Davant

Sizing is based on the number of people the property is designed to serve, not just current occupancy — Davant systems are typically specified from 4 up to 50+ population equivalent. As a rule of thumb, allow for bedrooms plus one to future-proof against extensions or resale. If you're unsure, give us your PE (population equivalent) and we'll confirm the correct model.

Most installations fall under the General Binding Rules if discharging to a suitable watercourse and meeting the criteria, meaning you don't need an Environment Agency permit — but you must still register the discharge with them. If you're discharging to ground via a drainage field, or the site doesn't meet GBR conditions, a permit is required. Building regulations sign-off is separate and always needed regardless of discharge type.

A septic tank simply settles solids and discharges partially treated effluent, which then requires further treatment through a drainage field before it can go to ground — it cannot legally discharge to a watercourse. A Davant sewage treatment plant actively treats the effluent using aeration, producing a cleaner discharge that can, subject to permitting, go straight to a ditch or stream. Treatment plants need an electricity supply; septic tanks don't.

Davant GRP and polyethylene tanks can be installed in high water table conditions, but they need to be correctly anchored and ballasted against flotation as specified in the installation manual, usually with a concrete anti-flotation collar or base slab. Ground conditions affect the excavation and backfill method too, so always follow the manufacturer's installation instructions for your specific site rather than treating it as a standard dig-and-drop job. If in doubt, get a groundworker experienced in off-mains drainage to assess the site first.

Davant treatment plants need an annual service by a competent engineer to check the blower, air diffusers and mechanical components, plus periodic desludging — typically every 6 to 12 months depending on usage and tank size. Septic tanks need less frequent attention but still require desludging, usually annually, to stop solids carrying over into the drainage field. Skipping servicing is the most common cause of premature failure and field clogging.

Davant tanks are delivered on a kerbside pallet or bulk lorry and, given their size and weight, you'll need suitable access and manpower or machinery on site to move them into position — the driver won't carry them into the excavation. Check the tank for transit damage before signing for it, and store it upright and supported if it's not going straight into the ground. Have the installation manual to hand before delivery so groundworks are ready and the tank isn't sitting exposed for long.