Chalk Aquifer – Subadra

21 August, 201721 August, 2017

What Did You Do Last Night?

Maybe we are cynical but we usually reckon we can rely on the weather to be cold and raining, or even snowing, anytime we are asked to carry out sitework at night. So it made a pleasant change to find ourselves at the end of Runway 27R at Heathrow on a warm summer’s night last week. As a Heathrow Approved Contractor we’d been asked to carry out some urgent groundwater assessment work and because our staff and vehicles hold ‘access all areas’ passes for Heathrow, we were able to be on site quickly and with the minimum of fuss.

For more information regarding our site investigation and remediation capabilities at airports, please contact James Skinner – 01296 739411

6 March, 20156 March, 2015

When You Need to Know Fast

Our Geoprobe Drilling Systems offer something a little special when it comes to rapidly investigating a site. And when coupled with the fast turnaround from our UKAS and MCerts laboratory, our clients benefit from the best of all worlds.

We were asked to investigate a large industrial site that had a history of fuel contamination issues. The question was: how far had the contamination spread and was it migrating under the neighbouring properties. Our solution was to carry out a groundwater probing survey, comprising driving a re-useable probe into the ground to the underlying groundwater and then taking a sample of the groundwater for laboratory analysis.

We completed 54 probes in two days, accurately delineating the hydrocarbon plume. Forensic analysis of the samples by our laboratory then confirmed that there were three separate sources of the hydrocarbons, two of which were ongoing leaks, and not just the one known historic source.

We now know what the problems are, how far the contamination has spread and how to clean it up. Isn’t that better than endless phases of investigation last months and costing £££s.

Project value: £10-£15k

5 November, 20145 November, 2014

White Cliffs of Dover

We were commissioned to carry out a geotechnical investigation, including rock coring, at a site located just a stone’s throw from the busy harbour of Dover.

Our Commachio 205 and drilling crew were able to produce high quality cores and gain SPT/CPT data from 4 boreholes, each drilled to a depth of 20m below ground level. All completed on time and on budget.

Voids were encountered at various depths fueling rumours of secret smuggling tunnels similar to those we found in Margate last year. Unfortunately the only treasure recovered were metres and metres of chalk. Better luck next time lads!

17 October, 2014

Machu Pichu

OK so not exactly Peru, but a very steep, terraced site in the Chilterns.

The extremely tight access didn’t prevent our site team from getting in and completing a comprehensive geotechnical investigation, including soil sampling and dynamic probing to 10m depth. The work was completed on time and on budget, with dynamic probing data issued to the client on a ‘same day’ basis to assist with pile design.

11 July, 2014

Tight Access for Investigation

We have recently completed an incident response investigation of a domestic heating oil installation located at the centre of a residential accommodation block complex in southern England. The site overlies chalk and is located just 100m from a public drinking water supply borehole.

Following complaints of possible oil contamination issues from the residents we took samples of the underlying soils and audited the fuel installation. With only footpaths leading to the tank installation we used our Terrier drilling system – which can fit through a standard doorway – to install boreholes either side of the oil tank and take soil samples for rapid analysis in our UKAS laboratory. Fortunately no significant soil contamination had occurred and our recommended improvements to the installation are now underway. The entire project, from initial enquiry instruction to report issue, was completed in under 4 days.

Project value ~£2k. Client value £££

11 November, 201313 November, 2013

Satisfying Planning Conditions

Tank Excavation — Look What We Found....

Environmental planning conditions are commonplace in brownfield development and much of our work is involved in the negotiation of discharge of such conditions. We have developed excellent relationships with Planning Authorities and Environment Agency/Scottish Environment Protection Agency over the years and enjoy a good success rate in planning condition discharge.

Earlier in the year Subadra were commissioned to assist in a significant phased retail development on the south coast of England. The site is within Zone I of a Source Protection Zone, overlies Chalk and is 40m from surface water. In other words it is in an extremely environmentally sensitive location. Initial investigation works had identified diesel and waste oil in shallow groundwater under the site.

This is where owning our own drill rigs and our own laboratory comes into play! We were able to delineate and characterise the contamination, and install sentinel wells within a month and without delaying the build programme. As a result of our detailed assessment, we’ve negotiated a long-term remedial solution for the site, installed the required groundworks and construction works have commenced.

3 January, 2013

Out on the Wiley, Windy Moors

December saw us out in the middle of Dartmoor drilling water wells. Frail insfrastucture and maintenance issues had driven one Devonian farmer to drinking water distraction. The water well supplying their property was a shared supply and each year they were expected to contribute to the maintenance of the lengthy, unreliable water pipe. We were commissioned to design and install a new well to serve just their property, together with all associated pipework, electrics, buffer tank etc as a ‘turnkey’ package.

We used modern installation techniques and our Comacchio drill rig, capable of drilling in excess of 100m, to construct a 46m deep borehole lined with a modern PVC screen, a graded filter pack, cattleproof/watertight inspection chamber, ducting into the property, cabling, pipe work, pressure vessel, on demand water flow controls, piped into the existing supply and insultated against the hardest frost. All works were completed in only four days.

If you’d like to know more about our water well installation service or would like a quote for your own water supply, please call Duncan Eastland (Tel. 01296 739431).

17 October, 201217 October, 2012

Subadra Awarded Multi-site Remediation Portfolio

We have been awarded a major remediation portfolio by one of the UK’s biggest fuel retailers. The multi-site portfolio will see us working at a sites across the UK using a wide variety of both in situ and ex situ remediation techniques. We understand that a key reason for us winning this work was our ability to provide cost-effective turnkey solutions, integrating site investigation, laboratory testing, fate-transport modelling and remediation design and implimentation using solely in house resources.

20 April, 201220 April, 2012

Remediation Following Filling Station Fuel Leak

It’s not often that we post anything about our remediation projects. Mostly this is because they are often covered by confidentiality agreements and sometimes because they are too complex to be neatly summarised in a few paragraphs. So it’s nice to be able to report the successful completion of a remediation project at a filling station site in London. Over the Christmas holiday one of the tanks at the site was found to be leaking. The site is located in a very sensitive area environmentally: in a source protection zone and directly above London’s chalk aquifer. Despite the holiday festivities, we were able to mobilise a drilling team to the site. Our investigation quickly delineated the contaminated soil, with our in-house laboratory reporting their analysis results within 48 hours of sampling. This in turn meant we were able to excavate and treat the soil before the leaked fuel had a chance to penetrate to the underlying aquifer, saving our client from having to carry out a costly and time consuming groundwater treatment.

Contract Value £10-20k