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Home My WebLink Aboutsunol-phase-1-wastewater-feasibility-presentation-5-19-21-1Scope of Study  Compile and review information on existing OWTS  Soil and site suitability evaluation  Sinbad Creek water quality sampling  Formulate range of alternatives for long-term OWTS management  Develop conceptual plans and preliminary cost estimates for community wastewater alternatives Impetus for the Study  Growing concerns about the condition and function of many aging OWTS  Physical constraints for OWTS, including small lots, steep slopes, proximity to creeks  OWTS regulatory challenges for home remodeling and additions  Designated and Potential “Areas of Concern” Field & Background Studies  County OWTS File Reviews  Questionnaire Survey  Individual Field Reviews  Sinbad Creek water quality sampling  Questa Engineering (June 2017, March 2018)  Alameda Creek Alliance (February, May 2017) Questionnaire Survey Results Typically 2 buildings, 3 to 4 bedrooms, 2 occupants Vast majority of OWTS 40+ years old < 20% have separate graywater system 2 to 5-yr septic tank pump-out frequency (75%) 50% have had OWTS inspection, mostly downtown area, few in Kilkare Woods Vast majority report no OWTS problems Problems noted: sluggish plumbing, roots, access risers, tank replacement, leachfield replacement Field Reviews Sampling Reach Exceedances Questa Sampling Exceedances ACA Sampling Total Exceedances Percent Exceedance Upstream Control 0 of 3 samples 0 of 10 samples 0 of 13 samples 0% Kilkare Woods 1 of 15 samples 2 of 20 samples 3 of 35 samples 9% Lower Kilkare Rd 1 of 9 samples 3 of 20 samples 4 of 29 samples 14% Downtown Sunol 3 of 9 samples 4 of 10 samples 7 of 19 samples 37% Sinbad Creek - Fecal Bacteria Exceedances Formulating Wastewater Alternatives  OWTS Options  Status Quo – individual responsibility for OWTS  Onsite Management District Approach – customized local standards; streamlined permitting; shared monitoring & maintenance; public financing opportunities Community System Options  Wastewater flow estimates for Sunol sub-areas  Identify potential community wastewater sites  Wastewater collection methods  Wastewater treatment technologies  Wastewater disposal site constraints & capacities Wastewater Management Alternatives #1 No Project – Status Quo #2 OWTS Management Program #3 Kilkare Woods Community System #4 Downtown Sunol Community System #5 Downtown-Lower Kilkare Rd Community System #6 Sunol Community-wide Wastewater System #7 Sewer Connection to Pleasanton Alternative #1 No Project/Status Quo  Individual property owners responsible for cost of permitting, maintenance and repair of OWTS  Permitting by ACDEH  Variances common needed, involving costly and lengthy process  Situations triggering OWTS upgrades, repairs and replacement :  Abatement of failed system or complaint  In connection with building improvements  Condition of sale at time of property transfer  Voluntary by property owner as needed OWTS Upgrade-Repair Challenges  Standard septic tank-leachfield options limited by small lots, steep slopes, stream and other setbacks  Advanced treatment with pressure dosing leachfields/drip dispersal commonly needed  Lengthy and costly variance approvals often required  House additions and ADUs difficult to obtain OWTS Upgrade Category Estimated Percentage of Total OWTS Number of OWTS Estimated Average Cost Contingency 20% Variance Total Cost Existing Code- Compliant OWTS 5% 12 0 0 0 0 Low Level of Upgrade 20% 49 $18,000 $3,600 $5,000 $26,600 Mid Level of Upgrade 25% 61 $37,000 $7,400 $10,000 $54,400 High Level of Upgrade 50% 121 $64,000 $12,800 $15,000 $91,800 Alternative #1 – Estimated Numbers and Costs of OWTS Upgrades Alternative #2 OWTS Management Program  Adoption of customized local standards and procedures, such as: Local geographic variances for streamlined approvals Application of innovative technologies Credit for greywater systems and high efficiency water conserving fixtures Streamlined site reviews, design and permitting process New site development, remodel and additions policies  Community-based oversight, maintenance & environmental monitoring  Facilitate development of cluster OWTS and off-site easements  Obtaining and facilitating public financing to support: OWTS management activities Loans and grants to individual OWTS owners Financing for construction of cluster systems Alternative #2 – Cont’d OWTS Management Program OWTS Upgrade Category Estimated Percentage of Total OWTS Number of OWTS Estimated Average Cost Total Cost Existing Code-Compliant OWTS 5% 12 0 0 Low Level of Upgrade 20% 49 $18,000 $900,000 Mid Level of Upgrade 25% 61 $37,000 $2,257,000 High Level of Upgrade 50% 121 $64,000 $7,744,000 Total 100% 244 $10,901,000 Average Estimated Cost per Parcel (for 244 parcels) $44,676 Alternative #2 – Estimated Numbers and Costs of OWTS Upgrades under Management District Land Use # of Parcels Unit Flow (gpd)* Level of Residential Participation 100% 75% 50% Downtown Sunol Residential 60 125 7,500 5,625 3,750 Multi-Family 3 500 1,500 1,500 1,500 Commercial & Industrial 8 - 4,500 4,500 4,500 School 1 1,500 1,500 1,500 1,500 Railroad (Restroom) 1 1,000 1,000 1,000 1,000 Downtown Sunol Sub-total 16,000 14,125 12,250 Lower Kilkare Road Residential 68 125 8,500 6,375 4,250 Commercial 1 500 500 500 500 Lower Kilkare Road Sub-total 9,000 6,875 4,750 Kilkare Woods Residential 102 125 12,750 9,625 6,375 KWA Clubhouse 1 50 50 50 50 Kilkare Woods Sub-total 12,800 9,675 6,425 Study Area Total 37,800 30,675 23,425 Estimated Community Wastewater Flows *gpd stands for gallons per day KWA Clubhouse Parcel (6.7 ac) Potential Area for Community Wastewater System (0.5 ac) Alternative 3 Kilkare Woods Community System Item Level of Residential Participation 3A - 100% 3B - 75% 3C - 50% Total Parcels (ESDs)* 103 78 52 Public Facilities Cost $2,476,000 $2,280,800 $2,070,400 On-lot Facilities Cost $1,876,200 $1,421,400 $951,600 Total Estimated Cost $4,352,200 $3,702,200 $3,022,000 Estimated Cost per Parcel (ESD) $42,254 $47,464 $58,115 Approximate Homeowner Cost for On-lot Work $5,000 $5,000 $5,000 Net Cost to Assessment per Parcel (ESD) $37,254 $42,464 $53,115 Annual Cost per Parcel (assume 20-years at 3%) $2,504 $2,854 $3,570 Preliminary Cost Estimate Kilkare Woods - Alternative 3 (A, B & C) *“ESD” stands for equivalent single family dwelling Bond St Service Yard 100’ 10,000 ft2 area for subsurface drip dispersal/irrigation 16,000 ft2 area for treatment, leachfields or drip dispersal (existing Cerny Bldg. leachfield) Depot Gardens 4,000 ft2 area for treatment or drip dispersal 12,000 ft2 area for treatment leachfields or drip dispersal 50’ Setback distance to top of creek bank Aternative #4 Downtown Sunol Community Wastewater System Subsurface Drip Dispersal-Irrigation Areas 3” dia. STEP sewers; each parcel has its own septic tank and pump unit Existing pipeline to Cerny Bldg. leachfield may be utilized Depot Gardens Primary leachfield & 100% reserve area Possible Future Public Restroom at RR Station Secondary Treatment at Depot Gardens (east end) or Bond St Yard Bond St Service Yard Item Level of Residential Participation 4A - 100% 4B - 75% 4C - 50% Total Parcels 73 58 43 Residential Parcels 60 45 30 Multi-family and Non-residential Parcels 13 13 13 Multi-family and Non-residential ESDs 39 39 39 Total Estimated ESDs 99 84 69 Public Facilities Cost $2,133,600 $1,960,800 $1,768,000 On-lot Facilities Cost $1,705,800 $1,372,800 $1,039,800 Total Estimated Cost $3,839,400 $3,333,600 $2,807,800 Estimated Cost per Residence (ESD) $38,782 $39,686 $40,693 Approximate Homeowner Cost for On-lot Work $5,000 $5,000 $5,000 Net Cost to Assessment per Parcel (ESD) $33,782 $34,686 $35,693 Estimated Annual Cost per Parcel (ESD) (assume 20 years at 3% interest) $2,270 $2,331 $2,400 Preliminary Cost Estimate Downtown Sunol - Alternative 4 (A, B & C) Alternative #5 Downtown Sunol & Lower Kilkare Road Community Wastewater System 3” & 4” dia. STEP/STEG sewers; each parcel has its own septic tank and pump unit or gravity connection to sewer Depot Gardens Secondary Treatment at Bond St Yard, or split between Bond St & Depot Gardens Bond St Service Yard Possible Future Public Restroom at RR Station 4” dia. STEP/STEG sewer extension on Kilkare Rd, approximately 2 miles Subsurface Drip Dispersal-Irrigation Areas Primary leachfield & 100% reserve area Existing pipeline to Cerny Bldg. leachfield may be utilized Item Level of Residential Participation 5A - 100% 5B - 75% 5C - 50% Total Parcels 142 110 78 Residential Parcels 128 96 64 Multi-family and Non-residential Parcels 14 14 14 Multi-family and Non-residential ESDs 42 42 42 Total Estimated ESDs 170 138 106 Public Facilities Cost $4,378,400 $4,050,400 $3,660,800 On-lot Facilities Cost $3,024,000 $2,379,000 $1,725,000 Total Estimated Cost $7,402,400 $6,429,400 $5,385,800 Estimated Cost per Residence (ESD) $43,544 $46,590 $50,809 Approximate Homeowner Cost for On-lot Work $5,000 $5,000 $5,000 Net Cost to Assessment per Parcel (ESD) $38,544 $41,590 $45,809 Estimated Annual Cost per Parcel (ESD) (assume 20 years at 3% interest) $2,590 $2,796 $3,080 Preliminary Cost Estimate Downtown & Lower Kilkare Rd - Alternative 5 (A, B & C) Item Level of Residential Participation 6A - 100% 6B - 75% 6C - 50% Total Parcels 245 187 130 Residential Parcels 231 174 116 Multi-family and Non-residential Parcels 14 14 14 Multi-family and Non-residential ESDs 42 42 42 Total Estimated ESDs 273 216 158 Public Facilities Cost $7,188,000 $6,572,000 $5,837,600 On-lot Facilities Cost $4,837,800 $3,732,900 $2,610,600 Total Estimated Cost $12,025,800 $10,304,900 $8,448,200 Estimated Cost per Residence (ESD) $44,051 $47,708 $53,470 Approximate Homeowner Cost for On-lot Work $5,000 $5,000 $5,000 Net Cost to Assessment per Parcel (ESD) $39,051 $42,708 $48,470 Estimated Annual Cost per Parcel (ESD) (assume 20 years at 3% interest) $2,625 $2,870 $3,258 Preliminary Cost Estimate Sunol Community-wide - Alternative 6 (A, B & C) Preliminary Cost Estimate Sewer Connection to Pleasanton – Alternative 7 Item Estimated Cost Public sewer facilities cost: $ 16,177,600 On-lot facilities connection cost: $ 3,119,400 Total estimated construction cost: $ 19,297,000 Construction cost per residence (273 ESDs): $ 70,945 City of Pleasanton connection fee per residence: $ 14,885 Total estimated cost per connection: $ 85,830 Up-front homeowner costs for connection: $ 27,000 Net Cost to Assessment per Parcel (ESD): $ 58,830 Estimated Annual Cost per Parcel (ESD): (assume 20 years at 3% interest) $ 3,934 Alternative # Parcels Served Estimated Project Cost Estimated Cost per ESD Estimated Amortized Cost #1 – No Project, Status Quo 244 N/A $27,000 to $92,000+ N/A #2 – Onsite Management District 244 $10,883,000 $18,000 to $64,000 Possible Financing #3 – Kilkare Woods System 103 $4,352,200 $42,254 $2,504 #4 – Downtown Sunol System 73 $3,839,400 $ 38,782 $2,270 #5 – Downtown & Lower Kilkare Rd 142 $7,402,400 $43,544 $2,590 #6 – Sunol Community-wide System 245 $ 12,025,800 $44,051 $2,625 # 7 – Sewer Connection to Pleasanton 245 $ 19,297,000 $ 85,830 $ 3,934 Preliminary Cost Summary Next Steps  Review and discuss information in the report  Community surveys on level of interest, preferences, additional information needs, etc.  Talk to or visit other similar communities  Define potential service areas  Define scope of additional studies  Funding sources  Phase 2 Feasiblity Study, if warranted