Agricultural pollution

Fertilisers, pesticides, and manure are a key part of food production, but their overuse and mismanagement results in these chemicals entering our rivers. Primarily, chemical pollution occurs through the process of surface run-off during excess rainfall, where pollutant-rich soils wash into rivers and waterways, introducing excessive nutrients that disrupt river ecosystems.

70% of nitrogen and 25% of phosphorus in UK waters can be attributed to attributed to agricultural runoff.

The intensification of farming, especially in the dairy sector, has led to a surge in manure and slurry production meaning a greater need for high-quality storage units. However, slurry storage units are costly to install and maintain, making them unaffordable for many farmers. As a result, many slurry storage units are faulty, and leach high-nutrient slurry and manure onto the land and into our waterways. In other cases, farmers opt for cheaper, environmentally harmful alternatives like spreading slurry on fields, entering our rivers through surface run-off. Read our Dairy Report for more information.

Damaged soils and weakened riverbanks are more vulnerable as climate change causes more intense and frequent rainfall, accelerating soil erosion and sediment runoff, which impacts water quality and soil stability. Additionally, increasingly frequent hot, dry periods bake the soil, preventing rain from being absorbed.

Policy and regulatory failures have exacerbated this issue, with insufficient support for farmers to improve environmental performance and inadequate enforcement of laws to prevent river degradation.

The current policy framework for regulating the relevant agricultural practices is outlined in the Farming Rules for Water (2018). These rules seek to prevent agricultural pollution of rivers, by regulating fertiliser and pesticide use, livestock management, and slurry storage.

Yet, these rules fall short in their protection for rivers and are poorly enforced. Analysis revealed that farmers can expect to receive an inspection from the regulator just once every 263 years, and despite the recruitment in 2022 of 50 new agriculture regulatory inspection officers, the regularity of inspections increases to only once every 50 years.

Even then, the government’s approach is often to ‘advise’ rather than enforce the law.

A broader issue lies in the supply chain, which demands cheap produce from farmers but fails to pay for the true cost of production, particularly its environmental impact. As a result, the public shoulders the burden—both through environmental damage and the taxpayer-funded costs of the ELMS. Both consumers and the supermarkets must take more financial and environmental responsibility for the pollution caused by agricultural practices.

High quantities of phosphates and nitrates in surface run-off disturb the ecological balance of the river, instigating the process of eutrophication. Eutrophication occurs when excessive nutrients enter a waterway, stimulating algae growth. These spurts of algae growth are known as ‘algal blooms’. The algae growth blocks sunlight from entering the water, disrupting the process of photosynthesis and starving the river of oxygen. This creates ecological ‘dead zones’ in the river, destroying habitats for important invertebrates and fish larvae. River Action’s campaign on the River Wye highlighted the severe impacts of nutrient run off, emphasising the need for stricter regulation.

Pictured: Algal Bloom, Lough Neagh, Northern Ireland.

Arable farmland across England and Wales shows significant signs of erosion, with already damaged soils more likely to be swept away. This soil ends up in our rivers as sediment, reducing water quality and damaging habitats by coating riverbeds in a layer of silt and suffocating life beneath. Erosion also reduces soil health, making farming more challenging and often leading to the increased use of fertilisers, resulting in a cycle of environmental degradation and harmful run-off into our rivers.

Additionally, the longer, drier summers as a result of climate change harden soils, reducing their ability to absorb rain. This leads to more frequent flash flooding events, which can have catastrophic consequences, washing away surface soil and nutrient-rich fertilisers into our rivers.

Improper slurry management and nutrient runoff drive up water treatment costs for water companies tasked with removing these excess nutrients, bacteria, and sediment. The financial burden of these enhanced treatment processes often falls on consumers. Water companies may pass increased operational costs onto households through higher water bills. A study by the Parliamentary Office of Science and Technology (POST) highlights that preventing water pollution at source can have a cost-benefit ratio as high as 1:65, underscoring the economic advantages of proactive measures.

Agricultural pollution often remains unchecked and unaddressed due to weak regulatory enforcement and inadequate penalties. We need a system that issues penalties to the farms that pollute our rivers, whilst also providing support and expert guidance.

To protect and restore our rivers farmers need greater financial incentives, fairer prices, and clearer guidance. Agricultural subsidy schemes, such as the Environmental Land Management Schemes (ELMS), must be simplified and better funded, so that they are accessible to all farmers and have higher payments for actions that reduce agricultural pollution.

Supermarkets and food companies must also ensure fair pricing that enables farmers to invest in sustainable practices. The government must ensure supermarkets adopt robust, independent, labelling standards that accurately reflect environmental impacts.

Nutrient trading has also emerged as a solution for farmers to mitigate nutrient pollution. It involves changing land use from commercial agricultural land to a nature-based use, such as agro-forestry or grasslands, earning credits for the reduction in nutrient discharge achieved. These credits can then be traded with other farmers and interested parties, such as developers, incentivising sustainable farming practices.

Strategies that use natural processes to tackle water pollution must become a top priority in government decision making.

There is overwhelming evidence to suggest farming and nature can co-exist in a mutually beneficial relationship. Moreover, it is more efficient, cost-effective, and environmentally friendly to prevent pollution entering our rivers through water sensitive land management than rely on expensive artificial interventions such as filtration equipment.

This often involves regenerative agricultural practices, such as integrated pest management and rotational grazing.

River buffers are another effective nature based solution – at which agriculture ends and natural vegetation begins. These vegetated areas, often woodland and shrubs, trap sediments, nutrients, and pollutants, acting as a buffer that improves water quality and reduces erosion. They also provide much needed wildlife habitats and support the biodiversity of river ecosystems.

See this detailed proposal The Beaver Trust submitted to the government here.