Lessons from History

When it comes to assessing environmental risk, historical maps could play a vital role in filling the information gap. Richard Pawlyn reports.

The continuing rise in land values has meant that even the most suspect of sites is attracting interest from property investors. This is to the degree that, even should

remediation be necessary, a profit can be made. As a result, demand to develop on non-greenfield sites has never been greater.

But, this is not without risk. Faced with the prospect of a contaminated asset, investors and developers are relying more and more heavily on the guidance, advice and expertise of environmental consultants – and with good reason.

High Court rulings on both the Sevenoaks versus Circular Facilities case, and more recently the Bawtry case (National Grid Gas Plc versus The Environment Agency), where site owners or developers may face considerable costs to clean up contaminated land, have helped propel the issue of environmental risk into

the forefront of the minds of property professionals. The need to be aware of a site’s land use history and follow the correct remediation procedures is paramount to the savvy developer keen to ensure that the finger of liability for clean-up costs of a contaminated site will never be pointed in their direction.

Clients are facing increasing regulatory and legislative pressures, the aftermath of the UK’s booming industrial heritage, along with the government’s high targets for brownfield site development and the associated tax benefits.

All this has meant that the role of the environmental consultant has changed considerably over the past decade – their expertise and value added advice seen as indispensable to the success of a development.

As a result, consultants are increasingly being brought in at a much earlier stage of the development process – particularly as contaminated land is now a condition of the planning application.

But, as the consultants’ role within property development has grown in importance, so has the demand on them to improve the speed and accuracy of the advice they provide. This is to the extent that clients now expect the consultant to be able to pinpoint the exact area most likely to be contaminated, and not just assume that the problem affects the entire site.

This has been seen particularly in the effect of the Landfill Directive, which has meant that there are now much tighter standards on wastes that can go to landfill. The addition of the waste acceptance criteria (WAC) last summer, along with the reduction of the number of hazardous waste sites available for landfill within the UK, has meant that the traditional dig-and-dump approach for an entire site is no longer either a viable or cost effective option.

As a result, the level of information that consultants require for their assessments has changed dramatically. Much more detailed, site-specific information is required to ensure that the consultant is in a strong and confident position to advise on any issues identified. Clients also rely mainly on their consultants to provide them with current best-practice recommendations for the clean up of any risks identified in order to avoid facing future liability claims.

Historical maps have always been an integral part of phase-one site assessments and an invaluable tool in providing an indication of any environmental issues before a site visit.

Commenting on their use of maps, Neil Stothert, Partner at Johnson Poole and Bloomer says: “Detailed mapping is imperative in assisting environmental consultants in phase one of any environmental assessment. Identifying potentially contaminated land by researching the historical land use of a site is always a principal starting point in what we do.”

However, the way consultants access maps, and the level of information provided by them varies greatly. Historically, consultants would have had to spend their time trawling through endless sheets of historical and current maps from either the local authority or library or go direct to individual sources such as the Environment Agency or the British Geological Society.

In 1996, all that changed when Landmark Information Group introduced Envirocheck which enabled consultants to access the Ordnance Survey maps and environmental data they required from one central resource from the comfort of their desks.

High-specification maps, which reveal features such as sensitive land uses, groundwater vulnerability, geology and flooding, are now available at the click of the button.

Landmark have even digitised historical maps dating back to the middle of the 19th century, allowing consultants to accurately assess the changes in a site’s land use over time. Landmark also scanned Ordnance Survey historical town plan maps which date from between 1848 and 1910. This set of 15,000 maps from surveys of all the major towns is available digitally for the first time and are at a scale of 1:500 to 1:5,280. This enables an assessment of a site and its surrounding area at a degree of accuracy never previously possible. The maps reveal potentially contaminative features such as cow houses, brew and bake houses and even cess pits.

This particular set of maps even reveals the division of tenements, interior ground floor layouts of public buildings and functions of larger premises, providing consultants with the most comprehensive picture for accurate risk assessments.

For example, the series of historical maps sown above identifies a carpet factory in Durham. However, the information that they reveal varies considerably in its detail.

While the less detailed maps reveal a factory, the historical town plan map provides much more detail such as the location of the steam loom room, the hand loom room and the spinning shop.

This level of high-quality site-specific information will prove invaluable to consultants who find themselves needing to pinpoint exact areas requiring remediation when investigating a site with a mixture of hazardous and non-hazardous


As awareness of environmental risk continues to be a hot potato among both commercial and consumer audiences, the environmental consultant will be increasingly relied upon to provide guidance through detailed site investigations.

The availability of high-quality maps will remain intrinsically linked to this process. And, as a result, the need to continue to offer consultants access to a range of mapping data from a variety of sources will remain paramount.

Richard Pawlyn is the managing director of Landmark Information Group’s property and environment division

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