Documents reveals vast list of issues at waste-gasification plant

UK: The facility was considered failed in 2019, but the reasons were not made public until now

The full extent of the problems faced by the developers of a Derby-based waste-gasification plant have been revealed in documents that have been made public for the first time.

Developer Resource Recovery Solutions (RRS), a joint venture of construction firm Interserve and waste business Renewi, was developing the plant for Derby City and Derbyshire County Councils and was originally due to be operational in April 2017.

However, in May 2019 Renewi announced that Interserve had failed to commission the facility and it was now looking at the "complete termination" of the contract.

Despite the plant’s failure becoming public knowledge, the precise details of the problems had not been revealed, until now. 

The information is from the plant’s service delivery plan (SDP), which was obtained by the Sinfin Community Liaison Group (CLG) and passed onto ENDS. It was released to the group after the UK Information Commissioner ruled in favour of local campaigner Simon Bacon, and made the councils provide the waste contract, that led to the plant being built. This in turn led to Bacon asking that the CLG be given a copy of the SDP documents.

The documents reveals the developers stopped keeping commissioning records after “Sept/Oct 2018” indicating the project was considered a failure at that point. 

Crucially, the issues with the plant meant the income from generating electricity from processing waste was “significantly lower than base case”. As a result, there was a significant risk that its Renewable Obligation Certificates (ROCs) would “not be available”.

The facility had secured government-backing in the form of ROCs in May 2018, at the time Renewi said the facility was in the “final stages” of commissioning. However, a year later, the documents reveals that government auditor Ofgem had “queried the basis for [ROCs] accreditation”.

According to the documents, the plant’s turbine “appears to have” a 2MWe shortfall in power production compared with that expected from design data. It also reveals, the turbine and generator “cannot be safely lifted or removed”.

The syngas analysers, installed permanently to gather data for ROCs, “do not work”.

According to the documents, one of the main issues also appears to be at the plant’s front end. Its materials recovery facility (MRF) and mechanical biological treatment (MBT) units were unable to produce enough refuse-derived fuel to “maintain performance of the plant’s lines”. 

This led to the input pit overflowing and delaying delivery of waste to the site. According to the documents, the other issues with the MRF included: 

  • Multiple breakdowns and blockages including shredder breakdowns

  • Non-compliance with the agreed facility recycling target with no evidence that acceptance tests can be passed

  • The actual recycling rate was just 4.8% compared with the 7.4% target rate

  • Air knife used for sorting plastics materials for recycling was failing as there were high levels of plastic film in the rigid plastic bales.

The cranes used in the MBT also “suffered repeat breakdowns”, according to the documents.

The documents also reveals that in the 12 months before it was sent, the plant only processed 51% of its waste diversion target and each of the smoke tube boilers on all three lines “failed twice in commissioning”.

The documents also reveals the lines could not all be operated together as they would  overheat. The continuous emissions monitoring system (CEMS) also suffered overheating, meaning the “facility cannot lawfully operate if CEMS is not operational”.

Other issues included the incineration hall’s ambient temperature causing “an unsafe working environment”, the shotball system for cleaning boiler tubes was “unreliable” and the lines had “numerous valve faults”.

Numerous safety issues were also revealed in the documents:

  • Firewalls not completed or certified to allow insurability and compliance with fire protection plan

  • Roller doors not safe to operate due to failed components and design defects

  • Recycling baler not fastening bales correctly leading to safety issues

  • Insufficient documentation to operate the plant safely

  • No final health and safety file

  • Electrical safety – junction boxes not earthed, inadequate labelling.

The plant’s Kone cranes also had “numerous faults causing unreliable service”, there were issues with access for maintenance, instrumentation not recording data due to being set to simulation mode and alarms were “incorrectly set and inhibited”.

Odours at the facility also led to non-compliance with the plant’s environmental permit and prevented the use of onsite offices on welfare grounds. A bio-filter was also “not preventing odour emissions”, according to the documents.

Other issues listed in the documentsinclude: 

  • Licence expired on optical sorters

  • Education centre sprinkler system not installed

  • Leachate (liquids from waste) not draining from waste pit

  • Corrosion of structural steel in the RDF pit

While the site is still not operational, the councils behind it have previously told ENDS they remain committed to bringing the plant into operation.

A spokesperson for Derbyshire County Council and Derby City Council said: “This is an extremely complex project. It was always expected that there would be defects, as at the time of the contract termination, RRS handed over  a facility that was not operational. 

“Renewi was appointed by the councils following the termination of the contract with RRS to secure the site, carry out a deep clean of the facility, and to work to determine its condition and capability. This detailed investigation work will help to understand the current condition and identify any issues which need to be addressed. 

“The outcome of the work will also inform the council’s negotiations with financiers to pay an estimated fair value for the facility, this is the value of the plant, taking into account all of the potential costs of rectifying ongoing issues at the facility, and the costs of providing the services to meet the agreed contract standards. 

“Investigatory work is ongoing, and once completed, the councils will await findings of the surveys before considering its future use.”

Read the full documents here.

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