Feasibility of Bass Lake Wastewater Treatment Prepared by Stantec Consulting Services June 2017

Introduction Sanitary District Feasibility Study Formation Powers Purpose Scope Results

Sanitary District - Creation Wis. State Statute 60 Sanitary District - Creation Wis. State Statute 60.70 Town Sanitary Districts Town Board has authority to establish a Sanitary District If the Sanitary District is in more than 1 Town, the Town with the greatest equalized value has “exclusive jurisdiction to establish the Town Sanitary District” Or, by petition of 51% of persons owning land or 51% of land mass owners DNR may order creation of a Sanitary District DNR would designate which properties to be included Town Board may then order the establishment, if not, the DNR would establish the boundaries

Sanitary District – Board of Commissioners Wis. State Statute 60 Sanitary District – Board of Commissioners Wis. State Statute 60.70 Town Sanitary Districts Three Commissioners, each a 2 year term, would be appointed by the Town Board (Term length would later change) May be appointed or elected If elected, election would be in April If elected the Town Board may not change back to appointed except by a referendum Must be residents of the Sanitary District

Sanitary District – Powers and Duties Wis. State Statute 60 Sanitary District – Powers and Duties Wis. State Statute 60.70 Town Sanitary Districts Commission has charge of all affairs of the Sanitary District May sue or be sued May enter into contracts Compensation set by Town Board

Sanitary District – Powers and Duties Wis. State Statute 60 Sanitary District – Powers and Duties Wis. State Statute 60.70 Town Sanitary Districts Commission may project, plan, construct and maintain: Water System Solid Waste Collection Sewage System Drainage Improvements Sanitary, Surface, and Storm Water Sewers

Sanitary District – Specific Powers Wis. State Statute 60 Sanitary District – Specific Powers Wis. State Statute 60.70 Town Sanitary Districts Sanitary District may: Sell any of its service to users outside of corporate limits Require installation of Private Onsite Wastewater Treatment Systems (POWTS) Require inspection of POWTS Provide direct financial assistance Issue orders Fix and collect charges

Sanitary District – Specific Powers Wis. State Statute 60 Sanitary District – Specific Powers Wis. State Statute 60.70 Town Sanitary Districts Sanitary District may: Levy Special Assessments Lease or acquire property Sell or dispose of property Enact Ordinances Let contracts for work Borrow money and issue Municipal obligations

Rehabilitation District Sanitary District Wis. State Statute 33 Rehabilitation District Sanitary District Wis. State Statute 33.22(3)(a) Sanitary Districts May have the power of a town sanitary district if: By authorizing resolution of a Town Board having the largest equalized value portion of the Sanitary District Shall possess the powers of the Town Sanitary District that are authorized by resolution by the Annual Meeting of the Rehabilitation District

Feasibility Study Reason: MnDOT Mitigation Funds available Purpose: investigate costs of centralized wastewater collection and treatment options Examined existing conditions Analyzed two collection options and three treatment alternatives

Existing Conditions Topography varies greatly Groundwater generally moves from east to west Bass Lake is an Outstanding Resource Water (ORW) Total phosphorous in lake has been gradually increasing Highway 64 bridge may increase development

Existing Conditions 215 homes near Bass Lake, 129 are within “shore zone” Project could be constructed in three phases 85 homes in Phase 1, 22 in Phase 2, 22 in Phase 3 Homes beyond the shore zone could be served in the future

Wastewater Flows Normal, domestic strength wastewater Parameter Phase 1 Phase 2 Phase 3 Total Average Flow, gpd 13,000 3,500 20,000 Wet Weather Flow, gpd 14,500 3,750 22,000 Peak Hour Flow, gpm 40 10 60 Normal, domestic strength wastewater No commercial or industrial wastewater

Collection System Two options: conventional gravity sewer or pressure sewer system. A pressure system would be more cost effective due to: Varied topography Some homes near the lake at low elevation Distance from homes to road

Pressure Sewer System Small diameter pressure piping 1 ¼” to 4” diameter Individual grinder pump station at each home

Pressure Sewer System Residential Pump Station

Effluent Limits Bass Lake and the St. Croix River are Outstanding Resource Waters (ORW) Fewer than 1% of Wisconsin’s waters are ORWs. Requested effluent limits for Willow River, Apple River, St Croix River from Wisconsin DNR Effluent limits are prohibitively stringent for surface waters Discharge to nearby surface waters is not a feasible option.

Treatment Alternatives Three options: Conveyance to Somerset WWTF Conveyance to New Richmond WWTF Construct a new wastewater treatment facility For all three options, the collection system cost remains the same.

Conveyance to Neighboring Town Collection system would discharge to a main pump station. Somerset would require about 6.5 miles of forcemain New Richmond would require about 7 miles of forcemain Both neighboring WWTFs capable of treating additional flows from Bass Lake area

Construct New WWTF Proposed facility would utilize a membrane bio reactor (MBR) process Combines proven biological process with membrane filtration The facility would discharge high quality effluent into three infiltration basins.

Construct New WWTF Facility would require approximately 4 to 5 acres This option would require further geotechnical investigation Must obtain discharge permit from WDNR

Operations, Constructability, and Implementation Collection System Part time operator Need permission, easements on each property Treatment Options Conveyance Disturbs large area Highway & railroad crossings Agreement with city New WWTF Facility Ownership Maintenance and repair Hauling biosolids

Cost Estimates Phase 1 Phase 2 Phase 3 Collection $3.0 million

Cost Estimates Conveyance to Somerset Conveyance to New Richmond Construct New WWTF Collection $4.9 million Treatment $4.7 million $5.2 million $1.7 million Total Capital $9.6 million $10.1 million $6.6 million Annual O,M&R $165,000 $120,000 Estimates include all three phases

Cost Per Household Collection and New WWTF Total Capital $6,600,000 Annual Debt Service* $303,000 Annual O,M & R $120,000 Total Annual Cost $423,000 Cost per Household $3,300/year *Based on 40-year loan at $3.375%

Funding Wisconsin DNR Clean Water Funding Program USDA Hardship Assistance – median household income too high Small Loans Program – Limited to projects <$2 Million Pilot Project Program – NA, meant for innovative treatment USDA Grants – not eligible, median household income too high Loan – 40 year repayment (current rate 3.375%)

Summary Purpose: Investigate feasibility and estimate costs for WW collection and treatment Pressurized collection system more cost effective than conventional Constructing and owning a WWTF has the lowest cost of the options evaluated A centralized wastewater treatment system will help protect Bass Lake’s high water quality for fishing, wildlife, and recreation

Questions?