As City Council is aware, this planned rehabilitation project is part of the ongoing preventative maintenance program at the WWTP. This project included the sealing of joint cracks in the plant’s sand filter tank two (2) that has approximately 1.270 million gallons flowing through it daily of partially treated effluent. This filtering process applies constant pressure pushing out on the existing seams which in turn, requires frequent proactive inspections to determine the condition of the existing rubber seals and concrete material.
During the project, several areas of concrete spalling was identified along the expansion joints. Spalling is a type of damage that affects concrete surfaces and structures. It is characterized by the flaking or chipping of the concrete surface, which can range from minor cosmetic issues to major structural problems. The term “spall” is used to describe the breaking up of a material into fragments, often due to subsurface fissures that cause a portion of the surface to peel away. Spalling can compromise the structural integrity of a building and pose safety risks if not addressed. Therefore, it is important to identify and repair spalling as soon as it is detected.
In an effort to remediate the spalling, a change order to the project was submitted to staff by the contractor. Subsequent to staffs review and the engineer’s review, it was determined to proceed with the remediation process due to the critical nature of the of the spalling. In addition, it should be noted that mobilization was not included and that the linear feet charge was within the industry standard for this type of repair.