The Environment Agency (EA) is being taken to the High Court over claims it has failed to protect the River Wye from agricultural pollution.
River Action said the EA is dumping destructive amounts of nutrients from organic fertilizer into the river.
It is estimated that around 20 million chickens are reared in the Wye catchment at any one time, around 25% of UK poultry production.
The EA said it is “working hard” and taking action to restore the area.
A large amount of organic fertilizer has been spread across the country to encourage the rapid growth of the poultry industry near the river, which has led to a significant increase in soil phosphorus levels.
When the phosphorus is washed into the river by rainwater, it causes persistent algal blooms that suffocate plants and animals by sucking up all the oxygen and turning the water an opaque green.
River Action, which has sought judicial review against the EA, said that despite the Wye’s designation as a Special Area of Conservation, algal blooms have destroyed 90% of the river’s ranunculus, a family of aquatic plants.
In June 2020, an unprecedented algal bloom stretched more than 140 miles, almost the entire length of the river, it said.
A Lancaster University study published in May 2022 found that 60 to 70% of the river’s phosphorus now comes from agriculture and 3,000 tonnes of that enters the river each year, accumulating at a national average rate of nearly 3. (17 kg ) accumulating per hectare is just over 1. (7kg) per hectare.
Charles Watson, Chairman and Founder of River Action, said: “The severe ecological collapse of the legendary River Wye is one of the greatest environmental scandals of our time.
“The sickening tragedy is that this could have been seriously mitigated if the EA had enforced existing environmental regulations to prevent the overspreading of animal waste on land that was already oversaturated with nutrients.
“The irony is that the same government that instituted these regulations is giving the EA explicit instructions not to enforce them. This unlawful behavior by EA must stop now.”
Legal guidance from the Department for Environment, Food and Rural Affairs (Defra), where the EA operates, states that land managers should avoid applying manure during a crop rotation that raises soil phosphorus above a certain level, unless , this is not reasonably practicable or they have taken all appropriate precautions to prevent diffuse pollution from agriculture.
River Action said because crop rotations take place over multiple years, this approach does not protect the river and accused the EA of following the guidelines “slavely” at the expense of enforcing rules to protect the river.
The EA failed to apply agricultural rules to water, which prohibit the application of “organic fertilizer or man-made fertilizer” to farmland in a way that would increase nutrient levels beyond what “is needed by the crop and the soil.” “.
The charity also said the EA violated habitat regulations by failing to apply rules to meet its requirements.
Ricardo Gama, an environmental advocate representing River Action through Leigh Day law firm, said: “The Water Farming Rules were introduced in 2018 to specifically address the problem of agricultural pollution in rivers such as the Wye.
“But from documents we’ve seen, it’s clear that the EA is applying the rules in a way that is inconsistent with their own interpretation of how the rules work.
“This means manure – essentially an industrial waste product from meat and dairy production – can flow into our waterways with impunity.
“Our client hopes that this assertion will force the EA to reconsider their approach and start applying the rules properly.”
The EA said it is working hard to restore the health and environmental status of the River Wye – including through increased monitoring and increased farm visits, focusing on high-risk sites and previously non-compliant businesses.
It added: “Last year we received additional funding to carry out more inspections and since 01.01.
“The Farming Rules for Water is one of several regulations we are using as part of our consultative regulatory approach with farmers to protect water quality and nature.
“If we identify pollution or a significant risk of pollution, we will not hesitate to take further action – as evidenced by the enforcement actions taken against 140 farms this fiscal year.”