Normally the simplest and most economical means of treating wastewater from small developments, a septic tank holds sewage and allows solids to settle into sludge at the bottom of the tank. Here it is naturally broken down by a process known as anaerobic digestion, which provides settlement and some biological treatment. The effluent is not fully treated and must receive additional treatment before discharge to the water environment – the most common method being to spread the effluent to land via an underground drainage field.
Marsh Horizontal septic tanks
Marsh Industries’ horizontal septic tanks are available in capacities ranging from 2800 – 20,000+ litres.
Horizontal septic tanks provide settlement and some biological treatment to raw domestic sewage (wastewater), however, the domestic wastewater is not fully treated and must receive additional treatment before discharge to the water environment – the most common method being to spread the waste to land via an underground drainage field.
As an optional extra, Marsh can supply horizontal septic tanks with a unique Polylok filter that is designed to further reduce suspended solids by up to 40% – prolonging system efficiency and drainage field life.
CE ACCREDITED
Providing an impressive hydraulic efficiency of 99.63%
Tested and approved at PIA GmbH, Aachen, Germany
Note: Following British Water regulations for domestic applications, the minimum storage capacity is 2700 litres for a standard four-person dwelling. Following this, each additional user will require an additional 150 litres of storage capacity.

Benefits
- Low profile versions for high water table or hard rock site conditions
- Heavy duty shell as standard to enable installation in all ground conditions
- Integral lifting eyes for improved on-site handling
- ‘Keying-in’ assists anchoring into granular or concrete surround
- Pedestrian cover included as standard
Specifications
Size | Length +/-50mm |
Width +/-50mm | Height +/-50mm | Inlet invert | Inlet dia | Outlet invert | Outlet dia |
---|---|---|---|---|---|---|---|
2800L | 3000 | 1250 | 1750 | 500 | 110 | 800 | 110 |
3800L | 4000 | 1250 | 1750 | 500 | 110 | 800 | 110 |
4500L | 2650 | 1600 | 2100 | 500 | 110 | 800 | 110 |
6000L | 2950 | 1900 | 2400 | 500 | 110 | 800 | 160 |
8000L | 3640 | 1900 | 2400 | 500 | 160 | 800 | 160 |
10000L | 4200 | 1900 | 2400 | 500 | 160 | 800 | 160 |
12000L | 5200 | 1900 | 2400 | 500 | 160 | 800 | 160 |
14000L | 5840 | 1900 | 2400 | 500 | 160 | 800 | 160 |
16000L | 6700 | 1900 | 2400 | 500 | 160 | 800 | 160 |
18000L | 7500 | 1900 | 2400 | 500 | 160 | 800 | 160 |
20000L | 8100 | 1900 | 2400 | 500 | 160 | 800 | 160 |