BWB Consulting - Integrated Engineering and Environmental Consultants

Following the implementation of the landfill directive last yearwaste disposal prices have increased considerably. However engineering and environmental consultants, BWB Consulting, firmly believe that with just a little innovative thinking costs can be effectively tackled and reduced.

BWB Consulting is a leading integrated engineering consultancy providing a multi-disciplinary service to the property, development and construction industry throughout the UK and Europe. They aim to use its broad base of specialised skills to come up with original solutions to the new challenges faced by contractors over the removal of waste from construction sites following changes in the landfill directive.

Director at BWB Consulting Tim Loveridge insists waste disposal costs can be cost effectively tackled. He said: ´I do not believe that getting rid of waste from development sites should have to cost huge amounts of money – we just have to be more innovative in our thinking on how to develop the sites we are working on. Initially, methods such as retaining soil on site and working materials back into the construction process can be utilised and this ranges through to more complex remediation processes, including chemical, biological and physical treatment.

´The key to solving waste disposal issues, cost effectively, is the adoption of a multi-disciplinary approach. With our broad knowledge and overview of the construction industry, various solutions can be found to ease the waste issue onsite including raising the floor level, stabilising and treating soils for reuse, or adopting practical segregation and sorting techniques.´

Tim added that in order to ensure clients´ onsite costs are kept to a minimum a proper site investigation and risk assessment should be carried out, materials should be retained on site as much as possible and an earthwork strategy should also be formulated.

The Landfill Directive is intended to reduce the adverse effects of landfill waste on the environment, in particular on surface water, groundwater, soil, air and human health.

It was introduced in 1999 but did not come into effect until last year and initially requires the pre-treatment of hazardous waste and prohibits the co-disposal of hazardous and non-hazardous waste.

Due to these guidelines only a handful of sites can now receive pre-treated hazardous waste and landfill disposal prices have therefore increased dramatically.

Among the new technologies used to treat on site contaminants is the use of bioremediation, which effectively harnesses natural processes and improves the environment allowing optimised breeding conditions for microbes. Above ground this is carried out in bio-piles or soil windows and in the ground through the injection of nutrients, oxygen or food stock. This can stimulate the degradation of complex chemicals in the soil or groundwater into less hazardous compounds, and ultimately into water and carbon dioxide residuals.

Remediation techniques used include immobilisation whereby chemical agents are mixed in to the soil or water to solidify or fix the contaminants into a less or immobile state, others methods include using reactive barriers, soil venting and soil washing.

Tim concluded: ´Some other methods, including thermal treatment, used in the US and Europe have had varying success for some time; however there is on-going research into developing and fine tuning these methods further. We could well see processes such as chemical oxidation, phytoremediation, steam injection, and electro-reclamation which use chemical agents, plants, water vapour and electric currents to remove, immobilise or transport contaminants in the soil utilised in the future. However, there is still significant work and investment needed from the construction industry to take the required technology forward and start delivering results onsite.´