4.12 SR 06-20-2022 - Laserfiche WebLink

Home Browse Search

Northwest Urban Service Expansion Study June 6, 2022 Page 2 Wastewater flows and water demands for the Northwest study area will be projected based on City-provided future land use zoning classifications and growth projections. Wastewater flows and water demands for the gravel mining area will be calculated based on the data available in the Gravel Mining Area Land Use, Transportation, and Utility Plan completed in 2015. Task 2.3 — Assess Sewer Infrastructure Needs: Assess the infrastructure needs for municipal sewer to serve the Northwest study area and the gravel mining area based on the existing wastewater flows (Task 2.1) and the projected wastewater flows (Task 2.2). The sanitary sewer analysis will include a recommendation for sizing and location of future trunk sewers and lift stations. Based on preliminary discussions with City staff, the existing sanitary sewer system cannot accept the additional wastewater generated in the Northwest study area. Therefore, a new regional lift station will be needed. The new regional lift station will be sized accordingly to also pump wastewater generated in the landfill and future redevelopment within the gravel mining area. Wastewater pumped by the regional lift station will be conveyed via forcemain to the one of the existing lift stations that City uses to pump wastewater into the City's wastewater treatment plant. Pump runtime data will be provided by City staff for the wastewater treatment plant's lift station to preliminarily evaluate the need to increase its pumping capacity as the Northwest study area develops. Task 2.4 — Assess Water Infrastructure Needs: Assess the infrastructure needs for water distribution system to serve the Northwest study area based on the existing water demands (Task 2.1) and the projected water demands (Task 2.2). The water distribution system analysis will include a recommendation for future water loop locations, sizing, and supplemental well and/or water storage, and any other associated details. WSB will utilize the City's existing water distribution system model to determine the static water pressures and available fire flows associated with the proposed trunk watermain layout. The need for pressure regulating stations will be evaluated using the water model. Task 2.5 — Conceptual Layouts: Conceptual trunk layouts will be provided for the sanitary sewer and water distribution systems. Trunk infrastructure will be sized appropriately to provide service to the future developments in the gravel mining area but conceptual layouts will only be provided to serve the future developments in the Northwest study area. Service options for the gravel mining area will not be shown in the layouts. Task 3: Financial Services Task 3.1 — Construction Costs: Prepare an Opinion of Probable Construction Costs for the proposed municipal water and sewer improvement alternatives. Task 3.2 — Financial Analysis: Complete a financial impact analysis to provide recommendations for assessments based on land use type for the Northwest study area. This analysis will include attending meetings, data gathering and analysis, reviewing and verifying programmed improvements, and developing potential new assessment amounts for the proposed development. Task 4: Report Preparation Prepare a draft report, including preliminary design layout(s) (GIS map figures) of the proposed water and sanitary sewer improvement alternatives, flow capacity and associated development acreage for each alternative, and conceptual level construction costs for each alternative. If these recommendations include trunk area assessments (or any private property assessments) the report