Lake Minnetonka Area Regional Interceptor EAW

TDD (for hearing and speech impaired only): 651-282-5332 Printed on recycled paper containing 30% fibers from paper recycled by consumers

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 651-297-8510. 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: Lake Minnetonka Area Regional Interceptor Improvements Project 2.

Proposer:

Metropolitan Council Environmental Services

3.

RGU:

Minnesota Pollution Control Agency

Contact Person Deborah Manning Contact Person Jessica Ebertz and Title Principal Engineer and Title Project Manager Address 390 North Robert Street Address 520 Lafayette Road North St. Paul, Minnesota 55101 St. Paul, Minnesota 55155-4194 Phone 651-602-1114 Phone 651-296-8011 Fax 651-602-1083 Fax 651-297-2343 4. Reason for EAW Preparation:

EIS Scoping

Mandatory EAW

X

Citizen Petition

RGU Discretion

Proposer Volunteered

If EAW or EIS is mandatory give EQB rule category

subpart number and name: Minn. R. 4410.4300, subp. 18 Wastewater Systems

5.

Project Location:

County

Hennepin City

Wayzata, Orono, Mound, Minnetrista, Excelsior, Shorewood, Greenwood

Lake Minnetonka Area Regional Interceptor Improvements Project Environmental Assessment Wayzata, Orono, Mound, Minnetrista, Excelsior, Worksheet Shorewood and Greenwood, Minnesota 2

The project areas are entirely located within Hennepin County and extend through or along the borders of the following sections: Wayzata/Orono Area T117N, R23W, Section 17 T117N, R22W, Sections 5, 6, 8 L46/L49 Area Description: Along Shadywood Road between Crystal Bay Road and Togo Road and along Crystal Bay Road from Shadywood Road to approximately 200 linear feet (LF) southeast of Shadywood Road. L26 Area Description: Beginning at the intersection of Grove Lane and Edgewood Avenue, along portions of Grove Lane, Barry Avenue, Lake Street, Eastman Lane, McGinty Road, Bushaway Road/County Road 101, and ending before Wayzata/Minnetonka municipal boundary. Mound/Minnetrista Area T117N, R24W, Sections 13, 14, 23, 24, 26, 27, 35 L38 Area Description: Along portions of Commerce Boulevard, the railroad right of way north and west of Langdon Lake, Westedge Boulevard/County Road 44, ending near intersection of County Road 44 and Shady Lane. L39/L40 Area Description: Along Manchester Road, and Bradford Lane to intersection with Wilshire Boulevard. Excelsior/Shorewood/Greenwood Area T116H, R23W, Section 6 T117N, R23W, Sections 25, 26, 31, 34, 35, 36 L21 Area Description: Near Lake Virginia along portions of West 62nd Street. Excelsior Area Description: Beginning near Galpin Lake at Highway 7 and Water Street, along portions of Water Street, College Avenue, William Street, Oak Street, Beehrle Street, George Street, Morse Avenue, Excelsior Boulevard, Highway 7, Covington Road, and terminating before intersection with Ridge Road. Additionally, there is a segment from the intersection of 3rd Avenue and Christmas Lake Road along portions of Christmas Lake Road to Excelsior Boulevard. Figures, Tables, and Attachments to the EAW:

Figure Number

Title

1 Lake Minnetonka Area Regional Interceptor Improvements Project Location Map 2 Lake Minnetonka Project Areas 3 Wayzata/Orono Area Project Boundaries 4 Mound/Minnetrista Area Project Boundaries 5 Excelsior/Shorewood/Greenwood Area Project Boundaries 6 Wayzata/Orono Area Environmental Site Assessment 7 Mound/Minnetrista Area Environmental Site Assessment 8 Excelsior/Shorewood/Greenwood Area Environmental Site Assessment 9 Wayzata/Orono Area: L26 Environmental Resource Map – Water Resources 10 Wayzata/Orono Area: L46/49 Environmental Resource Map – Water Resources 11 Mound/Minnetrista Environmental Resource Map – Water Resources 12 Excelsior/Shorewood/Greenwood Area Environmental Resource Map – Water Resources 13 Wayzata/Orono Area: L26 Soil Map 14 Wayzata/Orono Area: L46/49 Soil Map

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Figures, Tables, and Attachments to the EAW (continued): Figure Number

Title

15 Mound/Minnetrista Soil Map 16 Excelsior/Shorewood/Greenwood Soil Map 17 Wayzata/Orono Area: L26 Environmental Resource Map – Cultural Resources 18 Wayzata/Orono Area: L46/49 Environmental Resource Map – Cultural Resources 19 Mound/Minnetrista Environmental Resource Map – Cultural Resources 20 Mound/Minnetrista Area New Interceptor Parks Impacts 21 Excelsior/Shorewood/Greenwood Area Environmental Resource Map – Cultural Resources

Attachment Attachment 1 (Wayzata/Orono and Mound/Minnetrista Areas): Minnesota Department of Natural

Resources (DNR) National Heritage and Nongame Research Program (NHNRP) letter dated May 30, 2006, and e-mail dated October 24, 2006

Attachment 2 (Excelsior/Shorewood/Greenwood Area): DNR NHNRP letters dated September 22, 2006, and e-mail dated October 24, 2006

Attachment 3 (Wayzata/Orono and Mound/Minnetrista Areas): Minnesota Historical Society State Historic Preservation Office (SHPO) e-mails dated May 10, 2006, and October 19, 2006

Attachment 4 (Excelsior/Shorewood/Greenwood Area): SHPO e-mails dated September 7, 2006, and October 19, 2006

Attachment 5 Summary of Development of Communities in Project Service Area 6. Description:

a. Provide a project summary of 50 words or less to be published in the EQB Monitor.

Metropolitan Council Environmental Services (MCES) proposes to construct new interceptor pipelines, abandon/replace other interceptor pipelines, and construct, upgrade, and remove various lift stations and associated facilities in the cities of Wayzata, Orono, Mound, Minnetrista, Excelsior, Shorewood, and Greenwood in order to increase system capacity and improve system reliability.

b. Give a complete description of the proposed project and related new construction. Attach additional sheets as necessary. Emphasize construction, operation methods and features that will cause physical manipulation of the environment or will produce wastes. Include modifications to existing equipment or industrial processes and significant demolition, removal or remodeling of existing structures. Indicate the timing and duration of construction activities. Wayzata/Orono Area This portion of the overall project includes lift station replacement, improvement or relocation, and forcemain rehabilitation/replacement/construction in the cities of Wayzata and Orono. The L26 Area improvements are located entirely within the city of Wayzata, and the L46/L49 Area improvements are located in Orono (see Figure 3). Details of what is proposed in each of these areas are outlined below. I. L26 Area Improvements

The proposed L26 Area improvements include the replacement and/or relocation of lift station L26, replacement or rehabilitation of interceptor 7018-2, and construction of a second forcemain that parallels 7018-2 alignment.


A. Lift Station L26 Improvements

Lift station L26 will be replaced and upgraded at the existing site to meet future design flows. The facility footprint (located entirely within property owned by MCES), including wet well capacity, will be designed for ultimate flows of 24 million gallons per day (mgd). The pumping facilities will be designed for the 2030 projected flow of 18 mgd. The facility will include odor control and back-up power.

B. Forcemain 7018-2 Improvements Existing forcemain 7018-2 (shown in Figure 3) will be reused. The forcemain’s condition and

rehabilitation needs will be determined through a condition assessment. A new forcemain approximately 12,500 feet long roughly parallel to the existing forcemain will be constructed from lift station L26 to the northern edge of the Gray’s Bay Bridge. This new forcemain will connect to the existing manifold at the channel crossing. The proposed forcemain will be constructed in public right-of-way or utilize the existing Burlington Northern Santa Fe (BNSF) Railroad right-of-way.

II. L46/L49 Area Improvements

The proposed L46/L49 Area improvements include the consolidation of lift stations L46 and L49, and replacing a portion of the existing forcemain (8567) with a gravity pipeline. Because of the distance between the L26 project area and the L46/L49 project area, construction of these projects may not be performed concurrently, as this would not necessarily minimize project-related disturbances.

A. Lift Stations L46/L49

Lift stations L46 and L49 will be consolidated into a single pumping station on a site along Shadywood Road/County Road 19 adjacent to the future Dakota Trail. Gravity pipelines will be constructed from existing lift stations L46 and L49 to the new, consolidated lift station.

B. Forcemain 8567 Forcemain 8567 will be replaced by a 20 foot deep gravity line from the new, consolidated lift

station to the intersection of Shadywood Road and Togo Road where it will tie into an existing gravity pipeline.

Mound/Minnetrista Area This portion of the overall project includes consolidating two lift stations and upgrading a third lift station in Mound, and constructing new gravity and forcemain interceptor pipes in Mound and Minnetrista. This portion of the project is split into two work areas, referred to as the L38 Area and the L39/L40 Area (see Figure 4). The L38 Area includes the municipalities of Mound and Minnetrista; the L39/L40 Area is located entirely in Mound. Between these two work areas, existing interceptors will remain in place and serve as the connection between proposed improvements. I. L39/L40 Area Improvements

Existing lift stations L39 and L40 will be replaced with a new, combined lift station. Additionally, a portion of interceptor 6-MO-651 will be replaced. This alternative is shown in Figure 4 and discussed in greater detail below.


A. Lift Stations L39 and 40 Existing lift stations L39 and L40 will be replaced with a new, combined lift station. The new lift station site is proposed in the vicinity of Bradford Lane and Richmond Road. The lift station wet well will be sized for 2050 flows. The proposed combined lift station pumping capacity will be designed to handle a 2030 peak wet weather flow of 1,400 gallons per minute (gpm). Odor control and a backup generator will be provided.

B. Gravity and Forcemains 6-MO-650 and 651

New 12-inch gravity pipes will be constructed to convey flow from the abandoned L40 and L39 lift stations to the new, combined lift station. From there, two new 12-inch forcemains will convey flow to the existing double barrel 8-inch forcemain near the existing L39 lift station. Existing interceptors (6-MO-651 and 6-MO-650) will then convey flow through Mound toward the L38 Area.

II. L38 Area Improvements

Proposed improvements in the L38 Area consist of abandoning the existing interim L25 lift station and installing a new gravity pipe to convey flow to existing lift station L38, upgrading lift station L38 on the existing site, and constructing a new forcemain roughly parallel to the existing forcemain from L38 southward along County Road 44 to a point just north of Highway 7 in Minnetrista where it will connect with an existing gravity interceptor.

A. Gravity and Forcemains 6-MO-650 and 7021

Interim lift station L25 will be abandoned (see the “Construction Methods and Timing for all Projects” section below for a discussion of abandonment of facilities). A new 36-inch gravity pipe, connecting to the existing gravity interceptor upstream of L25, will convey flow along the north side of Langdon Lake to lift station L38. The new pipe will use the same alignment as existing interceptor 6-MO-650. A new 24-inch forcemain will be installed starting at L38 and parallel to the existing forcemain 7021 for approximately 15,400 feet until it empties into existing interceptor 7021 at a point in Lake Minnetonka Regional Park in Minnetrista. The existing forcemain from L38 (interceptor 7021) will be inspected by MCES and rehabilitation needs, if any, will be defined.

B. L38

Upgrades to lift station L38 include providing pump capacity of 6,800 gpm to handle the projected 2030 peak flow and wet well capacity for the 2050 peak flow. The upgraded L38 will pump into the new and the existing 24-inch forcemains. The lift station will include odor control and a backup generator.

A new maintenance facility will be constructed at lift station L38. A maintenance facility exists at this location; however, the building does not provide adequate space for maintenance demands. The proposed facility would include space for items such as an office, locker room, and several service bays. The area required for the facility is approximately 50 by 100 feet.

Excelsior/Shorewood/Greenwood Area This portion of the overall project, shown on Fig. 5, includes the L21 Area Improvements, located entirely in the city of Shorewood (near the Carver/Hennepin County line, next to Victoria); and the Excelsior Area Improvements, located in the Cities of Excelsior, Shorewood and Greenwood. Details of what is proposed in each of these areas are outlined below.


I. L21 Area Improvements

The proposed L21 Area improvements include upgrading lift station L21 and adding a parallel forcemain to 7017.

A. Lift Station L21

Lift station L21, located in the city of Shorewood at the end of Virginia Lake Drive, is proposed to be upgraded at its existing site to accommodate the future design flow of 35 mgd. L21 was designed to pump flow south toward Chanhassen via interceptor 8253-327 or east toward Excelsior via interceptor 7017. The upgraded lift station will maintain the ability to pump in either of these directions. The upgraded lift station will include odor control and a backup generator. The upgraded facility footprint, estimated to be 40 by 55 feet, will be located entirely within property owned by MCES.

B. Interceptor 7017

An additional 800 feet of parallel forcemain capacity will be constructed between lift station L21 and the gravity interceptor that conveys flow to Excelsior (interceptor 7017). This additional forcemain is needed to accommodate the projected future flows.

II. Excelsior Area Improvements

Excelsior Area improvements include modifications to lift stations L19, L20, L18 and L47, and associated gravity interceptors and forcemains (7017, 7017-2, and 7017-3).

A. Lift Station L19

Lift station L19, located in the city of Excelsior at the southeast corner of Smithtown Road and Beehrle Avenue, adjacent to the city of Excelsior Public Works yard (see Figure 5), will be upgraded at its existing location to accommodate the 2030 projected future flow of 10.4 mgd. The upgraded facility’s anticipated footprint will be located entirely on property owned by the city of Excelsior. The lift station wet well will be sized for the projected 2050 flow of 20 mgd. The new lift station will include odor control and a backup generator.

B. Lift Station L20

Lift station L20, located in the city of Shorewood on the southeast corner of Highway 7 and Galpin Lake Road on the shore of Galpin Lake (see Fig. 5), will be eliminated. Flows from L20 will be conveyed to an upgraded lift station L19 (see description for L19 above, and Interceptor 7017-2 below).

C. Lift Station L18

Lift station L18, located in the city of Shorewood on the northern corner of Christmas Lake Road and 3rd Avenue (see Figure 5), will be replaced at the existing site with pump capacity of 1.1 mgd and wet well capacity designed for 1.4 mgd. The footprint of the proposed lift station will be approximately 20 x 30 feet. The lift station will include space for odor control and a backup generator.

D. Lift Station L47

Lift station L47 will be upgraded at the existing site with pump capacity for 2030 flows. The existing wet well is large enough to accommodate 2050 flows. Improvements will also include odor control and a backup generator.


E. Lift Station L19 Forcemain 7017

A new 24-inch forcemain roughly parallel to existing forcemain 7017 will be installed starting from L19 and continuing through Excelsior and Greenwood, crossing under Highway 7 into eastern Shorewood. The new forcemain generally will follow the existing forcemain, reconnecting to an existing gravity interceptor underneath Covington Road (see Figure 5). Construction of the segment of forcemain in Excelsior Boulevard is planned to be coordinated with reconstruction of Excelsior Boulevard.

F. Lift Station L20 Gravity Interceptor 7017-2

Flows from abandoned L20 will be routed through a new gravity interceptor to L19 (see Figure 5). The interceptor will extend across Highway 7 from Chaska Road and involve roughly 3,500 feet of 12-inch gravity interceptor connecting to L19 and 750 feet of new 12-inch gravity sewer to convey flow from the local sewer connection currently discharging at L20. The shorter segment of gravity pipe would become an extension of the Shorewood local sewer. It is anticipated that most of the new gravity interceptor will be installed by open cut construction with the segment under Highway 7 possibly tunneling.

G. Lift Station L18 Forcemain 7017-3

The existing interceptor and forcemain 7017-3 conveys flows through L18 in Shorewood and manifolds into forcemain 7017 north of Highway 7. Improvements to 7017-3 include replacing it with a new forcemain. The interceptor segment crossing under Highway 7 was replaced in 2002 and will be maintained if possible. From L18, a new 8-inch forcemain would replace the existing main and a parallel forcemain would be installed for additional capacity.

Construction Methods and Timing for all Projects The following paragraphs provide general information about construction methods and timing. More detailed information about issues such as discharge of dewatering water is covered in subsequent sections. Construction of the new lift stations and interceptors will potentially involve activities such as excavation, tunneling, temporary storage of excavated material, backfilling, compacting, grading, re-vegetation, and dewatering. Equipment to be used will include standard construction machinery, such as trucks, backhoes, graders, compactors, bobcats, cranes, loaders, compressors, and dewatering pumps. Construction of the project is currently anticipated to occur between 2009 and 2012, with exact timing yet to be determined and dependent on design, funding, and cooperative efforts with affected stakeholders, most notably Hennepin County as it relates to reconstruction of County Road 101, and the city of Excelsior as it relates to reconstruction of Excelsior Boulevard. In order to minimize construction impacts, MCES intends to install the new forcemain interceptor concurrently with these projects. MCES plans to use open trench construction methods for interceptors and anticipates this method for most of the proposed interceptor construction. In some cases, a form of tunneling would used – for instance, under the water crossing at County Road 44 between Halsted Bay and Priest Bay – where permitting or physical constraints will require alternative methods. Abandoned lift stations may be left in place or removed, depending upon the site-specific circumstances. The decision to remove or abandon facilities in place will depend on such site conditions as proximity to water or other natural features, potential impact to roads and design requirements for new facilities. For example, when lift station L20 in Excelsior is taken out of service, some or all of the facility may be abandoned in place because the lift station is very close to Galpin Lake Road and Galpin Lake and complete removal may


undermine the road or do more harm to the lake than abandonment in place. Materials will be disposed of in accordance with applicable state and local rules. Structures abandoned in place will be cleaned and left in a condition that is consistent with applicable regulations.

c. Explain the project purpose; if the project will be carried out by a governmental unit, explain the need for the project and identify its beneficiaries. The proposed Lake Minnetonka Area Interceptor Improvements are needed to convey future wastewater flow from communities in the Lake Minnetonka area and to improve system reliability. In some cases, construction of the proposed improvements will coordinate with other local infrastructure improvements to minimize disruption to the surrounding community. Beneficiaries include residents and businesses in parts of Chanhassen, Excelsior, Greenfield, Greenwood, Independence, Laketown Township, Long Lake, Maple Plain, Medina, Minnetonka Beach, Minnetrista, Mound, Orono, Plymouth, Saint Bonifacius, Shorewood, Spring Park, Tonka Bay, Victoria, Waconia, and Wayzata.

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.

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) Approximately 63 or Length (miles) Approximately 10

Wayzata/Orono Area Approximately 16 acres; approximately 13,500 feet long

Mound/Minnetrista Area Approximately 25 acres, approximately 21,000 feet long

Excelsior/Shorewood/Greenwood Area Approximately 22 acres; approximately 18,500 feet long

Number of Residential Units:

Unattached

N/A

Attached

N/A

Maximum Units Per Building:

N/A

Commercial/Industrial/Institutional Building Area (gross floor space):

total square feet

N/A

Indicate area of specific uses (in square feet):

Office N/A Manufacturing N/A Retail N/A Other Industrial N/A Warehouse N/A Institutional N/A Light Industrial N/A Agricultural N/A Other Commercial (specify) N/A Building height N/A If over 2 stories, compare to heights of nearby buildings N/A


8. Permits and approvals required. List all known local, state and federal permits, approvals and

financial assistance for the project. Include modifications of any existing permits, governmental review of plans, and all direct and indirect forms of public financial assistance including bond guarantees, Tax Increment Financing and infrastructure.

Unit of Government Type of Application Status U.S. Army Corps of Engineers Minnesota Local/State/Federal

Application Forms for Water/Wetland Project (for Clean Water Act Section 404 Permit, including Section 401 water quality certification by MPCA)

Application to be submitted

MPCA Facility Plan Approval (PFA Loan Projects)

Preliminary approval received; final approval pending completion of Environmental Review

MPCA Review and Approval of Construction Plans and Specifications


MPCA Sewer Extension Permit Application to be submitted MPCA NPDES/SDS General Permit for

Discharge of Stormwater during Construction Activities (Construction Stormwater Permit)


MPCA Aboveground and Underground Storage Tank Permits

Applications to be submitted if necessary

MPCA NPDES/SDS Dredged Material Management Permit

Application to be submitted if necessary

MPCA Air Quality Permit (for backup generators)

Application to be submitted if necessary

DNR Minnesota Local/State/Federal Application Forms for Water/Wetland Project (for DNR Public Waters Work Permit)


DNR General Permit 97-005 for Temporary Water Appropriations, if needed

Application to be submitted (if more than 10,000 gallons per day or 1 million gallons per year of water is appropriated)

DNR Utility Crossing License Application to be submitted Minnesota Department of Health Water Well Permit Application to be submitted

(if dewatering wells are necessary)

Hennepin County Permit for Utility Construction on County Road Right-of-Way


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Unit of Government Type of Application Status

City of Minnetrista Application for Minnesota Wetland Conservation Act Certificate of No Loss or Exemption


City of Minnetrista Wetland Protection Permit (Rule D) Application to be submitted City of Mound Application for Minnesota Wetland

Conservation Act Certificate of No Loss or Exemption


City of Wayzata Application for Minnesota Wetland Conservation Act Certificate of No Loss or Exemption


City of Orono Application for Minnesota Wetland Conservation Act Certificate of No Loss or Exemption


City of Orono Grading/Erosion Control Permit Application to be submitted City of Orono Stormwater Management Permit Application to be submitted City of Excelsior Application for Minnesota Wetland

Conservation Act Certificate of No Loss or Exemption


City of Shorewood Application for Minnesota Wetland Conservation Act Certificate of No Loss or Exemption


City of Shorewood Grading/Erosion Control Permit Application to be submitted City of Shorewood Stormwater Management Permit Application to be submitted Minnehaha Creek Watershed

District Grading/Erosion Control and Stormwater Management Permit


Minnehaha Creek Watershed District

Wetland Protection Permit (Rule D) Application to be submitted

Minnehaha Creek Watershed District

Waterbody Crossing (Rule G) Permit Application to be submitted

Although the project is entirely located within Hennepin County, coordination with Carver County and the city of Victoria may be necessary due to their close proximity to the project site. Coordination with Minnehaha Creek Watershed District should cover applicable permits for the city of Greenwood.

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. General For each of the project areas, MCES has conducted an Environmental Site Assessment (ESA) to evaluate the potential for encountering contamination during construction of the project. The results of this study are represented in Figures 6, 7, and 8, which show all of the properties identified as having contamination or potential for contamination. A site’s potential to impact the project corridor (low, medium, or high), is based on an evaluation of the type and quantity of material present, the status of any release of that material, and the property’s proximity to the corridor.


For all project areas, although encountering soil and ground-water contamination during installation of the proposed improvements is not anticipated, it may occur. MCES has developed a protocol for handling contaminated soil consistent with MPCA guidelines. In addition, should contaminated ground water be encountered, MCES would arrange for discharge of this ground water to its sanitary sewer for subsequent treatment at the Blue Lake Wastewater Treatment Plant (WWTP).

For all project areas, MCES will perform additional investigation at or near the sites determined to have a high potential to impact the corridor. Soil and/or ground-water samples will be collected to determine if known or potential contamination these sites will impact construction of the improvements. If contamination is encountered during the boring investigation, it will be reported immediately to the Minnesota Duty Officer. MCES will work with MPCA staff in the appropriate program(s) to determine what additional steps will need to be taken, before and/or during construction, to address the contamination. Appropriate MPCA staff would likely be from the Petroleum Remediation Program, Petroleum Brownfields Program and/or the Voluntary Investigation and Cleanup Program. Steps to address contamination may include additional sampling and proper handling and disposal of contaminated soil and/or ground water.

Wayzata/Orono Area Current land use within the Wayzata/Orono project area consists primarily of state or county highway, city street, and railroad right-of-way. Land uses in close proximity to the project area include residential, commercial (downtown Wayzata), institutional (for example, existing MCES facilities or city of Wayzata properties) and waterbodies. As can be seen in Figure 6, there are no properties in the Wayzata/Orono area identified as having a “high” potential for impact in the project corridor. In general, however, it is recognized that the land use history of Wayzata, especially within the railroad corridor, is indicative of a greater potential for contamination to be encountered. Mound/Minnetrista Area Current land use within the Mound/Minnetrista project area is primarily composed of county highway, city street, and abandoned railroad right-of-way; some parkland (Lake Minnetonka Regional Park and the city of Mound’s Swenson Park) is also present. Other land uses in close proximity to the project area include single-family residential, institutional, open space, commercial, and surface water. The results of the ESA for the Mound/Minnetrista area project corridors are represented in Figure 7. As can be seen, there are no properties identified as having a “High” potential for impact to the project corridor. The former sewage treatment pond located at L38 will be properly closed in accordance with a Closure Plan, to be developed and implemented in accordance with established MPCA guidelines and applicable state rules. The Closure Plan will contain an implementation schedule and detailed plans for closure.

While the proposed project is not in the vicinity of the downtown area of Mound, several properties in downtown Mound have been identified as having soil contamination or are under investigation. Because many of the properties are under investigation, the extent of soil contamination in the study area is uncertain. Additionally, unknown spills of hazardous materials could have occurred along the railroad that parallels the sewer for much of its length.


One Superfund site has been identified in downtown Mound (the Former Tonka Main Plant Site) and was added to the state Superfund list in 1985. Two underground chemical plumes extend from the site: a more extensive “north plume” (for which a treatment plan is being implemented) and a “west plume.” The west plume migrates to the southwest of the plant site and appears to be intercepted by the MCES interceptor beneath Shoreline Boulevard. A 1995 investigation of the west plume by the MPCA confirmed this situation and determined that the west plume does not affect human health or the environment. This project proposes maintaining use of the existing interceptor pipes in the vicinity of the Superfund site. As such, no construction is planned in this area as part of this project. Excelsior/Shorewood/Greenwood Area Current land use within the project corridor in this area is primarily composed of state or county highway and city street right-of-way. Land uses in close proximity to the project area include residential, commercial (downtown Excelsior), institutional, and surface water. The results of the ESA for the Excelsior/Shorewood/Greenwood area are represented in Figure 8. As can be seen, there are five properties identified as having a “High” potential for impact to the project corridor. Soil and ground-water contamination could be encountered during installation of the proposed sewers. MCES will work with the MPCA as described above to have an approved plan in place for handling any contaminated soil or ground water that is encountered. On the basis of this requirement, in addition to design planning, environmental impacts from this activity are not expected.

10. Cover Types. Estimate the acreage of the site with each of the following cover types before and after development: The before and after acreage for the cover types were calculated using a 25-foot buffer on either side of the proposed alignment, as well as including acreage for the lift stations.

Wayzata/Orono Area

L46/L49 Area in Wayzata

Cover Type Acreage Before Acreage After

Types 1-8 wetlands 0.0 0.0

Wooded/forest 0.0 0.0

Brush/grassland 0.0 0.0

Cropland 0.0 0.0

Lawn/landscaping 0.0 0.0

Impervious Surfaces (Highway/Street)

0.2 0.2

Rail/Trail Bed 0.0 0.0

TOTAL: 0.2 0.2


L26 Area in Orono





Cropland 0.0 0.0



9.2

9.2


TOTAL: 15.8 15.8

Mound/Minnetrista Area

Expansion of L38 and the consolidation of L39 and L40





Cropland 0.0 0.0


Impervious Surfaces 0.0 0.1

Highway/Street 17.6 17.6


TOTAL: 25 25


Excelsior/Shorewood/Greenwood Area

Shorewood L21 Area (West)





Cropland 0.0 0.0



0.9 0.9


TOTAL: 0.9 0.9

Excelsior Area (East)





Cropland 0.0 0.0



19.0 19.0


TOTAL: 21.2 21.15

The estimates of wetland extent and wetland impacts in the project area are based on the National Wetlands Inventory (NWI). The NWI was a remote sensing effort completed by the U.S. Fish and Wildlife Service in the 1980s based on aerial photography review. Typically, the NWI provides a reasonable estimate of wetland locations for planning purposes. A NWI-mapping review and windshield survey of the area identified wetlands adjacent to L18. Additional wetland delineation around L18 will be necessary to determine how to accomplish the facility expansion without impacting the wetlands at that location. The proposer intends to expand L18 without affecting adjacent wetlands.


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. Wildlife present in the project area are those species that have adapted to a disturbed residential, urbanized landscape, and are likely to include white-tailed deer, raccoon, skunk, fox, squirrel, chipmunk, rabbit, opossum, bat, mice, and other small rodents. Common songbird and other avian species in urban land within the project area include English sparrows, starlings, brown-headed cowbirds, grackles, Eastern kingbirds, Eastern bluebirds, black crows, red-tailed hawks, and mourning doves. Based on DNR fish netting data, common fish species within the project area are bluegill, pumpkinseed sunfish, yellow bullhead, northern pike, walleye, yellow perch, and black crappie. Short-term impacts on wildlife will include the disruptive effects of construction, including excavation, stockpiling of soils and materials, noise, limited erosion and sedimentation, and vehicle movement. The project itself will not permanently displace wildlife, which is expected to return to the corridor after construction and restoration activities cease. However, urban development enabled by the sanitary sewer line may cause a shift in the species present. Species less tolerant of urban development may be permanently displaced. Limited impacts to waterbodies and associated aquatic species are expected, with some potential for disturbance during construction along the north side of Langdon Lake. Several best management practices (BMPs), such as silt fencing and rapid re-vegetation, will be implemented to protect these waterbodies from erosion or other physical impacts that may affect wildlife.

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: ERDB20060899 Describe measures to minimize or avoid adverse impacts.

The DNR NHNRP was contacted regarding the potential presence of threatened or endangered species, as well as other rare or sensitive biological resources in the vicinity of all portions of the overall project. Following is a summary of the responses received for the various areas. See Attachments 1 and 2 for additional detail. According to the response received for the Mound/Minnetrista project area, there are known occurrences of state (endangered or threatened) species, rare plant communities, or other sensitive ecological resources such as native prairie habitat, colonial water bird nesting colonies, or regionally rare plant communities on or near the project corridor.


Two special concern fish species, the Least Darter (Etheostoma micropeca) and the Pugnose Shiner (Notropis anogenus) have been documented in Lake Minnetonka in the vicinity of the Mound and Wayzata project areas. According to the Minnesota DNR, “As these species are intolerant of environmental degradation, especially turbidity and siltation, it is imperative that stringent erosion and sedimentation control practices be implemented and maintained in these areas.” Blanding’s Turtle is the only known rare specie known to have occurred in the vicinity of the Excelsior/Shorewood/Greenwood project area. The DNR recommends that all below-ground utility construction sites should be returned to original grade to avoid trapping the turtles in trenches. The Hardscrabble Woods Area is a documented native plant community in the L38 Area. Located in Minnetrista, the Hardscrabble Woods is a known Maple-Basswood Forest that is under conservation easement as a high quality plant community. The interceptor in the L38 area utilizes the County Road 44 right-of-way and entirely avoids the Hardscrabble Woods. The DNR’s response also indicated that there are several sites within the Mound area that have been identified as Regionally Significant Ecological Areas (RSEA). Review of the Minnesota County Biological Survey Map, prepared by the DNR, shows that none of these areas are in close proximity to the L38 or the L39/L40 Areas. As described above, BMPs will be implemented to minimize adverse impacts to wildlife and plant species along the construction corridors. To the extent feasible, original landscape grades and vegetative characteristics will be restored or promoted after construction.

12. Physical Impacts on Water Resources. Will the project involve the physical or hydrologic alteration

(dredging, filling, stream diversion, outfall structure, diking, and impoundment) of any surface waters such as a lake, pond, wetland, stream or drainage ditch? Yes No If yes, identify water resource affected. Describe alternatives considered and proposed mitigation measures to minimize impacts. Give the DNR Protected Waters Inventory (PWI) number(s) if the water resources affected are on the PWI. If wetland impacts occur in completing the project, MCES will follow “wetland sequencing” and established wetland permitting procedures in compliance with state and federal regulations. Minn. R. 8420.0122, subp. 6a provides an exemption from wetland replacement for utilities/public works project, such as this sanitary sewer interceptor project. This exempts work done underground such as for interceptors; however, lift stations are not exempt. MCES will coordinate with appropriate cities and watershed districts in the design and permitting of the projects. Wayzata/Orono Area Potential for physical impacts on water resources in the L26 and the L46/L49 Areas is limited because of the reuse of railroad and roadway corridors. This is especially the case in the L26 Area given that there are plans to time interceptor construction within the time frame of Hennepin County’s reconstruction of County Road 101. However, given the proximity of this project to Lake Minnetonka, a discussion of the potential for impacts and measures to avoid impacts is provided below.

Wetlands Preliminary review of wetlands in the study area (by combination of NWI mapping and “windshield” field verification) indicate that wetland impacts may occur in the vicinity of Grays Bay (see Figure 9). A detailed wetland delineation needs to be completed to assess potential wetland impacts accurately. If


wetland impacts cannot be avoided, MCES will follow wetland sequencing and established wetland permitting procedures in compliance with state and federal regulations. MCES will coordinate with the city of Wayzata and Minnehaha Creek Watershed District and other regulatory agencies in the planning and permitting of this project. For the County Road 101 portion of the project, MCES will also be in coordination with Hennepin County to confirm the extent to which the footprint of this proposed project is within the impact footprint of County Road 101 improvements. No wetland impacts are anticipated in the upgrade of lift station L26 or the relocated lift station L46 and L49 (see Figure 10). DNR Public Waters Figures 9 and 10 show the water bodies in the project area that are included on the Minnesota DNR’s Public Waters Inventory (PWI). Maps produced by the DNR’s PWI are called “Protected Waters and Wetlands Maps.” Protected Waters (also known as “Public Waters”) include lakes, public ditches and water courses. Protected Wetlands (also known as “Public Waters Wetlands”) include Types 3, 4, and 5 wetlands that are 10 or more acres in rural areas and 2.5 acres or more within cities. The following PWI identifiers (with water body names) are in the vicinity of the proposed project:

A soil erosion control plan will be prepared and implemented during construction as required by the NPDES/SDS Construction Stormwater Permit (issued by the MPCA) and Minnehaha Creek Watershed District Rule B. This plan will provide specific measures to be implemented during and after construction as appropriate. The sediment and erosion control plans will provide more detail as to the specific measures and will also address phasing of construction, vehicle tracking of sediment, inspection of erosion control measures, and time frames for implementation. Significant coordination with Hennepin County will be required for implementation of the sediment and erosion control plan with regard to the concurrent reconstruction work planned for the County Road 101 corridor. Dewatering activities along the interceptor corridor are expected (discussed further in Item 13). Discharge from dewatering will be managed to limit the potential for impacts, including the potential use of sediment traps, vegetative buffer strips, or a filter sock to trap sediment and filter the water prior to discharge. If dewatering wells are needed, clean discharge from well point dewatering would be dissipated over adjacent wetland areas located beyond construction limits. Mound/Minnetrista Area Wetlands Interceptor alignment and lift station expansion work in the vicinity of L38 will not involve wetland impacts. However, the remainder of the proposed interceptor alignment in the Mound/Minnetrista Area passes through or near NWI-mapped wetlands. A goal of the proposed L39/L40 Area improvements is to consolidate L39 and L40 into a new lift station at a location that is at a greater distance from water bodies (e.g., Cooks Bay) to reduce risks of spills into water bodies or wetlands. Thus, the overall impact of the improvements on water resources is expected to be positive. The proposed L39/L40 Area interceptor alignment shown in Figure 11 would pass through an

Wayzata/Orono Area PWI Identifier Water Body Name

133P Lake Minnetonka 743W Unnamed Wetland 744W Unnamed Wetland 845W Unnamed Wetland 915W Unnamed Wetland


NWI-mapped wetland complex to the east of Cooks Bay. The proposed lift station in the vicinity of Bradford Lane and Richmond Road may also pass near an NWI-mapped wetland complex east of Bradford Lane. Based on field review, the NWI-mapped wetlands do not accurately reflect the extent of the wetlands in that area. Alternate interceptor alignments and lift station locations will be investigated in the design stage of the project with the goal of avoiding wetland impacts. For example, a potential interceptor alignment along existing road right-of-ways will be further investigated. More detailed wetland delineation will be needed during future design stages to accurately assess alternate alignments and sites, their impacts on wetlands and any mitigation that may be necessary. Depending on the size of the lift station area, potential wetland impacts may be eligible for a de minimis exemption, which allows for some minimal wetland impact without requiring mitigation. In order to be considered eligible for de minimis exemption within Hennepin County, the wetland impact amounts must be less than 2,000 square feet. Also, the wetland in question must be under single ownership and entirely within the project property. Any wetland filling would require certification of wetland replacement from the Minnehaha Creek Watershed District, which administers the WCA for the cities of Mound and Minnetrista. The Minnehaha Creek Watershed District also administers the Wetland Protection Permit (Rule D) for the city of Mound, while the city of Minnetrista administers Rule D independently. Due to the connectivity of on-site wetlands that may require filling to “waters of the United States,” permit approvals will be required from the United States Army Corps of Engineers under Section 404 of the Federal Clean Water Act. Any wetland fill would need to be replaced at a 2 to 1 ration in compliance with the Minnesota WCA. Preferably wetland impacts will be avoided or, if impacts cannot be avoided, existing on-site wetlands would be restored, enhanced, or expanded to produce the required wetland replacement credits. If this is not possible, the wetland replacement ratios may be increased. DNR Public Waters The interceptor alignment proposed for the L38 Project Area passes in close proximity to waters included on the DNR’s PWI. These include Langdon Lake (#182P) and Halsted Bay (Lake Minnetonka, #133P). Both of these water resources are shown on Figure 11.

The former sewage treatment pond located at L38 will be properly closed in accordance with a Closure Plan, to be developed and implemented in accordance with established MPCA guidelines and applicable state rules. The Closure Plan will contain an implementation schedule and detailed plans for closure. The following permits will be necessary for the underground crossing of the connection between Halsted Bay and Priest Bay: a) Minnehaha Creek Watershed District Rule G – Waterbody Crossing Permit; and b) DNR Utility Crossing License. Standard tunneling construction methods are expected to be used in this area and should limit the potential for physical impacts to these water bodies. While no physical alteration of public waters are anticipated, these resources will need to be protected during construction of the interceptor. See Item 14 for additional information on the Langdon Lake area. Excelsior/Shorewood/Greenwood Area Potential for physical impacts on water resources in the Shorewood and Excelsior Areas is limited because of the reuse of roadway corridors. This is especially the case in the Excelsior Area given that there are plans to time a large part of the 7017 interceptor construction within the time frame of the city of Excelsior’s reconstruction of Excelsior Boulevard. For the Excelsior Boulevard portion of the project, MCES will coordinate with the city of Excelsior to confirm the extent to which the footprint of this


proposed project is within the impact footprint of the street improvements. However, given the proximity of this project to several area lakes, including Lake Minnetonka, a discussion of the potential for impacts and measures to avoid impacts is provided below.

Wetlands Preliminary review of NWI-mapped wetlands in the study area indicates that there is little potential for wetland impacts to occur (see Figure 12). The greatest potential for wetland impacts is at Lift Station L18, where proposed improvements may substantially increase the footprint of that facility compared to the existing lift station. In Item 10, a preliminary estimate is shown of approximately 0.05 acres of wetland impact. A detailed wetland delineation needs to be completed to accurately assess wetland boundaries in the study area and to rule out the potential for wetland impacts or more clearly define the potential impact.

Additional wetland delineation around L18 will be necessary to determine how to accomplish the facility expansion without impacting the wetlands at that location. The proposer intends to expand L18 without affecting adjacent wetlands. DNR Public Waters Figure 12 shows the water bodies in the project area that are included on the DNR’s PWI. Some of the wetlands identified by NWI are also identified in the PWI maps for Hennepin County. The following PWI identifiers (with water body name) are in the vicinity of the proposed project:


PWI Identifier Water Body Name 15P Virginia Lake 904W Unnamed Wetland 133P Lake Minnetonka 144P Galpin Lake 137P Christmas Lake 896W Unnamed (College) Wetland 898W Unnamed Wetland 145P Como Lake 884W Unnamed Wetland

A soil erosion control plan will be prepared and implemented during construction as required by the NPDES/SDS Construction Stormwater Permit (issued by the MPCA) and Minnehaha Creek Watershed District Rule B. This plan will provide specific measures to be implemented during and after construction, as appropriate. The sediment and erosion control plans will provide more detail as to the specific measures to be implemented and will also address phasing of construction, vehicle tracking of sediment, inspection of erosion control measures, and time frames for implementation.

Dewatering activities along the interceptor corridor are expected (discussed further in Item 13). Discharge from dewatering will be managed to limit the potential for impacts, including the potential use of sediment traps, vegetative buffer strips, or a filter sock to trap sediment and filter the water prior to discharge. If dewatering wells are needed, clean discharge from well point dewatering would be dissipated over adjacent wetland areas located beyond construction limits.


13. Water Use. Will the project involve installation or abandonment of any water wells, connection to or

changes in any public water supply or appropriation of any ground or surface water (including dewatering)? 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. Given the proximity to several water bodies, ground water is expected to be encountered during construction, potentially requiring dewatering activities. Dewatering wells would be placed by the construction contractor based on the evaluation of dewatering needs. A DNR General Permit 97-0005 for Temporary Water Appropriations will be required if withdrawal exceeds 10,000 gallons per day. Total volume pumped under this permit cannot exceed 50 million gallons, and water appropriations must be completed within one year from the start of pumping. Where dewatering is necessary, the pumped water would be discharged as discussed in Item 12. Dewatering is unlikely to affect the availability of water to existing water wells because wells in the area are completed to depths of greater than 100 feet and are not well connected with shallow ground water. The locations of existing wells are not currently known with sufficient accuracy to verify whether or not the required isolation distance can be maintained. The required setback for wastewater interceptors and lift stations is 50 feet. A field survey will be performed to accurately determine the distances of wells on adjacent properties from the final interceptor alignments and lift stations. If any water supply wells are found within 50 feet of an interceptor alignment or lift station during the construction phase of the project, the required isolation distance will be maintained by abandoning the well in accordance with Minnesota rules administered by the Minnesota Department of Health and constructing a new well 50 feet or more from the interceptor/lift station while maintaining all other required isolation distances. If necessary, trench dams will be incorporated into the project to prevent unintentional draining of wetlands. The position of trench dams would depend on observed ground-water conditions. Perched wetlands will be identified using soil borings. A confining layer of low-permeability soils will be restored to maintain perched conditions.

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. Much of the project area is located near or within the Lake Minnetonka regional floodplain. However, given the nature of the underground interceptors, the proposed project is not expected to permanently affect the floodplain. As required by the Minnehaha Creek Watershed District and the cities of Wayzata, Orono, Mound, and Minnetrista, any construction project must compensate for flood storage volume by providing replacement of flood storage in stormwater treatment and enhancement areas. In the event of the need for fill, floodplain alternation approvals must be coordinated with the Minnehaha Creek Watershed District, the cities, and the DNR prior to work being completed within the flood fringe of the floodplain.


Wayzata/Orono Area Shoreland - In the BNSF railroad corridor through downtown Wayzata, and along County Road 101 at Gray’s Bay, and along Shadywood Road in Orono, all portions of the project are in the vicinity of Lake Minnetonka shoreland, a DNR-protected public water (see Figures 9 and 10). 100-year Floodplain - The proposed interceptor alignment passes through area mapped as within the 100-year floodplain, as shown on Figures 9 and 10. Staff from the Minnehaha Creek Watershed District has confirmed that the Lake Minnetonka regional floodplain falls between elevations 929.4 feet and 931.5 feet. Available ten-foot contour GIS information indicates that area mapped as 100-year floodplain within the L46/L49 Area is approximately 940 feet, meaning that it is not likely that this area is included in the Lake Minnetonka regional floodplain. Therefore, the area mapped as 100-year floodplain on Figure 10 is likely overly presented. It appears that the 100-year floodplain mapping for the L26 Area is accurate. Given the proximity of this part of the project to Lake Minnetonka and Gray’s Bay, some encroachment into the 100-year floodplain is possible. Given the nature of the underground interceptors, however, the proposed project is not expect to permanently affect the floodplain, regardless of whether the project encroaches on the Lake Minnetonka regional floodplain. Mound/Minnetrista Area Shoreland - A portion of the proposed interceptor alignment is within the Langdon Lake shoreland, a DNR-protected public water, in the vicinity of the northernmost part of Interceptor 7021, the westernmost section of 6-MO-650. This includes land within the abandoned railroad tracks north of Langdon Lake in Mound. 100-year Floodplain - The proposed interceptor alignment passes through area mapped as within 100-year floodplain, as shown in Figure 11. Staff from the Minnehaha Creek Watershed District has confirmed that the Lake Minnetonka regional floodplain falls between elevations 929.4 feet and 931.5 feet. Available ten-foot contour GIS information indicate that area mapped as 100-year flood plain within the L39/L40 Area is above 931.5 feet, meaning that this area would not be included in the Lake Minnetonka regional floodplain. Excelsior/Shorewood/Greenwood Area The project improvements are located close to several waterbodies, including Virginia Lake, Galpin Lake, and Lake Minnetonka (see Figure 12). However, the proposed work does not involve any of the water-related land use management districts described above. The closest locations for potential impact to any of these districts are at Lift Stations L21 and L20. In the case of L21 (an upgrade of the lift station), the work is entirely within property owned by MCES and is located away from the shoreline of Virginia Lake. At L20 (an abandonment of the lift station), the work needed to be done there is minimal, since the lift station will not be used any longer. For both lift stations, any construction or removal of equipment activities would involve standard erosion control and related BMPs to reduce the potential for impact to these water bodies.

15. Water Surface Use. Will the project change the number or type of watercraft on any water body? Yes No

If yes, indicate the current and projected watercraft usage and discuss any potential overcrowding or conflicts with other uses.


16. Erosion and Sedimentation. Give the acreage to be graded or excavated and the cubic yards of soil to be moved: 9.7 acres; 157,040 cubic yards.

These estimates are based on 53,000 linear feet (lf) of new pipe (21,000 lf in Mound Area; 13,500 lf in Wayzata Area; 18,500 lf in Excelsior Area); an average trench depth of 10 feet; and an average trench width of 8 feet. (Note: the anticipated cubic yards of grading figure is a preliminary estimate that is subject to change.)

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. Wayzata/Orono Area Several soils mapped by the Soil Survey of Hennepin County as Highly Erodible and/or Steeply Sloping are present in or near the alignment of the sewer line. Highly Erodible and Steeply Sloping soils are depicted on Figures 13 and 14, and summarized in the table below.

Highly Erodible and Steeply Sloping Soils - Wayzata/Orono Area Mapping Unit Soil Series Special Considerations 1 L2D Malardi-Hawick complex, 12 to 18 percent slopes Steeply Sloping L22C2 Lester loam, morainic, 6 to 12 percent slopes,

eroded Steeply Sloping, Highly Erodible

L22D2 Lester loam, morainic, 12 to 18 percent slopes, eroded

Steeply Sloping, Highly Erodible

L70C2 Lester-Malardi complex, 6 to 12 percent slopes, eroded


1 For purposes of this EAW, “Steeply Sloping” is defined as a soil series with a “C” slope or higher, i.e. 6% slopes or greater. The designation of “Highly Erodible” is per the Hennepin County Soil Survey, i.e. The Soils Data Mart.

Several soil series near the alignment of the L26 and L46/L49 Area improvements are both Steeply Sloping and Highly Erodible. Several segments of the proposed improvements are near water bodies or cross water bodies. Specific areas where the combination of Highly Erodible and Steeply Sloping soils are present are summarized in the table below, and shown in Figures 13 and 14.

Sensitive Areas with Respect to Highly Erodible and Steeply Sloping Soils – Wayzata/Orono Area Sewer Line Segment Project Area Soil Characteristics Western Project Limit L26 Area Steeply Sloping, Highly Erodible, within

150 feet of Lake Minnetonka Approximately 300 feet east of the L26 Area’s western limit

L26 Area Adjacent to shore of Lake Minnetonka

Approximately 1,300 feet north of L26 Area’s eastern limit

L26 Area Steeply Sloping soil, adjacent to Lake Minnetonka

Approximately 200 feet north of L49

L46/L49 Area Steeply Sloping, Highly Erodible, within 150 feet of Lake Minnetonka


Mound/Minnetrista Area Several soils mapped by the Soil Survey of Hennepin County as Highly Erodible and/or Steeply Sloping are present in or near the alignment of the sewer line. Highly Erodible and Steeply Sloping soils are depicted on Figure 15 and summarized in the table below.

Highly Erodible and Steeply Sloping Soils - Mound/Minnetrista Area Mapping Unit Soil Series Special Considerations 1 L2C Malardi-Hawick complex, 6 to 12 percent slopes Steeply Sloping L2D Malardi-Hawick complex, 12 to 18 percent slopes Steeply Sloping L2E Malardi-Hawick complex, 18 to 35 percent slopes Steeply Sloping L3C Rasset sandy loam, 6 to 12 percent slopes Steeply Sloping L22C2 Lester loam, morainic, 6 to 12 percent slopes,


L22D2 Lester loam, morainic, 12 to 18 percent slopes, eroded


L22E Lester loam, morainic, 18 to 25 percent slopes Steeply Sloping L22F Lester loam, morainic, 25 to 35 percent slopes Steeply Sloping L41C2 Lester-Kilkenny complex, 6 to 12 percent slopes,


L41D2 Lester-Kilkenny complex, 12 to 18 percent slopes, eroded


L41E Lester-Kilkenny complex, 18 to 25 percent slopes Steeply Sloping L47C Eden Prairie sandy loam, 6 to 12 percent slopes Steeply Sloping L61C2 Lester-Metea complex, 6 to 12 percent slopes,


L70C2 Lester-Malardi complex, 6 to 12 percent slopes, eroded


L70D2 Lester-Malardi complex, 12 to 18 percent slopes, eroded


L2C Malardi-Hawick complex, 6 to 12 percent slopes Steeply Sloping 1 For purposes of this EAW, “Steeply Sloping” is defined as a soil series with a “C” slope or higher, i.e. 6% slopes or greater. The designation of “Highly Erodible” is per the Hennepin County Soil Survey, i.e. The Soils Data Mart.

Several soil series near the alignment of the Mound Area improvements are both Steeply Sloping and Highly Erodible. Several segments of the Mound Area improvements are near waterbodies or cross water bodies. Specific areas where the combination of Highly Erodible and Steeply Sloping soils are present depicted in Figure 15 and are summarized in the table below.


Sensitive Areas with Respect to Highly Erodible and Steeply Sloping Soils – Mound/Minnetrista

Area Sewer Line Segment Project Area Soil Characteristics East of County Road 44 in Minnetrista (near southern project terminus)

L38 Area Highly Erodible and Steeply Sloping

North of County Road 44 and Lotus Drive Intersection, in Minnetrista

L38 Area Highly Erodible and Steeply Sloping

Along County Road 44 between Halsted Bay and Priests Bay (Lake Minnetonka)

L38 Area Much of alignment on or near soils that are both Highly Erodible, Steeply Sloping, and near the shoreline of Lake Minnetonka.

Along Westedge Boulevard near northeast edge of Halsted Bay (Lake Minnetonka)

L38 Area Some of this segment on or near Highly Erodible and Steeply Sloping soils, and near the shoreline of Lake Minnetonka.

Along eastern and northern side of Langdon Lake

L38 Area The alignment intersects several areas with soils that are Highly Erodible, Steeply Sloping. These areas are greater than 150 feet from the shoreline of Langdon Lake.

East of southern terminus of L39/L40 Area

L39/L40 Area

The alignment intersects a small area with soils that are both Highly Erodible and Steeply Sloping.

Excelsior/Shorewood/Greenwood Area Several soils mapped by the Soil Survey of Hennepin County as Highly Erodible and/or Steeply Sloping are present in or near the alignment of the sewer line. Highly Erodible and Steeply Sloping soils are depicted on Figure 16 and summarized in the table below.

Highly Erodible and Steeply Sloping Soils - Excelsior/Shorewood/Greenwood Area Mapping Unit Soil Series Special Considerations

1 L22C2 Lester loam, morainic, 6 to 12 percent slopes, eroded Steeply Sloping L22D2 Lester loam, morainic, 12 to 18 percent slopes, eroded Steeply Sloping L22E Lester loan, morainic, 18 to 25 percent slopes, eroded Steeply Sloping, Highly

Erodible L41C2 Lester-Kiklenny complex, 6 to 12 percent slopes,

eroded Steeply Sloping

L61C2 Lester-Metea complex, 6 to 12 percent slopes, eroded Steeply Sloping L61E Lester-Metea Complex, 18 to 25 percent slopes Steeply Sloping, Highly

Erodible 1 For purposes of this EAW, “Steeply Sloping” is defined as a soil series with a “C” slope or higher, i.e., six percent slopes or greater. The designation of “Highly Erodible” is per the Hennepin County Soil Survey, i.e., The Soils Data Mart.


Several soil series near the alignment of the Excelsior and Shorewood sewer improvements are both Steeply Sloping and Highly Erodible, and are also near waterbodies. Specific areas where the combination of Highly Erodible and Steeply Sloping soils are present are depicted in Figure 16 and summarized in the table below.

Sensitive Areas with Respect to Highly Erodible and Steeply Sloping Soils – Excelsior/Shorewood/Greenwood Area

Sewer Line Segment Project Area Soil Characteristics 7017 forcemain east of L21 L21 Area Steeply sloping, highly erodible, within

150 feet of Lake Virginia 7017-2 new gravity between abandoned L20 and L19

Excelsior Area Steeply sloping, highly erodible, within 150 feet of Galpin Lake and two public water inventory (PWI) wetlands (see Section 12)

7017 new forcemain through City of Excelsior and into Greenwood and Shorewood

Excelsior Area Steeply sloping, highly erodible

7017-3 forcemain north of L18 Excelsior area Steeply sloping, highly erodible Erosion and Sedimentation Control Measures to be Used During and After Project Construction Generally, the interceptor system improvements in each project area involve temporary impacts associated with construction. Excavated soils would be backfilled around the sewer line. BMPs, including the following, will be used in and near water bodies and where both Highly Erodible and Steeply Sloping soils are present to minimize sedimentation and erosion. • Silt fences. Heavy duty silt fences will be installed downslope from the base of the temporary soil piles

created as a result of sewer excavation. The bottom edge of the silt fence will be buried on the upslope side to a depth of six inches. The silt fence will be supported by steel T-posts spaced a maximum distance of eight feet apart.

• Hydraulic Mulching. Mulch hydrospraying on soil piles will be employed where necessary to reduce erosion potential. This BMP could be used if soil piles must remain for an extended construction period, and also could be used to encourage vegetative growth immediately after re-grading the completed stretch of sewer line.

• Rapid Re-Vegetation. After the construction site is re-graded, rapid re-vegetation can be encouraged with the use of straw mats or with fibrous material disked into the ground. A planted cover of annual rye grass will minimize erosion prior to establishment of more permanent vegetative cover.

The majority of excavated soil will be returned to the construction trench after placement of the pipe. Any excess soil will be disposed of in upland areas where sediment will not impact water resources or other sensitive areas. Soil erosion control practices will be implemented to minimize impacts to lakes and wetlands immediately adjacent to or in the vicinity of the project. BMPs will be utilized. Construction practices will be managed to limit the duration of exposed soil to wind and rain. It is not anticipated that materials will be excavated from below the Ordinary High Water Level (OHWL) of any water bodies. However, if it becomes necessary to excavate materials from below the OHWL, the materials will be tested and handled in accordance with MPCA requirements. The appropriate MPCA Dredged Material Management Permit will be obtained.


Detailed temporary and permanent sediment and erosion control plans must be prepared in accordance with the MPCA NPDES/SDS Construction Stormwater Permit and in consultation with the Minnehaha Creek Watershed District. Erosion control measures will be implemented prior to the start of any construction activities and will remain in place until site stabilization has been achieved. Specific measures 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. Regular inspection will insure that measures implemented remain effective

17. Water Quality – Surface-water Runoff. a. Compare the quantity and quality of site runoff before and after the project. Describe

permanent controls to manage or treat runoff. Describe any storm-water pollution prevention plans. The quantity and quality of site runoff after project completion will be similar to pre-construction conditions. A small amount of new impervious surface will be created from the upgrades of Lift Stations 18, 19, 21, 26, and 38, as well as the rehabilitation of Lift Station 47 and the combination of L39/L40. A small amount of new impervious surface will also be created through the consolidation of L46 and L49; however, existing L46 and L49 will be removed from service and potentially converted back to lawn or landscaped area. Lift Station 20 will be removed from service, creating potential for conversion back to lawn or landscaped area. As discussed previously, the project will require a Construction Stormwater Permit from the MPCA. The Construction Stormwater Permit requires the preparation of a Stormwater Pollution Prevention Plan (SWPPP) designed in accordance with MPCA requirements. The SWPPP includes both temporary and permanent erosion and sediment control plans. The SWPPP will be developed in coordination with the Minnehaha Creek Watershed District. Permanent controls to manage runoff will include restoration of site grade to match existing conditions, and establishing permanent vegetative cover to reduce wind and water erosion effects along the alignment.

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. Construction grading plans and stormwater pollution prevention plans prepared before construction will include management of runoff from construction areas so that sediment-laden water does not impact the quality of these receiving waters.

Wayzata/Orono Area Immediate water bodies associated with the project alignment include Lake Minnetonka’s Gray’s Bay in the L26 Area and Crystal Bay in the L46/L49 Area. Mound/Minnetrista Area Major downstream water bodies associated with the project alignment include Langdon Lake and Cooks Bay of Lake Minnetonka.


Excelsior/Shorewood/Greenwood Area Immediate water bodies associated with the proposed interceptor alignment in Excelsior include Lake Minnetonka’s Excelsior Bay and St. Albans Bay, Galpin Lake, Christmas Lake, and various unnamed lakes and wetlands. Virginia Lake is the only water body in close proximity to the L21 Area in Shorewood.

18. Water Quality – Wastewater. a. Describe sources, composition and quantities of all sanitary, municipal and industrial

wastewater produced or treated at the site. The facilities included in this project will not produce or treat wastewater; rather the facilities will be a conveyance for wastewater. Flow conveyed through the proposed facilities will be normal strength domestic wastewater. Flows from multiple upstream communities are routed through Wayzata and Excelsior, as noted in the table below:

Project Area Flows Tributary to Blue Lake WWTP

Project Area

Projected 2030 Average Daily Flow

mgd

2005 Average Daily Flow

mgd

Additional Average Daily Flow

mgd Wayzata/Orono 8.9 2.0 6.9 Mound/Excelsior Meter 415 7.1 1.8 5.3 Meter 412 13.0 5.5 7.5 Total 29.0 9.3 19.7

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. NA

c. If wastes will be discharged into a publicly owned treatment facility, identify the facility, describe any pretreatment provisions and discuss the facility’s ability to handle the volume and composition of wastes, identifying any improvements necessary. Wastewater will be conveyed by the proposed facilities to the Blue Lake WWTP as part of the Metropolitan Disposal System. The Blue Lake WWTP currently treats approximately 26 mgd and has a design capacity of 38 mgd. Capacity improvements are planned for the Blue Lake WWTP but are not the subject of this EAW.

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. NA


19. Geologic hazards and soil conditions. a. Approximate depth (in feet) to ground water: The following information was taken from the Geologic Atlas – Hennepin County, Minnesota

(University of Minnesota Geological Survey, 1989): Wayzata/Orono Area

Approximate depth to Ground Water(in feet):

Minimum Average

In L46/L49 Area: 0 feet 0 feet

In L26 Area: 0 feet 5 feet Mound/Minnetrista Area


Minimum Average

In L38 Area: 0 feet 35 feet

In L39/L40 Area: 0 feet 10 feet



Minimum Average

In L21 Area: 1.5 feet >6 feet

In Excelsior Area: 2.5 feet >6 feet Approximate depth (in feet) to bedrock:

Approximate depth to Bedrock (in feet):

Minimum Average

Mound Area: 150 feet > 150 feet (up to 500 feet)

Wayzata Area: 51 feet >51 feet Excelsior Area: 51 feet >51 feet


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. Sinkholes, shallow limestone formations or karst conditions have not been identified in the field nor are they identified in the “Geologic Atlas – Hennepin County, Minnesota” (University of Minnesota Geological Survey 1989). It is not anticipated that the proposed sewer improvements will pose an unusual risk to ground-water resources.

b. Describe the soils on the site, giving SCS classifications, if known. Discuss soil granularity and potential for ground-water contamination from wastes or chemicals spread or spilled onto the soils. Discuss any mitigation measures to prevent such contamination. Wayzata/Orono Area The L26 Area near Wayzata Bay is underlain by three bedrock formations: Prairie du Chien dolostone, St. Peter Sandstone and Platteville/Glenwood Formation fine-grained limestone. The L46/L49 Area, along the south edge of Crystal Bay in Orono is underlain by Jordan Sandstone. In the L26 Area, on the east side of Wayzata Bay, the bedrock formation closest to the land surface is Prairie du Chien dolostone. Along the north side of Wayzata Bay, Platteville/Glenwood Formation fine-grained limestone is the formation closest to the land surface. The bedrock formation closest to the land surface at the improvements located in the L46/L49 Area in Orono is Jordan Sandstone. A small area east of Wayzata Bay and north of Gray’s Bay is underlain by Platteville/Glenwood Formation fine-grained limestone at a depth of 51-100 feet below the land surface. All other areas within the Wayzata project area, including the improvements at Orono, are underlain by bedrock at a depth of less than 100 feet below the land surface. Surficial soils are discussed with respect to how quickly water is transmitted through them; sandy soils typically have a high hydraulic conductivity and soils with more fines have a lower hydraulic conductivity. Thus, sandy soils have a greater potential than finer soils to convey contaminants to ground-water resources. Surficial deposits underlying the north side of Wayzata Bay are glacial outwash deposits (sand, loamy sand, and gravel overlain by approximately four feet of wind deposited loess) of the Des Moines Lobe and Grantsburg Sublobe and post glacial organic soil deposits (University of Minnesota Geological Survey, 1989). Surficial deposits underlying the eastern side of Wayzata Bay and the southern side of Crystal Bay (in Orono) are glacial till of the Des Moines Lobe and Grantsburg Sublobe. Specifically, the glacial till is loamy till (mostly loam) and sandy till (loam and sandy loam) on the east side of Wayzata Bay, and loamy till on the south side of Crystal Bay in Orono. The coarser deposits of the Superior Lobe are generally more than 75 feet below the land surface throughout the entire project area and, therefore, will not likely be encountered during excavation. There is a potential for sandy soils to be encountered during excavation in the eastern portion of the project area. If sandy soils are encountered, then clay soil amendments or geotextiles may be appropriate to prevent ground-water contamination.


The digital Soil Survey for Hennepin County (Natural Resources Conservation Service [NRCS], 2006) shows several polygons of organic soils throughout the project area. The alignment intercepts one of these polygons, mapped as L16A – Muskego, Blue Earth, and Houghton soils, ponded, 0-1 percent slopes. This area of organic soil is located approximately 150 feet from the shoreline of the northeastern-most corner of Wayzata Bay (Lake Minnetonka) (see Figures 13 and 14). Organic soils are a concern for two reasons: they are typically unstable for construction purposes, and they are often in contact with the water table. If organic soils are encountered during construction, they may need to be deeply excavated and backfilled with clean stable mineral soils. Geotextiles may be appropriate to prevent contamination of ground water. Mound/Minnetrista Area The Mound sewer improvement area (L39/L40 and L38 Areas) is underlain by three bedrock formations: Jordan sandstone; St. Lawrence and Franconia siltstone, shales, and sandstones; and Prairie du Chien dolostone. Within the project area, the bedrock formation closest to the land surface is Jordan sandstone. Jordan sandstone is closest to the land surface under Halsted Bay (Lake Minnetonka), where it lies approximately 85 feet under the lake surface. The maximum depth of Halsted Bay is 36 feet, thus bedrock lies approximately 49 feet beneath the lake bottom. Bedrock underlying all other areas within the Mound project is greater than 85 feet below the land surface. Surficial deposits underlying the entire Mound project area are glacial till deposits of the Des Moines Lobe and Grantsburg Sublobe (University of Minnesota Geological Survey, 1989). Specifically, the glacial deposits are generally loamy till, i.e., with a mixture of sand, silt, and clay. The Loamy Till becomes thinnest along the east side of Halsted Bay (Lake Minnetonka). The Loamy Till on the east side of Halsted Bay is approximately 20-25 feet thick and is underlain by the sand, loamy sand, grave, cobbles, and boulders of the Superior Lobe. Thus, most sewer improvements in the Mound area will not intercept exceptionally sandy soils and do not pose an unusual risk to ground-water resources. There is a potential for sandy soils to be encountered during excavation on the east side of Halsted Bay. If sandy soils are encountered, then clay soil amendments or geotextiles may be appropriate to prevent ground-water contamination. Excelsior/Shorewood/Greenwood Area The Excelsior sewer improvement area near the Shorewood addition (lift station L21 and interceptor 7017) is underlain by Jordan Sandstone rock formation. Lift station L19 is underlain by the dolostone of the Prairie du Chien Group. East of L19 to the eastern terminus of the Excelsior improvements is underlain by the St. Peter Sandstone rock formation. Bedrock is deeper than 150 feet below the soil surface throughout the entire project area. Surficial deposits underlying the Shorewood addition (L21 and associated portion of interceptor 7017) on the north side of Virginia Lake are loamy glacial till of the Des Moines Lobe and Grantsburg Sublobe and post glacial organic soil deposits (University of Minnesota Geological Survey, 1989). Surficial deposits underlying the eastern portion the Excelsior project (i.e., south of Gideon Bay, Excelsior Bay, and St. Albans Bay east to the eastern project terminus) are sandy glacial till of the Des Moines Lobe and Grantsburg Sublobe. There is a potential for sandy soils to be encountered during excavation in the eastern portion of the project area, i.e., from L19 eastward. If sandy soils are encountered, then clay soil amendments or geotextiles may be appropriate to prevent ground-water contamination.


The digital Soil Survey for Hennepin County (NRCS, 2006) shows several polygons of organic soils near the Excelsior Area sewer improvements; however, the improvements do not intercept any polygons of organic soils. The Surficial Geology map of the Excelsior project area in the “Geologic Atlas – Hennepin County, Minnesota” (University of Minnesota Geological Survey, 1989) shows organic soils to be near, though potentially slightly west of L21 (see Figure 16). If organic soils are encountered during construction, they may need to be deeply excavated and backfilled with clean stable mineral soils. Geotextiles may be appropriate to prevent contamination of ground water.

20. Solid Wastes, Hazardous Wastes, Storage Tanks. a. Describe types, amounts and compositions of solid or hazardous wastes, including solid animal

manure, sludge and ash, produced during construction and operation. Identify method and location of disposal. For projects generating municipal solid waste, indicate if there is a source separation plan; describe how the project will be modified for recycling. If hazardous waste is generated, indicate if there is a hazardous waste minimization plan and routine hazardous waste reduction assessments. Construction activities will generate waste materials such as excess soil, packing materials, and demolition debris. These materials will be disposed of in accordance with applicable state and local rules and regulations. No hazardous waste will be generated during normal construction activities. Any contaminated soils that would be discovered during construction would be reported to the Minnesota Duty Officer and addressed in accordance with MPCA and local regulations.

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 ground water. If the use of toxic or hazardous materials will lead to a regulated waste, discharge or emission, discuss any alternatives considered to minimize or eliminate the waste, discharge or emission. MCES will require its construction contractor to have an established plan in place conforming to MCES’ Spill Reporting Procedure for reporting and handling spills during construction. The aim of the plan is to avoid waste discharges or emissions. During construction, equipment utilizing gasoline, diesel fuel, antifreeze, and oil will be used at the project site. Portable storage tanks of fuel may be temporarily located at the site during construction. Fueling of vehicles and equipment will be conducted away from sensitive areas. Any spill of petroleum product would be cleaned up immediately, and reported to the Minnesota Duty Officer if greater than five gallons. Spills of other materials will also be reported to the Minnesota Duty Officer. Any soils excavated from below the OHWL will be handled in accordance with MPCA’s NPDES/SDS requirements.

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. As discussed above, portable storage tanks of fuel may be temporarily located at the project site during construction. The contractor will be required to follow all applicable local, state, and federal rules for storage and handling of fuels.


The following table lists petroleum storage tanks (underground or aboveground) installed at MCES lift stations in the project area. The petroleum is used as fuel for the backup diesel generators in case of power outage.

Site Tank Number Capacity, gallons Contents L18 124707 AST 1001 525 Diesel Fuel L19 3076 AST 1001 2,000 Diesel Fuel L21 3078 AST 1001 1,700 Diesel Fuel L26 3084 AST 1001 800 Diesel Fuel L38 3080 AST 1001 560 Diesel Fuel L38 3080 AST 1003 265 Used Oil L38 3080 AST 1004 5,000 Bioxide

As described previously, the proposed improvements include installing backup generators at several lift stations. Fuel tanks associated with the backup generators will be registered with the MPCA and installed and operated in accordance with MPCA regulations on secondary containment, leak detection, spill protection, etc. Any leak or spill from a tank will be cleaned up immediately; those that are greater than five gallons will be reported to the Minnesota Duty Officer.

21. Traffic. Parking spaces added: 0 Existing spaces (if project involves expansion): 0 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. Wayzata/Orono Area This project will have no long-term impacts on the regional transportation system. Construction activities on city streets, along with the presence of construction vehicles, will occasionally result in temporary traffic congestion or temporary detours. MCES is coordinating with the city of Wayzata to minimize construction impacts on city right-of-way. The project alignment runs along County Road 16 (Lake Street). MCES is working with Hennepin County to mitigate short-term traffic impacts. The County Road 101 portion of this project will be constructed while Hennepin County is reconstructing the roadway. To the extent the proposed interceptor improvements potentially affect the timing of construction and related detours, the issue will be closely coordinated with Hennepin County. Coordination with Hennepin County with regard to construction of a the new lift station consolidating L46 and L49 will also occur, as the project has potential short-term impacts to traffic on County Road 19 (Shadywood Road).

Mound/Minnetrista Area This project will have no long-term impacts on the regional transportation system. Construction activities on city streets, along with the presence of construction vehicles, will occasionally result in temporary traffic congestion or temporary detours. Hennepin County roads within the proposed project area include the following:


• County Road 44: the proposed forcemain interceptor from the upgraded L38 follows County Road 44

• County Road 110: the proposed gravity Interceptor crosses County Road 110 twice • County Road 125: a portion of proposed L39/L40 Area includes reuse of existing interceptors

running along County Road 125 (Wilshire Boulevard)

Local streets that may be affected by the proposed construction in the L39/40 Area include the following: Brighton Boulevard, Bradford Road, and Devon Lane. As described above, potential alternate routes will be developed in the project’s design stage to avoid or minimize wetlands impacts. Alternate routes would likely involve more construction in the street right-of-way, such as along Leslie Road, rather than in Swenson Park. Construction vehicles will utilize local roads during construction. Impacts to traffic congestion may temporarily occur during this time. North of Langdon Lake, the project alignment exists in the railroad right-of-way extending through areas that would not require road crossings. Construction activities will generally be limited to movement of construction equipment in the work area. Excelsior/Shorewood/Greenwood Area This project will have no long-term impacts on the regional transportation system. Construction activities on city streets, along with the presence of construction vehicles, will occasionally result in temporary traffic congestion or temporary detours. Hennepin County roads within the proposed project area include the following:

• County Road 19: a portion of the proposed gravity interceptor from the abandoned L20 will follow County Road 19 (Oak Street).

• County Road 17: a portion of the proposed forcemain from upgraded L19 will cross County Road 17 (Mill Street).

State of Minnesota roads within the proposed project area include the following:

• Highway 7: the proposed gravity interceptor from the abandoned L20 and the proposed forcemain from upgraded L18 will cross Highway 7; it is anticipated that these portions of the proposed interceptors will be installed by tunneling under the highway, which will minimize transportation impacts.

The remaining work will occur in city right-of-way. Construction of the segment of forcemain in Excelsior Boulevard is planned to be coordinated with reconstruction of Excelsior Boulevard. To the extent the proposed interceptor improvements potentially affect the timing of construction and related detours, the work will be closely coordinated with Hennepin County, the state of Minnesota, and the city of Excelsior.

22. Vehicle-related Air Emissions. Estimate the effect of the project’s traffic generation on air quality, including carbon monoxide levels. Discuss the effect of traffic improvements or other mitigation measures on air quality impacts. Note: If the project involves 500 or more parking spaces, consult EAW Guidelines about whether a detailed air quality analysis is needed. Vehicle emissions associated with the construction of the project will not have a significant effect on air quality.


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. No significant air quality impacts are anticipated. Existing lift stations may currently be limited sources of emissions from backup generators, with the exception of L39 and L40, which do not have generators. Any current air quality impacts are localized and limited to the immediate vicinity of the lift stations. The existing locations are in fairly urbanized portions of Wayzata, Shorewood, and Excelsior and do not have a history of complaints or air quality problems. The elimination of L20 and L46 will improve air quality slightly. Within the L38 Area, the existing lift stations may be a limited source of emissions; thus, expansion of lift station L38 may result in more emissions. However, that would be offset at least by a decrease in emissions resulting from the abandonment of L25. Within the L39/L40 Area, combining lift stations L39 and L40 into one location may result in a reduction of emissions. Additionally, the site of the new combined lift station would be located farther from residential properties than either existing lift station L39 or L40. The project proposer will evaluate generator needs during the design process, but would maintain generators at lift stations that currently have them (unless the lift station is being eliminated). If it is decided that a generator will be used for peak shaving, air emission calculations must be completed to determine if an Air Emissions Permit is required. If required, the permit will be obtained.

24. Odors, noise and dust. Will the project generate odors, noise or dust during construction or during operation? Yes No

If yes, describe sources, characteristics, duration, quantities or intensity and any proposed measures to mitigate adverse impacts. Also identify locations of nearby sensitive receptors and estimate impacts on them. Discuss potential impacts on human health or quality of life. (Note: fugitive dust generated by operations may be discussed at item 23 instead of here.) Heavy equipment used during construction activities will result in exhaust odors, noise, and dust (from disturbed soils). Dust will be mitigated by regular cleanup of the construction site; water will be used to wet appropriate surfaces to reduce airborne dust when necessary. Noise and odor impacts from construction equipment will be controlled by restricting the hours of operation to daylight hours, or those permitted by local ordinances, if more restrictive. As in any sanitary sewer system, there is potential for odors to be associated with construction on existing facilities and/or to form during operation of the proposed system. Few odor complaints have been registered for this project area. Odor control methods can be incorporated into the design of the system, if warranted. The final decision on whether to include odor control equipment will be made during the design phase.


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. The project areas generally provide scenic views of Lake Minnetonka and surrounding water bodies. The proposed project will not permanently alter any scenic views. Archaeological, historical, and architectural resources are shown in Figures 17, 18, 19, 20, and 21. Wayzata/Orono Area Archaeological, Historical, or Architectural Resources (See Attachment 3 and Figures 17 and 18) According to a search of the SHPO database, eleven archaeological site locations were identified in the vicinity of the project. Construction of the proposed interceptor in the L26 Area will follow existing road right-of-way and will not disturb the archaeological sites. Archaeological sites in the L46/L49 Area lie outside the project area and will not be disturbed by any construction activities. SHPO also identified ten historic sites in the vicinity of the project. Seven of the sites are located on Lake Street, passing through downtown Wayzata. The interceptor through this area will be built within existing city, county, or railroad right-of-way and, therefore, will not directly affect any of these sites. However, access to these locations will be hindered during construction. The remaining three historic properties (in the L26 Area) are located on County Road 101. Access to the Sweat Estate may be hindered during construction, but no permanent impacts to any of the historic sites will result from the proposed project. The three historic properties in the L46/L49 Area are not in the area of construction, and will not be impacted by the proposed improvements. Designated Parks, Recreation Areas or Trails (See Figures 17 and 18) There are three city of Wayzata parks in the vicinity of the proposed interceptor and expanded L26 lift station. The Great Northern Railroad Depot at 402 Lake Street East is designated as a city park. Also, Gray’s Bay Causeway Park is located on the east side of Gray’s Bay off of County Road 101. This highly utilized concrete launch includes 30 parking spaces. In downtown Wayzata, there is a boardwalk between the two parks shown on the western end of the L26 Area. There is also an existing bike/walking trail that follows the BNSF right-of-way, paralleling McGinty Road from approximately Circle Drive to Bushaway Road/County Road 101. The city of Wayzata Comprehensive Plan and Hennepin County’s Trail Plan also show a proposed trail along Bushaway Road and McGinty Road. Hennepin County is planning to include an eight-foot paved shoulder along both of these roadways as part of the County Road 101 reconstruction project, to be installed after construction of the MCES-proposed improvements.


There are no parks in the vicinity of the L46/L49 Area in Orono. A portion of the Three River Park District’s planned Dakota Rail Regional Trail is located just south of the L46/L49 Area. However, the L46/L49 project would not affect this trail.

Mound/Minnetrista Area Archaeological, Historical, or Architectural Resources (See Attachment 3 and Figure 19) The city of Mound is known for its rich cultural history, with several burial mounds and historic buildings located in the city. However, through consultations with the SHPO, it has been determined that none of the archaeological or historic architecture site locations are within 1/4 mile of the project site. Project construction is not anticipated to have potential to impact the archaeological site locations. The presence of fill soils, and cut and fill lands along the project alignment suggests that if cultural resources existed there at one time, urban development would have impacted them prior to the proposed sewer construction.

Designated Parks, Recreation Areas, or Trails (See Figures 19 and 20) Several park, open space, and trail resources are located within the study area. Descriptions of resources in the vicinity of planned improvements and the potential impacts to them are provided below. Lake Minnetonka Regional Park (Three Rivers Park District) is a 292-acre park that includes a visitor center, picnic areas, a swimming pond, boat launch, and fishing pier to Lake Minnetonka, recreational trails, and a children’s play area. Figure 19 shows that the southernmost extent of forcemain construction in the L38 Area is proposed to occur adjacent to the existing interceptor that follows the old County Road 44 alignment through present-day Lake Minnetonka Regional Park. The project ends by connecting to the existing gravity flow interceptor (as shown in Figures 19 and 20).

Construction of the forcemain through this Regional Park is planned to be done by digging a trench for access to the proper pipe location. Given the location of the existing interceptor, this trench will likely restrict access to portions of the park, including the dog trail and northern parking lots and boat launch. The extent of the impact will not be known until final design; however, closure of this access road during a portion of the construction period is a possible outcome. MCES has begun discussions with Three Rivers Park District about this issue and will continue to coordinate design and construction timing in order to minimize impacts. For example, construction may be scheduled for the winter season, when the number of park users is lower than in the summer.

Dakota Rail Regional Trail (Three Rivers Park District) is a proposed multi-use bituminous-pavement trail that would extend from Wayzata and follow the previous Dakota Rail (railroad) corridor along the north side of Lake Minnetonka west to St. Bonifacius, and ultimately to the city of Hutchinson in McLeod County. The Three Rivers Park District, the agency that ultimately would be responsible for portions of the trail in Hennepin County, has developed a master plan for 13.5 miles of the trail, including the section through Mound. Three Rivers Park District has begun construction of this trail; completion and opening of the Wayzata to St. Bonifacius portion of the trail is scheduled for the fall of 2008.

As can be seen in Figure 19, the existing gravity interceptor and proposed new gravity interceptor is located within the Dakota Rail corridor. Construction of the new gravity interceptor would require digging a trench that likely precludes any other use of the corridor, including recreational trail uses, during the construction period. Given the status of design and funding for this proposed interceptor project, the schedule for construction of a new gravity interceptor in this corridor is likely after completion of the trail. Coordination with Three Rivers Park District on this issue is ongoing and efforts to minimize impacts to the trail will occur during the design and construction of the interceptor.


Swenson Park (city of Mound), as shown in Figure 19, is located in the L39/L40 Area. This park includes tennis and basketball courts, a ball field, playground equipment, and picnic areas. Figure 19 depicts the general location of the proposed interceptor construction. In general, the pipe will run under the southern border of the park. This should help to minimize construction impacts for most, if not all, park activities. The basketball court on the east side of Swenson Park may be impacted, pending final design measures to route the interceptor from the park and into the Bradford Lane right-of-way.

The Bob Miller Preserve and Hardscrabble Woods areas, both in the vicinity of County Road 44, are nature areas preserved as open space. No impacts to these resources will occur as a result of this project. Excelsior/Shorewood/Greenwood Area Archaeological, Historical, or Architectural Resources (See Attachment 4 and Figure 215C) According to SHPO database request responses for the Shorewood Area, there are no archaeological or historic sites in the vicinity of the proposed improvements to L21 and the 7017 forcemain. Figure 21 shows the locations of two archeological sites (St. Albans Mounds and Gideon’s Bay Mounds) in the Excelsior Area that may be in close proximity to the proposed improvements. The construction of the proposed interceptor generally occurs within existing street right-of-way and will likely not encroach on archaeological sites or historic properties.

As shown on Attachment 4, there are many historic sites in the Excelsior Area. Generally, the proposed interceptors and lift stations in the Excelsior Area are located on the following streets: Water Street, College Avenue, William Street, Oak Street, Beehrle Street, George Street, Morse Street, Excelsior Boulevard, and Christmas Lake Road. None of the historic properties located near the proposed improvements are expected to be impacted because construction would generally occur in street right-of-way. However, access to these locations will be hindered during construction.

Designated Parks, Recreation Areas, or Trails (See Figure 21) As shown on Figure 21, the North Loop of the Southwest Regional Light Rail Transit (LRT) Trail passes through this study area. This trail uses abandoned rail beds to create a connection between Carver Park Reserve to the west and the cities of Minnetonka and Hopkins to the east. The Southwest Regional LRT Trail is on a corridor that was purchased by the Hennepin County Regional Railroad Authority (HCRRA) for future light rail transit use. Three Rivers Park District signed a cooperative agreement with HCRRA for use of the corridor as a recreational trail in the interim. The trail is maintained as a ten-foot wide crushed limestone, multi-use trail.

In Excelsior, a portion of the Southwest Regional LRT Trail is used by the Minnesota Streetcar Museum as a route for the Excelsior Streetcar Line. From the Excelsior Boulevard to Water Street crossings of the Regional Trail (approximately one-half mile in length), historic streetcar service is provided from May through October. A “carbarn” is also located along the trail, immediately north of and adjacent to Trunk Highway 7 right-of-way. This building is a garage and maintenance/restoration facility for streetcars.

The proposed interceptor improvements cross the Southwest Regional LRT Trail at two locations: 1) Excelsior Boulevard (outside of the Excelsior Streetcar Line route); and 2) Morse Avenue (in conflict with the Excelsior Streetcar Line route to Water Street from the carbarn). Construction impacts may require interim periods of trail closure and limited operability of the streetcar, but such actions should be avoidable or minimized by construction timing or other mitigation techniques, to be determined through coordination with Three Rivers Park District and the Minnesota Streetcar Museum.


26. Visual impacts. Will the project create adverse visual impacts during construction or operation?

Such as glare from intense lights, lights visible in wilderness areas and large visible plumes from cooling towers or exhaust stacks? Yes No If yes, explain.

27. Compatibility with plans and land use regulations. Is the project subject to an adopted local comprehensive plan, land use plan or regulation, or other applicable land use, water, or resource management plan of a local, regional, state or federal agency? Yes No

If yes, describe the plan, discuss its compatibility with the project and explain how any conflicts will be resolved. If no, explain. The 1976 Metropolitan Land Planning Act requires local governments to prepare comprehensive plans and submit them to the Metropolitan Council to determine their consistency with metropolitan system plans. These are known as Tier I plans. The local comprehensive plan is to include a sewer element addressing the collection and disposal of wastewater generated by the community. Further, under Minn. Stat. § 473.513, local governments are required to submit a Comprehensive Sewer Plan (CSP) describing service needs from the MCES to the Metropolitan Council for its approval. These are known as Tier II plans. The CSP is broader in scope than the sewer element of the local comprehensive plan and provides detailed sewer system engineering information. The CSPs for communities in the Lake Minnetonka portion of the Blue Lake Service Area project increases in required service for regional interceptor system. The interceptor system provides collection services for communities in the service area. The interceptor system’s capacity is limited and requires relief to meet the future services needs. The sizing of the improvements is directly related to the flow projections for the communities served through ultimate development. The Metropolitan Council is working with the communities regarding the detailed design of the lift stations and interceptors. This project is compatible with the affected communities’ comprehensive plans and CSPs.

28. Impact on infrastructure and public services. Will new or expanded utilities, roads, other infrastructure or public services be required to serve the project? Yes No If yes, describe the new or additional infrastructure or services needed. (Note: any infrastructure that is a connected action with respect to the project must be assessed in the EAW; see EAW Guidelines for details.) The project alone will not require additional infrastructure. However, as development of the area progresses, other utilities and infrastructures, such as roads, collector streets, collector sewers, potable water distribution systems, stormwater collection and treatment systems, schools, police, fire protection, and other urban services will be needed to serve the area. Each community’s comprehensive plan will ensure coordination of infrastructure for enabled development.


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). Due to the nature of the proposed project, it is not anticipated to directly interact with any past, present, or reasonably foreseeable future projects in such a way as to cause cumulative effects. However, it is recognized that the construction of the proposed project will enable future growth and development within the service area, and that this enabled development may create secondary impacts. For example, enabled development may lead to a decrease in wildlife habitats or an increase in traffic. Increased impervious surface created by development may increase stormwater runoff and impacts to receiving waters. New development, however, will only occur if local economics support growth. The level of detail of development plans varies from city to city. Even development that is currently “planned” may be subject to change, particularly when projecting beyond the next few years. For that reason, it is very difficult to determine how much development the proposed project will enable and how much will be undertaken in the reasonably foreseeable future. Therefore, it is very difficult to determine how and to what extent development may contribute to cumulative effects. With that in mind, the area to be served by the proposed project includes a number of municipalities and, as such, has a wide range of proposed developments. Attachment 5 to this EAW provides information on predicted population growth and planned developments for the communities in the service area of the proposed project. The attachment lists EAWs (which analyze a specific project) and Alternative Urban Areawide Reviews (which analyze development scenarios for a defined area) that have been completed in the last six years for development within the service area. Future development not shown in the attachment may be subject to environmental review, and any construction project that disturbs an acre or more of land requires a Construction Stormwater Permit, to include an SWPPP, from the MPCA. In addition, Attachment 5 shows that 24 of the 25 involved communities are part of the MPCA Stormwater Program for MS4s (municipal separate storm sewer systems). The Stormwater Program for MS4s regulates stormwater discharge through the use of NPDES Permits and is designed to reduce the amount of sediment and pollution that enters surface and ground water from storm sewer systems to the maximum extent practicable. Adherence to comprehensive plans and development regulations, in addition to compliance with local, state, and federal permit requirements will help to ensure that environmental impacts are minimized and/or mitigated. Considering what is known at this time and the mitigation measures that are available, significant environmental effects due to cumulative impacts from this project or from the development enabled by this project are not expected.

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. NA

Documents

Lake Minnetonka Area Regional Interceptor EAW