If you have any questions on the EAW, please contact Lynne Kolze of my staff at (651)

Transcription

1 August 3, 2001 TO: RE: INTERESTED PARTIES City of Delavan Sewage Collection and Wastewater Enclosed is the (EAW) for the proposed City of Delavan Sewage Collection and Wastewater, Faribault County. The EAW was prepared by the Minnesota Pollution Control Agency (MPCA) and is being distributed for a 30-day review and comment period pursuant to the Environmental Quality Board (EQB) rules. The comment period will begin the day the EAW availability notice is published in the EQB Monitor, which will likely occur in the August 6, 2001, issue. Comments received on the EAW will be used by the MPCA in evaluating the potential for significant environmental effects from this project and deciding on the need for an Environmental Impact Statement (EIS). A final decision on the need for an EIS will be made by the MPCA Commissioner after the end of the comment period. If a request for an EIS is received during the comment period, or if the Commissioner recommends the preparation of an EIS, the nine-member MPCA Citizens Board (Board) will make the final decision. The final EIS need decision will also be made by the Board if so requested by the project proposer, other interested parties or MPCA staff and if this request is agreed to by one or more members of the Board or the MPCA Commissioner. The Board meets once a month, usually the fourth Tuesday of each month, at the MPCA office in St. Paul. Meetings are open to the public and interested persons may offer testimony on Board agenda items. A listing of Board members is available on request by calling (651) Please note that comment letters submitted to the MPCA do become public documents and will be part of the official public record for this project. If you have any questions on the EAW, please contact Lynne Kolze of my staff at (651) Sincerely, Beth G. Lockwood District Planning Supervisor Operations and Planning Section North, South, and Metro Districts BGL:sjs Enclosure

2 ENVIRONMENTAL ASSESSMENT WORKSHEET Note to reviewers: The (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: City of Delavan Sewage Collection and Wastewater 2. Proposer: City of Delavan 3. RGU: Minnesota Pollution Control Agency Contact Person Bruce Firkins Contact Person Lynne Kolze and Title Bolton & Menk, Inc. and Title Planner Principal Address 219 N. Main Address 520 Lafayette Road North Fairmont, 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 , Subpart 18B. 5. Project Location: County Faribault City/Twp City of Delavan/Delavan Township Collection System SW ¼ NE ¼ Section 36 Township T104N Range R27W SE ¼ NW ¼ Section 36 Township T104N Range R27W NE ¼ SW ¼ Section 36 Township T104N Range R27W NW ¼ SE ¼ Section 36 Township T104N Range R27W Pond System SW ¼ NE ¼ Section 35 Township T104N Range R27W TDD (for hearing and speech impaired only): (651) Printed on recycled paper containing 100% fibers from paper recycled by consumers

3 Tables, Figures, and Appendices attached to the EAW: 1. State of Minnesota map showing the project location; 2. United States Geological Survey 7.5 minute, 1:24,000 scale map indicating project boundaries; 3. Wastewater Treatment Facility (WWTF) Schematic; 4. City of Delavan Map showing proposed Sanitary Sewer System; 5. Land use map; 6. ½ mile radius Leaking Underground Storage Tanks map; 7. Minnesota Department of Natural Resources (DNR) Natural Heritage Database letter; 8. Soils map; and 9. Minnesota Historical Society (MHS) letter 6. Description: a. Provide a project summary of 50 words or less to be published in the EQB Monitor. The city of Delavan is proposing to construct a new sanitary sewage collection and stabilization pond wastewater treatment system. The new sewage system would serve the entire community of Delavan. The pond system would treat an Average Wet Weather (AWW) flow of 54,000 gallons per day (gpd) and discharge to Judicial Ditch #1 in Faribault County. 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 Delavan does not currently hold a National Permit Discharge Elimination System (NPDES) permit for its wastewater treatment system. The wastewater treatment system for the city of Delavan, originally constructed in the 1930's, consists of a partial gravity collection system and an Imhoff tank. The Imhoff tank is essentially a settling tank that provides very little waste treatment. Wastewater leaving the Imhoff tank flows through a combined storm and sanitary sewer and is discharged into a nearby ditch. Approximately 45 buildings in Delavan are not served by any sanitary sewer, though they do have substandard septic tanks. Most of these tanks discharge effluent directly to tile lines or a storm sewer, rather than a drain field, which is required by law. The Proposed Project The city of Delavan proposes to construct new sanitary sewer and wastewater treatment systems that would serve the entire community. The new sewage system would be constructed separate from the storm water collection system. Sewage would be delivered via forcemain to 3 new 2.5-acre stabilization ponds, which would be constructed 1/2 mile west of town. Wastewater would be pumped directly to the primary treatment ponds, where natural physical and chemical processes would break down wastes. These processes would be performed by naturally occurring bacteria, microorganisms, plants, and algae. The ponds are designed to be shallow (a maximum of 6 feet in depth) to allow sunlight to penetrate to the bottom and to maintain aeration and mixing (Figure 3). Shallow depths prevent anaerobic, or septic conditions, and the odors associated with 2

4 them. Sunlight would provide a natural disinfection process through ultraviolet radiation, destroying many pathogens present in the wastewater. During the biological treatment process, some biosolids settle to the pond bottom, where they continue to undergo treatment. These biosolids typically form a thin sludge blanket on the bottom of the ponds. In most facilities, the amount of biosolids settling on the pond bottom averages less than two feet. The ponds are designed to provide 180-days of wastewater storage, and to provide adequate time for waste treatment. Approximately every 180 days, wastewater would be discharged from the ponds to Judicial Ditch No. 1, and ultimately, Rice Creek. The treated wastewater would be discharged in a way that would be coordinated with periods of mid- to high-river flows in the spring and fall, when the receiving stream is the least sensitive. Both the sanitary sewer and storm sewer work would take place within the existing city limits, on formerly developed residential or commercial property or within the city of Delavan s right-of-way (Figure 4). Construction of the sanitary sewer forcemain and the outfall piping leading from the ponds to Judicial Ditch #1, would take place on existing farmland, requiring a 40-foot temporary construction easement. Once construction is completed, these areas would be available for farming purposes again. Both of these pipes would run along the north side of the existing railroad right-of-way from the west edge of town, out to the site of the pond system. In addition, there would be a short section of outfall piping that would cut across existing farmland away from the railroad right-of-way in a northeasterly direction to the judicial ditch. Construction of the ponds would result in the loss of approximately 19.2 acres of prime farmland. In addition, a portion of a 2.3-acre area would be needed for construction of an access road from County State Aid Highway 15 to the facility. Part of this access road would actually be constructed over an existing field road so the full 2.3 acres of farmland would not be altered. Construction of the stabilization ponds would begin in the spring of 2002 and be completed in the summer of 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 city of Delavan s Imhoff Tank treatment system was constructed in the 1930 s and is no longer an acceptable method of wastewater treatment in Minnesota. Septic systems used by some city residents discharge directly to tile lines and do not meet current state rules or county codes governing on-site systems. Because portions of the existing system operate as a combined sewer or have crossconnections with storm drainage lines, numerous residences are subject to the backup of sewage into their basements. Sewage back-ups could present a significant health and safety threat to a number of residents. Separation of the domestic sewage and stormwater systems would significantly reduce the potential for sewage back-ups. 3

5 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. Delavan 's population of 240 people is expected to remain steady or decline slightly over the next 20 years. For purposes of this proposal, the facility capacity was designed to treat waste from 240 people through the year 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. The city of Delavan's wastewater treatment system has never been upgraded. 7. Project Magnitude Data Total Project Area (acres) 19.2 (pond site) or Length (miles) 3 (collection system) Number of Residential Units: Unattached 0 Attached 140 maximum units per building n/a Commercial/Industrial/Institutional Building Area (gross floor space): total square feet n/a Indicate area of specific uses (in square feet): Office n/a Manufacturing n/a Retail n/a Other Industrial n/a Warehouse n/a Institutional n/a Light Industrial n/a Agricultural n/a Other Commercial (specify) n/a Building height n/a If over 2 stories, compare to heights of nearby buildings n/a 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. Unit of Government Type of Application Status MPCA Facility Plan Approval Approved MPCA NPDES Permit Submitted MPCA NPDES General Storm Water Permit To be submitted MPCA Plans and specifications approval To be submitted City of Delavan Plans and specifications approval To be submitted US Department of Agriculture (USDA)-RWS Plans and specifications approval Wastewater Grant Program preliminary engineering report To be submitted Approved 4

6 Unit of Government Type of Application Status Faribault County Conditional Use Permit To be submitted USDA -Rural Development Funding To be submitted Minnesota Department of Transportation Long Form Permit for Work in a Right-of-Way 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. Stabilization Ponds The stabilization pond system would be constructed on a 19.2-acre site 1/2 mile west of the city of Delavan (Figure 5). Land use in the vicinity of the proposed pond site is predominantly row crop agriculture. The land has never been used for industrial purposes. Stabilization pond systems do not typically create conflicts with agricultural land uses, especially since there are no building sites within a ¼ mile radius of the site. The pond could pose a potential for the generation of minor odors for brief periods in the fall and spring of each year, occurring when the ponds mix due to changes in temperature and wind. Those individuals most likely to experience odors are owners and residents of two farmsites that are located 1/3 and 1/2-mile north and northeast of the ponds. Setbacks from those residences conform to the MPCA recommended guidelines for siting stabilization ponds. Sewage Collection System The sewage collection system would be located within the city of Delavan, which is a small, rural residential community with few industries. The collection system would be located primarily within residential areas of the city. The in-town sewer work for this project would have only temporary impacts to residents during the replacement of existing below-grade sewers and street or grass surfaces. There are no known cultural or historical resources located in Delavan that could be impacted by sewer construction. The MPCA's Master Entity System (MES) was queried as to any records of previous or existing contamination in the vicinity of the stabilization ponds and sewage collection system. The MES is a comprehensive database that includes the Metropolitan Area Disposal Site Inventory, the outstate Dump Inventory, the Voluntary Investigation and Cleanup Inventory, as well as the files of the MPCA s remediation programs. The MES located three sites within a 1/4-mile radius of the proposed collection system in the city of Delavan, where leaking underground fuel tanks have previously been found. The sites were located at the Delavan School, Delavan Bus Garage, and Watanwon Farm Services (Figure 6). All of these sites have been addressed through state remediation programs. The leaking tanks were removed and disposed of according to state regulations and the sites are considered closed. Some contaminated soils still remain at the sites, however, contamination is very limited and is at a level not believed to pose a risk to residents of Delavan. 5

7 The construction of the sewage collection system should not involve disturbance of these sites. However, if the city of Delavan encounters contaminated soils, it will need to obtain a Utility Order which requires the proper removal and disposal of any contaminated soils encountered. Construction of the sewage system would cause only a temporary inconvenience for residents. Land uses would not permanently change as a result of the new collection system. 10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after development: Stabilization ponds Before After Before After Types 1-8 wetlands 7 7 Lawn/landscaping 0 0 Wooded/forest 0 0 Impervious Surfaces 0 0 Brush/grassland 0 0 Other (describe) 0 Cropland 21 6 Pond system with grassed dikes. 15 TOTAL 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. Stabilization Ponds Two small, unclassified wetlands, together, less than 5 acres in size, are located near the pond site. The National Wetlands Inventory lists the wetland to the south of the proposed ponds as semipermanently flooded. The wetlands would be purchased by the city of Delavan as part of the pond site, and would be protected from any potential drainage or farming activities. These wetlands would not be disturbed during or after construction of the ponds. There is also a small unclassified wetland near the northwest corner of the property. A small road would be constructed through this wetland. Total area impacted by the road would be 0.2 acres. This area has previously been used as a driveway by the current property owner. Any impacts to this wetland would be mitigated through the use of the county wetland bank. There are minimal wildlife resources around the proposed pond site. The wetlands on site provide some shelter for a number of wildlife species. The wildlife in the area may benefit from the pond system, since the ponds would provide additional open grass areas currently not available. The ponds would also provide habitat for various waterfowl and shorebirds since they hold water yearround. Sewage Collection System Only wildlife species accustomed to living in close proximity to humans would be found within the city limits. No threatened, endangered or special concern species are known to exist within the city of Delavan or within the vicinity of the proposed WWTF. Consequently, construction of the new sewage collection system and WWTF are not expected to impact wildlife in a significant way. 6

8 b. Are any state (endangered or threatened) species, rare plant communities or other sensitive ecological 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 Database has been reviewed to determine if any rare plant or animal species are known to occur within an approximate one-mile radius of the proposed facility. Based on this review, the DNR has stated that there are no known occurrences of rare species or natural communities in the area (Figure 7). 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. The pond system's outfall structure would be constructed near the bank of Judicial Ditch No. 1. The disturbed area around the outfall structure would be riprapped to reduce erosion and stabilize the bank. Construction would be performed during periods of low flow and would occur above the water level. Water flow in the ditch would not be affected. 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. Significant dewatering should not be necessary for construction of either the ponds or the sewage collection system. If conditions are not as expected, a water appropriations permit would be obtained from the DNR for dewatering activities. 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. 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. 7

9 16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: 19 acres; 48,000 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. Stabilization Ponds Due to the fact that construction of the proposed WWTF would disturb more than 5 acres of land, the city of Delavan must apply for a MPCA NPDES General Stormwater Permit. Erosion and sedimentation Best Management Practices (BMPs) would be used at the site, including silt fencing, bale checks, and grading to prevent significant runoff. The ponds' dike slopes would be mulched and seeded upon completion to stabilize the soil. Any runoff and sedimentation caused by excavation of soil would be contained on site and not allowed to flow to nearby surface waters. Sewage Collection System Standard BMPs would be used to reduce erosion during construction of the sewage collection system. 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. Stabilization Ponds Runoff from the pond site would flow generally northwest to Judicial Ditch No. 1, which eventually discharges into Rice Creek approximately 2 miles to the northwest. Runoff is the primary source of water in the judicial ditch and Rice Creek. When construction of the ponds is completed, the total quantity of runoff leaving the site would likely decrease, as the ponds would capture and retain all precipitation falling on them. As a result, water quality may improve to some degree since the ponds are replacing land that was used for row crop agriculture; a land use which may have contributed fertilizers and pesticides to surface waters in the past. A portion of the runoff around the pond site would be contained in the existing wetlands. Sewage Collection System Runoff quantity would not change due to the construction of the proposed collection system. Ground cover and slope would remain unchanged after the project is completed. 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. The quality of the runoff being discharged from the storm sewers and drain tiles would be improved, as all existing cross connections with the sanitary sewer would be removed. 8

10 Since runoff quality may improve as a result of this project, there should be a positive, though not significant impact on the 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. Wastewater would be generated by the residents of Delavan. No industrial wastewaters would be produced or treated at the site. Average Dry Weather and AWW flows would be 27,600 gpd and 54,000 gpd, respectively. Wastewater would consist of normal domestic sewage with the following loading characteristics: Biochemical Oxygen Demand (CBOD5) = 53 pounds (lbs)/day Total Suspended Solids (TSS) = 60 lbs/day 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. At the present time, residents and businesses in the city of Delavan send a significant amount of untreated or partially-treated wastewater to Judicial Ditch #1 and other nearby receiving streams via the stormwater sewer and tile lines. Wastewater treatment would be provided by stabilization ponds. Stabilization ponds provide an environment which is conducive to the growth and reproduction of bacteria, algae, and other more complex life forms. Organic matter in the wastewater are digested, metabolized, and stabilized through biological processes involving these organisms. Treated wastewater would be discharged to Judicial Ditch No. 1 which discharges to Rice Creek. Judicial Ditch No. 1 is assigned designated use classifications of 7, 3C, 4A, 4B, 5, and 6. Rice Creek is assigned designated use classifications of 2B, 3B, 4A, 4B, 5, and 6 waters of the state under MPCA rules. These use classifications include aquatic life and recreation, industrial consumption, agriculture and wildlife, aesthetic enjoyment and navigation, and other uses. When this project is completed, the proposed system would replace an unpermitted and insufficient treatment system with one that would meet effluent limits established by the MPCA to protect receiving waters. Downstream waters, including Rice Creek, the Maple River, and the Minnesota River could benefit to some degree from a reduction in nutrients, solids, and bacteria entering the watershed. The proposed pond system would be required to meet the following effluent limits: Substance or Characteristics Limiting Concentration or Range CBOD 5 25 milligrams per liter (mg/l) TSS 45 mg/l Fecal Coliform Organisms* 200 organisms/100ml ph (standard unit) *Applicable from May 1 through October 31 9

11 In addition, the city of Delavan would be required to monitor for phosphorus over the life of the permit (5 years). If after two years of monitoring, phosphorus levels in the effluent exceed an annual average of 4 mg/l, the city of Delavan would have to develop a Phosphorus Management Plan (PMP). If phosphorus levels are below 4mg/L (annual average), no PMP would be required. 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. n/a 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. n/a 19. Geologic hazards and soil conditions. a. Approximate depth (in feet) to Ground water: 2 minimum; 6 average. Bedrock: >20 minimum; n/a 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. No site hazards are known or expected around either the stabilization pond or sewage collection system. Soils in the area have low infiltration rates, reducing the potential for contamination. b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity and potential for groundwater contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. Stabilization Ponds Soils found at the pond site are Clarion loam and Marna silty-clay loam (Figure 8). These clay loams, found to depths greater than five feet, would be suitable for use in the construction of pond liners since they have a low permeability. The clay liners are designed to prevent the loss of wastewater due to seepage. Some leakage does occur from these ponds. The MPCA's pond construction criteria require that no more than 500 gallons per acre per day are lost through soil seepage. The MPCA has determined that this level of seepage should produce minimal to no impacts to groundwater. The water table varies depending on the topography. The ponds are being located where minimum groundwater depth is typically 6 feet or greater. Sewage Collection System Soils in the city of Delavan are typically clay loams. 10

12 The soils in both areas have a very high clay content, with little granular material. Permeability and infiltration rates are quite low, limiting groundwater contamination potential from any surface spills, or leakage. 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. Solids (sludge) from the wastewater would settle to the bottom of the ponds where it would continue to undergo biological stabilization and decomposition. Biosolids would not be removed from the ponds. Consequently, biosolids disposal would not be necessary. 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 groundwater. 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. n/a 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. n/a 21. Traffic. Parking spaces added: 0 Existing spaces (if project involves expansion): n/a Estimated total average daily traffic generated: n/a Estimated maximum peak hour traffic generated (if known) and its timing: n/a 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. 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. n/a 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. n/a 11

13 24. 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.) Dust may be generated during construction of both the ponds and sewage collection system, depending upon weather conditions. Water trucks would be used to control the dust when it begins to become airborne. Noise would also be generated by the construction equipment. The equipment would be operated during daylight hours. Noise would occur over a relatively short duration at any given site within Delavan. However, noise would be of longer duration at the pond site. Given that there are no residences within 1/4 mile of the ponds, there should be minimal impacts. Once the ponds are operating, odors may be generated for a few days during the spring and fall when the water in the ponds mixes after thawing and prior to freezing. Due to the setbacks from residences (1/4 mile, and from Delavan 1/2 mile), these odors should not create significant problems for nearby residents. 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. The MHS has been contacted regarding the possible presence of historic properties on the site of the proposed WWTF. Based on the MHS' review, no historic properties eligible for or listed on the National Register of Historic Places would be affected by this project (Figure 9). A total of 20 acres of farmland would be permanently removed from production. However, this is a small percentage of the 402,900 acres of prime farmland in the county. This project would not result in or encourage further loss of farmland resulting from an increase in development around the city of Delavan. 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. 12

14 The proposed project is located within the Minnesota River drainage basin. In recent years, there has been a concerted effort at the state and local levels to address both point and nonpoint sources of pollution in the river. An important part of that effort involves upgrading and improving existing wastewater treatment facilities within the river basin. This project should contribute to the overall goal of reducing pollution by 40 percent. 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.) A new sewage collection system would be constructed in conjunction with the wastewater ponds. This system would eliminate many noncompliant connections between homes, the existing storm sewer and drain tiles. 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 environmental impact statement. 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). No related or future projects are anticipated. The city of Delavan is not a growing community now, nor is it expected to be in the future. 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. All anticipated environmental impacts have been discussed. No adverse impacts are expected. 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. When the city of Delavan considered options for replacing the municipal wastewater collection and treatment system, they reviewed the following alternative treatment systems through the Facility Planning process: Mechanical Treatment Plant; Regionalization; Constructed Wetland; Septic Tank & Drainfield System; and Stabilization Ponds. Due to the comparatively small amount of wastewater that would be generated, the high cost of constructing and operating a mechanical treatment system, complexity of operation and maintenance, and staffing requirements, the mechanical treatment system alternative was not considered the most viable alternative. 13

15 The City of Delavan investigated Regionalization with its closest neighbors to the east and the west. During the negotiations, the city of Easton (six miles to the east) decided not to participate in the project. In addition, regionalization with the city of Winnebago (eight miles to the west) was found to be more expensive than other alternatives and was not chosen for that reason. A review of USDA Soil Conservation Service maps indicates that most soils in the Delavan area have poor permeability and high groundwater levels. Typical drain fields would not work in these soils. Mound systems, which are typically used in poor soils, have size limitations and would not work for a system the size of Delavan s. A Septic Tank and Drainfield System was not chosen for Delavan for these reasons. Constructed Wetlands require less land area than stabilization ponds and have less operation and maintenance costs than a package plant, but can involve high costs related to the chemical removal of phosphorous and land application of phosphorous sludge. In addition, constructed wetlands typically have a design life of only 15 years. As a result of these issues, this alternative was not chosen for the city of Delavan. Stabilization Ponds are commonly used in small communities for wastewater treatment. Although construction of stabilization ponds requires considerable acreage, ponds provide efficient, very low cost wastewater treatment when properly designed, constructed, operated, and maintained. Consequently, the city selected this alternative due to its cost effectiveness. 14

16 RGU CERTIFICATION. I hereby certify that: The information contained in this document is accurate and complete to the best of my knowledge. The City of Delavan Sewage Collection and Wastewater EAW describes the complete project; there are no other projects, stages or components other than those described in this document, which are related to the project as connected actions or phased actions, as defined at Minn. R , subps. 9b and 60, respectively. Copies of this EAW are being sent to the entire EQB distribution list. Name and Title of Signer: Beth G. Lockwood, District Planning Supervisor Operations and Planning Section; North, South, and Metro Districts Date: The format of the was prepared by the staff of the Environmental Quality Board at Minnesota Planning. For additional information, worksheets or for EAW Guidelines, contact: Environmental Quality Board, 658 Cedar St., St. Paul, MN 55155, , or at their Web site 15