RE: St. Michael Wastewater Treatment Facility (WWTF) Expansion

Transcription

1 February 4, 2000 TO INTERESTED PARTIES: RE: St. Michael Wastewater Treatment Facility (WWTF) Expansion Enclosed is the Environmental Assessment Worksheet (EAW) for the proposed St. Michael WWTF Expansion, Wright County. The EAW was prepared by the Minnesota Pollution Control Agency (MPCA) and is being distributed for a 30-day review and comment period pursuant to the Environmental Quality Board (EQB) rules. The comment period will begin the day the EAW availability notice is published in the EQB Monitor, which will likely occur in the February 7, 1999, issue. Please note that Figures 2, 4 and 5 are not included in this packet, but will be mailed as soon as they are available. I apologize for any inconvenience. Comments received on the EAW will be used by the MPCA in evaluating the potential for significant environmental effects from this project and deciding on the need for an Environmental Impact Statement (EIS). A final decision on the need for an EIS will be made by the MPCA Commissioner after the end of the comment period. If a request for an EIS is received during the comment period, or if the Commissioner recommends the preparation of an EIS, the nine-member MPCA Citizens Board (Board) will make the final decision. The final EIS need decision will also be made by the Board if so requested by the project proposer, other interested parties or MPCA staff and if this request is agreed to by one or more members of the Board or the MPCA Commissioner. The Board meets once a month, usually the fourth Tuesday of each month, at the MPCA office in St. Paul. Meetings are open to the public and interested persons may offer testimony on Board agenda items. A listing of Board members is available on request by calling (651) Please note that comment letters submitted to the MPCA do become public documents and will be part of the official public record for this project. If you have any questions on the EAW, please contact Eric Kilberg of my staff at (651) Sincerely, Joseph L. Esker District Planning Supervisor Operations and Planning Section Metro District JLE:sjs Enclosure

2 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 RGU, to determine whether an 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 warrant further investigation, and the need for an EIS. A copy of the EAW may be obtained from the MPCA. An electronic version of the EAW is available at the MPCA website 1. Project Title: St. Michael Wastewater Treatment Facility (WWTF) Expansion 2. Proposer: City of St. Michael 3. RGU: Minnesota Pollution Control Agency Contact Person Robert Derus Contact Person Eric Kilberg and Title City Administrator and Title Project Manager Address P.O. Box 337 Address 520 Lafayette Road North St. Michael, MN St. Paul, Minnesota Phone Phone Fax Fax Reason for EAW Preparation: EIS Scoping X Mandatory EAW Citizen Petition RGU Discretion Proposer Volunteered If EAW or EIS is mandatory give EQB rule category subpart number subp. 18B and subpart name Wastewater systems For expansion or reconstruction of an existing municipal or domestic wastewater treatment facility which results in an increase by 50 percent or more and by at least 50,000 gallons per day of its average wet weather design flow capacity, or construction of a new municipal or domestic wastewater treatment facility with an average wet weather design flow capacity of 50,000 gallons per day or more, the MPCA shall be the RGU. 5. Project Location: County Wright City/Twp St. Michael NW 1/4 SE 1/4 Section 13 Township 120 N Range 24 W Attach each of the following to the EAW: State map showing the location of St. Michael (Figure #1); County map showing the general location of the project (Figure #2); United States Geological Survey 7.5 minute, 1:24,000 scale map indicating project boundaries (Figure 3); and Site plan showing all significant project and natural features (Figures 4 and 5). TDD (for hearing and speech impaired only): (651) Printed on recycled paper containing at least 10% fibers from paper recycled by consumers

3 6. Description: a. Provide a project summary of 50 words or less to be published in the EQB Monitor. The city of St. Michael (City), in Wright County, proposes an expansion of its existing Wastewater Treatment Facility (WWTF) from the existing design flow capacity of to million gallons per day. The proposed work includes improvements to existing unit processes and construction of a new sequencing batch reactor secondary treatment unit process. Tertiary treatment for phosphorus removal is proposed to meet an annual average effluent limit of 1 milligram per liter (mg/l). The facility will also meet an effluent biochemical oxygen demand limit of 15 mg/l. The facility will discharge to the Crow River. b. Give a complete description of the proposed project and related new construction. Attach additional sheets as necessary. Emphasize construction, operation methods and features that will cause physical manipulation of the environment or will produce wastes. Include modifications to existing equipment or industrial processes and significant demolition, removal or remodeling of existing structures. Indicate the timing and duration of construction activities. The proposed project will supplement the existing system, which consists in part of a Biolac secondary treatment process. The headworks of the plant will be modified by the addition of a duplex wet-weather pumping station to supplement the capacity of the existing lift station. The existing bar screen will be used. A splitter box will apportion flow between the Biolac system and the new secondary treatment process. The new secondary treatment will consist of two 1.25 million gallon concrete sequencing batch reactor (SBR) cells. An SBR is a type of wastewater treatment system that provides a single, complete-mix reactor in which all treatment steps typical of an activated sludge treatment process occur. Separate cycle times are used to fill, react, settle solids and decant liquids. Since SBR is a batch rather than a continuous process, it will typically require a downstream surge tank for flow equalization. This project therefore includes the construction of a 300,000-gallon concrete surge tank. In the SBR process, anaerobic and anoxic mixing periods are provided by modifying the cycle time and controlling the air supply. Anaerobic (where oxygen in any form is totally absent from the solution) conditions favor the growth of bacteria that consume phosphorus. Anoxic conditions (where oxygen is present as nitrate NO 3 ) favor the growth of organisms that convert nitrate to nitrogen and oxygen, and that absorb phosphorus. Manipulating the SBR process by controlling the oxygen content allows the plant operator to maximize the removal of phosphorus and ammonia without the addition of chemicals. The proposed SBR would remove 95% of CBOD 5 and TSS, 96% of the ammonia, and 60% of the phosphorus in the influent wastewater. The Biolac system would remove 90% of the CBOD 5 and TSS, 100% of the ammonia, and 40% of the phosphorus. Additional removal will be accomplished through the addition of aluminum sulfate (alum), ferric chloride, or ferric sulfate to the surge tank. The effluent will be pumped to a conventional 75-foot diameter clarifier, covered to prevent freezing. Biosolids (sludges) treatment will be upgraded by the addition of one 450,000-gallon sludge tank and four 40-foot by 95-foot reed bed cells during this phase of construction. Aerobic digestion of the sludge will take place in the storage tank, and the stored sludge will be pumped onto the reed beds. In addition, the existing Ultraviolet (UV) disinfection system will be upgraded to enable disinfection of the increased flows. 2

4 There will be no demolition. The City intends to begin construction activities as soon as it is granted a National Pollution Discharge Elimination System (NPDES) Permit, perhaps as early as April 2000, with completion scheduled for June 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 increase in design flow is necessary to provide treatment to the expanded service area of the St. Michael WWTF. The potential service area has expanded since the 1995 Facilities Plan for the following reasons: 1. The City annexed the former Township of Frankfort in 1996 and has extended sewer service to some parts with plans to service additional areas. This area is expected to be the source of about 90% of the projected increase in population served by the St. Michael WWTF. Substantial commercial and industrial development is anticipated as well. 2. The City has reached an agreement with the city of Hanover to extend sewer service to Hanover. The 20-year design population of Hanover is 2,370 people. 3. The City is currently negotiating with the Township of Rockford to extend sewer service to a residential area with failing septic systems. The 20-year design population of Rockford Township is 555 people. The graph below shows the projected growth rates within the service area. The City of St. Michael represents the single most significant contributor to increases in population within the service area. 30,000 Population 25,000 20,000 15,000 10,000 City of St. Michael Hanover Rockford Total Service Population St. Michael (unsewered) 5,

5 The beneficiaries of the project are the current and future residents of the City, as well as current and future commercial and industrial users located in the City. The construction will enable the construction of residential, commercial, and light industrial developments on land that is currently agricultural or open space. As such, the project will financially benefit the owners of that land and those interests that will undertake its development. 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. Based on population projections prepared by the City Planner, the WWTF will need to be upgraded in 10 years from million gallons per day (mgd) to mgd. The project is being constructed to provide wastewater collection and treatment to land that is presently undeveloped. This will enable the residential and commercial development of that land, located in St. Michael, Hanover, and part of Rockford. 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. An EAW was prepared during Facilities Planning for the existing WWTF in Project Magnitude Data Total Project Area (acres) 16 acres or Length (miles) Number of Residential Units: Unattached NA Attached NA maximum units per building NA Commercial/Industrial/Institutional Building Area (gross floor space): total square feet 4000 Indicate area of specific uses (in square feet): Office Manufacturing Retail Other Industrial Warehouse Institutional Light Industrial Agricultural Other Commercial (specify) Building height 24 If over 2 stories, compare to heights of nearby buildings 4

6 8. Permits and approvals required. List all known local, state and federal permits, approvals and financial assistance for the project. Include modifications of any existing permits, governmental review of plans, and all direct and indirect forms of public financial assistance including bond guarantees, Tax Increment Financing and infrastructure. Unit of Government Type of Application Status MPCA Facility Plan Preliminary approval granted MPCA NPDES Permit (for wastewater Application submitted discharge) MPCA NPDES Permit (stormwater discharge) Will be applied for by contractor during Minnesota Department of Natural Resources (MDNR) MDNR Temporary Water Appropriation Permit for Construction Dewatering. Work in the beds of public construction Will be applied for by contractor during construction Will be applied for during construction. waters permit City Building Permit Will be applied for during construction. City Storm Water Will be applied for during construction. 9. Land use. Describe current and recent past land use and development on the site and on adjacent lands. Discuss project compatibility with adjacent and nearby land uses. Indicate whether any potential conflicts involve environmental matters. Identify any potential environmental hazards due to past site uses, such as soil contamination or abandoned storage tanks, or proximity to nearby hazardous liquid or gas pipelines. The site is adjacent to the existing WWTF. Adjacent areas are used as city parks, existing mechanical wastewater treatment, former wastewater treatment stabilization ponds (to be abandoned as a part of this project), and low-density residential development. The residential development of about 100 homes is located approximately 400 feet from the proposed new construction. 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 2 Wooded/forest Impervious Surfaces 1 Brush/grassland Other (describe) *WWT Ponds 8 Cropland *Aeration Basins and Reed Beds 1.5 TOTAL Fish, Wildlife, and Ecologically Sensitive Resources a. Identify fish and wildlife resources and habitats on or near the site and describe how they would be affected by the project. Describe any measures to be taken to minimize or avoid impacts. The Crow River is classified as a 2B water of the State. The proposed WWTF will discharge continuously to the Crow River, meeting discharge standards assigned by the MPCA. If allowed to discharge at the normal CBOD 5 discharge limit of 25 mg/l, the cumulative effect of all of the 5

7 WWTF s discharging to the Crow River would have the potential to cause dissolved oxygen (DO) depletions below the applicable water quality standard of 5 mg/l. For this reason, the St. Michael WWTF will be capable of meeting a CBOD 5 limit of 15 mg/l and an NH 3 limit of 3 mg/l in the summer and 5 mg/l in the winter. The land to be used for the proposed upgrade is mowed grassland, so wildlife resources are not expected to be significantly impacted by construction of this facility. Since the project will enable the development of a significant portion of the City, it will result inevitably in the conversion of land that is largely agricultural to suburbanized land use. This conversion will result in a reduction in the species diversity, a reduction in the populations of individual species, and a conversion of types of resident species to those that are more tolerant of humans. Some species will be extirpated from the area as their ideal habitat is eliminated. 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: ES Describe measures to minimize or avoid adverse impacts. The Minnesota Natural Heritage database has been reviewed to determine if any rare plant or animal species or other significant natural features are known to occur within an approximate one-mile radius of the area indicated on the map enclosed with your information request. Based on this review, there are 6 known occurrences of rare species or natural communities in the area searched (for details, see enclosed database printout and explanation of selected fields). However, based on the nature and location of the proposed project I do not believe it will affect any known occurrences of rare features. 12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration dredging, filling, stream diversion, outfall structure, diking, and impoundment of any surface waters such as a lake, pond, wetland, stream or drainage ditch? Yes No If yes, identify water resource affected. Describe alternatives considered and proposed mitigation measures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the water resources affected are on the PWI. The existing wastewater facility discharges final effluent to the existing wastewater treatment ponds that are no longer used for treatment purposes. The flow meanders through the ponds to the Crow River. This has created a habitat, which has been observed to attract numerous waterfowl. The MPCA has determined that the ponds should be either dredged or dewatered. The expense of dredging the ponds would be prohibitive. The City will dewater the entire pond area and remove all sludge. Part of the pond area will be filled. A new outfall to the Crow River will be constructed. The filled pond area will be graded and reserved for future municipal uses such as parkland, and/or future wastewater treatment plant expansions. The sludge removed will be tested to see that it meets Environmental Protection Agency (EPA) Exceptional Quality Biosolids criteria and be spread on the created uplands. The pond area which is not filled will be used for storm water detention ponds and/or constructed wetlands. 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)? 6

8 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 MDNR 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. Construction of the WWTF will require a MDNR general permit for Temporary Water Appropriation. This permit is for dewatering activities associated with construction. The general contractor will be responsible for obtaining the permit. Dewatering will likely be necessary for construction of the outfall line in the area near the Crow River. Dewatering is not expected to have a long-term impact on groundwater levels. Construction of the concrete basins and storage tanks associated with the project will require testing for water tightness. This will require a total of 3 to 5 million gallons of water. This water will likely be treated wastewater; however, it may be necessary to use some municipal water if there are not sufficient quantities of wastewater. The contractor will be responsible for purchasing this water from the Joint Powers Water Board if necessary. 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 outfall structure for the WWTF will be located within the 100-year flood plain of the Crow River. The final effluent discharge monitoring station is located 16 feet above the 100-year flood plain; therefore, no adverse affects will be experienced in the WWTF in the event of a 100-year flood. St. Michael has a Shoreland Ordinance that is based on the MDNR model ordinance, which restricts development within 1000 feet of surface water. The construction of the outfall structure is a conforming use under that ordinance. 15. Water Surface Use. Will the project change the number or type of watercraft on any water body? Yes No If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding or conflicts with other uses. 16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: 16 acres; 30,000 cubic yards. Describe any steep slopes or highly erodible soils and and identify them on the site map. Describe any erosion and sedimentation control measures to be used during and after project construction. Soils investigations of the area were done in February 1991 and January 1995 for construction of the abandoned rapid infiltration basins and 1995 WWTF Upgrade respectively. The soil boring logs describe primarily silty sand, silty clayey sand and sand. Additional soil borings will be taken at the locations of new structures. All excavated materials will be balanced on site. (Material excavated for construction of buildings and concrete tankage will be used as fill in the stabilization ponds to be abandoned). The construction will be conducted in accordance with the requirements of the NPDES General Stormwater Construction Permit. All disturbed areas will be protected from erosion with the use of silt fence and hay bales and other means as necessary. Silt fence will be placed at the perimeter of the 7

9 disturbed areas where the ground slopes to surface water or off site. As soon as possible after construction is complete, areas intended to remain unpaved will be seeded. 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 quantity of runoff from the WWTF will be unchanged. The site currently drains to the abandoned stabilization ponds. The section of the abandoned ponds which is not to be filled will be used as a storm water retention basin. This basin will be designed for runoff from future development in this area in addition to the current project. Silt fences, hay bales and prompt revegetation will be used to manage runoff per the requirements of the NPDES General Storm Water Permit. 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. Runoff from the facility will be collected and discharged to a storm water pond located at the WWTF site. The storm water pond will discharge to the Crow River. One of the purposes of this project is to serve new development in the St. Michael and Hanover areas. New development in these areas will result in a general increase in impervious surfaces that will cause increases in storm water runoff. Increased runoff can potentially cause flooding, erosion, entrainment of nutrients and sediments, sedimentation, and water pollution by sediments, nutrients, and thermal effects. It is therefore necessary that the increased development be controlled in a way that prevents these adverse impacts. The city of St. Michael is in the process of adopting a new ordinance regulating storm water discharge from new development. The new ordinance is modeled after the MPCA s recommended storm water ordinance. The city of Hanover is also developing a storm water plan. 18. Water Quality: wastewaters a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewater produced or treated at the site. 8

10 The WWTF will be designed to treat wastewater from St. Michael, Hanover and portions of Rockford Township. St. Michael and Hanover have a typical mix of residential, commercial and light industrial development. Neither community has any significant contributing industries as defined by the MPCA. The wastewater in St. Michael is characteristic of normal domestic wastewater. The average influent concentration of permit parameters at the design flow are expected to be: CBOD 5 Total Suspended Solids (TSS) Total Phosphorus (TP) Total Kjeldahl Nitrogen 208 mg/l 245 mg/l 9.8 mg/l 30 mg/l The wastewater design flow rates for the design year of 2010 are as follows: Average Dry Weather Average Wet Weather (design flow) Peak Hourly Wet Weather Peak Instantaneous Wet Weather mgd mgd 6.4 mgd mgd 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 following new processes will be constructed: a. One duplex wet-weather pumping station. b. Two 1.25 million gallon concrete SBR cells. c. One 300,000-gallon concrete surge tank. d. One 75-foot diameter tertiary treatment clarifier. e. One control building housing aeration blowers, chemical feed equipment and controls. f. One sludge pumping station. g. One 450,000-gallon sludge storage tank. h. Four 40-foot by 95-foot reed bed cells. In addition, the existing UV disinfection system will be upgraded to the new capacity. The upgraded WWTF will be capable of meeting more restrictive discharge limits for CBOD 5 and total suspended solids of 15 mg/l and 30 mg/l, respectively. The upgraded facility will also be capable of meeting a 1 mg/l total phosphorus limit and a 3 mg/l summer and 5 mg/l winter ammonia limit. The treated effluent will be discharged to the Crow River. The Crow River flows into the Mississippi River. The City does not currently have phosphorus or ammonia discharge limits. Construction of the new facility will reduce the discharge concentration of these two parameters as well as the concentration of CBOD 5. These effluent limits were set by the MPCA in order to protect the water quality in the river. 9

11 Pursuant to Minn. R. Ch , the Crow River is assigned a 2B, 3B, 4A, 4B, 5 and 6 use classifications. The quality of a 2B water should permit the propagation and maintenance of a healthy community of cool or warm water sport or commercial fish and their related habitat. Such a water should also be safe for direct body contact. The water quality standards that apply to the Use Classifications are: a DO level not less than 5.0 mg/l; an un-ionized ammonia level not greater than 40 μg/l; and a fecal coliform level not to exceed 200 organisms per 100 ml of effluent. The effluent limits that will be included in the NPDES permit are: 15 mg/l CBOD 5; 30 mg/l TSS; 6 mg/l DO; 3 mg/l ammonia (summer) and 5 mg/l ammonia (winter); 200 Organisms/100 ml fecal coliform; and 1 mg/l TP (annual average). These effluent limits are protective of the water quality standards and the water quality use classifications that they support. The Crow River receives treated wastewater from numerous municipalities in its watershed. The heavy use of the river for this purpose has resulted in the imposition of effluent limits on dischargers that are more restrictive that those applied to typical Minnesota cities that discharge to other rivers. In particular, it is not unusual to see more restrictive limits on CBOD 5 to protect the ambient DO standard. In the case of St. Michael, the City has received more restrictive effluent limits for CBOD 5, ammonia, and DO, to protect the dissolved oxygen water quality standard. Since the Crow River discharges ultimately to the Mississippi, incremental increases in wastewater associated nutrients cumulatively impact the water quality of that river and ultimately of the Gulf of Mexico. Increasingly, phosphorus is a nutrient of concern. Particularly in the Crow River basin, cities have been required, or have voluntarily accepted, effluent phosphorus limits of 1 mg/l. St. Michael has proposed biological phosphorus treatment that will achieve that effluent limit, and a tertiary clarification system that could achieve even better removal if necessary. 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. 10

12 The city of St. Michael adopted a pretreatment ordinance in The city of Hanover adopted a pretreatment ordinance in Both ordinances restrict discharges to municipal sewers to domestic strength wastewater meeting the following limits: CBOD mg/l TSS 250 mg/l ph mg/l Fats, Oils and Grease 100 mg/l Metals as determined by the WWTF operator 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. The project does not require disposal of animal manure. 19. Geologic hazards and soil conditions a. Approximate depth (in feet) to ground water: 20 feet minimum; 31 feet average. bedrock: >40 feet minimum; >40 feet 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. None of these hazards are known to exist. b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity and potential for groundwater contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. Soils with the following Soil Conservation Service (SCS) classifications can be identified at the project site: Symbol Classification Percolation Rate Soil Capability Unit EtA Estherville Sandy Loam 0.6 to 6.3+ /hr IIIs-2 EtC2 Estherville Loam 0.6 to 6.3+ /hr IVe-3 EtD Estherville Sandy Loam 0.6 to 6.3+ /hr VIe-2 HsB Hubbard Loamy Sand 1.0 to 6.3+ /hr IVs-2 SaE Salida Gravelly Sandy Loam 1.0 to 6.3+ /hr VIIs-2 Source: United States Department of Agriculture, SCS, Soil Survey, Wright County (1968). Gravity sewer will be constructed of Polyvinyl Chloride (PVC) meeting American Society for Testing Materials (ASTM) 3034 standards. Force main will be constructed of PVC meeting American Waterworks Association C-900 or Polyethylene meeting ASTM D3350 or ASTM F714. All gravity sewer and force main piping will be pressure tested following installation and before placement into service to verify water tightness. 11

13 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. The WWTF will generate sludge as a byproduct of wastewater treatment. The treatment and disposal of these materials is regulated by the EPA Part 503 rule. That rule categorizes sludge as Class A or Class B based on the quality. The quality of the sludge determines acceptable disposal practices. St. Michael employs an innovative sludge treatment and storage process known as Reed Beds. Sludge generated in the secondary and tertiary treatment processes will be stored in aerated sludge storage tanks. Periodically, the sludge will be discharged from the sludge storage tanks to the Reed Beds. Sludge will be stored on the reed beds for 7 to 10 years. When the sludge accumulates to a total depth of 42, the Reed Beds will be evacuated. The evacuated sludge is expected to meet criteria for EQ biosolids. This will have to be determined at the time of evacuation through pathogen and metals testing. The evacuated sludge will be land applied. If the sludge meets EQ criteria, there will be no restrictions on disposal. If the sludge does not meet EQ criteria, it will meet Pollutant Concentration criteria. This option would require bulk disposal on permitted land application sites. b. Identify any toxic or hazardous materials to be used or present at the site and identify measures to be used to prevent them from contaminating groundwater. If the use of toxic or hazardous materials will lead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize or eliminate the waste, discharge or emission. In order to meet the 1 mg/l Total Phosphorus discharge limit, the WWTF will have to add phosphorus removal chemicals to supplement biological phosphorus removal. The chemicals used will be alum, ferric chloride or ferric sulfate. A storage tank with a capacity of 6500 gallons will be housed in the control building inside a secondary containment area. Any above-ground tank with a capacity greater than 500 gallons that is within 500 feet of a Class 2 water is regulated by Minn. R. Ch 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. Sludge will be stored in a 450,000 gallon buried concrete storage tank. The tank will be covered. Minn. R , subp. 2a, specifically exempts wastewater structures and tanks from regulation as an above-ground tank, since it is already regulated under the NPDES program. Fuel storage for the emergency power generators is provided in an existing double-walled 240 gallon tank that is part of the emergency generator. The tank is not regulated since it does not have a sufficiently large capacity to be subject to Minn. R. Ch (See Item 20b, above.) 21. Traffic. Parking spaces added 6 Existing spaces (if project involves expansion) 6 Estimated total average daily traffic generated 12 Estimated maximum peak hour traffic generated (if known) and its timing: N/A Provide an estimate of the impact on traffic congestion affected roads and describe any traffic improvements necessary. If the project is within the Twin Cities metropolitan area, discuss its impact on the regional transportation system. This facility is not expected to significantly impact traffic locally or regionally. Residential development enabled by the construction of additional wastewater treatment capacity will, however, result in noticeable impacts. 12

14 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. Vehicle emissions associated with the facility will not have a significant effect on air quality. However, residential development enabled by the construction of additional wastewater treatment capacity may result in measurable but not significant impacts. If traffic increases result locally in future deterioration in levels of service, and /or air quality violations, there are mitigative measures mainly roadway improvements and signal installation available. 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. There are only two stationary sources of air pollution associated with the project. The first is natural gas heating in the building. This unregulated stationary source will have minimal effect on air quality. The second is the emergency generator for the facility. This is also unregulated, and will have minimal impact on air quality. 24. Odors, noise and dust. Will the project generate odors, noise or dust during construction or during operation? Yes No If yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures to mitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts on them. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated by operations may be discussed at item 23 instead of here.) Dust will be generated as a result of construction. Construction equipment will generate noise and exhaust odors. Construction will be limited to the hours between 7:00 am and 7:00 p.m. Monday through Saturday. The project will begin construction in April 2000 with substantial completion scheduled for June All odor causing unit processes will be controlled. The influent pumping station will be covered. The bar screen room is enclosed. Aeration tanks include installed backup aeration equipment to prevent septic conditions from developing. Sludge storage tanks will be covered. There are some residences as close as 400 feet from the project site. The existing plant has operated for over three years with no odor complaints. 13

15 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. a) There is an existing recorded archaeological property near the WWTF. Between 1991 and 1996, this property was surrounded by a rapid infiltration basin used to dispose of wastewater from the old stabilization ponds. The 1995 upgrade to the WWTF allowed use of the rapid infiltration basins to be discontinued. The 2000 upgrade will have no impact on the archeological site. The State Historic Preservation Office has been contacted and has indicated that they will comment on the project during their review of the EAW. b) Construction of the WWTF will not have a direct impact on prime farmlands; however, future development will invariably result in conversion of some prime farmland (Type I and II) to residential and commercial uses. St. Michael s Comprehensive Plan calls for concentration of development in the eastern portion of the city. It is anticipated for the next twenty years that the western portion of St. Michael will remain in agricultural land use. c) The WWTF is located across the Crow River from the Crow-Hassan County Park. The City maintains three athletic fields to the west of the WWTF. A BMX bike racing track is located southwest of the WWTF. A Biking trail is located northwest of the WWTF. It is not expected that the facility will have any impact, other than visual, on these facilities. This project will include filling part of the old stabilization ponds, creating more uplands for public use. Public uses may include parks and walking trails. 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 complies with the 1997 St. Michael Comprehensive Land Use Plan, adopted in January of 1998, and with the 1999 Lander Avenue and Meadow Pond Land Use Plan (Appendix to the 1997 city of St. Michael Comprehensive Plan. St. Michael s Comprehensive Plan has been included as a case study of smart growth planning in a report entitled Two Roads Diverge, prepared by the Center for Energy and Environment, Minnesotans for an Energy-efficient Economy, and 1000 Friend of Minnesota. The plan calls for staging development so that occurs in the eastern part of the city first. The western part of the city, which is primarily agricultural, will be provided only with limited sewer service where 14

16 concentrations of failing on-site systems are found around lakes. In the western part of the City, zoning controls restrict development to 1 dwelling per 40 acres. Accordingly, the development that occurs in the City in the foreseeable future should be channeled away from agricultural land. 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.) Impacts on infrastructure by the proposed project per se are not expected to be significant. The increase in capacity at the WWTF is intended to enable new development in the service area. As a result of this increased development, there will be increased pressures on infrastructure such as streets and roads, municipal water and sewer lines, natural gas, electricity, and telephone and cable services, schools, fire and police protection, emergency medical services, and stormwater collection and treatment. Increased commuting has already resulted in demands for major highway construction. 29. Cumulative impacts. Minn. R , subp. 7, item B requires that the RGU consider the cumulative potential effects of related or anticipated future projects when determining the need for an environmental impact statement. Identify any past, present or reasonably foreseeable future projects that may interact with the project described in this EAW in such a way as to cause cumulative impacts. Describe the nature of the cumulative impacts and summarize any other available information relevant to determining whether there is potential for significant environmental effects due to cumulative impacts (or discuss each cumulative impact under appropriate item(s) elsewhere on this form). All cumulative impacts are discussed under the appropriate items elsewhere on this form. 30. Other Potential Environmental Impacts. If the project may cause any adverse environmental impacts not addressed by items 1 to 28, identify and discuss them here, along with any proposed mitigation. None identified. 31. Summary of issues. Do not complete this section if the EAW is being done for EIS scoping; instead, address relevant issues in the draft Scoping Decision document, which must accompany the EAW. List any impacts and issues identified above that may require further investigation before the project is begun. Discuss any alternatives or mitigative measures that have been or may be considered for these impacts and issues, including those that have been or may be ordered as permit conditions. Item 11a. Fish, Wildlife and Ecologically Sensitive Resources. The proposed facility will treat wastewater and release an effluent that will protect the water quality and water use classifications in the receiving water, the Crow River. Actual construction on site is expected to have no impact on area wildlife. However, development enabled by the project will convert land from agricultural and open space to suburban developments. This land use conversion will cause changes in species types and numbers, as existing species are replaced by those more tolerant of humans. Item 17b. Water Quality - Surface Water Runoff. New development in areas served by the plant will result in a general increase in impervious surfaces that will cause increases in storm water runoff. Increased runoff can potentially cause flooding, erosion, entrainment of nutrients and sediments, sedimentation, and water pollution by sediments, nutrients, and thermal effects. It is therefore necessary that the increased development by controlled in a way that prevents these adverse impacts. The city of St. 15

17 Michael has adopted a new ordinance regulating storm water discharge from new development. The new ordinance is modeled after the MPCA s recommended storm water ordinance. Hanover is in the process of developing storm water management plans. Item 18. Water Quality - Wastewaters. The cumulative effect of numerous WWTFs along the Crow River has the potential to cause DO depletion below the applicable water quality standard of 5 mg/l. The St. Michael WWTF will be capable of meeting a CBOD 5 limit of 15 mg/l and an NH 3 limit of 3 mg/l in the summer and 5 mg/l in the winter, in order to protect this water quality standard. Similarly, incremental discharges of wastewater to the Mississippi cumulatively impact the water quality of that river and ultimately of the Gulf of Mexico. Particularly in the Crow River basin, cities have been required, or have voluntarily accepted, effluent phosphorus limits of 1 mg/l. St. Michael has proposed biological phosphorus treatment (Bio-P) that will achieve that effluent limit, and a tertiary clarification system that could achieve even better removal if required. Item 22. Vehicle-related Air Emissions. Vehicle emissions associated with the facility will not have a significant effect on air quality. However, residential development enabled by the construction of additional wastewater treatment capacity may result in measurable but not significant impacts. If traffic increases result locally in deterioration in levels of service, and /or air quality violations mitigative measures are available. Item 25a. Archaeological Resources. There is an existing recorded archaeological property near the wastewater treatment facility. The State Historic Preservation Office has been contacted but has not yet commented on the project. Item 25b. Prime Farmland. Construction of the WWTF will not have a direct impact on prime farmlands. Enabled development will result in conversion of some prime farmland to residential and commercial uses. St. Michael s Comprehensive Plan calls for concentration of development in the eastern portion of the City. It is anticipated for the next twenty years that the western portion of St. Michael will remain in agricultural land use. Item 28. Impact on infrastructure and public services. The increase in capacity at the WWTF is intended to enable new development in the service area. As a result of this increased development, there will be increased pressures on infrastructure such as streets, municipal water and sewer lines, natural gas, electricity, and telephone and cable services, schools, fire and police protection, emergency medical services, stormwater collection and treatment and major arterial roads and highways. 16

18 RGU CERTIFICATION. The Environmental Quality Board will only accept SIGNED Environmental Assessment Worksheets for public notice in the EQB Monitor. I hereby certify that: The information contained in this document is accurate and complete to the best of my knowledge. The EAW describes the complete project; there are no other projects, stages or components other than those described in this document, which are related to the project as connected actions or phased actions, as defined at Minn. R , subps. 9b and 60, respectively. Copies of this EAW are being sent to the entire EQB distribution list. Name and Title of Signer: Joseph L. Esker, District Planning Supervisor Operations and Planning Section, Metro District Date: Environmental Assessment Worksheet was prepared by the staff of the Environmental Quality Board at Minnesota Planning. For additional information, worksheets or for EAW Guidelines, contact: Environmental Quality Board, 658 Cedar St., St. Paul, MN 55155, , or 17