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Becker Wastewater Treatment Facility Upgrade and Expansion ... · Becker Wastewater Treatment Facility Upgrade and Expansion Environmental Assessment Becker, Minnesota Worksheet 2

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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: Becker Wastewater Treatment Facility Upgrade and Expansion 2. Proposer: City of Becker, Minnesota 3. RGU: Minnesota Pollution Control Agency Contact Person Karla Eggink, P.E. Contact Person Dana Vanderbosch and Title Public Works Director and Title Project Manager Address 12060 Sherburne Avenue, Box 250 Address 520 Lafayette Road North Becker, Minnesota 55308 St. Paul, Minnesota 55155 Phone (763) 261-4449 Phone (651) 297-1796 Fax (763) 261-4385 Fax (651) 297-2343 4. Reason for EAW Preparation:

EIS Scoping

Mandatory EAW

X

CitizenPetition

RGU Discretion

Proposer Volunteered

If EAW or EIS is mandatory give EQB rule category subpart number and name: Minn. R. 4410.4300,

subp. 18(B) 5. Project Location: County Sherburne City Becker SE 1/4 NE 1/4 Section 31 Township T34N Range R28W

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Figures and Attachments for the EAW:

Figure 1 Map showing the general project location in Sherburne County, Minnesota; Figure 2 United States Geological Survey 7.5 minute, 1:24,000 scale map indicating project boundaries; Figure 3 Overall site plan; Figure 4 New domestic treatment train site plan; Figure 5 National Wetland Inventory (NWI) map; and Figure 6 Site soils map. Attachment A Minnesota Department of Natural Resources (DNR) Natural Heritage and Nongame

Research Program Response Letter dated November 23, 2005; and Attachment B Minnesota Historical Society’s State Historic Preservation Office (SHPO) letter dated

November 18, 2005. 6. Description:

a. Provide a project summary of 50 words or less to be published in the EQB Monitor. The city of Becker (City) in Sherburne County, Minnesota, is proposing to expand the treatment capacity of its wastewater treatment facility (WWTF) from an average wet weather (AWW) design flow of 0.85 million gallons per day (mgd) to 2.15 mgd. Certain current mass loading limits will be “frozen.” Treated effluent will continue to discharge to the Elk River. In addition to the EAW, the MPCA’s 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 Robin Novotny, at (218) 828-6114.

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 is located in the southern portion of Sherburne County in central Minnesota. It is in close proximity to Interstate 94 and Highway 10, sixteen miles from St. Cloud and forty-five miles from Minneapolis (Figure 1). The City’s WWTF includes two separate treatment trains – one for domestic wastewater (including light commercial), and one for industrial wastewater from Liberty Paper Incorporated. The existing domestic treatment train consists of a coarse bar screen, influent pump station, fine screen, four rotating biological contactors (RBCs), two final clarifiers, ultraviolet (UV) disinfection and effluent pump stations. Alum and polymer are added to aid in the removal of phosphorus. Sludge from the wastewater treatment process is mechanically thickened and then goes through a heated lime pasteurization process. The resulting biosolids are land applied. The existing domestic treatment train is designed to treat an AWW design flow of 0.40 mgd.

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The industrial treatment train consists of screening and nutrient addition, an industrial influent pump station, two trickling filters, anaerobic selector tank for biological phosphorus removal, two oxidation ditches, two final clarifiers, a sludge pumping building, two waste sludge holding tanks and a sludge processing building with two belt filter presses. It is designed to treat an AWW design flow of 0.45 mgd. The two treatment trains operate in parallel and are combined after the domestic flow has passed through the UV disinfection channels. The continuous discharge of treated effluent from one outfall to the Elk River (Figures 2 and 3) is authorized by NPDES/SDS Permit No. 025666. Proposed Project Domestic Treatment Train. The proposed project entails the construction of an expanded domestic treatment train that will continue to operate in parallel with the industrial treatment train. The AWW design flow capacity for the domestic treatment train will increase from 0.40 to 1.55 mgd. Three decommissioned wastewater lagoons located on site are in the process of abandonment per a compliance schedule in the existing Becker WWTF NPDES/SDS Permit. Construction of the proposed domestic treatment train structures will occur where Lagoon 1 is currently situated (Figure 3) and will include the following major structures and unit processes (Figure 4):

Lift Station. Approximately 2,300 linear feet of 15-inch and 20-inch gravity sewer will replace the existing lift station (called the ‘L2 lift station’) and force main. The gravity pipe will be installed using open trenching. Raw domestic wastewater will be pumped to the WWTF via a new influent lift station. The list station will consist of three pumps, with a provision for a forth when flows necessitate its addition. The flow will travel to the new headworks building for preliminary treatment. Preliminary Treatment. Preliminary treatment in the domestic treatment train will include a mechanically cleaned bar screen to remove large and stringy objects from the wastewater, such as sticks, plastic objects, and rags. Screenings will be washed and compressed before being loaded in a container for disposal at a solid waste disposal facility. A vortex grit removal system will remove sand, grit and other materials with high specific gravities from the waste stream. The grit removed will be washed in a grit cyclone and loaded into a container for disposal at a solid waste disposal facility. Secondary Treatment. After preliminary treatment, the wastewater will flow to an anaerobic oxidation basin to assist in biological phosphorous removal, flow will then enter one of two oxidation basins for secondary treatment, which will provide an environment and adequate time for microorganisms to interact with the wastewater stream in the basins and consume organic materials. Alum and polymer will provide a chemical backup to aid in the removal of phosphorus. Final Clarifiers. After the oxidation basins, two final clarifiers help provide separation of the water from the organisms. The flow of the treated wastewater is slowed in the clarifiers to facilitate settling of micro-organisms to the bottom of the clarifiers. The micro-organisms that settle in the clarifiers are either returned to the oxidation basins to help maintain the proper balance of micro-organisms for treatment or are transferred to the sludge process.

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Tertiary Filters. After passing though the final clarifiers, the flow will be put through an additional polishing step and treated via cloth media disk filters to remove additional solids, such as organics, phosphorus and mercury, prior to discharge. UV Disinfection. The filtered effluent will be disinfected by using a UV disinfection process. The wastewater will flow through UV light banks to inactivate or kill off any bacteria present and help protect the receiving water. Effluent Aeration. After disinfection, the domestic wastewater will combine with the industrial wastewater for a final aeration step. Aeration will incorporate oxygen into the treated effluent prior to discharge, which, in turn, will help protect the dissolved oxygen level in the Elk River. Discharge. A new 30-inch ductile iron discharge pipe 180 feet long and outfall structure will replace the existing discharge pipe and outfall. The new pipe will terminate adjacent to the existing discharge pipe, which will be abandoned in place and plugged. The new outfall structure will consist of a pipe terminus with a screen to prevent access and additional riprap at the outfall to prevent ditch erosion. The gravity pipe will be installed using open trenching.

A new unloading station for material accumulated when City staff clean out sewers, catch basins and/or lift stations will also be constructed. The truck will dump its contents onto a sloped pad. A fabricated metal screen will help to separate solid materials from liquids and the liquids will be routed via gravity sewer to the lift station and then to the head of the proposed domestic treatment train. Solid, gritty material will settle on the pad and be removed with the front-end loader. The proposed project will require the demolition of certain existing structures that include the interior mechanicals and equipment in the existing RBC building to provide space for administrative and maintenance space. The existing domestic final clarifier and sludge pump station mechanicals will also be removed. The project will also provide an odor control system with biofilter treatment for the new domestic headworks facilities, and the existing industrial headworks building and packed towers. Industrial Treatment Train. The proposed project will make minor improvements to the industrial treatment train. In addition to the odor control mentioned above, the changes will include return activated sludge (RAS) distribution pipe modifications, instrumentation changes to the industrial influent pump station, minor modifications to the existing UV and industrial RAS/waste activated sludge (WAS) pump station, concrete repair to the interior of the industrial headworks building, and extending effluent piping to the combined effluent aeration basin. According to the existing Becker WWTF NPDES/SDS Permit, the AWW design flow capacity of the industrial treatment train is 0.45 mgd. This treatment capacity was re-rated by MPCA staff several years ago, when it was determined that the treatment capacity of the industrial treatment train is actually 0.60 mgd; however, the NPDES/SDS Permit has never been modified to reflect this re-rating process. The proposed Project will include modifying the AWW design flow capacity from 0.45 to 0.60 mgd in the NPDES/SDS Permit to reflect the re-rating. Considering the expansion of the domestic treatment train and the re-rating of the industrial treatment train, the combined permitted treatment capacity for the WWTF will increase from 0.85 mgd to 2.15 mgd as a result of the proposed project.

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Physical manipulation of the existing site will include: temporary storage of the excavated materials on site; backfilling, compacting, and grading the excavated material on site; grading and seeding disturbed areas; and temporary de-watering during construction. Installation of the gravity sewer will also require: excavation of existing soils; temporary storage of the excavated materials; backfilling; compacting and grading the excavated soil after the pipe has been installed; and seeding disturbed areas. The proposed project will most likely begin in late 2006 and be completed early in 2008.

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 purpose is to provide a reliable means to treat wastewater as the City grows, while continuing to allow the City to consistently comply with the Becker WWTF NPDES/SDS Permit. The beneficiaries of the project will be the citizens, business owners and employees, and visitors of the City.

d. Are future stages of this development including development on any outlots planned or likely to happen? Yes No

If yes, briefly describe future stages, relationship to present project, timeline and plans for environmental review. The estimated population within the WWTF service area in 2006 is approximately 4,500. The City believes that the proposed project will serve for the next ten years, when the population is estimated to reach 13,250. Another expansion may be needed near the year 2017. Due to uncertainties pertaining to the growth of the City and when further treatment capacity will be needed, anticipated future expansions cannot be fully described in this EAW. Environmental review for this next expansion, if required, will occur at a later time.

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.

7. Project Magnitude Data Total Project Area (acres) 18.5 or Length (miles) Number of Residential Units: Unattached Attached maximum units per building Commercial/Industrial/Institutional Building Area (gross floor space): total square feet Indicate area of specific uses (in square feet): Office Manufacturing Retail Other Industrial See below Warehouse Institutional Light Industrial Agricultural Other Commercial (specify) Building height 2 stories If over 2 stories, compare to heights of nearby buildings

TABLE 7-1

AREA OF PROPOSED BUILDINGS Building Area in square feet

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TABLE 7-1 AREA OF PROPOSED BUILDINGS

Building Area in square feet Maintenance building (RBC building) 3,100 UV building 750 RAS/WAS building 1,250 Headworks building 1,150 Filter building 1,200

The tallest of the new buildings will be about 25 feet above natural grade. This height is approximately 8 feet taller than the tallest existing building and about 10 feet below the top elevation of the packed towers, the tallest existing structures on the WWTF property.

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 U.S. Army Corps of Engineers (USACE)

Section 404 Permit for dredging and filling of navigable waters/jurisdictional wetlands To be submitted

MPCA NPDES/SDS Permit modification Submitted, under review

MPCA Plans and Specification Review Submitted, under review

MPCA NPDES General Stormwater Permit for Construction Activities To be submitted

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

DNR Natural Heritage and Nongame Database Review Completed

DNR General Permit 97-0005 for Temporary Water Appropriation To be submitted

SHPO Concurrence on Findings of Cultural Resource Impacts Completed

Sherburne County Soil and Water Conservation District (SWCD) Grading Permit To be submitted

Sherburne Country Biosolids Land Application To be submitted

City of Becker Certificate of Wetlands Conservation Act (WCA) Exemption To be submitted

City of Becker Building Permit To be submitted

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9. Land use. Describe current and recent past land use and development on the site and on adjacent lands.

Discuss project compatibility with adjacent and nearby land uses. Indicate whether any potential conflicts involve environmental matters. Identify any potential environmental hazards due to past site uses, such as soil contamination or abandoned storage tanks, or proximity to nearby hazardous liquid or gas pipelines. The new WWTF structures will be constructed on land that the City owns and on which one of the soon-to-be-abandoned wastewater lagoons is located. The area is zoned for industrial use. The gravity sewer, which will replace the existing lift station and force main, will be installed on a combination of City property and existing City easement between two private residences. Zonings adjacent to the project sites include primarily residential, commercial, and industrial. The land to the south, west and northeast contains residential developments. There are homes located within several hundred feet of the WWTF. Land adjacent to the existing WWTF on the east and north are areas zoned as protected land use, river ways (Elk River), and wetland areas.

There are no known areas of soil contamination, abandoned storage tanks, or nearby hazardous liquid or gas pipelines within the Becker WWTF expansion project site.

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

Before After Before After Types 1-8 wetlands Lawn/landscaping 5.0 6.6 Wooded/forest Impervious Surfaces 1.7 2.6 Brush/grassland 2.5 0.0 Wastewater lagoons Cropland TOTAL 9.2 9.2

The estimates above do not include activity that will be undertaken to decommission the existing wastewater lagoons, as the requirement to remove the sludge within those lagoons is stipulated through a compliance schedule in the existing NPDES/SDS Permit. The ponds total approximately 15 acres in size.

11. Fish, Wildlife, and Ecologically Sensitive Resources. a. Identify fish and wildlife resources and habitats on or near the site and describe how they would be

affected by the project. Describe any measures to be taken to minimize or avoid impacts. Wildlife in the vicinity of the proposed site primarily consists of species native to central Minnesota. Species include deer, squirrels, rabbits, small mammals, snakes, turkeys, songbirds, amphibians, raptors, fish, and waterfowl. Geese inhabit the existing wastewater lagoons at the Becker WWTF during the fall season. Since the existing wastewater lagoons are in close proximity to the Elk River and adjacent wetlands, the wildlife implications of abandoning the lagoons and building the expansion on that site are expected to be minimal. The NPDES/SDS Permit to be issued to the WWTF will contain and enforce effluent limits and operating conditions intended to protect fish and wildlife living in and utilizing the Elk River.

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Treated effluent is discharged to a small unnamed ditch, flows to wetlands that border the Elk River and then to the Elk River. The discharge point is approximately 700 feet from the river. A new discharge pipe and outfall structure will be constructed on the bank of the unnamed ditch. The existing discharge pipe and outfall structures will be abandoned in place. This work will require an NPDES General Stormwater Permit for Construction Activity, which is expected to mitigate potential effects of erosion and sedimentation from construction activities near wetlands and the Elk River.

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 20060375 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. The DNR has determined that, based on the nature and location of the proposed project, they do not believe the project will affect any known occurrences of rare features. The letter is included as Attachment A.

12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration (dredging, filling, stream diversion, outfall structure, diking, and impoundment) of any surface waters such as a lake, pond, wetland, stream or drainage ditch? Yes No If yes, identify water resource affected. Describe alternatives considered and proposed mitigation measures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the water resources affected are on the PWI. A new discharge pipe and outfall structure will be needed since the existing discharge pipe is not sized for the proposed flow increase. The domestic treatment train structures will also be moved, necessitating a re-routing of the discharge pipe. The new discharge pipe will be a 30-inch ductile iron pipe, 180-feet long, and will be installed using open trenching. It will terminate adjacent to the existing outfall pipe, which will be abandoned in place and plugged. The outfall structure will consist of a pipe terminus with a screen to prevent access and additional riprap at the outfall to prevent ditch erosion. According to the NWI map (Figure 5), the outfall work will occur very near or slightly inside a wetland classified as PEMC (Palustrine emergent seasonally flooded shallow marsh). Based on the NWI map we have, the area of the construction that potentially could be in the wetland is approximately 0.025 acres, based on a 15-foot wide trench. Prior to construction, the area near the new discharge pipeline alignment will be delineated by the Sherburne County SWCD using methods described in the 1987 USACE Wetland Delineation Manual. The SWCD will stake the wetland boundary and the City will include the boundary on the site plan. If the proposed outfall pipe is in a wetland area, the City will evaluate whether or not the discharge pipe can be moved to minimize the area of the wetland that will be disturbed. If wetlands are present and cannot

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be avoided, this work would require several permits including a Section 401 Certification from the MPCA, a Section 404 permit from the USACE, and a Certificate of WCA Exemption from the local governmental unit – the City. Since pipeline installation would result in the temporary disruption of wetlands for the purpose of installing pipeline, mitigation would consist solely of restoration of disturbed wetlands. Original grade contours would be restored after construction and, therefore, pre-construction drainage patterns would not be anticipated to be altered by the project. Wetland vegetation would be restored by seeding with a native wetland seed mix. Soil erosion control measures that will be required per the NPDES General Stormwater Permit for Construction Activity during construction of the new discharge pipe and outfall structure to minimize potential impacts to nearby wetlands and the Elk River are described in Items 16 and 17 of this EAW. The reader may note that the NWI map indicates a PUBKx (Palustrine unconsolidated bottom, artificially flooded, excavated) wetland in the area of the proposed project. This wetland is actually Lagoon 1, which is in the process of being decommissioned. There are no wetlands or lakes identified by the DNR as public waters within the project vicinity.

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. A Water Appropriation Permit from the DNR is required for all users withdrawing more than 10,000 gallons of water per day or 1 million gallons per year. The City anticipates that the construction area will need to be dewatered and that a Temporary Water Appropriation Permit from the DNR will be needed. It is expected that the water pumped for dewatering purposes would be of relatively high quality, as the well heads typically used are very fine and prevent sediment uptake by the pumps; however, the contractor will be required by permit to allow any particulates to settle in a tank before discharging the ground water. All discharges would be in accordance to the Temporary Water Appropriation Permit from the DNR. The new buildings will be connected to the public water supply so a new potable water well will not be needed.

14. Water-related land use management districts. Does any part of the project involve a shoreland zoning district, a delineated 100-year flood plain, or a state or federally designated wild or scenic river land use district? Yes No If yes, identify the district and discuss project compatibility with district land use restrictions.

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.

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16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: 2.5 acres; 50,000 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.

The project proposer will be required to obtain an NPDES General Stormwater Permit for Construction Activities from the MPCA to control erosion and runoff during construction. This permit must be obtained prior to commencing any land-disturbing activities (i.e., clearing, grading, filling and excavating) at the site. The permit specifically requires implementation of best management practices (BMPs). Construction plans will include BMPs, such as the following:

• scarifying only those portions of the site actively under construction; • placing silt fencing and bale checks down slope of any land that is graded; • rocked entrances; • overflow swales lined with erosion protection mats; • grading that is part of the construction project will be no greater than a 3:1 slope; and • seeding and re-vegetating disturbed areas as soon as possible.

Measures to be used in addition to those listed previously may include check dams, biologs and/or stilling basins. Minimizing disturbance and phasing of the proposed project, along with diligent temporary stabilization of all slopes and areas of exposed soil, will be necessary to prevent erosion and the discharge of sediment to state waters. Disturbed areas will be seeded and stabilized as soon as possible after construction. A fiber blanket or hydraulic seeder may be used. The project consists of construction of several new structures and buildings, installation of gravity sewer pipe and a new discharge pipe, and involves general site work. The majority of the soil excavated to install the pipe will be returned to the construction trenches after placement of underground structures.

17. Water Quality – Surface-water Runoff. a. Compare the quantity and quality of site runoff before and after the project. Describe permanent

controls to manage or treat runoff. Describe any storm-water pollution prevention plans. Management of stormwater generated at the project site is required. The NPDES General Stormwater Permit for Construction Activities will have specific requirements for the treatment and overall management of industrial stormwater prior to discharge from the site. The permit will also require that a Stormwater Pollution Prevention Plan (SWPPP) be developed to manage pollutants in stormwater runoff from the site that will occur during construction and after construction is complete. The SWPPP is a detailed plan that will identify all sources of possible stormwater contamination for the project, provide an inventory of exposed significant materials, evaluate facility areas for exposure of significant materials to stormwater, describe structural and non-structural BMPs to be used to minimize contamination of stormwater, develop a preventive maintenance program, develop a spill prevention and response procedure, develop schedules for routine inspections of BMPs, and identify personnel responsible for implementing and managing the SWPPP. SWPPP and BMP implementation strategies must be prepared prior to submitting a permit application.

In general, high stormwater flow areas will be protected during construction with turf reinforcement

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mats. The quantity of runoff will increase slightly as new access roads at the WWTF will increase the impervious area by approximately 0.9 acres. After construction, the area will be vegetated and sloped gradually towards the wetland buffer between the WWTF property and the Elk River, so runoff should mostly percolate into the ground. The quality and quantity of site runoff is not expected to change significantly post-construction from what it is currently.

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. Local stormwater from the area is currently directed through a natural wetland buffer to the Elk River. From the Elk River, water flows to Orono Lake and then to the Mississippi River. As discussed in Item 16, erosion and sediment control measures will be implemented prior to, during, and after construction to control the quantity and quality of the runoff. Storm drainage to the existing system will continue to be discharged in the same manner. The quality of site runoff is not expected to change significantly post-construction from what it is currently.

18. Water Quality – Wastewater. a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewater

produced or treated at the site. Domestic Wastewater The domestic wastewater treatment train treats all residential and commercial wastewater from the City. The treatment capacity of the domestic treatment train will increase from 0.40 mgd to 1.55 mgd. The composition of waste treated through the domestic wastewater treatment train at the Becker WWTF is not expected to change as a result of the proposed project. Table 18-1 shows projected future flows and loadings based on historical data.

TABLE 18-1

ANTICIPATED FLOWS AND LOADINGS FOR THE DOMESTIC TREATMENT TRAIN

Parameter Value AWW design flow 1.55 mgd Average dry weather flow 1.25 mgd Carbonaceous Biochemical Oxygen Demand (CBOD)

245 mg/L

Total Suspended Solids (TSS) 275 mg/L Ammonia (NH3-N) 25 mg/L Total phosphorous 8 mg/L

Industrial Wastewater The existing Becker WWTF also includes a treatment train for high strength industrial wastewater from Liberty Paper, Inc. The average flow and influent composition is shown in Table 18-2. Based on available capacity in the industrial treatment processes, the industrial train can treat 0.60 mgd. The composition of waste treated through the industrial wastewater treatment train at the Becker WWTF will not change as a result of the proposed project. The City does have a signed industrial wastewater agreement with Liberty Paper, Inc., that places limits on the wastewater sent to the

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industrial treatment train. Those limits are shown in Table 18-2 below.

TABLE 18-2 LIMITS FOR WASTEWATER RECEIVED BY THE INDUSTRIAL

TREATMENT TRAINParameter Monthly Maximum Daily Maximum Flow 0.6 mgd 0.7-0.9 mgd CBOD 9,100 lbs/day 12,740 lbs/day TSS 1,000 lbs/day 2,000 lbs/day NH3-N 500 lbs/day 750 lbs/day Total phosphorous 40 lbs/day 60 lbs/day

Table 18-3 shows projected future flows and loadings for the industrial treatment train based on historical data.

TABLE 18-3 ANTICIPATED FLOWS AND LOADINGS FOR THE INDUSTRIAL

TREATMENT TRAIN Parameter Value Average flow 0.60 mgd CBOD 2,425 mg/L TSS 250 mg/L NH3-N 0 mg/L Total phosphorous 0 mg/L

b. Describe waste treatment methods or pollution prevention efforts and give estimates of composition

after treatment. Identify receiving waters, including major downstream water bodies, and estimate the discharge impact on the quality of receiving waters. If the project involves on-site sewage systems, discuss the suitability of site conditions for such systems. The proposed WWTF will consist of pretreatment through screening and grit removal, activated sludge with biological phosphorus removal, secondary clarifiers, tertiary filters and UV disinfection. Sludge will be dewatered and pasteurized to produce a Class A biosolids. Stabilized biosolids will be stored on site and later land applied to MPCA-approved agricultural land. Treated effluent will be discharged through a new outfall structure to an unnamed ditch, which flows to the Elk River, a class 2B, 3B, 4A, 4B, 5, and 6 water of the state, approximately 700 feet from the discharge point. The designated use shall permit the propagation of and maintenance of a healthy community of cool and warm water sport or commercial fish and associated aquatic life, and their habitats. The water shall be suitable for aquatic recreation of all kinds, including bathing, for which the water may be usable. The Elk River eventually flows to Orono Lake and then to the Mississippi River. The MPCA will set effluent limits in the NPDES/SDS Permit intended to prevent the degradation of the receiving waters. The WWTF will be designed to meet the effluent limitations and any other requirements contained in the NPDES/SDS Permit. The MPCA has completed its review of the project proposal and has proposed the following effluent limits for the proposed WWTF’s discharge:

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TABLE 18-4

ANTICIPATED EFFLUENT LIMITS FOR PROPOSED WWTF Effluent Parameter Limiting Concentration or Range 5-day Carbonaceous BOD (BOD5)

• Summer/winter 15 milligrams per liter (mg/L) • Summer/winter1 80.4 kilograms per day (kg/day) • Fall/spring 25 mg/L • Fall/spring1 80.4 kg/day

TSS1 • 30 mg/L • 96.4 kg/day

Fecal Coliform Group Organisms • April-October (applicable to

domestic treatment train only) 200 organisms/100 ml

pH 6.0-9.0 Ammonia-Nitrogen

• June-September 3.0 mg/L • June-September 24.4 kg/day • October-November 29.0 mg/L • December-March 5.0 mg/L • April-May 29.0 mg/L

Total Phosphorus1 • 1 mg/L • 3.2 kg/day

Mercury Monitor quarterly Other Chronic Whole Effluent Toxicity Testing Quarterly, to start on date of initiation operation

1The City of Becker has voluntarily accepted mass limits for BOD5, TSS and phosphorus that are identical to mass limits in the current Becker WWTF NPDES/SDS Permit No. 025666. In other words, the mass limits for those parameters will be “frozen” to current levels. In addition to the effluent limits above, the proposer will conduct in-stream monitoring from June through September to confirm that the summer effluent limits are protective of the Elk River’s dissolved oxygen standard. Mercury. The segment of the Elk River into which the proposed WWTF is designated as impaired for aquatic consumption due to mercury. Mercury is known to be present in municipal effluents and is primarily associated with TSS. As mentioned above, the City has voluntarily accepted to freeze the mass of TSS allowed to be discharged from the proposed WWTF from that current permitted to be discharged. The MPCA staff anticipates the freezing of the TSS mass limit, in addition to the additional solids removal that will accompany compliance with the effluent phosphorus concentration and mass limits, will also aid in assuring that TSS loads do not increase. Therefore, an increase in mercury from the proposed project is not anticipated.

c. If wastes will be discharged into a publicly owned treatment facility, identify the facility, describe any pretreatment provisions and discuss the facility’s ability to handle the volume and composition of

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wastes, identifying any improvements necessary. Not applicable.

d. If the project requires disposal of liquid animal manure, describe disposal technique and location and discuss capacity to handle the volume and composition of manure. Identify any improvements necessary. Describe any required setbacks for land disposal systems. Not applicable.

19. Geologic hazards and soil conditions. a. Approximate depth (in feet) to Ground water: 5 minimum; 14.7 average. Bedrock: >50 minimum; 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. There are no known sinkholes, shallow limestone formations or karst conditions in the proposed construction areas.

b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity and potential for ground-water contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. Thirteen borings were obtained on the project site. The surface is 0.4 feet to 3.8 feet of topsoil fill consisting of dark brown and black silty sands with organics (Figure 6). Below the topsoil is fill or possible fill consisting of a mixture of dark brown, gray, and black silty sand, sandy silt, and clayey silt, to depths 0.8 feet to 9 feet below grade. Underlying the fill in borings 1 and 8 through 13 is a possible buried topsoil layer consisting of black sandy clay, sandy silt, and clayey silt with organics, to depths of 7.3 to 14.7 feet below grade. An interbedded strata of sand, silt, and clay was found to the boring termination depths (15-50 feet). The cohesive and semi-cohesive soils were of firm to very stiff consistency, with N-values ranging from 6 to 19 and moisture contents from 16 percent to 35 percent. The naturally-occurring, non-organic granular soils were loose to dense, with N-values ranging from 4 to 32. In boring 6, cobbles and/or boulders, may exist at depths of about 4 to 6 feet below grade. There is little potential for ground water contamination. All wastewater will be contained in the existing facilities during construction and in the new facilities following construction. Any chemicals required for construction purposes will be handled in accordance with acceptable safety standards so that the chance for spills or leaks is negligible. All new process tanks and piping will be leak tested prior to use.

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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. All solid waste/debris generated during construction of the new structures and from demolition of existing structures will be disposed of off site in accordance with Minnesota solid waste regulations. Screenings and grit removed during the preliminary treatment processes will be transported to the nearest available landfill for disposal. As part of the treatment process, the proposed WWTF will produce sludge. Sludge will be dewatered and pasteurized using a heated lime stabilization process, to produce an Exceptional Quality (EQ) biosolids. The U.S. Environmental Protection Agency has developed guidelines for determining biosolids quality (40 Code of Federal Regulations, Part 503). Biosolids that meet the most stringent limits set for the presence of pollutants (arsenic cadmium, chromium, copper, lad, mercury, molybdenum, nickel, selenium, and zinc), the presence of pathogens (e.g., bacteria, viruses, parasites) and the biosolids attractiveness to vectors (e.g., rodents, flies) can qualify as EQ biosolids. Stabilized biosolids will be stored on site in an enclosed building with concrete floor for 180 days and then land applied to MPCA-approved agricultural land. This type of sludge treatment will be consistent with Minn. R. ch. 7041. The maximum projected sludge production rate is estimated to be 2,555 pounds/day in 2017. The City will continue to dispose of the sludge from the industrial treatment train at the Spruce Ridge Landfill. Three sludge lagoons, which once served as wastewater treatment ponds before the existing mechanical WWTF was constructed, are still in existence on site. The ponds also accepted sludge from the new mechanical WWTF before the existing biosolids processing system was constructed. The lagoons have not received wastewater or sludge since the biosolids processing system became operational in 1994. The existing NPDES/SDS Permit No. MN025666 contains a compliance schedule requiring the abandonment of these decommissioned lagoons. Abandonment will entail removing approximately 10.0 acres of water, which will be routed to the domestic treatment train at the Becker WWTF, and then dewatering and land applying the biosolids that have accumulated within the lagoons. The dikes for the ponds will be used to grade Lagoon 1 (Figure 3), which will be the site for the proposed domestic treatment train structures.

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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. There will be no toxic or hazardous materials used or present on site.

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. Aluminum sulfate hydrate (i.e., alum) and polymer to aid phosphorus removal is now, and will continue to be, stored on site. Alum is stored in two 4,000-gallon bulk tanks. The room walls are designed to provide spill containment, as the floor is located 3.5 feet below the door. Spills will be detected by a high level float alarm located in a sump in the floor of the storage room. Polymer is stored in 55-gallon drums in the same room. Polymer spills will be detected by the same high level float. The industrial (two tanks 124,000 gallons in size) and domestic (one tank 294,000 gallons in size) sludge storage tanks are constructed of bolted steel with concrete bottoms. They are designed to be leak proof according to American Water Works Association standard D103. Wastewater process tanks (existing and new) are constructed of concrete and follow the latest engineering practices to prevent leakage into the ground. Two generators will serve the Becker WWTF in times of power outages. There is an existing 1,000-gallon diesel fuel tank on site and a second 1,100-gallon diesel fuel tank will be added. The tanks will be double walled. A level switch is specified in the secondary containment tank of the new generator, and will alarm to the WWTF’s alarm system. The existing generator tank is also equipped with a similar alarm. WWTF staff is connected with a radio alarm and cell phone system 24 hours a day and 7 days a week to respond to any WWTF emergency.

21. Traffic. Parking spaces added: 8 Existing spaces (if project involves expansion): 6 Estimated total average daily traffic generated: 3-6 Estimated maximum peak hour traffic generated (if known) and its timing: Provide an estimate of the impact on traffic congestion affected roads and describe any traffic improvements necessary. If the project is within the

Twin Cities metropolitan area, discuss its impact on the regional transportation system. The project will add an additional eight parking spaces to the six spaces currently available. During the two-year construction period, there will be 5-10 construction trucks per day entering and leaving the project site during normal business hours. After the proposed project is operational, the City’s Water Department staff will be relocated to the WWTF. This may generate three to six additional vehicles entering and leaving the WWTF per day over current traffic levels. There is expected to be little to no impact on local traffic either during construction or after the project is completed.

22. Vehicle-related Air Emissions. Estimate the effect of the project’s traffic generation on air quality,

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including carbon monoxide levels. Discuss the effect of traffic improvements or other mitigation measures on air quality impacts. Note: If the project involves 500 or more parking spaces, consult EAW Guidelines about whether a detailed air quality analysis is needed. During construction, there will be some additional air emissions to the area from construction equipment, though there will be no significant increase in vehicle-related air emissions once the facility is operational. The only traffic to the site will continue to be the facility operators and other authorized personnel.

23. Stationary Source Air Emissions. Describe the type, sources, quantities and compositions of any emissions from stationary sources of air emissions such as boilers, exhaust stacks or fugitive dust sources. Include any hazardous air pollutants (consult EAW Guidelines for a listing), any greenhouse gases (such as carbon dioxide, methane, and nitrous oxides), and ozone-depleting chemicals (chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons or sulfur hexafluoride). Also describe any proposed pollution prevention techniques and proposed air pollution control devices. Describe the impacts on air quality. The WWTF will have two back-up, 600-kilowatt diesel generators to be used in times of electrical power outages. Air emissions from the emergency power generator will be infrequent and minor in nature.

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.) Normal levels of dust and noise is expected during construction. Dust will be controlled by daily cleanup of the construction site. Water will be used to wet the site and reduce the airborne dust, when necessary. Noise impacts from construction equipment will be minimized by restricting the hours of operation to that permitted in local ordinances. Long-term impacts on human health or quality of life are not expected. Odors can sometimes arise with the operation of wastewater treatment ponds; however, mechanical activated sludge treatment processes (such as the proposed WWTF) are aerated systems and normally do not cause odors. Odorous air from the existing packed towers and both the new domestic and existing industrial headworks buildings will be collected and treated in an on-site biofilter. The biofilter is designed to remove nuisance odors normally associated with wastewater treatment facilities. The new aeration basin and clarifiers are uncovered and they are not expected to generate nuisance odors.

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. According to a review of the State’s Historic and Archaeological Site Location database by the SHPO, no archaeological sites were identified in the proximity of the project. The project scope is limited to the City’s own properties and easements with no known existing archaeological sites. The existing Becker

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WWTF is adjacent to the City-owned baseball fields and a wooded river buffer. No impacts to the ball fields or wooded river buffer area are expected during the project. The SHPO’s letter is included as Attachment B.

26. Visual impacts. Will the project create adverse visual impacts during construction or operation? Such as glare from intense lights, lights visible in wilderness areas and large visible plumes from cooling towers or exhaust stacks? Yes No If yes, explain.

27. Compatibility with plans and land use regulations. Is the project subject to an adopted local comprehensive plan, land use plan or regulation, or other applicable land use, water, or resource management plan of a local, regional, state or federal agency? Yes No

If yes, describe the plan, discuss its compatibility with the project and explain how any conflicts will be resolved. If no, explain. The project appears to be compatible with the City’s Comprehensive Plan. It will be constructed on the City-owned WWTF property that is zoned for industrial use.

28. Impact on infrastructure and public services. Will new or expanded utilities, roads, other infrastructure or public services be required to serve the project? Yes No If yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is a connected action with respect to the project must be assessed in the EAW; see EAW Guidelines for details.) Potable water supply, electrical service, and an access road already exist at the site. No additional utilities, public roads or other infrastructure are needed to serve the project. The project does include replacement of an existing force main with a gravity sewer and elimination of the City’s existing lift station; however, this sewer improvement is not strictly required to serve the WWTF upgrade and expansion project.

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). The proposed WWTF is expected to serve the City for approximately ten years. The availability of municipal utilities will allow additional development within the City. Though the availability of expanded wastewater treatment capacity may encourage new development, this development will occur only if local economics support growth. For the past several years, the City has not accepted new plats, so there are no platted and approved development projects that will be served by the proposed project. Development projects in progress now can be served by the City’s existing wastewater treatment

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Becker WWTF Location

Figure 1 Location of Becker WWTF in Sherburne CountyA

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Figure -3 Overall Site Plan
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WWTF ExpansionProject Location

ExistingWastewater Pond 1

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PEMC - Palustrine Emergent Seaonsally Flooded Shallow Marsh

PSS1C - Palustrine Scrub Shrub Seaonslly Flooded Basin

Figure 5Becker WWTF ExpansionUSGS Topo MapNWI Overlay

NWI Classification KeyPUBKx - Palustrine Unconsolidated Bottom Artifically Flooded Excavated

PFO1C - Palustrine Forested Seasonally Flooded Wooded Swamp

WWTF ExpansionProject Location

ExistingWastewater Pond 1

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SSWD - Dark, Well Drained Sandy Soil

AAAA - Alluvial Soils

Figure 6Becker WWTF ExpansionUSGS Topo MapSoil Classification Overlay

Soil Classification Key