COMAH

Supporting Upper & Lower Tier Sites Across the UK

COMAH Compliance, Risk Management & Safety

Arthian delivers multidisciplinary support for sites regulated under the Control of Major Accident Hazards (COMAH) Regulations 2015. We help operators identify major accident hazards, assess environmental and human risk, and implement control measures that meet regulatory expectations.

Our clients include Upper and Lower Tier establishments across:

Chemicals, fuels and bulk liquids
Distilling and drinks manufacturing
Energy from waste and renewables
Pharmaceuticals and food production
Infrastructure, utilities and industrial estates

Our COMAH Services

Our COMAH services include:

General COMAH Consultancy Services

Containment & Infrastructure Modelling

COMAH Training & Safety Culture

General COMAH Consultancy Services

We offer clients a range of COMAH services, including:

COMAH Safety Report preparation and 5-year reviews
Major Accident Prevention Policy (MAPP) development
Environmental Risk Assessments (ERA) aligned with CDOIF
Occupied Building Risk Assessments (OBRA)
Quantitative Risk Assessments (QRA) and consequence modelling
Bund capacity and containment strategy assessments
Catastrophic tank failure modelling and bund overtopping analysis
COMAH training and awareness programmes
Hazardous Substance Consent and permitting support
ALARP justification and cost-benefit analysis
Predictive Climate Risk Assessment (PCRA) for future resilience

Containment & Infrastructure Modelling

We provide advanced modelling of containment systems to support COMAH compliance:

Bund permeability testing and integrity surveys
Secondary and tertiary containment strategy development
Firewater runoff and overland dispersion modelling
Below-ground oil migration and receptor risk analysis
Structural appraisal of bund walls and tank foundations
Integration with CIRIA C736 and COMAH containment policy

COMAH Training & Safety Culture

Our training programmes build competence across high-hazard sites:

COMAH awareness and regulatory duties
Safety Management Systems and ALARP principles
Emergency planning and response
Integration with DSEAR, OBRA and ERA

General COMAH Consultancy Services

We offer clients a range of COMAH services, including:

COMAH Safety Report preparation and 5-year reviews
Major Accident Prevention Policy (MAPP) development
Environmental Risk Assessments (ERA) aligned with CDOIF
Occupied Building Risk Assessments (OBRA)
Quantitative Risk Assessments (QRA) and consequence modelling
Bund capacity and containment strategy assessments
Catastrophic tank failure modelling and bund overtopping analysis
COMAH training and awareness programmes
Hazardous Substance Consent and permitting support
ALARP justification and cost-benefit analysis
Predictive Climate Risk Assessment (PCRA) for future resilience

Containment & Infrastructure Modelling

We provide advanced modelling of containment systems to support COMAH compliance:

Bund permeability testing and integrity surveys
Secondary and tertiary containment strategy development
Firewater runoff and overland dispersion modelling
Below-ground oil migration and receptor risk analysis
Structural appraisal of bund walls and tank foundations
Integration with CIRIA C736 and COMAH containment policy

COMAH Training & Safety Culture

Our training programmes build competence across high-hazard sites:

COMAH awareness and regulatory duties
Safety Management Systems and ALARP principles
Emergency planning and response
Integration with DSEAR, OBRA and ERA

Frequently Asked Questions

What is COMAH?

COMAH stands for Control of Major Accident Hazards. It’s a UK regulation that applies to sites storing or handling dangerous substances above defined thresholds.

What’s the difference between Upper and Lower Tier sites?

Upper Tier sites must submit a full COMAH Safety Report and emergency plan. Lower Tier sites must prepare a MAPP and demonstrate risk control measures.

Do I need an Environmental Risk Assessment?

Yes—COMAH sites must assess environmental risks using CDOIF guidance, including MATTE screening and source-pathway-receptor analysis.

Can you help with bund compliance and containment strategy?

Absolutely. We assess bund capacity, permeability, and structural integrity, and model containment scenarios aligned with COMAH containment policy.

Focused COMAH Services

Below are our COMAH services. For more detailed support, visit our focused service pages.

Bund & Containment Solutions

Bund & Containment Inspections and Solutions

Environmental Risk Assessment

Protecting the Environment from Major Accidents

Why Choose Arthian for COMAH Consultancy?

Our Understanding

Deep understanding of planning, infrastructure, and environmental interfaces.

Our Experience

National experience with regional insight and regulatory familiarity.

Integration

Fully integrated with geotechnical, hydrological, and ecological disciplines.

Results Driven

Commitment to technical rigour, clear communication, and long-term outcomes.

Our Latest Projects

View All Projects

Energy Engineering

Rushcliffe Borough Council Heat Decarbonisation Plans

Development of heat decarbonisation plan to support the Council's aim to make services carbon neutral by 2030

Energy Engineering

London Borough of Islington Heat Decarbonisation Plans

Development of 31 comprehensive Site Heat Decarbonisation Plans via Low Carbon Skills Fund (LCSF) Phase 5 funding

Civil Engineering Civil Engineering Design Temporary Works

MORAY WEST CIVIL ENGINEERING DESIGN

Onshore Civil Engineering Design for Transmission & Distribution

Get in Touch

We’d love to hear from you – whether you have a question, a project in mind, want to explore job opportunities, or just want to say hello.

Services

Services

Environment

Engineering

Planning

Safety

Net Zero & Decarbonisation

Sustainability Consulting

COMAH

COMAH Compliance, Risk Management & Safety

Our COMAH Services

General COMAH Consultancy Services

Containment & Infrastructure Modelling

COMAH Training & Safety Culture

General COMAH Consultancy Services

Containment & Infrastructure Modelling

COMAH Training & Safety Culture

Frequently Asked Questions

What is COMAH?

What’s the difference between Upper and Lower Tier sites?

Do I need an Environmental Risk Assessment?

Can you help with bund compliance and containment strategy?

Focused COMAH Services

Bund & Containment Solutions

Environmental Risk Assessment

Why Choose Arthian for COMAH Consultancy?

Our Understanding

Our Experience

Integration

Results Driven

Our Latest Projects

Rushcliffe Borough Council Heat Decarbonisation Plans

London Borough of Islington Heat Decarbonisation Plans

MORAY WEST CIVIL ENGINEERING DESIGN

Get in Touch