Sewage Treatment Plants are sized using three criteria as follows; these are expressed as Pe meaning Population Equivalent.

  1. Flow (Hydraulic Load) expressed in Litres.
  2. Organic Load (BOD) expressed in mg/Litre.
  3. Ammonia (NH3) expressed in mg/Litre.

Current UK loadings are 1 Pe = 180 L/ Day Flow, 60mg/L BOD, & 8mg/L NH3.

We are happy to size any application for enquirers using the industry standard: –

British Water Document: Flows and Loads – 3.

Flows and Loads-3 states that a 3 Bedroom residential property should be sized at a minimum of 5 Pe. For more than 3 Bedroom add 1 Pe for each additional bedroom E.g. a single 4 x Bedroom house = 6 Pe (5+1) a single 5 x Bedroom = 7 Pe (5+2) etc.

Below we list the standard sizes of Package Sewage Treatment Plants available from Synergy Wastewater Treatment Products.

  • 6 Pe will serve up to a 4 Bedroom Property.
  • 8 Pe will serve a 5 or 6 Bedroom Property.
  • 9 Pe will serve up to a 7 Bedroom Property.
  • 10 Pe will serve up to 2 x No. 3 Bedroom Properties or one 8 Bed property.
  • 12 Pe will serve up to 2 x No. 4 Bedroom Properties.
  • 18 Pe will serve up to 4 x No. 3 Bedroom Properties.
  • 24 Pe will serve up to 5 x No. 3 Bedroom Properties.
  • 30 Pe will serve up to 5 x No. 4 Bedroom Properties.
  • 36 Pe will serve up to 6 x No. 4 Bedroom Properties.
  • 42 Pe will serve up to 7 x No. 4 Bedroom Properties.
  • 50 Pe will serve up to 10 x No. 4 Bedroom Properties.

All of the above are available with Gravity or Pumped Outlets, for use where the discharge point is at a higher level.

Obviously there are many combinations of properties with differing numbers of bedrooms, but we hope the above table gives an insight as to what is readily available as standard off the shelf products.

Please contact us with your requirements; we would be delighted to prepare a fully costed proposal, accompanied with a detailed design loading chart for your consideration.

Synergy Wastewater Treatment Products.

E&OE