H4 Odour Impact Assessment
What It Is
An H4 Odour Impact Assessment is carried out in line with the Environment Agency’s H4 guidance document. It evaluates the potential impact of odours from industrial, waste, or commercial activities on nearby sensitive receptors, using recognised monitoring, modelling, and risk assessment methods. This assessment is often required for planning applications, Environmental Permit applications, or to address odour complaints.
Why It Matters — Risks Without It
- ❌ Planning refusal or Environmental Permit rejection
- ⚠️ Complaints escalating to enforcement action by the Environment Agency or local authority
- 📣 Damage to reputation with neighbours and communities
- 🧾 Costly delays and redesigns if odour issues are not managed upfront
What’s Measured
- Odour emissions from site sources (stacks, tanks, waste areas)
- Odour concentration (ouE/m³) through monitoring or sampling
- Meteorological conditions (wind, temperature, stability) for dispersion
- Predicted odour impact at nearby receptors
- Compliance against Environment Agency H4 benchmarks
How It Works
- Baseline Review: Collect site information, complaint history, and odour sources.
- Monitoring: Carry out on-site odour sampling and/or field surveys.
- Dispersion Modelling: Simulate odour dispersion using industry-standard models.
- Assessment: Compare results against H4 criteria for odour acceptability.
- Reporting: Produce a regulator-ready H4 assessment report with mitigation options.
Who It’s For
- 🏭 Industrial and waste operators applying for Environmental Permits
- 🏗️ Developers of odour-generating sites needing planning approval
- 🌍 Local authorities requiring robust odour impact evidence
- 🏢 Consultants managing environmental assessments
What You Get
- 📄 A regulator-approved H4 Odour Impact Assessment report
- 📊 Monitoring and modelling data benchmarked against H4 criteria
- 🧠 Expert recommendations to manage and mitigate odour impacts
- ✅ Evidence to support planning or permitting approval
Meet H4 standards with confidence: An Odour Impact Assessment provides the evidence regulators require to approve your project and manage odour risk.
