Leaks from biogas plants lead to five-figure fines
Trinity Hall Biogas Ltd has been made to pay over £20,000 after poor site management led to water pollution at the site of an anaerobic digestion (AD) plant in Hockliffe, Bedfordshire.
Luton Magistrates’ Court fined the company £10,000 and ordered it to pay £10,423 in EA costs after overflows from the plant in December 2013 and April 2014 led to the pollution of three kilometres of local watercourses.
Trinity Hall Biogas leased the land of Trinity Hall Farm to run the AD plant, which was operated by Scott and Scott, a farm management company that offers AD services. Warren Scott, the controlling partner of Scott and Scott, had already accepted a caution at a previous hearing.
Wendy Foster, who was prosecuting for the EA, told the court on 15 June that Scott had reported an overflow of effluent from a storage container at Trinity Hall Farm. The storage container held liquid that had leached from a maize heap stored as biofuel for the AD plant. The tank had not been checked and had overflowed, with the effluent entering a nearby ditch that led into the Ouzel Brook.
Foster also said silage regulations had been breached as bags of wrapped biofuel, owned by the company, were stored in a field in rows, the ends of which were within 10 metres of the ditch where the effluent had been found.
Samples of bacterial growth were taken from the watercourse and indicated that there was ‘ongoing chronic pollution’.
Mismanagement, not bad luck
The EA returned to the site four months after its initial visit to retest the water quality of Ouzel Brook and found ammonia levels were 10 times higher than normally found in similar watercourses. Foster said: “Any concentration in excess of five milligrammes (mg) per litre is likely to have a toxic effect on aquatic life.” Measurements at Ouzel Brook revealed ammonia levels of 10mg per litre.
During the return visit to the farm, the storage container was found to be close to overflowing and a mud bank had been cleared to create a direct path for the effluent to flow down to the watercourse. The pump was leaking in several places and the effluent was running into a nearby ditch.
Trinity Hall Biogas told EA investigators that Scott and Scott was the day-to-day operator of the AD plant and was only responsible for emptying the tank if there was an agreement with the company for them to do so. At the time of the offences, no such agreements had been detailed, which the EA says was an oversight by the company.
Foster said that rather than being an isolated incident, the event had occurred due to poor management of the site: “The offences arose out of negligence of the defendant company. The repeated incidents of pollution and failures to comply with regulations are indicative of inadequate systems and monitoring rather than an isolated incident.”
Trinity Hall Biogas Ltd said it had reported the incident and has now put in place infrastructure to prevent further offences.
The district judge hearing the case said: “Self-reporting the incident was a substantial mitigating factor – the pollutions impacted upon three kilometres of the watercourse. It is incredulous that there was no system in place to empty the tank.”
Following the hearing EA officer Kat Wynn said that regulations are there to be followed and guidance can be found on the government website. She added: “Given that the tank was close to nearby ditches, it was reasonably foreseeable that any overflow would cause pollution. Operators of businesses that store polluting effluents should have rigorous procedures in place to minimise the risk of an overflow or leak occurring.”
Trinity Hall Biogas Ltd pleaded guilty to two counts of causing a poisonous, noxious or polluting matter to enter inland freshwaters without being authorised by an environmental permit and two counts of failing to ensure that silage was placed at least 10 metres from inland freshwater.
Fines ensue after ‘negligent pollution’ of River Dalch, Devon
The two companies were handed the fine at Exeter Magistrates’ Court on 23 June after being found guilty of polluting two and a half kilometres of the River Dalch.
After suspected pollution in the River Dalch was reported on 11 February 2015 the EA carried out an investigation and found that the source of the pollution was liquid silage effluent from Menchine Farm, where the biogas plant was being operated. The plant turns agricultural waste and energy crops from nearby farms into gas through AD.
The effects of the pollution were substantial, with the Environment Officer who visited the site finding 100 per cent sewage fungus coverage for one kilometre from the discharge point and significant sewage fungus growth impacting a total of two and a half kilometres of the River Dalch.
Richard Tugwell, the Environment Officer investigating for the EA, said: “Silage effluent has a severely polluting effect – it is 100 times more polluting than raw sewage. Starving the river of oxygen has led to a significant adverse effect on water quality, animal health and flora.
“We are satisfied with the outcome and pleased the courts have taken this matter seriously.”