How It Works

Principal Of Operation of Sewage Treatment Plant

Stage 1 - Primary Settlement

When sewage enters the primary chamber heavy solids and debris are settled out, floating solids are also retained due to the configuration of the pipe work. Anaerobic digestion also takes place, reducing the B.O.D. of the influent sewage by 30-40% at this stage.

Stage 2 - Aeration

Highly effective aerobic breakdown generated by the now well proven and reliable aeration produces enhanced purification and excellent nitrified effluents.

Stage 3 - Final Settlement

The final settlement chamber ensures that any carryover of partials are retained and a typical final discharge quality of BOD: 18mg/l, SS: 25 mg/l, NH3: 4 mg/l which is equal to an improvement of 85-90% before discharge to the percolation drains.

Siting The Sewage Treatment Plant

BS 6297 : 1983 states that sewage treatment plants should be as far from habitable buildings as economically practicable. The direction of the prevailing wind should be considered in relation to any properties when siting the works. Access should be provided to enable the tank-emptying vehicle to operate within its suction lift capacity. Tanks should be placed out of the way from traffic and wherever possible, pumping should be avoided by locating the plant lower than the premises to be served. Sewage Treatment plants should not be located in an area subject to flooding or where the water table can rise to such levels to cause flow into the treatment units.

Setback Distances

For guidance minimum setback distances for the sewage treatment plant and irrigation area are listed below.

Treatment Plants	Distance From	Irrigation Areas
7m	Dwelling Served	10m
7m	Adjacent Dwelling	10m
3m	Site Boundaries	3m
4m	Roads	4m
10m	Water Course	10m
10m	Drinking Water Sources	30-100m

Contact BioBubble for all your sewage treatment and maintenance requirements.