Ensuring Worker Safety During Upgrades at Welsh Water Infrastructure at Clyro

Project Overview

Dŵr Cymru Welsh Water engaged Capital Delivery Alliance, a consortium of external experts, to undertake the most extensive investigation of water conditions ever conducted along the Welsh coast. As part of this ambitious project, Morgan Sindall was appointed to execute a five-year program focused on enhancing the sewerage network and wastewater treatment facilities.

Morgan Sindall's responsibilities included a wide range of improvements, including mitigating the risk of sewer flooding for individual properties, investigating and preventing environmental pollution, and implementing technologies that are new to the UK.

A key component of Morgan Sindall’s program involved significant construction work at the Clyro Welsh Water Waste Treatment Works.

Challenge

During a major upgrade at the Clyro Welsh Water site, Morgan Sindall faced significant challenges, needing to excavate within a 7m x 7m x 8m cofferdam. Ensuring the safety and well-being of the team working within this space was paramount, particularly maintaining good air quality to prevent health issues.

The excavation process introduced additional hazards. A 3-tonne excavator was required to be lowered into the cofferdam, and its emissions posed a risk of reaching dangerous levels of gas in a confined environment, particularly Carbon Monoxide.

To address these challenges, Morgan Sindall consulted with GAP for a solution. Upon evaluation of this project’s complex requirements, GAP identified that a specialist ventilation solution was required, so reached out to their trusted trade partner RVT Group. Following a thorough review of the site, RVT Group recommended a fully compliant solution that would effectively manage air quality and hazard control within the cofferdam.

Solution

Based on the size of the cofferdam, RVT calculated that a powerful VENTEX^® Axial Fan 450M with an airflow of up to 10,000m³/h would be the best solution to maintain good air quality. The fan was positioned at the opening, and continuously forced fresh air from higher ground through flexible ducting into the cofferdam to ensure constant fresh air flow, diluting harmful fumes during works and protecting workers.

As the excavator was in an enclosed space, workers were more at risk of high levels of exposure to harmful gases such as Carbon Monoxide. By using RVT Group’s MONITEX^® P55 Hand-Held Gas Monitor, a number of gases were continuously monitored, alleviating risk of over-exposure as a visual and audible alarm would alert the workforce to any danger. This allowed Morgan Sindall to not only guarantee the health and safety or workers, but also prove compliance with COSHH regulations.

The fresh air and gas monitoring meant that works could continue as normal throughout the duration of the project.