Geo-Environmental Services
Tom Petzing, one of our Geoprobe operators, last week smashed our long-held drilling record completing 218m (yes, that really is two hundred and eighteen metres) of pile probing in a single day. The deepest location was probed to a depth of 32.4m, or 106ft in old money, which means that Tom joins our Managing Director as a member of the elite Geoprobe 100ft club. Well done Tom, the t-shirt is in the post!
OK we can’t really claim to be representative of the economy as a whole, but our recent workload suggests that construction activity is at last starting to pick up. In particular, our CBR and Plate Bearing teams have had their busiest month ever: in fact, they’ve been so busy that we have had to invest in more equipment to meet demand. We’re also seeing an upturn in demand for pile probing surveys which suggests that more constuction projects are getting into the ground. If you’d like to discuss your requirements for any of these services then please contact us here.
Sadly not in this case. But what do you do if you’re digging a hole and it fills with a horrible mixture of black fuel and water? Call Subadra of course! We are able to guide you with all aspects of contaminated ground from waste disposal or how to minimise the impact on your development programme to how to discharge your planning conditions.
The site in the photo is a filling station that is currently undergoing a full site redevelopment. When the contractor opened up the forecourt to remove the below ground fuel tanks the excavation filled with a heady mix of petrol and diesel that had accumulated over the years around the off-set fill points.
We were on-site within 2hours of being contacted. We collected water and soil samples from the excavation that were run through our in-house hydrocarbon laboratory. The results were issued within 48hours allowing the contractor to efficiently deal with the soil disposal and avoid costly delays to the works programme.
Subadra have been appointed by the Retail Motor Industry Federation (RMI) to provide specialist environmental advice to their members. The RMI represents the interests of petrol retailers and forecourt operators across the UK. They provide support on matters ranging from contaminated fuel problems to getting a better deal with your fuel supplier.
We join their technical support team in providing practical and sensible advise for all matters associated with fuel leaks, spills and ground contamination issues.
Whether you need guiding through the planning process during a site redevelopment or you suspect you may have had a fuel leak – we can help.
Please contact James Edley(Tel. 01296 739412 or email) for further information.
Subadra have recently been awarded a package of investigation works by one of the major oil companies. We were selected based upon our continued excellent working relationships with the end client and their project managers , continuing to provide a high quality service and as always being able to offer cost effective site investigation services.
Particular praise was made of the quality of our tender submission, highlighting key areas of excellence and capabilities which enabled the client to quickly and easily conclude that we were the service provider best suited to complete the works.
The works package includes investigating 12 retail filling sites using our GeoProbe direct-push drilling system. The majority of the chemical analysis will be completed by our UKAS accredited laboratory. The reporting deadlines for the package is six weeks from the point of instruction. Contact value: ~£55k+
There are always cost savings to be made when multi-site packages are being completed and we like to pass these savings onto the client. If you have a small network of filling station sites or are a ‘Top-50’ operator and need an environmental survey get in touch to discuss our highly competitive rates.
Whilst much of our work in carried out in the provinces we sometimes dabble with high finance in the City.
Subadra played a key role in the development of an £80 million multi-storey data centre facility in London’s docklands area. We were brought in at the inception of the project to carry out a geotechnical and environmental investigation to determine ground conditions.
Our investigation comprised a network of boreholes across the development area that were used to collect soil samples for analysis and groundwater and hazardous gas monitoring points.
The site was especially tricky geotechnically, comprising areas of in-filled docks, some highly contaminated and others containing very soft silts and clays.
We used the data to assist with foundation design and the classification of waste soil.
Contract value: £20-50k
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
Encountering obstructions during piling works and clearing these obstructions can cause significant cost implications and also impact upon the construction programme. However, delays and significant cost-overuns can be avoided by completing a quick and easy pile probing survey.
We recently carried out a pile probing exercise a high profile redevelopment project in central London. The principal contractor identified an old, below-ground fuel tank that needed to be removed. Due to adverse ground conditions and proximity to a basement and the adjacent road, sheet piling around the tank prior to its removal was considered the most effective and safest option.
We were brought in prior to the piling rig to identify an obstruction free boundary around the tank to allow the piling to be undertaken. We completed 400m+ of probing in two days using our Geoprobe drill rig, completing the works on budget and ahead of schedule.
Additionally, despite the working area having been surveyed and declared “service-free” by the principal contractor our drill team, who are all trained in service detection, identified a 4″ water main in our specified working area during our pre-enabling The findings from our probing allowed the pile design to be refined and the service clearance works we carried out avoided everyone from getting very wet.
Contract value: <£10k
See also: Mayfair Hotel
We’ve installed thousands of groundwater wells in our time, although admittedly the
water we pump from them is usually contaminated and in need of treatment! We have
recently been contacted by a concerned gardener in the Thames Valley, worrying about
water supplies this summer. We used one of our rotary drilling rigs to install a 12m deep
groundwater well for irrigation purposes, installing the required pump and pipework as part of the contract. Our rotary auger rig only needs a metre wide access, making it ideal for accessing garden areas. Our drillers also prefer working on a site where tea and cakes are on offer!
Japanese knotweed is is a highly invasive plant found throughout the UK. It is capable of growing 10cm per day, breaking though weaknesses in buildings, foundations, concrete and tarmac.
Whilst physical damage to foundations and structures is the most visible problem associated with a knotweed infestation, its presence can also lead to significant reductions in land value and restrictions on redevelopment. Planning authorities will require the eradication of knotweed as a planning condition that must be completed prior to development.
During a recent site visit to scope demolition and site remediation works we identified a clump of knotweed. Our client was intending to purchase the site and the knotweed’s presence had not been picked up by their valuation survey.
The projected costs for dealing with the knotweed we identified was ~£30k. With our assistance our client was able to negotiate a reduction in purchase price to offset the necessary remedial costs. Our client has since purchased the site and we managed the knotweed remediation as part of the wider site clearance works. The works were completed on time and on budget and come with a 10year guarantee.
Would you recognise a knotweed rhizome? If not, call us to arrange a site survey. Contact James Edley – Tel: 01296 739412