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When Your Protection Fails….

Overdrilling CP

Not that kind of protection! We’re talking about cathodic protection of fuel pipes and tanks.

Decommissioning and replacing defunct cathodic protection ground beds requires an element of precision and brute force. Our first job is usually locating the existing beds. This can be no small task on a 30 hectare oil terminal site! The redundant beds were installed over 30 years ago and records are sparse.

We used radio detection methods to accurately locate the old redundant vertical ground beds to the required accuracy of +/-50mm. We need to be that accurate in order to successfully overdrill the beds.
Unusually, on our most recent project, our client asked us to drill through the connecting cables rather than removing them. The cables were isolated by a field engineer prior to us starting work and all our works were carried out under a permit to dig.
To overdrill the existing beds we brought in a shell and auger rig, drilling 350mm boreholes to 5m depth. This effectively decommissioned the existing redundant ground beds to make way for the new ones. With the first stage of the project complete, we are now back on site with our Comacchio rotary rig drilling much deeper boreholes in which we will be installing new anodes. Updates to follow.

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Where There’s Muck There’s Brass

Last week we undertook window sampling and installed monitoring wells at one of the largest recycling processing depots in the UK. Have you ever wondered what happens to your recycling after it gets taken away? Well it will likely end up at a processing centre similar to this one, where the waste is separated, segregated and prepared for recycling.
It was eye opening to see the scale of the operation. Usually when we drill, our rig is one of the bigger vehicles on site, but this time our van mounted Geoprobe was dwarfed by some of the other machines on site.

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Heathrow Third Runway

Night Working at Heathrow

OK so we can’t say whether this will (or should) get the final go ahead from government. But what we can say with absolute confidence is that we have more experience of working airside at Heathrow than any other geo-environmental consultant.

We are the only consultant with permanent airside passes, both for our staff and our vehicles. We are also well versed in navigating our way through the airport’s complicated permiting system.

Just last week one of our investigation teams worked through the night to install several deep monitoring wells adjacent to one of the existing runways. The third runway will need thousands of similar geotechnical borehole drilling in the next few years. We believe that having an airside presence and an in depth knowledge of the geology gives us a head start when it comes to providing this service.

For more information please contact James Skinner – 01296 739411

 

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The Good Old Days

We recently came across this advice in a 1960s ‘How To’ manual.

We think the Environment Agency might have something to say if anyone advised this now. But it is typical (albeit on a small scale) of many of the less enlightened environmental practices from earlier times.

This goes some way to explaining why so much of our brownfield land is contaminated in one way or another. With soil and groundwater clean-up costs increasing all the time, it also points up how foolish it is to buy brownfield land without first checking on its condition.

If you’d like to know more about our geo-environmental site investigation capabilities or if you have land that requires treatment, then please contact Duncan Eastland – 01296 739431.

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Cathodic Protection

Installing Cathodic Protection

Drilling large diameter boreholes at a brownfield site to install anodes for a cathodic protection system requires a rather eclectic combination of skills.

Working in a tight space, to a detailed specification, we achieved an anode installation through a complex sequence of geological strata. Clean drilling techniques required us to install an environmental seal through surficial gravels and 30m into underlying clay. We then extended the boreholes through 20m of Thanet sands and 10m of flinty chalk. To complete the anode installation we then tremmied sacrificial coke contact media into the borehole’s response zone with the remainder of the boreholes being grouted back to the surface with bentonite.

Our team consisted of drillers, environmental engineers, mud technicians and cathodic protection engineers, all working together on a busy site to ensure the client got the installation required whilst working within the Environment Agency guidelines.  The anodes will now ensure the pipelines are protected for the next 100 years.

If you’d like to know more or if you have an installation requiring cathodic protection be installed then please contact Angus Gale – 01296739433

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Tight Fit?

Terrier Rig

When it comes to sites that have narrow or restricted access, we reckon that there is no better drill rig than our Terrier. It may be the baby of our drilling fleet, but don’t let its diminutive size fool you.

In the past year it has worked in basements, narrow side passages between houses, amid demolition debris and in a host of other conditions that would have precluded larger rigs being used.

If you add in the fact that it can work on inclines as steep as 30 degrees I think you’ll agree that our Terrier is a little gem.

This week  we’ve been using the Terrier to carry out post-demolition verification sampling. We’ve been able to pick our way through the demolition rubble, getting access to the entire site to drill a pattern of boreholes to 5m depth.

For further information, or to discuss your drilling requirements, please contact Angus Gale – 01296 739433

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Northern Powerhouse?

Pile Probing – Manchester

We like to feel  that we’re contributing to the Northern Powerhouse and this week saw us working in Manchester on a project to construct student accomodation in the city centre. Our role was to clear locations of buried obstructions prior to piling commencing.

We successfully cleared 30 locations to 8m depth in a single day – a total of over 250m linear metres of pile probing. With the piling rig arriving the following day, the result was a happy client.

The fact Manchester was enjoying its warmest day of the year so far was a pure coincidence, though it was a welcome surprise not to get wet*!

For more information or to get a quote for pile probing at your site, please contact Steven Partridge – 01296 739413

[* The editor used to live in Manchester]

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What TLC Can Achieve

Terrier Drill Rig

Our Terrier drill rig, Tinky, recently celebrated its sixteenth birthday. In that time it has had 2 new head gaskets, 15 calibrations, 22 oil changes and services, 2 new tyres, 2 new tracks, 1 rebuilt mast frame, 1 new radiator , 1 new weight guard and a new fan. We know that good maintenance is the key to keeping any machine working and we like to think we’ve done our Terrier proud. It has certainly paid us back.

It may be sixteen years old but last week it still managed to dynamically sample 25m of weathered sandstone to 5m depth with SPT tests every metre plus completing an additional four dynamic probes to competent bedrock at 9.5m and installing four gas monitoring wells to 1.5m. All this in two days including a round trip mobilidsation of over 300 miles. Hats off to Tinky.

We are looking for dynamic sampling operatives. If you think you fit the bill then give Angus Gale a call on 01296 739400 or email your CV to Angus Gale.

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Emergency Response – Filling Station

We were recently contacted following a spillage of several hundred litres of diesel by a customer at a filling station in Northamptonshire. The diesel had entered the site’s drainage system, which ultimately discharged into a nearby area of wetlands.

We were on-site and our spill-response trailer within two hours of receiving the first call. We liaised with site staff, the Fire Brigade, tanker service contractors and the Environment Agency and co-ordinated thesubsequent clean-up, preventing any of the fuel reaching the wetland.

We subsequently collected soil and groundwater samples which were analysed by our in-house UKAS and MCerts accreditted laboratory, with results reported back to our client within 24 hours.

For more information about the emergency response services we offer, please contact James Edley – Tel: 01296 739412

 

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Subadra Partner with River Thame Conservation Trust

River Thame Wetlands

River Thame Conservation Trust and Freshwater Habitats Trust, along with their partners Waddesdon Estate and the Environment Agency, are creating an exciting wetland mosaic on the floodplain of the River Thame, close to our offices in Stoke Mandeville.

They contacted us to ask for our help drilling boreholes and installing groundwater monitoring wells to investigate the underlying geology and hydrogeology of the site. After hearing about the positive impact that the project will have on the local wildlife, we offered to provide a drill crew for the day free of charge.

We know that worthwhile projects like these rely on the goodwill of local people and organisations to make them happen and we’re really happy to have been able to play our part. Despite the hailstones and mud (really, lots and lots of mud – they don’t call them wetlands for nothing) everyone had a worthwhile and fun day.

We look forward to visiting the new wetland when it’s been completed ….but perhaps we will wait until the weather has improved.