Severn Trent wins accreditation for food waste AD plant

Severn Trent's food waste anaerobic digestion (AD) plant at Coleshill in Warwickshire has achieved PAS 110 accreditation for its digestate, which means it can now be used as fertiliser by the agriculture industry.

The plant, which opened last year, recycles 48,000 tonnes of food waste from businesses in and around the Birmingham area. That waste then undergoes AD on site, producing enough methane to power two combined heat and power engines which generate 2.4MW of electricity, or roughly enough to power 4,500 homes.

And now the plant, which was Severn Trent’s first food waste project, has achieved PAS 110 accreditation for the high quality digestate it produces as a result of the AD.

Severn Trent plant manager at Coleshill Jonathan Kendall said: “This is great news for us as it means we not only use the food waste we receive to generate clean power, we can now also offer the product of the AD process to farmers as nutrient rich organic fertiliser.”

The digestate produced by the Coleshill plant is rich in nitrogen, phosphorus and potassium which benefits plant growth and crop yields, and which is also used as a soil conditioner to improve soil structure and permeability.

PAS 110 provides quality assurance and defined digestate standards that meet customer expectations and which comply with the requirements of the WRAP (Waste and Resources Action Programme) and the Environment Agency’s quality protocol for AD, and the BSI’s publicly available specification. The specification means that the digestate is now officially classed as a product rather than as waste.

Severn Trent is currently building a second food waste plant, at Roundhill in Staffordshire, and has plans for a third facility at Spondon in Derbyshire.

A version of this story first appeared on WWTonline.