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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. Goal of Meeting. Provide information on Wastewater Collection Options Provide cost estimates
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Wastewater Collection Options forLakota Beach Area Sub-Basin Special Meeting June 27, 2001 John Bowman Lakehaven Utility District (253) 946-5401
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
Area of Interest DRAFT Lakota Beach Area Total Area: ~105 Acres Property Area: ~80 Acres Tax Lots: ~135
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
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
DRAFT Lakota Beach Area GRAVITY SEWER SYSTEM Pump Station Gravity Main Force Main
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
DRAFT Lakota Beach Area PRESSURE SEWER SYSTEM Pressure Main
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
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)
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
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
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
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
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
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
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
Example of Total Costs: Based on Area Charge: Total Infrastructure Cost / 80 Acres and assuming a 1/2 Acre Lot
Example of Total Costs: Based on Per Lot Charge: Total Infrastructure Cost / 135 Lots
How is a Project Started? • Utility Local Improvement District (ULID) • Petition • Resolution (special circumstances) • Developer Extension • Utility Project
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
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
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
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
Examples of Financing Costs (ULID Assessments): Based on Per Area Charge:
Examples of Initial Costs: Based on Area Charge And ULID Financing: Total Infrastructure Cost / 80 Acres and assuming a 1/2 Acre Lot
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
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
Area of Interest DRAFT Lakota Beach Area Total Area: ~105 Acres Property Area: ~80 Acres Tax Lots: ~135