Highways Agency

• Traffic Incident Management Bulletin

March 2007

Environmental spillages can be a major issue for the Highways Agency and their Service Providers in their day to day management of the motorway and trunk road network. These spillages can occur as a result of road traffic accidents, items being disposed of within the network boundaries as well as items falling from vehicles travelling along the network. The key issue is that when such an incident/event occurs that there are robust processes in place to prevent more widespread environmental pollution, with a clear need to work with partnering organisations such as the Environment Agency, Fire & Rescue Services and Local Authorities.

An example of such an event is detailed below

At approximately 14:00 on Monday 4th April 2005, a 7.5t goods vehicle was on the M6 Junction 16 northbound sliproad when 4 Containers it was carrying, were shed onto the carriageway, each containing1000 litres of an unidentified liquid. The Cheshire Fire & Rescue Service attended and as the driver did not know what the load was and as there was no paperwork or markings on the vehicle, they placed a cordon around the scene until the material could be identified.

The spilt material was identified as emulsified kerosene and denoted as a marine pollutant that is harmful to any aquatic environment. Once identified and deemed as being safe to clear up the cleansing process commenced.

At 14:10 hours Atkins was notified about the spillage and the Environment Agency (EA) was informed and attended the scene.

The incident spanned the border between two Highways Agency areas (10 and 11) with Area 10 agreeing to manage the incident and carry out the clear up operation.

At approximately 16:30 hours Cheshire Fire & Rescue Service informed Atkins and AmeyMouchel staff that everything had been contained. It was interpreted from this that all of the material had remained on the carriageway and as a result the Environment Agency being on scene they were happy with the results of the clear up operation.

The scene clear up was carried out by Area 10’s specialist waste contractor, Mantank. Cheshire Fire & Rescue Service and Mantank’s Hazardous Materials (HazMat) trained staff discussed the hazards and how to safely remove the material.

At 18:15 the sliproad had been cleared and was re-opened and the incident was deemed closed at this point.

At 20:00 the Atkins Duty Engineer received a call from the Environment Agency regarding pollution of a watercourse approximately 1.5 miles from the incident scene. Initially this seemed unlikely to be connected as the watercourse was not the one that the known outfall went to. Following further evaluation by the Mantank Hazmat officer and the Duty Engineer at the scene it became clear that this pollution was connected to the earlier incident.

Later analysis demonstrated that approximately 2000 litres of the emulsified kerosene had entered the drainage system. Kerosene, like any oil product, would normally float on the surface of a watercourse making removal fairly straightforward using absorbent booms and mats. However, this incident involved an emulsion of kerosene with detergent, which was able to mix with the water, this turned Barthomley Brook into a milky white colour that smelt of turpentine.

To remedy this situation the only feasible solution was to pump out all the contaminated water and remove it for treatment. Barthomley Brook is small, however the flow is greater than could be pumped out so a dam had to be constructed.

At 21:30 the front edge of the pollution had been located and a site identified for abstraction, a site where the Brook crossed the A500. This site allowed good access to carry out the abstraction and as the pumping operation was going to require non stop movements of articulated vacuum tankers, good road access was critical.

At 00:01 the A500 westbound was closed to provide a safe working zone for the abstraction operation. This was implemented by Cheshire Police and reinforced by the ISU’s. Cheshire Police agreed to man the closure to release the ISU to the scene. Scene lighting was provided by the fire brigade and construction of a simple earth dam began. This was hand dug by all on site including the Environment Agency Officers.

At 04:00 it was apparent that the A500 would have to remain closed through morning peak traffic as the clean up process was still on going. The Highways Agency’s National Incident Liaison Officer (NILO) was informed to ensure that the media would publicise the closure on the morning news broadcasts.

At approximately 05:00 the dams were struggling to cope with the flow and the vacuum tankers were being delayed by congestion. The Duty Engineer deemed it necessary to call for mutual aid. Area 11 and Cheshire County Council were both called upon requesting resources. Area 11 supplied operatives, 70 sandbags and mobilised their environmental subcontractor. Cheshire County Council also provided operatives and a further 50 sandbags.

At 08:30 the dam was reinforced sufficiently to hold the flow and allow the vacuum tankers to abstract the remaining polluted water.

At 11:00 the main abstraction operation was complete with Mantank estimating that a total of 275,000 litres of contaminated water had been removed. The dams were removed and the contaminated material taken away to a licensed tip.

At 16:00 the dams were cleared and all equipment retrieved.

At 16:20 the A500 was reopened.

In total the clear up operation took 20 hours to remove over 130 times more liquid than was actually spilt.

The major lessons learnt during the cold incident debrief were:

• Having sufficient resilience in the Duty Engineer system was identified as an issue as protracted incidents such as this require Duty Engineer expertise for extended periods. As a result of this incident a more formal, robust back up system was put in place to make additional Duty Engineers available if required at short notice.
• A spill kit was deployed to the previously unknown outfall location. This information was shared with Area 11. All outfalls have now been plotted on the Atkins Area 10 Geographic Information System (GIS). 
• The importance of clear communication and ensuring everyone understands the meaning of certain phrases. i.e. The fire service definition of contained related to the scene being under control and the Highways Agency and Service Providers understand it to mean the spillage can not spread.
• Accurate and full drainage inventory information is critical when managing spillage incidents. This information really needs to be accessible out of hours.
• The diversion routes for this incident coped with the increased flows of traffic. The VMS were used on the M6 prior to the previous junction in both directions to allow drivers to divert early. This eased the traffic levels on the local routes.
• The benefits of having good relationships with your neighbours. Being able to call on Area 11 and Cheshire County Council enabled significant additional resource to be mobilised. Costs for this incident were all passed via AmeyMouchel and recharged to the haulier via the Green Claims process.
• The importance of having a knowledgeable specialist available at all times. Mantank provided expertise at the scene and were able to deploy the necessary resource at an early stage.