RECORD OF DECISION FINAL ENVIRONMENTAL IMPACT STATEMENT BEMIEJI WASTEWATER TREATMENT SYSTEM BELTRAMI COUNTY, MINNESOTA United States Environmental Protection Agency Region V Chicago, Illinois Approved by: Valdas V. Adamkjfcs <^ Acting Regional Administrator ------- Record of Decision Final Environmental Impact Statement Wastewater Treatment System City of Bemidji Beltrami County, Minnesota On May 15, 1981, USEPA, Region V published an official Notice of Availability of the Final Environmental Impact Statement (EIS) for the wastewater treatment system for Bemidji, Minnesota in the Federal Register. Consistent with the regulations of the Council on Environmental Quality, 40 CFR 1505.2, USEPA is providing this public Record of Decision as the final step in the EIS process. GSEPA Decision It is the decision of this Agency to approve the facilities plan for the City of Bemidji. Approval of the facilities plan allows Step 2 (engineering design) and Step 3 (construction) work to proceed with the aid of Federal and State construction grants funds. This decision is based on the analysis presented in the Final EIS document. The approved wastewater treatment alternative for Bemidji is the construction of a new 2.0 M<3> advanced-secondary wastewater treatment plant (WWTP) at the site of the existing WWTP. Treated effluent from the new plant will be discharged directly to the channel between Lake Irving and Lake Bemidji. The new WWTP will incorporate the following treatment processes to attain an effluent level of 25 mg/1 of EGD, 30 mg/1 of suspended solids and a phosphorus level of 0.3 mg/1: primary clarification; activated sludge secondary treatment; two-stage alum and polymer addition prior to and after secondary clarification; granular-media filtration; disinfection and discharge. The Minnesota Pollution Control Agency (MPCA) issued the NPDES permit containing the aforementioned effluent limitations on May 26, 1981 after receiving no dissenting opinions during the 30-day comment period for the permit. Background There is a need for the City of Bemidji, Minnesota, to improve the quality of the effluent discharged from its wastewater treatment plant (WWTP) to the Upper Mississippi River. The WWTP effluent constitutes the first major discharge of treated wastewater to the Mississippi River. The effluent phosphorus contributes to the total loading of phosphorus in Lake Bemidji and the Upper Mississippi River Chain of Lakes downstream from Bemidji (Wolf Lake, Lake Andrusia, and Cass Lake, within the Leech Lake Indian Reservation). These lakes are utilized for recreational fishing, swimming, boating, hunting, and rice production and are an integral part of the local tourist-based economy and the Native American Indian culture. In 1978, the City of Bemidji was required by the MPCA Board to provide for interim control of phosphorus at the existing WWTP and to relocate the point of discharge from the Mississippi River downstream from the Lake Bemidji outlet to the inlet of Lake Bemidji. This order was based on the Board°s decision that the eutrophication problem should be reduced to the maximum extent possible with interim measures until a new WWTP with advanced phosphorus removal capability or a land treatment system could be implemented. The improvement in the quality of the downstream lakes since these improve- ments were implemented in June 1978 has been significant, as evidenced by 1979-1980 water quality data; however, the quality of Lake Bemidji is being adversely affected. ------- -2- Alternatives Examined in the BIS An exceptionally large number of wastewater treatment system alternatives have been investigated as potential solutions to the problem of wastewater disposal at Bemidji. Six of these wastewater treatment system alternatives were evaluated in the EIS; these alternatives were determined to represent the most feasible treatment options available to the City. They included five conventional treatment systems and one land treatment system. For each conventional alternative, two phosphorus treatment options were addressed: reduction of the effluent phosphorus concentration to 1.0 mg/1, and reduction of the effluent phosphorus to 0.3 mg/1. Alternative 1 proposed the construction of a new 2.0 MGD advanced-secondary WWTP at a site presently owned by the City adjacent to the Mississippi River about 2000 feet downstream from the Lake Bemidji outlet. Alternative 2 proposed the construction of a new 2.0 MGD advanced-secondary WWTP at the site of the existing WWEP in Bemidji. The effluent would be pumped via a new force main to the Mississippi River immediately downstream from the Lake Bemidji outlet for discharge. Alternative 3 proposed the construction of a new 2.0 MGD advanced-secondary WWTP at the site of the existing WWTP in Bemidji. Discharge would be directly to the Mississippi River inlet Channel to Lake Bemidji adjacent to the plant site. Alternative 4 proposed the construction of a new 2.0 MGD advanced-secondary WWTP at the site of the existing WWTP in Bemidji, with effluent pumped via a new force main to Grass Lake, northwest of Bemidji, for discharge. Alternative 5 proposed the construction of a new 2.0 MGD advanced-secondary WWTP at a site adjacent to Grass Lake with effluent discharged directly to the lake. Alternative 6 proposed preliminary treatment of the raw wastewater at the site of the existing WWTP. From there it would be pumped via a new force main to aerated ponds in Section 16 of Eckles Township northwest of Bemidji. Pond effluent would then be applied to 1,170 acres of forest land via a irrigation system and to 250 acres of cropland with a center-pivot irrigation system. Underdrainage would be required, with collection and discharge, to open ditches. See Exhibit A for cost comparisons of the alternatives. Though only one land treatment alternative was considered in the EIS, the concept of land treatment has received a thorough examination. It has been considered by some as the best solution because it would eliminate the direct discharge of effluent to the Upper Mississippi River system. As a result, numerous land treatment proposals have been developed and considered in detail through at least five separate search efforts (1972, 1976, 1978, 1979 and 1980). These searches have identified many potential sites, some very close to the City and others as distant as 25 to 30 miles. Soil borings and more detailed geotechnical investigations were conducted at a number of the more promising sites. At the conclusion of each search effort, land treatment has been rejected because of unacceptable social, economic and/or environmental impacts. ------- -3- Draft BIS Preferred Alternative Alternative 3 was the preferred alternative presented in the Draft EIS. The estimated capital costs to achieve effluent phosphorus concentrations of 1.0 mg/1 and 0.3 rag/1 were $9,975,000, and $12,904,000, respectively. The annual O&M costs were $417,000 and $525,000, respectively. Alternative 3 was the most cost-effective, especially when compared to the land treatment option which had an estijnated capital cost of $24,457,000 and a projected annual O&M cost of $612,000. It also is the alternative that would have the least potential for significant adverse construction and operational impacts. Response to Draft EIS Considerable public response was received on the Draft EIS, both in writing and through testimony at the public hearing held on September 11, 1980 at Bemidji. Despite the number of land treatment proposals studied and rejected in the past, significant concern was expressed by downstream interests concerning the absence of a feasible agricultural wastewater irrigation alter- native and the lack of discussion of the economic benefits of clean water downstream in the Draft EIS. The City proposed an "Alternative 7" concept, which was to have been a viable, on-land alternative east of Bemidji, to be developed by the City prior to December 1980. While there was considerable support for the inclusion of "Alternative 7" in the Final EIS, there also was significant criticism ex- pressed at the potential to further delay the EIS process and the implementa- tion of a solution by considering yet another land treatment proposal. Residents of Frohn and Eckles Townships, where "Alternative 7" was to be located, were especially vocal in their opposition to the proposal. In an effort to provide the technical basis for the establishment of a phos- phorus effluent limitation for a new WWTP, the MPCA prepared a document, dated December 15, 1980, which is a Supplement to the State Draft EIS and was con- sidered as a formal comment on the Federal Draft EIS. The Supplement address- ed the cost for construction and O&M of a new WWTP, the cost to users, the economic benefit to the downstream recreation-based economy from improved water quality, and alternative projections of water quality associated with various levels of phosphorus reduction. The information in the MPCA Supplement demonstrated that there will be water duality benefits associated with phosphorus treatment to the 0.3 mg/1 level. The reduction of phosphorus to 0.3 mg/1 will preclude acceleration of nutrient enrichment of Lake Bemidji and will provide the maximum practicable protection for the downstream Chain of Lakes. The design proposal examined in the Supplement provides for a filtration system which is necessary to attain an effluent phosphorus limit of 0.3 mg/1. If at a later date additional treatment facilities are found to be necessary to maintain an effluent phosphorus level of 0.3 mg/1, funding of such facilities would be subject to further review and approval. ------- -4- During the period that the MPCA was preparing its Supplement, the City pro- ceeded to develop further its "Alternative 7" proposal with the assistance of engineering consultants. They concluded, as previous studies of the same areas had, that because of site limitations (i.e., poorly suited soils and high water table conditions), cropland irrigation could not be accomplish- ed in a cost-effective manner. Only low rates of application are suitable because of the glacial till in Prohn Township. Because the short growing season at Bemidji limits the application season, wastewater must be stored during an extended period (at least 7 months), requiring large amounts of land for irrigation during suitable conditions. Subsequently, the City Council determined that the high cost of an agricultural wastewater irrigation alter- native at the site in Eckles Township also eliminated it from further consid- eration. The Maple Ridge alternative, located approximately 25 miles north of Bemidji, was the final land treatment option considered by the City under the "Alter- native 7" concept. This proposal called for storage of wastewater in natural boglands for withdrawal by area farmers for cropland irrigation. The total construction cost was estimated to be $17,459,000 and an annual O&M cost of ?273,000. Both MPCA and this Agency informed the City that they could not support further study of the Maple Ridge alternative because of its high cost and the many engineering and environmental concerns associated with the proposal. Final EIS Preferred Alternative Based on the response to the Draft EIS and the additional information in MPCA°s Supplement, we concluded that the technically feasible, environ- mentally and socially acceptable cost-effective solution to Bemidji°s wastewater problem was the construction of a new 2.0 MO) advanced-secondary wastewater treatment plant at the site of the existing plant with discharge to the Mississippi River channel to Lake Bemidji. MPCA's revised construction cost estimate for the new plant, which will be capable of attaining an effluent phosphorus level of 0.3 mg/1 is $11,945,000. The revised annual O&M cost is $362,000. A sludge disposal plan for four sites in Bemidji Township has been approved DyJfla^L^. MPCA evaluated the plan to determine whether me analysis o£ environmentally safe sludge application levels contained in the plan is consistent with its criteria. Application of the existing Sludge Disposal Plan to the proposed situation once the new WWTP is operational will require further MPCA approval. The sites proposed in the plan have adequate capacity to accommodate the additional sludge from the new WWTP for more than the 40- to 50-year life of the plant. Monitoring reports on the sludge disposal activities will be required annually by MPCA and routine site inspections will be periodically conducted by MPCA staff to determine whether the approved sludge disposal plan is being implemented properly. ------- -5- Sevecal methods of wastewater disinfection are still under consideration. Chlorination, the most widely used process, must be followed by dechlori- nation to meet NPDES permit requirements. Other disinfection alternatives, including ultraviolet light and ozonation, have the potential for providing effective disinfection while being less detrimental to streamlife and not reacting instream to form new compounds. They have the disadvantages of higher costs and a technical difficulty in readily knowing when a satisfactory level of disinfection is achieved. Hie selection of the disinfection method will be made after a cost effective comparison in Step 2. Manor Environmental Impacts of the Final EIS Preferred Alternative Direct impacts from the construction of a new wastewater treatment plant at the site of the existing WWTP will be localized to the treatment plant site and will consist mainly of short-term construction-related nuisance conditions. The 2.0 MS) design capacity of the new plant will allow for reasonable growth in the Bemidji service area. The expenditure of nearly $12 million for construction will provide a direct economic stimulus and will induce secondary income and expenditures. The most significant operational impacts are related to the level of phos- phorus loading reduction attainable in Lake Bemidji and the downstream Chain of Lakes, and the cost to system users for treatment system opeation. By limiting the WWTP effluent phosphorus concentration to 0.3 mg/1, the water quality of Lake Bemidji will be improved and the maximum praticable reduction in phosphorus loadings to the Chain of Lakes will be attained. This will result in reversal of the trend towards advanced eutrophication in these lakes that was initiated in 1955 when the City began discharging effluent directly to the Upper Mississippi River downstream of Lake Bemidji. Cur regulatory requirements for proportionate user charge systems for grantees will necessitate a revision of Bemidji's existing rate structure. Although the O&M and debt service costs associated with the new treatment plant are expected to be significantly higher than current WWTP costs, residential user costs are projected to remain close to the current level (because of the con- version of the rate structure). However, conmercial users, including the University, are projected to pay higher user costs for wastewater service in the future. Wild and Scenic River On December 30, 1976, the Secretary of the Interior, through the Bureau of Outdoor Recreation, determined that the construction of a WWTP at Bemidji would have no direct and adverse impact on the quality of the proposed Upper Mississippi Wild and Scenic River. Furthermore, the protection of the Upper Mississippi as a Wild and Scenic River under P.L. 90-542 expired on August 25, 1980. ------- Mitigative Measures 1. Construction Impacts Direct impacts from the construction of the new WWTP at the site of the existing WWTP will consist of fugitive dust, emissions from construction equipment noise, and the occasional interruption of traffic flow. Fugitive dust should be controlled by periodically wetting spoil-piles and unpaved access roads or by covering them with matting or mulch to reduce susceptibility to wind erosion. Trucks transporting spoils to disposal sites should cover their loads. Proper maintenance of construction equipment and application of emission control devices should minimize emissions of hydrocarbons and fumes. Construction activities should be scheduled to avoid evening and night work to avoid disturbance during periods of low background noise. 2. Erosion and Sedimentation Erosion and sedimentation must be minimized at the construction site. USEPA has established requirements for erosion and sedimentation control in PEN 78-1. The requirements include providing plans and specifications for erosion and sediment control, discussing specific control measures in the Operation and Maintenance Manual and reviewing the control measures during construction inspection. 3. Archaeological/Historic Preservation No archaeological or historic sites are known to exist at the WWTP site. A portion of the proposed site already was disturbed by excavations during construction of the existing plant. There is a possibility, however, that archaeological resources exist on undis- turbed portions of the site that could be damaged by excavations for new treatment units. The State Historic Preservation Officer should be consulted during Step 2 design work regarding the need for a detailed archaeological survey. If archaeological resources are discovered on the site, the site layout may have to be altered or the resources salvaged to permit construction. 4. Ploodproof ing The extreme southeastern portion of the proposed WWTP site is within the 100-year lake floodplain. No construction activities are proposed for that area, although future plant expansion in that area of the site may be required. Appropriate floodproofing measures would then be required for future facilities in that area. ------- Summary comparison of costs of advanced-secondary wastevater treatment options for the six alternatives considered for Bemldll, Minnesota In the EIS (based on RCM 1979 b and 1980). Note that MPCA has refined the estimated cost of achieving a 0.3 mg/1 phosphorus level for Alternative 3 to an estimated $11,945,000 for construction cost and $362,000 for O&M. w Alternative 1 (IILU Mlddlj^lp^l River plant allu wltli dluclur,;u lo till.: River) l.U •B/l r Liic.l construction com 11.174 ^•.JtiCJl u'urc 7,'J'Jl il Hd »li. ITU 1,5yd Ucal jlitrd l.7Bi K Anu.i-l U..i: 411 t*:to Toui Total .'-: ..uj t.O~ I j i S.M.. •i i j -jicj aalva^i: value 1,911 l-rckcnl wo ri!i caul 15.tt'j6 e-.ulvilcru atinu.il cost 1.515 l>jr I.O'JO Djllona 9 2.0S (« $1.000) 0.1 aj/l r U.litl ID.OJ7 i,lM1 2.254 SJ'J 1.VJ1 IU.966 1.UII7 $ 2.61 Altarnailvc 2 Alternative 1 (nun plant at existing alto (new plant at with d 1 uchfl rt|il Jluch.ir^c lo Laku Klvcr) (» 51,000) lli-ifl.||l) (« 51,000) 1.0 n^/1 P 11.649 a.idi 1.617 l,Ui9 417 1.901 16.2"J4 1.347 9 2.12 Cut Li.-l.i-o juiiiji: l.il c.ijiltul cot.1 for necJuil aaaar ii-it incliiu^ Oiil cor collect luu : o.i ?J >cjfj Ji 7.125; liiicccjt >yuteu ($6 , ratu. .50/uuiilli 0.1 n.C/1 f 14.57d I0.2JO 2.046 2. J02 515 l.'JUl 19.291 i. ma 9 2.65 uyutdia fur uvui on Intoruiuilon or 1.0 0B/1 L> 9.975 7.009 1.402 1,565 417 3.184 14,3)1) 1.16d 9 1.87 0.1 »B/l V* I2.V04 9.055 1.811 2,11)7 525 3.184 17.000 1.678 9 2.30 Alternative 4 (nuu plant at exlutliic alia with Jtu- cturnu to Urajj Luke) (K $1.0(10) 1.0 13.2'JH 9.J15 1.067 2.0C8 492 4.381 18.452 1.758 9 2.40 0.3 •i/l t 16.219 11,162 2.276 2, Sol 6UO 4,381 21.4U8 2,040 9 2.94 Altarnattvc 5 Alternative 6 (»uw pi en l At Ctoaa (l»ni L.ikvi Jltli .11*- tr>:.ilti:<>iit at cliurud to Graja Ecklud Tc'.na'ilp fjUj) (x $1.000) »ltc) (x 51, CCO ) 1.0 uu/l P 12,912 9.046 t.m 2.029 492 4,151 10.094 1,724 9 2.16 0.3 15.U61 11.112 /.22Q 2.5i)i 60U 4,151 21.057 2.007 9 2.S9 24.417 19.451 2.0c'J 2,y;6 612 7,l!/l Zi.^OJ 2.754 9 4.03 laproycmu n t u. •act: hoiiiiuliolJ In I960). cue n led la MrCA fl98Q'j) • — aca Table 2-4. Similar coal revlalo CIS Alsd JU^lV E iilvun 1, 2. 4. juJ 5; Bucli rcvlulunu uoulJ not affect the proparclonutu differences la cost among the alternatives. ------- |