The Environment Agency has issued updated flood guidance for sites regulated under the Environmental Permitting Regulations and the Control of Major Accident Hazards (COMAH) Regulations.

The guidance advises operators of sites to start by obtaining a topographical survey of the site and the neighbouring land, including site levels which then need to be related to predicted flood levels in the area.

The Agency says that operators drawing up plans should consider the following issues:

• the impact of flood water inundating and/or floating plant and equipment
• the impact of loss of utilities on a short and long term basis
• the impact of the loss of safety critical equipment and other key components e.g. PLC’s, SCADA
• the ability to revert to manual operations taking into account hardware, operating procedures, competence and training
• the time needed to safely shut down operations and move personnel, polluting materials and stock

According to the Agency, a good plan will include steps to protect staff, safeguard hazardous processes and secure polluting material and stock. Operators should realistically be able to achieve these actions within the time available between receiving a flood warning and the site flooding.  The Guidance flags up the following specific measures which should be put in place:

• the allocation of flood response tasks to individuals who are trained for the role
• sources of flood warning, weather predictions and real-time river and sea levels
• appropriate trigger points - such as rainfall, river levels, flood warning - for specific action such as shutting down operations, isolating equipment, evacuating personnel
• links to asset registers and equipment status
• details of design, ownership and operation of relevant flood defences
• contact details and contractual arrangements for the supply of emergency resources e.g. pumps, power generators, clean-up equipment
• options for off-site recovery/remediation should loss of containment or pollution occur

The Environment Agency also says that flood plans should be exercised to build the competence of staff and ensure that actions are realistic given the likely time and on-site resources that will have available.

Key measures the guidance recommends putting in place to prevent flooding or mitigate its impacts include:

•  drainage systems with excess capacity and penstocks
•  sustainable drainage techniques such as retention ponds and soakaways
•  ground and platform raising or diversion channels
•  permanent or temporary flood defences
•  effective maintenance of drainage and flood management systems

The Agency also advises that operators should consider the location of safety critical plant such as control rooms, process control and instrumentation systems and emission abatement plant. They should also ensure that electricity (including on-site transformers and substations), gas, steam, heating, cooling and water supply systems are above predicted flood levels, are flood resilient or can be safely isolated or switched off before flooding.  The guidance suggests that as the loss of utilities may be for an extended period, operators should consider the installation of backup systems for critical equipment.

This guidance has been developed as part of a programme of work undertaken by the Chemicals and Downstream Oil Industries Forum as a collaborative venture formed to agree strategic areas for joint industry / trade union / regulator action aimed at delivering health, safety and environmental improvements with cross-sector benefits.

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