Agenda - Public Works Committee - 10/16/2018

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The storm sewer system consists of openings in the bituminous curb at the north end of the Ferret Street cul-de-sac and the east end of the 146th Avenue cul-de-sac. Utility easements exist north of Ferret Street and along the northern boundary of the eastern Ferret Street cul-de-sac which has shallow ditches leading towards Armstrong Boulevard. Stormwater runoff from 147th Avenue is collected in catch basins installed with the 2012 Sunwood Drive re -alignment project, and is directed under Armstrong Boulevard via storm sewer to existing regional ponds east of Armstrong Boulevard. The existing bituminous pavement section ranges from 1.6 to 6.1 inches thick, with an average thickness of 2.9 inches, and the aggregate base ranges from 4.3 to 15.5 inches thick, with an average thickness of 9.7 inches. Pavement section thicknesses were determined using data collected by Braun Intertec in 2017 via Ground Penetrating Radar (GPR), as well as from field observations and record plan documents. Copies of Braun Intertec's GPR results are included in Appendix C of the attached draft Feasibility Report. The pavement section was built on sandy subgrade material generally considered suitable for pavement support. City staff annually evaluates and rates the condition of pavement sections on all City streets using the Pavement Surface Evaluation and Rating (PASER) system. In the summer of 2017, the pavement section of the above referenced street segments were rated with a PASER rating of 2, indicating these streets require complete reconstruction. City staff patch these streets at least once per year, particularly before winter so the streets can be plowed without further damaging the pavement. Pictures of the streets are located inAppendix A of the attached Draft Feasibility Report. On July 11, 2017, the City Council adopted Resolution #17-07-170 ordering preparation of a Feasibility Report for the reconstruction of streets in HY-10 Ramsey. These streets were originally included in the City's CIP as proposed 2015 overlay improvements. However, the overlay work was delayed when construction of the Highway 10 & Armstrong Boulevard Interchange was funded. Following completion of the Interchange, the pavement was re-evaluated and Staff determined the pavement was no longer viable for overlay improvements and instead required reconstruction. This project is now included in the current 10-year CIP as a reconstruction project. When the City Council ordered the Feasibility Report, Staff was directed to review the existing streets in HY-10 Ramsey and explore whether the streets should be reconstructed in the same locations, or whether it might make sense to realign or extend one or more of the streets to better serve existing properties and/or to connect to Bunker Lake Industrial Park. Minutes from the July 11, 2017 City Council meeting are attached for reference. Staff explored numerous alternative street alignments and/or extensions. In May of 2018, the Development Review Committee (DRC), which consists of Staff from various departments, reviewed several design alternatives and recommended the following. Reconstruct all streets in their current footprints using pavement sections similar to the existing sections. Also, replace all existing bituminous curb on 146th Avenue and Ferret Street. Lastly, since 147th Avenue will likely not be modified during redevelopment, the existing watermain should be extended to the west end of 147th Avenue, and concrete curb and gutter should be constructed along both sides of 147th Avenue to Ferret Street. Due to the uncertainty of future development/redevelopment scenarios, Staff determined there are too many unknowns to justify the expense of realigning or extending streets at this time. The Feasibility Report proposes to reconstruct the existing bituminous pavement section using the Full Depth Reclamation (FDR) process which involves reclaiming (grinding and mixing) the existing bituminous pavement with an inch or more of existing aggregate base material. A portion of this reclaimed material is proposed to be spread and compacted on top of the reshaped and compacted existing subgrade/aggregate base. Three and one-half inches of bituminous pavement is then proposed to be installed on top of a minimum of 6 inches of aggregate base (existing aggregate base/reclaim material). This pavement section would generally match the existing pavement section on these streets, and would meet the City of Ramsey's minimum standard pavement design. Though the design strength of the proposed pavement section may be slightly less than a typical industrial park pavement section, Staff believes it will provide a useful life of at least 30 years based on the life achieved by the existing pavement section. Staff also believes there is a potential for this development to redevelop within the next 10 to 20 years, resulting in the potential realignment of streets.