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Wastewater Collection Options for Lakota Beach Area Sub-Basin Special Meeting June 27, 2001 John Bowman Lakehaven Utility District (253) 946-5401
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Goal of Meeting Provide information on Wastewater Collection Options Provide cost estimates Provide information on how a project can start and what it means to the property owners Answer Questions
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Area of Interest DRAFT Lakota Beach Area Total Area: ~105 Acres Property Area: ~80 Acres Tax Lots: ~135
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Wastewater Collection Options Gravity Sewer System Pressure Sewer System Others (not considered viable) –Vacuum Sewer System –STEP, Septic Tank Effluent Pumps –Small Diameter Gravity Cost Components: –Infrastructure (Utility Owned, Public Facility) –Private Facilities (Homeowner Owned) –Fees and Charges
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Gravity Sewer System Facilities Typical for most areas 4” Gravity Side Sewer pipe from Building to 6” Sewer Stub near property line (Private Facility) 6” Sewer Stub pipe from property to Gravity Main in street (Public Facility) Gravity Main flows to the treatment plant or a Central Pump Station that moves flows over hills through pressurized-mains toward the Treatment Plant For Lakota Beach Area, Central Pump Station is needed
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DRAFT Lakota Beach Area GRAVITY SEWER SYSTEM Pump Station Gravity Main Force Main
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Pressure Sewer System Alternative Sewer System (Low Pressure <50 psi) Short 4” Gravity flow from Building to Small Grinder Pump, usually near building (Private Facility) Pressurized slurry from Pump moves through a small 1-1/4” Side Sewer (Private Facility) to an equally sized Pressure Sewer Stub near the property line (Public Facility) Pressurized flow continues into pressure main ( Public Facility, usually 2” to 4” in diameter) in the Right-of-Way to a Gravity System or Treatment Plant For Lakota Beach Area, some to Treatment Plant, some to nearby gravity
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DRAFT Lakota Beach Area PRESSURE SEWER SYSTEM Pressure Main
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Has an Option been chosen for this Area? NO Typically new developments are required to provide gravity type service where available Alternatives are considered based on cost on environmental issues A selection will have to be made once a project is proposed
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Gravity Sewer System with Pump Station (for LBA) Pros –Most home would not have mechanical components for the home owners to maintain (some still need to pump) –If zoning densities increased, gravity systems typically have more inherent capacity for additional flow –Only Central Pump Station affected by power outages (on-site generator is assumed)
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Gravity Sewer System with Pump Station (for LBA) Cons –Generally higher cost to install in developed areas –Gravity Mains would be installed near center of road (probably need to rebuild roads) –Gravity Mains would be installed from 6 feet to 18 feet in depth, Pump Station about 20-25 feet deep –More disruptive to traffic and access –8” Minimum Size (DOE Standard) –About 25 homes will still need to pump to gravity main –Pump Station must account for Inflow and Infiltration potential
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Pressure Sewer System (for LBA) Pros –Less expensive to construct –Pressure Mains could be installed on the side of roads (avoiding significant road work) –Pressure Mains smaller (2”- 4”), installed at about 4 feet in depth –No Central Pump Station –Less disruptive to traffic and access –Lower potential for Inflow and Infiltration
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Pressure Sewer System (for LBA) Cons –All homes would have individual pumps to maintain –If zoning densities increased, pressure systems typically have less inherent capacity for additional flow –Individual home owners affected by power outages –Size of the mains is more critical. Need to maintain a 2 f/s velocity to keep solids from settling out
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Infrastructure Costs Gravity Sewer System –Estimated Cost: $1,860,000 Pump Station w/Force Main Gravity Mains and Stubs to properties Road Restoration Pressure Sewer System –Estimated Cost: $ 568,000 Pressure main and stubs w/restoration
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Private Facility Costs Gravity Sewer System –Estimated Cost: $2900 (Range $2000-10,000) Assumes 120’ of 4” pipe @ 20$/ft Septic Tank Abandonment @ $500 Pressure Sewer System –Estimated Cost: $5900 (Range $4000-8000) Assumes 120’ of 1-1/4” pipe @ 10$/ft Grinder Pump installed @ $4200 Septic Tank Abandonment @ $500
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Connection Fees Gravity Sewer System –Estimated Cost: $2865 Capital Facility Charge $2720 Side Sewer Permit $145 Pressure Sewer System –Estimated Cost: $3040 Capital Facility Charge $2720 Side Sewer Permit $145 Private Pump Agreement $195
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How are these costs paid? Infrastructure Costs is typically distributed equitably to property owners by either: Front footage Per Lot Per Area or Zone and Terminus Private Facilities Costs belong to individual properties Connection Fees are uniform, unless there are more than one residential unit per property
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Based on Area Charge: Total Infrastructure Cost / 80 Acres and assuming a 1/2 Acre Lot Example of Total Costs:
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Based on Per Lot Charge: Total Infrastructure Cost / 135 Lots Example of Total Costs:
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How is a Project Started? Utility Local Improvement District (ULID) –Petition –Resolution (special circumstances) Developer Extension Utility Project
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ULID One or more customers express interest for sewers in a particular area IF there appears to be sufficient interest (51% or more by land ownership), petitions are prepared (estimated costs) IF the minimum of 51% of the land owner sign in favor of the formation, the Board may Certify the petitions and authorize preliminary design
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ULID (continued) Formation Hearing (new cost estimates and boundaries may be redefined as a result) IF there is still support for the ULID, the Board can certify the ULID formation (Protest can still be filed) Project is designed and Bid - ONLY PUBLIC FACILITIES Financing will be reviewed (new cost estimates) and Construction begins
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ULID (continued) Final Costs are known and assessed Assessment Roll Hearing (Protest can be filed and allocation method can be revised) Legal notice of Assessment (appealable through supreme court) Assessments filed with County Treasurer for collections Assessments begin one year later and continue for 20 year
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ULID (continued) Once Public Facilities are in place, Billing for Sewer service begin, every two months (regardless of whether properties have connected) Time Frame for ULID Process –Past experience: 1-1/2 to 3 years –Pressure Option may be on the shorter side –Gravity Option maybe on the longer side
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Examples of Financing Costs (ULID Assessments): Based on Per Area Charge:
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Based on Area Charge And ULID Financing: Total Infrastructure Cost / 80 Acres and assuming a 1/2 Acre Lot Examples of Initial Costs:
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Developer Extension If a large property subdivides to sufficient density to preclude septic system and needs sewer, the development could build a portion of the infrastructure. Latecomer Charges could be allocated to neighboring properties for the portion of the infrastructure that would benefit them Latecomer Charges are paid at the time of connection
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Utility Project If there is benefit to the District as a whole to install sewers in advance, the District could do so. Not typical Examples: –Financial - increase customer base –Environmental benefits –Opportunity costs (minimize future installation costs) prior to new road combination with other projects
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Area of Interest DRAFT Lakota Beach Area Total Area: ~105 Acres Property Area: ~80 Acres Tax Lots: ~135
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