Request for information to substantiate the conclusion that the current energy-from-waste facility at Edmonton needs replacing

REF: Request for information about the status of the existing energy-from-waste facility at the Edmonton EcoPark

1. Your request - Thank you for your request of 1 April 2021 regarding the above. This request is being handled under the Environmental Information Regulations (EiR) 2004 and has been allocated the reference number 2021-109[1]. I apologise for our delay in responding.

1.1        You asked if we could supply:

All the documentation (including, but not limited to, technical assessments, financial models, expert opinions, minutes of meetings etc) that led to the NLWA to conclude:

1.           That the current incinerator is ‘failing’: The case for the new incinerator is often made on the basis that the current incinerator is ‘failing’. This was said again by Rowena Champion at a meeting hosted by the Islington Labour Environment Forum on 22nd March 2021. It is not clear what ‘failing’ means in this context, but I can only assume she meant that the incinerator is no longer burning waste effectively- its function. I would therefore like to see all documentation that substantiates the point that the incinerator is no longer effective.  

2.           That the current incinerator needs to be rebuilt, rather than renovated; that the lifetime of the current incinerator cannot be extended beyond 2027 (the latest date identified by the NLWA for the new incinerator to come online) through renovation: I would like to see all the assessment that substantiate the point that the incinerator is beyond repair (for example, feasibility assessments on extending the incinerator’s lifetime through repair)

3.           That the current incinerator poses no risk to workers and communities: Jon Burke, when NLWA board member made a point that the incinerator could ‘fall over at any moment’. https://www.hackneycitizen.co.uk/2020/02/24/council-seeks-massive-drop-…

You requested “ …………. all documentation to understand what is meant by this, such as risk and likelihood assessments of such a failure. If the current incinerator is indeed at risk of ‘fall(ing) over at any moment’, I would like to see all safety assessments with regards to the health and safety of workers and communities.”

2. NLWA Response to requests 1 and 2​​​​​​

2.1 In response to your request for information, by way of background to the information we are supplying - the existing energy-from-waste (EfW) plant at the Edmonton EcoPark is 50 years old. The plant has been maintained and upgraded throughout its life, most extensively in 2004 and 2005 to meet the requirements of the Waste Incineration Directive (WID), (the requirements of which are now transferred directly from Waste Incineration Directive to the Industrial Emission Directive (IED)), and currently operates to a range of standards including:

2.1.1 The Environmental Permit for the facility which is issued by the Environment Agency (EA) – Permit number: YP3033BE

2.1.2 Health and Safety regulations

2.1.3 Building Regulations

2.2 However, by the time the plant is decommissioned it will be the oldest facility in  Europe that we are aware of. During its life it has diverted more than 21 million tonnes of residual waste from landfill, but it is not as efficient at converting waste into energy as modern facilities, is difficult to maintain and whilst it has been maintained and upgraded to meet current standards, this cannot continue.

2.3 As the plant has been operating for so long and includes substantial infrastructure which differs significantly from modern equipment, the condition and operation of the facility is closely managed and maintained.  The Authority and LondonEnergy Ltd additionally commission specialist regular condition survey reports.  These review the operation of all parts of the facility, identify investment needs and make observations as to potential challenges.  I enclose the most recent (2020) condition survey for the plant, written by consultants Ramboll.  

2.4 Any redactions in the report are made for reasons of:

2.4.1 Commercial confidentiality – under Regulation 12 (5) (e) i.e. where disclosure would have an adverse effect on commercial or industrial information where such confidentiality is provided by law to protect legitimate economic interest; or

2.4.2 They are parts of the report which cover issues outside the scope of your request.

It is necessary to consider the public interest arguments for issuing and for withholding information redacted under Regulation 12 (5) (e).  The public interest argument for issuing the redacted information would be that by disclosing the costs of the investment required this would aid understanding of the scale of the costs of repairs to the existing facility which may be helpful to the requestor.

The public interest argument for withholding the redacted information would be that the financial information which has been redacted is commercially sensitive for the operator, LondonEnergy Ltd in terms of ensuring that the company is able to secure best value for the company and its shareholder (NLWA) when procuring necessary investment. Secondly the request is for information which ‘substantiates the point that the incinerator is no longer effective’ as well as information to ‘substantiate the point that the incinerator is beyond repair’ the remainder of the report provides this validation without the need for financial information too.

2.5 Key points to note in the report enclosed are as follows, using directly the words in the Ramboll report (our wording in square brackets):

​​​​​​​2.5.1 Inappropriate Design: [Some parts of the design of the existing plant make operating the facility more difficult than it would be in a modern energy-recovery-facility (ERF)].

​​​​​​​2.5.1.1 Bunkers - Division of the bunker into [X] sections is a disadvantage from a waste mixing point of view. ……it is unrealistic to consider changing this structure to create a large, single undivided bunker.

​​​​​​​2.5.1.2 Rolling grates – It should be noted that [while the Edmonton facility has rolling grates] modern new built EfW facilities are often equipped with moving grates. The moving grate concept facilitates an even distribution of the waste on the grate allowing a better air flow distribution.

​​​​​​​2.5.1.3 Boilers –The design of the LEL boilers is not ideal. The primary fault in boiler design is that the radiation pass is too small, causing two major problems:

•  Non-conformity with the WID/IED retention time demand of 850°C/2s. However, LEL has achieved a derogation for the retention time requirement; and
• A very limited superheater lifetime of X compared to a normal super heater lifetime of 5 to 8 years on new plants with similar steam parameters.

Rather than an absolute requirement, the 850˚C two second obligation is derived from an empirical correlation to the production of lower emissions. At installations where the operator can demonstrate suitable compliance with emissions, and other, requirements of the Directive, the requirement holds less precedence. This also reflects the fact that the cost implications of replacing and resizing furnaces may be considered to be excessive in relation to the marginal improvement in emissions achievable.

​​​​​​​2.5.1.4 [This means that whilst Edmonton is compliant now and operates well within the emissions limits set, there is a risk that as and when emission limits tighten, the existing facility will not be able to comply, and that the Environment Agency derogation will be withdrawn, and the facility will have to shut down. The Ramboll report notes that]:

“In the period up to 2025 it is considered that with a continuation of the continued good emissions record from the Edmonton facility there is a low risk of this derogation being withdrawn. However, in the longer term, with a greater proportion of plants achieving emissions well below the IED emission limit values, it is Ramboll’s view that the risk of a potential withdrawal increases.”

​​​​​​​2.5.1.5 In the event that the derogation is revoked, significant redesign of the combustion chamber and boilers would be required, with notable civil design and planning implications. The remedial work would also require significant outages. 

​​​​​​​2.5.1.6 Upgrades [put strain on older original components] – e.g. The waste pusher [feeder ram] has one cylinder. At every outage the cylinder is replaced with an overhauled cylinder fitted with new seals. The scraper is usually replaced at every outage and rails are replaced when necessary (about every second outage). Following the installation of the auxiliary burners/start-up burners during the WID upgrade there was an incident where the waste pusher overheated, causing the seals to be destroyed and leading to hydraulic oil leaks. Forced cooling is now employed and the feeder ram is retracted at start-up and shut-down to avoid both overheating and hydraulic oil leakages.

​​​​​​​2.5.1.7 Extensive repair and replacement required - Some parts of the building are in poor condition due to their age with extensive repair and replacement required. LEL has an ongoing programme to carry out repairs and rectify damage, but the list below provides an indication of the sorts of problems that are occurring, and the requirements being placed on the operator as a result:

​​​​​​​2.5.1.8 The metal cladding above the concrete bunker is in poor condition, covered in rust and some sections have broken away.

​​​​​​​2.5.1.9 The EfW plant cladding is generally showing signs of surface corrosion at numerous locations and there has been some mechanical damage. Cladding will require regular maintenance and repair to keep the buildings watertight.

​​​​​​​2.5.1.10 The 3.3 kV switchgear is over 50 years old. It is a single busbar with air insulation with air circuit breakers. A contract with of XXX of X has been signed to manufacture XX switchboards because of the age of this equipment.

​​​​​​​2.5.1.11 The flue gas treatment (FGT) reactor towers are suffering from ‘significant corrosion’ The sheet cladding covering the insulation has given rise to problems and repair work. The original rivets have to a great extent disappeared due to corrosion, which has led to loosening of the cladding sheets.” Ramboll concludes that “From visual inspections the condition of the towers is continuing to deteriorate with on-going repair and maintenance is requirements [required].”

​​​​​​​2.5.1.12 The stack pipes have been found to be damaged where lagging has fallen off. Lagging is held in place with steel bands which have corroded and broken, allowing this to occur. The corrosion damage had allowed two large holes to form (one was approximately X) which have been repaired.

​​​​​​​2.5.2 Increased risk of components failing – [e.g.] The main 11 kV switchboard is double busbar compound insulated with oil circuit breakers and comprises XX circuits. The switchboard is the X model of switchgear manufactured by X X X manufacture and is now 50 years old. The fact that the switchboard is still in operation having never been de-energised is testament to the build quality of the equipment and the maintenance regime afforded by the O&M staff during the lifetime of the switchboard. However, it should be noted that O&M staff have indicated that the compound insulation has been leaking.

​​​​​​​2.5.3 An incident in the past when one of the 11 kV circuit breakers did not close properly highlighted the potential for failure. Incomplete closure of one of the oil circuit breakers would create high temperature arcs within the oil thus detonating the oil. The resulting explosion would lead to catastrophic failure of the switchboard. The 11 kV switchboard is one of the most critical items of equipment within the plant such that failure of the switchboard would result in a total loss of electrical supply to the plant and therefore total plant shutdown

LEL has signed a contract with X of X for the manufacture of a new 11 kV switchboard comprising X circuits.

​​​​​​​2.5.4 Changes to operational regimes extend the plant life – [Changes to the operational regime can extend the life of the facility. As an example]: LEL’s boiler and live steam system is designed for 460 °C. However, the plant has been operating at about 410 °C. Usually system and material lifetime can be prolonged for 20 years for every 10 °C of reduction in operating temperatures from the design temperature. This correlation indicates a much-prolonged lifetime for LEL’s steam system.

​​​​​​​2.5.5 Difficulties of obtaining spare parts – [given the age of the Edmonton facility – the difficulty of obtaining spares is a risk for the operation]. LEL’s main turbines are almost over 45 years old. Securing spare parts for these turbines can be difficult. Therefore, most turbine parts must be ‘reverse engineered’. To date, LEL has not experienced this as being a problem and holds critical spare parts on site. [However, as the system ages the risk of not being able to obtain spares can only increase.]

​​​​​​​2.5.6 Extension beyond design life – [By 2025, many of the components will reach a lifetime approaching twice their original design life. As an example, the steam turbine[s]] has been on duty for almost twice their design lifetime….. whilst there are neither indications of creep damage nor a notable risk of crack propagation, Ramboll recommends a remaining lifetime study of steam turbines. [However, some aspects of the facility will not be fit for purpose, even with retrofits and repairs going forwards, particularly if and when operational standards tighten.] Reducing NOx emissions below 100-120 mg/Nm³ at Edmonton would require installation of Selective Catalytic Reduction (SCR). This would be costly and complicated by severe physical restrictions on site and there may be planning issues associated with the introduction of this extra cleaning step.

​​​​​​​2.5.7 For all these reasons it is now considered necessary to replace the existing facility.

​​​​​​​2.6 In addition to the attached report, we have also recently highlighted to another requestor that a report on the options for replacing the existing EfW plant at Edmonton was produced in 2017. The report is available here: https://www.nlwa.gov.uk/sites/default/files/2020-05/3-dco-update-and-next-steps-web.pdf  and is highlighted in the response to information request 2021-119 and available in our Scheme of Publication here: https://www.nlwa.gov.uk/ourauthority/scheme-of-publication - please see Appendix A to the report.

​​​​​​​2.7 Section 5 of the appendix discusses the condition of the current ERF and the report additionally considers two options for rebuilding the current plant.

3. NLWA response to your request number 3

3.1 You have also requested information to show that the current incinerator poses no risk to workers and communities. The current facility is operated by LondonEnergy Ltd, who make available emissions performance on their website at https://www.londonenergyltd.com/community/emission-data/. In addition LondonEnergy Ltd has a strong health and safety record which has recently enabled them to gain the Silver award of the Royal Society for the Prevention of Accidents (RoSPA).  If you would like any further information from  LondonEnergy Ltd, please use the contact e-form available here: https://www.londonenergyltd.com/contact-us/ Further details about LondonEnergy’s approach to information requests is available here: https://www.londonenergyltd.com/about-us/freedom-of-information/

4. I trust this response provides the information you are looking for regarding the status of the energy-from-waste plant at the Edmonton EcoPark and why it needs to be replaced. If I can be of any further assistance, please do not hesitate to contact me if you have additional and/or more specific requests for information.

If you are dissatisfied with this response and wish to appeal, please reply to this email or submit a complaint via our website complaints page at: https://www.nlwa.gov.uk/enquiry-form

Your request should be submitted to us within 40 working days of receipt by you of this response.   

If you are still not satisfied, you have a right to appeal to the Information Commissioner: https://ico.org.uk/global/contact-us/email/

Information Commissioner's Office

Wycliffe House

Water Lane

Wilmslow

Cheshire

SK9 5AF

0303 123 1113

Yours sincerely,