Specifications include, but are not limited to: This Project is part of the Sanitary Sewer Relief Program. The intent of this ongoing Program is to review and manage the capacity of Phoenix’s wastewater collection system to avoid sanitary sewer overflows. Managing capacity is a basic tenet of the City’s Capacity Management, Operations, and Maintenance Program. The primary trigger for identifying capacity concerns is when the City’s sanitary sewer model indicates that sewer segments are flowing at or above 80 percent of the maximum capacity during peak dry weather conditions. Sewers in this Program are “bottle necks” in the Wastewater Collection System and are the first to showup with capacity problems. Increased capacity is provided by installing new parallel sewers or larger replacement sewers. In some cases, diversions can be constructed to re-route wastewater flows into other sewers that have more excess capacity. If flows increase in the future, segments upstream anddownstream may reach the 80 percent trigger point and need to be added into the Program. The Modeling Group identified the need for a relief sewer project in the area along Sweetwater Avenue from 23rd Avenue to 15th Avenue. The trunk sewer model calibrated with 2017 flows showed that several sewer segments in this area are at or exceeding a flow depth-to-diameter ratio (d/D) of 75%. As a result,the City will be designing and constructing a relief sewer project for this area.SECTION II – SCOPE OF WORK•Work includes replacement of approximately 5,000 linear feet of existing 12-inch sewer with new15-inch and 18-inch sewer from 23rd Avenue to 15th Avenue.•Conduct an alignment study for the relief sewer project described above.•Present the recommended alignment results to the City for discussion and selection.• Perform a sewer capacity analysis.•Determination of and assistance in obtaining any required easements and licenses.• Coordinate with the City of Phoenix Real Estate Division as necessary.• Perform data collection and field survey as necessary.•Perform utility investigations and coordination to prevent conflicts with final design.• Perform detailed geotechnical investigations including corrosion of potential soils.•Provide public information services based on Project impacts.•Prepare design concept report and design documents including technical specifications, special provisions, and drawings for constructing the relief sewer project.• Prepare preliminary and final construction cost estimates.• Prepare project schedules and hold progress meetings and workshops as needed to complete the work.• Coordinate with the City of Phoenix Street Transportation Department and other outside agencies as necessary.
