In the second and concluding part of this paper, Forensic Engineering Expert Professor Robert Jackson and Construction Lawyer Peter McHugh continue to discuss the risks to sustainability borne from the explosive consequences of energy-from-waste (EfW) facilities. This paper further highlights contentious disputes relating to design, construction, operation, environmental impact and personal injury, together with strategies for their avoidance.
Notwithstanding the commendable efforts displayed by energy sector players, as outlined in Part 1 of this article (March 2021), the renewables sector remains littered with projects where negligence and/or breach of contract has arisen. This can result from either the designer or the contractor failing to honour the contractual terms and/or failing to act with reasonable skill and care. The construction of an EfW plant can be a huge undertaking requiring the right team of experts to plan and build. Design-and-Build contracts place a heavy burden on the Contractor who will become liable for matters contractual, technical and operational. EfW plants are not simple production facilities but have great complexity akin to that of ‘mini power stations’ requiring careful design and construction by specialist contractors.
Increasingly, with advances in technology and innovation, new plants can be more cost effective, with enhanced safety and improved environmental benefits. But, failure to design and construct properly can lead to a magnitude of problems for the contractor and developer, as well as greater risks to plant operating staff and the wider general public. The construction of these projects remains ‘complex’ and is often confronted with disruption and disputes. Extra design costs and time delays can have a profound impact on the critical path of build activities and budget planning. Multiple sub-contractors are often required due to the interdisciplinary nature of waste projects and EfW plants are challenging and high risk for contractors, engineers, architects and designers alike. A common form of contract in this sector is the ‘Engineering, Procurement & Construction’ (EPC) contract which permits the plant owner to manage risk more effectively. The structure of the EPC allows both project owner & contractors to mutually benefit from this type of contractual agreement by assigning risks to ensure the designed output is achieved whilst administering responsibilities and liability.
For the procurement of a UK-based waste plant comprising an anaerobic digester, a contractor appointed a consulting engineer to develop and complete the design of the process engineering elements of the plant. The consulting engineer completed a detailed design but chose to provide a design which went beyond what was required in the ‘Delivery Plan’ thus adding to the contractor’s cost. It was held by the court that the designer was liable for the contractor’s increased costs. The court declared that a contract appointing a design consultant to develop and complete a waste treatment process required the consultant to comply with specific design and delivery obligations insofar as they accorded with the overriding objective to take reasonable skill and care. Under the contract, the engineer was prima facie liable for the cost consequences of any modifications to the design which did not comply with the specification or ‘Delivery Plan’; (MW High Tech Projects v Haase Environmental Consulting  EWHC 152 (TCC)). Designers of EfW plants are therefore in the firing line when it comes to faults in the design, and consequential losses due to increased operating costs, lost income generation from energy sales, and negligence leading to death or injury. EfW plants often rely on the generation of methane as an energy source, but the chemical properties of this gas make its handling inherently troublesome. This difficulty is perhaps well illustrated by reference to a case in the early 80’s.
In 1984, in order to satisfy an increased demand for local drinking water supplies, a new water supply project in Lancashire was commissioned by the then North West Water Authority (NWWA). This required the daily extraction of fresh water from the River Lune and its transfer,
by pumping, to the River Wyre. The Lune/Wyre Transfer Scheme comprised the construction of screen facilities at the water intake from the Lune, a pumping station, a transfer tunnel excavated through carboniferous limestone, a valve house in Abbeystead, and an outfall to the Wyre.
During the excavation of the tunnel, there had been a considerable in-flow of groundwater through the tunnel walls which continued to take place even after the rock tunnel had been lined with concrete. Also during excavation, traces of flammable natural gas were detected but these were deemed to be sufficiently low for the tunnel to be considered gas-free by normal tunnelling standards. Furthermore, the tunnel was designed to run full of water during pumping and to remain full with the pumps turned off. Consequently a feature of the design was that during standstill periods from pumping the tunnel would remain full of water to stop the ingress of groundwater and any gases emanating from the ground. The conditions of contract required the concentration of flammable contaminants to be kept below 10% of their lower explosive limit and there was no concern at the design stage regarding flammable gases being encountered during tunnelling.
On 23rd May a group of 44 visitors, comprising 36 residents of the local village of St. Michael’s-on-Wyre and 8 employees of NWWA, assembled inside the underground valve house set into the hillside at the outfall end of the scheme to attend a public presentation. This was to demonstrate the operation of the pumping station but when the pumps were started the pumped water travelled up the tunnel and in so doing displaced flammable gas that had accumulated in the tunnel from the ground. The gas was pushed into the valve house where it ignited causing an explosion that completely destroyed the valve house causing 16 deaths. No one escaped without injury, 8 were killed instantly by the explosion, with another 8 people, including an 11-year-old child and his mother, subsequently dying from their injuries in hospital. Every member of the visiting party was either killed or injured, with many suffering from severe burns.
The flammable gas was later identified as methane and its source, determined through geological and seismic surveys, was found to be coal seams located at a depth of 1.2km beneath the tunnel. The gas had collected over millions of years in a natural limestone reservoir from which it seeped towards the ground surface through a complex network of geological faults. The excavation of the tunnel had subsequently intersected these faults and allowed the gas to seep into the tunnel through its concrete lining. The cause of ignition has never been determined.
The Abbeystead disaster is an example of the responsibility on the design team to consider all possibilities including the presence of methane, and investigations later found that the possibility of a methane-rich environment had not been recognised. The fact that large quantities of methane might be dissolved in groundwater and subsequently released into the atmosphere within the tunnel was not considered by those involved with the design/operation of the system.
In 1987, at Lancaster High Court, the consulting engineers were found to be 55% liable in negligence for failing to exercise “reasonable care” in assessing the risk of methane. NWWA was found to be 30% to blame for failing to ensure the plant was safe for visitors and employees by testing for methane, and the contractor who constructed the works was found 15% liable for failing to carry out systematic tests for methane. All three parties appealed and a case was brought by the victims which went to the Court of Appeal. In the case (Eckersley and others v Binnie and others  18 CON LR 44, CA) negligence claims were brought by the survivors and relatives of the deceased against those responsible for the design, construction and operation of the works. Bingham L J stated when referring to the first defendants, the consulting engineers, that: “the original trial judge was entitled to find on the evidence that there was a risk of methane being present which should be taken into account in the design………..”.
The court of appeal held when considering the duties of care owed by each of the three defendants that in relation to the design stage, the consulting engineers who were the first defendant are expected to exercise the skill of a reasonable competent engineer specialising in the field of construction. The court held that in the circumstances, a reasonably competent engineer specialising in the design of water systems ought to have detected a risk of methane being present in the aqueduct. The explosion was therefore reasonably foreseeable.
The consulting engineers were held to be negligent in failing to consider the possibility that methane may be present when designing the aqueduct. The second defendants, the contractor, the court found was in breach of its contractual duty to test for methane, but this did not give rise to breach of any duty of care to the plaintiffs and the third defendants, the local authority, the court held that the evidence did not disclose any actionable negligence on its part. So, ultimately the consulting engineers were found solely liable. Leave to appeal to the House of Lords was refused and in February 1989 most of the injured survivors and relatives of those who died accepted out-of-court settlements from the consulting engineers.
In conclusion, sustainable development can be defined as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’. Whilst this definition is commendable, it is something of an oxymoron in that we have little or no insight into anything more than the very basic needs of future generations. Moreover, this article clearly highlights the imperative of understanding the environmental impacts of the past on present and future infrastructure development and if calamities are to be avoided then there is a need to recognise that ‘conjecture is not expert opinion’ and ‘hope is not a credible tactic’.
Professor Robert Jackson
Chartered Civil Engineer, Accredited Mediator for Civil & Commercial Disputes, Law Society Checked Expert, Forensic Engineering Expert in Water, Energy, Waste, Construction & the Environment.
JACKSON Consulting. M: 07976 361716; E: email@example.com.
Solicitor & Partner, Chartered Arbitrator & Accredited Mediator, Specialist in Construction Dispute Resolution.
Clarke Willmott Solicitors. T: 0345 209 1069; M: 07825 435981; E: firstname.lastname@example.org.