KingspanKlargester

A septic tank simply separates solids from wastewater and relies on the ground (via a drainage field) to treat the remaining liquid. A Klargester sewage treatment plant, such as the BioDisc or BioTec range, actively treats the effluent using aeration and biological processes, producing a cleaner discharge that can often go to a watercourse or ditch under an Environment Agency permit rather than to soakaway.

Sizing is based on population equivalent (PE) — essentially the number of bedrooms or people served, not just current occupancy. Klargester's own guidance and Building Regulations (Part H) recommend sizing for potential future use, so undersizing to save cost now can cause problems later. If in doubt, size up rather than down, especially where extensions or holiday letting are possible.

You don't usually need planning permission just to install a septic tank or treatment plant, but discharges to a watercourse from a sewage treatment plant generally require registration or a permit with the Environment Agency (SEPA in Scotland, NRW in Wales). Discharges to ground via a drainage field are covered under general binding rules provided you meet the criteria. Always check current guidance before installation, as rules on existing septic tank discharges have tightened in recent years.

Standard GRP Klargester tanks are designed for installation in gardens or grassed areas, not under trafficked surfaces, unless a specific traffic-rated cover slab or reinforced access chamber is specified. If a vehicle load is unavoidable, tell us at the point of order so the correct trafficable lid or surround can be supplied — retrofitting is far harder than specifying it upfront.

Most Klargester treatment plants need emptying roughly once a year, though this depends on usage and tank size — your installation handbook will give the specific interval. They also need an annual service by a competent engineer to check the mechanical and electrical components, in line with the manufacturer's warranty conditions and general binding rules. Skipping servicing is the most common cause of plants failing to treat effluent properly.

Confirm the excavation is ready to the correct dimensions and depth, with a suitable base (typically pea shingle or concrete, depending on the model and ground conditions) prepared in advance, as tanks are usually installed on the day of delivery. Check access for the delivery vehicle, as GRP tanks are lightweight but bulky, and some sites need a crane or off-loading assistance for larger plants. Also make sure any groundwater or high water table has been accounted for, as this affects backfill and anchoring requirements.