Sonora Regional Wastewater Treatment Facility Improvements Project Administrative Draft CEQA Initial Study/Mitigated Negative Declaration November 2019 Prepared for: Tuolumne Utilities District Prepared by: Stantec Consulting Services Inc. SONORA REGIONAL WASTEWATER TREATMENT FACILITY IMPROVEMENTS PROJECT CEQA INITIAL STUDY/MITIGATED NEGATIVE DECLARATION Table of Contents ABBREVIATIONS AND GLOSSARY ........................................................................................ V 1.0 INTRODUCTION ..........................................................................................................1.1 1.1 NEED FOR PROJECT ................................................................................................. 1.1 2.0 PROJECT DESCRIPTION ...........................................................................................2.1 2.1 HEADWORKS & SEPTAGE RECEIVING FACILITY IMPROVEMENTS ...................... 2.5 2.2 SECONDARY TREATMENT IMPROVEMENTS ..........................................................2.6 2.2.1 Upgrade the Process to Extended Aeration Activated Sludge Process ....... 2.6 2.3 DISINFECTION & FUTURE FILTRATION IMPROVEMENTS ......................................2.6 2.4 SLUDGE STABILIZATION AND DEWATERING IMPROVEMENTS ............................ 2.7 2.5 SRWWTF OPERATION AND MAINTENANCE ............................................................2.7 2.6 CONSTRUCTION ACTIVITIES AND ESTIMATED SCHEDULE ...................................2.7 2.7 CEQA PROCESS .........................................................................................................2.8 2.8 SCOPE OF THIS STUDY .............................................................................................2.8 3.0 ENVIRONMENTAL CHECKLIST FORM AND ANALYSIS .......................................... 3.1 3.1 AESTHETICS ...............................................................................................................3.2 3.1.1 Regulatory Setting ....................................................................................... 3.2 3.1.2 Environmental Setting ................................................................................. 3.2 3.1.3 Impact Analysis ........................................................................................... 3.3 3.1.4 Mitigation Measures .................................................................................... 3.5 3.2 AGRICULTURAL AND FORESTRY RESOURCES ......................................................3.5 3.2.1 Regulatory Setting ....................................................................................... 3.5 3.2.2 Environmental Setting ................................................................................. 3.7 3.2.3 Impact Analysis ........................................................................................... 3.7 3.2.4 Mitigation Measures .................................................................................... 3.9 3.3 AIR QUALITY .............................................................................................................3.10 3.3.1 Regulatory Setting ..................................................................................... 3.10 3.3.2 Environmental Setting ............................................................................... 3.12 3.3.3 Impact Analysis ......................................................................................... 3.13 3.3.4 Mitigation Measures .................................................................................. 3.17 3.4 BIOLOGICAL RESOURCES ......................................................................................3.18 3.4.1 Regulatory Setting ..................................................................................... 3.19 3.4.2 Environmental Setting ............................................................................... 3.24 3.4.3 Impact Analysis ......................................................................................... 3.34 3.4.4 Mitigation Measures .................................................................................. 3.39 3.5 CULTURAL AND TRIBAL CULTURAL RESOURCES ................................................ 3.41 3.5.1 Regulatory Setting ..................................................................................... 3.41 3.5.2 Environmental Setting ............................................................................... 3.45 3.5.3 Impact Analysis ......................................................................................... 3.50 3.5.4 Mitigation Measures .................................................................................. 3.54 3.6 ENERGY ....................................................................................................................3.58 3.6.1 Regulatory Setting ..................................................................................... 3.58 km rpt_tud_srwwtf_improvements_ceqa_admin_draft_11052019.docx i SONORA REGIONAL WASTEWATER TREATMENT FACILITY IMPROVEMENTS PROJECT CEQA INITIAL STUDY/MITIGATED NEGATIVE DECLARATION 3.6.2 Environmental Setting ............................................................................... 3.61 3.6.3 Impact Analysis ......................................................................................... 3.61 3.6.4 Mitigation Measures .................................................................................. 3.62 3.7 GEOLOGY AND SOILS .............................................................................................3.62 3.7.1 Regulatory Setting ..................................................................................... 3.62 3.7.2 Environmental Setting ............................................................................... 3.63 3.7.3 Impact Analysis ......................................................................................... 3.65 3.7.4 Mitigation Measures .................................................................................. 3.69 3.8 GREENHOUSE GASSES .......................................................................................... 3.70 3.8.1 Regulatory Setting ..................................................................................... 3.70 3.8.2 Environmental Setting ............................................................................... 3.72 3.8.3 Impact Analysis ......................................................................................... 3.72 3.8.4 Mitigation Measures .................................................................................. 3.74 3.9 HAZARDS AND HAZARDOUS MATERIALS ..............................................................3.74 3.9.1 Regulatory Setting ..................................................................................... 3.74 3.9.2 Environmental Setting ............................................................................... 3.76 3.9.3 Impact Analysis ......................................................................................... 3.77 3.9.4 Mitigation Measures .................................................................................. 3.80 3.10 HYDROLOGY AND WATER QUALITY ......................................................................3.83 3.10.1 Regulatory Setting ..................................................................................... 3.83 3.10.2 Environmental Setting ............................................................................... 3.84 3.10.3 Impact Analysis ......................................................................................... 3.85 3.10.4 Mitigation Measures .................................................................................. 3.89 3.11 LAND USE AND PLANNING ......................................................................................3.89 3.11.1 Regulatory Settings ................................................................................... 3.89 3.11.2 Environmental Setting ............................................................................... 3.90 3.11.3 Impact Analysis ......................................................................................... 3.90 3.11.4 Mitigation Measures .................................................................................. 3.91 3.12 MINERAL RESOURCES ............................................................................................ 3.91 3.12.1 Regulatory Setting ..................................................................................... 3.91 3.12.2 Environmental Setting ............................................................................... 3.92 3.12.3 Impact Analysis ......................................................................................... 3.93 3.12.4 Mitigation Measures .................................................................................. 3.93 3.13 NOISE ........................................................................................................................ 3.94 3.13.1 Regulatory Setting ..................................................................................... 3.94 3.13.2 Environmental Setting ............................................................................... 3.95 3.13.3 Impact Analysis ......................................................................................... 3.96 3.13.4 Mitigation Measures .................................................................................. 3.99 3.14 POPULATION AND HOUSING ...............................................................................