Environmental risk assessment and control
This domain tests how you identify environmental hazards, judge how severe and likely the resulting harm is, and choose controls that are proportionate. Questions typically involve source–pathway–receptor analysis, scoring matrices, the hierarchy of control, best available techniques (BAT), and emergency preparedness under ISO 14001 clause 8.2.
Start with source, pathway, receptor
Harm only occurs when all three connect. A 20,000-litre fuel tank is a source; a cracked bund and permeable ground form the pathway; a borehole 60 m away is the receptor. Remove any link - bunding, impermeable surfacing, relocating the borehole - and risk falls. Risk is normally scored as likelihood × consequence, so state both and justify each score in the register.
Controls, in order
- Eliminate - remove the process or substance.
- Substitute - e.g. replace a chlorinated solvent with an aqueous cleaner.
- Engineering - secondary containment, abatement, closed-loop transfer, interceptor.
- Administrative - procedures, inspection regimes, training, permits to work.
- PPE - protects the worker, rarely the environment, so it is not a primary environmental control.
Check for cross-media transfer: a scrubber turning an air emission into a liquid effluent has not solved the problem unless the effluent is treated.
Worked example
A 205-litre drum of degreaser sits on a loading bay 8 m from a surface-water drain. Uncontrolled: likelihood 4 (routine handling, no bund) × consequence 4 (toxic to aquatic life, direct route to the drain) = 16, high. Controls: self-bunded pallet, relocation under cover, drain seals, spill kit, trained responders. Likelihood falls to 2; consequence stays 4 because volume and toxicity are unchanged → residual 8, medium: accept, monitor, review if throughput rises.
Traps
- Claiming a control reduces consequence when it only reduces likelihood.
- Ignoring the pathway, then missing that a yard drain gives a direct route to a river.
- Treating PPE or "staff awareness" as sufficient for a significant aspect.
- Forgetting to reassess after process change, new chemicals or a spill incident.