The drilling fluid will be mixed in specially developed mixing units to obtain the right specific gravity and viscosity. Dry powder will be poured into the mixing hopper. Raw drilling fluid products will where possible be moved to the hopper using mechanical equipment. Manual handling will only be used if absolutely necessary.The fluid that returns to the surface at rig side will be recycled during drilling operations (treated with shale-shakers, de sanders and de-silters ) in order to keep the raw material consumption and disposal volumes as low as possible.The fluid properties will be regularly monitored to ensure the fluid design is appropriate for the ground conditions being drilled through. The specific gravity of the fluid will be recorded, as it is pumped downhole, as it returns to the surface and after cleaning to ensure that the drill cuttings are being removed from the bore and removed from the fluid before re- circulating.The remainder of the drilling fluid will be disposed of in a controlled manner. Bentonite slurry that come out during the drilling operation will be contained in mud pits at rig side during pilot hole drilling and pipe side during reaming / clean passes / pullback operation. COSHH data sheets for the proposed drilling fluid products are included in Appendix