UK Water Industry Research (UKWIR) has published new research exploring whether wastewater charges for food service businesses should reflect the fat, oil and grease (FOG) content of their discharges, in a shift towards preventative approaches in environmental management.

The study “FOG charging – should foodservice wastewater charges reflect FOG content?” addresses the ongoing operational and environmental challenges associated with wastewater infrastructure. It evaluates the potential of an FOG-based charging model to promote proactive waste management, reduce the risk and cost of sewer blockages, and create a more equitable financial burden for maintaining vital wastewater infrastructure.

FOG as a leading cause of network disruption

Across the UK, FOG accumulation remains one of the most common causes of sewer blockages. According to industry body Water UK, FOG-related incidents cost the UK nearly £200 million annually, with around 70% of these incidents being attributed to foodservice establishments (FSEs). Despite the legal obligation under the Water Industry Act 1991 to prevent waste from blocking the sewer network, approximately 69% of FSEs currently lack a formal FOG management system. Furthermore, more than a fifth of these businesses are unaware of FOG remediation techniques.

“This isn’t just about compliance; it’s about empowering businesses to mitigate costly operational disruptions, protect their brand reputation, and contribute to a healthier water environment. This research is key to highlighting the FOG issue. It can be used by water companies to ensure businesses take action to stop FOG getting into the sewers; therefore, resolving the root cause of blockages with incentivisation”, explained Alison Edwards, drainage and wastewater manager at Welsh Water.

Seasonal impacts and operational costs

The study also examines the effect of seasonal trends on FOG discharge volumes. Increased tourism and food service activity during the summer months can intensify FOG loads. While higher temperatures keep FOG in a fluid state, enabling it to travel farther, cooler winter temperatures lead to solidification. This contributes to more stubborn and extensive blockages.

Historical data indicates an increase in blockage incidents and associated cleanup costs during colder periods, highlighting the seasonal variability in network performance and the resulting strain on utilities.

Framework for equal cost recovery

The research considers the legal context established by Section 111 of the Water Industry Act of 1991, which prohibits businesses from discharging materials that could block sewers. According to the report, a FOG-based charge model could provide a mechanism for proportionally recovering costs from those whose discharges require more intensive management.

“By exploring FOG-specific charges, UKWIR aims to establish a framework that helps businesses streamline their FOG management, ultimately contributing to a more sustainable and cost-effective operation,” explained Edwards.

The full report is available on the UKWIR website.