September 10, 2004
TO: INTERESTED PARTIES
RE: Shetek Area Wastewater Collection and Treatment Project
Enclosed is the Environmental Assessment Worksheet (EAW) for the proposed Shetek Area Wastewater Collection and Treatment Project, Murray 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 September 13, 2004 issue. Comments will be accepted through October 13, 2004. In addition to the EAW, the MPCA’s draft National Pollution Discharge Elimination System (NPDES) Permit will also be available for public comment concurrently. The contact person for the Permit is Lisa McCormick at (320) 214-3786.
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 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) 296-7306.
Please note that comment letters submitted to the MPCA do become public documents and will be part of the official public record for this project.
If you have any questions on the EAW, please contact Lynne Kolze of my staff at (651) 282-5992.
Sincerely,
Beth G. Lockwood Supervisor, Environmental Review Unit Operations and Environmental Review Section Regional Environmental Management Division
BGL:gs
Enclosure 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) 296-7398. 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: Shetek Area Wastewater Collection and Treatment Project
2. Proposer: Shetek Area Water and Sewer 3. RGU: Commission Minnesota Pollution Control Agency
Contact Person Chris Hansen Contact Person Lynne Kolze
and Title Water Resources Administrator and Title Project Manager
Address 2500 - 28th Street, P.O. Box 57 Address 520 Lafayette Road North
Slayton, Minnesota 56172 St. Paul, Minnesota 55155
Phone (507) 836-6148 ext. 156 Phone (651) 282-5992
Fax (507) 836-8904 Fax (651) 296-7782
4. Reason for EAW Preparation: EIS Mandatory Citizen RGU Proposer Scoping EAW X Petition Discretion Volunteered
If EAW or EIS is mandatory give EQB rule category subpart number and name: Minn. R. 4410.4300, subpart 18 Wastewater Systems
5. Project Location: County Murray City/Twp Currie
Along or within portions of Sections 19, 20, 29, 30, 31, 32, Township 108 North, Range 40 West; Along or within portions of Sections 13-15, 21-27, 35, 36, Township 108 North, Range 41 West; Along or within portions of Sections 6-10, 15, 16, Township 107 North, Range 40 West; and Along or within portions of Sections 1, 2, 11, 12, Township 107 North, Range 41 West.
TDD (for hearing and speech impaired only): (651) 282-5332 Printed on recycled paper containing 30% fibers from paper recycled by consumers
Figures for the EAW:
Figure 1 Site Location – County Map; Figures 2A-2G U. S. Geological Survey Quad Map; Figure 3 Service Area; Figures 4 Stabilization Pond Location Map; Figure 5A-5C Minnesota Department of Natural Resources (DNR)/U.S. Fish and Wildlife Service (USFWS) letters; Figure 6A-6E National Wetland Inventory Map; Figure 7 DNR Protected Waters Inventory Map; Figure 8A-8C Soils Maps; and Figure 9 Minnesota Historical Society State Historic Preservation Office (SHPO) response letter dated September 11, 2003.
6. Description:
a. Provide a project summary of 50 words or less to be published in the EQB Monitor.
The Shetek Area Water and Sewer Commission (SAWSC), Murray County, is proposing to construct a new sewage collection system around area lakes and expand the city of Currie’s wastewater treatment facility (WWTF) to treat a total Average Wet Weather Flow (AWW) of 319,000 gpd (gpd). The WWTF would serve Currie, as well as developed areas within the SAWSC.
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 would cause physical manipulation of the environment or would 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
Portions of Lake Shetek’s and Lake Sarah’s shoreline is densely developed with both seasonal and permanent homes. Three islands in Lake Shetek are also fully developed. An estimated 614 permanent and seasonal homes, as well as, 17 business connections (total of 686 equivalent domestic units [EDUs]) are included within the SAWSC. The commercial developments include a restaurant and bar, a hotel, campgrounds, and a State Park.
Wastewater treatment is currently provided by individual on-site septic systems. A significant number are not in conformance with the requirements of the state on-site septic system regulations (Minn. R. ch. 7080). In December 1996, a water quality study was completed for Murray County, which evaluated the wastewater and water needs for the lakeshore areas of Lake Shetek, Lake Sarah, Fremont Lake, and Bloody Lake. As a result of this study, the SAWSC was formed.
Proposed Project
Based on the condition of the current on-site septic systems in the area and projected sanitary service needs of the Lake Shetek area, the SAWSC proposes to construct a new sewage collection system and expand the city of Currie’s existing WWTF. The expanded (regionalized) WWTF would continue to treat wastewater from the city of Currie, as well as accommodate flow from the new service area around some area lakes (Figures 1-2).
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 2 Worksheet
Ultimately, the project is designed to accommodate an additional 297 EDUs of future growth, for a total of 983 EDUs. The city of Currie’s WWTF currently has an AWW of 87,000 gpd. After the proposed project is completed, the AWW for the regionalized system would be 319,000 gpd. The expanded WWTF would be located east of the city of Currie, and would discharge treated effluent to the West Fork of the Des Moines River.
Construction of the proposed project is expected to begin in the summer of 2005. The project would be divided into four parts – three parts would involve construction of the wastewater conveyance system, the fourth would involve the construction of the new wastewater stabilization ponds. The collection and treatment facility system is scheduled to begin operation in the summer of 2006.
Sewage Collection System
The entire length of sewer pipe that would be needed to service the project area is 33.8 miles (Figures 1-3). This would include 10.5 miles of gravity sewer pipe, 25 lift stations, and 23 miles of forcemain. The proposed conveyance system would be placed along established roadways and easements, where feasible. In addition, a portion (a total of 6100 linear feet) of the sewer pipe would be routed eight feet beneath the lakebed. The intent is to serve existing homes and businesses primarily along the shoreline of Lake Shetek, Lake Sarah, the Inlet, Smith Lake, Park Lake, Fremont Lake, Bloody Lake, and Armstrong Slough.
The proposed sanitary sewer collection and conveyance system would commence on the northeast side of Lake Sarah along North Shore Drive, Lazy Lake Lane, and Benjamin’s Road. Wastewater would then be conveyed by forcemain south along the U.S. Highway 59 right of way to 201st Street (County Road [CR] 16) where it would tie into a forcemain which is directing wastewater flow collected from the south side of Lake Sarah along Pioneer Trail and Shady Lake Road.
Wastewater would then be conveyed by forcemain along the 155th Avenue and 201st Street (County Road 16) right of ways to the intersection of U.S. Highway 59 and 201st Street (CR 16). All wastewater flows from Lake Sarah would then be conveyed easterly along the north right of way of 201st Street (CR 50) to 180th Avenue and continue easterly to a point of intersection with the forcemain serving the Inlet development area (Pioneer Lane).
The sanitary sewer collection and conveyance system would convey flow from the Brasco Enterprises Camp Site on Armstrong Lane on the northeast side of Lake Shetek westerly to Bluestem Road, Owanka Lane, Dudley Drive to Koch Circle, and then northerly along Teepeeotah, Eastlick Trail and Dear Path Road. Wastewater from Dear Path Road would be conveyed along the north shore of Lake Shetek within the right of way for Sandbar Road, across the inlet where it intersects with the forcemain from the inlet.
Sanitary sewer flows from Lake Sarah, the Inlet and the northeast and north sides of Lake Shetek would be conveyed southerly along the westerly side of Lake Shetek within the Pleasant View Road and Lakeview Drive right of ways to the intersection with Valhalla Road (CR 13).
Sanitary sewer flows, including that from Edgewater Bay and Lakeview Drive, would be routed easterly on Valhalla Road (CR 13) to the southerly point of Keeley Drive. Sanitary sewer flows would then be pumped by forcemain across Lake Shetek through the Boy Scout Camp, to the main lift station located on Hudson Road.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 3 Worksheet
The sanitary sewer collection system would also be routed along the south shore of Lake Shetek from Sioux Trail, through the Baptist Camp to South Shore Drive, and then underneath Lake Shetek to Hudson Road. Wastewater from the State Park would be pumped by forcemain to the collection system on Smith Lake Drive and Foreman Road to Hudson Road.
The Main Lift Station would pump the collected wastewater flows from all the service connections within the service area via forcemain to the WWTF located approximately 1.5 miles east of the city of Currie. The forcemain route would begin at Hudson Road, continuing to 166th Street, then easterly on 166th Street to County Road 38, southerly along County Road 38 to 161st Street, easterly 1 mile to the intersection with 210th Avenue, southerly along a property line for 0.5 mile, and easterly for 0.5 mile, to the WWTF site.
Sewer Construction Methods
Conventional construction methods would be used for sewer and forcemain installation, including trench excavation and backfilling of collection system and forcemain piping. The sewer pipe would be placed within the road right-of-way or on the house-side opposite the lake. Generally speaking, the pipe alignment would be approximately 150 to 300 feet from the lake.
Waterbody crossings for the forcemain are to be completed with directional drilling pipe installation methods. Directional drilling of sewer pipe is becoming a common practice in Minnesota. In situations where the forcemain is being directionally drilled under a lake, the starting–stopping points for the directional drilling will be 200 feet from the lakeshore at a minimum, wherever feasible. The pipe would be drilled six feet beneath the soil surface or in the case of lake crossings, eight feet below the bottom of the lake. At this depth, the sewer pipe will not freeze.
The entire length of the sewer line would be installed in accordance with accepted engineering practices and would be leak tested prior to use to insure there are no leaking joints or cracked piping. Conveyance lines would be placed on granular bases to prevent movement or undue pressures on the lines. Gravity lines would be constructed of pipe appropriate for sanitary sewer construction. Gravity pipe joints would be gasketed. Forcemains would be pressure-rated polyvinyl chloride or ductile iron pipe. Ruptures in forcemain pipe are not common and typically are more likely to occur in piping that is very old or compromised. In the unlikely event that a leak would occur under the lakes, shutoff valves would be employed upstream of the ruptured pipe to minimize the spill, and the damaged pipe would then be promptly repaired. Due to the nature of the project, the potential for impacts to ground water or surface water would be minimal.
Flows are monitored at each lift station upstream and downstream of every forcemain lake crossing. Smaller lift stations contain alarms for high and low wet well water levels. Each of these lift stations also have run-time meters that are checked daily. Larger lift stations (L.S. #1 ,5, 6, 7, 8, 9, and 10) are further monitored by a SCADA System. The SCADA System monitors and records alarms and flow trends of all data for the aforementioned lift stations. SCADA computer, printer, and related items will be installed at the Water Treatment Facility in Currie, Minnesota. Remote access software will be included to allow remote monitoring and diagnostics of the system by the operator via a standard dial-up telephone line. By monitoring lift station flows, the operator will be made aware of any problem in the forcemain.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 4 Worksheet
Open Trench construction activities would include excavation, pipe installation, backfilling, grading, compacting, de-watering, and re-vegetation activities. Equipment to be used would include standard construction machinery such as trucks, backhoes, graders, compactors, skidsteers, cranes, loaders, compressors, and de-watering pumps.
The proposed sanitary sewer line would include sections that are forcemain and sections that are gravity flow. Forcemain pipe sizes would range from 4-inch to 12-inch pipe, with some 1.25-inch to 2-inch pipe associated with individual home grinder stations. Gravity flow pipe sizes would range from 8-inch to 12- inch pipe. Locations of the different pipe types and installation methods are depicted on the attached figures. The following is a breakdown of the collection system piping that would be installed:
• Force main (Directional Drilled) 50,000 L.F. (9.5 mi) • Force main (Open Cut) 73,000 L.F.(13.8 mi) • Gravity Sewer (Directional Drilled) 1,300 L.F. (0.3 mi) • Gravity Sewer (Open Cut) 54,000 L.F.(10.2 mi) TOTAL 178,300 L.F.(33.8 mi) *Linear Feet (L.F.) * Miles (mi)
Where homes cannot be served by a gravity sewer due to topographic constraints, the wastewater generated from the home would be “lifted” to the wastewater collection system located within the right- of-way with a grinder pump station. The grinder pump grinds waste material into small particles. This enables the use of inexpensive, small diameter pressure pipes to transport wastewater to the collection system. Generally, the grinder pump station would be installed between the home and the collection system, with a small diameter pressure pipe drilled underground to connect with the collection system located within the right-of-way.
The forcemain must cross Lake Shetek in areas which are delineated in the attached figures. It is expected that the pipe would be installed by horizontal directional drilling methods in order to prevent disturbance to the lake’s ecosystem. Horizontal drilling involves drilling a pipeline six feet underneath the lake bed to avoid disturbing bottom sediments or causing habitat impacts. Wetlands encountered along the path of the sewer pipe would also be avoided with the use of directional drilling methods.
A number of known cultural resources sites have been identified in the vicinity of the sewer alignment. Archeologists, hired by the proposer, have been working to identify additional sites. If the archeologists determine that the project could result in significant impacts to cultural resources along the sewer pipe’s proposed alignment, it would be routed around those sites. Another option would involve placing the pipe under important sites using directional drilling techniques. If any identified burial mounds are encountered, they would be completely avoided by re-routing the pipe.
Wastewater Treatment Facility - Stabilization Ponds
Sewage collected from the service area would be routed to the Currie Regional WWTF, located approximately 1.5 miles southeast of Lake Shetek and 1 mile east of the city of Currie (Figure 4). Wastewater treatment at the existing Currie WWTF is currently accomplished using a three-cell stabilization pond system. The proposed Regional WWTF would be expanded to a total of six ponds. The three new stabilization ponds (encompassing approximately 50 acres) would be located on a 60-acre site just east of the city of Currie’s three existing ponds. The land is currently being used for
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 5 Worksheet
agricultural purposes. The system would be designed such that there would be two three-pond systems operating in parallel. Both three-pond systems would outlet to the same discharge point in the West Fork of the Des Moines River.
The new facility would also include pond piping, control structures, a pond liner, and the installation of riprap to stabilize the pond dikes. Construction activities and equipment used would generally be the same as that described above for construction of the collection system.
The proposed stabilization ponds would be designed such that they provide effective ground-water protection. At least four feet of separation between the bottom of the pond and ground water is required. The liner would be required to meet the MPCA seepage rates of no more than 500 gallons per acre per day. This would be verified after construction through a water balance test. Erosion would be kept at a minimum with control devices, such as silt fencing, bale checks, riprap, and woven fiber blankets.
The proposed stabilization ponds would provide a 180-day detention time. Effluent from the stabilization ponds would be discharged twice a year, once in the spring and again in the fall when stream flow is typically higher. The facility would be designed to meet the 20-year growth needs of the planning area.
c. Explain the project purpose; if the project would be carried out by a governmental unit, explain the need for the project and identify its beneficiaries.
The purpose of the project is to provide permanent wastewater collection and treatment facilities to the residents, businesses, and other entities in the SAWSC area. These systems are intended to replace all on-site septic systems in the proposed service area, some of which are believed to be adversely impacting water quality in the area lakes as well as polluting some shallow wells.
The need for the new wastewater collection and treatment system was recognized in the summer of 1994, when Murray County conducted a septic system survey around Lakes Shetek, Bloody, Sarah, Armstrong, and Fremont. Based on that survey, Murray County estimated that five to ten percent of all homes have neither a septic tank nor a drainfield, both basic requirements of a conforming on-site system. In addition, an estimated 20 percent of the systems are believed to be failing because they are located in areas where the seasonal high water table is close to the surface (less than three-feet deep). State regulations governing the construction of on-site septic systems require a three-foot separation between the septic tank drainfield and ground water. Many of the remaining septic systems have been improperly maintained and/or are reaching their 25-year life expectancy.
In 1996, the Lake Shetek Area MPCA Phase I Diagnostic Study estimated that the potential pollutant loading from septic systems to the lakes is 376.6 kilograms of total phosphorus per year and 1,280.5 kilograms of total nitrogen per year. Although no formal study has been completed, it is believed that this comprises approximately 10-20 percent of the total loading of phosphorus and nitrogen entering the lake. Agricultural runoff is believed responsible for contributing the majority of phosphorus causing impairments to the lakes (80-90 percent of phosphorus contributed).
Nutrient enrichment in the form of phosphorus contributes to the excessive growth of algal and aquatic weeds in lakes. When algae and plants die, the decomposition process robs the lake of dissolved oxygen used by aquatic life. The more sensitive fish and aquatic species can literally suffocate and die. Lake
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 6 Worksheet
Shetek has experienced a number of fish kills over the years. In addition to causing negative impacts to aquatic life, excess phosphorus can also cause a reduction in water clarity, cause taste and odor problems, and diminish the aesthetic appeal of the lakes.
Pollutants from failing septic systems are also believed to be contaminating some of the shallow private wells around the lakes. Some wells in the area are shallow sandpoint wells which are vulnerable to pollution from a number of sources.
Given that a significant portion of wastewater from the homes around Lake Shetek is not being treated appropriately and the fact that water quality in area lakes is seriously degraded from a number of nonpoint sources of pollution, the SAWSC moved forward to address the problem. A number of alternatives treatment scenarios were reviewed by SAWSC. While the cost of the project is a serious issue for the SAWSC to consider, the EAW only assesses the potential environmental impacts of a project. The cost of a project is outside the scope of the EAW process.
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 conveyance and treatment facilities are designed to accommodate 686 existing EDUs with capacity for an additional 297 EDUs. The facility plan accounts for growth in and around the SAWSC area, but is not purposefully designed for any specific development or other type of growth. Individual connections to the system would occur; other connections for individuals and larger developments may occur in the future if warranted.
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) 177.6 acres (61 ac. for WWTF; 116.6 ac. for or Length (miles) 33.8 miles of pipe pipe)* Number of Residential Units: Unattached NA Attached NA maximum units per building NA Commercial/Industrial/Institutional Building Area (gross floor space): total square feet NA Indicate area of specific uses (in square feet):
Office NA Manufacturing NA Retail NA Other Industrial NA Warehouse NA Institutional NA Light Industrial NA Agricultural NA Other Commercial (specify) NA Building height NA If over 2 stories, compare to heights of nearby buildings NA
*The acreage for construction of the collection system was estimated assuming a 40-foot construction easement.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 7 Worksheet
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.
Shetek Area Water and Sewer Commission – Wastewater Collection and Treatment
Unit of Government Type of Application Status MPCA Nondegradation-to-All-Waters Review Approved March 23, 2004 Currie National Pollutant Discharge Submitted. On public notice Elimination System (NPDES) Permit at this time. Comment period Modification ends October 13, 2004. NPDES General Stormwater Permit for To be submitted Construction Activity Facility Plan Approval Approved Plans and Specifications Review In Progress DNR Temporary Water Appropriations Permit (for To be submitted, if necessary construction dewatering) DNR Water Appropriations Permit (for dewatering To be submitted, if necessary well) License to Work in Public Waters To be submitted, if necessary License to Cross Public Waters To be submitted Natural Heritage and Nongame Database Completed Review LAWCON Right-of-Way Approvals To be submitted SHPO Archeological and Historical Review In Progress Murray County Plan Review To be submitted Utility Permit To be submitted Murray County Conditional Use Permit (ponds) To be submitted Minnesota Department of Plan Review To be submitted Health (MDH) Well Abandonment Permit To be submitted USFWS Federal Threatened and Endangered Species Completed Coordination Minnesota Department of Driveway Access Permit To be submitted Transportation Utility Permit on Trunk Highway Right-of- To be submitted Way (Form 2525) Public Facilities Funding Application (Funding would be To be submitted Authority (PFA) through a PFA low interest loan)
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 land uses in the planning area consists mainly of permanent and seasonal residential development. Other uses include agricultural land, public roadways, small commercial establishments, and recreational facilities. Similar land use is expected to resume after construction. Environmental hazards due to past land uses are not known to exist.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 8 Worksheet The MPCA’s “What’s in My Backyard” Web site was searched for potential contaminated sites which have been identified within the project area. Forty-two Leaking Underground Storage Tank (LUST) sites were identified in Murray County. Only one of these sites appears to be located in the vicinity of the proposed project. The Lake Shetek State Park was identified as a LUST site discovered on April 29, 1993. According to MPCA information, 400 cubic yards of soil were excavated at the site. Monitoring was conducted and the site was formally closed on May 27, 1999. The MPCA issues closure to sites it has determined no longer present a threat to human health or the environment.
10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after development:
Wastewater Conveyance System Before After Before After Types 1-8 Wetlands 0.0* 0.0 Lawn/Landscaping 45.4 45.4 Wooded/Forest 2.0 0.0** Impervious Surfaces 5.4 5.4 Brush/Grassland 30.8 32.8 Other (Gravel) 16.8 16.8 Cropland 16.2 16.2 TOTAL 116.6 116.6
*Wetland acreage is not included in cover type estimates because impacts would be avoided via directional drilling or routing the pipe to go around the wetland areas. Similarly, alignment segments under lakebeds would be directional drilled and are also not included in the cover type estimates.
**Wooded acreage loss is due to clearing above pipe in wooded areas to allow for access and maintenance.
Wastewater Treatment Facility Before After Before After Types 1-8 Wetlands 0.0 0.0 Lawn/Landscaping 0.0 0.0 Wooded/Forest 0.0 0.0 Impervious Surfaces 0.0 0.0 Brush/Grassland 0.0 25.0 Other (Gravel) 0.0 0.5 Cropland 61.0 0.0 Other (WWTF Ponds) 0.0 35.5 TOTAL 61.0 61.0
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.
Stabilization Ponds
The WWTF is located southeast of Lake Shetek. The proposed pond site is a disturbed area, currently used for row crop agriculture. There are many different types of wildlife in the vicinity of the proposed pond facility, including deer, song birds, game birds, and small mammals. Some birds and animals may be displaced either temporarily or permanently as a result of the construction of the proposed facility.
The West Fork of the Des Moines River is the receiving stream for treated wastewater effluent. MPCA would issue a NPDES Permit to protect water quality in the river. The MPCA’s NPDES Permit ensures that fish and aquatic life in the receiving stream are protected during spring and fall discharges, even when the river is at low flow. The permit would include a one milligrams per liter
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 9 Worksheet (mg/L) phosphorus effluent limit, which would reduce phosphorus loadings to area lakes. While some improvements in lake water quality should be expected as a result of this project, the greatest pollutant loadings, resulting from land uses within the watershed, would continue unabated. Ongoing loadings from nonpoint sources of pollution in the watershed will continue to confound efforts to achieve major improvements in lakes’ ecosystems.
Sewage Collection System
The sewage pipeline would be contained within the established right-of-way and easement wherever practical. The majority of mature tree stands, all wetlands and some of the agricultural land would remain as they currently exist, therefore, habitat areas for animals would remain nearly identical. During construction, efforts would be made to limit the size of the disturbed area.
Installation of the pipe systems would require the removal of approximately two acres of trees. Temporary loss of habitat and displacement of wildlife would result. It is expected that the wildlife would temporarily move into adjoining areas, possibly causing territorial conflicts within some species.
Mitigative measures that would be utilized during construction consist of:
1) Utilizing dedicated road right-of-ways wherever possible; 2) Limiting tree removal to only when absolutely necessary; 3) Utilizing acceptable construction procedures and practices; and 4) Minimizing the disturbance of ground cover and tree root systems.
Tree removal would be handled by:
1) Minimizing stripping in the dripline of trees identified to remain. 2) Trimming trees that can be saved, but that interfere with proposed construction. 3) Painting all cuts with wound dressing. 4) Restricting widths of utility trenching. 5) Replanting of some trees that are taken down by the project.
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 19990429 Describe measures to minimize or avoid adverse impacts.
The DNR Natural Heritage and Nongame Research Program was contacted regarding the potential presence of threatened and endangered species or other sensitive ecological resources in the project area. According to the response received (see Figures 5a and 5b), “there are no known occurrences of rare species or natural communities in the area searched.”
The USFWS was also contacted in 1999. According to their response (Figure 5c), one federally listed endangered species is potentially present in the streams and rivers of Murray County – the Topeka Shiner. However, because of the location and type of activity proposed, the USFWS indicated they do not believe the project is likely to adversely affect the species. The response also listed five measures to be taken to minimize the wetland/floodplain impact and other environmental impacts. Most recommendations will be implemented, however, some measures do not apply, as the project proposer is already planning to avoid all wetland impacts. Piping would either be routed
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 10 Worksheet around wetland areas, or would be placed using directional drilling methods beneath the wetlands. In addition, as discussed in item 12 below, all open water crossings would be completed using directional drilling construction methods.
12. Physical Impacts on Water Resources. Would 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 proposed alignment for the collection system crosses open water, wetlands, and a stream in a number of locations. Wetlands identified by the National Wetland Inventory (NWI) in the area of the proposed project are shown on Figure 6. A field survey will be completed to assess the presence of the NWI- identified wetlands as well as any additional wetlands that may be present in the area. Wetland crossings would be avoided by re-routing the pipe around the wetland areas. In order to serve island development within Lake Shetek, the lake crossings are unavoidable. In areas where it is necessary to cross a waterbody, plans are to directional drill the pipe installation under the waterbodies in order to prevent impacts. The pipe will be drilled eight feet below the lakebed.
The DNR Protected Waters Inventory (PWI) map for Murray County indicates several DNR public waters are present within the project area. Figure 7 shows the project area portion of the Murray County PWI map. The PWI waterbodies include: Smith Lake (51-27P), Unnamed lake (51-29P), Fremont Lake (51- 39P), Bloody Lake (51-40P), Lake Shetek (51-46P), Lake Sarah (51-63P), Unnamed lake (51-108P), Armstrong Slough (51-45W), Unnamed wetland (51-64W), Unnamed wetland (51-109W), an unnamed creek connecting Lake Sarah and Lake Shetek, and an unnamed creek connected to the southwestern end of Lake Shetek.
Because of the proposed crossings of some of these waterbodies (see attached figures), a Crossing License from the DNR would be required. Correspondence and discussion with the DNR regarding the crossings has been initiated. Preliminary information from the DNR indicates that they would require the installation of shut off valves at the upstream end of each underwater crossing. The DNR would also require the directional drilling to start and finish at least 200 feet away from the Ordinary High Waterlevel of 1482.6 where feasible. The project proposer is working to address some questions from the DNR regarding erosion control and tree removal/replacement. Plans and specifications would also be submitted to the DNR for their review and recommendations.
13. Water Use. Would 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.
Construction Dewatering Activities
Construction dewatering may be required wherever the pipe foundation is unstable and the water table is above the depth of excavation. No permanent alterations to the water table are expected to occur. If the rate of pumping exceeds 10,000 gpd or 100,000 gallons per year, a temporary water appropriation permit would be required from the DNR. The extent of the trenching would be kept to a minimum. The average width of the construction trench would be 40 feet.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 11 Worksheet Dewatering discharge would be directed to sediment traps or vegetative buffer strips if the discharge is laden with sediment. A filter sock could also be used to trap the sediment and filter the water prior to discharge. If dewatering wells are needed, clean discharge from well point dewatering would be dissipated over the adjacent areas located beyond the construction limits, in accordance with the MPCA’s NPDES Permit.
Abandonment of Some Domestic Wells
A small number of domestic water wells may require abandonment if the required separation distance of 50 feet cannot be maintained between the wells and the sanitary sewer pipe. In these cases, the wells would be properly abandoned in accordance with MDH regulations, and new wells would be drilled.
Seven private wells have been located within 50 feet of the sanitary sewer collection system to date. It is conceivable that additional wells will be located during construction of sanitary sewer facilities. There are two private wells located 15 feet and 25 feet from the sanitary sewer on Sioux Trail on the southwest side of Lake Shetek. There is a private well located 20 feet from the sanitary sewer on Duley Drive on the northeast side of Lake Shetek. There are two private wells on Bluestem Road located 20 feet and 30 feet from the sanitary sewer collection system on the northeast side of Lake Shetek. There are also two private wells located 20 feet and 15 feet from the sanitary sewer on Shady Rest Road on the South Side of Lake Sarah.
Where it is not possible to meet the criteria of 50 feet, a variance is required or the existing private well must be abandoned and a new well provided that meets the setback criteria. Some wells in the area are shallow. The proposer has been informed by the MDH that variances will not likely be permitted. Therefore, where the proposer is unable to meet the 50-foot setback requirement, new private wells will be drilled and the existing abandoned and sealed. The Water and Sewer District will drill and pay for the cost of an equivalent or better new well for the owner.
If the placement of the sanitary sewer line were to have a permanent detrimental affect on any homeowner wells, a new well would be provided to the homeowner to a condition equal or better than the original well and would be paid for by the SAWSC.
All new wells would be constructed by a certified well driller hired directly by the SAWSC. The placement of the new well will be completed as construction activities for placement of the wastewater collection system are occurring. The new wells would be in place before the collection system is approved for operation.
Potential Impacts of Dewatering on Private Wells
Soils for the project area are primarily a loam material with lean clay. Where lean clays are encountered, the trench is expected to be dry. However, there is a possibility that sand lenses or sand pockets could be encountered. The sand pockets will likely be water-bearing and may require the placement of sumps for dewatering purposes during construction. The sumps would be removed upon the placement of the pipe. The contractor would be directed to backfill the trench with the soil material that was excavated and a clay trench block would be installed to prevent the migration of ground water down the bedding of the pipe. Generally, it is expected that subsurface conditions would return to the pre-existing conditions after construction of the pipe is completed.
If private wells go dry due to the temporary dewatering and construction activities, water for drinking purposes would be provided by the Water and Sewer District.
Stabilization Pond Water Balance Test
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 12 Worksheet Pre-filling and water balance testing of the proposed stabilization ponds would require approximately 30,000,000 gallons of water. The water would be supplied by pumping from the West Fork of the Des Moines River, a temporary well, or from another source as approved by the DNR. Plans for this activity have not been finalized, however, staff of the DNR do not anticipate any problems during the testing period. DNR staff would require that the test be accomplished during a period where streamflow is average to high, such as in the spring of the year. Mitigation measures to prevent impacts to the river and its wildlife (fish, etc.) would be needed if the water would be drawn from this source.
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 proposed wastewater stabilization ponds are not located in the 100-year floodplain, however, part of the outfall discharge would be located in the 100-year floodplain of the West Fork of the Des Moines River. In addition, portions of the proposed collection system would be located in floodplain areas of the West Fork of the Des Moines River, the area lakes and small streams. As required, all facilities would remain operational in a 25-year flood and protected from physical damage in a 100-year flood event.
Portions of the project would be located in shoreland areas. Shoreland areas around lakes represent a 1,000-foot boundary from the lakes; shoreland areas adjacent to creeks, streams, and rivers represent a 300-foot boundary on either side of the waterways. Murray County has adopted a shoreland ordinance that applies to development within these areas. The Land Use Plan chapter of the Murray County Comprehensive Plan (most recently published in 2001-2002) lists Lake Shetek, Lake Sarah, Bloody Lake, and the Inlet as developable lakes within Murray County. However, the Land Use Plan recommends that no additional development be allowed on Lake Shetek until adequate infrastructure is in place. The Conservation, Parks, and Open Spaces chapter of the Comprehensive Plan categorizes Lake Shetek and Lake Sarah as General Development Lakes; it categorizes Bloody Lake, Armstrong Slough, Smith Lake, Park Lake, and Fremont Lake as Natural Environment Lakes.
Rules associated with the Shoreland Management District portion (Section 16) of the Murray County Zoning Ordinance are generally in place to protect water quality in the lakes. Subdivision 12 of Section 16 addresses the requirement for sewage treatment and indicates that publicly owned sewage treatment must be used where available. It also indicates that nonconforming sewage treatment systems are regulated and must be upgraded. Subdivision 15 indicates that a permit is required for the installation/alteration of sewage treatment systems. Subdivision 8 of Section 16 is titled “Shoreland Alterations” and addresses both topographic and vegetative alterations. The rules indicate that construction of sewage treatment systems is exempt from the vegetation alteration standards. However, they indicate that the grading and filling standards listed in the Topographic Alterations/Grading and Filling section must be incorporated into the issuance of permits for construction of sewage treatment systems. The standards address:
1. Grading/filling in wetland areas; 2. The time in which bare ground is allowed to remain exposed; 3. The use of mulch until permanent soil cover can be established; 4. The need to minimize soil erosion and prevent sediments from reaching surface waters; 5. Stabilization of slopes in a manner acceptable to the local Soil and Water Conservation District (SWCD) and U.S. Natural Resource Conservation Service; 6. Placement of fill or excavation in a manner that does not create an unstable slope; 7. Required review of plans to fill or excavate on a steep slope; 8. Alterations below the NWI of public waters; 9. Alteration of topography; and 10. Placement of riprap.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 13 Worksheet
Standards 2-6 will apply to this project. At this time, it does not appear that the other standards are applicable to the project.
Although a permit from the Murray County Zoning Administrator for the installation of the wastewater collection system is not specifically required, the completed construction plans and specifications along with the Stormwater Pollution Prevention Plan (SWPPP) will be forwarded to the Murray County Zoning Administrator for review, comment, and approval. The installation of individual sanitary sewer connections and abandonment of existing septic systems will be subject to the Shoreland rules and will require a permit from the Murray County Zoning Administrator.
15. Water Surface Use. Would 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.
The project itself would not change the number or type of watercraft on the lakes, however the presence of a sewage collection and treatment system could attract secondary development. This development could result in additional watercraft using the lake over time. Murray County may need to revisit this issue if boat traffic increases on the lakes in the future.
16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: See below acres; See below 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 acreage/cubic yards of soil to be graded or excavated are estimated as follows:
Wastewater Treatment Facility (ponds): approximately 61 acres and 416,000 cubic yards Wastewater Conveyance System: approximately 116.6 acres and 564,000 cubic yards
The Murray County Comprehensive Local Water Plan (1996) indicates that in general, the soils in the Lake Shetek watershed are highly erodible prairie soils (medium to fine textured Barnes-Flom-Vallers and Barnes-Buse). The detailed soils map (Figure 8) identifies several soil types in the project area as eroded. An eroded soil is indicated with a “2” at the end of its soil symbol, as in Barnes loam, three to six percent slopes, eroded (33B2). The table in Item 19 indicates which soils are eroded.
The Murray County Comprehensive Plan (2001-2002) indicates that soils with slopes in excess of 26 percent are considered steep. The table in Item 19 lists three soil types with slopes that range up to 40 percent – Storden loam, 18 to 40 percent slopes (31F); Sioux sandy loam, 2 to 40 percent slopes (402E); and Buse loam, 18 to 40 percent slopes (437F). The locations of these soil types are shown on the attached Soils Map (Figure 8) and appear to be primarily located on the south side of Lake Sarah and portions of the west side of Lake Shetek.
Because this project would involve the disturbance of more than one acre of land, an application for coverage under the NPDES General Permit for Construction Activities would be submitted to the MPCA. The NPDES Permit requires that the applicant and contractor both sign and agree to the permit conditions.
Detailed temporary and permanent erosion control measures have not yet been prepared for the project. As indicated above, these plans would be required as part of the NPDES Permit. Erosion and sediment control measures to prevent impacts to the area wetlands and waterbodies would be implemented prior to any land disturbance activities and would remain in place until vegetation has been reestablished. Regular inspection would insure that measures implemented remain effective.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 14 Worksheet
Specific measures to be implemented may include: silt fence, rock construction entrance, sedimentation basins, check dams, erosion control blankets, and prompt re-vegetation of disturbed areas via seeding and mulch. Original grade contours would be restored after construction and pre-construction drainage patterns would not be altered by the project. Permanent stormwater ponds would be located within the right-of-way or within the easements acquired next to the right-of-way, generally near lift stations.
The sediment and erosion control plans would provide more detail as to the specific measures to be implemented and would also address phasing of construction, vehicle tracking of sediment, inspection of erosion control measures, and the timeframes in which the erosion control measures would be implemented.
Slurry Management
During directional drilling activities, slurry will be generated that will have to be properly disposed of. The project proposer will adhere to the following measures for the handling and disposal of drilling fluid and cuttings:
Handling and Disposal of Drilling Fluid and Cuttings:
1. Make adequate provisions for handling and containing muddy water, drilling fluid, and cuttings during drilling operations. Do not discharge these contaminants into waterways. Handle water and materials to conform with requirements of the agency(s) with regulatory jurisdiction. 2. Construct drilling fluid pits at entry and exit points in a manner that completely contains mud and prevents its escape. 3. When onsite provisions for storing muddy water, drilling fluid, or cuttings onsite are exceeded, haul contaminants away to suitable legal disposal site. 4. Conduct directional drilling operation in such manner that drilling mud is not forced into waterways, wetlands, or the ground surface.
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 stormwater pollution prevention plans.
Sewage Collection System
The quantity and quality of runoff leaving the area around the proposed pipeline trench would not change during construction or after the project is completed. Changes to surface grades and the addition of new impervious surfaces would result in a negligible increase in runoff. The quality of that runoff would not be degraded due to the best management practices (BMPs) that would be implemented during and after the project.
Stabilization Ponds
The new stabilization ponds would retain all of the precipitation that falls within them. All areas around the ponds would be revegetated with grass soon after construction is completed. Grassed areas would encourage nearly all rainfall and snowmelt to percolate into the soil. Runoff coming from the pond site should not contain sediment or pollutants and would not degrade surface water.
Water pumped from the ground to dewater the construction site for the ponds would be handled appropriately (see Items 8, 12, and 16) and according to the requirements of the NPDES Permits.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 15 Worksheet Water quality in the West Fork of the Des Moines River cannot be impaired as a result of this activity.
Summary
In summary, there should be virtually no change in the quantity and quality of runoff from the pond site or the pipeline trench after construction of the project is completed. Proper management of stormwater from the project sites is required by the NPDES General Stormwater Construction Activity Permit. This permit has specific requirements, including the use of whatever BMPs are needed to prevent the degradation of surface water during construction and after the project is competed. The MPCA has met with the proposer to discuss what NPDES Permit requirements would apply and the expectations would be for the stormwater pollution prevention plan. SWPPP and BMP implementation strategies, as well as temporary and permanent erosion control plans, must be and would be prepared prior to submitting a NPDES General Stormwater Construction Activity Permit application.
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.
Sewage Collection System
Receiving water bodies in the vicinity of the proposed project include wetlands, Lake Sarah, Lake Shetek, other smaller lakes and creeks, and ultimately, the West Fork of the Des Moines River. Overland flow is the route runoff must take to reach the lakes and creeks. Slopes in most areas of the project are generally not steep (approximately six percent) and the routes to the water are generally covered with trees or grasslands. These would inhibit the movement of runoff and pollutants to surface water. With the implementation of erosion and sediment control and BMPs, the impact of runoff during construction is expected to be negligible.
Because the sewer pipe would be placed below grade, the disturbance caused by construction of the pipe would be temporary, and because the areas would be quickly reseeded after completion of the project, significant impacts to receiving water bodies are not expected.
Stabilization Ponds
Similarly, stormwater runoff in the vicinity of the new stabilization ponds will not change in any significant way. The ponds would receive and store any precipitation that falls within them. Vegetation around the ponds would be restored as soon as possible after construction. Fiber blankets, mulch and/or hydraulic seeding would be used where necessary to ensure prompt re-
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 16 Worksheet vegetation. The NPDES General Permit for Discharge of Stormwater during Construction Activities would outline specific timeline provisions for re-vegetation. The contractor would comply with these timelines.
Once vegetation has been reestablished, most precipitation would gradually seep into the ground around the pond sites. Runoff in the vicinity of the ponds may increase only minimally due to a 0.5 acre gravel access road.
18. Water Quality – Wastewater.
a. Describe sources, composition and quantities of all sanitary, municipal and industrial wastewater produced or treated at the site.
Normal domestic sewage would be collected and treated with the proposed conveyance system and WWTF. The new stabilization ponds created as part of this project would treat wastewater generated around portions of Lake Shetek, Bloody Lake, and Lake Sarah in Murray County. The wastewater, including that generated by commercial users, would be of domestic strength. No industrial wastewaters would be treated at the new WWTF. The following table shows the composition and quantity of the municipal wastewater to be treated at the WWTF:
Parameter • Flow - Average Dry Weather, million gallons per day (mgd) 0.265 - Average Wet Weather, mgd 0.407 - Design Flow, mgd 0.407 • Biochemical Oxygen Demand (BOD) - Average Daily Concentration (mg/L) 177
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.
Nondegradation Review
The proposed expansion of the city of Currie’s WWTF meets the definition of a “significant discharge” under Minn. R. 7050.0185, subp. 2G. A significant discharge is defined as an expanded discharge of sewage, industrial, or other wastes that expands by more than 200,000 gpd or more. A Nondegradation of All Waters Review was required for the proposed project to determine whether the expanded facility should be required to perform additional treatment of its wastewater. The Nondegradation Review was completed and approved by MPCA on March 23, 2004. No additional treatment requirements beyond those required of a nonsignificant discharger were applied to this facility.
The newly expanded facility would be required to treat wastewater to the level that ensures the propagation and maintenance of a healthy community of cool and warm sport or commercial fish and associated aquatic life, and their habitats. The water must also be suitable for all kinds of aquatic recreation, including bathing.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 17 Worksheet
The West Fork of Des Moines River is the receiving stream for the effluent from Currie’s regionalized WWTF. The Des Moines River eventually drains to the Missouri River system. The Des Moines River has been given use classifications of 2B, 3B, 4A, 4B, 5 and 6, which are described below:
• Class 2 waters -- aquatic life and recreation. • Class 3 waters -- industrial consumption. • Class 4 waters -- agriculture and wildlife. • Class 5 waters -- aesthetic enjoyment and navigation. • Class 6 waters -- other uses.
The WWTF effluent would be discharged to the West Fork of the Des Moines River, which flows 15-20 miles before entering Talcot Lake. Talcot Lake is a shallow, hyper-eutrophic (overly enriched) lake that was monitored by the MPCA during the summer 2002. Summer mean Total Phosphorus and chlorophyll-a concentrations were among the highest found in a statewide shallow lakes study.
Monitoring data for the past three years were used to estimate annual loads of phosphorus to Talcot Lake. The city of Currie’s existing facility (at 87,000 gpd) could potentially discharge up to 265 pounds (lbs.) of phosphorus per year to the lake. Its actual load was approximately half of that. The new facility (319,000 gpd) will be required to meet a one mg/L phosphorus limit. This is approximately one-half of the concentration of phosphorus typically discharged from a pond facility. The concentration of the current facility is approximately one mg/L. Since the new facility will discharge an increased volume of water, the new facility will ultimately discharge 972 lbs. per year at the AWW into Talcot Lake.
The new facility will contribute 1 to 2 percent of the total load of phosphorus to Talcot Lake during an average to dry year and approximately 0.5 percent of the total load during a wet year. Based on the hyper-eutrophic status of Talcot Lake, removal of phosphorus to one mg/L would not reduce the abundance of algae in the lake or increase water clarity significantly. However, the MPCA is concerned about the cumulative loads of phosphorus to the lake. Removal of phosphorus to one mg/L by the city of Currie would minimize the impact of the expanded discharge as a portion of the cumulative load to the West Fork of the Des Moines River and Talcot Lake.
The over-abundance of algae is an issue for the Des Moines River, downstream of Currie and all other reaches of the Des Moines River further downstream, near the Iowa border. The slope of the river is very gradual and inorganic solids are relatively low during average to low flow conditions. These characteristics of the river, coupled with high phosphorus concentrations, are ideal for riverine algal production. There is strong evidence that the Des Moines River has a high internal production of algae. Analysis by MPCA has shown that total phosphorus is positively correlated with total chlorophyll abundance and biological oxygen demand (BOD) in the Minnesota River. The monitoring station on the Des Moines River (WDM-3) had the highest summer average total chlorophyll of all rivers monitored in the state for this study in 2001.
The Des Moines River is on the 2004 Total Maximum Daily Load (TMDL) list for dissolved oxygen, fecal coliform, ammonia, and turbidity impairments. The MPCA is currently working to develop a Total Maximum Daily Load (TMDL) for the Des Moines River downstream of Windom. The Total Phosphorus-Chlorophyll-BOD linkage has not been established for the Des Monies River system at this point in time. In an effort to protect downstream waters from further degradation, a 1 mg/L phosphorus limit was established in the proposed effluent limits for the facility.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 18 Worksheet
To protect designated uses of the Des Moines River, the expanded WWTF would have to meet all of the following effluent limitations:
Substance or Characteristics Limiting Concentration or Range 5-day biochemical oxygen demand 25 mg/L Total Suspended Solids 45 mg/L Fecal Coliform 200 organisms/100 milliliters pH (Range) Not less than 6 or greater than 9.0 Phosphorus 1 mg/L (monthly average)
Phosphorus removal would be accomplished by applying alum to the ponds on a periodic basis. The MPCA would also require the city of Currie to monitor odors, vegetation in ponds, ice cover, precipitation, and other factors that could influence the effectiveness of the pond system. The city of Currie would be allowed to discharge treated effluent from the ponds between April and October of each year.
The Proposed Facility
The wastewater collected by the proposed conveyance system would be treated by a new three-cell stabilization pond system at the Currie WWTF.
The two primary treatment ponds would measure 570 feet by 920 feet. The secondary treatment ponds would each be approximately 1150 by 480 feet in size. Wastewater would be pumped directly to the primary treatment ponds, where natural physical and chemical processes would break down wastes. These processes would be performed by sunlight, naturally-occurring bacteria, micro- organisms, plants, and algae. Within the primary ponds, the majority of solids would settle to the bottom of the ponds and bacteria would begin to break down oxygen demanding substances. Sunlight (ultraviolet radiation) would provide a natural disinfection process, destroying many pathogens present in the wastewater.
The ponds would be designed to be relatively shallow, at six feet deep, with three feet of freeboard. Shallow depths would allow sunlight to penetrate to the bottom and encourage the proper amounts of aeration and mixing. Shallow depths would also prevent anaerobic (septic) conditions, and the odors associated with them. The bottom two feet of the pond volume is for biosolids storage and treatment.
The ponds would be constructed with a clay liner. The liner would be constructed to maintain or exceed the required separation distance of four feet above groundwater level. Ponds would be constructed so that they do not leak at a rate which exceeds 500 gallons per acre per day.
After primary treatment, wastewater would move to the secondary treatment pond where additional treatment would occur. During secondary treatment, oxygen demanding substances and solids would be significantly reduced. Bacteria and sunlight would again be the active agents in the treatment and disinfection of wastewater.
The ponds are designed to provide 180 days of wastewater storage, and adequate time for waste treatment. Approximately every 180 days, wastewater would be discharged from the ponds through an underground pipe to the West Fork of the Des Moines River via an outfall. This outfall would be also be used by the city of Currie’s existing pond system. Prior to discharge, effluent samples would be collected and analyzed to ensure compliance with the NPDES Permit effluent limits. The treated wastewater would be discharged in a way that would be coordinated with periods in the spring and fall, when the receiving waters are typically at a higher stage and are the least sensitive.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 19 Worksheet No major impacts to the West Fork of the Des Moines River are expected as a result of increasing the wastewater treatment capacity of this facility. Water quality standards are based upon low flow conditions (7Q10) which typically occur during the summer months. Since this facility would discharge only in the spring and fall when stream flow is higher, the effects of the discharge to water quality in the stream is expected to be minimal.
c. If wastes would 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.
Murray County is cooperating with the city of Currie to ensure the smooth operation and maintenance of the WWTF under the NPDES Permit. Pretreatment is required by the Sewer Ordinance for high strength wastewater or for other possible discharges that may affect the performance of the WWTF. Currently there are no known dischargers that require pretreatment facilities. The improvements to the WWTF are fully described in this EAW and are sized to handle the projected wastewater flows.
The city of Currie’s WWTF would be improved to handle 20-year wastewater design flows for SAWSC. Currie’s existing three-cell ponds would continue to serve the city of Currie. The proposed treatment facility improvements include an additional three-cell stabilization pond system that would share an outfall with the existing pond system. As indicated above, both pond sets would operate under the city of Currie’s NPDES Permit. This permit will be revised by the MPCA accordingly. The draft permit for this facility is currently on public notice until October 13, 2004. Comments can be transmitted to Ms. Lisa McCormick at MPCA, Willmar Office, 201 28th Avenue S.W., Willmar, Minnesota 56201.
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: ~ 8 feet minimum; 15-20 feet average. Bedrock: ~ 300 feet minimum; 300-400 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.
Sewage Collection System
Soil borings were completed for the project in 2003. According to the findings of the Geotechnical Exploration and Review report (November 2003), the test borings indicate a general soil profile of surficial fill and topsoil underlain by clay till and varying alluvial deposits. The water table fluctuates with lake water levels, and there may be sand lenses in which perched water is encountered.
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To determine general geologic conditions in the project area, the following publications were researched:
• Regional Hydrogeologic Assessment: Quaternary Geology - Southwestern Minnesota, RHA-2, Part A, published by the Minnesota Geological Survey in 1995 • Regional Hydrogeologic Assessment: Southwestern Minnesota, RHA-2, Part B, published by the Minnesota Department of Natural Resources in 1997 • Geologic Map of Minnesota: Depth to Bedrock, Map S-14, published by the Minnesota Geological Survey in 1982
According to the Surficial Geologic Map contained in Part A of RHA-2, surficial deposits include:
Supraglacial till – Hummocky till with discontinuous lenses of clay, silt, sand, and gravel. Matrix texture is loam to clay loam. Till color and assemblage are similar to that of the Bemis moraine (yellow-brown where oxidized, gray where unoxidized; contains pebbles of carbonate, felsic and mafic igneous rocks, shale, chert, and some lignite), though the till is more deeply oxidized.
Locations: Portions of land between Lake Sarah and Lake Shetek.
Till with stream-modified surface – Till modified by flowing water; locally fluvially eroded and streamlined. Matrix texture is loam to clay loam. Pebble assemblage and till color are the same as that of the Bemis moraine (described above). Locally overlain by thin lag of sand and gravel or covered with silt and clay.
Locations: Surrounding Lake Sarah; on the north, west, and southeast side of Lake Shetek; portions of land between Lake Sarah and Lake Shetek.
Stream sediment behind the Bemis moraine – Sand, gravel, and silt deposited by meltwater issuing from stagnating or receding ice. This soil includes younger and finer glacial and postglacial stream sediment and colluvium.
Locations: Surrounding the inlet; northeast and south side of Lake Shetek; area between WWTF and Lake Shetek.
Geologic hazards are not known or suspected to be present in the project area, based on review of geologic publications and observed conditions in the field.
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.
According to the General Soil Map for Murray County (Murray County Soil Survey, 1990), several general soil associations are present in the project area. The general soil associations include:
• Barnes-Flom-Vallers association: Well drained and poorly drained, nearly level to moderately steep soils that formed in loamy glacial till • Barnes-Buse association: Well drained, gently undulating to very steep soils that formed in loamy glacial till. • Clarion-Webster-Nicollet association: Well drained, poorly drained, and moderately well drained, nearly level to hilly soils that formed in loamy glacial till.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 21 Worksheet • Clarion-Storden association: Well drained, undulating to very steep soils that formed in loamy glacial till. • Arvilla-Egeland-Marysland association: Somewhat excessively drained, well drained, and poorly drained, nearly level to moderately steep soils that formed in loamy material over sandy and gravelly deposits.
General soils information is useful in comparing large areas for general land use, but is not as useful in determining site suitability for specific development or use, such as for the construction of roads, buildings, septic systems, etc. A more detailed analysis of soil suitability can be determined using detailed soil maps from the soil survey and completing soil borings.
Proposed Pond System
Soil borings have been completed for the proposed wastewater collection and treatment system. According to Murray County detailed soil information, the following soil types are present in the area where the proposed ponds will be located:
• 94B – Terril Loam, 2-8 % slopes • 921C2 – Clarion-Storden loams, 6-12 % slopes • 102B – Clarion loam, 2-4 % slopes • 102B2 – Clarion loam, 3-6 % slopes, eroded
Special considerations associated with the soil types are also indicated in the table. Figures 8A-8C depict the locations of the soil types in relation to the proposed wastewater treatment ponds and wastewater collection system alignment. A legend for the figures is provided on a separate page following the maps.
The stabilization ponds would be lined with clay to protect groundwater in the area. The ponds must be constructed so that they do not leak at a rate greater than 500 gallons per acre per day.
Soil Types:
Symbol Soil Name Special Significance 31F Storden loam, 18-40% slopes Steep slopes 33B Barnes loam, 2-4% slopes Prime farmland 33B2 Barnes loam, 3-6% slopes, eroded Eroded; prime farmland 36 Flom clay loam Hydric; prime farmland where drained 51 La prairie loam Prime farmland 70 Svea loam Prime farmland 86 Canisteo clay loam Hydric; prime farmland where drained 94B Terril loam, 2-8% slopes Prime farmland 96A Collinwood silty clay, 0-2% slopes Prime farmland 96B Collinwood silty clay, 2-6% slopes Prime farmland 102B Clarion loam, 2-4% slopes Prime farmland 102B2 Clarion loam, 3-6% slopes Eroded; prime farmland 113 Webster clay loam Hydric; prime farmland where drained 114 Glencoe silty clay loam Hydric; prime farmland where drained 118 Crippin loam Prime farmland 127A Sverdrup sandy loam, 0-2% slopes 127B Sverdrup sandy loam, 2-6% slopes 127C Sverdrup sandy loam, 6-12% slopes 130 Nicollet loam Prime farmland
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 22 Worksheet
Symbol Soil Name Special Significance 141A Egeland sandy loam, 0-2% slopes Prime farmland 141B Egeland sandy loam, 2-6% slopes Prime farmland 184 Hamerly loam Prime farmland 210 Fulda silty clay Hydric; prime farmland where drained 211 Lura silty clay Hydric; prime farmland where drained 212 Sinai silty clay Prime farmland 219 Rolfe silt loam Hydric; prime farmland where drained 229 Waldorf silty clay Hydric; prime farmland where drained 236 Vallers clay loam Hydric; prime farmland where drained 246 Marysland loam Hydric; prime farmland where drained 276 Oldham silty clay loam Hydric; prime farmland where drained 284B Poinsett silty clay loam, 2-4% slopes Prime farmland 284B2 Poinsett silty clay loam, 3-6% slopes, eroded Eroded; prime farmland 339A Fordville loam, 0-2% slopes Prime farmland 339B Fordville loam, 2-6% slopes Prime farmland 341A Arvilla sandy loam, 0-2% slopes 341B Arvilla sandy loam, 2-6% slopes 341C Arvilla sandy loam, 6-12% slopes 344 Quam silty clay loam Hydric; prime farmland where drained 359 Lamoure silty clay loam, frequently flooded Hydric 392 Biscay loam Hydric; prime farmland 402E Sioux sandy loam, 2-40% slopes Steep slopes 418 Lamoure silty clay loam, occasionally flooded Hydric; prime farmland where drained 437F Buse loam, 18-40% slopes Steep slopes 506 Overly silty clay loam Prime farmland 562 Knoke silty clay loam Hydric; prime farmland where drained 902C2 Barnes-Buse loams, 6-12% slopes, eroded Eroded 904B Arvilla-Barnes-Buse complex, 2-6% slopes 904C Arvilla-Barnes-Buse complex, 6-12% slopes 913D Buse-Barnes loams, 12-18% slopes 920C2 Storden-Clarion-Arvilla complex, 6-15% slopes, Eroded eroded 921C2 Clarion-Storden loams, 6-12% slopes, eroded Eroded 960D2 Storden-Clarion loams, 12-18% slopes, eroded Eroded 1030 Pits, gravel-Udorthents complex 1051 Glencoe silty clay loam, ponded Hydric 1356 Water-miscellaneous 1824 Quam silty clay loam, ponded Hydric
In the preceding table, hydric soils were identified using the Hydric Soils of Minnesota list (1995). Prime farmland information was obtained from the Soil Survey of Murray County, Minnesota (1990).
Sewage Collection System
According to the geologic publications reviewed (see 19a), the sensitivity of surficial aquifers to pollution in the project area is moderate to very high. Areas of very high sensitivity are indicated to be present along the Inlet and the northeast, southwest, and southeast sides of Lake Shetek. High sensitivity is also indicated in the area between the proposed stabilization ponds and Lake Shetek. Moderately sensitive areas are present for the remainder of the project area. According to the geologic publication, the estimated travel time for water-borne surface contaminants to reach the water table is hours to months in very high sensitivity areas, and years to decades in areas of moderate sensitivity.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 23 Worksheet Construction contractors would be required to develop spill response plans and to make all project personnel aware of the response plan requirements, including notification to the MPCA/State Duty Officer if a spill or other type of release should occur.
The entire length of the sewer line would be installed in accordance with accepted engineering practices and would be leak tested prior to use to insure there are no leaking joints or cracked piping. Conveyance lines would be placed on granular bases to prevent movement or undue pressures on the lines. Gravity lines would be constructed of pipe appropriate for sanitary sewer construction. Gravity pipe joints would be gasketed. Forcemains would be pressure-rated polyvinyl chloride or ductile iron pipe. Installation of directionally bored sewer pipe is becoming a common practice across Minnesota. Ruptures in forcemain pipe are not common and typically are more likely to occur in piping that is very old or compromised. In the unlikely event that a leak would occur under the lakes, shutoff valves would be employed upstream of the ruptured pipe to minimize the spill, and the damaged pipe would then be promptly repaired. Due to the nature of the project, the potential for impacts to groundwater or surface water would be minimal.
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 would 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 wastewater collection and treatment system would collect and passively process domestic sewage. The three-cell stabilization pond would hold and allow for processing of the domestic wastewater. The open ponds would allow for wind and wave action that would oxygenate the wastewater and facilitate decomposition. Over time, sand and a small amount of sludge may accumulate at the bottoms of the ponds. This necessitates that approximately every 40 years or so, these types of ponds are drained and cleaned out to remove this material. Prior to disposal of this material, it would be tested for potential contaminants and then treated accordingly prior to field application.
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 would lead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize or eliminate the waste, discharge or emission.
During construction, equipment and vehicles utilizing gasoline, diesel fuel, antifreeze, and oil would be used at the project site. Fuel trucks would be at the site during construction. Fueling of vehicles and equipment would be conducted away from sensitive areas.
Chemicals used to remove phosphorus from the wastewater would be added to the stabilization ponds. These chemicals would be added manually using a boat for access, and would not be stored on-site. Presumably, they would be stored indoors in the city of Currie.
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.
A back-up power generator would be located at the main lift station (Lift Station 1) near the Boy Scout Camp north of Hudson Road for use during electrical power outages. A small diesel fuel storage tank would be attached to the generator. The generator would be located within the lift station structure and, thus, any potential releases would be contained.
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Other lift stations would utilize portable power generators that would be brought in temporarily during times of power outages. These generators would be stored in the city of Currie.
21. Traffic. Parking spaces added: NA Existing spaces (if project involves expansion): NA Estimated total average daily traffic generated: NA Estimated maximum peak hour traffic generated (if known) and its timing: NA Provide an estimate of the impact on traffic congestion affected roads and describe any traffic improvements necessary. If the project is within the Twin Cities metropolitan area, discuss its impact on the regional transportation system.
A noticeable permanent increase in traffic would not occur as a result of this project. There will be some increases in traffic resulting directly from the use of construction vehicles. This impact would be temporary and of a relatively short duration. Local roads may be closed to through-traffic for periods of time, and traffic would be detoured in these situations. These roads would remain accessible to local residents. In other areas, temporary roads may be constructed to allow for continued access to an area. An access maintenance plan would be prepared and included in the project specifications with regard to Keeley Island. In this location, there is only one county road available for access and the road would be un-useable during construction due to trenching activities. Space constraints make the construction of a temporary road impossible. To allow residents access to and from the island during this time, transportation would be provided with boats for a period of approximately two to three weeks. A storage lot for vehicles of island residents would be provided on the mainland.
Minimal effects on traffic are anticipated on highways such as state Highway 59, as the pipe would be placed using directional drilling, or would be far enough away from the travel surface that traffic disruption would be insignificant. Directional drilling would be used to place the pipe under County Road 13/Valhalla Road (access to Keeley Island) and County Road 38 between Lake Shetek and the WWTF. Tunneling under these roads is not expected to result in major traffic impacts, although minimal traffic disruption, such as minor slow-downs, may occur during the short period of tunneling.
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.
The project is not expected to alter current traffic volumes, other than temporarily during construction, and thus would not affect vehicle-related air emissions.
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.
Not applicable.
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24. Odors, Noise and Dust. Would 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.)
The nearest receptors to odors, noise and dust are scattered farmsteads, residences, employees, and patrons of businesses located on lakeshores and other areas along the sewer alignment. Average exposure times are estimated to be approximately four to eight weeks in any one area.
Odors, noise and dust would be generated by equipment and machinery during construction. Equipment would include trucks, backhoes, graders, compactors, bobcats, cranes, loaders, compressors, and possibly de-watering pumps.
Odors Odors may be generated from construction equipment exhaust and materials used in the construction process. Odor impacts would be controlled through the limitation of construction hours to daylight or those permitted in local ordinances.
The proposed pond system meets the recommended one-quarter mile separation distance to homes. However, the stabilization ponds may be the source of a certain amount of odor in the spring. This may occur when the ice cover breaks up, the water in the ponds turns over, and gaseous odors, which developed over the winter period, escape to the atmosphere. Odorous conditions are typically of a short duration, lasting three to five days. Guidelines for adequate separation distances from residential dwellings would be met. This would effectively minimize potential nuisance conditions.
As in any sanitary sewer system, there is potential for odors to form during operation of the proposed system. Hydrogen sulfide has the potential to form in sewage material under anaerobic conditions, and can produce a rotten-egg odor, particularly where flow turbulence releases gas from solution in the wastewater. Generally, areas of greater turbulence tend to be at meter stations and lift stations. The addition of chemicals to the sanitary system to suppress growth of the odor-causing bacteria is one option if hydrogen sulfide becomes a problem in the future. Filtering air ventilated from the sewer system through a biofilter is another method of controlling odors, as is utilization of packaged carbon filtration systems.
Noise Noise levels would increase during the course of project construction. The noise level increases would be primarily due to the operation of heavy equipment. The noise increase would be short-term and somewhat localized, and could be mitigated by preventing unnecessary running time of equipment. In addition, construction hours would be limited to daylight, or those times stipulated in local ordinances.
Existing noise levels are not anticipated to significantly increase due to the project facilities when the system is operational. Process equipment such as pumps, which create certain levels of noise, would be housed in small structures, thereby effectively reducing noise to the outside environment. The value and usage of land adjacent to the facilities site would not be adversely affected by operational noise levels.
Dust During construction, fugitive dust may increase temporarily. The effects of dust would be minimized by daily cleanup of the construction site and the use of water trucks to wet the soil and reduce airborne dust, when necessary.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 26 Worksheet 25. Nearby resources. Are any of the following resources on or in proximity to the site?
a. Archaeological, historical, or architectural resources? Yes No b. Prime or unique farmlands or land within an agricultural preserve? Yes No c. Designated parks, recreation areas, or trails? Yes No d. Scenic views and vistas? Yes No e. Other unique resources? Yes No
If yes, describe the resource and identify any project-related impacts on the resources. Describe any measures to minimize or avoid adverse impacts.
Archaeological, Historical, or Architectural Resources
The SHPO was contacted regarding the potential presence of known or suspected cultural resources in the vicinity of the proposed alignment alternatives (Figure 9). According to the response received, SHPO believes “there is a good probability that unreported archaeological properties might be present in the project area” and has recommended that a survey of the area be completed.
A consultant was hired to investigate the project area for cultural resources potential. The Phase I Archaeological Survey is approximately 95 percent complete, excluding DNR property. During completion of the Phase I survey, the field study focused on the project corridor and pond locations. The potential presence of archaeological resources was assessed and shovel tests were completed in areas where lack of significant disturbance indicated the potential for resources to remain. Thus far, 21 new cultural sites have been identified and four previously-identified sites have been revisited.
The high number of sites attests to what appears to be expansive and continuous use of this area and intensive use of its rich resources. Many of these sites are comprised of one or a few lithic flakes (bi- products of stone tool making) found on agricultural fields or in shovel test. These may be representative of a sparse scattering of such artifacts which exist continuously in proximity to the lakes. Other sites are dense, deep, exhibit integrity, and contain a variety of artifacts that can potentially be useful in describing early human activities in the area. These sites may be significant and potentially eligible for listing on the National Register of Historic Places [NRHP]). Should it be determined that certain sites are eligible for listing on the NRHP, meetings would take place with appropriate agencies and individuals to discuss appropriate efforts to mitigate effects to eligible sites.
It is planned that most of the resources would be avoided with the placement of the sewer pipe within roads and right-of-way areas. Other significant areas could be avoided using directional drilling for pipe installation or by routing the pipe around the resource location.
No new cemetery sites were identified and no previously recorded cemetery sites will be impacted by the project based on the current construction plans.
There are currently five sites that are unavoidable and will require further testing (Phase II Evaluation) to evaluate whether the sites are indeed eligible for listing on the NRHP. After the Phase II Evaluation is completed, a Phase I/Phase II report will be submitted to the proposer.
Representatives of the project proposer have met with SHPO staff to discuss the proposed project and the recommended investigation. SHPO is in contact with the Minnesota Indian Affairs Council regarding burial mounds and other sites of potential Native American significance.
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SHPO’s response letter indicated that if the project involves federal funding or requires a federal permit, it should be re-submitted to the SHPO with reference to the federal authority per Section 106 of the National Historic Preservation Act of 1966 and 36CFR800. At this time, it does not appear that the project would utilize federal funds or require federal permits. The U.S. Army Corps of Engineers has been consulted regarding potential permit requirements and has concluded that no permit from the agency would be required, since all wetland disturbances would be avoided using directional drilling or strategic pipe placement. If these conditions change, the project would have to be re-submitted for review per Section 106.
Prime or Unique Farmlands, Lands within an Agricultural Preserve
Nearly 86 percent of the soils in Murray County meet the requirements for prime farmland. The Soils Table in item 19 indicates which soil types in the project area have been designated as prime farmland. Where the collection system crosses prime farmland, it is expected that the piping would be deep enough to allow for farming to continue, once construction has been completed. Portions of the site where the three-cell stabilization pond is proposed, appear to be designated prime farmland. Due to construction of the pond system, these soils would be permanently taken out of production.
Designated Parks, Recreation Areas or Trails
Lake Shetek State Park is located in the project area on the southeast side of Lake Shetek. The park is operated and maintained by the DNR, which has expressed its support of the project. Other parks, trails, and recreation areas are present in the vicinity of the project, although none are identified close to the proposed ponds. Lake Sarah East Park is a county park on the east side of Lake Sarah, off of State Highway 59. Marsh’s Landing is a county park located on Valhalla Island on the west side of Lake Shetek. Lake Shetek/End-O-Line Bike and Pedestrian Trail is a paved six-mile long county trail that connects End-O-Line Park in Currie to the Lake Shetek State Park. Several church camps and a Boy Scout Camp are also located in the project area. The Rupp Wildlife Management Area is present on the south side of 161st Street, approximately one-quarter mile east of County Road 38.
Impacts to parks, trails, and recreation areas would be temporary and would primarily occur during construction. Indirect impacts such as noise, dust, and general disruption caused by construction machinery may occur to users of the facilities during construction of the project. Construction activities may cause temporary direct impacts in some areas where sewer placement is proposed. As the sewer pipe would be placed below grade, permanent impacts are not anticipated. Minor permanent impacts may be visible in park areas where lift stations are proposed.
The DNR has agreed to conduct their own archaeological survey prior to the commencement of their construction on their property.
Scenic Views and Vistas
Scenic views of the area lakes are present in the area and are valued, as indicated by the number of lakeshore residents in the project area. Due to the subgrade nature of the project, any scenic views or vistas that might be present would not be impacted once construction has been completed.
The proposed WWTF site is in an agricultural field. While the pond system with its berms would be visible, its visual impact is not anticipated to be significantly adverse. Significant scenic views or vistas are not considered present in the immediate area of the proposed ponds.
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Other Unique Resources
Other unique resources are not known to be present within the project area.
26. Visual impacts. Would 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.
The pond site is not located near any residences, but would be visible from a distance due to the seven- foot to nine-foot dikes. The dikes would be seeded for vegetation growth, as would the stockpiled soil excavated during construction of the ponds. The pond site would be surrounded by a fence. View impacts are not expected to be significantly adverse.
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 would be resolved. If no, explain.
The proposed project is subject to the Murray County Comprehensive Plan (Draft, 2001-2002), the Murray County Comprehensive Local Water Plan (1996), as well as local ordinances and policies regarding shoreland protection, floodplain, water quality, and development issues. As the project would utilize the city of Currie’s WWTF discharge site, it is also subject to coordination with the city of Currie.
This project is a direct result of provisions identified in Goal 1, Objective A of the Murray County Comprehensive Local Water Plan:
Goal 1: Improve the quality of Murray County’s surface water to enhance recreation and economic opportunities.
Objective A: Protect County Lakes, especially Lake Shetek and Lake Sarah from potential pollution caused by private septic systems and other sources.
1. Encourage Lake Shetek Area Improvement Association and People Around Lake Sarah to pursue development of water and sewage systems.
2. Assess all developed residential lakes in Murray County for pollution potential.
a. An assessment would be made to determine what effect septic systems are having on lake water quality. b. Provide opportunities to all lake homeowners to become part of a central sewage collection and treatment system, if feasible. c. Encourage efforts to seek funding for a feasibility study for central sewage systems on all developed residential county lakes. d. Recommend to Murray County Planning and Zoning that all future plats around all developed residential county lakes be required to have a centralized sewer system.
According to the Local Water Plan, the MPCA monitored Lake Shetek in 1985 in their regional survey of lakes and characterized the lake as hypereutrophic, based on low Secchi disc readings and frequency and severity of algal blooms. Local groups, county organizations, and concerned citizens have expressed
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 29 Worksheet concern with the deteriorating water quality of the lake. The implementation plan recommends institution of shoreland and watershed practices to address the problem of deteriorating water quality, including septic system upgrades to centralized sewer where possible.
Key issues identified in various chapters of the Murray County Comprehensive Plan include:
• Water quality/shoreland development • Lack of centralized and/or managed sewer around the lakes • Poor water quality in most lakes • Continued support for centralized sewer systems
The Comprehensive Plan indicates that changing development along lakeshores over time (short-term use to long-term and more intensive use on small lots) has resulted in too much sewage and lack of treatment, leading to loss of water quality. The Comprehensive Plan recommends that all development on Lake Shetek be halted until adequate infrastructure is in place. The Comprehensive Plan states, “there should be adequate controls concerning setbacks, stormwater management, density requirements and lot size, maximum amounts of impervious surfaces, and sewage treatment.”
Regarding shorelands, the Comprehensive Plan lists as one of its goals:
Goal 2: Protect county lakes from potential pollution caused by private septic systems and other sources.
Objective: To protect water quality, wildlife species, and wildlife habitat.
Policies 1. Limit development on the county’s lakes until adequate infrastructure is in place (centralized and/or managed sewer system). 2. Continue to place importance on the Sewer District and support its continuation.
Implementation strategies listed are the same as that listed above under Objective A of the Water Plan, numbers 1, 2b and 2c.
The proposed project is in direct support of the goals, policies, and objectives of the plans it is subject to.
28. Impact on infrastructure and public services. Would new or expanded utilities, roads, other infrastructure or public services be required to serve the project? Yes No If yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is a connected action with respect to the project must be assessed in the EAW; see EAW Guidelines for details.)
The creation of the new wastewater district would require the establishment of a governing board. In addition, an individual would be hired for operation and maintenance of the new facilities.
Private hook-ups to the wastewater collection system would be needed. These connections would presumably be constructed by local contractors hired by individual property owners along the wastewater collection system route.
The lift stations would require that power distribution be expanded. It is anticipated that the power can be obtained from adjacent areas.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 30 Worksheet
The existing roadways would be disturbed for sanitary sewer placement, but would be returned to existing or better conditions.
One new road would be required for access to the stabilization ponds. This road would be constructed of gravel (approximately 0.5 acre) and would receive minimal traffic, thus causing minimal environmental impact.
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).
Several backlots and lots on the shoreline adjacent to the proposed sanitary sewer line are currently vacant. It is assumed development adjacent to the collection system would occur. The trend for Murray County has been a decreasing population since 1940, but moderate population growth is expected because of the proximity to the lake recreation area. No cumulative environmental effects are expected as a result of the moderate growth rate expected in the planning area. The facilities are designed for an additional 297 EDUs over the next 20 years in addition to the existing 686 EDUs.
In general, the availability of utilities encourages additional development in a service area. However, as indicated previously, only moderate growth is expected to occur in Murray County. Development would be encouraged in accordance with current zoning and land use requirements and would comply with applicable local ordinances and state codes and regulations intended to manage, minimize or eliminate any adverse impacts. Increased development would also result in increased traffic, air pollution, stormwater runoff, and solid waste generation. As residential and commercial areas expand, the amount of farmland, open space and wildlife habitat in an area would decrease to some degree. The communities within the service area would need to regularly assess and address impacts that would occur due to the secondary development.
Increased development would also result in increases in impervious surfaces and an increase in the amount of precipitation that may run off into surface waters. Any construction project that disturbs more than one acre of soil would be required to comply with the requirements and conditions set in the NPDES General Stormwater Permit for Construction Activity. Facilities such as stormwater treatment and stormwater detention ponds could be used to treat increased runoff.
Individual development projects in the future may be subject to environmental review and the preparation of project-specific EAWs or an Alternative Urban Areawide Review. Future sanitary sewer extensions would require a permit from the MPCA.
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.
Not applicable.
31. Summary of Issues. List any impacts and issues identified above that may require further investigation before the project is begun. Discuss any alternatives or mitigative measures that have been or may be considered for these impacts and issues, including those that have been or may be ordered as permit conditions.
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Discussion of Alternatives
A 1995 feasibility study reviewed thirteen different alternatives under three wastewater treatment strategies. The wastewater treatment alternatives reviewed in the study included stabilization ponds, extended aeration mechanical treatment plants, regionalization with the city of Currie, cluster on-site wastewater treatment systems, wetlands, and spray irrigation systems. The three treatment strategies were one centralized treatment location, treating Lake Sarah and Lake Shetek areas separately, and cluster on-site systems to serve the entire study area. The feasibility study recommended regionalization with the city of Currie so that new stabilization ponds would be built to serve the city of Currie, Lake Shetek and Lake Sarah.
In January 1999, another engineering consultant expanded upon the feasibility study to a complete facility planning document. This facility plan was later amended in May 1999, September 2000, and October 2001. The three most feasible options from the feasibility study were reexamined and two additional alternatives were considered. The two additional alternatives looked for ways to make the project more economical by consolidating the collection system and removing remote users that added to the overall project cost.
The SAWSC selected the alternative that is outlined in this EAW. Three additional wastewater stabilization pond cells are to be constructed at the city of Currie wastewater treatment site to treat the proposed project area.
RGU CERTIFICATION.
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. 4410.0200, subps. 9b and 60, respectively. • Copies of this EAW are being sent to the entire EQB distribution list.
Name and Title of Signer: Beth G. Lockwood, Supervisor, Environmental Review Unit Operations and Environmental Review Section Regional Environmental Management Division
Date:
The format of the 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, 651-296-8253, or at their Web site http://www.mnplan.state.mn.us.
Shetek Area Wastewater Collection and Treatment Project Environmental Assessment Currie, Minnesota 32 Worksheet
ERRATA SHEET
for the
SHETEK AREA WASTEWATER COLLECTION AND TREATMENT PROJECT ENVIRONMENTAL ASSESSMENT WORKSHEET
The following errors have been found in the published EAW. Corrections are provided below:
Page 5, 4th Paragraph, Sentence 3
The EAW states “horizontal drilling involves drilling a pipeline six feet underneath the lakebed…”
The EAW should read, “horizontal drilling involves drilling a pipeline eight feet underneath the lakebed...”
Page 11, 5th Paragraph, Sentence 3
The EAW states that “if the rate of pumping exceeds 10,000 gallons per day or 100,000 gallons per year, a temporary water appropriation permit would be required from the DNR.”
The EAW should read, “if the rate of pumping exceeds 10,000 gallons per day or 1,000,000 gallons per year, a temporary water appropriations permit would be required from the DNR.”
Page 17, Table on Parameters and Flow
The EAW states that Average Wet Weather Flow and the design flow (in millions of gallons per day) will be 0.407 mgd.
The EAW should state that these flows will be 0.319 mgd.
Page 10, 2nd Paragraph, Sentence 2
The EAW states, “The majority of tree stands, all wetlands, and some of the agricultural land would remain as they currently exist, therefore, habitat areas for animals would remain nearly identical.”
The EAW should state that “the majority of tree stands, most wetlands and some of the agricultural land would remain as they currently exist, therefore, habitat areas for animals would remain nearly identical.”
Most wetlands will be avoided completely by directionally boring the sewer pipe underneath them. No impacts to the wetlands will occur in these cases. In a few other cases, minor, temporary impacts to some undelineated wetlands may occur, particularly in depressions and low areas. In these areas, the pipe will be installed using a trenching method of excavation. It is estimated that impacts may affect a total of approximately 0.25 acres of land. In these cases, excavation in these areas would occur as follows.
1
If good quality wetland plant species are present, a minimum of one foot of bottom sediment will be salvaged and re-spread over disturbed wetland areas during restoration to replace the native seedbed. If wetland areas are highly disturbed and are dominated by invasive species, the topsoil would not be reused; instead, the restored wetland areas would be seeded with a native wetland seed mix. In either case, the original grade contours would be restored after construction, and therefore, pre-construction drainage patterns would not be altered by the project. Prior to construction through any wetland areas, a Wetland Conservation Act Certificate of Exemption would be required as approval for the temporary impacts to the wetlands due to the utility construction.
Page 11, 2nd sentence
The EAW states, “Piping would either be routed around wetland areas….”
The EAW should state, “Piping will be routed around nearly all wetlands, or….”
Map of Proposed Service Area
A corrected service area map has been included as an attachment to this document.
2