STATE OF MINNESOTA MINNESOTA POLLUTION CONTROL AGENCY IN THE MATTER OF THE DECISION ON THE NEED FOR AN ENVIRONMENTAL IMPACT STATEMENT FOR THE PROPOSED SHETEK AREA WASTEWATER COLLECTION AND TREATMENT SYSTEM FINDINGS OF FACT MURRAY COUNTY CONCLUSIONS OF LAW CURRIE, MINNESOTA AND ORDER FINDINGS OF FACT Pursuant to Minn. R. 4410.1000 - 4410.1600 (2003), the Minnesota Pollution Control Agency (MPCA) staff has prepared an Environmental Assessment Worksheet (EAW) for the proposed project. Based on the MPCA staff environmental review, comments, and information received during the comment period, and other information in the record of the MPCA, the MPCA hereby makes the following Findings of Fact, Conclusions of Law, and Order: FACILITY HISTORY Project Overview 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 (City) Wastewater Treatment Facility (WWTF) to treat a total Average Wet Weather Flow (AWW) of 319,000 gallons per day (gpd). The WWTF would serve Currie, as well as developed areas within the SAWSC. Ultimately, the project is designed to accommodate an additional 297 Equivalent Domestic Units (EDUs) (connections) of future growth, for a total of 983 EDUs. The expanded WWTF would be located east of the City, 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, and 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. Previous Environmental Review The existing Currie wastewater treatment facility has never undergone environmental review since its flows did not meet the thresholds which require development of an EAW. As a result of the proposed expansion, Minnesota Rules require that an EAW be developed. TDD (for hearing and speech impaired only): (651) 282-5332 Printed on recycled paper containing at least 30% fibers from paper recycled by consumers Shetek Area Wastewater Collection and Treatment System Findings of Fact Currie, Minnesota Conclusions of Law And Order Compliance History The facility was initially constructed in the early 1970’s and upgraded in 2000. The facility was last issued a National Pollutant Discharge Elimination System (NPDES) Permit in 2000. There is no history of compliance problems with the existing Currie WWTF. PROPOSED PROJECT DESCRIPTION Proposed New Construction/Proposed Modification 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, and would discharge treated effluent to the West Fork of the Des Moines River. Sewage Collection System The entire length of sewer pipe that would be needed to service the project area is 33.8 miles. 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 of the project 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. 2 Shetek Area Wastewater Collection and Treatment System Findings of Fact Currie, Minnesota Conclusions of Law And Order 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. 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. 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 A. Land Crossings The majority of the sewer pipe would be installed on land surrounding area lakes using conventional methods, such as open trench construction. Open trench construction activities would include excavation, pipe installation, backfilling, grading, compacting, de-watering, and re-vegetation of disturbed areas. 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. 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) 3 Shetek Area Wastewater Collection and Treatment System Findings of Fact Currie, Minnesota Conclusions of Law And Order 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. 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. In most instances, the sewer pipe would be placed within the road right-of-way or on the house-side opposite the lake and would be approximately 150 to 300 feet from the lake. The pipe would be buried six feet below the soil surface. B. Water Crossings Forcemain will cross the lake in seven places. Waterbody crossings for the forcemain are to be completed using directional drilling techniques. The starting–stopping points for directional drilling will be 200 feet from the lakeshore at a minimum, wherever feasible. The pipe would be drilled eight feet below the bottom of the lake to prevent impacts to the lake’s ecosystem and to prevent freezing of the pipes during harsh winter conditions. WWTF - 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. Wastewater treatment at the existing Currie WWTF is currently accomplished using a three-cell stabilization pond system. The proposed Regional WWTF would consist of 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’s three existing ponds. The land is currently being used for agricultural purposes.