial and industrial waste streams with a void space created from both landfill and land raise operations.
The Company operated the site on commercial basis not only continuing to receive BGCBC’s municipal waste but also attracting waste inputs from the Commercial and Industrial Sectors. Special Wastes, namely palm oil and asbestos were co-disposed in the landfill during this period the site however, reverted to a non-hazardous disposal facility on successfully applying for a Permit to continue waste disposal operations in 2005.
Commercial extraction of landfill gas focused explicitly on the Phase 1A filling area of approximately 15ha, the landfill gas field comprises
The Phase 1A operations was closed and ceased to receive waste in August 2011. An extensive programme of capping and restoration was completed in November 2015 allowing definitive closure to be granted by the Regulator with the site then entering the aftercare phase.
Landfill Gas Generation Project
A Lease for the current Landfill Gas Generation Project was granted to the incumbent gas generation Contractor in 2002, this Lease will terminate on 11th December 2022. The compound used by the current Contractor for the operation of the gas utilisation plant will therefore become a vacant possession.
The Process
This sourcing/ EOI exercise is being run by the Authority's e-tendering portal Bravo Solutions https://etenderwales.bravosolution.co.uk.
The E-tender references for this project are: Project_51699 and PQQ_33361.
Your expression should include details of your company along with a summary of your experience in operating and managing similar landfill gas generation projects.
Deadline for registering EOI's is 12:00 noon the 16th November 2022 with clarifications allowed until 5:00pm on the 10th November 2022.
(WA Ref:126088)
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