The first step necessary to enable development of the safe working methodology was to better characterise the stockpile, therefore samples were obtained using a hand-held window sampler under controlled conditions i.e. sample positions were dampened prior to sampling and operatives wore face masks whilst samples were obtained. Independent air monitoring was carried out to verify control measures were effective. All samples were sent for a broad range of chemical parameters, including asbestos. The results assisted characterising the waste for operational and disposal purposes.
A pre-start meeting was held on site on the 17th June 2016 with our Client and the adjacent construction company to ensure all parties were happy with the forthcoming disposal works and to reassure that their workforce was not going to be exposed to any risks during the disposal works.
A safe system of work was developed by Sirius (consisting of method statement, risk assessments and construction phase plan) and approved by our Client’s health and safety advisor.
Sirius mobilised to site on the 27th June 2016 to set-up the site, fencing, take delivery of plant, materials etc. In addition, Sirius erected temporary fencing around the parking bays and footpath adjacent the eastern site boundary to effectively close and make safe this area. This also enabled mature vegetation present along the eastern edge of the stockpile to be removed by specialist subcontractor and ensure none was attached to the wall itself and prevent destabilising the wall during the stockpile removal works.
Following mobilisation, site set-up and vegetation clearance the disposal works commenced the following day. During the works dust mitigation measures were employed which consisted of spraying the stockpile during excavation with a surfactant/water mixture and auto spraying wagon contents with a water/PVC sealant before they left site.
Leeds City Council’s Geotechnical Section undertook full-time supervision during the works.
During excavation and loading of the stockpile material a watching brief was carried out by a ‘Category B’ non-licensed asbestos work qualified operative, any observable fragments of asbestos within the stockpile material were removed by hand double-bagged and transferred to a sealed/lockable skip for disposal as hazardous waste.
During the works independent full time air monitoring was carried out to monitor fibres in air and verify whether the control measures and working practices being employed were mitigating fibre release.
Daily air monitoring results consistently showed fibre release to be none detect or well within prescribed safe limits in accordance with HSG248.
Although the bulk of the material was taken to a licensed non-hazardous landfill other waste streams needed to be dealt with including green waste (vegetation) general waste (rubbish and putrescible materials) concrete and hazardous asbestos which were all segregated, loaded into large skips/bins and disposed off-site at appropriate landfill facilities.
A road sweeper was employed full-time on the road outside the site to ensure the highway remained free of mud and debris.
The works were successfully completed on budget and within programme. No complaints were received during the course of the works.
The Client and their representatives were satisfied the works were undertaken efficiently, professionally and competently.
