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ENVIRONMENTAL ASSESSMENT WORKSHEET Note to reviewers: The Environmental Assessment Worksheet (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 651-297-8510. An electronic version of the completed EAW is available at the MPCA Web site http://www.pca.state.mn.us/news/eaw/index.html#open-eaw. 1. Project Title: Willmar Wastewater Treatment Facility and Conveyance System 2. Proposer: City of Willmar 3. RGU: Minnesota Pollution Control Agency Contact Person Melvin Odens, P.E. Contact Person Dana Vanderbosch and Title Director of Public Works and Title Project Manager Address 333 Southwest 6th Street Address 520 Lafayette Road North Willmar, Minnesota 56201 St. Paul, Minnesota 55155-4194 Phone 320-235-4913 Phone 651-297-1796 Fax 320-235-4917 Fax 651-297-2343 4. 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. 4410.4300, subp. 18 5.

Project Location:

County

Kandiyohi

City/Twp

City of Willmar, Willmar Township, St. Johns Township

1/2 1/4 Section Multiple, listed below Township 119N Range 35W and 36W

Existing Wastewater Treatment Facility (WWTF) City of Willmar: NW¼ of Section 23 of Township 119 North, Range 35 West Proposed WWTF

St. Johns Township: SE¼ of Section 23 of Township 119 North, Range 36 West

Willmar WWTF and Conveyance System Environmental Assessment Willmar, Minnesota 2 Worksheet

Pump Station at Benson Avenue City of Willmar: NW¼ of Section15 of Township 119 North, Range 35 West Pump Station at Willmar Avenue City of Willmar: NW¼ of Section 21 of Township 119 North, Range 35 West Forcemains

Willmar Township: W½ of Section 15; S½ of Section 16; SW¼ of Section19; SE, SW and NE¼ Sections of Section 20; NW¼ of Section 21; NW¼ of Section 29; and N½ of Section 30. All portions are within Township 119 North, Range 35 West.

St. Johns Township: SE¼ of Section 23 and S½ of Section 24 of Township 119 North, Range 36 West

Interceptor Sewer Willmar Township: SW¼ of Section 19; SE¼ of Section 20; N½ of Section 30; N½ of Section 29; SW¼ of Section 21; N½ of Section 28; N½ of Section 27; S½ of Section 22; and W½ of Section 23. All portions are within Township 119 North, Range 35 West. St. Johns Township: SE¼ of Section 23 and S½ of Section 24 of Township 119 North, Range 36 West Outfall Sewer St. Johns Township: SE¼ of Section 23, S½ of Section 24, and NW¼ of Section 25 of Township 119 North, Range 36 West Figures and Attachments for the EAW: Figure 1 Map showing the general project location in Kandiyohi County, Minnesota; Figure 2 U.S. Geological Survey 7.5 minute, 1:24,000 scale map indicating project location ; Figure 3 Proposed future planning and service areas; Figure 4 Proposed WWTF site plan; Figure 5 Aerial photograph – proposed WWTF location; Figure 6 Aerial photograph – conveyance corridor; Figure 7 Existing WWTF decommissioning plan; Figure 8 Tank site location map; Figure 9 Wetland impact summary; Figure 10a Map showing wetland delineations on proposed WWTF site; Figure 10b Map showing wetland delineations on west portion of conveyance route; Figure 10c Map showing wetland delineations on east portion of conveyance route; Figure 11a Well located on proposed WWTF site; and Figure 11b Wells located near conveyance corridor. Attachment A Minnesota Department of Natural Resources (DNR) Natural Heritage and Nongame Research Program letter dated October 19, 2006; Attachment B U.S. Fish and Wildlife Service (USFWS) Telephone Memorandum dated November 27,

2006; Attachment C Minnesota Historical Society’s State Historic Preservation Office (SHPO) letter dated

November 8, 2006; Attachment D Management Summary from the Report on Phase I Cultural Resources Assessment for the

proposed project; and Attachment E Letter dated October 2, 2007 from I&S Engineers & Architects, Inc. to Chippewa County.


6. Description:

a. Provide a project summary of 50 words or less to be published in the EQB Monitor. The city of Willmar (City) proposes to upgrade and relocate its existing 5.04 million gallons per day (mgd) wastewater treatment facility (WWTF) by constructing an expanded 7.51 mgd WWTF approximately 5.8 miles west of the existing WWTF in St. Johns Township in Kandiyohi County, Minnesota. The project also includes a new sanitary sewer interceptor, forcemain, and two pump stations, outfall sewer and modifications to the existing WWTF (Project). The existing WWTF will be decommissioned once the relocated facility is operational. In addition to the EAW, the draft National Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) Permit will be available for public comment concurrently. The contact person for the NPDES/SDS Permit is Lisa McCormick, at 320-231-5343.

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. I. Proposed Project

a) Proposed WWTF The proposed WWTF will be located on a 170-acre parcel that was acquired by the City in the

early 1990’s for the purpose of relocating the City’s existing WWTF. This site is currently used by the City for a compost site, a trap shooting range, and a biosolids transfer and storage facility (Figures 1, 2, and 5). In addition, a small portion of the site has been converted to a wetland mitigation area to compensate for wetland impacts associated with the Willmar Municipal Airport. The remaining areas are used for cropland. The proposed WWTF will be located next to the biosolids transfer and storage facility.

The proposed WWTF will treat all wastewater generated within the City’s sewer service area

(Figure 3). Municipal wastewater and production-related wastewater from the Jennie-O Turkey Stores (JOTS) will be treated in separate treatment processes at the proposed WWTF. The proposed WWTF is shown in Figures 5 and 6 and will include the following mechanical features (Figure 4):

• Preliminary treatment – designed to remove grit, debris, and odor; • Flow splitting structure – designed to equally distribute flow to downstream processes; • JOTS and municipal selectors – designed to enhance treatment performance; • JOTS and municipal oxidation ditches – designed to provide biological treatment of 5-day

Biochemical Oxygen Demand (CBOD), ammonia, and Total Suspended Solids (TSS); • JOTS and municipal chemical feed systems – designed to remove phosphorous; • JOTS and municipal secondary settling – designed to settle activated sludge; • Disinfection and aeration – designed to disinfect and re-aerate effluent prior to discharge to

ensure the effluent Dissolved Oxygen (DO) limit is achieved; • Liquid solids thickening and storage – designed to provide adequate cold-weather biosolids

storage;


• Biosolids transfer and storage facility (existing) – designed to store biosolids and pump to land application vehicles; and

• Administration building – designed to house employees, laboratory, and facility controls needed to operate the WWTF.

b) Conveyance System The proposed Project will involve construction of approximately 17,000 lineal feet (LF) of

48-inch diameter and 12,865 LF of 54-inch diameter gravity interceptor sewer to convey municipal wastewater from the existing WWTF to the proposed WWTF (Figures 2 and 6). The interceptor sewer will be located along a new 5.7-mile utility corridor within an urban and agricultural setting. The interceptor sewer from 1st Street to the proposed WWTF site follows portions of the 28th Avenue Southeast and 30th Avenue Southeast right-of-way. The remainder of the interceptor sewer crosses agricultural land. The interceptor sewer crosses Hawk Creek and two agricultural drainage ditches, the Burlington Northern Sante Fe (BNSF) railroad, and the Magellan natural gas pipe line.

For part of the route, the interceptor sewer will be co-located with the forcemain and outfall

sewer within the same utility corridor. A portion of the interceptor sewer along the 5th Street right-of-way between 19th Avenue Southeast and 28th Avenue Southeast was constructed in 2006 and 2007 to accommodate road reconstruction of 5th Street (Phase I - Waterview Business Park Interceptor Sewer). A portion of the interceptor sewer between 19th Avenue Southeast and the existing WWTF is planned for construction in late 2007, again to accommodate road construction of 5th Street (Phase II - Willmar Southern Interceptor Sewer). Installing the interceptor at the same time as the city street work avoided the substantial costs and public disruption of excavating the city streets twice. Item 6e of this EAW describes environmental review that has already been completed for Phases I and II.

Two pump stations and a forcemain (9,250 LF of 8-inch diameter and 20,575 LF of 14-inch

diameter) are needed to convey production-related wastewater from the two JOTS production facilities to the proposed WWTF (Figures 2 and 6). The forcemain between the two JOTS facilities will follow existing road and railroad rights-of-way. The forcemain between the Willmar Avenue JOTS and the proposed WWTF will be adjacent to the BNSF railroad right-of-way, in agricultural land to County Trunk Highway 5, where it continues in the interceptor sewer corridor the remainder of the way to the proposed WWTF. The forcemain will cross the Magellan pipe line and the BNSF railroad. A portion of the forcemain will be co-located with the interceptor sewer and outfall sewer within the same utility corridor. The remainder of the forcemain will be located along a 3.3-mile utility corridor within an urban and agricultural setting. The pump stations will be located in an urban setting along the forcemain corridor.

c) Outfall Sewer The outfall sewer (4,050 LF of 54-inch diameter pipe) will be needed to convey treated effluent

to Hawk Creek (Figure 2). It will be co-located within the same utility corridor as the interceptor sewer and forcemain.

d) Existing WWTF Once wastewater is routed to the proposed WWTF, the existing WWTF will be

decommissioned as a treatment facility. The existing administration building will be improved to better serve as a maintenance facility and collection system control center (Figure 7). Several of the process buildings will be converted to heated storage space.


The general Project location can be found on Figure 1. More detailed figures showing various Project components can be found on Figures 2-6.

II. Construction Methods

a) Proposed WWTP Construction of the WWTF will require mass grading of approximately 18 acres and a NPDES

General Stormwater Permit for Construction Activities. Topsoil will be removed and stored in a temporary stockpile for use in final site grading and landscaping. Site grading will be balanced to the extent possible. During construction, contractors will be required to minimize wetland impacts to the extent practicable and avoid all but one existing wetland.

Construction will involve excavation for buildings, structures and piping, storage of excavated

material, backfilling, compacting, paving, building construction, and formwork and placing of concrete for structures. Standard construction equipment and machinery such as trucks, backhoes, bulldozers, bobcats, cranes, loaders, graders, compactors, compressors, and dewatering pumps will be used.

b) Conveyance System The proposed Project will require approximately 10.1 miles of pipe installation within a

construction corridor ranging from approximately 50 feet wide (forcemain only) to approximately 200 feet wide (co-located interceptor sewer, forcemain, and outfall sewer). Construction methods include open cut utility trench excavation, boring or microtunneling and jacking pipe, manhole installation, backfilling, and site restoration. The forcemain piping will consist of pressure-rated polyvinyl chloride installed at depths varying between 7 to 20 feet deep. The gravity interceptor piping will consist of reinforced concrete pipe installed at depths varying between 20 to 45 feet deep.

Most of the pipe will be installed by open trench construction methods with trench support

structures (trench boxes) required. For excavations deeper than approximately 25 feet, a “bench” will be cut as a working platform for the equipment and for stockpiling materials. Pipe installation will include removing and segregating topsoil from other excavated materials for use in topdressing disturbed areas. In agricultural areas, topsoil will be restored after the trench backfill is compacted, and special care will be taken to limit compaction of the newly placed topsoil. All disturbed areas will be graded to match existing contours. Once the pipe has been installed, the land could be used for agricultural production once again. Unpaved, non-agricultural areas will be restored by seeding with a cover crop and perennial grass mix. Soil material will be excavated and backfilled using standard construction machinery including backhoes, bulldozers, loaders, trucks, and skid steers. Other expected construction equipment may include cranes, compressors, and dewatering pumps.

At railroad crossings and areas with extensive utility conflicts, pipe will be installed by

microtunneling or boring and jacking. All sediments generated by the pipe installation process will be dewatered on site. Water generated will be treated to reduce suspended solids prior to discharge. Dewatered sediments will be hauled off site in compliance with local and state regulations.


Following installation of the sewer, and prior to use, the entire length of the interceptor and forcemain will be leak tested and televised internally. Items 16 and 17 of this EAW provide more information on planned mitigations to manage stormwater runoff from this proposed Project.

c) Outfall Sewer Construction methods for the outfall sewer include open cut utility trench excavation, manhole

installation, endwall construction, backfilling, placement of geotextile fabric and riprap, and restoration. The outfall sewer depth ranges from approximately 12 feet to approximately 22 feet. The pipe will discharge into Hawk Creek at an elevation slightly above the normal water surface at an angle toward the flow direction of Hawk Creek. Riprap and geotextile fabric will be placed as permanent erosion control measures at the end of the outfall discharge and along the ditch banks to the top of the headwall structure. At the completion of construction of the outfall structure, all disturbed areas above the waterline not designated to have riprap will be restored with topsoil, seeding, and erosion control mat.

d) Existing WWTP The existing administration building will be improved to better serve as a maintenance facility

and collection system control center. Several of the process buildings will be converted to heated storage space. Process-related tankage will either be cleaned and abandoned or removed. Recyclable materials will be segregated as practicable during decommissioning. Following demolition, disturbed areas will be graded to match existing site grades and revegetated.

III. Proposed Implementation Schedule

The proposed implementation schedule for this Project is outlined below. This is a tentative schedule subject to change, though it should be noted that MPCA requires that the City’s WWTF be in compliance with an effluent phosphorous limit by the end of November 2010 (see Item 18 of this EAW for details).

TABLE 6-1

Proposed Implementation Schedule Item Proposed Date Final Facilities Plan May 2006 Design May 2006 – December 2007 EAW submittal September 2007 NPDES/SDS Permit submittal August 2007 – December 2007 Bidding January – March 2008 Construction May 2008 – August 2010 Start-up August 2010 Compliance with effluent phosphorus limit November 2010 Existing WWTP conversion June 2011

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 proposer is the City. The Project has several purposes. As of 2005, the City had an estimated population of 18,488. The proposed WWTF will be designed to accommodate anticipated growth within the City’s sanitary sewer service area to serve an estimated population in 2030 of 27,236.


In addition, the proposed WWTP is needed to achieve compliance with more stringent effluent discharge limits (see Item 18 for more information) and meet additional wastewater capacity requirements within the City. Lastly, the existing WWTF has experienced past complaints of objectionable wastewater odors. The proposed WWTF design will rectify objectionable wastewater odors by treating municipal wastewater separate from the JOTS food processing wastewater.

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.

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 project that is the subject of this EAW is the third phase of a comprehensive plan to relocate the existing WWTF, to install a new interceptor sewer between the existing and proposed WWTF, and to construct a new forcemain and pump stations to convey wastewater from two JOTS production facilities to the proposed WWTF. Phase I and Phase II (Figure 2) consist of short segments of the interceptor and were assessed through environmental review previously. The EAW for the Waterview Business Park Interceptor Sewer (Phase I) was prepared and a negative declaration on the need for an Environmental Impact Statement (EIS) was signed on September 27, 2006. Phase I was constructed in 2006 and 2007. An EAW for the Willmar Southern Interceptor Sewer (Phase II) was prepared and a negative declaration on the need for an EIS was signed on June 22, 2007. Phase II is planned to be constructed in October and November 2007. Phase I and Phase II were assessed through environmental review before Phase III (the subject of this EAW) to accommodate road construction of 5th Street. Installing the interceptor at the same time as the city street work avoided the substantial costs and public disruption of excavating the city streets twice.

7. Project Magnitude Data

Total Project Area (acres)

170 Acres (Total Site)

or Length (miles)

5.7-mile interceptor sewer 5.9-mile forcemain 0.8-mile outfall sewer

Number of Residential Units:

Unattached

NA

Attached

NA

Maximum units per building

NA

Commercial/Industrial/Institutional Building Area (gross floor space): total square feet

32,700


Indicate area of specific uses (in square feet): Office 6,000 Manufacturing NA Retail NA Other Industrial NA Warehouse NA Institutional NA Light Industrial NA Agricultural NA Other Commercial (specify) 26,700 Building height 10 – 40 If over 2 stories, compare to heights of nearby buildings NA

Note: The floor space in the preceding paragraph is for the proposed WWTF site. The office space is part of the administration building. The other industrial room space is for process and electrical space and garage space.

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.

TABLE 8-1

LIST OF REQUIRED PERMITS AND APPROVALS Unit of Government Type of Application Status MPCA

Facilities Plan for Wastewater Collection and Treatment Facilities

Approved

MPCA EAW – Waterview Business Park Interceptor Sewer (Phase 1)

Negative declaration signed September 27, 2006

MPCA EAW – Southern Interceptor (Phase 2) Negative declaration signed June 22, 2007

MPCA EAW – Willmar WWTF and Conveyance System Submitted September 2007

MPCA NPDES/SDS Permit Submitted October 2007

MPCA NPDES/SDS Minnesota River Basin General Phosphorus Permit – Phase I To be submitted

MPCA Plans and Specifications Approval To be submitted MPCA Sanitary Sewer Extension Permit To be submitted

MPCA NPDES General Stormwater Permit for Construction Activities To be submitted

DNR Natural Heritage and Nongame Database Review Response October 19, 2006

DNR Temporary Water Appropriation Permit (for construction)

To be applied for, if necessary

SHPO Archeological and Historical Review Complete November 8, 2006 Public Facilities Authority State Revolving Fund Application To be submitted Minnesota Department of Transportation (MNDOT)

Utility Permit on Trunk Highway Right-of-Way (Form 2525) To be submitted


TABLE 8-1 LIST OF REQUIRED PERMITS AND APPROVALS

Unit of Government Type of Application Status Kandiyohi County Ditch Crossing Authorization Submitted Kandiyohi County Approval for Utility Crossing To be submitted City of Willmar Building Permit To be submitted City of Willmar Grading and Erosion Control Plan To be submitted U.S. Army Corps of Engineers (USACE) Section 404 Permit Application To be submitted

Kandiyohi County Wetland Mitigation Approval To be submitted

MPCA Section 401 Water Quality Certification of USACE Section 404 Permit To be submitted

USFWS Federal Fish and Wildlife Database Review Response November 27, 2006Magellan Pipe Line Easement Encroachment Agreement To be submitted BNSF Pipeline 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. Adjacent Land Uses In general, the Project exists in an urbanized and rural agricultural setting. The proposed WWTF will be located in an agricultural setting approximately three miles west of the City limits, on an approximate 170-acre parcel that is occupied, in part, by the existing City-owned biosolids transfer and storage facility. The biosolids transfer and storage facility was constructed on approximately 6.5 acres of this parcel in 1996. The parcel is also used for a trap shooting range (approximately 41 acres), City-owned wetland mitigation site and other wetlands (approximately 10 acres), and City-owned yard waste composting (approximately 22 acres). The remainder of the parcel is cropland or uncultivated grassland. Figure 5 presents an aerial photograph showing the proposed WWTF parcel. The land uses adjacent to the proposed WWTF parcel are primarily agricultural lands used for commodity crop production, undeveloped land, scattered wetlands, and agricultural drainage ditches. Hawk Creek is located approximately one-quarter mile east of the proposed WWTF. The proposed forcemain and interceptor sewers will originate in urban areas and will cross through areas predominantly within an agricultural setting (Figure 6). The outfall sewer is in the same utility corridor as the interceptor and forcemain, across agricultural land, from the WWTF to Hawk Creek outfall. Environmental Hazards Evaluation There are no known potential environmental hazards associated with the west portion of the Project including the proposed WWTF site, the outfall sewer, or any adjacent lands. Several sites with known or potential sources of soil and ground-water contamination exist along the east portion of the sewer corridor. The MPCA database of leaking underground storage tanks (LUST) sites indicates test LUST sites exist adjacent to the interceptor and forcemain corridors (Figure 8). Based on information provided in the MPCA database, five of these sites pose a low environmental risk to this Project; however, five of these sites pose a medium environmental risk due to potential to encounter soil or ground-water contamination within or adjacent to these sites. The construction contractor will be


informed about the potential to encounter contamination and mitigative measures will be included in the construction contract to specify special handling and disposal requirements, if encountered. According to MPCA contaminated property records (“What’s in My Neighborhood” database search), there are four environmental sites near the Project area. The former Willmar City Dump, located near the existing WWTF, is undergoing a voluntary investigation and clean-up. The Willmar Brush Disposal Facility/Dump, located east of the interceptor sewer, is considered an unpermitted dump. These sites are located approximately ½-mile from the interceptor sewer corridor. There is a drainage ditch that separates these sites from the interceptor sewer and likely intercepts ground water. Therefore, it is not anticipated that the fill material associated with these sites extends into the Project area. If buried debris, impacted soil, or impacted ground water is encountered during Project construction, the material should be segregated, characterized, and handled in accordance with MPCA guidelines. The MPCA contaminated property database also identifies the Willmar Gas Manufacturing Site, located southeast of the proposed forcemain corridor, and the MNDOT 23 Yard Site, located north of the proposed interceptor sewer route. Both of these sites are undergoing a voluntary investigation and cleanup. Since both of these sites are being cleaned up, it is anticipated that no adverse environmental affects will be expected from these two sites. According to MPCA Voluntary Investigation and Cleanup staff, these sites have either been closed or have undergone sufficient remedial activities to reduce environmental impacts below current regulatory standards.

10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after

development: Proposed WWTF

Before After Before After Types 1-8 wetlands 1.6 1.6 Lawn/landscaping 0.5 8.5 Wooded/forest 0 0 Impervious Surfaces 1.5 4.5 Brush/grassland 6.6 2.4 Other (Open Tanks) 0 1.5 Cropland 8.3 0 TOTAL 18.5 18.5

Use of the City-owned land not dedicated to facilities associated with the proposed WWTF should not change. Impervious surfaces on this parcel will increase resulting from conversion of cropland to pavement and structures.

Existing WWTF

Before After Before After Types 1-8 wetlands 0 0 Lawn/landscaping 5.64 7.33 Wooded/forest 0 0 Impervious Surfaces 3.84 2.15 Brush/grassland 0 0 Other (Describe) 0 0 Cropland 0 0 TOTAL 9.48 9.48

The above information has been prepared assuming full decommissioning of the existing WWTF has been accomplished. This may be done in phases, depending on the costs involved. Impervious surfaces on this parcel will decrease resulting from conversion of pavement and structures to lawn.


Conveyance System Before After Before After Types 1-8 wetlands 6 6 Lawn/landscaping 8 8 Wooded/forest 2 2 Impervious Surfaces 6 6 Brush/grassland 1 1 Other (Describe) 0 0 Cropland 80 80 TOTAL 103 103

The estimated area needed for construction of the forcemains, interceptor sewer, and the outfall sewer assumes a range from 50 feet wide (forcemains) to 200 feet wide (co-located interceptor, forcemain, outfall sewers). The total area for these utility corridors is approximately 103 acres.

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.

Terrestrial Resources and Habitats The proposed WWTF and utility corridors are located in a predominantly agricultural setting. Terrestrial wildlife in the vicinity of the proposed construction sites consist primarily of species native to southern Minnesota. Potential species include deer, small mammals, turkeys, songbirds, raptors, and waterfowl. Because the majority of the proposed affected areas has been previously disturbed and is currently in agricultural crops, roadways, or mowed turf, the proposed Project is not expected to have a significant short- or long-term impact on local terrestrial wildlife. 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. Any wildlife displaced during construction or after construction would likely relocate to suitable nearby areas. Following construction, the proposed WWTF parcel will be converted from agricultural land use to grassland. These fallow natural areas will provide habitat for wildlife species common to central Minnesota. Aquatic Resources and Habitats Fish surveys completed by the DNR in the late 1970s and early 1990s indicate 28 species characteristic of a warm water fishery were observed in Hawk Creek, including, carp, green sunfish, spotfin shiners, sand shiners, flathead minnows, and white suckers. Game species, including, walleye, yellow perch, and channel catfish were also observed in low numbers. At times of the year, the flows in the reach where the proposed WWTF will discharge are less than one cubic foot per second. Though this reach likely does not support year-round the fish species listed previously, they may be present when flows are higher. The NPDES/SDS Permit to be issued to the proposed WWTF will contain and enforce effluent limits, monitoring and testing, and operating conditions intended to protect fish and wildlife living in and utilizing the Hawk Creek. An outfall structure will be constructed on the bank of Hawk Creek. Riprap and geotextile fabric will be placed as permanent erosion control measures at the end of the outfall discharge and along the ditch banks to the top of the headwall structure. At the completion of construction of the outfall structure, all disturbed areas above the waterline not designated to have riprap will be restored with topsoil, seeding and erosion control mat. These measures are expected to mitigate potential effects of erosion and sedimentation from construction activities near Hawk Creek. 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 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 20070306

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. Five known occurrences of rare species were identified; however, based on the nature and location of the proposed Project, the DNR does not believe the Project will affect any known occurrences of these rare species (Attachment A). The USFWS was contacted regarding the potential presence of federal-listed threatened or endangered species, as well as other rare or sensitive biological resources in the vicinity of the proposed Project. According to the USFWS database records, there are no known occurrences of rare species or habitats associated with this Project (Attachment B).

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. Wetland Assessment Overview One wetland assessment was completed by Pinnacle Engineering on the proposed WWTF parcel and a portion of the interceptor and forcemain corridor. The remainder of the interceptor and forcemain corridor interceptor and forcemain corridor was assessed by Barr Engineering. These two assessments identified approximately 42 potential wetlands within the general Project area (Figure 9); none are listed on the DNR Protected Waters Inventory. The Kandiyohi County Environmental Service Office reviewed the wetland assessments, field-checked the delineation of the accessible wetlands, and concurred with the assessments and delineations. Fifteen of the wetlands will be temporarily disturbed by pipeline crossings for the Project. One wetland at the new WWTF site will be permanently impacted (Figures 10a, 10b, and 10c). Permanent Wetlands Impacts Construction of the proposed WWTF is anticipated to directly impact 1.4 acres of wetland. Several alternate site layouts were considered, all of which had greater direct wetland impacts. The proposed layout was selected because it minimized wetland impacts. Wetland replacement for permanent, unavoidable wetland impacts resulting from the construction of the proposed WWTF is planned to be completed through the construction of a wetland on-site. A new wetland area and a protective upland buffer next to the wetland are planned to be constructed adjacent to an existing wetland located east of the parcel of land on which the proposed WWTF will be constructed in Section 23, Township 119 North, Range 36 West. Sufficient new wetland and upland buffer will be constructed to comply with the mitigation requirements set forth by the Wetland Conservation Act and Section 404 of the Clean Water


Act (2: 1 replacement). The wetland mitigation area will be constructed concurrent with the construction of the treatment facility, and protected with appropriate deed restrictions. Temporary Wetlands Impacts The Project will also require a temporary crossing of an estimated 6 acres of wetlands to construct the sewer. Avoiding wetlands to the extent practical was a major consideration in establishing the sewer and forcemain route. The wetlands will be restored to match pre-construction grades and revegetated following construction of the sewer. To minimize wetland impacts, construction Best Management Practices (BMPs) will be implemented in accordance with the Project-specific erosion control plan. The erosion control plan will provide specific BMP measures as well as construction phasing, vehicle tracking, and installation/inspection schedule. Wetland crossings will be constructed with open cut trench excavation techniques. Silt fencing will be used to prevent sediments from entering ditches or wetlands. Phased construction will be used to minimize the amount area disturbed at any one time and restoration will be completed within 14 days of the completion of construction in the immediate area. Erosion control mat will be installed on the restored ditch banks. Stream Crossing The Project includes a temporary crossing of Hawk Creek (County Ditch 10) to accommodate construction of the interceptor sewer and forcemain. The reach of Hawk Creek into which treated effluent will be discharged is not listed as a DNR-protected water, though reaches downstream are listed on the Protected Waters Inventory. Care will be taken to minimize impacts at the Hawk Creek crossing location. Stream crossings will be constructed with open cut trench excavation, boring or microtunneling methods. The NPDES General Stormwater Permit for Construction Activities will contain erosion control provisions that will ensure protection of the water quality of Hawk Creek regardless of which construction method is chosen. Cofferdams may be used as barriers in the ditch to allow construction of the pipeline. If used, the dams will be placed and constructed so as to cause minimum disruption to the aquatic environment. Fabric will be used to keep sediment from entering the waterway. Any dewatering discharge will be directed to filtered sump pits or sediment traps before entering the waterway. The contractor will be given the option of using trenchless construction methods, such as microtunnel or bore and jack, for the ditch crossings. Outfall Construction An outfall structure will be constructed on the bank of Hawk Creek. The outfall structure is not expected to alter the course or channel cross-section and the ditch bank will be stabilized with riprap. Original grade contours will be restored after construction and pre-construction drainage patterns will not be altered by the Project.

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. The Project will not require installation or abandonment of water supply wells. The proposed WWTF site has an existing water supply well (Well ID No.583054) that will supply potable water for the proposed WWTF.


The Minnesota County Well Index indicates there are 11 water supply wells located within approximately 300 feet of the proposed interceptor sewer or forcemain. Several of the wells are listed as “test wells” and are likely not in service. The City provided utility mapping showing the location of municipal wells, including three municipal wells near the proposed forcemain. The wells within 300 feet of the pipeline are listed below in Table 13-1 and are shown on Figures 11a and 11b.

TABLE 13-1 WATER SUPPLY WELLS WITHIN 300 FEET OF PROPOSED

INTERCEPTOR SEWER OR FORCEMAIN Well No. Location Distance from

pipeline Depth (feet)

Installed (year)

Comments

583054 T119N R36W, Section 23

At proposed WWTF site

101 1997 Well serves existing Biosolids storage facility

740734 T119N R35W, Section 29

200 feet south of interceptor sewer

Not Listed

Not Listed

Parcel ID #33-029-0050 3060 30th Street SW Willmar, MN 46201

210733 T119N R35W, Section 28

150 feet south of interceptor sewer

69 1970 Parcel ID #33-026-0020 3120 15th Street SW Willmar, MN 56201

210721 T119N R35W, Section 22

250 feet north of interceptor sewer

59 1965 Parcel ID #33-022-0050 PO Box 427 Willmar, MN 56201

102027 T119N R35W, Section 16

75 feet southeast of forcemain

340 Not Listed

Willmar Test Well, Bedrock 335 feet

102026 (No. 12)

T119N R35W, Section 16


340 Not Listed

Willmar Municipal Well 12, Bedrock 335 feet

212913 T119N R35W, Section 16,

75 feet east of forcemain

300 1964 Willmar Test Well #1, Bedrock 215 feet Not shown as an active well by Willmar Water Utility.

180331 T119N R35W, Section 16


340 Not Listed

Willmar Test Well

212914 T119N R35W, Section 16


201 1964 Willmar Test Well #2, Bedrock 354 feet (near Well 8)

236119 T119N R35W, Section 16

400 feet south of forcemain

416 1965 Willmar D4 Well, Bedrock 258 feet

180303 T119N R35W, Section 16

300 feet south of forcemain

303 Willmar Well , (Now W-15)

No. 7 T119N R35W, Section 16

110 feet north of forcemain

Willmar Municipal Well 7

No. 8 T119N R35W, Section 16


Willmar Municipal Well 8


Minn. R. 4725.4450 requires that the interceptor sewer be located more than 50 feet from any water supply well. The interceptor location for the proposed Project is compliant with this regulation. According to information provided by Willmar Water Utility, there are three municipal wells near the proposed forcemain: Well No. 7 (110 feet away), Well No. 8 (105 feet away) and Well No. 12 (75 feet away). Because of the distance to the interceptor and forcemain routes, dewatering activities during construction will not likely impact water supply wells along the sewer corridor. Dewatering Installation of the interceptor sewer, the forcemain, pump stations, and outfall sewer will likely require temporary dewatering during construction. This may involve the installation of temporary dewatering wells, well points, or dewatering sumps along the utility trench. Dewatering may also be required at the WWTF site for installation of some of the structures and piping. This may require the installation of temporary dewatering wells, well points and/or dewatering sumps. All dewatering activities are anticipated to be limited to the scope and duration of the specific construction activity. 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. Ground water from dewatering will be directed to a temporary settling basin or similar device to remove suspended solids below regulatory limits prior to discharge to the ground surface or a receiving waterway.

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 Project does not exist within a designated wild or scenic river land use district. Portions of the proposed underground sewer piping may be located in the 100-year floodplain; however, since the pipe will be underground, it will not alter the storage capacity within the floodplain. A review of available Federal Emergency Management Area information suggests that the 100-year flood plain has not been delineated in the vicinity of the proposed WWTF. Barr Engineering estimated the Hawk Creek 100-year flood plain elevation at approximately 1,108 mean sea level (±5.0 feet), near the proposed WWTF. The proposed WWTF will be constructed at an elevation that it would remain fully operational during a 25-year flood event and be protected from flooding during a 100-ear flood event.

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 acreage to be graded or excavated and cubic yards of soil to be moved: 18.5 at proposed WWTF

103 along pipelines acres;

62,000 (proposed WWTF) and 790,000 (pipe trenches)

cubic yards.

Describe any steep slopes or highly erodible soil and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after Project

construction. Except for ditch banks, there are no steep slopes (greater than 12 percent) located within the Project area, and only limited areas of highly erodible soils at the WWTF site, interceptor sewer, forcemain, and outfall sewer corridors. Regardless of the soil erosion potential, erosion control measures will be implemented throughout the Project area in accordance with a Project-specific erosion control plan. Since construction of the Project facilities will disturb more than one acre of land, a permit application for coverage under the NPDES General Stormwater Permit for Construction Activities will be obtained prior to construction. The permit application certifies that temporary and permanent erosion and sediment control plans have been prepared and implemented to prevent soil particles from being transported off site. Project-specific erosion control measures and BMPs will be specified in the permit and on construction plans. Measures may include the following: • scarifying only those portions of the site actively under construction; • installing silt fence down slope of graded areas; • using straw bale checks; • installing sediment filters and traps for dewatering; • installing erosion control matting or mulching; • constructing crushed rock tracking pads at designated construction access points. Soils tracked from

the construction site by motor vehicles and construction equipment will be cleaned from paved roadway surfaces throughout the duration of the construction project; and

• Seeding and revegetating disturbed areas immediately following construction.

BMPs will be implemented and maintained throughout the duration of the construction project to minimize adverse impacts from runoff. This will include defining work zones, and installing and maintaining silt fence or other appropriate stormwater control devices along the margins of the work zones. Construction entrances will be provided with stone tracking pads. Construction of the WWTP will also require construction, operation, and maintenance of a stormwater management area. The silt fencing or other erosion control measures will be inspected and maintained until disturbed areas have been revegetated to reduce the risk of erosion and sedimentation to adjacent wetlands or waterways. Specific measures will be detailed in the erosion control plan required as part of the permit. All disturbed areas along the interceptor sewer, forcemain, and outfall corridors will be restored to pre-construction contours. Erosion control measures will be implemented prior to construction and will remain in place until site stabilization has been achieved. Regular inspection will ensure that measures implemented remain effective.


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. The City will obtain an NPDES General Stormwater Permit for Construction Activities from the MPCA for this Project. This permit has specific requirements for the treatment and overall management of stormwater prior to discharge from the site. The permit also requires preparation of a Stormwater Pollution Prevention Plan (SWPPP) to manage pollutants in stormwater runoff from the site that will occur during pre- and post-construction. Due to the increase in impervious surfaces (i.e., roads and structures), the quantity of runoff from the proposed WWTF will likely increase following construction. Construction of the WWTF will include an on-site stormwater management area to mitigate the quantity and quality of stormwater runoff from the site during construction and site operation. Peak runoff will not increase. The location, design, and operation of this area will be included in the NPDES General Stormwater Permit for Construction Activities for this site. Construction of the interceptor sewer, forcemain, and outfall sewer will create temporary land disturbance. As discussed in Item 16, a Project-specific erosion control plan will be prepared and implemented for construction activities and will include BMPs to minimize potential water quality impacts. The proposed underground utilities will not change the amount of impervious surface or impact water quality following construction.

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. Stormwater generated at the proposed WWTF will be conveyed via drainage swales and storm sewer to an on-site stormwater management area designed to treat runoff and reduce peak flows prior to discharging to a Hawk Creek tributary. Following treatment, the quantity and quality of stormwater generated from the proposed WWTF site is not expected to significantly impact the overall quantity and quality of water within Hawk Creek. Stormwater runoff from the portion of the interceptor sewer/forcemain corridor west of 10th Street Southwest will be directed toward Hawk Creek and the drainage ditch tributaries to Hawk Creek. Stormwater runoff from the remainder of the interceptor sewer will be directed toward the ditches leading to the South Fork Crow River. Stormwater runoff from construction of the forcemains will be directed into existing road side ditches and city street storm sewer system. As discussed in Item 16 and in Item 17a, appropriate erosion and sediment control measures will be implemented prior to, during, and after construction to minimize runoff and discharge of sediments to receiving waters. Because the interceptor sewer, forcemain, and outfall sewer will be installed underground, the site disturbance will be temporary. Significant impacts to receiving water bodies are not anticipated.


Dewatering is anticipated to accommodate installation of the underground piping. Dewatering discharges will be directed upgradient of temporary erosion controls to allow filtering. If dewatering discharges cannot be directed toward an existing filtering device, filter bags or temporary sedimentation ponds will be constructed to remove particulate prior to discharge to 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. The proposed WWTF is designed to collect and treat normal municipal sewage (residential, commercial, public, light industrial) and discharges from the JOTS. Table 18-1 shows the composition (loading) and quantity (flow) of influent wastewater to be treated at the site.

TABLE 18-1 DESIGN INFLUENT PARAMETERS OF PROPOSED WWTF

WWTF Average wet weather design flow (mgd) 7.51 Average dry weather flow (mgd) 4.92 Peak wet weather (mgd) 27.36 CBOD

• Annual average (pounds/day) 13,029 TSS

• Annual average (pounds/day) 8,984 Total Kjeldahl nitrogen

• Annual average (pounds/day) 2,548 Total phosphorus

• Annual average (pounds/day) 567 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 existing WWTF operates under NPDES/SDS Permit MN 0025259, which authorizes a discharge of treated effluent to Kandiyohi County Ditch #46. Kandiyohi County Ditch #46 becomes Hawk Creek a short distance from the existing WWTF outfall. The proposed WWTF will operate under the same NPDES/SDS Permit number as that of the existing WWTF, MN025259, and will discharge treated effluent to Hawk Creek approximately two miles downstream of the existing outfall (Figure 2). The existing outfall will be abandoned once the relocated WWTF becomes operational.

The proposed WWTF will include the following treatment units:

• Municipal wastewater will receive the treatment listed below: o Raw wastewater pumping o Fine screening (3 or 6 mm openings) o Extended aeration activated sludge o Chemical phosphorus treatment o Disinfection


o Effluent aeration

• Production-related wastewater from the JOTS facilities will receive the following treatment units: o Fine screening at the production facility o Flow equalization at the production facility o pH adjustment at the production facility o Dissolved-air flotation at the production facility o Extended aeration activated sludge o Disinfection o Effluent aeration

At the proposed outfall location, Hawk Creek is designated as a Class 7, 3C, 4A, 4B, 5, and 6 water of the state. The designated use shall permit aquatic recreation such as boating, canoeing, fishing and wading, preserve the ground water for a source of potable water supply, and protect the aesthetic qualities of the water. Hawk Creek eventually flows to the Minnesota River. Approximately 27 miles downstream of the proposed discharge point, the Class 7 designation changes to a Class 2B. The MPCA sets effluent limits in NPDES/SDS Permit that are intended to prevent the degradation of the receiving water. The effluent limits that the MPCA is proposing for this Project are shown in Table 18-2 below. The proposed WWTF will be designed to meet these effluent limitations and any other requirements contained in the NPDES/SDS Permit. Because the proposed Project will discharge to a Class 7 water, it does not meet the definition of a “significant discharge” per Minn. R. 7050.0185, subp. 2(G)(2), and the requirement for additional nondegradation review was not triggered.

TABLE 18-2 ANTICIPATED AVERAGE MONTHLY EFFLUENT LIMITS FOR PROPOSED WWTF

Effluent Parameter Limiting Concentration or Range 5-day CBOD 15 milligrams per liter (mg/L) TSS 30 mg/L Fecal Coliform Group Organisms

• May-October 200 organisms/100 ml Ammonia-Nitrogen

• December-March 5.0 mg/L pH 6.0-9.0 DO

• December-March 6.0 mg/L Total phosphorus 1 mg/L(1) Other Acute Whole Effluent Toxicity Testing Annual, to start on date of permit issuance (1) The effluent phosphorus limit ensures the discharge will comply with the Lower Minnesota

River Dissolved Oxygen Total Maximum Daily Load (TMDL) study implementation plan, as noted below.


Phosphorus The lower Minnesota River has been designated as impaired for low DO. 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, the decomposition process utilizes dissolved oxygen in the river, creating a shortage for other 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 DO impairment on the lower Minnesota River. Phosphorus reductions from WWTFs discharging to the Minnesota River Basin 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. It was issued on December 1, 2005, and will expire on November 30, 2010. Phase II will likely be implemented through a second permit after expiration of the Basin Permit. The Basin Permit authorizes the discharge of phosphorus from expanding WWTFs as long as the facility applies for coverage and operates in accordance with the provisions of the Basin Permit. The proposed WWTF project will, therefore, obtain coverage under both an individual NPDES/SDS Permit and under the Basin Permit. The Basin Permit contains mass phosphorus limits for WWTFs that discharge to the Minnesota River Basin, including the existing Willmar WWTF, that apply from May 1 to September 30 each year. The proposed Project will continue to comply with the Basin Permit and the individual NPDES/SDS Permit will require a year-round 1.0 mg/L effluent phosphorus limit. Table 18-3 summarizes the substantial phosphorus reductions that will be realized with the proposed Project.

TABLE 18-3 Phosphorus Loads from the Existing and Proposed WWTFs

Existing Proposed Reduction AWW design capacity flow (mgd) 5.04 7.51 --- Maximum phosphorus load (pounds/year) 101,005(1) 22,843(2) 77%

(1) Based on monitoring data that show the existing WWTF effluent contains an average 6.58 mg/L phosphorus concentration.

(2) Based on the year-round 1.0 mg/L effluent phosphorus limit to be applied to the proposed WWTF.

The City is aware that further phosphorus reductions may be required through Phase II of the implementation plan for the Lower Minnesota River Dissolved Oxygen TMDL. Mercury Effluent data for the existing WWTF indicate that the discharge has no reasonable potential to cause or contribute to an exceedence of the mercury water quality standard. Thus, no limit is proposed for this metal, though quarterly monitoring will continue.


The proposed WWTF will discharge to Hawk Creek. Eight reaches in Hawk Creek were designated as impaired for aquatic consumption due to mercury on the 2006 Impaired Waters list. On March 27, 2007, the U.S. Environmental Protection Agency approved the MPCA’s Statewide Mercury TMDL study. The implementation plan for the study addresses all of the Hawk Creek mercury impairment listings. For this reason, the eight listings are proposed for delisting on the 2008 Impaired Waters list, which is on public notice as of the drafting of this document (http://www.pca.state.mn.us/water/tmdl/tmdl-303dlist.html). Mercury is known to be present in municipal effluents and is primarily associated with TSS. After review of Project information, MPCA staff believes that the additional solids to be removed to comply with the phosphorus limit will also assure that TSS loads, and thus mercury present in the treated effluent, will be maintained or reduced from that discharged currently. Therefore, the proposed Project is not expected to contribute to previously identified impairments or cause new impairment listings.

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. Production-related wastewater from the JOTS will require pre-treatment prior to being discharged to the publicly-owned treatment facility. Wastewater generated by JOTS Benson Avenue and Willmar Avenue production facilities will receive pre-treatment at the Willmar Avenue facility. Production-related wastewater from JOTS will receive the following pre-treatment at the production facility:

- Fine screening - Flow equalization - pH adjustment - Dissolved-air flotation

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:

7 (seasonally variable)

minimum;

seasonally variable

average.

Bedrock: >200 minimum; >200 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. Ground water is expected to be perched within a shallow aquifer and seasonally variable. Geotechnical boring logs completed for this Project indicates up to two feet of black organic deposits overlying clayey alluvium and glacial till at varying depths. Measurable ground water was encountered within the boreholes at depths ranging from 10 to 48 feet below ground surface.


According to well driller logs in the area, there are no know sinkholes, shallow limestone formations, karst conditions, or other potential geologic hazards along the proposed interceptor and forcemain routes.

b. Describe the soils on the site, giving Soil Conservation Service 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. Soils data for Kandiyohi County was obtained through the U.S. Department of Agriculture Natural Resources Conservation Service National Cooperative Soil Survey using the Soil Survey Geographic Database. Soils maps show the primary soils along the interceptor sewer and the outfall sewer corridors include loams, clay loams, silty clay loams, and a combination of these soil types. The soils are underlain by loam to clay loam textures derived from glacial till, alluvium, or lacustrine deposits. Most of the corridor has 0 to 2 percent slope. Several small areas along the interceptor route and along the outfall route have soils with 2 to 6 percent slope. The primary soils along the forcemain corridor include loam, clay loam, silty clay loam and a combination of these soil types. Most of the forcemain corridor has 0 to 2 percent slope except for a small area at the south end of the forcemain which has 6 to 12 percent slopes. The primary soils at the proposed WWTF site are loam, silty clay loam, and a combination of these soil types. Most of the site has 0 to 2 percent slope. Several small areas at the WWTF site have 2 to 6 percent slopes. Measures will be taken during construction at the WWTF site to minimize any possibility of ground-water contamination. Accidental spills should be limited to small quantities of controlled substances. Any such spill will be cleaned up immediately as required to protect soil and ground-water resources. There will be limited opportunity for ground-water contamination during site operation, since the WWTF effluent and biosolids will be contained and not spread on the plant property. The proposed WWTF will include sealed storage tanks for chemicals located within containment basins. WWTF staff has routine maintenance procedures to ensure the reliability of the treatment equipment and the tanks and piping will be routinely inspected for leaks. Due to the temporary nature of the sewer line construction and the short duration the trench will be open, the potential for ground water contamination is considered low. Accidental spills should be limited to small quantities of controlled substances. Any such spill will be cleaned up immediately as required to protect soil and ground-water resources.

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. Construction activities will generate waste materials such as trees, fence wire and posts, aggregate base, bituminous pavement, concrete pavement, silt fence, salvaged equipment, pipe, metal, concrete structures, and wood. These materials will be disposed of by the contractor in accordance with applicable state and local rules and regulations.


Measures will be taken during construction of the underground sewers and the WWTF site to minimize any spills or generation of wastes. On-site receptacles will used during construction to collect and dispose refuse at a licensed facility, as needed. Portable toilets will be available during construction and periodically maintained, as needed. On-site storage of hazardous wastes is not expected during construction. Vehicular fuels will be transported to the site, as needed, and transferred directly to equipment, as needed. Accidental spills during construction should be limited to small quantities of controlled substances. Any such spill will be cleaned up immediately as required to protect soil and ground-water resources. During operation, biosolids from the treatment of municipal and industrial wastewater will be produced by the proposed WWTF. The proposed WWTF is expected to produce approximately 9.25 million gallons of biosolids at startup and 11.25 million gallons once it reaches its design capacity. Industrial biosolids will be thickened and stored as a liquid before off-site land application at MPCA-approved sites. Municipal biosolids will be generated by an extended aeration biological process, thickened, stored as a liquid, and land applied below ground surface at MPCA-approved sites. Solids generated by the fine screening of municipal wastewater will be washed and compacted before being hauled to a licensed landfill. These compacted solids will satisfy the paint filter test.

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.

Ferric chloride will be used to chemically precipitate phosphorus at the proposed WWTF. The ferric chloride solution will be stored in above-ground storage tanks within a building that was designed to serve as secondary containment to minimize the risk of spills. Sodium hypochlorite will be used for disinfecting the non-potable water supply system. The sodium hypochlorite solution will be delivered to the plant site in 55-gallon drums. Storage and pumping operations will occur inside a building. The drums will be stored on containment pallets to minimize the risk of spills. Magnesium hydroxide will be used to adjust the alkalinity of the JOTS wastewater during the treatment process. The magnesium hydroxide will be stored in an above-ground tank within a building that was designed to service as secondary containment to minimize the risk of spills.

The WWTF is required to prepare a SWPPP to inventory and manage on-site materials and pollutants in stormwater runoff during site operation. Implementing the SWPPP will minimize risk of discharges that could result in ground-water contamination.

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. In addition to the chemicals listed in Item 20b, a 700-gallon above-grade diesel tank and a 300-gallon above-grade gasoline tank will be located at the proposed WWTF to fuel WWTF vehicles. Storage tanks at the proposed WWTF are listed in Table 20-1.


TABLE 20-1

Storage Tanks Anticipated to be Present at the Proposed WWTF Qty Contents Description Volume

(gallons) Location Secondary

Containment 2 Ferric

Chloride Aboveground - High Density Polyethylene

7,100 Secondary Building Structure No. 250

Building designed to provide containment

2 Ferric Chloride

Aboveground - High Density Polyethylene

6,100 Secondary Building Structure No. 250


1 Magnesium Hydroxide

Aboveground - High Density Polyethylene

10,300 JOTS Selector Basin Structure No. 232


1 Diesel Fuel Aboveground - Steel tank w/concrete outer shell

4,000 Outside Standby Power Generator Building, Structure No. 205

Double wall tank construction

2 Diesel Fuel Aboveground – Steel tank

300 Inside Generator Building, Structure No. 205

Double wall construction with leak detection.

1 Diesel Fuel Aboveground- Steel tank

700 Fuel Storage Area, Structure No. 291

Double wall construction.

1 Gasoline Aboveground- Steel tank

300 Fuel Storage Area, Structure No. 291

Double wall construction.

Each of the two pump stations along the forcemain route will have an emergency back-up diesel-fueled generator located outside of the pump station building. The pump station at the JOTS Bensen Avenue facility will have a 300-gallon sub-base, double wall, steel tank. The pump station at the JOTS Willmar Avenue facility will have a 400-gallon sub-base, double wall, steel tank. Both tanks will be equipped with leak detection. The WWTF staff will have emergency response training and containment plans developed and accessible in case of any spills. In addition, the local fire department and emergency response personnel will be informed of the chemical storage facilities on site.

21. Traffic. Parking spaces added

at new WWTF:

21 Existing spaces at new WWTF (if project involves expansion):

0

Estimated total average daily traffic generated: 20 vehicles/day Estimated maximum peak hour traffic generated (if known) and its timing: NA 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. The proposed Project will have no significant impact on local traffic. The proposed WWTF will be located in an area with low traffic flow and no vehicle congestion. There will be 21 parking spaces at the proposed WWTF site to accommodate staff and visitors. This Project does not involve significant traffic or roadway improvements or significant increases to traffic. The existing biosolids transfer and storage facility, located on the proposed WWTF parcel, accepts biosolids generated from the existing WWTF via truck traffic. Integrating the proposed WWTF on the same parcel as the existing biosolids transfer and


storage facility will reduce the existing biosolid truck traffic on local roadways, because hauling between the WWTF and the transfer and storage facility is eliminated. During construction activities, varying numbers of vehicles and equipment will be mobilized. Impacts on area traffic will be minor, specific to the local construction zone, and of short duration. Traffic warning devices will be used during construction when necessary and appropriate.

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. Vehicle emissions associated with the construction and operations of this Project will not have a significant effect to air quality.

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 proposed WWTF will have one emergency generator to supply standby power in times of electrical power outages. Each of the two new pump stations will also have an emergency generator. The generators will run as necessary to operate the WWTF or pump station during a power outage. Air emissions from emergency power generation will be infrequent and not considered a significant emission source.

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.) Odor Construction equipment will generate exhaust odors. Construction will be limited to normal construction hours (daylight hours Monday through Saturday) to limit the impact of odors. The specifications for the Project will include dust control measures to minimize discomfort and inconvenience to local residents and businesses. Odor impacts will be temporary and will be generally confined to the immediate vicinity of the construction area. The design of the proposed WWTF includes approaches that will ensure that objectionable odors from the operation of the facility will not be a concern. The new WWTF will eliminate commingling of municipal and food processing wastewaters to avoid formation of volatile organic acids, and relocate the


treatment facility a far distance from residential neighborhoods, commercial districts, and other public areas. Considering the improved wastewater treatment technology and facility setbacks from adjoining properties, odor-related complaints are not expected. Noise There will be a temporary increase in noise generated by heavy machinery during the construction of the WWTF. Contractors will be required to comply with City noise ordinances. Construction will only be allowed during normal construction hours (daylight hours Monday through Saturday) and equipment will be required to have operable noise suppression devices (mufflers) to minimize noise impacts. Noise impacts will be temporary and will be generally confined to the immediate vicinity of the construction area. Operation of the treatment system components at the proposed WWTF is not expected to produce significant noise levels beyond the associated site boundaries. Dust Dust emissions will increase during construction. Dust impacts will be temporary and will be generally confined to the immediate vicinity of the construction area. Contractors will be required to use dust control measures (application of water to construction roads) during construction. 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 The SHPO was contacted in September 2006 for information regarding the presence of cultural resources in the proposed Project area. Following a review of the Project plans, the SHPO responded in a November 8, 2006, correspondence indicating that an archaeological survey was not required for this Project (Attachment C). In October 2006, prior to receipt of the SHPOs November 8, 2006, correspondence, Donohue and Associates retained Archaeological Research Services (ARS) to complete a Phase I Archaeological Assessment of the proposed WWTF and sewer corridors. A field inspection was completed on October 23-25, 2006, under the direction of Christina Harrison, principal investigator. It was preceded by a records and literature review that focused on the cultural resource files maintained for Kandiyohi County at the Minnesota Historical Society and the Office of the State Archaeologist. Additional ARS files were reviewed from an earlier cultural resource study conducted on the Willmar Municipal Airport property less than two miles north of the proposed WWTF (Harrison 1998).


The following is a summary of the findings:

• No archaeological resources were recorded within or immediately adjacent to the current Project area; however, Native American habitation and burial sites are common around most of the area lakes and have also been recorded along some of the connecting streams and on uplands overlooking the larger wetlands.

• A majority of the Project area, except for the wetlands, has been highly disturbed by decades of cultivation, past plow disturbance would have brought at least a sample of any archaeological evidence to the surface. Consequently, farmed areas were carefully inspected along transects spaced closely enough to provide complete survey coverage, generally no more than five meters apart. All results showed no evidence of artifacts present within the Project area. The investigator believes the general area has little, if any, archeological potential and that the soils have been deeply disturbed.

• Areas that are no longer farmed were reviewed for archaeological potential and found to be either too disturbed or too far from water to have potential for archaeological artifacts.

ARS concluded that no further Phase I survey was needed and that it is unlikely that the proposed Project would impact archeological resources. The Management Summary from the Phase I Cultural Resources Assessment is included with this EAW as Attachment D. The full report is available upon request.

Prime farmlands About 88 acres of prime cropland will be affected by the construction of the proposed WWTF and conveyance system. About 8 acres will be converted to lawns, landscaping, and structures. The remaining cropland will be restored as cropland. Other unique resources An existing wetland mitigation site is located on the proposed WWTF parcel. This site was constructed in 2003 to mitigate wetland impacts associated with expansion of the Willmar Municipal Airport located approximately one mile to the north. Future use of the wetland or associated buffer habitats are restricted by a conservation easement under permit conditions administered by the USACE under Section 404 of the Clean Water Act.

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. Construction and operation of the sewer corridors is not expected to significantly alter the existing visual surroundings. The sewers will be constructed underground and will not result in a visual impact. Visual impacts to be encountered during construction will be temporary and not considered a significant impact. Construction and operation of the proposed WWTF will create a visual impact. During construction, heavy equipment will be mobilized to the site and construction will continue for over two years. During operation, new buildings and lighting will occupy the local landscape and change the appearance of the local viewshed from agricultural to industrial. To mitigate visual impacts, an architect has been retained to design an architectural building style that will minimize visual impacts. In addition, a landscaping plan is being developed to screen areas with natural vegetation as well as naturalize the site with a variety of tree and shrub plantings around building foundations.


Lighting impacts will be mitigated by specifying directional lighting fixtures to focus above-ground lighting to the ground.

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 proposed WWTF parcel is located within the jurisdictional limits of the City (annexed in 2006) and is currently zoned government/institutional. The City acquired the proposed WWTF parcel in 1996 and has designated the site for relocation of the existing WWTF. The proposed Project is part of an overall comprehensive wastewater collection and treatment plan (described in the City of Willmar Facilities Plan dated May 1, 2006, available upon request).

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.) The Project is considered an upgrade of the existing public utility infrastructure. The proposed WWTF site and utility corridors are already served by roads; therefore, new road construction is not required to access these areas. The pump stations will require electricity that is easily accessible at both sites. The proposed WWTF site will require electricity, natural gas, and telephone. This infrastructure will be extended to the proposed plant site from the nearest utility location to minimize environmental disturbance. The purpose of the WWTF expansion is to allow new development in the service area. Although new development is expected to continue in the service area, it is not anticipated that this Project will directly facilitate the need for new development or public investment in new roads, municipal water and sewer lines, or other utilities.

29. Cumulative impacts. Minn. R. 4410.1700, 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). Enabled Development This proposed Project is part of the comprehensive wastewater plan for the City. Figure 3 shows the anticipated future service area for the proposed Project. Increased development will likely result in increased traffic, air pollution, stormwater runoff, and the generation of additional solid waste. As residential and commercial areas expand, the amount of farmland, open space, and wildlife habitat in the area will decrease. Though the City anticipates that growth will occur within this area and that growth will be serviced by the proposed WWTF, there are very few projects that will occur within the reasonably


foreseeable future for which a basis of expectation has been laid. The City currently has one request to annex 12 acres of land approximately 0.25 miles north of the interceptor around 15th Street. Other potential future development projects are dependent on local economics, and the timing of future development is uncertain. Thus, it is difficult to determine how such development may combine with the proposed Project and present cumulative potential effects. If future development projects are large enough, they will require environmental review and potential for cumulative effects will be assessed through that review. Potential cumulative effects from future development will be mitigated through enforcement of local, state, and federal ordinances and regulations. Individual development projects throughout the City will be subject to project-specific environmental review and permitting. The City has a stormwater ordinance in place that regulates stormwater quality and quantity. In addition, the City is in the process of obtaining a Municipal Separate Storm Sewer (MS4) Permit. The SWPPP for that Permit is on public notice as of the drafting of this document. The MS4 Permit is designed to reduce the amount of sediment and pollution that enters surface and ground water from storm sewer systems to the maximum extent practicable, and is expected to work with the stormwater ordinance to mitigate cumulative potential effects due to stormwater runoff from existing and future development. Water Quality The proposed Project is located within the Hawk Creek watershed which is part of the Minnesota River basin. The Hawk Creek subwatershed is approximately 221,043 acres. The total watershed, including the Chetumba Creek subwatershed, is approximately 623,105 acres. As discussed in Item 18b, the proposed Project is not expected to cause or contribute to any water resource impairments. The proposed Project will operate under an NPDES/SDS Permit whose effluent limits will be set at levels that ensure that the Project does not cause or contribute to water quality impairments either individually or cumulatively with other sources in the watershed. The potential for significant cumulative effects to water quality or to aquatic organisms from this proposed Project is not expected. Water Quantity The proposer hired Donohue and Associates to determine the effect the discharge from the proposed WWTF would have to Hawk Creek during peak flow events for two worst case scenarios: a 100-year flood event and heavy runoff from spring thaw. Information used in the analysis included stream gauge data collected by the Hawk Creek Watershed Project from gauging stations in Priam and Maynard, stream flow vs. depth relationships developed by MPCA hydrologists, and sewer flow data collected from flow monitoring studies. Data used to estimate flows during heavy runoff from spring thaw came from mid to late-March 2001, a year that people living in the area said was one of the worst years for spring flooding. The analysis showed that peak flows during spring thaw are more significant than peak flows during heavy rainfall events. The Priam gauging station, two miles downstream from the proposed WWTF outfall location, showed a spring flow depth increase of 2.9 inches due to maximum peak future flows from the proposed WWTF. The Maynard gauging station, the next downstream gauging station, showed a spring flow depth increase of 1.2 inches. These potential increased water depths would be contained by the Priam (10-foot) and Maynard (25-foot) banks of Hawk Creek. The proposed WWTF is expected to have an even smaller impact on water depth further downstream from these two communities. Donohue and Associates concluded that the proposed WWTF is not expected to have a significant effect on Hawk Creek’s depth. The consulting engineer for Chippewa County (southwest of Kandiyohi County in which Priam, Maynard, and other downstream communities are located) has reviewed Donohue and Associates’ report and concurs with its findings. The letter from I&S Engineers & Architects, Inc. to Chippewa County is included in this EAW as Attachment E.

11075 SEPTEMBER 2007 WILLMAR, MINNESOTA

FIGURE 1: PROJECT LOCATION MAP

CITY OF WILLMARWASTEWATER TREATMENT FACILITY & CONVEYANCE SYSTEM

PROJECT LOCATION

11075 SEPTEMBER, 2007

FIGURE 5: AERIAL PHOTOGRAPH – PROPOSED WWTF LOCATION

CITY OF WILLMARWASTEWATER TREATMENT FACILITY & CONVEYANCE SYSTEM

WILLMAR, MINNESOTA

BiosolidsStructures

Brush and CompostFacility Trap and

Skeet Range

Property Line (TYP)

Coun

tyDi

tch19

CountyRoad 116

Township Range SectionReason for Impact

119N 35W 15 no wetlands - -119N 35W 16 16-1 No -

16-2 No -16-3 No -16-4 No -16-5 No -

119N 35W 19/30 19-1 Yes 0.01 Collection System19-3 No -W3 Yes 1.80 Collection SystemW5 Yes 0.16 Collection SystemW6 Yes 0.41 Collection System

119N 35W 20/29 20-1 No -20-2 Yes 0.06 Collection System20-3 No 0.03

20-4, W7 Yes 0.29 Collection SystemW8 Yes 1.38 Collection SystemW9 Yes 0.06 Collection SystemW10 Yes 0.48 Collection SystemW11 Yes 0.19 Collection System

119N 35W 21 21-1 No -21-2 No -21-3 No -21-3a No -21-4 Yes 0.09 Collection System21-5 No -21-6 No -21-7 No -21-8 No -21-9 Yes 0.03 Collection System21-10 No -21-11 Yes 0.09 Collection System21-12 No -

119N 35W 22 no wetlands - -119N 35W 23 no wetlands - -119N 36W 23 23W-1 No -

23W-2 Yes 0.51 New WWTF23W-3 No -23W-4 No -23W-5 No -23W-6 No -

Mitigation Area Yes - Increase Area for New Mitigation119N 36W 24 24-2 No -

24-3, W1 Yes 0.41 Collection SystemW2 No -W4 Yes 0.18 Collection System

FIGURE 9: WETLAND IMPACT SUMMARY

LocationWetlandIdentifier

Impacted?(Yes/No)

AreaImpacted

(acres)

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