The City and Borough of Sitka Municipal Sanitary Sewer Master Plan October 2012 Prepared by: G.V. Jones & Associates O’Neill Surveying & Engineering FCS Group Carson Dorn CITY AND BOROUGH OF SITKA MUNICIPAL SANITARY SEWER MASTER PLAN Prepared for: City and Borough of Sitka Department of Public Works 100 Lincoln Street Sitka, Alaska 99835 Prepared by: DOWL HKM 4041 B Street Anchorage, Alaska 99503 (907) 562-2000 W.O. 60854 October 2012 City and Borough of Sitka Sitka, Alaska Municipal Sanitary Sewer Master Plan October 2012 TABLE OF CONTENTS Page EXECUTIVE SUMMARY ............................................................................................................. I 1.0 INTRODUCTION ...............................................................................................................1 1.1 Existing Conditions ...........................................................................................................1 2.0 REGULATORY COMPLIANCE ANALYSIS ...................................................................3 2.1 Background .......................................................................................................................3 2.2 Wastewater Treatment Facilities.......................................................................................5 2.2.1 Secondary Treatment Facilities...................................................................................5 2.2.2 Water Quality Standard Regulations for Discharge to Water .....................................6 2.2.3 Marine Water Designation ..........................................................................................6 2.3 Mixing Zone Criteria ........................................................................................................7 2.4 Current Regulatory Permit Compliance............................................................................8 2.5 Wastewater Flows .............................................................................................................9 2.6 Wastewater Treatment Plant Performance ......................................................................11 2.7 Receiving Water Quality Compliance ............................................................................16 2.8 Monitoring Programs ......................................................................................................17 2.9 Future Regulatory Implications ......................................................................................17 2.9.1 Wet-Weather Flows ..................................................................................................18 2.9.2 Nutrients ....................................................................................................................19 2.9.3 Disinfection By-Products ..........................................................................................21 2.9.4 Pharmaceuticals and Endocrine Disruptors ..............................................................22 2.10 Implications for City and Borough of Sitka Wastewater Treatment ..............................22 3.0 CONDITION ASSESSMENT METHODOLOGY ...........................................................23 3.1 Review of Closed-Circuit Television Reports ................................................................24 3.2 Smoke Testing and Inflow and Infiltration Assessment .................................................28 4.0 CONDITION ASSESSMENT RECOMMENDATIONS .................................................29 4.1 Gravity and Sewer Force Main Recommendations ........................................................29 4.1.1 Anna Drive Basin Sewer Main (Basin 2) .................................................................29 4.1.2 Jamestown Drive Basin Sewer Main (Basin 3) ........................................................30 4.1.3 Wolff Drive Sewer Main (Basin 4) ...........................................................................31 4.1.4 Lance Drive Sewer Main (Basin 5) ..........................................................................32 4.1.5 Sawmill Creek Road at Jarvis Street Sewer Main (Basins 6 and 6A) ......................32 4.1.6 Price Street Sewer Main (Basin 6B) .........................................................................33 4.1.7 Sawmill Creek Road, Degroff Street at Park Street Sewer Mains (Basin 9) ............34 4.1.8 Baranoff Street Sewer Main (Basin 11) ....................................................................35 4.1.9 Degroff Street, Hollywood Way, Highland, Baranof, and Merrill Sewer Mains (Basin 12) .......................................................................................................35 4.1.10 Princess Way, Seward Street and Barracks Street Sewer Main (Basin 18) ..............36 4.1.11 Tlingit Way, Marine, and Seward Streets Sewer Main (Basin 19) ...........................37 4.1.12 Observatory, Seward, and American Street Sewer Main (Basin 20) ........................38 4.1.13 Lake Street, Hirst, Kincaid and Monastery Streets Sewer Mains (Basin 23) ...........38 4.1.14 Kimsham, Tilson, and Petersen Street Sewer Main (Basin 31) ................................40 4.1.15 Old Harbor Mountain Road Sewer Main (Basin 42) ................................................40 4.1.16 Viking Way and Valhalla Drive Sewer Main (Basin 47) .........................................41 4.1.17 Monastery Street Sewer Main (Sawmill Creek Road to DeGroff Street) (Basin 13) ..................................................................................................................41 4.1.18 Verstovia Street (Basin 24) .......................................................................................42 Page i City and Borough of Sitka Sitka, Alaska Municipal Sanitary Sewer Master Plan October 2012 TABLE OF CONTENTS (cont) Page 4.1.19 Verstovia Street (Basin 25) .......................................................................................42 4.1.20 Jeff Davis Street and Lincoln Street (Jeff Davis To Lake Street (Basin 10) ............43 4.1.21 Halibut Point Road Sewer Main ...............................................................................43 4.2 Inflow and Infiltration Improvements .............................................................................43 4.3 Lift Stations .....................................................................................................................44 4.3.1 Channel Lift Station ..................................................................................................44 4.3.2 Brady Lift Station .....................................................................................................45 4.3.3 Old Thomsen Harbor Lift Station .............................................................................45 4.3.4 Lake Street Lift Station .............................................................................................45 4.3.5 Jamestown Lift Station .............................................................................................45 4.3.6 East Jamestown Lift Station......................................................................................46 4.3.7 Crescent Lift Station .................................................................................................46 4.3.8 Lift Station Electrical and Supervisory Control and Data Acquisition Assessment Improvements........................................................................................46 4.4 Lift Station Capacity .......................................................................................................48 4.5 Future Developments ......................................................................................................50 4.6 Wastewater Treatment Recommendations .....................................................................52 4.6.1 Treated Wastewater Effluent Disinfection................................................................52 4.6.2 Biosolids Disposal Facility Upgrades .......................................................................56 4.6.3 Primary Effluent Heat Recovery ...............................................................................56 4.6.4 Leachate Treatment and Disposal .............................................................................57 5.0 CAPITAL IMPROVEMENT PROJECTS ........................................................................60 5.1 Short-Term (10-Year) Capital Improvement Programs ..................................................60 5.2 Long-Term Capital Improvement Projects .....................................................................66 5.2.1 Wastewater Secondary Treatment ............................................................................69 5.3 Cost Estimation Methodology ........................................................................................74 5.3.1 Collection System .....................................................................................................74 5.4 Wastewater Treatment Plant ...........................................................................................75 6.0 WASTEWATER SYSTEM FINANCIAL PROGRAM ...................................................76 6.1 Financial Policies ............................................................................................................77 6.1.1 Self-Supporting Enterprise Fund ..............................................................................77 6.1.2 Operating (Working Capital) Reserves .....................................................................79