Barr performed a National Association of Sewer Service Companies (NASSCO) inspection, assisted with design, and provided construction oversight services for rehabilitation of the St. Mary’s tunnel. Our inspection involved assessing the tunnel’s condition and repair needs. The design, plans, and specifications we developed were used for contact and backfill grouting, crack sealing, and surface and invert repair along a 1,700-foot-long section of the tunnel.
As part of Barr’s full-time construction management services, we conducted daily observations, documentation, and submittal review for the city. Our estimates on grout quantity, based on pre-drilled void measurements, were consistent with the actual volume of grout used during construction. This helped control costs during construction, allowing the work to be completed within the city’s budget.