Botley treatment centre gains approval to supply biosolids for agricultural use

A new sludge treatment facility in Hampshire has been officially certified to supply biosolids for local farms, offering an eco-friendly alternative to chemical fertilisers for crop cultivation.
The CSG Botley Treatment Plant, which began operations last year, has received certification from the Biosolids Assurance Scheme (BAS). This approval ensures that the biosolidsproduced from the sewage treated at the facility meet the required safety standards for use on farms growing crops that comply with Red Tractor certification.

Biosolids, created through the treatment of wastewater sludge, are rich in essential nutrients like nitrogen, phosphorus, and micronutrients, making them an invaluable resource forsustainable agriculture.

Currently, the Botley plant processes 25,000 gallons (114,000 litres) of raw sewage daily from off-mains households and businesses across Hampshire. The facility’s goal is to produce400 tonnes of enhanced lime-treated biosolids annually, offering local farmers a cost-effective, organic fertiliser alternative to traditional chemical options.

James Baxter, Agricultural Recycling Manager at CSG, commented: "We're thrilled to have achieved BAS certification, a key milestone since the launch of this £1.3 million treatmentcentre. We've already produced over 125 tonnes of biosolids, which have been distributed to local farms as fertiliser. With this accreditation, the biosolids can now be used on fields that grow Red Tractor standard crops, including the food you find in supermarkets."

“At CSG, we’re dedicated to developing innovative recycling solutions that reduce environmental impact, and the production of high-quality biosolids is a great example of this approach.”
To produce these biosolids, CSG employs cutting-edge centrifuge technology to separate wastewater from solids, resulting in a lightweight, sanitised ‘cake’ that is easily transportable tofarms.

As part of the BAS programme, biosolids undergo rigorous testing to ensure they meet the necessary safety standards. Regular audits also ensure the ongoing quality and compliance of the product.

The Botley Treatment Centre plays a vital role in addressing wastewater capacity needs across Hampshire, supporting over 8,000 off-mains households annually. The facility accepts wastewater from homes, hotels, and holiday parks that rely on septic tanks or cesspits instead of mains sewage systems.

CSG is a leading operator in the UK, managing wastewater from 30,000 off-mains households nationwide.

James Baxter added: "Facilities like the Botley plant are essential to tackle the growing wastewater capacity challenges across the country. This centre has a significant capacity and is already making a positive impact on the local community."

The Botley site is built to the latest specifications and is fully licensed and permitted by the Environment Agency.