Cesspools

Drainstore.com is pleased to supply a wide range of Cesspools and Silage Tanks up to 84,000 Litres.

Should you be unable to find the cesspool or silage tank from the products listed, please give our sales department a call on 01773 767611.

Cesspool & Silage Tanks: Information


Cesspools are purely a holding tank without an outlet, and will require emptying on a frequent basis depending on usage.

Cesspools act as a solution for locations without mains drainage where the discharge of treated effluent is not permissable due to unsuitable ground conditions, or where infrequent use such as for a holiday home would prevent the use of a septic tank or packaged sewage treatment plant. 

Standard sizes range from 1,000 litres to 84,000 litres, however larger tanks are available. Please ask for further details.

Sizing criteria for cesspools

British Water sizing criteria should be used when calculating the capacity of a cesspool based on a loading of 200 litres per person per day in residential applications. The tank should be of a sufficient capacity to hold 45 days worth of effluent. For a single dwelling 18,000 litres (4,000 gallons) is the minimum allowable capacity. This capacity is suitable for two residents only.

For non-domestic applications refer to Drainstore for advice on the capacity and type of tank required.

Manufacturers strongly recommend the installation of a high level alarm on cesspools in order that the level in the cesspool can be monitored and to ensure spillage or a disruption in service is minimised.

Drainstore.com supply all manufacturers and all sizes. If you cannot find the system you require, please call our sales team on 01773 767611 for more information.

Silage Tanks

Silage tanks are manufactured in the same sizes as cesspools and are used for the storage of more toxic natural or chamical waste. Silage tanks are manufactured using special resins designed to be resistant to aggressive silage effluent and to comply with all statutory regulations.

Silage effluent has the potential to cause severe environmental damage if allowed to enter a watercourse as it has a very high BOD (Biochemical Oxygen Demand), up to 200 times greater than that of domestic sewage. Therefore, if it enters a watercourse it can very quickly remove all of the oxygen and kill off all aquatic life withing the ecosystem.

As silage effluent has caused numerous severe pollution incidents in the countryside, there are now a number of very strict statutory controls to regulate its collection and storage.

A typical application for a silage tank would be for a touring caravan site where a collection vessel was required to hold elsen waste from chemical toilet cassettes.

Standard sizes for silage tanks range from 1,000 litres to 84,000 litres, however larger tanks are available. Please ask for further details.


Please ensure the terms and conditions of contract are read and fully understood prior to any order.

Please call 01773 767611 should this specific size of silage tank be required.


For installation instructions for cesspools please click the PDF links below.

  • Clearwater__Cesspool_&_Septic_Tank_Installation_Guidelines.pdf - 53 kb
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  • Installation_instructions_for_septic_tanks,_cesspools_&_silage_tanks_-Concrete_Surround.pdf - 417 kb
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  • Installation_instructions_for_septic_tanks,_cesspools_&_silage_tanks_-_Granular_Surround.pdf - 579 kb
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  • clearwater_klargester_kingspan_shallow_dig_silage_tank_drawing.pdf - 103 kb
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  • clearwater_klargester_kingspan_shallow_dig_silage_tank_installation_guidelines.pdf - 535 kb
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