The Sharon Sanitary Authority experienced a collapse of the media and support systems in two trickling filter units at the wastewater treatment plant, triggering an emergency situation. The units were approximately ten years old, well under the intended design life of the media and media support systems. With an unexpected material failure, the Authority needed to identify the cause of the collapse, as well as a solution to remedy the situation quickly and avoid the possibility of violating their National Pollutant Discharge Elimination System permit.
The Authority was familiar with RETTEW’s work for a neighboring Authority and asked us to conduct an assessment and provide a report of the findings. The Authority provided copies of construction plans and specifications, shop drawings, job conference records, post-failure notes and photos, and samples of failed units and materials removed from the units. RETTEW conducted a thorough investigation and presented a report containing our engineer’s opinion as to the cause of the failure, the extent of the damage, and recommendations for repairs. RETTEW’s report identified a significant design flaw in the media support system and provided guidance to the Authority on potential repairs and their costs. RETTEW worked with the Authority to expedite the trickling filter repair and assist in evaluating the legal and technical impacts of the failure.