Free Water Supply?

Water Well Drilling
Water Well Drilling

We’ve recently completed construction  of a water well to supply a popular car wash facility in the Swindon area.

Working closely with the main contractor, our careful pre-planning enabled us to install a 40m deep water well in challenging geological conditions, requiring 25m of retrievable casing to be used, all without affecting the site’s redevelopment programme.

On-going site contamination issues dictated that the borehole construction had to be professionally approved and tested before use. But the results of the post-development pump testing confirmed the well would supply a clean water yield in excess of the client’s requirements.

The savings in water supply costs for our client equates to a significant increase in their future profits. What difference would a free supply of 20,000 litres of water a day make to your business?

Contact: Angus Gale Tel: 01296 739471

White Cliffs of Dover

White Cliffs of Dover
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!

Machu Pichu

alma roadOK 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.

Subadra top HSE Audit

Earlier this week our Health and Safety systems were audited by a major oil company. We scored 88%, one of the highest score the auditors have ever recorded and a 4% improvement from the last time we were audited.

Pile Probing Challenge

We do like a challenge, so when a client asked if we could probe 65 pile locations in a single day we said yes. Just to make it more of a challenge our client also wanted soil samples taken from each location and analysed for a range of potential contaminants.

The site was an office car park crammed with cars during the week, so the probing had to take place at the weekend. With noise restrictions preventing Sunday working and project deadlines meaning the work had to be completed in a single day, we knew we would have our work cut out. Each location required us to core the surface pavement, take a soil sample from the upper metre of soil profile and probe to 3.6m depth – a total of 234m of probing. But happily, using our Geoprobe Direct Push drill rig we were able to get everything completed in time to see the kick-off of the FA Cup.

The soil samples were dropped off at our own laboratory later the same day for ‘fast track’ analysis and the results provided to the client 3 days later.

 

When Things Get Tricky

Removing USTs with truss in foreground

Subadra have recently completed what has been, perhaps, our trickiest ever underground tank removal. The tanks at the former filling station were located close to the site boundary. Removing them might destabilise a Victorian house on the adjacent property. To prevent this a contiguous bored pile wall was installed together with a supporting steel truss. Our job was to safely ease the tanks out from under the truss without compromising its structural integrity, before cutting them up and disposing of them as scrap metal. All this on a crowded site with construction of the new structures well underway.

Contract Value £20-£50k

Probing the Depths – Part Two

The headline “ground swallows car” sounds as if it comes straight out of a Hollywood horror film. But it is actually surprisingly common in areas with either chalk or limestone geology or with a history of mining (which could be for clay or salt as well as for coal).

If you are considering constructing foundations you may wish to consider commissioning us to ‘pile probe’ the area first. Not only will this identify shallow obstructions but it will identify swallow holes, solution features and abandoned underground workings such as the ones that caused this:

Ground Swallows Car

Probing the Depths……

Pile Probing Rig

…of Central London in this case. Subadra has completed a week of pile probing at a cramped development site in Central London. Despite obstacles such as leaking water mains, piling rigs and deep excavations we successfully probed sixty locations to verify the presence of below ground obstacles that might impede the construction of the engineers’ piled foundation solution and contiguous boundary piles. The contractor used this information to target additional ground clearance the key areas of concern.
Contract value: <£5k

Satisfying Planning Conditions

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.

Successful Technical Presentation….

Contaminant Contour Plot

Otherwise known as ‘understand your audience’.

We have recently completed a highly complex site investigation and detailed risk assessment of a public amenity site on behalf of a Local Authority. Our technical report, however, needed to be understood by a wide range of stakeholders, including regulators, consultants, site users and the general public. We used a range of graphical presentation methods in our report, cut the industry acronyms to a minimum and offered a report written in ‘plain English’. The result? Clear advice and a happy client, who described our report as ‘a model of site investigation & risk assessment communication’.