Agricultural Spill Control — COSHH, EA and Farming Regulations

UK farms store and use a wide range of hazardous substances including diesel fuel, agricultural lubricants, pesticides, fertilisers, sheep dip compounds, veterinary medicines and cleaning chemicals, as well as managing silage effluent and slurry — agricultural liquids with extreme polluting potential. Agriculture has historically been one of the largest contributors to serious water pollution incidents in England and Wales, and the Environment Agency and Natural Resources Wales actively enforce farming regulations. This guide provides a comprehensive reference for farmers, farm managers, agronomists and environmental consultants on all aspects of agricultural spill control compliance.

The SSAFO Regulations 2010: The Agricultural Spill Control Baseline

The Water Resources (Control of Pollution) (Silage, Slurry and Agricultural Fuel Oil) (England) Regulations 2010 (SSAFO) are the primary agricultural environmental regulations governing liquid storage that poses water pollution risk. Similar regulations apply in Wales (Natural Resources Wales), Scotland (SEPA) and Northern Ireland (DAERA). SSAFO sets legally binding construction and capacity standards for three categories of agricultural storage:

Silage Effluent Storage

Silage effluent (the liquid that drains from grass silage during the first weeks of storage) has a Biochemical Oxygen Demand (BOD) of 30,000–80,000 mg/litre — 200 times more polluting than raw sewage. SSAFO requires that all silage stores constructed after 1991 have a base and walls constructed to prevent seepage, with capacity for all effluent arising from the first 90 days of storage. Effluent tanks must be sited at least 10 metres from any watercourse or land drain. Leaking silage stores are one of the most serious water pollution risks in UK agriculture.

Slurry Storage

Livestock slurry (a mixture of faeces, urine, bedding and dirty water) must be stored in facilities that prevent any seepage or overflow to watercourses. SSAFO requires slurry stores to have: impermeable base and walls, a minimum storage capacity of 4 months (in Nitrate Vulnerable Zones) or as otherwise required, with freeboard of at least 300 mm. Slurry spreading is also regulated under the Nitrates Regulations (applying in NVZs) to prevent pollution of water bodies with nitrogen.

Agricultural Fuel Oil Storage

Fixed agricultural fuel oil tanks above 1,500 litres capacity must have secondary containment (bund) with at least 110% of the tank volume. The bund must be impermeable, with no uncontrolled drainage outlet. Fill points must be positioned to prevent overspill reaching uncontained ground. This applies to diesel (gas oil/red diesel) and fuel oil used for heating farm buildings. Note: the 1,500-litre threshold for SSAFO is lower than the 200-litre threshold applicable to commercial and industrial premises — this is because farm tanks are typically in more environmentally sensitive locations near watercourses.

Pesticide Storage: Code of Practice Requirements

The storage and use of plant protection products (pesticides) on farms is governed by the Code of Practice for Using Plant Protection Products (England and Wales), updated under Regulation (EC) No 1107/2009 (retained in UK law) and the Plant Protection Products (Sustainable Use) Regulations 2012. Key storage requirements:

• Dedicated secure store: Pesticides must be stored in a dedicated, lockable store, separate from animal feed, food, and seeds. The store must be accessible only to trained, certificated users.
• Impermeable base and containment: The store floor must be impermeable and the store must have bunded containment to capture any leaks or spills — minimum 110% of the largest container.
• No drainage to watercourse: Drain outlets from the pesticide store must not lead to surface water or field drains. All spilled material and contaminated water must be collected and disposed of as hazardous waste.
• Fire protection: Where quantities exceed certain thresholds (check SDS for specific substances), fire separation or fire-rated construction may be required.
• Spill response: A spill kit appropriate to the pesticides stored must be located within or immediately adjacent to the store. Relevant PPE (per SDS) must be available at all times.
• Records: Records of pesticide stock, usage, disposal and any spill incidents must be maintained for inspection by FERA, EA or DEFRA inspectors.

The PA1/PA2 (or equivalent) certificate of competence is required for all persons applying pesticides (with limited exemptions). Pesticide storage and handling competence is increasingly assessed in farm assurance schemes.

Sheep Dip Disposal

Organophosphate (OP) sheep dip (e.g., diazinon-based) and synthetic pyrethroid dip (e.g., cypermethrin) are acutely toxic to aquatic invertebrates at parts per billion concentrations. They are classified as Priority Hazardous Substances under the Water Framework Directive. The regulatory requirements for sheep dip management are among the most stringent for any agricultural chemical:

• Containment: Dipping must be conducted on an impermeable concrete area with collection sump. No overland flow to field drains or watercourses.
• Licensing: Disposal of spent dip requires a waste exemption or permit from the EA. Options include: land spreading (if SEPA/EA approved and no risk of run-off), authorised waste contractor collection.
• EA prior consultation: Guidance strongly recommends contacting the EA before each dipping season to confirm the approved disposal method for the specific dip product used.
• Records: Records of dip used, volumes, dates, disposal route and contractor details must be maintained.
• PPE: OP compounds are absorbed through skin — operators must wear chemical-resistant gauntlets, waterproof coveralls and face protection per SDS requirements.

Fertiliser Storage and Nitrate Regulations

Manufactured fertilisers — particularly ammonium nitrate (AN) and compound NPK fertilisers — present both environmental and safety risks. Key regulatory requirements:

• Ammonium Nitrate (AN) above 28% N: Regulated under the Explosives Regulations 2014 and COMAH (Control of Major Accident Hazards) at higher quantities. Storage requires formal risk assessment and (at higher quantities) formal safety reports.
• Nitrate Vulnerable Zones (NVZs): Farms in NVZs must comply with the Nitrates Regulations (Nitrate Pollution Prevention Regulations 2015 in England) limiting nitrogen application rates, spreading periods, and storage requirements.
• Fertiliser stores: Must be positioned and constructed to prevent run-off to watercourses or field drains. AN fertiliser stores must meet requirements of current HSE/DEFRA guidance.
• Spill response for fertiliser: Solid AN fertiliser contaminating a watercourse causes aquatic oxygen depletion and algal blooms. Spills must be prevented from reaching drains; contaminated soil should be collected and spread at agronomic rates.

Agricultural Waste Exemptions

The Environmental Permitting (England and Wales) Regulations 2016 Waste Exemptions allow farmers to manage certain types of waste without an environmental permit. Relevant exemptions for spill waste management include:

• D7 exemption: Burning plant tissue on land (not relevant to chemical spill waste)
• U1 exemption: Use of waste on land (pesticide-contaminated soil may be managed under specific conditions)

Note: contaminated spill waste from pesticide or fuel spills is typically hazardous waste and cannot be managed under routine agricultural waste exemptions. It must be disposed of by a licensed hazardous waste contractor. Farmers should contact the EA for specific guidance on disposal options for their waste type.

EA Farm Inspection Priorities

The Environment Agency's Farming Rules for Water (The Reduction and Prevention of Agricultural Diffuse Pollution (England) Regulations 2018) and the Water Resources Act 1991 give EA officers broad powers to inspect farms and require improvements. EA Farm Inspection priorities include:

• Fuel storage compliance (SSAFO bunding, fill point containment, pipe integrity)
• Silage and slurry storage integrity (SSAFO compliance, structural condition)
• Pesticide store construction and containment
• Farmyard runoff management (hardstanding drainage, yard clean-up practices)
• Sheep dip management and disposal records
• Evidence of spill incidents (staining on concrete, dead vegetation near watercourses)

EA officers can serve Enforcement Notices, Remediation Notices and pursue prosecution for SSAFO breaches, water pollution offences and hazardous waste offences. The EA's Enforcement and Sanctions Policy means that repeat offenders or those causing serious pollution incidents face prosecution and unlimited fines.

Red Tractor Farm Assurance Requirements

Red Tractor Farm Assurance is the UK's largest farm assurance scheme, covering arable, combinable crops, fresh produce, beef & lamb, dairy, and pigs. All Red Tractor standards include environmental management requirements relevant to spill control. Red Tractor assessors check:

• Fuel tank bunding compliance (SSAFO requirements)
• Pesticide store construction and containment
• Chemical register including SDS availability
• Spill kit provision in high-risk areas (fuel storage, pesticide store)
• Documented spill response procedures
• Evidence that staff have been trained in chemical handling and spill response
• Records of any spill incidents and corrective actions taken

Non-conformances against environmental standards in Red Tractor audits must be closed out within defined timescales or the certificate is withheld. For farms supplying major UK retailers, Red Tractor certification is typically non-negotiable.

Farm Spill Kit Specification

Based on the range of hazardous substances present on a typical mixed farm, spill kits should be specified and located as follows:

• Fuel store / bulk tank area: 240-litre oil-only wheelie bin spill kit with sufficient capacity for the largest tank on site. Oil-only (white) absorbents that float on water for any drain or stream contamination.
• Pesticide store: 90-litre chemical spill kit with universal (grey) absorbents, acid/alkali test strips, chemical-resistant nitrile gloves, goggles, disposal bags.
• Farmyard general: 90-litre universal spill kit at central location for hydraulic oil, lubricants, animal medicines.
• Sheep dip area: Dedicated kit with chemical absorbents and PPE per dip product SDS — kept separate from general farm kit.

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Spill Control Products UK supplies agricultural spill kits, fuel tank bund systems and pesticide store containment products to farms across the UK. Contact our team for advice on SSAFO-compliant containment systems and Red Tractor compliance support.