DONNER SUMMIT Public Utility District WastewaterWastewater FacilitiesFacilities PlanPlan May 2010 Prepared for Donner Summit Public Utility District 3875 Atherton Road Prepared by Rocklin, CA 95765 916.773.8100 TEL 916.773.8448 FAX www.ecologic-eng.com Contents Donner Summit Public Utility District - Wastewater Facilities Plan SECTION 1 INTRODUCTION ................................................................................................ 1-1 SECTION 2 EXECUTIVE SUMMARY .................................................................................... 2-1 2.1 Climate (Section 3).......................................................................................2-1 2.2 Wastewater Flows And Loads (Section 4) ...................................................2-1 2.3 Existing Facilities (Section 5).......................................................................2-1 2.4 Waste Discharge and Treatment Requirements (Section 6).........................2-7 2.5 Development and Screening of Alternatives (Section 7) .............................2-7 2.6 Influent Flow Equalization and Plant Headworks (Section 8) ...................2-10 2.7 Biological Treatment (Section 9)................................................................2-10 2.8 Tertiary Filtration (Section 10)...................................................................2-13 2.9 Effluent Disinfection (Section 11)..............................................................2-13 2.10 Emergency Storage and Irrigation Storage (Section 12) ............................2-15 2.11 Effluent Storage to Mitigate Biostimulation in the South Yuba River (Section 13).................................................................................................2-15 2.12 Effluent Irrigation Disposal (Section 14)....................................................2-17 2.13 Residual Solids Processing and Disposal (Section 15)...............................2-17 2.14 Preliminary Environmental Analysis (Section 16).....................................2-19 2.15 Selection and Description of the Apparent Best Project (Section 17)........2-19 SECTION 3 CLIMATE .......................................................................................................... 3-1 3.1 Ambient Temperatures ...............................................................................3-1 3.2 Precipitation................................................................................................3-1 SECTION 4 WASTEWATER FLOWS AND LOADS................................................................. 4-1 SECTION 5 EXISTING FACILITIES ...................................................................................... 5-1 5.1 Influent Flow Measurement, Sampling and Equalization Storage .............5-1 5.2 Headworks ..................................................................................................5-5 5.3 Biological Treatment ..................................................................................5-6 5.4 Effluent Filtration .......................................................................................5-7 5.5 Effluent Disinfection...................................................................................5-8 5.6 Emergency Storage and Pumping System ..................................................5-9 5.7 Chemical Feed Systems..............................................................................5-9 5.8 Outfall to the South Yuba River .................................................................5-9 5.9 Effluent Irrigation Facilities........................................................................5-9 5.10 Solids Handling Facilities.........................................................................5-10 May 2010 Donner Summit Public Utility District DONN09-004 i Wastewater Facilities Plan Contents SECTION 6 WASTE DISCHARGE AND TREATMENT REQUIREMENTS ................................ 6-1 SECTION 7 DEVELOPMENT AND SCREENING ALTERNATIVES .......................................... 7-1 SECTION 8 INFLUENT FLOW EQUALIZATION AND PLANT HEADWORKS ......................... 8-1 8.1 Equalization Storage Volume Requirements and Equalization Controls ......................................................................................................8-1 8.2 Economic Benefits of Equalization Storage ...............................................8-4 8.3 Equalization Storage Site and Configuration Analysis...............................8-6 8.3.1 Existing Equalization Storage Basin and Related Facilities .........8-6 8.3.2 New Facilities Alternatives...........................................................8-7 8.3.3 Proposed Equalization Features ....................................................8-8 8.3.4 Equalization and Headworks Alternative Cost Analysis ..............8-9 SECTION 9 BIOLOGICAL TREATMENT............................................................................... 9-1 9.1 Heat Transfer and Temperature management.............................................9-1 9.1.1 Heat Transfer and Temperatures With and Without Basin Covers ...........................................................................................9-2 9.1.2 Consideration of Providing Supplemental Heat..........................9-15 9.1.3 Recommended Heat Transfer and Temperature Management Improvements..............................................................................9-17 9.1.4 References Used for Heat Transfer and Temperature Calculations.................................................................................9-18 9.2 Biological Treatment Alternative analysis................................................9-18 9.2.1 Upgrade and Expand Existing Integrated Fixed Film Activated Sludge System ............................................................9-18 9.2.2 New Integrated Fixed Film Activated Sludge.............................9-20 9.2.3 Membrane Bioreactors................................................................9-24 9.2.4 Submerged Attached Growth......................................................9-35 9.2.5 Comparative Cost Analysis for the Biological Treatment Alternatives .................................................................................9-37 9.2.6 Process Design Comparisons Between the IFAS and MBR Alternatives .................................................................................9-37 9.3 Chemical Storage and Feed Systems Associated With Biological Treatment..................................................................................................9-40 9.3.1 Ammonia Storage and Feed System ...........................................9-41 9.3.2 Methanol (or Alternative Carbon Source) Storage and Feed System.........................................................................................9-43 9.3.3 Alkalinity Storage and Feed System...........................................9-43 SECTION 10 TERTIARY FILTRATION ................................................................................. 10-1 10.1 Existing Facilities .....................................................................................10-1 10.2 Filter System Capacity Assessment..........................................................10-1 10.3 Tertiary Filtration System Improvements.................................................10-2 10.3.1 Backwash Supply System ...........................................................10-2 10.3.2 Coagulation and Flocculation .....................................................10-3 May 2010 Donner Summit Public Utility District DONN09-004 ii Wastewater Facilities Plan Contents SECTION 11 EFFLUENT DISINFECTION.............................................................................. 11-1 11.1 Continued Use of Chlorine and Sulfur Dioxide .......................................11-1 11.1.1 Chlorine Feed Capacity Evaluation ............................................11-1 11.1.2 Chlorine Contact Basin Capacity Evaluation..............................11-2 11.1.3 Sulfur Dioxide Feed Capacity Evaluation ..................................11-2 11.1.4 Chlorine and Sulfur Dioxide Safety Issues and Uniform Fire Code Requirements.....................................................................11-2 11.1.5 Disinfection Byproducts .............................................................11-3 11.2 UV disinfection.........................................................................................11-3 11.3 Ozone Disinfection ...................................................................................11-7 11.3.1 General Description and Benefits of Ozonation .........................11-7 11.3.2 System Components....................................................................11-9 11.3.3 Design Criteria ..........................................................................11-10 11.3.4 Preliminary Ozone System Layout ...........................................11-11 11.4 Disinfection Alternative Cost Analysis ..................................................11-12 SECTION 12 EMERGENCY STORAGE AND IRRIGATION STORAGE .................................... 12-1 SECTION 13 EFFLUENT STORAGE TO MITIGATE BIOSTIMULATION IN THE SOUTH YUBA RIVER................................................................................................... 13-1 13.1 Background...............................................................................................13-1 13.2 The Need for and Sizing of Effluent Storage to Mitigate Biostimulation ..........................................................................................13-2