Pumping stations,septic tanks and treatment works

We are happy to provide independent professional advice on any of the following:

  • Public / Adoptable pumping stations
  • Private pumping stations
  • Septic tanks and cesspools
  • Treatment works
  • Field treatment drain
  • or other natural reed bed systems

Our Director Stephen Gibson is a former Lead Design Engineer for the UK’s largest water company – Thames Water Engineering.

My experience with Thames Water should be invaluable in providing good professional advice in relation to sites with existing sewerage problems or where new sewerage facilities are required. Independent advise is critical before jumping to contractors and manufacturers.

Septic tanks

Septic tanks are not fit and forget items. They need desludging, often on an annual basis. The liquid discharges to a field soakaway system. The field soakaway system provides natural treatment and avoids any point loading. Septic tanks should not discharge to traditional concrete ring soakaways as the treatment potential is limited.

Septic tanks are generally of simple construction. Up to the 1950’s they were generally built on a concrete slab with brickwork. Sometimes the brickwork was formed in a beehive shape. At older sites it is common to find a number of buried septic tanks which are found during groundworks. We can advise how existing unused septic tanks can be made safe.

A failure to discharge from septic tanks is common. It often relates to the field soakaway system being too small, the ground being relatively impermeable and/or siltration over time. It should be assumed that most septic tanks and their soakaway fields have a life span of no more than 50 years. Allowance needs to be made to replace them after this time.

Although septic tanks are relatively cheap, the land and cost of installation of new field soakaways can be considerable. The area for a single dwelling usually exceeds a normal sized garden.

Treatment Works

Package treatment works are now becoming far more common that septic tanks in the UK. There are a wide range of manufacturers using a similar range of proven treatment techniques. A common confusion is that such works discharge on a similar environmental basis as public sewerage systems. This is often not the case discharge standards for public systems are often considerably tighter and more closely monitored.

A package treatment works should not normally discharge straight to a river or stream. In deed, many Local Authorities fail to understand that a treatment works should normally always discharge to a field soakaway drain similar to a septic tank. However the British Standards allow for the scale/area of the soakaway system to be reduced given the reduced suspended solids are higher discharge standard.

Discharge should not normally go to a dry, or low flow ditch, where no additional dilution is naturally available.

Pumping Stations

Where one cannot discharge by gravity to a public sewer, pumping stations are sometimes a better solution long term solution than treatment works. We have extensive experience in the design / specification of pumping stations.