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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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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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SUDS (but no soap opera)

The sewage system in the UK is under increasing demands from the increase in rainfall volume and intensity associated with global warming and from the demand of new housing developments.
These pressures required a change in policy approach to a more sustainable system. On 6th April 2015 the government introduced a new planning policy  aiming to lessen the likelihood and impact of surface water flooding from new developments of 10 dwellings or more; or equivalent non-residential or mixed development, by encouraging the use of sustainable drainage systems (SUDS).
Soakaways and permeable paving are two types of SUDS which are used to limit the impact of surface water discharge from new building developments. Designing these systems requires careful measurement of soil permeability. We offer a comprehensive range of testing methods compliant with NHBC (Chapter 5.3) and BRE (Document 365) guidance.

For further information please contact Steve Partridge – 01296 739413

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Water water everywhere….

Something is stirring deep in the Cotswolds….

It may not be quite as lucrative as hitting black gold, but it’s still mighty satisfying to ‘strike’ water as we successfully carry out another water well installation for a private client.

Our Comacchio rig drilled through nearly 40m of clay and limestone in around 4 hours before reaching a productive aquifer. Once we’ve finished installing the well casing and pump, the high quality water it produces will be used to supply an ‘eco-house’ being constructed on the site.

If you are interested in having your own water well installed then please contact Duncan Eastland – 01296 739431 – for more information.

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Rapid ‘CBR’ Testing

Clegg Impact Hammer

Let’s face it, sometimes you just need CBR results fast. Really fast. Maybe you need to identify any soft spots in a piling mat or in a road sub-base before the compaction plant leaves site. Or – be honest – maybe you just forgot to get the required testing done in time. Either way, we have a solution for you. We can test your sub-base using our Clegg Impact Hammer, typically completing 80+ tests in a day with results available immediately. Although the CBR value measurements aren’t as accurate as those obtained from a conventional test, we reckon they are acceptable for about 90% of the enquiries we receive.

For further information please contact Steven Partridge – 01296 739413