Blog
Addressing the growing crisis of surface water infiltration and foul water leakage in sewer networks
13 February 2025
Paul Thompson
Technical Specification Manager Alarming statistics from the latest Water Industry Specification (WIS) underscore the scale of this problem, revealing that a single 600x600mm double triangular cover, even within the manufacturing tolerances of industry-standard EN 124, was found to admit up to 22 litres of water per second under certain conditions - this is equivalent to the design peak foul flow from 475 homes. Even at a mere 5mm immersion depth, such covers can admit more than three litres per second. Given that most of the water company’s small "foul-only" pumping stations have a capacity of around 11 litres per second, this represents a significant risk of overloading sewer systems, causing flooding, environmental contamination, and escalating costs for treatment and pumping. Raw sewage entering rivers and seas remains a massive environmental concern, impacting both aquatic life and human health. Environmental groups continue to sound alarms over the devastating effects of pollution, including fish deaths and contaminated drinking water. Collaboration and innovationThe key to solving this challenge lies in collaboration across the industry. By working together, water companies, manufacturers, and regulators can develop and implement solutions that address both the root causes of sewage discharge and the more subtle sources of surface water infiltration. It’s critical that the industry takes a holistic approach to water management, tackling both sewage overflow and leak-tightness to create systems that can handle the demands of modern urban environments. 
Our Unite access covers are designed to support water companies in achieving these goals. By offering retrofittable, high-performance seal plates that, when fitted, achieve compliance with Class 3 leak tightness performance in accordance with Table 1 of Section 2 of WIS 4-26-0. Through this innovation, we can ensure that infrastructure is more resilient, long-lasting, and capable of withstanding the pressures of climate change, population growth, and regulatory demands. As water companies increasingly recognise the value of innovation, there is a commitment to providing sustainable, practical solutions to meet these needs. Top blogs
A sustainable future for water managementThe latest Environment Agency data highlights the urgent need for action to address waterway pollution, which is a growing environmental and public health crisis. The legal, economic, and ecological implications of failing to control surface water infiltration into foul sewer systems cannot be overstated. However, the adoption of proven, low-leak technologies offers a sustainable, cost-effective solution. Through innovation, industry collaboration, and the implementation of WIS-compliant products, water companies can build more resilient sewerage networks that reduce the risk of flooding and environmental damage while improving operational efficiency. With the right solutions, the water industry can not only meet its regulatory obligations but also create a more sustainable future for both the environment and communities. With Wrekin and industry collaboration, our efforts can be at the forefront of this movement, helping water companies achieve their goals through high-performance solutions that reduce leakage, cut costs, and protect waterways. Solutions to combat the problem
Promoting responsibility with Britain's waterwaysThe Sea Starts HereWe're promoting awareness of a simple but important issue on our most popular Tristar D400 gully gratings. Did you know that waste disposed of down gullies, whether at a roadside or pedestrianised area, can end up in the watercourse. This includes rivers, brooks, becks, ditches, leats and culverts. Ultimately, it has the potential to reach the sea, meaning the sea often really does start here. In collaboration with a long-standing house building client, we've taken the notable step to include "The Sea Starts Here" as a message on our highest selling Tristar gully gratings. The message serves as a poignant reminder that our actions on land reverberate to our oceans. |
