Odour Response in Westbury

Odour Update 19 June 2026: Northacre MBT Facility; Westbury

In our previous update, we reported that Hills had an issue with their biofilter and that they had carried out maintenance work which was expected to help reduce odour levels. However, Hills have now confirmed that the new biofilter is currently not operating effectively due to a further fault with the newly installed moisture control sensor. This has resulted in the system becoming too wet and not functioning as designed.

While a back-up system enabled the issue to be identified quickly, we recognise that any increase is concerning and understand the frustration this causes within the community. We have required Hills to take action to rectify this as quickly as possible.

We have independently observed an increase in odour this week, which we attribute to these ongoing biofilter failures. The odour our officers are detecting is primarily that associated with general household waste and not hydrogen sulphide that is present at other waste sites.

Following our investigation and direct engagement with Hills, we have formally identified that the site is currently not compliant with the conditions of its environmental permit. We have made clear to the operator that this situation is unacceptable and have required immediate corrective action.

As a result, we are considering enforcement action and have instructed Hills to resolve the issues with the biofilter as a matter of urgency. Our priority is to ensure the operator meets its legal obligations and that the impact on the community is minimised.

Our officers have been proactively monitoring conditions on site and are continuing to respond promptly to odour reports. This increased level of oversight will continue until we are satisfied that the issues have been fully resolved and that control measures are working reliably.

We want to reassure residents that we are holding the operator to account and taking firm regulatory action to resolve the situation. Your reports play a vital role in supporting this work, and we encourage you to continue reporting any odour incidents.

We appreciate the community’s continued patience and will provide further updates as soon as there is meaningful progress.

Environment Agency staff monitoring odour in Westbury