ENV/Water Pollution/TBT-ENV-016

Chemical Storage Near Watercourses

EnvironmentalWater PollutionChemical Storage Near Watercourses

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Chemical Storage Near Watercourses

Toolbox Talk Record

Ref: TBT-ENV-016  |  Issue: 1  |  Date: March 2026
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What?

  • Chemicals stored near rivers, streams, and ditches pose an immediate pollution risk if containment fails.
  • Construction chemicals include fuels, oils, paints, solvents, cement, and water treatment products.
  • A single litre of oil can contaminate one million litres of drinking water if it enters a watercourse.
  • The Environmental Permitting Regulations make it an offence to allow pollutants to enter controlled waters.
  • Secondary containment (bunding) must hold 110% of the largest container or 25% of the total volume stored.
  • Bunds must be impermeable, resistant to the stored chemicals, and regularly inspected for integrity.
  • Spill kits appropriate to the chemicals stored must be available immediately adjacent to the storage area.
  • Drainage from chemical storage areas must not connect to surface water drains or watercourses.
  • The Environment Agency can require clean-up, prosecute, and impose unlimited fines for water pollution.
  • PPG2 and subsequent Environment Agency guidance set the standards for above-ground oil and chemical storage.

Why?

Water pollutionChemical spills reaching watercourses kill fish, contaminate drinking water supplies, and destroy aquatic habitats.
Unlimited finesCausing pollution to controlled waters is a criminal offence with unlimited fines and potential imprisonment.
Irreversible damageChemical contamination of watercourses persists for years. Prevention through proper storage is the only effective approach.
Do Don't
  • Store all chemicals in bunded areas with 110% containment of the largest container.
  • Position chemical stores as far from watercourses as the site layout allows.
  • Use drip trays under containers, taps, and connection points to catch leaks.
  • Keep spill kits immediately available adjacent to all chemical storage locations.
  • Inspect bunds regularly for cracks, degradation, and accumulated rainwater.
  • Remove rainwater from bunds promptly but only after checking it is uncontaminated.
  • Ensure bund materials are compatible with and resistant to the chemicals stored.
  • Lock chemical stores to prevent unauthorised access and tampering.
  • Display safety data sheets for all chemicals stored at the storage location.
  • Report any spill immediately and deploy spill kit materials to contain it.
  • DON'T store chemicals within 10 metres of a watercourse without enhanced containment.
  • DON'T use bunds with cracks, holes, or degraded linings for chemical containment.
  • DON'T drain accumulated rainwater from bunds directly to surface water drains.
  • DON'T leave chemical containers open, leaking, or unsecured in storage areas.
  • DON'T connect chemical storage area drainage to surface water drains or ditches.
  • DON'T store incompatible chemicals in the same bund without separation measures.
  • DON'T delay spill response; deploy the spill kit immediately to prevent water entry.
  • DON'T overfill containers or leave them without secure caps and lids.
  • DON'T assume small drips and leaks are insignificant; they accumulate rapidly.
  • DON'T dispose of waste chemicals by pouring them onto the ground or into drains.

See also: Spill Kit Use and Deployment | Groundwater Contamination Prevention

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