Knollands Septic Tanks & Drainage

help & guidance

Klargester septic tanks


A septic tank is a retention vessel designed to receive sewage, hold it for a period and then release a clarified effluent. Sewage is a mixture of toilet wastes, kitchen wastes and so called grey wastes i.e. liquids which include washing, bath and washing machine wastes.

A septic tank is primarily a liquid/solid separation system, although there may be some limited biological activity within the sludge and the liquid interface.

As the name septic implies, the sewage entering the tank becomes septic. If you look this up in a dictionary or thesaurus, you will see the alternative words, - putrid, toxic, noxious, unsanitary, rotten, decaying. It is possible that at sometime, smells will be detected from somewhere in the drainage system. These can be minimised by correct installation location and by controlling the sewage inputs into the septic tank.

Septic tank factsheets:

Septic tank sizing guide

Flows & loads

Sizing Criteria, Treatment Capacity for Small Wastewater Treatment Systems (Package Plants)

This code of practice was produced by the British Water Packager Sewage Treatment Plant Focus Group.

The Environment Agency, the Environment and Heritage Service (Northern Ireland) and the Scottish Environment Protection Agency support the use of this code of practice, but the Agencies do not specifically endorse any particular manufacturer's product.

The code provides a new table of loadings which allows the total daily load fed into a sewage treatment system to be calculated. These criteria will be widely disseminated and it is recommended that designers of small wastewater treatment systems should use this table of loadings.

The flow and load figures given represent current best practice within the UK but may change with time. British Water welcomes data to improve the content of this document.

Guidance notes are provided to assist the user to consider the nature of the sewage being received for treatment and to identify the various sources of the sewage.

View guidance notes and sizing guide »

Septic Tanks

Our range of septic tanks are suitable for both domestic and commercial applications and for populations of 1 up to 500 people. The Knollands Bio-Pure septic tank is an innovative and cost effective solution and as a result is our best selling septic tank.

Drainage systems

Wether it be agricultural drainage coil, twin walled CorriPipe™ or Hunter sewer drains, Knollands can offer quality drainage systems for a number of different requirements and are perfect for use with our range of septic tanks and rain harvesting products.

rain harvesting

Knollands supply mainly Graf Carat S underground tanks due to their quality construction and reliable design. Convenient packages that include everything you need to start rain harvesting result in a simple and enjoyable project that benefits you and the environment.

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