T&I Completes ATEX Reassessment Study for Alexandria East WWTP

Back in 2016, an ATEX (explosive atmosphere) study on the Sludge Digestion facility at Alexandria East WWTP recommended a set of safety measures for the surrounding area — a precaution taken before the facility’s detailed design even existed. Nearly ten years, a full design, and years of live operation later, that recommendation had never been formally revisited against as-built conditions.

CAPW asked T&I to close that gap.

Over the past several months, our team:

• Reviewed the original 2016/2018 ATEX documentation and Environmental & Social Management Plans
• Carried out on-site inspections and operator interviews to verify as-built conditions
• Re-ran consequence modelling for all seven biogas hazard scenarios using the latest DNV Phast software

The result is a fully updated, as-built ATEX reassessment — giving CAPW and AFD a current, evidence-based picture to guide next steps, ten years on from the original study.

We presented the reassessment findings to CAPW and AFD representatives during a site visit to the facility on 19 July 2026, attended by the Chairman of the Alexandria Sanitary Drainage Company (ASDCo), the Deputy Minister of Housing for Utilities Affairs, the Deputy Head of the Project Management Unit (PMU), and a number of ASDCo’s senior leadership. The study was well received by CAPW and AFD, who offered constructive feedback during the session. Our thanks to both teams, and to the operator SUEZ, for their collaboration throughout this study.