Covid 19 has delayed a number of our projects, but our first piece of site work back is an unusual situation – dealing with contaminated soils in an existing building. The site is a derelict building in central London and the client is a restoration contractor who has been tasked with making the building useable again, including deepening the old cellar to make room for toilets.

The problem is that the soils beneath the basement are heavily contaminated with benzene, a volatile organic compound (VOC) which emits vapour which poses a serious risk to health. The site is in an up and coming part of the city with trendy new apartment blocks but it’s not always been that way – the site used to be in an area of heavy industry with tar, manure and chemical works nearby.

The vapour from benzene poses less of a risk outdoors – it mixes with fresh air and disperses. For the construction workers inside this building, however, it is extremely dangerous. With nowhere to escape, the levels of benzene can cause breathing problems and nausea, and there’s a risk of sparks from machinery or generator engines causing explosions.

Soilutions were called in to review the contractor’s risk assessments and method statements and Phase 2 Ground Investigation report to help with air monitoring to make sure staff weren’t exposed to dangerous levels of benzene and to remove the soils from site for legal disposal.

Soilutions carried out regular VOC air monitoring, inside the building and outside, and carried out occupational health assessments using data from monitors attached to the site workers’ clothing. We updated the risk assessments and method statements and made sure the PPE worn at the site was appropriate. The working area was ventilated and a continuous gas monitoring device was installed  with an alarm set to go off to warn staff to evacuate the area when dangerous levels of benzene were identified.

The soils were classified as hazardous waste – usually this attracts a landfill tax rate of around £95, plus any landfill fees. With a total of 350 tonnes of soil to remove the costs could have been enormous, however Soilutions were able to save the client 80% using our connections with a soil treatment centre.

The project is now drawing to a close, with a new floor slab installed. With the appropriate protection measures recommended by Soilutions, no incidents relating to the benzene in the soils were recorded and Soilutions saved the client over £35,000 in disposal costs.

If you have any questions regarding ground investigations, hazardous soil, soil treatment centres or gas monitoring don’t hesitate to get in touch. We’re happy to talk so feel free to contact us on 0800 0209 307 or e-mail us on info@soilutions.co.uk.

Everything you wanted to know about soil remediation but were afraid to ask!

This free eBook will help you understand the whats, the whys and the hows of soil remediation in the simplest terms. Download it now for free!

Download!

Soilutions are committed to meeting our environmental responsibilities. We have won awards for our recycling of contaminated soils at our soil treatment centre and in the last few years have been trying to lower our carbon footprint. This includes using train travel to get to sites but one of our geotechnical engineers has gone one step further – Luke has been cycling to sites!

With several Phase 2 ground investigations going on we have lots of ground gas monitoring to do. Harmful ground gases such as methane and carbon dioxide are a major risk to human health. Incidents like that at Gorebridge near Edinburgh, where residents were collapsing and their homes had to be demolished, show why including gas monitoring in some Phase 2 intrusive site investigations is crucial.

Luke has been combating this by getting lots of fresh air, cycling up to fifty miles to get to sites with our GA5000 gas monitor to check ground gas levels in the boreholes we have drilled earlier in the year. This soon adds up – the British Standard, BS8485, and other guidance such as CIRIA C665 require six monitoring visits for residential developments!

If you have any questions regarding ground investigations or gas monitoring don’t hesitate to get in touch. We’re happy to talk so feel free to contact us on 0800 0209 307 or e-mail us on info@soilutions.co.uk.

And if you need more information about Phase 1 Desk Studies or Phase 2 Site Investigations you can download our eBooks below:

Guides to Phase 1 Desk Studies / PRA and Phase 2 Site Investigations

These free eBooks will help you learn about Phase 1 Desk Studies / Preliminary Risk Assessments and Phase 2 Site Investigations in the simplest terms. Download them now for free!

Phase 1 Download!

Soilutions are principally known as an environmental consultant, but we also have the capability to carry out geotechnical ground investigations for foundation design. We include a geotechnical assessment as standard in the majority of our Phase 2 ground investigation reports to help clients and structural engineers determine the most appropriate foundation for their development.

We have been working on a former landfill which is to become a housing development. While many people would be surprised to hear that homes are being built on landfills, with appropriate remediation these sites will pose no significant risk to residents. One issue associated with building houses on landfill is the need for deep foundations – the man made ground can be deep and behave unpredictably when the weight of a building is put on top of it.

With this landfill being almost ten metres deep, a piled foundation was required, resting up to a metre into the solid bedrock at the bottom of the landfill. Soilutions worked with the client’s piling contractor to carry out a ground investigation which showed the strength of the soil in the landfill and of the rock beneath it. We used a rotary drilling rig and carried out tests on the ground every 1.50m as we drilled. We also sent samples of the rock to a laboratory for strength testing.

As a result, the client now has a viable foundation design for their development. Soilutions can help you with your foundation investigations, whether they are specialist piled foundations or straight forward traditional strip foundations, and we can save you money by combining a geotechnical investigation for your structural engineer with an environmental investigation required by a planning condition.

If you have any questions regarding ground investigations don’t hesitate to get in touch. We’re happy to talk so feel free to contact us on 0800 0209 307 or e-mail us on info@soilutions.co.uk.

And if you need more information about Phase 1 Desk Studies or Phase 2 Ground Investigations you can download our eBooks below:

Guides to Phase 1 Desk Studies / PRA and Phase 2 Site Investigations

These free eBooks will help you learn about Phase 1 Desk Studies / Preliminary Risk Assessments and Phase 2 Site Investigations in the simplest terms. Download them now for free!

Phase 1 Download!