Mt. Lemmon Service Area Watershed Study & Wastewater Management Plan (Project No. 206145) TABLE OF CONTENTS EXECUTIVE SUMMARY........................................................................................................................III 1.0 BACKGROUND ...........................................................................................................................23 note: Section 1 for this final report starts on page 40. It has been purposely numbered starting at page 23 to be consistent with the 98% draft and prevent re-printing of the entire document. 1.1 PROJECT OVERVIEW................................................................................................................... 23 1.2 MT. LEMMON WASTEWATER HISTORY ...................................................................................... 25 1.3 COLLECTION SYSTEM OVERVIEW .............................................................................................. 31 1.4 TREATMENT FACILITY OVERVIEW ............................................................................................. 33 1.5 EFFLUENT DISPOSAL SYSTEM OVERVIEW.................................................................................. 34 2.0 PHYSICAL ENVIRONMENT ....................................................................................................36 2.1 FLOW VOLUMES......................................................................................................................... 36 2.2 ON-SITE WASTEWATER TREATMENT SYSTEMS.......................................................................... 45 2.3 ENVIRONMENTAL AND WILDLIFE ISSUES ................................................................................... 56 2.4 WATER RESOURCES ................................................................................................................... 83 2.5 WATERSHED FEATURES (SURFACE WATER) ............................................................................ 107 3.0 REGULATORY ISSUES ...........................................................................................................139 3.1 USFS SPECIAL USE PERMIT, NEPA AND IMPACT ON OPTION FEASIBILITY ............................. 154 3.2 AQUIFER PROTECTION PERMIT PROGRAM & IMPACT ON OPTION FEASIBILITY........................ 159 3.3 AZPDES REQUIREMENTS & IMPACT ON OPTION FEASIBILITY ................................................ 164 3.4 OTHER RELEVANT REGULATORY PROGRAMS AND IMPACT ON OPTIONS ................................. 175 3.5 COMPLIANCE AND ENFORCEMENT HISTORY & IMPACT ON OPTION FEASIBILITY .................... 183 3.6 COUNTY PERMITTING AUTHORITY, REQUIREMENTS AND OPTIONS ......................................... 187 3.7 RECOMMENDATIONS ................................................................................................................ 189 4.0 FINANCIAL ISSUES .................................................................................................................196 4.1 BOND FUNDING (CAPITAL)....................................................................................................... 196 4.2 OTHER FINANCING CAPACITIES ............................................................................................... 197 4.3 EFFLUENT ASSET VALUE ......................................................................................................... 201 4.4 BIOSOLID DISPOSAL COSTS...................................................................................................... 204 4.5 SYSTEM OPERATION AND MAINTENANCE COSTS..................................................................... 207 5.0 TECHNICAL ISSUES................................................................................................................209 5.1 CONVEYANCE TECHNOLOGIES................................................................................................. 214 5.2 TREATMENT TECHNOLOGIES.................................................................................................... 225 5.3 DISPOSAL TECHNOLOGIES........................................................................................................ 258 6.0 ECOLOGICAL ISSUES ............................................................................................................275 6.1 “SKY ISLAND” FACTORS .......................................................................................................... 275 6.2 WATER NEEDS ......................................................................................................................... 276 6.3 WATERSHED BALANCE ............................................................................................................ 277 6.4 RECREATIONAL USE................................................................................................................. 281 7.0 EMERGING CONDITIONS .....................................................................................................282 7.1 GROWTH .................................................................................................................................. 282 7.2 LAND USE ................................................................................................................................ 288 7.3 QUALITY .................................................................................................................................. 290 i 05/10/08 Mt. Lemmon Service Area Watershed Study & Wastewater Management Plan (Project No. 206145) 8.0 MANAGEMENT ISSUES..........................................................................................................292 8.1 PUBLIC INVOLVEMENT............................................................................................................. 292 8.2 REVISED USFS PERMIT............................................................................................................ 298 8.3 SERVICE AREA BOUNDARIES ................................................................................................... 299 8.4 FACILITY FEATURES (LOCATION, SIZE, TYPE) ......................................................................... 300 8.5 DISCHARGE/DISPOSAL METHOD(S).......................................................................................... 301 8.6 RECLAIMED (REUSE) OPTIONS ................................................................................................. 306 8.7 FLOW PROJECTIONS ................................................................................................................. 313 8.8 DEMAND MANAGEMENT.......................................................................................................... 318 9.0 CAPITAL IMPROVEMENT PLAN.........................................................................................319 9.1 SERVICE CONVEYANCE SYSTEM .............................................................................................. 319 9.2 WASTEWATER TREATMENT/RECLAMATION FACILITY............................................................. 320 9.3 EFFLUENT DISCHARGE AND RECLAIMED SYSTEMS.................................................................. 320 9.4 BIOSOLIDS DISPOSAL ............................................................................................................... 320 9.5 EVALUATION OF CONCEPTS ..................................................................................................... 321 9.6 PLAN IMPLEMENTATION SCHEDULE......................................................................................... 321 10.0 FINDINGS AND RECOMMENDATIONS..............................................................................325 ii 05/10/08 Mt. Lemmon Service Area Watershed Study & Wastewater Management Plan (Project No. 206145) EXECUTIVE SUMMARY In 2003, the Aspen Fire resulted in a large percentage of lost structures in the community of Summerhaven on Mount Lemmon. As the community recovers from the fire and begins redevelopment, future wastewater management is an important consideration. On May 18, 2004 Pima County residents passed a sewer bond package for the Mount Lemmon Wastewater Treatment Facility. The $7.2 million bond was funded to provide improvement and expansion options for the Mount Lemmon Wastewater Treatment Facility (WWTF), collection system, and the related effluent disposal system. In 2006, Pima County Wastewater Management Department (PCWMD), recently renamed Pima County Regional Wastewater Reclamation Department, initiated a study of the Mount Lemmon wastewater management system, options and the watershed in which Summerhaven is located. A set of objectives for a comprehensive study were developed with input from local representatives of the United States Forest Service (USFS), Pima County Department of Environmental Quality (PDEQ) and PCWMD. The USFS had received comments from stakeholders regarding disposal of wastewater from the WWTF. The WWTF currently receives wastewater from water sources in the Upper Sabino Creek Watershed. The treated effluent is piped to outfalls (end of pipe discharge) and a spray field that are located north of Summerhaven for disposal in the Alder Creek Watershed, which is tributary to the San Pedro Watershed. The 10-acre spray field disposal area is located on federal land within the Coronado National Forest and is regulated by a USFS Special Use Permit (SUP). Treated effluent is disposed in this spray field rather than being put to beneficial use. iii 05/10/08 Mt. Lemmon Service Area Watershed Study & Wastewater Management