Emergency Storm Sewer Repair - Boland & Portage Roundabout – Selge Construction Co., Inc.

Home Browse Search

S:\Public Works\Projects\Projects by Year\2021 Projects\121-050 Boland & Portage Roundabout - Storm Sewer Emergency Repair\1 - Admin\1 - BPW Documents\20210728_121-050 Emergency Sewer Repair Boland and Portage Roundabout_Memo to BPW.doc INTER-OFFICE MEMORANDUM DEPARTMENT OF PUBLIC WORKS DIVISION OF ENGINEERING TO: Anne Fuchs, Clerk Board of Public Works FROM: Sue Ellen Doudrick, PE SUBJECT: 121-050 Emergency Sewer Repair Boland and Portage Emergency Sewer Repair DATE: July 28, 2021 On 6/29/2021 following a large rain event, Sewer Dept was notified of a sinkhole in the roundabout at Boland and Portage. The sinkhole was approximately 10’x8’ wide and roughly 12’ deep. Sewer Department entered the adjacent manhole and discovered 12” wide gap in the 84” storm sewer. The sinkhole likely was brewing for some time and the recent rain exacerbated the issue. Luckily, the sinkhole was contained in the roundabout itself but was under the power lines. Due to the complexity of the work, a contractor was needed to perform the emergency repair. Rain was in the forecast, and we needed to act quickly to contain this sinkhole from expanding outside of the roundabout and potentially into travel lanes or creating more soil loss into the sewer and putting the manhole structure and other utilities at risk. The sinkhole is under power lines and is challenge to access. The work is beyond what our crews are capable of doing in that the sewer is 84” in diameter, depth of excavation, and safety. Rain was forecasted. We reached out to two contractors, R&R Excavating and Selge. Both contractors met onsite immediately. R&R wanted to investigate the sewer condition and issue further before providing an estimate. Selge was available to mobilize the following day to perform the repair and provided an estimate of $25k and indicated the cost may be more based on what they find out after inspecting. The other contractor was cautious to commit and did not provide a price. Description of work: Selge mobilized equipment on 6/30. The work included a repair from inside the 84” sewer using rebar and grout to fill the voids. The sinkhole was backfilled and the adjacent pipes and 84” storm sewer downstream of the sinkhole were inspected to make sure they were not impacted by the loss of material or filled with material. The Sewer Department coordinated and provided traffic control to save on costs. Work was completed by 7/1. Pictures of the project: