Crewe and Nantwich Borough Council ceased to exist on April 1st 2009 when its services
and responsibilities transferred to
Cheshire East Council. This website is available for information only.
Septic Tanks and Subsequent Drainage
About 800,000 septic tank systems operate in England and Wales.
The design of the septic tank and its subsequent drainage is
critical in ensuring the efficient working of the system.
Approved Document H2 of the Building Regulations sets out the
minimum requirements to be followed.
Here are some points to consider
:-
THE SEPTIC TANK
When
installing a septic tank always allow for future extensions to the
property. Don't choose the minimum permissible capacity it may not
be cost effective.
Septic tanks can be constructed on-site using brickwork or concrete
but factory made units manufactured from glass reinforced plastics
etc. are the norm.Ideally only tanks possessing a British Standard
of Agreement (BBA) Certificate should be installed and the leading
manufacturers have this certificate.
The siting of septic tanks is important. They should be accessible
for future maintenance or emptying and ideally less than 15 minutes
to a dwelling.
Environmental Engineering Consultants can give expert advice ona ny
such installation.
SUBSEQUENT DRAINAGE
The outfall from a septic tank is usually disposed of by
soakage into the ground provided that the disposal does not
generate a pollution risk to surface waters or groundwater
resources.
The most commonly used form of soakaway is a sub-surface irrigation
area comprising a herrringbone pattern of land drains laid in
shallow shingle filled trenches.
The area of land required for the soakaway system has to be
established by means of a percolation test. It is recommended that
this test is conducted by an independant professional who is able
to provide certificates stating that the ground is suitable and
that the test has been carried out satisfactorily.
Before effluent can be disposed of by soaking into the ground the
consent of the Environment Agency will be required under the
provision of the Water Resources Act 1991.
Useful Addresses and Contact
Numbers:
Environment Agency regional Offices Richard Fairclough House,
Knutsford Road, Warrington, Cheshire, WA4 1HG
Manufacturers of GRP septic tanks Klargester Environmental
Engineering Ltd, College Road, Aston Clinton, Aylesbury,
Buckinghamshire, HP22 5EW, Entec (pollution Control). West Portway,
Andover, Hamoshire, SP10 ELF
Helpful Reading:
Approved Document H, Building Regulations 2002.
Septic Tank Systems: A users Guide: CIRIA
Code of Practice for the Design of small Sewerage Treatment Works
and Cesspools BS6297:1983.
CIRIA Technical Note 146