Black lagoons

Date: 2015-10-07; view: 560.

Potentially there are 64,000 hectares (roughly equivalent to half the size of Greater Manchester) of brownfield land available for development in England. However, not all of it is very tempting. Acid tar lagoons present one of the biggest challenges. These black, oily lakes are a relic from the petrochemical and coal processing industries. There are around 150 registered acid tar lagoons in the UK. Sulphuric acid was used to remove impurities during refining and the resulting waste was typically dumped in any locally available holes in the ground. Microbiologists have been able to show that some organisms thrive in this extreme environment.

So what is the best way to manage these extreme environments? One school of thought is that some lagoons should remain undisturbed. "If lagoons are left alone they may not have a large environmental impact, whereas disturbing them typically results in the emissions of significant volumes of sulphur dioxide fumes, which can cause major challenges for remediation," the experts explain.

But even if a clean up is possible, encouraging developers to take on this kind of land is not always easy. One big issue for most developers is deciding what to do with the contaminated soil waste. Dig and dump is still the most frequently used method of dealing with land contamination, but the new EU Landfill Directive has significantly reduced the number of landfill sites which can take contaminated material. Instead developers may have to turn to more sustainable methods of cleaning up land such as bio-remediation, where bacteria gobble up the waste.

Another dilemma is deciding what to build. It is tempting for developers to go for immediate profit and build high-density apartments but this kind of development often lacks infrastructure, jobs and facilities (such as schools, hospitals and shops) and can create a transient, unsustainable community. A more long-term development will use sustainable construction techniques to create a mixed set of houses and facilities that appeals to a range of age and income groups.