Question

in a septic tank...... bacteria decompose the sewage

Answer 1

A septic tank produces a very polluting effluent which must be discharged only to a soakaway for further treatment of the septic pollutants by the natural aerobic soil bacteria.

A sewage treatment plant produces a clean, non-polluting effluent which can be discharged directly to a stream ditch or other watercourse, or to a soakaway for dispersal into the soil.

Septic tanks do not require electricity for the process, but all sewage treatment plants, except the BIOROCK, do.  The FilterPod is the first of a new UK generation of sustainable, non-electric sewage systems.

The amount of electricity required by sewage treatment plantsvaries from plant to plant, so it is wise to ask before you buy.

Septic tank systems do not require actual servicing, but sewage treatment plants do.  Again, ask how much the service charge is before you buy.

Septic Tanks require emptying at least once a year, whereas sewage treatment plants have emptying intervals between 3 to 60 months,  Ask before you buy.

Answer 2

In septic tank anaerobic decompose the sewage.