CEMEX Hatfield Quarry

Project Description

The project goals were to ensure stockpiles of subsoils and topsoil were restored to their origin and new phase soil strips were segregated in a similar fashion. The overall quantity of material moved was 290,000m3. We developed a mass haul programme and logistics plan to logically complete the reclamation works efficiently and to the project programme milestone deadline, i.e. restoration completion to enable landowner to seed a winter arable crop. The restoration areas encompassed several landowners with no visible defined boundaries. The contract commenced August 2018 and complete November 2018.

Reclamation works

• Load, haul, spread and compact 22,000m³ of stockpiled reject screen material from the quarrying operation to use as fill material to profile depleted land to required undulating contours.
• Load, haul, spread and compact 32,000m³ of stockpiled overburden to form an undulating contour profile over the restoration area. Overburden compacted using a tow behind vibrating roller attached to the crawler dozer.
• Load, haul and spread 24,000m³ of “lower subsoil” material on top of overburden to form a 350mm undulating contour profile layer.
• Load, haul and spread 24,000m³ of “upper subsoil” material on top of “lower subsoil” to form a 350mm undulating contour profile layer.
• Load, haul and spread 10,000m³ of topsoil on top of the “upper subsoil to form a 500mm finished undulating contour profile layer. Upper subsoil was ripped with 390 horsepower tractor with 9 tine heavy duty ripper to a depth of 500mm prior to placing topsoil layer. The finished topsoil layer was again ripped.

New Phase Works

• Topsoil stripping of 35,000m² at circa 300mm deep, under archaeological watching brief. Topsoil hauled to designated stockpile areas.
• Subsoil Stripping of 33,000m³ and hauled to designated storage areas.
• 15,000m³ of Overburden removal and stockpiling in designated storage areas.
• Excavation to stockpile 100,000m³ of ballast mineral, throughout project duration to maintain quarry production.
• Construction of drainage channels to manage ground water as well as managing surface water run off to prevent local watercourse pollution.
• Resources used included 2no 40t excavators, 4no 30t ADT’s, 2no dozers, Tractor and water tanker with ripper attachment.

Project Scope

Scope included 500m of haul road construction, maintenance and removal; setting out including surveying pre & post of each material layer, volume calculations, provision of welfare, and dust suppression.

We developed and utilised GPS machine control dozer models to form contours ensuring restoration soils were placed within each landowners boundary. We cross checked daily telmatic data from ADT’s against weekly land surveys to verify the material movements and contours to the satisfaction of both Quarry Manager and landowner agents.

Important aspect of the works to minimise the impact of wet weather on operations to avoid degradation of subsoil and topsoil. Site Supervisor monitored weather to ensure haul roads and stockpiles were sealed in advance of rain. Works completed on time and to the satisfaction of all parties.