Some 50 such incidents have occurred in the region during that time, prompting warnings to farmers about the risks that farm pollution poses to the environment.
Silage effluent, for example, can be up to 200 times more toxic than untreated sewage if it gets into the waterways, insurance brokers Farmers & Mercantile highlighted, posing a threat to human and animal health.
The National Farmers’ Union (NFU) has previously stated that the longer term trend is that of a decline in serious pollution incidents from the agricultural industry, but Farmers & Mercantile said it was worried that “too many” farmers were still unaware of how destructive farm pollution can be to the environment, or the severe penalties they face if prosecuted.
Thomas Jones, on-farm account executive at the insurance brokers, said: “What many farmers don’t realise is that the latest sentencing guidelines mean they could be slapped with unlimited fines, or up to five years in prison, if found responsible for a pollution breach.
“Couple this with the fact that the Environment Agency are pushing for farmers who damage the environment to lose their government grants, and you have a situation which many farmers simply could not recover from.
“In summary, farmers’ businesses are being put in serious jeopardy because of carelessness. This is not a risk any farmer should be willing to take.”
Mr Jones warned that while insurance may cover the cost of any clean-ups, it is not available to cover the cost of substantial fines imposed if farmers fail comply with the law.
“Agriculture remains one of the biggest sources of pollution incidents, with the Environment Agency branding it ‘a slow-motion environmental catastrophe’,” he said.
“This is unsurprising, considering farmers are responsible for three quarters of the land in England, but much can be done to mitigate the risks.
“First of all, farmers should ensure their knowledge of environmental legislation is up-to-date and that they closely follow guidance from the Environmental Agency.
“Risk assessments should be conducted, such as identifying low-lying areas and waterways vulnerable to effluent run-off, and checks should be routinely carried out, from ensuring silage clamps and slurry containers are sound and secure to examining nearby waterways for signs of pollution.
“Adverse weather should be also taken into account, as heavy rainfall can increase the chance of toxic run-off. Contingency plans should be put in place, in preparation for every eventuality, and all workers should be made aware of these.”
Mr Jones said that if there is a pollution incident, suspected or confirmed, the Environment Agency should be contacted immediately, followed by the insurance company.
“It is worth bearing in mind that, as part of its crackdown on offenders, the Environment Agency is calling for incentives to be introduced for farmers who maintain a good environmental track record,” Mr Jones added.
“So, prevention not only provides peace of mind but may in the future reap benefits, if the Environment Agency realises its objectives to protect the environment for future generations.”
The Environment Agency’s Sustainable Business Report provides an annual assessment of the performance of businesses it regulates in England.
The NFU this week reiterated that farmers take their environmental responsibilities seriously and it has previously pointed out that a longer term decline in serious pollution incidents is down to a number of factors including the take-up of advice, the implementation of good practice and investment in storage capacity and machinery.
Yearly fluctuations in pollution incidents are unavoidable due to factors outside of farmers’ control, the union has said.
The union underlined the role that farming is playing in protecting and enhancing the environment at a conference attended by politicians and civil servants in London this week.
NFU president Minette Batters said: “Farmers want to play our part in rising to the Government’s wider challenge to be the first generation to leave the environment in a better condition than we found it.
“In order to do that, we need a balanced and honest appraisal of the current state of the farmed environment. Farmers take their environmental responsibilities very seriously and are passionate about the countryside.”