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April 2016 - FINAL DRAFT 1-1 pw://Carollo/Documents/Client/CA/Modesto/9704A00 - WW Collection/Deliverables/CH01/Draft Final - Ch01 CS.docx Chapter 1 PROJECT BACKGROUND 1.0 INTRODUCTION The goal of the overall wastewater master planning effort is to define the City of Modesto's (City) approach in order to optimize its wastewater collection and treatment systems, provide flexibility for future conditions, improve system reliability, and maximize recycled water production. The planning effort will also set the foundation for a solid financial plan that fairly distributes costs to existing and new users of the systems and fully leverages alternative sources of funding. To reflect the view that each system is critical on its own and deserves detailed evaluation, the Wastewater Master Plan has been divided into two master plans: a Wastewater Collection System Master Plan and a Wastewater Treatment Master Plan. This chapter discusses the work of previous wastewater collection system master planning and provides an overview of the existing collection system and its associated infrastructure facilities. It also briefly describes each chapter in the Wastewater Collection System Master Plan. For more information, consult each individual chapter. 1.1 PREVIOUS MASTER PLAN The City's Wastewater Collection System Master Plan (2007 Plan) was last updated in 2007. This plan included a capacity evaluation of the City’s wastewater collection system, recommended improvements to mitigate capacity deficiencies within the collection system, a summary of capital costs associated with the recommended improvements, and a condition assessment of a sampling of the City’s collection system. Since completing the 2007 Plan, the City’s planning assumptions, infrastructure, and operational conditions have changed, creating the need for a new master plan. The assumptions used in this Master Plan are based on proposed changes to the City’s General Plan Land Use diagram. These changes were provided by City Planning staff and represent the direction of the General Plan update. They will be incorporated into a General Plan Amendment, which is currently being developed. In addition, it should be noted that the City is considering an alternative proposed land use diagram that was developed on July 11, 2014. The City asked Carollo to evaluate impacts to the wastewater collection system of the "alternative" land use diagram and include the results in an appendix to the Master Plan. As a result, Carollo summarized the results in Appendix A, which is included with this Master Plan. Should future planning conditions change from the assumptions stated in this Master Plan accelerated growth or more intense developments), revisions and adjustments to its recommendations would be necessary. ---PAGE BREAK--- April 2016 - FINAL DRAFT 1-2 pw://Carollo/Documents/Client/CA/Modesto/9704A00 - WW Collection/Deliverables/CH01/Draft Final - Ch01 CS.docx 1.2 WASTEWATER SERVICE AREA OVERVIEW The City’s Utilities Department owns and operates a wastewater collection system and its associated infrastructure facilities for customers within City limits, some unincorporated areas within the Modesto Municipal Sewer District #1 Service Area, and, by agreement, defined areas outside of the City's General Plan boundary. This system includes approximately 618 miles of active sanitary sewer lines ranging from 4 inches to 66 inches in diameter and 40 lift stations. Wastewater is also conveyed through approximately 32 miles of privately owned and neighboring agency sewer pipes to the City's collection system. Figure 1.1 illustrates the City’s existing sewer service area. Additionally, the City’s Wastewater Services Division operates two separate treatment facilities: a primary treatment facility located on Sutter Avenue (Sutter Plant) and secondary/tertiary treatment facilities located approximately seven miles away at the Jennings Plant. Also located at the Jennings Plant is the Modesto Ranch, a 2,540-acre agricultural property irrigated with treated municipal effluent and cannery process waters. The ranch also receives biosolids generated at the Sutter Plant. 1.3 AUTHORIZATION, PURPOSE AND SCOPE OF WORK This Master Plan has the following objectives: to identify capacity deficiencies within the wastewater collection system, to plan the infrastructure that will serve future development as projected by the City’s proposed General Plan Amendment, and to develop a capital improvement plan (CIP). On September 2, 2014, the City Council approved a professional service agreement with Carollo to prepare the Wastewater Master Plan. This agreement included the development of a Wastewater Collection System Master Plan and a Wastewater Treatment Master Plan. The Wastewater Collection System Master Plan included the following tasks: • Collect data and review background information. • Develop planning and system performance criteria. • Summarize the collection system condition assessment. • Summarize the results of flow monitoring. • Update wastewater flow development and projections. • Update the collection system hydraulic model. • Provide flow projections and analysis for the Cannery Segregation Line (CSL). • Perform collection system improvements analysis. • Develop an updated CIP. ---PAGE BREAK--- R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LSR7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LSR7 LS R7 LS R7 LS R7 LS R7 LS R7 LS R7 LS KIERNAN AVE COVERT RD BACON RD BECKWITH RD NORTH AVE WOODLAND AVE MAZE BLVD CALIFORNIA AVE PARADISE RD WHITMORE AVE SHOEMAKE AVE BLUE GUM AVE KANSAS AVE STODDARD RD AMERICAN AVE TULLY RD MC HENRY AVE COFFEE RD OAKDALE RD ROSELLE AVE CLAUS RD LANGWORTH RD CARVER RD DALE RD PRESCOTT RD FINNEY RD ALBERS RD HWY 99 HWY 99 HWY 99 BRIGGSMORE AVE 9TH ST SYLVAN AVE PELANDALE AVE BANGS AVE SAPTF R7 LS R7 LS R7 LS R7 LS R7 LS E:\KRC D DRIVE\Modesto\Figure 1.01 - Sewer Service Area.mxd SEWER SERVICE AREA FIGURE 1.1 CITY OF MODESTO WASTEWATER COLLECTION SYSTEM MASTER PLAN Legend Existing Collection System R7 LS Lift Station Collection System Pipelines 8" and Smaller 9" to 18" 20" to 36" Larger than 36" Sphere of Influence Study Area Modesto City Limits Roads North Ceres Service Area (To Modesto) Existing Service Area Future Service Area Sewer Service Area Existing Sewer Service Area Future Service Area O 0 1 2 Miles ---PAGE BREAK--- ---PAGE BREAK--- April 2016 - FINAL DRAFT 1-4 pw://Carollo/Documents/Client/CA/Modesto/9704A00 - WW Collection/Deliverables/CH01/Draft Final - Ch01 CS.docx 1.4 PLANNING PERIOD This Master Plan recommends several improvements to the City’s collection system infrastructure through the build-out of its Urban Area General Plan Sphere of Influence (SOI). These improvements include the construction of additional facilities within specific tributary areas of the wastewater service area to mitigate identified existing system deficiencies and respond to growth. Prioritizing these improvements will be based on development projections determined by City planners as well as needs identified from a condition assessment. 1.5 REPORT ORGANIZATION The Master Plan contains ten chapters followed by appendices that provide supporting documentation for the information presented in the report. The chapters are briefly described below. Chapter 1 – Project Background: This chapter provides background information for the 2015 Master Plan and explains why the plan is needed. Chapter 2 – Planning Area Characteristics: This chapter describes the study area, defines the land use classifications, and summarizes historical population trends. Chapter 3 – Flow Monitoring Program: This chapter describes the typical components of wastewater in a collection system and summarizes the temporary flow monitoring program data and results used for the study. Chapter 4 – Collection System Facilities and Hydraulic Model: This chapter presents an overview of the City's wastewater collection system and describes the update and calibration of its wastewater collection system hydraulic model. A detailed summary of the hydraulic model calibration steps, standards, and results for both dry and wet weather conditions is also provided. Chapter 5 – Planning Criteria and Design Flows: This chapter defines the planning criteria by which the capacity of the City’s wastewater collection system was evaluated. These criteria take into account the collection system capacity, the slopes of the gravity sewer pipes, and the maximum allowable flow depth within a sewer. The chapter also summarizes the existing and future design flows. Chapter 6 – Capacity Evaluation and Proposed Improvements: This chapter presents the results of a capacity evaluation of the wastewater collection system. It also details alternatives that will mitigate the existing system deficiencies and service future growth. These alternatives were determined by the system’s technical requirements, cost effectiveness, and operational reliability. ---PAGE BREAK--- April 2016 - FINAL DRAFT 1-5 pw://Carollo/Documents/Client/CA/Modesto/9704A00 - WW Collection/Deliverables/CH01/Draft Final - Ch01 CS.docx Chapter 7 – Cannery Segregation Line Evaluation: This chapter provides a summary of the cannery segregation line (CSL), including the physical characteristics of the trunk sewer and a description of the industrial customers that discharge into it. It also summarizes the results of the flow monitoring data collected from the CSL and the results of the CSL hydraulic capacity analysis. Chapter 8 – Condition Assessment and Rehabilitation and Reliability Improvements: This chapter summarizes the results from the City’s collection system condition assessment program and presents the recommended rehabilitation and reliability improvements based on the condition assessment results. Chapter 9 – Capital Improvement Program: This chapter presents the recommended Capital Improvement Program (CIP) for the City’s wastewater collection system, which is based on evaluations of the City’s sewer system and the recommended projects described in previous chapters. The CIP has been prepared to assist the City in planning and constructing the sewer system improvements through build-out of the General Plan. Chapter 10 – Capital Improvement Project Detail Summary Sheets: This chapter provides detailed summary sheets for the improvement projects described in Chapters 6 and 8.