Welcome to the Biosolids Assurance Scheme.
Each year, around 3.6 million tonnes of biosolids are recycled to agricultural land in Great Britain, contributing an estimated £50 million in nutrient value to the farming industry.
The Biosolids Assurance Scheme (BAS) operates a standards-based assurance scheme across Great Britain for the treatment and recycling of biosolids to agricultural land, with conformance independently verified through third-party audit.
Sewage sludge arises as a by-product of wastewater treatment, which is essential for public health and environmental protection.
When treated and recycled to agricultural land as biosolids in accordance with regulation and the BAS Standard, biosolids return nutrients and organic matter to the soil, contributing to soil structure, nutrient supply and wider environmental benefits.