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

2. Introduction Sanitary District Feasibility Study Formation Powers
Purpose
Scope
Results

3. Sanitary District - Creation Wis. State Statute 60
Sanitary District - Creation Wis. State Statute 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

4. Sanitary District – Board of Commissioners Wis. State Statute 60
Sanitary District – Board of Commissioners Wis. State Statute 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

5. Sanitary District – Powers and Duties Wis. State Statute 60
Sanitary District – Powers and Duties Wis. State Statute 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

6. Sanitary District – Powers and Duties Wis. State Statute 60
Sanitary District – Powers and Duties Wis. State Statute 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

7. Sanitary District – Specific Powers Wis. State Statute 60
Sanitary District – Specific Powers Wis. State Statute 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

8. Sanitary District – Specific Powers Wis. State Statute 60
Sanitary District – Specific Powers Wis. State Statute 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

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

16. Pressure Sewer System
Residential Pump Station

17. 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.

18. 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.

19. 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

20. 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.

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

22. 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

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

24. 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

25. 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%

26. 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%)

27. 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

28. Questions?