- Cian O’Hora
The much-welcomed increase in building activity comes with increases in construction related waste materials. Construction and demolition (C&D) waste volumes have risen rapidly from a low base over the past number of years resulting in challenges for projects as the number of waste outlets has reduced and regulations and producer responsibilities are tightening.
There is a broad range of C&D waste types ranging from clean uncontaminated soil from greenfield sites through to asbestos containing materials and hazardous soils from brownfield sites with industrial heritage. The environmental and public health risks from the waste materials produced during construction work are also wide ranging from benign through to extreme.
Integrated Materials Solutions (IMS) are a relatively new company who specialise in the management of construction related waste materials. Together with their strategic partners, IMS aim to provide an overall solution for construction waste requirements and provide a hands on informed approach to ensure wastes are managed in a compliant, safe and economic manner. The various wastes types, classifications and chemical limits as set out in the Waste Management Act and Landfill Directive are complex. Some materials such as made ground and soils require classification and characterisation via site investigation, sampling and analysis to ensure materials can be appropriately managed. A good site investigation and site characterisation can aid in safe waste disposal and generally saves money and reduces risk for the groundworks aspects of projects.
IMS’s main site is an engineered lined landfill formally operated by Murphy Environmental Hollywood. The landfill is restoring a former shale and limestone quarry which has been active as a landfill since early 2000 under a Waste Licence regulated by the EPA. The licence sets out conditions and standards around the acceptance and deposition of waste at the site including what material types can be accepted. Waste types include mixed C&D waste and brownfield soil and stone which meet the inert limits as specified in the site’s licence.
The site is located off the M1 less then 30km from Dublin City and accepts waste from many parts of the country. The site was the first engineered inert landfill in Ireland and established the bar for managing construction waste and environmental performance. IMS is currently undergoing recertification of their Environmental Management System to the recently updated ISO standard.
IMS recognise that landfilling of material is not the always the most appropriate or favourable solution. They are continually looking to advance materials recovery, recycling and sustainable development and the company has been investing and developing these areas. European and National Waste Policy is strongly supportive of sustainable development and the circular economy when it comes to managing construction and other wastes. However getting a recycled material such as secondary aggregate to market is difficult and requires material to meet End of Waste definition as defined in the Waste Directive. Currently IMS are investing in the necessary studies required to assess the environmental risks of secondary materials with the aim to producing recycled aggregate for resale in the near future. The use of secondary aggregates and construction waste recycling is commonplace in the UK and much of Europe and it is hoped that Ireland will follow suit and increase our waste recovery levels. IMS also promote the reuse of uncontaminated suitable material as a By-Product in construction projects as valuable soils should not be placed in landfills out of the materials loop.
There are a number of materials which are best suited for landfills including contaminated soils such as those containing polluting substances or soils contaminated with invasive species. Japanese Knotweed is one such invasive species and it has become a significant and costly problem which has spread to many parts of Ireland. The plant is extraordinarily aggressive and resilient and poses a substantial threat to the build and natural environment. There are a limited number of options for managing the plant on a site including long term treatment in situ or deep burial (up to 5m below ground level).
The only option to completely remove the plant and associated risk from the site is controlled excavation and offsite disposal. Disposal options in Ireland have been very limited with the majority of impacted soils being shipped abroad to disposal and treatment facilities in Europe. Shipment of material is expensive and presents its own biosecurity risks. IMS have recently received approval for the disposal of soils contaminated with Japanese knotweed soils in a safe and biosecure manner.