Contaminated Land
Building on brownfield land? What you need to know about contaminated soils
Contaminated soil is one of the most common surprises on a development site. Here’s how to spot the risk early, what the rules say, and how to keep your project on programme and on budget.
Brownfield land is at the heart of new housing and regeneration across the UK. But land that has been built on, used for industry or filled in the past often has a hidden legacy in the ground: contaminated soil. Dealt with early, it’s a manageable part of the job. Found halfway through groundworks, it can mean stopped work, extra cost and a lot of paperwork.
At a glance
- Brownfield sites often contain soil contaminated by former industrial use, demolition, fly-tipping or old fill and made ground.
- Finding contamination early, through a desk study and site investigation, saves time and money later.
- Soil leaving site must be classified, and hazardous waste must go to a permitted site with full paperwork.
- Where asbestos is found in soil, the Control of Asbestos Regulations 2012 apply.
What counts as contaminated land?
In everyday terms, contaminated land is ground that contains substances that could harm people, wildlife, water or buildings. On development sites, the most common contaminants we come across are:
- Asbestos: broken cement sheet, insulation board, pipe lagging or loose fibres, often left behind when older buildings were demolished
- Hydrocarbons: oil, diesel and petrol from old garages, depots, fuel tanks and machinery
- Heavy metals: such as lead and arsenic, often linked to industrial processes, ash and old fill
- Tars, ash and clinker: common in made ground and on former gasworks and railway land
Sites with a history as factories, petrol stations, garages, scrapyards, railway land or old landfill are the ones most likely to have problems, but contamination can turn up almost anywhere that has been built on before.
Why it matters
Disturbing contaminated soil can put groundworkers, neighbours and future residents at risk, through dust, fibres, vapours or direct contact. It can also pollute groundwater and nearby watercourses. And from a project point of view, an unexpected find can halt work while the material is assessed, add disposal costs and hold up the discharge of planning conditions.
Planning and the rules
When a site may be contaminated, local planning authorities commonly attach land contamination conditions to a planning permission. These usually require the developer to investigate the site, deal with any contamination and provide evidence that it has been done before the development is occupied.
The Environment Agency’s Land contamination risk management (LCRM) guidance sets out the recognised approach: assess the risks, choose the right way of dealing with them, carry out the work and then verify that it has worked. Following this approach, and keeping good records at every stage, makes it much easier to sign off your planning conditions.
What happens to the soil?
Any contaminated soil that leaves site is classed as waste, and the law is strict about how it is handled.
- Classification: soil has to be assessed and classified, using the UK’s WM3 waste classification guidance, as hazardous or non-hazardous before it goes anywhere.
- Duty of care: everyone who produces, moves or disposes of waste has a legal duty to make sure it is handled safely and ends up at the right site.
- Paperwork: hazardous waste must travel with a consignment note, and records should be kept for your files.
- Reuse: in some cases, suitable soils can be reused on site under an agreed approach, which can cut disposal costs. This needs planning with your consultant before any material is moved.
Found something unexpected during groundworks? Stop work in that area, keep people away and get the material assessed before carrying on.
Asbestos in soil
Asbestos is one of the most common contaminants on brownfield sites, and it brings its own rules. The Control of Asbestos Regulations 2012 apply to asbestos in soil and in construction and demolition materials, just as they do inside buildings. Industry guidance known as CAR-SOIL, published by CL:AIRE, explains how to assess the risk and decide whether the work needs a licensed contractor. That’s why it pays to use a contractor who is experienced with both contaminated soils and asbestos.
Tips for developers and groundworkers
- Investigate early: a desk study and site investigation before work starts are far cheaper than dealing with surprises later.
- Budget for it: allow a contingency for contaminated material, especially on sites with an industrial history.
- Keep stockpiles separate: mixing contaminated and clean soil can turn a small problem into a big disposal bill.
- Keep the paperwork: classification results, consignment notes and validation reports all help to discharge planning conditions.
- Use specialists: choose a contractor who can investigate, remove, dispose of and validate the work, all under one roof.
How SAR can help
Our contaminated land removal service covers the whole job, from site investigation and sampling to excavation, waste classification, legal disposal and validation. We supply all plant and equipment with fully trained drivers, use skips lined for hazardous waste, and give you the records you need for your client, consultant and local authority. And because we’re licensed asbestos specialists, we can deal with asbestos in soil as part of the same job.
If you have a site coming up, or you’ve found something unexpected, get in touch for free advice and a no-obligation quote.
Got a contaminated site? Let’s talk.
Tell us about your site and programme, and we’ll arrange a visit and a free, no-obligation quote. We’re available by phone, email, WhatsApp or our enquiry form, and we look forward to helping you.