Envirotech

Envirotech plants are sized by population equivalent (PE), based on the number of people the property is designed to serve rather than actual daily occupancy. A typical 4-6 bedroom household will usually need a 6PE unit, but you should always size up if there's potential for future extensions or increased occupancy. Undersizing leads to poor treatment performance and more frequent desludging.

Most domestic Envirotech installations discharging to a watercourse or via drainage field fall under the Environment Agency's General Binding Rules, meaning no formal permit is needed provided you meet the conditions on flow rate, location and distance from buildings or boundaries. If your site doesn't meet those conditions — for example discharge is within 10 metres of a watercourse or in a groundwater source protection zone — you'll need to apply for an environmental permit before installation. Building Regulations approval (Part H) is also required regardless of permit status.

A septic tank only provides primary settlement, so the effluent leaving it still needs further treatment via a drainage field before it's fit to discharge. Envirotech plants use mechanical aeration to actively treat the effluent to a much higher standard, meaning they can discharge directly to a watercourse under the General Binding Rules. This makes them the better option on sites with poor percolation or where a soakaway drainage field isn't practical.

Yes, Envirotech treatment plants use an air blower to aerate the effluent, so they need a permanent mains electricity supply to the unit. Running costs are modest as blowers are low-wattage and typically run intermittently, but you'll need to factor in the cost of getting a power supply to the tank location if it's some distance from the house. A power failure won't cause an immediate problem, but prolonged outages can affect treatment quality.

Most Envirotech plants need desludging roughly once a year, though this depends on actual usage against the design PE — a plant serving fewer people than its rated capacity may go longer between empties. Regular servicing (usually annual) is also required to keep the blower, diffusers and any mechanical parts working correctly and to keep the warranty valid. Always use a licensed waste carrier for desludging and keep the paperwork as evidence of compliance.

Groundwater level and soil type both matter: in high water table areas the tank needs proper anti-flotation measures such as a concrete anchor slab and ballast, as an empty GRP tank can float out of the ground. Access for the delivery vehicle and excavator, along with sufficient depth to achieve a gravity fall from the property, also need checking before you order. Where site conditions are difficult, our technical team can advise on the right tank and installation approach for your ground.