Foul sewage and drainage assessment
|Policy driver||National Planning Policy Framework| Section 10,11 12|
Technical Guidance to the National Planning Policy Framework |
Planning Policy Statement 25: Practice Guide| (or any subsequent replacement following the Taylor review)
Replacement Unitary Development Plan – Policies EP13, EP14, EP19 and EP22
|Type of application||Where the development involves the disposal of trade waste or disposal of foul sewage effluent from a toilet, bathroom, shower or kitchen of a house, flat or business including from pubs, hotels and offices|
|Geographic locations where this information is required||- |
Parts of the Calderdale area that have no public foul sewerage system.
See Calderdale maps on line and also contact Yorkshire Water to enquire where connections might / might not be possible.
Development must connect to a public sewer if within 30m of one, or within an equivalent distance for developments of more than 1 property (eg if within 90m of a public sewer for a development of 3 properties). See ‘Calderdale maps on line’ and also contact Yorkshire Water to enquire where connections might / might not be possible.
|What information is required|
Evidence of there being no connection to sewer possible.
Details of adequate capacity and suitable location of proposed new or existing septic tanks and treatment plants.
Statement as to who is responsible for ongoing maintenance
Please use the following form (This is the current form that is to be updated to reflect latest legislation/guidance )where it is considered that connection to the Public Sewer is not feasible.
Also see Further Information.
|Where to look for further assistance||If, after reading the Further Information you are still unsure as to what to submit please contact the Council's Drainage Engineer on (01422) 39 2949 and Pollution Control Officer for non-mains foul drainage on (01422) 39 2311 / 2373 / 2307.|
Non Mains Sewage Disposal (Septic Tanks and Packaged Treatment Plants)
Paragraphs 20 and 21 of the PPG for Water Supply, Wastewater and Water Quality’ state that “Applications for developments relying on anything other than connection to a public sewage treatment plant should be supported by sufficient information to understand the potential implications for the water environment
Where a connection to a public sewage treatment plant is not feasible a package sewage treatment plant can be considered. (It) should offer treatment so that the final discharge from it meets the standards set by the Environment Agency. A proposal should set out clearly the responsibility and means of operation and management to ensure that the permit is not likely to be infringed in the life of the plant. There may also be effects on amenity and traffic to be considered because of the need for sludge to be removed by tankers
Septic tanks should only be considered if it can be clearly demonstrated by the applicant that discharging into a public sewer “to be treated at a public sewage treatment works or a package sewage treatment plant is not feasible (taking into account cost and/or practicability).”
‘Non Mains Sewage Disposal’ covers several technologies that remove the solids from sewage and expose the remaining liquor to bacteriological degradation before discharging the effluent.
Self-contained packaged treatment plants are preferred because they produce a better quality of effluent prior to discharge. Discharge may be direct to a watercourse, or to a drainage field or drainage mound. (See Building Regulations Approved Document H2|)
Septic tanks only offer basic sewage treatment. They are normally used for small installations e.g. 1-3 dwellings, and should only be used in conjunction with secondary treatment (see Building Regulations Approved Document H2|) such as:
- a settlement tank, to allow solids in the sewage to settle out,
- a filter bed to expose the remaining liquor to bacteriological degradation,
- a soakaway, reed bed or drainage field to distribute liquor over a large area of land, to expose it to further degradation by bacteria in the soil.
Note the advice elsewhere in this document that restricts / prohibits discharges from septic tanks to watercourses, and for the need for environmental permits (issued by the Environment Agency).
Cesspools are not a treatment system. They simply store sewage prior to treatment and disposal off-site. Calderdale will not grant planning permission for new developments using a cesspool.
Other guidance is available in British Standard BS 6297:2007 (amended 2008) and Building Regulations Approved Document H2|
Sewage treatment works must not cause conditions that are prejudicial to health or a nuisance (see Building Act 1984-sections 59 and 126). We want to avoid
- neighbouring property being affected by flies and foul odour,
- water-logging of land or effluent draining onto highways,
- the pollution of watercourses or the contamination of spring water supplies,
- harm to sensitive and protected environments and species.
An environmental permit is needed (issued by the Environment Agency)
- to discharge certain quantities of effluent via a septic tank or packaged treatment plant,
- for tanks and plant and their drainage fields in certain locations. Note a permit will not be granted for a new septic tank to discharge into water. Discharges to water from an existing septic tank will require a permit from 1 January 2020,
- for all new plants and tanks installed after 1 January 2015. Some existing tanks (if the proposal is to join into one) are covered by exemptions to the need to hold an environmental permit. No new exempted installations can be registered.
A permit is only issued for a septic tank or package treatment plant that complies with regulatory requirements. SeeSeptic Tanks and Treatment Plants|,
The Local Planning Authority will not approve developments where the basic requirements for obtaining an environmental permit or meeting Building Regulations are unlikely to be met.
Basic requirements for locating a new septic tank or treatment plant
- All development from which foul sewage is discharged must connect to a public sewer if within 30m of one, or within an equivalent distance for developments of more than 1 property (e.g. if within 90m of a public sewer for a development of 3 properties). See Building Regulations Approved document H1. Refer to ‘Calderdale maps on line’ and contact Yorkshire Water to enquire where public sewers might be present.
- Building Regulations and British Standards point to certain minimum separation distances. Manufacturer’s recommendations may exceed these:
- All parts of a waste water treatment system to be at least 7m from a habitable building, downslope and downwind of the prevailing wind direction (See BS6297). Septic tanks (similarly settlement tanks and filter beds) to be within 30m of suitable access for maintenance. (See Building Regulations Approved Document H2. Note: in other parts of the UK separation distances of 15m are sought between tanks and dwellings).
- Discharge points from a packaged treatment plant to be at least 10m from a watercourse or a building (see Building Regulations Approved Document H2|)
- Drainage fields or mounds (and for this purpose soakaways and reed beds), to terminate
- at least 10m away from a water-course or permeable drain,
- at least 15m from a building,
- at least 50m away from a groundwater supply abstraction point, well, spring, borehole used for human consumption,
- at least 2m from site boundary,
- Not to be located in a Zone 1 groundwater protection zone,
- No driveways, paths etc should cover the disposal area,
- Does not exceed soakage capacity of ground.
(See Building Regulations Approved Document H2 and BS 6297). No new dwelling to be within 15m of an existing cesspool
- Discharges into the ground must be through a drainage field, e.g. an ‘infiltration system’. Septic Tanks and Packaged treatment plant should not discharge
into the protected area around a water supply (known as ‘source protection zone 1’) – check the Groundwater Map|
- into the ground within 50m of a special area of conservation, a special protection area, a Ramsar site or a biological Site of Special Scientific Interest
- into the ground within an ancient woodland
- within 50m of a private water supply for drinking or food production, e.g. a well, spring or borehole
- Discharges into surface water, e.g. a river or stream. Septic Tanks and Packaged treatment plant should not discharge
- into water within 500m of a special area of conservation, a special protection area, a Ramsar site, a biological Site of Special Scientific Interest, freshwater pearl mussel population,
- into water within 200m of an aquatic local nature reserve,
- into water within 50m of an aquatic local wildlife site.
Note: Environmental permits will not be granted for a new septic tank to discharge into water
Developers proposing to connect a new development to an existing septic tank or packaged treatment plant
Developers should be able to demonstrate that the existing tank or plant:
- was installed according to the manufacturer’s specification (i.e. the instruction manual or technical set of requirements that comes with the equipment),
- is large enough to handle the load of existing and proposed development.
- meets the British Standard for septic tanks and sewage treatment plants in force when it was installed (currently BS EN 12566). It should meet those standards if it has a CE mark|
- the manual or other documentation that came with the tank or treatment plant has a certificate of compliance with a British Standard
- it’s on British Water's List of approved equipment|
- is in good repair and good working order. (If it is not, it will not be granted a permit)
Note: An environmental permit will be needed for discharges from an existing septic tank into water from 1 January 2020.