ENVIRONMENTAL ASSESSMENT WORKSHEET

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2 ENVIRONMENTAL ASSESSMENT WORKSHEET Note to reviewers: The Environmental Assessment (EAW) provides information about a project that may have the potential for significant environmental effects. This EAW was prepared by the Minnesota Pollution Control Agency (MPCA), acting as the Responsible Governmental Unit (RGU), to determine whether an Environmental Impact Statement (EIS) should be prepared. The project proposer supplied reasonably accessible data for, but did not complete the final worksheet. Comments on the EAW must be submitted to the MPCA during the 30-day comment period which begins with notice of the availability of the EAW in the Minnesota Environmental Quality Board (EQB) Monitor. Comments on the EAW should address the accuracy and completeness of information, potential impacts that are reasonably expected to occur that warrant further investigation, and the need for an EIS. A copy of the EAW may be obtained from the MPCA by calling (651) An electronic version of the completed EAW is available at the MPCA Web site 1. Project Title: Commission Wastewater Treatment Facility 2. Proposer: Minnesota River Valley Public Utilities Commission 3. RGU: Minnesota Pollution Control Agency Contact Person Jon Peterson, P.E. Contact Person Dana Vanderbosch and Title Environmental Engineer and Title Project Manager Address 1960 Premier Drive Address 520 Lafayette Road North Mankato, Minnesota St. Paul, Minnesota Phone (507) Phone (651) Fax (507) Fax (651) Reason for EAW Preparation: EIS Scoping Mandatory EAW X Citizen Petition RGU Discretion Proposer Volunteered If EAW or EIS is mandatory give EQB rule category subpart number and name: Minn. R , subp. 18(B) 5. Project Location: County Le Sueur City Le Sueur 1/4 SW 1/4 Section 25 Township 112N Range 26W p-ear1-04 TDD (for hearing and speech impaired only): (651) Printed on recycled paper containing 30% fibers from paper recycled by consumers

3 Figures and Attachments for the EAW: Figure 1 Map showing the general project location in Le Sueur County, Minnesota; Figure 2 United States Geological Survey 7.5 minute, 1:24,000 scale map indicating project location; Figure 3 Process flow diagram; Figure 4 Site plan; Figure 5 Henderson lift station and force main alignment; Figure 6 National Wetland Inventory (NWI) map; and Figure 7 Site soils map. Attachment A Minnesota Department of Natural Resources (DNR) Natural Heritage and Nongame Research Program Response letter; and Attachment B Minnesota Historical Society s State Historic Preservation Office (SHPO) letter. 6. Description: a. Provide a project summary of 50 words or less to be published in the EQB Monitor. The Minnesota River Valley Public Utilities Commission (MRVPUC) is proposing a new mechanical activated sludge wastewater treatment facility (WWTF) with a treatment capacity of 1.84 million gallons per day (mgd) in the city of Le Sueur, Le Sueur County, Minnesota, to treat wastewater from the cities of LeSueur and Henderson. Treated effluent will be discharged to the Minnesota River. b. Give a complete description of the proposed project and related new construction. Attach additional sheets as necessary. Emphasize construction, operation methods and features that will cause physical manipulation of the environment or will produce wastes. Include modifications to existing equipment or industrial processes and significant demolition, removal or remodeling of existing structures. Indicate the timing and duration of construction activities. Background The city of Le Sueur currently operates a three-cell stabilization pond WWTF located in Henderson Township in Sibley County, which treats wastewater from the city of Le Sueur. The Le Sueur WWTF consists of one 2.12-acre aeration cell with clarifier (which only services flow from the Le Sueur Cheese Company), two 34-acre stabilization/basins and one 24.5-acre stabilization/basin, and has an average wet weather (AWW) design flow of.895 mgd. The controlled discharge to the Minnesota River (Class 2B, 3B, 4A, 4B, 5, 6) during spring and fall is authorized under National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) Permit No. MN This permit has been expired since The city of Henderson operates an activated sludge WWTF located in the city of Henderson in Sibley County. The Henderson WWTF consists of one lift station, a bar screen, a contact stabilization tank, a clarification tank, an aeration tank, a chlorination tank, a dechlorination tank, and an aerobic sludge digestion system, and has an AWW design flow of.181 mgd. The continuous discharge to an unnamed creek (Class 2B, 3B, 4A, 4B, 5, 6), which flows to the Minnesota River (Class 2B, 3B, 4A, 4B, 5, 6), is authorized under NPDES/SDS Permit No. MN This permit was most recently reissued on June 2, 2003, and modified on June 10, Proposed Project In March 2005, the cities of Henderson and Le Sueur formed the MRVPUC through implementation of a joint power agreement. The MRVPUC is proposing to construct a new mechanical activated sludge Commission Wastewater Treatment Facility 2 Environmental Assessment

4 WWTF with biological phosphorus removal, to be located across the Minnesota River from the existing Le Sueur WWTF ponds in the SW¼ of Section 25, T112N, R26W, city of Le Sueur, Le Sueur County (Figures 1 and 2). The proposed MRVPUC WWTF will combine the wastewater flows from the cities of Le Sueur and Henderson and discharge treated effluent to the Minnesota River. Once the proposed MRVPUC WWTF is operational, the existing Le Sueur and Henderson WWTFs will be decommissioned. The proposed WWTF will have an AWW design flow of 1.84 mgd. This proposed capacity will represent an expansion over the cities current combined treatment capacity, which is 1.08 mgd. In the year 2000, the estimated population of Le Sueur and Henderson combined was 4,832. Population projections indicate that the cities may reach a combined population of 6,380 by the year With the proposed capacity of 1.84 mgd, the MRVPUC WWTF will be able to accommodate future growth and development while maintaining a reliably high-quality effluent. The proposed project will include the addition of the following major structures and unit processes: Preliminary Treatment. A mechanically-operated screen will be used to trap sticks, rags, and debris that could interfere with other process units. Screenings will be automatically dewatered for disposal to the landfill. A manual screen will serve as back-up to the mechanical screen. Following screening, flow will pass through a mechanical grit removal process, which will remove sand, grit and other inorganic debris from the wastewater that reduce the volume of the extended aeration basins and cause premature wearing of pumps and equipment. The separated debris will be washed, dewatered and deposited in a dumpster for landfill disposal. The preliminary treatment system that only services flow from the Le Sueur Cheese Company will also continue to operate. Biological Treatment. The proposed project will add an extended aeration activated sludge process consisting of three concrete aeration basins, fine bubble diffusers, and centrifugal blowers. Biological phosphorous removal facilities will be incorporated as part of the aeration basins. The pretreated wastewater from the Le Sueur Cheese Company will enter the proposed WWTF at this point. Settling. The wastewater will flow from biological treatment into the three clarifiers, allowing the solids in the wastewater to be separated from the liquid. Some of the settled solids will be returned into the aeration basins for additional food for the micro-organisms, and the remaining biosolids go to the biosolids treatment process. Disinfection. The proposed WWTF would disinfect the effluent using either chlorine or ultraviolet (UV) light to reduce the possibility of pathogenic organisms in the discharge wastewater. If chlorine is used, the effluent would be dechlorinated using sodium bisulfite prior to discharge. Discharge. Treated effluent will be continuously discharged to the Minnesota River through approximately 280 feet of 18-inch outfall pipe. An outfall structure will be constructed on the bank of the river. Biosolids Processing. Wastewater biosolids consist of solids removed from raw wastewater and biological solids generated in the treatment process. Sludge generated in the treatment process will be stored and then dewatered prior to entering a heat pasteurization/biosolids drying process. The heat pasteurization process takes a dewatered sludge, heats and dries the dewatered sludge, and ultimately Commission Wastewater Treatment Facility 3 Environmental Assessment

5 produces Class A biosolids that are 90 percent solids. The biosolids will be stored in a building that provides 180 days of storage and eventually applied on MPCA-approved land application sites. Figures 3 and 4 provide more detail on the proposed WWTF. Henderson Lift Station/Sewer Force Main. A new lift station, an approximate five-mile (23,500 feet) long, eight-inch sewer force main and a 3,000 foot, 27-inch gravity pipeline will be constructed to convey raw wastewater from the city of Henderson to the proposed MRVPUC WWTF. The proposed pipeline alignment will cross the Minnesota River traveling east from the city of Henderson alongside Trunk Highway (TH) 19. The alignment will run south at County Road 34, southeast on Henderson Station Road, south alongside Highway 169 and south alongside Doppy Lane. The pipeline route will continue south alongside the Chicago and Northwestern Railroad to a lift station in Mayo Park in the city of Le Sueur. From there, the gravity line will travel across Mayo Park alongside TH 112, and then under the highway to the WWTF site (Figure 5). To minimize disturbance, the force main will be installed using trenchless methods (such as directional boring), though excavation will need to occur at all connections, air release manhole locations, boring pits and jacking pits. The gravity line pipe will be installed using open cut methods across a park, along a street ditch and through a wooded area. Trenches for gravity main construction will be 7 to 12 feet deep and feet wide. The portion of the line to travel under TH 112, Le Sueur Creek and the Chicago and Northwestern Railroad will be constructed using trenchless methods. For construction of both the force main and the gravity line, any excavated material will be stockpiled and replaced upon completion of construction. All drilling mud will be hauled and disposed of at an approved site. All disturbed areas will be returned to their original condition, whether it is bituminous, gravel, grass, woodland, or cropland. Construction of this project is expected to take approximately 21 months and to be completed by spring c. Explain the project purpose; if the project will be carried out by a governmental unit, explain the need for the project and identify its beneficiaries. The project will be carried out by the MRVPUC, which consists of the cities of LeSueur and Henderson. The project purpose is to provide a reliable means to treat wastewater within the cities through the year The beneficiaries of this project will be the current and future residents of the cities and the current and future commercial and industrial users located in within the cities. d. Are future stages of this development including development on any outlots planned or likely to happen? Yes No If yes, briefly describe future stages, relationship to present project, timeline and plans for environmental review. The WWTF is designed for a 20-year life and will handle a population of 6,380 people, plus additional commercial/industrial growth. The cities expect to reach this level of growth by If growth exceeds projections, improvements may be required before Environmental review for a future expansion, if required, would occur at some unknown point in the future. e. Is this project a subsequent stage of an earlier project? Yes No If yes, briefly describe the past development, timeline and any past environmental review. Commission Wastewater Treatment Facility 4 Environmental Assessment

6 The proposed MRVPUC WWTF will be a new facility. As such, the proposed project has not undergone previous environmental review; however, both cities have recently submitted proposals to expand their existing WWTFs. An EAW for a proposed expansion to the Le Sueur WWTF was placed on public notice on July 7, A separate EAW for a project proposal that would expand the facility that currently provides pretreatment of wastewater generated from the Le Sueur Cheese Company, enabling it to completely treat the Le Sueur Cheese Company s wastewater and discharge it, was also prepared and placed on public notice on July 7, The negative declaration on the need for an EIS for both projects was signed on September 10, Neither project has moved forward. The city of Henderson submitted a draft EAW to the MPCA on May 21, 2003, which described a project proposal to expand the existing Henderson WWTF. The city of Henderson later indicated they did not intend to proceed with the project, so the draft EAW was returned to them on January 27, Project Magnitude Data Total Project Area (acres) 40* or Length (miles) 5.0 Number of Residential Units: Unattached Attached maximum units per building Commercial/Industrial/Institutional Building Area (gross floor space): total square feet 12,750 Indicate area of specific uses (in square feet): Office 750 Manufacturing Retail Other Industrial Warehouse Institutional Light Industrial Agricultural Other Commercial (specify) 12,000 (WWTF) Building height If over 2 stories, compare to heights of nearby buildings * The site on which the proposed Facility will be situated is approximately 40 acres in size; however, only approximately 15.7 acres of this site will be disturbed for construction. Much of the remaining acreage is not suitable for development. 8. Permits and approvals required. List all known local, state and federal permits, approvals and financial assistance for the project. Include modifications of any existing permits, governmental review of plans, and all direct and indirect forms of public financial assistance including bond guarantees, Tax Increment Financing and infrastructure. Commission Wastewater Treatment Facility 5 Environmental Assessment

7 TABLE 8-1 LIST OF REQUIRED PERMITS AND APPROVALS Unit of Government Type of Application Status MPCA Preliminary Facility Plan Approval Completed MPCA Nondegradation-to-All-Waters Review Completed MPCA Plans and Specifications To be submitted MPCA NPDES/SDS Permit Submitted and under review MPCA NPDES/SDS Minnesota River Basin General Phosphorus Permit Phase I To be submitted MPCA NPDES General Stormwater Permit for Construction Activities To be submitted DNR Natural Heritage and Nongame Database Review Completed DNR Public Waters Work Permit To be submitted DNR Public Utility License To be submitted DNR Temporary Water Appropriation Permit To be submitted, if necessary SHPO Archeological and Historical Review Completed Minnesota Department of Utility Permit on Trunk Highway Right of To be submitted Transportation Way (Form 2525) LeSueur County Work in Right of Way Permit To be submitted City of Le Sueur Building Permit To be submitted Tyrone Township Work in Right of Way Approval Under review Chicago and Northwestern Railroad Railroad Crossing Permit To be submitted 9. Land use. Describe current and recent past land use and development on the site and on adjacent lands. Discuss project compatibility with adjacent and nearby land uses. Indicate whether any potential conflicts involve environmental matters. Identify any potential environmental hazards due to past site uses, such as soil contamination or abandoned storage tanks, or proximity to nearby hazardous liquid or gas pipelines. The site on which the WWTF will be situated is an area of the city of LeSueur that is zoned industrial and is comprised of several separate parcels, the past uses of which have included an old barn, a residential home, bulk oil storage, and fertilizer storage. The Minnesota River is immediately west of the site; the Chicago and Northwestern Railroad is immediately east of the site. TH 112 runs east of the railroad and Le Sueur, Incorporated (a foundry) is located across the highway from the proposed site. The existing LeSueur Cheese Company wastewater pretreatment facility will be immediately north of the proposed WWTF site. Undeveloped land will be located immediately to the south. A portion of the city of Le Sueur is within one mile of the site. Review of MPCA databases revealed one leaking underground petroleum storage tank (Leak ID 15010) in very close proximity to the proposed WWTF construction site. The site was discovered in There has been some contamination to ground water and monitoring is ongoing. Though construction will occur in close proximity to this leak site, it will not actually disturb contaminated soils. Commission Wastewater Treatment Facility 6 Environmental Assessment

8 The proposer is aware of the condition of this adjacent site and will be vigilant during construction. If contaminated soils are encountered during construction, they will be reported to the Minnesota State Duty Office. No other potential environmental hazards have been discovered on the proposed WWTF or pipeline construction sites. 10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after development: Before After Before After Types 1-8 wetlands Lawn/landscaping Wooded/forest Impervious Surfaces Brush/grassland Other (describe*) Cropland TOTAL *Open treatment tanks 11. Fish, Wildlife, and Ecologically Sensitive Resources. a. Identify fish and wildlife resources and habitats on or near the site and describe how they would be affected by the project. Describe any measures to be taken to minimize or avoid impacts. Wildlife in the vicinity of the proposed site primarily consists of species native to southern Minnesota. Species include deer, squirrels, rabbits, small mammals, snakes, turkeys, songbirds, amphibians, raptors, fish and waterfowl. The proposed construction site is land that is highly disturbed and does not provide quality wildlife habitat, though the Minnesota River is located immediately west of the site and the river does support fish and wildlife. A portion of the property on which the WWTF will be situated is below the 100- year flood elevation; however, all structures proposed for the WWTF (excepting the outfall structure) will be located above the 100-year flood elevation, as required by the MPCA. The slope between the WWTF and the river is now, and will remain, vegetated. The proposed pipeline will be laid in the rights of way of several different roads. The rights of way have been previously disturbed and are unlikely to provide quality habitat. Further, much of the force main will be bored rather than laid by trenching and so little disturbance of the right of way will be necessary. Where trenching or open disturbance of the right of way will be necessary, efforts will be made to restore the land to its pre-construction condition as much as possible. All drilling mud will be hauled and disposed of at an approved site. The NPDES/SDS Permit to be issued to the WWTF will contain and enforce effluent limits and operating conditions intended to protect fish and wildlife living in and utilizing the Minnesota River. An outfall structure will be constructed on the bank of the Minnesota River. This work will require an NPDES General Stormwater Permit for Construction Activity and a DNR Public Waters Work Permit. These permits are expected to mitigate potential effects of erosion and sedimentation from construction activities near the Minnesota River. Significant impacts to the wildlife from the proposed project are not anticipated. b. Are any state (endangered or threatened) species, rare plant communities or other sensitive ecological Commission Wastewater Treatment Facility 7 Environmental Assessment

9 resources such as native prairie habitat, colonial waterbird nesting colonies or regionally rare plant communities on or near the site? Yes No If yes, describe the resource and how it would be affected by the project. Indicate if a site survey of the resources has been conducted and describe the results. If the DNR Natural Heritage and Nongame Research program has been contacted give the correspondence reference number. ERDB Describe measures to minimize or avoid adverse impacts. The Minnesota Natural Heritage and Nongame database has been reviewed to determine if any rare plant or animal species or other significant natural features are known to occur within an approximate one-mile radius of the proposed sites to be disturbed. Based on this review, the DNR has identified that freshwater mussels in the Minnesota River and native plant communities, including red oak-sugar maple-basswood forest and pin oak-burr oak woodland, may be impacted by the proposed development. The proposer will be directional boring to lay pipe underneath the Minnesota River and does not anticipate disturbing the river bed where mussels might be found. The DNR s review of this proposal preparatory to issuing a Public Waters Work Permit is also anticipated to help identify needed mitigations. Further, much of the pipeline route will be directional bored and work will occur within existing cleared rights of way. Therefore, significant impacts to the species listed by the DNR are not anticipated. The letter is included as Attachment A. 12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration (dredging, filling, stream diversion, outfall structure, diking, and impoundment) of any surface waters such as a lake, pond, wetland, stream or drainage ditch? Yes No If yes, identify water resource affected. Describe alternatives considered and proposed mitigation measures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the water resources affected are on the PWI. A new outfall structure will be constructed on the bank of the Minnesota River. New discharge pipe (approximately 280 feet in length and 18 inches in diameter) will extend from the proposed WWTF through the 100-year floodway, as mapped by the Federal Emergency Management Agency. It is anticipated that the structure will consist of concrete wing walls to protect the pipe and a concrete splash pad below the pipe invert. A trash rack will be placed over the opening to prevent debris from entering the outfall pipe. Construction of the outfall structure will require a Public Waters Work Permit from the DNR. Construction of the city of Henderson force main will cross public watercourses at several points. They include: Minnesota River at U.S. Highway 19; Le Sueur Creek at TH 112; and An unnamed watercourse (a tributary to the Minnesota River) west of Highway 169 on Henderson Station Road. The alignment also crosses this unnamed public watercourse again in at least two places where it runs parallel to Henderson Station Road near Henderson Station. All pipeline construction activities potentially impacting these public watercourses will be conducted in accordance with a Public Utility License issued by the DNR. Additionally, all construction associated Commission Wastewater Treatment Facility 8 Environmental Assessment

10 with this proposed project will require an NPDES General Stormwater Permit for Construction Activities, which is expected to mitigate effects of erosion and sedimentation from construction activities to the receiving waters. The NWI does not show any wetlands on the proposed WWTF site or along the proposed pipeline alignment (Figure 6). 13. Water Use. Will the project involve installation or abandonment of any water wells, connection to or changes in any public water supply or appropriation of any ground or surface water (including dewatering)? Yes No If yes, as applicable, give location and purpose of any new wells; public supply affected, changes to be made, and water quantities to be used; the source, duration, quantity and purpose of any appropriations; and unique well numbers and DNR appropriation permit numbers, if known. Identify any existing and new wells on the site map. If there are no wells known on site, explain methodology used to determine. No dewatering is anticipated to be needed for construction of the proposed WWTF or for the city of Henderson force main; however, temporary dewatering may be needed for construction of the gravity line from the Mayo lift station to the WWTF. If dewatering at the site exceeds 10,000 gallons per day or 1,000,000 gallons per year, a temporary Water Appropriations Permit will be obtained from the DNR and the proposer will comply with all requirements of that permit. All dewatering water will be treated to remove sediment prior to discharge to the Minnesota River. The proposed WWTF will be connected to the public water supply; no new wells will be needed. 14. Water-related land use management districts. Does any part of the project involve a shoreland zoning district, a delineated 100-year flood plain, or a state or federally designated wild or scenic river land use district? Yes No If yes, identify the district and discuss project compatibility with district land use restrictions. The stretch of the Minnesota River that flows downstream from the proposed discharge location is not designated as wild or scenic. A portion of the property on which the WWTF will be situated will be below the 100-year flood elevation; however, all structures proposed for the WWTF (except the outfall structure) will be located above the 100-year flood elevation, as required by the MPCA. The city of Le Sueur has a Flood Plain Management Ordinance that was adopted in 1989 and updated in The project will comply with this ordinance. 15. Water Surface Use. Will the project change the number or type of watercraft on any water body? Yes No If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding or conflicts with other uses. 16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: 15.7 acres; 48,444 cubic yards. Describe any steep slopes or highly-erodible soils and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after project construction. Commission Wastewater Treatment Facility 9 Environmental Assessment

11 It is anticipated that the Henderson force main will be installed primarily using trenchless technology (i.e., boring), though excavation will need to occur at all connections, air release manhole locations, boring pits and jacking pits. The Mayo Park gravity pipeline will be installed using open cut methods across Mayo Park, along a street ditch and through a wooded area. Trenches for gravity main construction will be 7 to 12 feet deep and feet wide. The portion of the line to travel under TH 112, Le Sueur Creek and Chicago and Northwestern Railroad will be constructed using trenchless methods. The project proposer will be required to obtain an NPDES General Stormwater Permit for Construction Activities from the MPCA to control erosion and runoff during construction. This permit must be obtained prior to commencing any land-disturbing activities (i.e., clearing, grading, filling and excavating) at the site. The permit specifically requires implementation of Best Management Practices (BMPs). Construction plans will include BMPs, such as the following: scarifying only those portions of the site actively under construction; placing silt fencing and bale checks down slope of any land that is graded; grading that is part of the construction project will be no greater than a 3:1 slope; and seeding and re-vegetating disturbed areas as soon as possible. Minimizing disturbance and phasing of the proposed project, along with diligent temporary stabilization of all slopes and areas of exposed soil, will be necessary to prevent erosion and the discharge of sediment to state waters. All excavated material will be stockpiled and replaced upon completion of construction. All drilling mud will be hauled and disposed of at an approved site. All disturbed areas will be returned to their original condition whether it is bituminous, gravel, grass, woodland, or cropland. There are no steep slopes or highly erodible soils in WWTP the project area. Control measures, if needed, for the steep slopes that construction of the Henderson pipeline may encounter will be addressed by the NPDES General Stormwater Permit for Construction Activities. 17. Water Quality Surface-water Runoff. a. Compare the quantity and quality of site runoff before and after the project. Describe permanent controls to manage or treat runoff. Describe any storm-water pollution prevention plans. Management of stormwater generated at the project site is required. The NPDES General Stormwater Permit for Construction Activities will have specific requirements for the treatment and overall management of industrial stormwater prior to discharge from the site. The Permit will also require that a Stormwater Pollution Prevention Plan (SWPPP) be developed to manage pollutants in stormwater runoff from the site that will occur during construction and after construction is complete. The SWPPP is a detailed plan that will identify all sources of possible stormwater contamination for the project, provide an inventory of exposed significant materials, evaluate facility areas for exposure of significant materials to stormwater, describe structural and non-structural BMPs to be used to minimize contamination of stormwater, develop a preventive maintenance program, develop a spill prevention and response procedure, develop schedules for routine inspections of BMPs, and identify personnel responsible for implementing and managing the SWPPP. SWPPP and BMP implementation strategies must be prepared prior to submitting a permit application. Commission Wastewater Treatment Facility 10 Environmental Assessment

12 Typical erosion and sedimentation control measures, such as silt fences and bale checks, will be used during construction. The proposed WWTF will create approximately two acres of impervious surfaces. A vegetated buffer will separate the proposed WWTF and the Minnesota River, which will provide runoff an opportunity for infiltration before it leaves the site. The proposed project will create ~two acres of impervious surfaces. It is expected that very little fertilizer will be used on the grassy areas of the proposed WWTF. Since stormwater runoff will be controlled and treated during and after construction, it is expected that the change in quantity and quality of site runoff before and after the construction will be negligible. b. Identify routes and receiving water bodies for runoff from the site; include major downstream water bodies as well as the immediate receiving waters. Estimate impact runoff on the quality of receiving waters. Any runoff leaving the site will run to the Minnesota River and thence to the Mississippi River. As mentioned, a vegetated slope will separate the proposed WWTF and the Minnesota River, which will provide a modest opportunity for infiltration before it leaves the site. The quality of runoff produced by the proposed project is not expected to impact receiving waters. 18. Water Quality Wastewater. a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewater produced or treated at the site. The wastewater treated at the proposed WWTF will consist of typical domestic and industrial strength wastewater from the cities of Le Sueur and Henderson. The city of LeSueur has several industrial users of the existing LeSueur WWTF; however, the largest is the LeSueur Cheese Company, and wastewater from this company is pretreated before it is sent to the city of Le Sueur s WWTF. This will continue to be the practice in the future. Table 18-1 shows the composition and quantity of the municipal wastewater to be treated at the site. TABLE 18-1 DESIGN PARAMETERS OF PROPOSED WWTF MRVPUC WWTF AWW design flow (mgd) 1.84 Average dry weather flow (mgd) 1.26 Peak Hourly wet weather (mgd) 3.43 Peak Instantaneous Wet Weather (mgd) 4.15 BOD Annual average, pound per day (pounds/day) 1,953 TSS Annual average (pounds/day) 2,166 Total Kjeldahl nitrogen Annual average (pounds/day) 340 Total Phosphorus Annual average (pounds/day) 113 Commission Wastewater Treatment Facility 11 Environmental Assessment

13 b. Describe waste treatment methods or pollution prevention efforts and give estimates of composition after treatment. Identify receiving waters, including major downstream water bodies, and estimate the discharge impact on the quality of receiving waters. If the project involves on-site sewage systems, discuss the suitability of site conditions for such systems. The proposed MRVPUC WWTF will consist of pretreatment through screening and grit removal, activated sludge with biological phosphorus removal, primary clarifier and UV disinfection. Sludge will be dewatered and pasteurized to produce a Class A biosolids. Stabilized biosolids will be stored on site and later land applied to MPCA-approved agricultural land. Treated effluent will be discharged through a new outfall structure to the Minnesota River, a class 2B, 3B, 4A, 4B, 5, and 6 water of the state. The designated use shall permit the propagation of and maintenance of a healthy community of cool and warm water sport or commercial fish and associated aquatic life, and their habitats. The water shall be suitable for aquatic recreation of all kinds, including bathing, for which the water may be usable. The Minnesota River eventually flows to the Mississippi River. The MPCA will set effluent limits in the NPDES/SDS Permit intended to prevent the degradation of the receiving waters. The WWTF will be designed to meet the effluent limitations and any other requirements contained in the NPDES/SDS Permit. The proposed project meets the definition of a significantly expanded discharge under Minn. R , and this has triggered the need for a nondegradation review to all (non-outstanding resource value) waters of the state. The MPCA has completed this review and has proposed the following effluent limits for the proposed WWTF s discharge: TABLE 18-2 ANTICIPATED EFFLUENT LIMITS FOR PROPOSED WWTF 1 Effluent Parameter Limiting Concentration or Range 5-day Carbonaceous BOD April-November 25 milligrams per liter (mg/l) December-March 15 mg/l TSS 30 mg/l Fecal Coliform Group Organisms April-October 200 organisms/100 ml ph Dissolved Oxygen 6.0 mg/l Total Phosphorus 12-month average 1 mg/l May-September mass limit 2,923 pounds total for 5-month period 2 Annual mass limit 5,610 pounds total for 12-month period (which includes the May-September phosphorus mass allocation) Mercury Monitor quarterly Other Acute Whole Effluent Toxicity Testing Quarterly, to start on date of initial operation Commission Wastewater Treatment Facility 12 Environmental Assessment

14 1. Average monthly limits unless stated otherwise in parentheses. 2. The summer phosphorus limit ensures the discharge will comply with the Lower Minnesota River Dissolved Oxygen Total Maximum Daily Load (TMDL) study implementation schedule. See below for more information. Phosphorus: May September. The lower Minnesota River has been designated as impaired for low dissolved oxygen. In response to this impairment, the MPCA developed the Lower Minnesota River Dissolved Oxygen TMDL Study. Monitoring data indicate that during periods of the year when flows within the river are low, excess phosphorus loads from point and nonpoint sources encourage algal blooms. When the algae die, they decompose and this decomposition process utilizes dissolved oxygen in the river, creating a shortage of dissolved oxygen needed by aquatic organisms. The TMDL, which was submitted to the U.S. Environmental Protection Agency and approved in September 2004, identified significant reductions in phosphorus loads would be needed to reverse the dissolved oxygen impairment on the lower Minnesota River. WWTFs discharging to the Minnesota River Basin contribute approximately two-thirds of the total phosphorus load to the lower Minnesota River during low flow periods. The TMDL required phosphorus reductions from WWTFs discharging to the Minnesota River Basin. These reductions will be implemented in two phases over a ten-year period. Phase I will be implemented through the Minnesota River Basin General Phosphorus Permit (Basin Permit), which addresses the first five years of the ten-year implementation period. On December 1, 2005, the Basin Permit was issued. The goal of this Basin Permit is an aggregate 35 percent reduction (from baselines) in phosphorus discharged from WWTFs by the end of the Basin Permit term (November 30, 2010). Phase II will be implemented through another Basin Permit after expiration of the first Basin Permit. The Basin Permit contains mass phosphorus limits for WWTFs that discharge to the Minnesota River Basin. These mass phosphorus limits apply from May 1 to September 30 each year. The existing Le Sueur and Henderson WWTFs are covered by the Basin Permit and their allowable phosphorus loads are 2,602 and 321 pounds, respectively, for a combined total of 2,923 pounds for the two cities for the five-month period. The Basin Permit authorizes the discharge of phosphorus from new and expanding WWTFs to the Minnesota River Basin as long as the facility applies for coverage and operates in accordance with the provisions of the Basin Permit. Therefore, a proposed WWTF must obtain coverage under both an individual NPDES/SDS Permit and under the Basin Permit. The proposed WWTF discussed in this EAW will obtain coverage under the Basin Permit. The current allocations to the cities of Le Sueur and Henderson will be combined and appropriated to the proposed WWTF through the Basin Permit. In other words, there will be no increase in the allowable mass of phosphorus to be discharged from May to September over what is currently allowed. Phosphorus: General. Neither the existing Le Sueur nor Henderson WWTFs have an effluent phosphorus limit. The proposed WWTF will have a 1 mg/l effluent phosphorus limit and a 6.97 kilogram per day (approximately 5,610 pounds per day) mass phosphorus limit. As mentioned in the section above, no more than 2,923 pounds of this phosphorus will be discharged between May and September each year. Commission Wastewater Treatment Facility 13 Environmental Assessment

15 The effluent phosphorus concentration limit, along with the annual mass phosphorus limit, will result in a decrease in the amount of phosphorus currently discharged to the Minnesota River by the existing Le Sueur and Henderson WWTFs. The mass phosphorus limit from May to September to be contained in the Basin Permit will ensure compliance with the Lower Minnesota River Dissolved Oxygen TMDL. Mercury. The proposed WWTF will discharge to the Minnesota River near the Le Sueur Creek confluence. The segment of the river downstream from this point is designated as impaired for aquatic consumption due to mercury. Mercury is known to be present in municipal effluents and is primarily associated with TSS. An analysis of the project proposal indicates that TSS loads will not increase from those discharged currently. The MPCA staff anticipates the additional solids removal that will accompany compliance with the phosphorus limit will also aid the WWTF in assuring that TSS loads do not increase. Therefore, an increase in mercury from the proposed project is not anticipated. c. If wastes will be discharged into a publicly owned treatment facility, identify the facility, describe any pretreatment provisions and discuss the facility s ability to handle the volume and composition of wastes, identifying any improvements necessary. Not applicable. d. If the project requires disposal of liquid animal manure, describe disposal technique and location and discuss capacity to handle the volume and composition of manure. Identify any improvements necessary. Describe any required setbacks for land disposal systems. Not applicable. 19. Geologic hazards and soil conditions. a. Approximate depth (in feet) to Ground water: 8 minimum; 15 average. Bedrock: 40 minimum; >50 average. Describe any of the following geologic site hazards to ground water and also identify them on the site map: sinkholes, shallow limestone formations or karst conditions. Describe measures to avoid or minimize environmental problems due to any of these hazards. A full geotechnical study (soil borings and classification of the soil) of the site has been completed and no environmental concerns were identified. Eleven test borings, ranging in depth of 16 feet to 26 feet, were drilled and the borings indicated a general soil profile of surficial topsoil/fill overlying varying alluvial deposits with alluvial sand at depth. The test borings did not show any environmental contamination and indicated that the proposed structures can be supported on conventional spread footings. There are no known sinkholes, shallow limestone formations or karst conditions in the proposed construction areas. b. Describe the soils on the site, giving Soil Conservation Service (SCS) classifications, if known. Discuss soil granularity and potential for ground-water contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. According to the Natural Resources Conservation Service soil data bank, the soil on the site is listed as Sparta loamy fine sand, which is typically described as a gently sloping, well-draining soil (Figure 7). Commission Wastewater Treatment Facility 14 Environmental Assessment

16 The soils along the pipeline route are generally loams and clays, with moderate permeability characteristics. The following table summarizes the SCS soil classification information for these soils: TABLE 19-1 SOILS FOUND ALONG PIPELINE ALIGNMENT SCS Code Description Permeability 39 Wadena loam Moderate - Rapid 94 Terril loam Moderate 106 Lester loam Moderate 109 Cordova clay loam Moderate - Slow 114 Glencoe clay loam Moderate - Slow 239 LeSueur clay loam Moderate 317 Oshawa silt loam Moderate - Slow 329 Chaska loam Moderate - Rapid 414 Hamel clay loam Moderate - Slow 463 Minneiska fine Sandy loam Moderate - Rapid 945 Lester-Havick-Storden complex Moderate - Rapid 978 Cordova -Rolfe complex Moderate - Slow 1901 LeSueur-Lester complex Moderate Ground water contamination potential is low, as these soils tend to have significant water-holding capacity. Any potential contamination from spills will be handled according to accepted operating practice, with spilled material removed from site as repairs are made to the pipeline. Pipelines will be installed according to industry standards for water tightness. Lift stations will be monitored continually utilizing Supervisory Control and Data Acquisition systems for pump operations, with error messages indicating potential system failures. Any chemicals stored on site for use in the treatment process will be stored in the treatment facility in containers with secondary containment systems. Tanks and piping used for the containment and treatment of wastewater shall be leak tested by approved methods prior to being placed into operations. 20. Solid Wastes, Hazardous Wastes, Storage Tanks. a. Describe types, amounts and compositions of solid or hazardous wastes, including solid animal manure, sludge and ash, produced during construction and operation. Identify method and location of disposal. For projects generating municipal solid waste, indicate if there is a source separation plan; describe how the project will be modified for recycling. If hazardous waste is generated, indicate if there is a hazardous waste minimization plan and routine hazardous waste reduction assessments. Commission Wastewater Treatment Facility 15 Environmental Assessment

17 As part of the treatment process, the proposed WWTF will produce sludge. Sludge will be dewatered and pasteurized to produce a Class A biosolids. Stabilized biosolids will be stored on site for 180 days and then land applied to MPCA-approved agricultural land. This type of sludge treatment will be consistent with Minn. R It is anticipated that 2,000 pounds per day of dry solids will be generated at the proposed WWTF. Screenings and grit removed during the preliminary treatment processes will be transported to the nearest available landfill for disposal. The existing Le Sueur WWTF is a stabilization pond system that retains and stabilizes the wastewater sludge within the pond system. Once the ponds have been decommissioned, there will be some wastewater sludge in the bottom on the ponds that has not yet been stabilized. This sludge will be adequately treated in accordance with MPCA Minn. R b. Identify any toxic or hazardous materials to be used or present at the site and identify measures to be used to prevent them from contaminating ground water. If the use of toxic or hazardous materials will lead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize or eliminate the waste, discharge or emission. The following chemicals will be stored on site to aid in the treatment of the wastewater: Ferric chloride (as a back-up to biological phosphorus removal); Polymer (as a back-up to biological phosphorus removal); Sodium hydroxide (for odor scrubber); Sulfuric acid (for odor scrubber); Sodium hypochlorite (for odor scrubber); and Sodium bisulfite (for dechlorination if chlorine is used for disinfection) The tanks will be placed in a containment area to hold any spillage or overflow and prevent any discharge of the materials to the ground surface. The chemicals will be stored in above-ground tanks with secondary containment systems. Any leaks would be immediately noticed on the floor of the building. The tank would be repaired or replaced and would not be taken outside where ground contamination could occur. The proposed WWTF may also use chlorine gas for disinfection. If so, the chlorine gas system will be housed in a separate building with controlled access, and with all the leak detection and safety equipment that such a system requires. If any hazardous materials were found during construction, the material would be removed and disposed of according to the MPCA guidelines. The MPCA would be notified of any such findings as soon as possible. c. Indicate the number, location, size and use of any above or below ground tanks to store petroleum products or other materials, except water. Describe any emergency response containment plans. The proposed WWTF will have a 500-gallon diesel fuel storage tank for the purpose of supplying fuel to the emergency generator in times of power outages. The tank will be provided with a secondary containment tank and will have an alarm system to monitor the secondary containment tank in case of leaks. Commission Wastewater Treatment Facility 16 Environmental Assessment

18 21. Traffic. Parking spaces added: ~4 Existing spaces (if project involves expansion): Estimated total average daily traffic generated: Estimated maximum peak hour traffic generated (if known) and its timing: Provide an estimate of the impact on traffic congestion affected roads and describe any traffic improvements necessary. If the project is within the Twin Cities metropolitan area, discuss its impact on the regional transportation system. A few parking spaces will be added for wastewater operators. Only MRVPUC vehicles will be permitted on site. The proposed WWTF will not significantly increase traffic in the area once the WWTF is operational. 22. Vehicle-related Air Emissions. Estimate the effect of the project s traffic generation on air quality, including carbon monoxide levels. Discuss the effect of traffic improvements or other mitigation measures on air quality impacts. Note: If the project involves 500 or more parking spaces, consult EAW Guidelines about whether a detailed air quality analysis is needed. During construction, there will be some additional air emissions to the area from construction equipment, though there will be no significant increase in vehicle-related air emissions once the facility is operational. The only traffic to the site will continue to be the facility operators and other authorized personnel. 23. Stationary Source Air Emissions. Describe the type, sources, quantities and compositions of any emissions from stationary sources of air emissions such as boilers, exhaust stacks or fugitive dust sources. Include any hazardous air pollutants (consult EAW Guidelines for a listing), any greenhouse gases (such as carbon dioxide, methane, and nitrous oxides), and ozone-depleting chemicals (chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons or sulfur hexafluoride). Also describe any proposed pollution prevention techniques and proposed air pollution control devices. Describe the impacts on air quality. The WWTF will have a back-up 500-kilowatt diesel generator to be used in times of electrical power outages. Air emissions from the emergency power generator will be infrequent and minor in nature. The proposer has calculated the potential air emissions to be released by the natural gas-fired boiler that will provide the heat needed to pasteurize the biosolids and for the bagging operation, and has concluded that an Air Emission Permit will not be required for the proposed Facility. The potential air emissions are shown below in Table TABLE 23-1 POTENTIAL AIR EMISSIONS Particulate matter Nitrogen oxides Odors, noise and dust. Will the project generate odors, noise or dust during construction or during operation? Yes No If yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures to mitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts on them. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated by operations may be discussed at item 23 instead of here.) Odor. Odors can sometimes arise with the operation of wastewater treatment ponds; however, mechanical activated sludge treatment processes (such as the proposed WWTF) are aerated systems and normally do not cause odors. Since the proposed WWTF will be aerated and a three-stage chemical odor scrubber will Commission Wastewater Treatment Facility 17 Environmental Assessment

19 be installed to minimize any odors from the WWTF, conflicts between residents and the city of Le Sueur regarding operation of the proposed WWTF are not anticipated. Noise. There will be a temporary increase in noise generated by heavy machinery during the construction of the WWTF. The contractors will comply with city of Le Sueur noise ordinances. Construction would be limited to regular daily working hours. Operation of the proposed WWTF will not create noise disturbances. Dust. During construction, dust emissions will increase temporarily. The contractor will be required to employ appropriate measures to minimize the amount of dust produced during construction, such as watering the site, planting temporary grass cover, and the use of crushed rock in travel areas. Operation of the proposed WWTF will not create dust. 25. Nearby resources. Are any of the following resources on or in proximity to the site? a. Archaeological, historical, or architectural resources? Yes No b. Prime or unique farmlands or land within an agricultural preserve? Yes No c. Designated parks, recreation areas, or trails? Yes No d. Scenic views and vistas? Yes No e. Other unique resources? Yes No If yes, describe the resource and identify any project-related impacts on the resources. Describe any measures to minimize or avoid adverse impacts. Archaeological, historical, or architectural resources. A cultural resource review request was submitted to the SHPO. The SHPO has indicated there are no properties or known or suspected archeological sites where the WWTF will be situated; however, a number of architectural sites, including several churches and historic houses in the city of Henderson were identified. None of the historic sites are located directly in the proposed path of the pipeline. The review of the pipeline alignment also revealed several archeological sites near the Minnesota Valley Rest Area, the Henderson Mill, the Joseph R. Brown Steamboat Landing, and one unnamed site. Due to the proximity of the pipeline route to listed archaeological sites, the potential does exist that additional resources of cultural significance will be encountered during pipeline construction; however, the pipeline will be constructed within the previously disturbed right of way of various roads and the Chicago Northwestern Railroad, so the potential for encountering resources not already discovered is minimal. If, during the course of construction of the facility or installation of the pipeline, an area is discovered that has the potential to be significant historically or archaeologically, the MRVPUC will hire an archaeologist to determine site potential, and will work with the archaeologist and SHPO to determine appropriate mitigation measures to protect the area. A copy of the SHPO correspondence is included with this EAW as Attachment B. Prime or unique farmlands or lands within an agricultural preserve. The soil on which the proposed WWTF will be constructed is not prime farmland. The pipeline will be installed in road rights of way, areas previously disturbed and not suitable for agriculture. Designated parks, recreation areas, or trails. Mayo Park in the city of Le Sueur will be within a mile of the proposed WWTF site. Though there will be some disruption of park activities for a short period during construction of the Henderson pipeline, operation of the completed pipeline is not anticipated to conflict with recreation in the park. Commission Wastewater Treatment Facility 18 Environmental Assessment

20 Scenic views and vistas. Scenic views or vistas are not known to be present in the area. Other unique resources. The proposed WWTF will be located adjacent to the Minnesota River, which provides habitat for many fish and wildlife species. The various permits described in Item 8 of this EAW are intended to protect the natural resources within the area. Items 11 and 12 of this EAW also provide additional information on the potential for impacts to wildlife in the area. 26. Visual impacts. Will the project create adverse visual impacts during construction or operation? Such as glare from intense lights, lights visible in wilderness areas and large visible plumes from cooling towers or exhaust stacks? Yes No If yes, explain. 27. Compatibility with plans and land use regulations. Is the project subject to an adopted local comprehensive plan, land use plan or regulation, or other applicable land use, water, or resource management plan of a local, regional, state or federal agency? Yes No If yes, describe the plan, discuss its compatibility with the project and explain how any conflicts will be resolved. If no, explain. The project described in this EAW is being proposed to address the wastewater treatment needs for the cities of LeSueur and Henderson. Both cities have identified the need for this project and have incorporated it into their city plans. Potential stormwater issues for the proposed WWTF will be addressed per the city of Le Sueur Storm Water Management Ordinance. Additionally, any flood plain issues will be addressed per the city of Le Sueur Flood Plain Management Ordinance, which was adopted in 1989 and updated in There are local water planners in both Le Sueur and Sibley counties. These planners have been made aware of the project proposal, which appears to be consistent with local water plans and regulations. 28. Impact on infrastructure and public services. Will new or expanded utilities, roads, other infrastructure or public services be required to serve the project? Yes No If yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is a connected action with respect to the project must be assessed in the EAW; see EAW Guidelines for details.) Potable water supply, electrical service, and an access road already exist at the site. The electrical service may have to be upgraded to accommodate the increased process equipment at the site. Minor additions to the water utility and road system will be needed to serve this project. Commission Wastewater Treatment Facility 19 Environmental Assessment

21 29. Cumulative impacts. Minn. R , subp. 7, item B requires that the RGU consider the cumulative potential effects of related or anticipated future projects when determining the need for an EIS. Identify any past, present or reasonably foreseeable future projects that may interact with the project described in this EAW in such a way as to cause cumulative impacts. Describe the nature of the cumulative impacts and summarize any other available information relevant to determining whether there is potential for significant environmental effects due to cumulative impacts (or discuss each cumulative impact under appropriate item(s) elsewhere on this form). The availability of municipal utilities will allow additional development in the cities of Le Sueur and Henderson. Development will be encouraged in accordance with current zoning and land use requirements and will comply with applicable local ordinances and state codes and regulations intended to manage, minimize, or eliminate any adverse impacts. Increased development will also result in increased traffic, air pollution, stormwater runoff, and solid waste generation. As residential and commercial areas expand, the amount of farmland, open space and wildlife habitat in the area will decrease. The cities will need to regularly assess and address impacts that occur due to the secondary development. 30. Other Potential Environmental Impacts. If the project may cause any adverse environmental impacts not addressed by items 1 to 28, identify and discuss them here, along with any proposed mitigation. None. 31. Summary of issues. List any impacts and issues identified above that may require further investigation before the project is begun. Discuss any alternatives or mitigative measures that have been or may be considered for these impacts and issues, including those that have been or may be ordered as permit conditions. All anticipated impacts with the proposed project have been identified in responses to previous questions in this worksheet. Commission Wastewater Treatment Facility 20 Environmental Assessment

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23 Figure 1 Project Location Map Project Location

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25 Process Flow Diagram LeSueur Raw Wastewater Pumping Station Henderson Raw Wastewater Pumping Station Preliminary Treatment LeSueur Cheese Co. Pretreatment Facility Aeration Basins Clarifiers Disinfection Biosolids Treatment and Storage Surface Water Discharge Land Application Figure No. 3 Extended Aeration Activated Sludge Treatment Process Flow Diagram MRVPUC, Minnesota

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