A flood, pollution spill or fire incident are the 'what if' scenarios no business ever wants to contemplate. David Cole explains how to manage the risk and demonstrate regulatory compliance.
16 July 2015 | By David Cole
Flooding and water pollution are inextricably linked and planning for protection is critical for any site, facilities or environmental manager.
The impact of a pollution spill or flood is often badly underestimated - as is the commercial and environmental damage they can cause.
The only acceptable kind of pollution risk is one that a business can demonstrate it has taken adequate measures to protect against. No business can afford to continue in the belief that it could never be subject to a serious water pollution incident.
Pollution containment is particularly critical for sites operating under the Control of Major Accidents and Hazards (COMAH) 2015 or Environmental Permitting (England and Wales) Regulations (EPR) 2010. It should also be integral to any compliant Environmental Management System (EMS) - or for those companies working to IS0 14001.
The introduction of the revised COMAH regulations on 1st June has provided a timely opportunity for regulated sites to fully review their risks and ensure both their business and the surrounding environment are fully protected.
As government funding is cut back, environmental authorities are being forced to relinquish their advisory role and are increasingly enforcing regulations through prosecution. Even for those operators who are already familiar with their responsibilities, a comprehensive review could be highly advisable.
Causes of pollution
Sites that store or use hazardous or polluting substances need to take steps to ensure that these do not escape into the environment. Even for sites that would not obviously be at risk, flooding or firefighting water could still be a concern - a fire at a waste recycling facility could lead to environmental pollution if firefighting water is not contained on site.
For most sites fitting a containment valve is the conventional way to contain polluted water by blocking underground drainage. For some sites additional flood protection measures such as bunds and underground storage tanks are also necessary to hold back water.
But all too often companies retrofit containment valves without actually having any technical evidence to demonstrate how it will hold water pollution safely on site in an emergency. Without this knowledge, can companies really understand how a pollution containment system will operate in an emergency?
What will happen if a pollution spill is combined with a source of flow into the below-ground drainage system such as fire water or rainfall? When the drainage system is overloaded, the backed-up flows could simply bypass the containment device either by other below-ground flow paths or as overland flood water.
A robust flood risk assessment provided by suitably qualified experts will identify all sources of flood risk, along with potential flow paths into and out of a site. A Hazard and Operability (HAZOP) study may also be an appropriate methodology to provide an evidence-based understanding of the combined water pollution and flood risks.
As part of this process, using hydraulic modelling can be invaluable. It can be used to accurately map the surface water and pollution pathways on and off a site as well as assessing and validating the effectiveness of the drainage system design.
This specialist 2D modelling technique, developed by Hydro Consultancy's team, is an approach that requires a mix of flood risk and pollution containment expertise. It can provide an effective method to test the efficiency of pollution containment systems - and provide reliable evidence for regulators and EMS documentation.
Under planning guidelines the suitability of a new development is assessed using a system that compares flood-risk vulnerability against its compatibility with a flood zone. The National Planning Policy Framework states that for any "installations requiring hazardous substances consent" such as COMAH and EPR sites, their vulnerability classification would be "highly vulnerable".
This would place planning restrictions on such development because of flood risk in two of the three 'flood zone' classifications. But this applies only to new developments and many existing sites are unlikely to have been built to these guidelines. So when considering existing highly vulnerable sites it's a fair assumption that many are in a zone that is inappropriate to their vulnerability, and the residual risks are not fully understood.
An unexpected pollution incident is likely to land an unprepared operator with large fines and a substantial bill for remediation. Insurance cover may not be sufficient to pay for the clean-up costs in all but the most exceptional circumstances. In the worst cases a pollution conviction can even invoke custodial sentences for company directors.
Notwithstanding a company's regulatory obligations and noting that in most instances the 'polluter pays', the expectations of corporate social responsibility alone (especially for larger companies) make it good practice to show exemplary environmental compliance.
David Cole is water pollution manager at Hydro Consultancy