Contamination – Subadra

14 May, 202314 May, 2023

When Skimming is a Good Thing

OK, so when someone says they’ve been skimming, it’s not usually a good thing. However, when it’s skimming fuel from a monitoring well on petrol station, that’s definitely beneficial.

We identified the fuel during a site audit, carried out in response to complaints about petrol odours in off-site (BT and Thames Water) service ducts. Contaminants often track/migrate through ducting and service trenches, leading away from the original source. In this case, our detective work was able to trace the source of the odours back to a fuel leak from the nearby filling station.

Our UKAS accreditted laboratory carried out forensic analysis of the recovered fuel in order to determine it’s age and composition, allowing us to further focus future infrastructure and ground investigation efforts on possible sources of the leak from the filling station.

Being able to seemlessly integrate both site investigation and laboratory testing in this way resulted in significant time and cost savings for our client.

If you’d like to know more about our unique approach to assesment of contaminated land, please contact James Edley.

14 May, 202314 May, 2023

Check Before You Buy

We recently completed a desk-top study for a site with no indication of it’s former use. A thorough, detailed data review uncovered the site’s past use as a petrol filling station. Our subsequent investigations uncovered several abandoned tanks and lots of nasty contamination.

Our report was compiled on behalf of a client looking to lease the site. As a result of our work, they were able to negotiate an indemnity against historical contamination and a contribution to the costs of dealing with future development costs associated with removing the soil contamination. A bullet dodged for our client.

30 March, 202330 March, 2023

A ‘Hole’ Lot of Problems

You never quite know what is lurking beneath the surface. We recently removed this underground fuel storage tank from a disused filling station site. When we inspected the tank we found this large corrosion hole which could have been a major source of contamination. A persuasive argument for replacing legacy single skin tanks with modern double skin tanks!

30 March, 202330 March, 2023

Do I Need to Check for Contamination?

This is probably the most common question we get asked by clients when they are buying a site. The simple answer is almost always yes. Just last week we were asked this exact question. Our client was considering buying a brownfield site for redevelopment and had been given a two year old report prepared by others which gave the site a clean bill of health. Fortunately, they took our advice and had us visit the site to take a look. The photograph shows what we found when we sampled one of the groundwater monitoring wells: ~170mm of free-phase hydrocarbons floating on the water surface. Far from the site being ‘clean’, it had major contamination issues.

9 August, 2019

It’s What You Can’t See….

We were asked to carry out an environmental ground investigation at a disused transport depot. Not surprisingly this identified diesel contamination at ~2m below ground level.

There was no sign of any obvious contamination source and given the site’s previuous use as a transport depot, we thought it likely that an abandoned below ground fuel tank might be present.

We therefore went back to the site and carried out a shallow trial pitting exercise which revealed……well, you can see for yourself.

13 July, 2018

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.

18 June, 201818 June, 2018

What TLC Can Achieve

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.

19 June, 2017

Tesco Fined £8 million for Leak from Filling Station

The latest prosecution by the Environment Agency of a filling station operator has resulted in a record fine of £8 million. The Environment Agency’s investigation found the leak resulted from the operator’s failure to address a known issue with the fuel delivery system and an inadequate alarm system. It was compounded by “poor” emergency procedures. The leak affected local residents and local watercourses, with leaked fuel entering the Langwood Brook resulting in fish kill. County councillor Albert Atkinson, deputy leader of Lancashire County Council, said: “The fact the leak was allowed to continue for more than 24 hours undoubtedly contributed to a risk of harm to people living and working nearby, as well as emergency services attending the incident.”

We believe that this case marks a change in approach from the Environment Agency, with a focus on prosecution under health and safety legislation rather than the available environmental regulations. The resulting fine of £8 million was significantly higher than fines levied for similar incidents prosecuted for polluting controlled waters.

Further details can be found here.

17 February, 201617 February, 2016

When Horizontal Just Won’t Do

A prominent pipeline client came to us with a problem. A ‘positive’ problem that is. A section of their pipeline runs underground next to a railway line. The railway’s overhead high voltage power lines were causing an amplified positive electrode potential in the ground, which in turn was leading to increased corrosion of their pipeline. In these cases, cathodic protection is the usual solution.

A typical cathodic protection system would comprise a series of shallow earthing rods installed at regular intervals along the pipeline. However, this requires access for maintenance in the future to the entire pipeline. But these pipelines run for hundreds of miles through agricultural land, some of which is only accessible during certain periods of the year. The solution was to design a single anode string capable of achieving the required negative electrode potential in a vertical design. Thus saving on space, maintenance and cost

The client’s senior cathodic protection engineer approached us to see if we could drill a 75m deep borehole and undertake the (negative) anode installation. We took the challenge and set about devising a safe method for installing a multi core anode string weighing more than 300kg! The borehole was installed through 18m of gravel into underlying mudstone. Just to complicate matters further, our environmental appraisal identified a potential risk of penetrating into a sandstone aquifer beneath the mudstone. To mitigate these risks and achieve the required potential we had to install a vent pipe to the base of the borehole, a tonne of coke, gravel and a bentonite seal at the top of the mudstone to ensure the underlying aquifer was protected.

Exactly how we did all this is our secret but needless to say it involved a large rig, and unusually for us, a lot of “negativity” ………….But happy pipeline equals happy client – now that’s positive.

5 February, 2016

Earth, Wind and Fire…mostly Fire

It’s never good when your business premises are reduced to ash in a raging inferno. But this was just the scenario faced by one of our clients, when their car showr0om and repair workshop has burnt down overnight.

We were on hand the next day, working closely with both the fire brigade and the demolition crew. We were able to obtain the vital geotechnical data necessary to allow design for the new buildings to progress.
Here you can see our Terrier rig taking soil samples and completing in situ standard penetration tests and dynamic probes to depths of up to 15m.

Now the flames have died out, the demolition has been completed and the new structure has been designed. Our client is well on the way to be back in business.