Contaminated land has the potential to cause harm to a property, the environment and occupants, and can often come as unwelcome information to both homeowners and developers. The most recent figures estimate that 325,000 sites in the UK, covering an area of 300,000 hectares, are affected by some form of contamination, and if discovered late during construction, could pose a major risk to the future of a project.

Contaminated land may be present in both natural and waste soils, which could pose a potential risk to land users, as well as to adjacent land and the local environment. However, land contamination does not necessarily mean putting a stop to development, and if discovered early during a build can instead help land owners and developers intelligently plan site layouts, prioritise acquisition plans and inform construction processes.

While contamination is not a new topic to those working in construction, Brian Poole, Senior Geologist at Mining Searches UK, outlines why it can prove to be priceless to understand what lies beneath, as well as how technology and information can help developers get the most out of every inch of land.

Safety first

Land is commonly contaminated following the release of hazardous materials or waste, as well as also sometimes being the result of naturally occurring substances. It can also be the result of historic industrial site activities, such as areas used for gas works, mining, landfills or manufacturing.

Contamination is generally defined by the industry as the presence of substances, either natural or man-made, which could pose a risk to people and the surrounding environment. While in most cases the associated risks are low, in some instances residents or land users could become exposed to contaminants, such as harmful soil, water or gases. Contamination could also damage buildings, pollute the surrounding environment and water sources, or in the worst cases be corrosive – causing explosions or fire hazards.

Dependent on the type of contamination present, regardless of whether its natural or man-made, developers and property buyers may find lenders reluctant to proceed with lending agreements due to the perceived risk. Potential homebuyers may also be put off by the possible presence of contamination, making it essential for developers to identify and remediate any issues during the preliminary stages of negotiation or construction.

However, the presence of contamination doesn’t signal disaster, and with the UK Government continuing to push for the development of brownfield sites, investors and developers are increasingly becoming more aware of the opportunities presented by contaminated land.

Ask the experts

During the initial stages of contaminated land acquisition, it’s essential to undertake a full appraisal of the land to understand the types contaminant present, as well as the risks posed to not only future residents, but land users, workers and building materials. This information can also play a significant role during sale negotiations if investigations are conducted early enough – potentially saving hundreds of thousands of pounds in additional remediation costs.

The recent introduction of new predicative modelling means that developers can use the land to its full advantage, and it’s vital that an expert land search firm is employed during the initial stages of any contaminated land development. A full assessment should not only asses the current risk posed on a site, but should also predict future contaminated land hazards, which in turn will allow developers to plan accordingly.

Full risk assessments can play a vital role in not only mitigating risk and negotiating best price but can be a fundamental factor during development design. Investigations should use all available data of known contaminated areas, from historic archives and maps to ground surveys, to not only determine the types of contaminant present, but to also outline what locations are suitable for different types of construction and occupation.

For example, where contamination is relatively low, a map and/or report would outline where is suitable for residential occupation, allotments or gardens. Where contamination is at a higher level, data will also show what parts of the land are suitable for commercial/industrial development, or not suitable for more sensitive proposed uses – this information can also assist with the potential construction phasing of a development.

Old mining features also present unique contamination risks, with topsoil sometimes containing

containing hazardous, naturally-occurring elements such as arsenic which can dictate where various developments can or can’t take place. Land with untreated arsenic present is usually not suitable for home gardens or parks but can be made safe when replaced with clean soil, or hard surfaced with concrete when used for car parks, playing fields or roads. Identification of these areas is key to not only minimise land wastage, but can better inform early development designs and plans, putting every available space to best use.

Smart construction

Although contaminated land may initially signal alarm bells, it often presents developers with a unique opportunity to develop communities and structures built to compliment and integrate with the unique features of the land. However, developers need to ensure that a trusted and industry recognised search organisation is employed to ensure land is completely safe for construction, as well as ensuring that full risk assessments and investigations are undertaken.

By addressing contamination at the earliest possible stages, developers can not only save time and money in the long term but can also ensure the construction of safe and attractive homes and buildings, designed around the best use of the land.