STATE OF MINNESOTA MINNESOTA POLLUTION CONTROL AGENCY

Transcription

1 STATE OF MINNESOTA MINNESOTA POLLUTION CONTROL AGENCY In the Matter of the Decision on the Need for an Environmental Impact Statement for the Proposed Remer Wastewater Treatment Facility Expansion FINDINGS OF FACT AND CONCLUSIONS The city of Remer (City) is proposing to reconstruct and expand its wastewater treatment facility (WWTF). Pursuant to Minn. R , subp. 18.B., the Minnesota Pollution Control Agency (MPCA) staff has prepared an Environmental Assessment Worksheet (EAW) for the project. Based on the EAW and comments or information received during the EAW comment period, the MPCA hereby makes the following. PROJECT DESCRIPTION FINDINGS OF FACT 1. Project Proposal. The City (population 345) is proposing to upgrade its wastewater collection and treatment system to alleviate deficiencies in the current system. The upgrades include repairing and expanding the collection system (including the installation of one new lift station and replacing two that are malfunctioning), constructing an additional 9.67-acre treatment pond on a 12-acre site, and replacing the force-main between the treatment ponds and the new lift station. Upon completion, the proposed pond will become the primary pond to which all of the City s wastewater will be diverted for primary treatment. The existing treatment ponds will then become secondary treatment ponds. Upon completion, the total wastewater treatment system (stabilization ponds) will comprise 17.6 acres, with a total operating volume of million gallons. This will provide a total detention time of 215 days based upon a 106,300 gallons per day (gpd) flow. TDD (for hearing and speech impaired only): (651) Printed on recycled paper containing at least 100% fibers from paper recycled by consumers

2 2. Existing System. The current system consists of a collection system and stabilization ponds that discharge treated effluent into the Willow River during spring and fall, as permitted in an MPCA National Pollutant Discharge Elimination Systems (NPDES) permit. The two existing stabilization ponds include: a primary treatment pond, 5.2 acres in size with a capacity of 6.78 million gallons, and a secondary treatment pond, 2.7 acres in size with a capacity of 3.52 million gallons. They are located southeast of the City. The ponds were sized based on a design flow of 55,000 gpd and a total detention time of 180 days. A 1997 evaluation concluded that the existing system is inadequate: a) the stabilization ponds are undersized; b) many pipes in the collection system are too shallow and subject to periodic freezing (creating a need to leave faucets running to mitigate the problem which, in turn, adds unnecessary inflow to the treatment ponds); c) other pipes need to be replaced as they are allowing ground water to infiltrate into the system; d) serious problems exist with the two lift stations (one of which is not functioning at all); and e) force-mains are in need of repair. In addition, residences located in the south and west part of the City are not currently connected to the municipal treatment system, and many of the existing individual sewage treatment systems (ISTSs) in these areas are known to be failing and out of compliance with applicable requirements

3 3. Project Site. The repairs and extension of the collection system will be made within the City. The City is a small residential community located in north central Minnesota, situated in the southeastern corner of the Chippewa National Forest. The additional treatment pond will be built within a 12-acre parcel of farmland, located directly north and adjacent to the existing ponds, on property that the City is in the process of purchasing. While the geography around the City predominately consists of forests in varied terrain intermixed with water features, lakes, streams, and wetlands, the parcel of land where the proposed pond will be built is currently used for agricultural purposes (grazing). This land parcel is outside of the City s incorporated area. 4. Major Elements. The proposed project consists of the following planned improvements: a) construct a properly-designed collection system for the unsewered areas of the City and repair and/or replace deficient components of the existing collection system (including installing three new lift stations); b) replace the force-main between one of the faulty lift stations and the treatment ponds; and c) expand the existing treatment pond system. With the exception of the treatment pond expansion, the improvements will be done in existing right-of-ways and easement areas. An estimated 50 new connections will be added to the wastewater collection system as a result of the extension of the collection system. 5. The additional 9.67-acre pond will have a million-gallon capacity and will be constructed with a synthetic liner. Select granular borrow will be used above and below the lining for protection. To prevent erosion, the inside of the pond dikes will have at least a nine inch layer of riprap extending from the toe of the dike to one foot above the six foot water level. The proposal is designed to meet the City s wastewater treatment needs for a 20-year time frame. 6. Treated wastewater will be released from the ponds to the Willow River in accordance with the NPDES permit requirements. The existing, sufficiently sized, gravity flow outfall line will be used to allow the discharge of up to six inches of water from the ponds each day during the discharge period. PROJECT HISTORY 7. The project involves the expansion of a municipal WWTF, which will result in an increase of more than 50 percent of its Average Wet Weather (AWW) design flow. The preparation of an EAW is mandatory pursuant to Minn. R , subp. 18.B. 8. An EAW was prepared on May 25, A press release containing the notice of availability of the EAW for public review was provided to media serving the project area on May 29, The public comment period for the EAW began on May 29, 2000, and ended on June 28, One comment letter from the Minnesota Historical Society was received during the 30-day comment period. Responses to comments received have been prepared by MPCA staff and are hereby incorporated by reference

4 CRITERIA FOR DETERMINING THE POTENTIAL FOR SIGNIFICANT ENVIRONMENTAL EFFECTS 11. In deciding whether a project has the potential for significant environmental effects, the MPCA must consider the four factors set out in Minn. R , subp. 7.A. These criteria are: A) the type, extent, and reversibility of environmental effects; B) cumulative potential effects of related or anticipated future projects; C) the extent to which the environmental effects are subject to mitigation by ongoing public regulatory authority; and D) the extent to which environmental effects can be anticipated and controlled as a result of other available environmental studies undertaken by public agencies or the project proposer, including other Environmental Impact Statements (EISs). The MPCA findings with respect to each of these issues are set forth below. TYPE, EXTENT, AND REVERSIBILITY OF ENVIRONMENTAL EFFECTS The first factor that the MPCA must consider is the "type, extent, and reversibility of environmental effects," Minn. R , subp. 7.A. The MPCA findings with respect to each of these issues are set forth below. 12. Fish, Wildlife, and Ecologically Sensitive Resources. No critical habitats, threatened or endangered species are known to exist in the vicinity of the project. Treated effluent from the stabilization ponds will be discharged to the Willow River in accordance with the provisions of the NPDES Wastewater Permit. The effluent limits in the discharge permit are established to protect water quality standards for the receiving waters and their designated uses. The MPCA finds that the project will not have extensive and/or irreversible environmental effects related to wildlife resources. 13. Potential Impacts on Water Quality. All wastewater entering the WWTF is generated at residential and commercial sources. The proposed effluent limitations are intended to protect the uses of, and prevent degradation to, the receiving waters. In this case the receiving water is the Willow River, a multiclassified designated use water (2B, 3B, 4A, 4B, 5 and 6). The proposed limits, which would be included in the facility s discharge permit, are as follows: Five-day carbonaceous biochemical oxygen demand: 25 milligrams per Liter (mg/l) Total Suspended Solids: 45 mg/l Fecal Coliform Group Organisms: 200 organisms per 100 milliliters ph: Phosphorus: a limit may be imposed The MPCA finds that the project will not have extensive and/or irreversible environmental effects related to water quality

5 14. Physical Impacts on Water Resources. The outfall at the new pond will discharge to the Willow River using the existing outfall structure. Also, the new force main, which needs to cross the Willow River, will be installed by boring under the river to avoid streambank erosion and restoration problems. Consequently, MPCA finds that the project will not have extensive and/or irreversible physical impacts upon the Willow River or any other water resource. 15. Potential for Groundwater Contamination. No adverse impacts on ground water are expected. The proposed additional pond will contain a synthetic liner, which will mitigate the potential for ground-water contamination. Also, the integrity of the existing ponds has been evaluated and found not to be causing any adverse ground-water effects. MPCA finds that the project will not have extensive and/or irreversible environmental effects related to ground-water contamination. 16. Water-related Land Use Management Districts. The land where the proposed treatment ponds will be constructed is within the Cass County-regulated shoreland zoning district, which comprises a ¼ mile zone adjacent to this part of the Willow River. The county ordinance requires sewage treatment systems to be located at least 100 feet away from the ordinary high water level (OHWL), and structures must be located no closer than 150 feet to the OHWL. As the new wastewater treatment ponds are proposed to be located 200 feet away from the OHWL, and no structures are proposed to be built within the 150 feet setback area, the proposal is compatible with the shoreland provisions of the county ordinance. 17. Erosion and Sedimentation. The potential for erosion during repair and extension of the collection system will exist until the roadway and vegetative cover is re-established. Similarly, the potential for erosion during construction of the new treatment pond will also exist until the work is complete and the dikes have been vegetated. The project will be subjected to the conditions of a NPDES permit for discharge of stormwater run-off from the construction sites, including developing an erosion control plan and incorporating best management practices to prevent potential stormwater pollution. Site-specific erosion control plans have been completed, which include silt fencing, straw bale sediment traps, temporary and permanent seeding, and mulching. Disturbed areas for the collection system portion of the project will be restored to pre-construction conditions. Areas disturbed for the treatment ponds will be seeded with a Minnesota Department of Transportation (MnDOT) specified grass seed mix. MPCA finds that the project does not have extensive and/or irreversible environmental effects related to Erosion and Sedimentation. 18. Dust, Odors and Noise. A certain amount of dust is unavoidable during construction; however, this will be minimized by using dust control measures, primarily the use of water sprayed from a water truck, and by minimizing the time it takes to establish temporary or permanent vegetative cover on exposed soils. The collection system extension and repair work will create some shortterm noise impacts, which will be mitigated by limiting construction activity to daylight hours (7:00 a.m. to 7:00 p.m.). The heavy equipment that will be used for the pond construction will also generate noise; however, as no residences are within one-quarter mile of the pond site, this is not anticipated to be a problem. The stabilization ponds typically generate odors for a brief period (three to seven days) each spring when the ponds lose their ice cover and the contents are mixed. The MPCA finds that the project does not have extensive and/or irreversible environmental effects related to dust, odor or noise

6 CUMULATIVE POTENTIAL EFFECTS OF RELATED OR ANTICIPATED FUTURE PROJECTS The second factor that the MPCA must consider is the "cumulative potential effects of related or anticipated future projects," Minn. R , subp. 7.B. The MPCA findings with respect to this factor are set forth below The current collection and treatment system was designed in the 1960s and parts of the system were updated in the 1980s. The new ponds and collection system are being designed to handle the existing demands placed on the system, and also to provide enough capacity to handle the anticipated growth of the City for the next 20 years and possibly some orderly annexation. The City s 20 year growth is estimated at 20 percent. The potential annexation is estimated to add an additional 50 new residential connections to the system. The proposed effluent limits would be protective of water quality and of species in the receiving water. The project enables approximately 50 households that are currently using ISTSs to be connected to the wastewater collection system. Many of these ISTs are known to be failing and out of compliance with applicable requirements. The connection of these households would thereby eliminate the potential ground water and human health threat these systems pose. 26. The MPCA finds that there are no related or anticipated future actions which could result in cumulative, adverse, environmental effects. THE EXTENT TO WHICH THE ENVIRONMENTAL EFFECTS ARE SUBJECT TO MITIGATION BY ONGOING PUBLIC REGULATORY AUTHORITY The third factor that the MPCA must consider is "the extent to which the environmental effects are subject to mitigation by ongoing public regulatory authority," Minn. R , subp. 7.C. The MPCA findings with respect to this factor are set forth below. 25. The following permits or approvals will be required for the project: Unit of Government Permit or Approval Required FEDERAL: a. U.S. Department of Agriculture (USDA), Rural Utilities Service b. USDA Rural Development c. USDA Rural Development Loan and Grant Program NEPA Environmental Assessment Facility Plan d. USDA Rural Development Plan Review - 6 -

7 STATE: e. Mn Dept. of Trade and Economic Development Small Cities Development Program Grant f. MPCA Facility Plan g. MPCA NPDES Permit Stormwater h. i. j. k. l. m. MPCA MPCA MnDOT MN Department of Natural Resources (MDNR) LOCAL: Cass County Cass County NPDES Permit Wastewater Discharge State Disposal System Permit (Sewer Extension) Utility Permit (Right-of-way access) Utility Crossing License/Protected Waters Permit Reclassification of Land Use/Zoning District Conditional Use Permit 26. Description of the Scope of Key Permits/Approvals: a. USDA. Federal funding has been earmarked for this project. In order to receive such funding, the proposal is required to complete a federal environmental assessment and to gain the approvals specified above. The federal environmental assessment process has been completed, and a Findings of No Significant Impacts was issued on November 18, b. MPCA. The MPCA will prepare and issue a NPDES permit (wastewater discharge), which will contain conditions to ensure that wastewater loadings to the facility will be given adequate treatment, following a 30-day public comment period. A General NPDES Stormwater permit is required for projects that will disturb five or more acres, and it requires the permittee to mitigate the potential adverse effects from erosion and sedimentation during construction. c. MDNR. A MDNR Utility Crossing License/Protected Waters Permit is required for the force main which will be constructed beneath the Willow River. The permittee is required to abide by all conditions to ensure that this activity will not negatively impact this protected water. d. Cass County. The proposed treatment pond will be located in an area outside of the City limits. Since that land is currently zoned as residential, a rezoning request must be approved, and a conditional use permit granted, for the pond to be constructed at this location

8 27. The MPCA finds that the permits and monitoring reports that are required by public regulatory authority will provide additional opportunity to mitigate the environmental effects of the project, if necessary. THE EXTENT TO WHICH ENVIRONMENTAL EFFECTS CAN BE ANTICIPATED AND CONTROLLED AS A RESULT OF OTHER AVAILABLE ENVIRONMENTAL STUDIES UNDERTAKEN BY PUBLIC AGENCIES OR THE PROJECT PROPOSER, INCLUDING OTHER EISs. The fourth factor that the MPCA must consider is "the extent to which environmental effects can be anticipated and controlled as a result of other available environmental studies undertaken by public agencies or the project proposer, including other EISs," Minn. R , subp. 7.D. The MPCA findings with respect to this factor are set forth below. 28. The proposed project: repairing and expanding the City s WWTF collection system and constructing the additional treatment pond, has been reviewed by the MPCA staff There are no elements of the project that pose the potential for significant environmental effects which cannot be addressed in the project design and permit development processes. The MPCA finds that the environmental effects of the project can be anticipated and controlled as a result of environmental review, previous environmental studies, and permitting processes undertaken by the MPCA on similar projects. CONCLUSIONS 1. The EAW, the permit development process, the facility planning process, and responses prepared by MPCA staff in response to comments on the Remer Wastewater Treatment Facility Expansion EAW (the project), have generated information adequate to determine whether the project has the potential for significant environmental effects. 2. Areas where the potential for significant environmental effects may have existed have been identified and appropriate mitigative measures have been incorporated into the project design and permits. The project is expected to comply with all MPCA standards. 3. Based on the criteria established in Minn. R , the project does not have the potential for significant environmental effects. 4. An Environmental Impact Statement is not required. 5. Any findings that might properly be termed conclusions and any conclusions that might properly be termed findings are hereby adopted as such. Karen A. Studders, Commissioner Minnesota Pollution Control Agency Date - 8 -

9 COMMENTS AND RESPONSES TO COMMENTS Remer Wastewater Treatment Facility Expansion 1. Britta L. Bloomberg, Deputy State Historic Preservation Officer, Minnesota Historical Society, dated, January 27, Comment 1-1: The commenter stated that: a) there are no properties listed on the National or State Registers of Historic Places, and there are no known or suspected archaeological properties in the area that will be affected by this project; and b) the no response to EAW question 25a is appropriate. Response: The comment is noted (no response necessary).