UK based Drainage engineer - Must be proficient in UK Building regs and NHBC standards, BS-EN codes

Detached self build house requiring on site foul and surface water drainage design back to the existing manhole which is a combined sewer on site which connects back into the mains sewer in the road. Full above and below ground design required with calcs etc prving ventilation and capacity and rain water collection / runoff from the roof, RWGs in Revit preferably