Severe Fire

How to solve a problem like Leaping Goat Farm

Abstract:

Richfords Fire and Flood were contacted by XYZ loss adjusters to investigate a smell of oil in the kitchen of a Devonshire farmhouse.

It was found that heating oil had been spilled against an exterior cob wall of the building and an oil plume still affected this wall.

Using an innovative vapour extraction system Richfords Fire and Flood were able to remove the oil contamination avoiding the need to demolish significant portions of the property.

The occupiers where able to remain in the property during the extraction process, due to the careful design of the suction system. Therefore XYZ where pleased to avoid a lengthy alternative accommodation claim.

Following this process, oil vapours inside the property were reduced to below the accepted standard and the exterior wall of the property was re-painted.

Following this lengthy and challenging project that Richfords final invoice was on target at the amount estimated at the beginning of the project.

The Property:

Leaping Goat Farm is a small holding situated in Winkleigh, Devon. Approximately 20 miles North East of the city of Exeter. The property is not a working farm and there are no other business activities based on the premises.

The farm its self comprises of several buildings clustered together at the centre of the property. There are three small barns, on of which has been converted into modern living accommodation and the main farmhouse. The main house is a traditional Devonshire farmhouse of cob wall construction.

There is a small stream running alongside the main driveway leading to the farm buildings. This stream however branches off and does not flow near to the buildings.

The Situation:

Richfords fire and Flood where contacted by XYZ loss adjusters on the 17th June 2006 at 3:15pm.

The owners of the property had registered an insurance claim reporting a smell of oil in their kitchen.

Initial instructions were given to investigate the smell of oil, discover the cause and submit a plan for remediation, if possible.

 

Phase 1: The initial Visit

 

Richfords fully equipped response unit and technician where dispatched on the 18th June to arrive at Winkleigh at 10am, in accordance with the property owners wishes.

On arrival the technician carried out an initial inspection, survey and spoke with the owner.

It was discovered that there was a strong smell of heating oil evident in the kitchen of the main farmhouse. The owner reported that the farmhouse was now run using propane gas, but that the house did have an oil tank, which was removed 10-12 months ago.

Using a Photo Ionisation Detector (PID) it was discovered that the oil vapour level in the kitchen was higher than would normally be considered safe. The owners were made aware of this verbally and in writing. As a temporary solution it was agreed with the loss adjuster that Richfords would install a local exhaust fan and ducting to remove oil vapours to the outside.

The technician then located the position where the old oil tank had been situated. It was found that the tank had been hard up against the exterior wall of the kitchen and the feed pipe for the oil system was still protruding from the wall. Further use of the PID meter demonstrated that there was evidence of oil contamination in the cob wall structure of the kitchen wall.

 

Phase 2: Window Sampling

 

Following the initial visit Richfords submitted a report to XYZ loss adjusters, which outlined that the oil contamination at Leaping Goat farm appeared to be as a result of the oil tank being situated against the exterior wall of the property and spillages during removal might have been the cause of contamination. However as the tank was not on site and the owners where not present during the removal, it was not possible to ascertain how much oil was lost.

It was recommended that further investigation be carried out. Richfords recommendation was to carry out a geological analysis to assess any potential route of travel for the contamination. This process would include paper analysis with geological maps for the area and also window sampling, where cores would be drilled to assess the depth and spread of the contamination.

Following XYZ’s approval of the further investigation the Richfords team ordered the geological maps for the area of Leaping Goat farm. These maps demonstrated that the farm was situated on heavy clay substrata. As clay is impermeable to oil this evidence suggested that the depth of the contamination would be limited.

Window sample commenced on the 26th July 2006. A series of pilot holes (10mm) where drilled at the base of the exterior wall of the kitchen. The PID meter was then used again to analyses the vapour levels of these holes. Interestingly the level of contamination at the base of the wall was found to be very low.

Therefore the technician team worked systematically up the wall and found that the PID readings increased as they worked up the wall to a height of 1.5m.

Finally as a fail safe the technicians drilled several holes 1-2 meters away from the building to ensure that the contamination was localised. As was suspected there was no evidence of oil in these positions.

In summary the evidence from the geological survey and window sampling demonstrated that the oil contamination in this case was confined to the vertical section of the cob wall of the kitchen of the main farmhouse. The level of contamination was highest at 1.5m, which indicated that oil might have been spilled from the top of the tank during filling over time. This oil had now migrated through the wall to produce the contamination inside the property.

 

Phase 3: The Problem

 

Most oil spills occur horizontally therefore contaminated materials can be dug out and disposed off. The trench left over can then be bio-remediate to eliminated any contamination left over.

However in this case the oil plume was suspended in the wall, which was structural, so how can you remove the oil without taking down the wall?

Revolutionary Vapour Extraction

Richfords proposed to the XYZ loss adjusters that a system of suction pads, usually used for removing moisture from concrete floors, would be fixed to the outside of the kitchen wall, covering the oil plume. These pads would be attached to a side channel blower, which would draw air through the cob and carry the oil vapour with it. XYZ agreed to trial this method.

Immediately following the installation of the suction pads the oil vapour could be measured in the exhaust of the side channel blower. The PID meter detected 60ppm from the exhaust. By comparison the highest reading from within the exterior of the kitchen wall was 15ppm. This clearly demonstrated that the suction pads where concentrating the vapours and extracting them effectively. This success was reported to XYZ.

 

Phase 4: Monitoring

 

As the suction pads and ventilation system were both installed on the exterior of the property and were successful in keeping oil vapours in the property below acceptable levels, the owners where able to remain in residents during the vapour extraction phase, saving alternative accommodation costs.

During the monitoring phase Richfords technicians routinely visited Leaping Goat Farm to take PID readings from the wall and from the side channel blowers exhaust.

Over a period of six months vapour levels in the exhaust fell from 60ppm to just 8ppm. This reduction was accompanied buy a reduction in vapour levels in the property to less than one, with the equipment running.

At this point the equipment was shut down, but remained in place, so that a closing reading could be taken in the kitchen, using the IQRAE remote monitoring unit. This unit was left in for one week continuously monitoring airborne oil levels.

The IQRAE confirmed that the average oil vapour level inside the property was now only less than 1ppm. To finalise the project Richfords reported back to XYZ loss adjusters that the oil vapour within the property was now below safe levels and that there was no evidence of contamination in persistent levels.

 

Phase 5: Finishing

To complete the job Richfords technicians removed all of the equipment from the property. All holes that had been drilled during the remediation process were refilled with materials appropriate to the construction of the property. The exterior wall of the property was repainted and the technician asked the owner if they required any further assistance. They did not and the job was closed.

Upon invoicing XYZ loss adjusters were pleased to find that follwoing this lengthy and challenging project that Richfords final invoice was on target as the amount estimated at the beginning of the project.