South Sewer Interceptor - EID - Review Only

Environmental Information Document/Environmental Report - Interceptor Replacement and Miscellaneous Projects Project No. 16SG02 January 20, 2021 PRESENTED TO PRESENTED BY Oklahoma Water Resources Board 3800 N. Classen Blvd. Oklahoma City, OK 73118 City of Stillwater, Oklahoma Stillwater Utilities Authority PO Box 1449 Stillwater, OK 74076-1449 Contributions by: Prepared by: Curtis Bowling, PE Project Engineer March 18, 2021 Tetra Tech Steve Votaw Environmental Coordinator March 18, 2021 Eagle Environmental Consulting, Inc. Reviewed by: Approved by: Ryan Mittasch, PE Project Manager March 18, 2021 Tetra Tech David Barth, PE Senior Project Manager March 18, 2021 City of Stillwater Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project ii Table of Contents 1.0 PROJECT SCOPE

...............................................................................................................................................1 2.0 PROJECT PLANNING AREA ..............................................................................................................................2 2.1 Project Locations ............................................................................................................................................3 2.2 Growth and Population Trends ......................................................................................................................3 2.3 Current and Projected Wastewater Flow .......................................................................................................3 2.3.1 Current Flows .......................................................................................................................................3 2.3.2 South Interceptor Projected Flow .........................................................................................................3 2.4 Environmental Concerns in Service Area ......................................................................................................6 2.5 Community Engagement ...............................................................................................................................6 3.0 EXISTING FACILITIES AND NEED FOR PROJECT ..........................................................................................6 3.1 Condition of Existing Facilities .......................................................................................................................6 3.1.1 South Interceptor ..................................................................................................................................6 3.1.2 Boomer Creek Crossing .......................................................................................................................7 3.1.3 10-inch Connector Line ........................................................................................................................9 3.2 Health and Safety ...........................................................................................................................................9 3.3 Growth Capacity .............................................................................................................................................9 3.3.1 Interceptor Capacity .............................................................................................................................9 3.4 Sanitary Sewer System AVailability ...............................................................................................................9 4.0 ALTERNATIVES CONSIDERED .........................................................................................................................9 4.1 Summary of Alternatives Considered ......................................................................................................... 10 4.1.1 South Interceptor ............................................................................................................................... 10 4.1.2 Boomer Creek Inverted Siphon Structure Crossing .......................................................................... 11 4.1.3 10-inch Connector Line ..................................................................................................................... 12 5.0 ENVIRONMENTAL IMPACTS OF SELECTED ALTERNATIVE ..................................................................... 14 5.1 Land Use ..................................................................................................................................................... 14 5.2 Growth Areas and Population Trends/Projections ...................................................................................... 14 5.2.1 Social Environment ............................................................................................................................ 14 5.2.2 Environmental Justice .................................................................................................................... 16 5.2.3 Protection of Children ..................................................................................................................... 16 5.3 Natural Resources ...................................................................................................................................... 17 5.3.1 Soils ................................................................................................................................................ 17 5.2 Vegetation ...................................................................................................................................... 17 5.4 Water & Rrelated Resources ...................................................................................................................... 18 5.4.1 Floodplains ........................................................................................................................................ 19 5.4.2 Wetlands ............................................................................................................................................ 20 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project iii 5.5 Fish and Wildlife .......................................................................................................................................... 20 5.5.1 Threatened and Endangered Species ............................................................................................... 23 5.6 Cultural Resources ...................................................................................................................................... 26 5.6.1 SHPO Consultation ........................................................................................................................... 26 5.6.2 Tribal Consultation ............................................................................................................................. 26 5.7 Air Quality .................................................................................................................................................... 27 5.8 Hazardous Waste - Environmental Due Diligence ...................................................................................... 28 5.9 Geology ....................................................................................................................................................... 29 5.10 Climate Change ........................................................................................................................................ 29 5.11 Noise ......................................................................................................................................................... 30 5.12 Cumulative effects ..................................................................................................................................... 30 6.0 MANAGEMENT AND MITIGATION MEASURES ............................................................................................ 33 7.0 REFERENCES .................................................................................................................................................. 35 8.0 APPLICABLE ENVIRONMENTAL LAWS AND REGULATIONS ................................................................... 36 9.0 AGENCY/TRIBAL COORDINATION AND PUBLIC PARTICIPATION ........................................................... 37 10.0 DOCUMENT AUTHORSHIP AND CONTRIBUTION ..................................................................................... 42 LIST OF FIGURES AND EXHIBITS Figures Figure 1 – Project Location Map…………………………………………………………………………………………...2 Figure 2 – Proposed Action Alternative Map………………………………………………………………………….4-5 Figure 3 - Floodplain Location Map…………………………………………………………………………………21-22 Exhibits Exhibit 1 - Overall Condition of South Interceptor……………………………………………………………………..7 Exhibit 2 – Conceptual Design of South Interceptor…………………………………………………………………..8 Exhibit 3 - Existing Boomer Creek Inverted Siphon .............................................................................................8 Exhibit 4 – Conceptual Design of Inverted Siphon Structure ..............................................................................8 Exhibit 5 - Alternative 1 - Alignment North of Existing Alignment with 48” FRP………………………………..11 Tables Table 1 – Engineering Alternatives Matrix .......................................................................................................... 13 Table 2 – City of Stillwater Demographics……………………………………………………………… ................... 14 Table 3 – Federally-listed Threatened and Endangered (T&E) Species ........................................................... 23 Table 4 – T&E Species Conclusion Table ........................................................................................................... 25 Table 5 - National Ambient Air Quality Standards ............................................................................................. 27 Table 6 – Resource Impact Matrix ........................................................................................................................ 32 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project iv APPENDICES Appendix A – Representative Photographs Appendix B – Agency and Tribal Coordination and Public Engagement Documentation Appendix C – Waters of the United States Delineation Report of Survey Appendix D – Biological Assessment Appendix E – Hazardous Materials Assessment ACRONYMS/ABBREVIATIONS Acronyms/Abbreviations Definition ADF Average Daily Flow Rate ARV Combination Air/Vacuum Release Valve BFE Base Flood Elevation CIP Cast Iron Pipe CIPP Cured In-Place Pipe DIP Ductile Iron Pipe FEMA Federal Emergency Management Agency FRP Fiberglass Reinforced Pipe gpcpd Gallons Per Capita Per Day gpm Gallons per minute HP Horse Power I/I Inflow and Infiltration LS Lift Station MGD Million Gallons per Day O&M Operation and Maintenance ODEQ Oklahoma Department of Environmental Quality OAS Oklahoma Archeological Survey OHS Oklahoma Historical Society ONHI Oklahoma Natural Heritage Inventory OWRB Oklahoma Water Resources Board PLC Programmable Logic Controller PVC Polyvinyl Chloride RCP Reinforced Concrete Pipe S&L Smith and Loveless SUA Stillwater Utilities Authority TOFF Tulsa Ordinance Flow Formula USACE United States Army Corps of Engineers USFWS United States Fish and Wildlife Service WWTP Wastewater Treatment Plant Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 1 1.0 PROJECT SCOPE The purpose of the proposed action is to replace deteriorating and aging components of the City of Stillwater’s sanitary sewer collection system. The need for the proposed action is to prevent structural failures and restrictions that could result in sanitary sewer overflows. Capacity enhancements are included in the replacement of the deteriorated interceptor in order to convey additional flow to the wastewater treatment plant as future development occurs. The Stillwater Utilities Authority (SUA) engaged the consulting engineering firm Tetra Tech to perform design, bid, and construction phase services for the overall City of Stillwater Sanitary System Improvement project and included following engineering objectives:  Rehabilitate or replace the Foxfire Lift Station servicing a small development  Rehabilitate or replace approximately 730 linear feet of the interceptor servicing the northeast portion of the City (Northeast Interceptor)  Replace an 18-inch drain line that drains the WWTP’s clarifiers.  Rehabilitate or replace approximately 7,500 linear feet of the interceptor servicing the south and west portions of the city (South Interceptor) including an inverted siphon structure crossing of Boomer Creek  Replace the existing Aerial Creek Crossing over the Stillwater Creek Tributary near Main Street and W. 15th Avenue The engineering objectives seek to accomplish the following:  Improving the efficiency of the lift station by replacing the improperly sized pumps operating at 35% efficiency as well as replacing the corroding wet well and reducing odor issues reported by residents nearby  Improving the heavily deteriorated Northeast Interceptor near the headworks of the plant to prevent catastrophic failure. The pipe size will also be increased to account for future projected growth in the service area  Replacing the deteriorated and clog-prone drain line for the WWTP’s primary clarifier to allow for better maintenance for the plant and operators  Improving the heavily deteriorated South Interceptor, which had collapses in 2015 and 2019. The pipe size will be increased to account for future projected growth in the service area. This will also improve an aging inverted siphon creek crossing and the natural flow path of the creek by removing the existing inverted siphon piping exposed in the creek bed  Replacing an aerial creek crossing that has been temporarily supported to prevent total failure and sanitary sewer overflow into the creek Tetra Tech evaluated viable alternative approaches for each of the objectives listed above. These alternatives were presented to the City on August 8th, 2019 in the form of a presentation and alternatives decision matrix. Thereafter, Tetra Tech prepared an engineering report summarizing the evaluated alternatives for each stated objective and presented the recommendations for design. The engineering report was submitted to the City on January 7, 2020. The City reviewed the engineering report and authorized commencement of the overall project design. Through coordination with the City and OWRB, it was determined four facets of the overall project would meet the requirements for Categorial Exclusions and would not be evaluated as part of this EID. Those project facets included:  Rehabilitate or replace the Foxfire Lift Station servicing a small development  Rehabilitate or replace approximately 730 linear feet of the interceptor servicing the northeast portion of the City (Northeast Interceptor)  Replace the 18-inch drain line that drains the WWTP’s clarifiers  Replace the existing Aerial Creek Crossing over the Stillwater Creek Tributary near Main Street and W. 15th Avenue Based on expected construction costs which would exceed the proposed budget allocation, the City amended the engineering contract in April 2020 to include preparation of the Environmental Information Document for two of the overall project facets. Subsequently, the City of Stillwater applied for funding assistance from OWRB. The project facets requiring evaluation within this EID due to the OWRB funding assistance request include: Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 2  Replacement of approximately 7,500 feet of the South Interceptor including, including the inverted siphon structure crossing of Boomer Creek  Construct a southern extension of 10-inch line (south from the South Interceptor) for a distance of 943 feet to connect with the existing line that continues south of Stillwater Creek 2.0 PROJECT PLANNING AREA This EID has been prepared to identify, describe and evaluate the potential environmental impacts associated with the South Interceptor, including the Inverted Siphon Structure Crossing of Boomer Creek and construction of the southern extension of a 10-inch Gravity Line. Photographs of the proposed action area are provided in Appendix A. The facets of the proposed project associated with this EID involve installation of approximately 7,500 feet of the South Interceptor including, an inverted siphon crossing of Boomer Creek, and the southern extension of a 10- inch line (from the South Interceptor) for a distance of 943 feet that connects to the existing line that extends south of Stillwater Creek. The collective utility line corridor footages would be 9,388 and the environmental survey corridor width for each was 50 feet. The overall survey corridor area was approximately 9.70 acres. However, the anticipated disturbance corridor would be limited to 25 feet and result in the disturbance to 4.85 acres of vegetation and soils. The disturbance corridors transition across herbaceous fields used for agriculture crops, hay production, and/or bio- solids injection fields. The section of the South Interceptor line either side of Boomer Creek would transition through a partially cleared and maintained corridor adjacent to the existing interceptor line (which will remain in place). Approximately 0.25 acres of trees will be removed along the northern limit of the previously cleared woody vegetation associated with the existing South Interceptor line. The acreage of herbaceous vegetation impact would be 4.60. The general location of the project is shown on Figure 1. Below are summaries of the facets, design objectives, and their service areas. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 3 2.1 PROJECT LOCATIONS The project areas are located approximately 2 miles south and east of Stillwater, OK. The proposed project is located on the Stillwater South Quadrangle 7.5-minute USGS topographic map. The respective line segments are situated in Sections 29 & 20, Township 19 North, Range 3 East and Section 25, Township 19 North, Range 2 East, Payne County, Oklahoma. Each of the proposed line segments are depicted on Figure 2 for visual reference and spatial perspective. South Interceptor Replacement The South Interceptor services the south and mid portions of the City of Stillwater. The section of interceptor to be replaced is located between the WWTP headworks building to Manhole ID 3040. This portion of the interceptor extends west from the WWTP before turning northwest toward the Boomer Creek crossing with proposed inverted siphon structure. The interceptor continues west and then northwest to the western terminus and connection point with the existing South Interceptor. Boomer Creek Crossing The Boomer Creek inverted siphon crossing is located along the South interceptor, just upstream of Boomer Creek and Stillwater Creek confluence. Ten-inch Line Replacement The proposed 10-inch line section is located between the new South Interceptor line and the connection point with an existing 8-inch line in an agriculture field above the left descending bank of Stillwater Creek. The existing 8-inch line crossing Stillwater Creek would not be altered nor would Stillwater Creek be affected. 2.2 GROWTH AND POPULATION TRENDS Prior to developing alternatives for the south interceptor, Tetra Tech was tasked with sizing the new utility line for to accommodate both the current population and future growth. The current population of Stillwater is approximately 50,391 people based on the United States Census website for July 1st, 2019. Tetra Tech projected flows for 2055 using a future population of 116,090 based on City of Stillwater’s Wastewater Master Plan. Using the projected population growth rates and expected capacity needs, the south interceptor size was calculated and designed to accommodate the expected population increases and future flow rate capacity requirements. 2.3 CURRENT AND PROJECTED WASTEWATER FLOW 2.3.1 Current Flows Flow monitoring was conducted by Tetra Tech on the South Interceptor in late 2017. The monitor recorded reliable dry weather flow data, however, there were no significant rain events to calculate peak wet weather flow rates and inflow and infiltration volumes. The average daily flow (ADF) of the Northeast Interceptor was calculated to be 0.92 million gallons per day (MGD) and 3.4 MGD for the South Interceptor. The current total average daily flow to the WWTP is 4.32 MGD, which equates to an average of 86 gallons per capita per day (GPCPD). Comparing the 22 MGD peak to the average daily flow of 4.32 MGD produces a current peaking factor of 5.1. 2.3.2 South Interceptor Projected Flow The future area contributing to the South Interceptor totals 23,315 acres including 4,288 acres of undevelopable land within the 100-year floodplain. Projected flows in the South Interceptor were calculated based on the remaining 19,027 acres, which accounts for approximately 60% of the area within the future municipal boundary. Three sizing formulas were used to calculate future flows to the South Interceptor. The first method was using the OWRB sewer sizing formula, which utilizes an average per capita flow rate and peaking factor to determine the required interceptor capacity. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 4 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 5 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 6 Multiplying 69,654 people (60% of the 2055 total population projection of 116,090 people) by the current average 86 GPCPD and applying the current peaking factor of 5.1 estimates the required future capacity of the South Interceptor to be 30.6 MGD. Tetra Tech also utilized the TOFF to compare to the peak flow estimated by the OWRB Formula for the South Interceptor. Using 19,027 acres for the projected south contributing area, the TOFF estimates the future peak flow as 46.0 MGD. ODEQ Standard 252:656-5-1 states to design for an average daily per capita flow of 100 gpd, which includes normal infiltration. This results in an average daily flow of approximately 6.9 MGD for 60% of the 2055 population in the South interceptor. ODEQ standards also state that peak design flow must be based on an acceptable (I/I) study or the ratio of peak to average daily flow from a widely recognized engineering standard. The TOFF formula result equates to approximately 660 GPCPD which is a 6.6:1 peaking factor as compared to the ODEQ design flow of 100 gallons per day (GPD). Based on the TOFF formula and the flow monitoring results of the existing system a peaking factor between 5 and 7 was determined appropriate. 2.4 ENVIRONMENTAL CONCERNS IN SERVICE AREA Multiple potential environmental concerns were considered during design of the proposed action and are addressed within this EID. All precautionary and/or preventative measures to avoid or minimize potential adverse environmental impacts identified through this EID will be incorporated into the final engineering/construction plans for contractor implementation. The primary environmental concerns would be related to potential impacts to cultural resources, waters of the United States, threatened and endangered species/wildlife, erosion control/sedimentation, and accidental discharges of petroleum products. Other potential environmental areas of concern have also identified and are addressed herein. EEC provided project scoping letters to city, county, state, federal and tribal entities whereby concerns pursuant to their respective administrative responsibilities were requested relative to the proposed action. The provided scoping letters and received responses are located in Appendix B. Discussion and evaluation of the respective public interest review factors are provided in Section 5.0 below. 2.5 COMMUNITY ENGAGEMENT The City held a public meeting at the City of Stillwater City Hall at 5:30pm on April 21, 2021 offering an open forum through which the citizens of Stillwater were provided an opportunity to learn about the proposed project and present any comments or concerns. The public meeting time, date, and location and notice of availability of the Draft Environmental Information Document review was advertised in the Stillwater Newspress newspaper on March 20, 2021 and posted to the City’s website (http://www.stillwater.org/. A copy of this EID was made available for public review on the website and a bound copy of said document was also made available at the public meeting venue. Public comments through both coordination venues were encouraged and each received comment along with the City’s responses are provided in Appendix B. The newspaper public notice announcement advertisement affidavit is also provided in Appendix B. 3.0 EXISTING FACILITIES AND NEED FOR PROJECT 3.1 CONDITION OF EXISTING FACILITIES Each of the proposed project facets currently meet Federal, State, and local regulations regarding the water pollution control standards. However, the issues and/or concerns relative to each which necessitate replacement of the existing structures is detailed below. The identification and discussion of the project alternatives considered, including those not selected, during the engineering and design phase are provided in Section 4.0 below. 3.1.1 South Interceptor The South Interceptor services the south and mid portions of the City of Stillwater. The section of interceptor to be replaced in this project is from the WWTP headworks building to Manhole ID 3040. This portion of the interceptor consists of Type III and Type IV RCP pipe including 7,116 linear feet of 36-inch pipe and 357 linear feet of 42-inch pipe. This section of the interceptor also includes the existing inverted siphon crossing of Boomer Creek. The existing capacity of the 36-inch piping is 13.63 MGD based on a Manning’s “n” of 0.013 and a slope of 0.001 ft/ft. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 7 Failures have occurred on the interceptor resulting in expensive emergency repairs. CCTV inspection of this pipe verified that it is in poor condition and warrants full rehabilitation or replacement (Exhibit 1). Exhibit 2 provides an alignment overview of the South Interceptor. Exhibit 1- Representative Condition of South Interceptor Exhibit 2 - Proposed Action and Existing South Interceptor Alignments 3.1.2 Boomer Creek Crossing The Boomer Creek inverted siphon was originally installed in 1962, during the initial construction of the South Interceptor. It consists of three, 18-inch cast iron pipe (CIP) barrels spanning 108 linear feet between the siphon structures on each side of the creek. Scouring of the creek bed has partially exposed the barrel sections (Exhibit 3). This inverted siphon is part of the South Interceptor alignment requiring replacement due to corrosion and deterioration of the sewer main. Exhbit 4 provides the siphon structure coneptual layout. Existing So. Interceptor Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 8 Exhibit 3 - Existing Boomer Creek Inverted Siphon Exhibit 4 – Conceptual Layout of Boomer Creek Siphon Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 9 3.1.3 10-inch Connector Line Currently, an 8-inch gravity line connects with the existing South Interceptor services a small development located south of Stillwater Creek. The relocation of the South Interceptor to the new alignment (further north) would require an extension of this 8-inch gravity line. However, the existing 8-inch flowline elevations and length of potential extension (to the new South interceptor) do not allow an 8-inch line to be installed due to the minimum slope requirement of 0.40% (for the 8-inch line). The minimum slope requirement for a 10-inch line is 0.29% and can be achieved. Therefore, upsizing to a 10-inch line was required. The new line will connect to the 8-inch line at an existing manhole north of Stillwater Creek and transition north to the new South Interceptor connection point. This new extension will be a 10-inch diameter PVC pipe as specified in the engineering report. The existing 8-inch line will remain in place. 3.2 HEALTH AND SAFETY No health and safety issues are expected to be present during the construction of the project. The sewer improvements for the South Interceptor, Boomer Creek Inverted Siphon Crossing, and the 10-inch line extension are located in unpaved, untraveled areas and the earthen surface restoration will be completed by returning the affected areas to the pre-existing conditions to the extent possible and revegetated using native herbaceous species. The South Interceptor would partially transition through existing bio-solids injection fields. Organic materials and/or compounds associated with the injected solids would be present within the proposed construction corridor. Once bio-solids are injected, chemical processes occur leading to the breakdown of organic compounds. Said breakdown facilitates assimilation and utilization of injected organic materials by existing bacteria, micro- organisms, and vegetation. Resultant from these processes, concentrations of organic compounds are decreased, recombination of elemental valences results, and separation of complex compounds occur. As compound breakdown occurs, free elements such as phosphorus, nitrogen, potassium, and carbon may be reduced to more isolated forms that facilitate vegetative root system uptake and removal. The overall chemical breakdown processes are intended to result in less concentrations of bio-solids. Precautionary measures will be employed by the construction contractor to the ensure health and safety of their personnel similar to those measures utilized during actual bio-solids handling/injection by City staff. No evidence of vegetation stress was observed during the field surveys as referenced in the Hazardous Materials Assessment (Appendix E). 3.3 GROWTH CAPACITY 3.3.1 Interceptor Capacity The South Interceptor is planned for an increase in capacity to meet projected flows of the year 2055. The projected flow calculations for the interceptor is listed in Section 2.3, above. The increase in sewer sizing is a minimal cost compared to upsizing the pipes as a separate project at a later date. Increasing the sewer size as a part of this project is a cost conscience decision that benefits the City and the public in the future. 3.4 SANITARY SEWER SYSTEM AVAILABILITY The proposed project does not include any improvements to the WWTP. The increase in interceptor sizing will allow for increased future flow capacity to the WWTP. However, the existing WWTP will be improved or upgraded in the future as determined necessary. Failures have occurred on the South Interceptor resulting in expensive emergency repairs. CCTV inspection of this pipe verified its presently poor condition which warrants full rehabilitation or replacement. The existing 8-inch connector line is currently in adequate condition. However, upsizing said line to a 10-inch connector line is required due to inability of the 8-inch line to meet the required minimum slope when extended to the connection point with the South Interceptor alignment. The inverted siphon structure is dilapidated and partially exposed due to erosion of the banks of Boomer Creek. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 10 4.0 ALTERNATIVES CONSIDERED Tetra Tech developed various conceptual design alternatives to meet each project facet design objective. The list of alternatives to evaluate was refined based on feedback from the City. Tetra Tech then completed the alternatives evaluation and presented the results during the Alternatives Evaluation Workshop held on August 8th, 2019. The following sections provide a summary of each alternative considered. The proposed action alternative for each facet is presented first. The alternative designs considered but not selected for each project facet are presented thereafter. The rationale for proposed alternative selection as well as the reasons why the considered alternatives were not selected are also provided. Table 1 provides the engineering alternatives evaluation matrix identifying the decision factors and score ratings for each project facet which facilitated selection of the proposed action alternative. 4.1 SUMMARY OF ALTERNATIVES CONSIDERED 4.1.1 South Interceptor Tetra Tech based capacity calculations on fiberglass reinforced pipe (FRP) based on the success the City has recently experienced in using this material for interceptor sewer repairs. The calculated capacity of a 48-inch fiberglass reinforced pipe (FRP) is 46.2 MGD, assuming a Manning’s “n” of 0.009 and a slope of 0.001 ft/ft for stiffness class and pressure class SN18 and PN50, respectively. This provides a peaking factor of approximately 6.7 (46.2MGD /6.9MGD); therefore, Tetra Tech recommends a 48-inch FRP pipe (at a minimum) to handle the future flows in the South Interceptor. A minimum size of 48-inches for FRP pipe meets the capacity requirements of both the OWRB Formula and TOFF estimating. Conceptual design drawings for the South Interceptor are provided in Engineering Report. 4.1.1.1 Proposed Action (Alternative 2) – Parallel Existing Alignment with 48” FRP The proposed action alternative would parallel the existing south interceptor alignment, beginning at the western project terminus, for approximately 2,530 linear feet, then continue east to the WWTP. This alternative includes installation of 7,500 linear feet of 48-inch FRP pipe, twenty-one 8-feet diameter manholes, three 4-foot diameter manholes, and replacement of the Boomer Creek Inverted Siphon. The existing interceptor would be abandoned in place after construction of the new piping is complete. The bypass pumping efforts would be minimal since the new interceptor can be mostly constructed while the existing interceptor remains in service. Bypass pumping will only be required while switching service from the existing interceptor to the new interceptor. The proposed action alternative would necessitate modification of the existing 8-inch line that extends south of Stillwater Creek. Discussion of and rationale for necessitating this project facet is provided below under the proposed 10-inch Connector Line. The bypass pumping efforts for Alternative 2 should be minimal since the new interceptor can be mostly constructed while the existing interceptor remains in service. Bypass pumping will only be required while switching service from the existing interceptor to the new interceptor. Tetra Tech assumed a maximum of 30 days of bypass pumping for this alternative. A larger interceptor size will meet the goal of increasing the capacity to contain projected flow rates for the year 2055. The City owns most of the land along this alignment, but permanent easement should be established for the entire length to ensure future access to the interceptor. Temporary construction easements will also be required for the properties south and west of the siphon that are not City-owned. 4.1.1.2 Alternative 1 – Alignment North of Existing Alignment with 48” FRP Alternative 1 would parallel to the existing alignment the entire length of interceptor replacement (see Exhibit 5 below). Alternate 1 would be approximately 1,000 feet longer than Alternative 2. The following factors would be the same as described for the proposed action:  Bypass pumping efforts and duration  Larger pipe size would accommodate flows project for Year 2055.  The City owns most of the land along this alignment, but permanent easement should be established for the entire length to ensure future access to the interceptor.  Temporary construction easements will also be required for the properties south and west of the siphon that are not City-owned. Alternative 1 would result in increased materials and construction costs compared to the proposed action. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 11 Exhibit 5 - Alternative 1 - Alignment North of Existing Alignment with 48” FRP 4.1.1.3 Alternative 1A – Paralleling Existing Alignment with 42” FRP Alternative 1A is the same as Alternative 1, with the only difference being the installation of 42-inch FRP instead of 48-inch. This alternative reduces flow capacity from 46.2 MGD to 32.7 MGD. 4.1.1.4 Alternative 2A – Alignment North of Existing Alignment with 42” FRP Alternative 2A is the same as Alternative 2, with the only difference being the installation of 42-inch FRP instead of 48-inch. The existing interceptor would be abandoned in place after construction of the new piping is complete. The 48-inch FRP sewer meets the 2055 demands based on the OWRB sizing formula but not the TOFF sizing criteria (see section 3.2.2). Capacity flows would be decreased from 46.2 MGD to 32.7 MGD. 4.1.1.5 Do-Nothing Alternative If the do-nothing alternative is selected, the City will continue having total failures and collapses of the South Interceptor as it continues to corrode. These failures will require expensive emergency repair and temporary sanitary sewer service measures during the repair process. 4.1.2 Boomer Creek Inverted Siphon Structure Crossing 4.1.2.1 Proposed Action Alternative – New Siphon North of Existing Siphon Alternative 2 proposes a total replacement of the existing siphon structure with the new siphon structure to the north of the existing alignment. The western portion of Alternative 2 would be installed parallel to the existing South Interceptor to the point of divergence identified on Exhibit 2 above. This includes two new concrete structures, one 20-inch and two 36-inch Ductile Iron Pipe (DIP) barrel sections that are each 318 linear feet long, and mechanical jointed DIP bends with thrust blocking. The existing siphon has three barrels of the same size while the new siphon will have two 36-inch DIP barrels utilized during wet weather flows and a single 20-inch DIP barrel sized to maintain flushing velocities during average flows. The depth of the new barrel beneath the creek bed would be approximately 3 feet. The upstream structure will be constructed with weir walls for directing flows to the proper barrel sections. This alternative will require minimal bypass pumping because it can be built while the existing siphon remains in service. The barrel piping will be buried deeper than the creek bed which will resolve the existing issue of exposed piping within the creek bed. The existing siphon piping will be removed as well as the top of the structures to three feet below grade. The remaining underground structures will then be backfilled. A conceptual drawing of the inverted siphon creek crossing is provided in Engineering Report. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 12 4.1.2.2 Alternative 1 – Aerial Creek Crossing Without Siphon Structure Early in the project, Tetra Tech explored an alternative to perform the creek crossing without a siphon structure. Due to flowlines of the existing system, the bottom of an aerial crossing pipe would only be a two to three feet above the creek bed. This would cause scouring of the creek bed under the pipe. Another concern was the aerial crossing supports that would be installed in the creek. The supports along with the low crossing pipe would require an engineering report and hydrologic analysis showing the impact on the floodplain elevation and may not be approved by the United States Army Corps of Engineers (USACE). For these reasons, this option was not furthered for analysis. 4.1.2.3 Alternative 2 – Replace/Rehabilitate Existing Siphon Alternative 2 suggests replacing the existing siphon in-place. This includes replacing the two concrete structures; replacing the three 18-inch DIP barrel sections with two 20-inch and one 36-inch Ductile Iron Pipe (DIP) barrel sections, and mechanical jointed DIP bends with thrust blocking. Alternative 2 will upgrade the capacity of the siphon to handle the South interceptor’s 2055 projected flow rates. The estimated construction cost for Alternative 2 would be approximately $150,000 higher than the cost for Alternative 1. The increased costs were attributed to significantly higher bypass pumping duration and cost because the siphon would be offline during siphon structure replacement activities. For these reasons, this option was not furthered for analysis. 4.1.2.4 Do-Nothing Alternative If the do-nothing alternative is selected, the exposed steel piping will continue to be undermined and corrode on the inside until the point of collapse. This will require expensive emergency repair and temporary sanitary sewer service measures during the repair process and will discharge sanitary sewer into Boomer Creek until the failure is discovered and the temporary service measures are in-place. The emergency repair will not be a quick, remove and replace due to the regulatory requirements for construction within floodplain. The review process to received approval for a new structure could take months and drive the costs to the City up for temporary service measures. 4.1.3 10-inch Connector Line 4.1.3.1 Proposed Action Alternative 2 – New 10-inch Gravity Line Currently, an 8-inch gravity line connects with the existing South Interceptor and services a small development located south of Stillwater Creek. The relocation of the South Interceptor to the new alignment (further north) would require an extension of this 8-inch gravity line. However, the existing 8-inch flowline elevations and length of potential extension (to the new South interceptor) do not allow an 8-inch line to be installed due to the minimum slope requirement of 0.40%. The minimum slope requirement for a 10-inch line is 0.29% and can be achieved. Therefore, upsizing to a 10-inch PVC line was required. The new line will connect to the 8-inch line at an existing manhole north of Stillwater Creek and transition north to the new South Interceptor connection point. The existing 8-inch line will remain in place. A conceptual drawing of the proposed 10-inch connector line is provided in Engineering Report. 4.1.3.2 Alternative 1 – Extend Existing 8-inch Gravity Line The existing 8-inch flowline elevations and the length of this extension to the South interceptor do not allow an 8- inch line to be installed at the minimum required slope of 0.40% required by ODEQ. The minimum slope requirements for a 8-inch line of 0.40% can be achieved. No other alternatives were considered and the condition of the existing line was not evaluated. Selection and use of the proposed 10-inch line were a function of and required due to relocation of the South Interceptor and inability to utilize an 8-inch gravity line. 4.1.3.3 Do-Nothing Alternative If the do-nothing alternative is selected, the aerial crossing will inevitably collapse, require expensive emergency repair, necessitate temporary sewer service measures during repairs, and will discharge sewer into Stillwater Creek. Repair would also require removal/replacement for construction within floodplain. The permit process to receive approval for a new structure could take months and increase costs to the City up for temporary service measures. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 13 Capital Cost Capital Cost Comparison Operational Reliability Construction Complexity Land and Easement Acquisition By-Pass Pumping Requirements 1 = Low 2 = Mod 3 = High 1 = High 2 = Mod 3 = Low 1 = High 2 = Mod 3 = Low 1 = Low 2 = Mod 3 = High 1 = Low 2 = Mod 3 = High 1 = Easy 2 = Moderate 3 = Difficult 1 = Not Required 2 = Required - Mod 3 = Required - Ext 1 = Required - Minimal 2 = Required - Mod 3 = Required - Ext Staff Familiarity Surface Features Odor Capacity Length of Interceptor South Interceptor 1 Parallel existing alignment with 48" FRP (entire length) Reduces by-pass pumping efforts, reduces design efforts, shorter 10" line, increased capacity Widen existing easement 3 1 1 3 0 2 1 2 13 1A Parallel existing alignment with 42" FRP (entire length) Reduces by-pass pumping efforts, reduces design efforts, shorter 10" line Widen existing easement 2 1 2 3 0 2 1 2 13 2 Parallel existing alignment with 48" FRP, then new north alignment to WWTP Interceptor shorter overall length, reduces by-pass pumping efforts, increased capacity New easement and widen existing easement likely required 2 1 1 1 0 2 2 2 11 2A Parallel existing alignment with 42" FRP, then new north alignment to WWTP Interceptor shorter overall length, reduces by-pass pumping efforts New easement and widen existing easement likely required 1 1 2 1 0 2 2 2 11 Boomer Creek Crossing 1 New siphon on north side of existing siphon Ease in construction (no bypass pumping required), piping to be buried deeper to avoid erosion Construction in creek channel 2 1 0 0 0 2 2 1 8 2 Replace/rehab existing siphon No change to existing operation; New pipe and siphon structures Will require extensive by- pass pumping 3 1 0 0 0 3 1 3 11 1 New Aerial Crossing without Siphon Structure Ease in construction (no bypass pumping required), piping to be buried deeper to avoid erosion Piping within creek channel, potential for scour, require support installation. 3 1 0 0 0 2 2 1 9 10-Inch Connector Line 1 Extend existing 8-inch line to connect with new South Interceptor alignment Slight construction cost savings Does not meet ODEQ minimum slope requirements 1 3 2 0 0 2 1 1 10 2 Construct new 10-inch lne to connect existing 8-inch line with the new South Interceptor alignment Allows ability to meet ODEQ minimum slope requirements None 2 1 1 0 0 2 1 1 8 Table 1 - Engineeering Alternatives Matrix Total Score Additional Considerations O&M Ranking Assignments (Lower score is preferred) Construction Option Number Alternative Description Benefits Challenges Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 14 5.0 ENVIRONMENTAL IMPACTS OF SELECTED ALTERNATIVE This section presents the general description of the conditions and resources relevant to the proposed action. Existing conditions and anticipated environmental impacts associated with the proposed action alternative for each project facet are described for the socioeconomic, physical, aquatic, and biological environment within the proposed action areas that may be affected. Construction would require removal of existing herbaceous and woody vegetation associated with grading of the existing landscape, soil disturbance during installation of the proposed utility lines, and restoration of the affected areas. Each utility line would be installed using conventional trenching techniques and the disturbed ground surface areas would be restored and revegetated. A storm water management plan will also be implemented and maintained to minimize soil loss and/or sedimentation associated with stormwater runoff to the extent possible during construction. The proposed construction/grading plan would be performed in accordance with standard engineering/construction guidelines and practices. 5.1 LAND USE Land use within the proposed action area consists of hay production, agriculture crop production, and bio-solids injection operations in the open field areas. No obvious land use was identified with the woodland area adjacent to the existing south interceptor alignment corridor among the riparian zone associated with Boomer Creek. Direct Impacts The proposed action alternatives would result in direct impacts to approximately 4.60 acres of property during utility line installation and/or preparatory vegetation removal. The landscape of the proposed action would primarily be affected on a temporary basis by clearing/grubbing, grading, trenching and backfill activities during construction. All areas would be restored upon project completion. No change in land use is anticipated. Indirect Impacts No indirect impacts or long-term adverse effects to the current land use are expected. 5.2 GROWTH AREAS AND POPULATION TRENDS/PROJECTIONS 5.2.1 Social Environment According to the poverty guidelines published by the US Department of Health and Human Services (HHS), the 2018 HHS poverty guidelines (Federal Register, January 18, 2018) for a family of four with an annual household income of $25,100 is considered to be the poverty level. An annual income of $12,140 is considered to be in the poverty level for an individual. U.S. Census Bureau data was used to identify the social characteristics at the city level (https://www.census.gov/quickfacts/stillwatercityoklahoma). Table 2 provides the summary information. Table 2. City of Stillwater, OK Demographics Population Population estimates, July 1, 2019, (V2019) 50,299 Population estimates base, April 1, 2010, (V2019) 45,721 Population, percent change - April 1, 2010 10.0% Population, Census, April 1, 2010 45,688 Age and Sex Persons under 5 years, percent 4.5% Persons under 18 years, percent 15.9% Persons 65 years and over, percent 9.2% Female persons, percent 48.3% Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 15 Direct Impacts No adverse direct impacts are anticipated by the preferred action alternatives on the social and economic environments. The social and economic environments are expected to follow historic trends in the project area vicinity. The proposed action may temporarily increase noise levels however no people or residential areas are located adjacent to or near the action area. Temporary noise levels increases are not expected to be excessive and would short duration. Quality of life improvements should be expected as a result of the proposed action through increase functionality of the City’s wastewater treatment system to prevent service disruptions associated with facility failures due to the degraded condition of the existing infrastructure. Temporary monetary benefit may also be realized by the selected construction contractor business, their employees, and by local businesses that provide materials and services to construction-related enterprises. Additional monetary benefits may also be realized by food and lodging establishments on a temporary basis from construction personnel patronage. Race and Hispanic Origin White alone, percent 77.3% Black or African American alone, percent(a) 4.6% American Indian and Alaska Native alone, percent(a) 4.1% Asian alone, percent(a) 6.7% Native Hawaiian and Other Pacific Islander alone % 0.1% Two or More Races, percent 6.4% Hispanic or Latino, percent(b) 4.7% White alone, not Hispanic or Latino, percent 73.6% Population Characteristics Veterans, 2015-2019 1,507 Foreign born persons, percent, 2015-2019 10.5% Housing Housing units, July 1, 2019, (V2019) X Owner-occupied housing unit rate, 2015-2019 37.2% Median value owner-occupied hsing units, 2015-2019 $184,900 Median selected monthly owner costs -with a mortgage, 2015-2019 $1,474 Median selected monthly owner costs -without a mortgage, 2015- 2019 $506 Median gross rent, 2015-2019 $832 Building permits, 2019 X Families & Living Arrangements Households, 2015-2019 18,585 Persons per household, 2015-2019 2.30 Living in same house 1 year ago, percent of persons age 1 year+, 2015-2019 63.3% Education High school graduate or higher, percent of persons age 25 years+, 2015-2019 94.5% Bachelor's degree or higher, percent of persons age 25 years+, 2015- 2019 48.7% Health With a disability, under age 65 years, percent, 2015-2019 6.0% Persons without health insurance, under age 65 years, percent 11.8% Economy In civilian labor force, total, percent of population age 16 years+, 2015-2019 57.6% In civilian labor force, female, percent of population age 16 years+, 2015-2019 54.3% Total accommodation and food services sales, 2012 ($1,000)(c) 134,819 Total health care and social assistance receipts/revenue, 2012 ($1,000)(c) 240,170 Total manufacturers shipments, 2012 ($1,000)(c) 343,232 Total merchant wholesaler sales, 2012 ($1,000)(c) 163,526 Total retail sales, 2012 ($1,000)(c) 739,162 Total retail sales per capita, 2012(c) $15,875 Transportation Mean travel time to work (minutes), workers age 16 years+, 2015- 2019 16.2 Income & Poverty Median household income (in 2019 dollars), 2015-2019 $34,309 Per capita income in past 12 months (in 2019 dollars), 2015-2019 $22,487 Persons in poverty, percent 35.2% Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 16 Indirect Impacts No indirect adverse impacts should result from the proposed action. 5.2.2 Environmental Justice Executive Order (EO) 12898 “Federal Actions to Address Environmental Justice in Minority and Low-Income Populations” (February 11, 1994) states that if possible, no federal actions should place any adverse environmental, economic, social, or health effects on minority or low-income groups. Direct Impacts The USEPA Environmental Justice Screening and Mapping Tool, EJSCREEN, Version 2018, was used to broadly assess the proposed action concerning effects on minority and low-income populations. Results from the EJSCREEN below indicate that the proposed action does not appear to have any environmental justice concerns. The proposed action would not displace any residential development or affect any minority groups or low-income families. Indirect Impacts No indirect impacts to minority or low-income populations are anticipated. 5.2.3 Protection of Children Executive Order 13045 pertains to “Protection of Children for Environmental Health and Safety Risks”, April 21, 1997. This mandate requires that federal agencies are to identify and assess environmental health and safety risks that may affect children. EO 13045 states that to the extent permitted by law and appropriate, each federal agency shall make it a high priority to identify and assess environmental health risks and safety risks that may disproportionately affect children and ensure that its policies, programs, activities, and standards address disproportionate risks to children that result from environmental health risks or safety risks. Direct Impacts The project passes through undeveloped areas on City and privately owned property. The project will be undertaken using safety precaution measures and safety barriers. No open trenches would remain open during non- construction periods. All open trenches will be manned by construction and/or City personnel during construction periods and public access will be prohibited. Project Area Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 17 Indirect Impacts No indirect impacts have been identified or are anticipated. 5.3 NATURAL RESOURCES 5.3.1 Soils The Natural Resource Conservation Service (NRCS) Web Soil Survey for Payne County was used to broadly assess the soils within the proposed action area. Most of these soil units are considered well drained and formed from weathered sandstone. Multiple soil series are located within the proposed project area and are listed below:  Pulaski fine sandy loam, 0 to 1 percent slopes, frequently flooded  Norge loam, 3 to 5 percent slopes, eroded  Ashport silty clay loam, 0 to 1 percent slopes, occasionally flooded  Easpur loam, 0 to 1 percent slopes, occasionally flooded  Grainola-Ashport frequently flooded  Mulhall complex, 0 to 8 percent slopes 5.3.1.1 Farmland Soils The Natural Resource Conservation Service (NRCS) administers the Farmland Protection Policy Act (FPPA 1981) to ensure that federal programs minimize unnecessary and irreversible conversion of farmland soils to nonagricultural uses. The National Resources Conservation Service Stillwater office was contacted with regard to any impacts the proposed project may have on farmland soils. Documentation is provided in Appendix B. Direct Impacts The proposed action alternative will directly impact approximately 4.60 acres of soil. The NRCS stated ‘the project does include prime farmland soils as defined by the Farmland Protection Policy Act. However, since the work is short term and land will be restored and not converted, this will be considered as no impact. If the project crosses or disturbs any existing conservation practices on private lands, repairs may be needed to restore impacted practices back to preexisting conditions.’ Construction of the proposed action will be performed in accordance with the standard best management practices (BMP’s) employed to minimize soil erosion and sedimentation from exposed soils. Temporary soil disturbance will occur associated with utility line trench excavation operations. All trenches will be backfilled upon line installation and the affected areas returned to original contour and elevation. Indirect Impacts Indirect impacts to surface waters could result from waterborne soil loss attributed to the proposed action. Silt fencing, hay bale barriers or other sediment trapping devices would be installed down gradient of areas of disturbance to dissipate velocities of surface water runoff and trap fugitive sediment. All disturbed soils will be re- vegetated upon progressive completion of the project. 5.3.2 Vegetation The U.S. Fish and Wildlife Service (USFWS) defines an ecosystem as a geographic area and all its living components, their physical surroundings, and the natural cycles that sustain them. The project area is located within the Northern Cross Timbers ecoregion. The hills, cuestas, and ridges of the Northern Cross Timbers are naturally covered by a mosaic of oak savanna, scrubby oak forest, eastern redcedar, and tall grass prairie. Native on porous, course-textured soils derived from sandstone are post oak, blackjack oak, and understory grasses. Tall grass prairie naturally occurs on fine-textured soils derived from sandstone or shale. (Woods et.al., 2005). The construction corridors transitions across open fields used for hay production, tilled agriculture fields, and a previously cleared riparian zone associated with the Boomer Creek floodplain. The dominant vegetation observed Dallis grass (Paspalum distichum), common ragweed (Ambrosia artemisifolia), great ragweed (A. trifida) fescue (Festuca pratensis), Bermuda grass (Cynodon dactylon), Spanish needles (Bidens bipinnata), Johnson grass (Sorghum halapense), crab grass (Digitaria sanguinalis), brome (Bromus sp.), beggar’s lice (Torrillis arvensis), frost weed (Verbesina virginica), purple top (Tridens flavus), and bristle grass (Setaria sp.) and green briar (Smilax rotundifolia). Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 18 Trees within the riparian zone included American elm (Ulmus americana), hackberry (Celtis occidentalis), Osage orange (Maclura pomifera), cottonwood (Populus deltoides), and oak species (Quercus). Direct Impacts Removal of herbaceous and woody vegetation would result from the proposed action. Revegetation of the disturbed areas within the proposed action area is proposed as compensatory mitigation to restore the affected areas of vegetation (Section 6.0). No invasive or noxious species as identified on the Oklahoma Invasive Plants Watch List were observed within the action area during the onsite field surveys. The most current list of invasive species is provided in Appendix B. Care should be taken by the selected contractor to ensure the vegetation used to restore exposed soils upon construction is free of noxious plant seed or stock. Indirect Impacts Indirect impacts to vegetation are not anticipated. However, if resulting adverse effects to vegetation are discovered upon project completion, the City will evaluate the potential solutions to rectify incidental affects to the extent possible. 5.4 WATER & RELATED RESOURCES Surface Water The Stillwater South US Geological Survey (USGS) topographic map and aerial imagery of the project area were initially reviewed to identify surface water resources with the action area. The topographic map indicated two intermittent streams bisect the action area, Boomer Creek and an unnamed tributary to Stillwater Creek. The locations, descriptions, and characterizations of the identified aquatic resources are provided in the waters of the US Delineation report of survey located at Appendix C. Based on a Water’s of the United States (WOUS) Delineation survey performed by EEC, Boomer Creek would be affected by the proposed inverted siphon structure crossing. Boomer Creek is accurately classified as intermittent however the unnamed tributary is more indicative of an ephemeral drainage. Additionally, the proposed South Interceptor would cross one unnamed tributary to Stillwater Creek. No perennial streams or wetland areas are present in the action area. The project area lies within the Boomer and Stillwater Creek Watershed of the Cimarron River drainage basin. None of the identified aquatic resources are shown as impaired waterways. Potential erosion control and stormwater management concerns have been identified and will be addressed through development and implementation of a Storm Water Pollution Prevention Plan as required by Section 402 of the Clean Water Act. The project engineer will prepare and provide said plan to the contractor to avoid and minimize potential impacts to water quality. Direct Impacts The proposed South Interceptor Inverted Siphon Structure would be installed across Boomer Creek using conventional trenching techniques. Similarly, the crossing of the unnamed tributary to Stillwater Creek would also be accomplished using trenching methodology. Said crossings would require Section 404 permit authorization from the USACE. Based on the expected impacts and quantities of fill material to be discharged into Boomer Creek and unnamed tributary to Stillwater Creek would meet the scope of the Nationwide Permit (NWP) for Utility Lines. The City submitted the Section 404 permit and jurisdictional determination request letter to the USACE January 2021. The WOUS delineation report, biological assessment, and cultural resources study report were provided to the USACE as part of the permit request as required by Pre-Construction Notification conditions of the NWP. The USACE provided an official determination of jurisdiction and authorized the proposed creek crossings under the NWP for Utility Lines. A copy of the official permit authorization letter received from the USACE is provided in Appendix B. Indirect Impacts The proposed action may cause temporary minor increases in turbidity to surface water resources during construction. The stormwater pollution prevent plan will incorporate silt fencing and hay bale barriers or similar measures to be installed down gradient of disturbed soil areas to dissipate velocities of surface water runoff and trap waterborne sediment. Groundwater The Oklahoma Department of Environmental Quality (ODEQ) data viewer was used to broadly assess groundwater resources beneath land within the proposed action. No major or minor aquifers are present beneath the action Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 19 area. Unnamed, consistent or inconsistent ground water resources are anticipated to be shallow and likely obtained within the sandstone units the Quarternary alluvium bands. Direct Impacts The proposed action will result in minimal disturbance of land within the local watershed or underlying aquifer. The change in land use associated with this project should have a negligible, if any, effect on groundwater recharge. Indirect Impacts No indirect impacts are expected due to the shallow excavation of utility line trenches. All trenches will be backfilled without using impervious materials and groundwater flow patterns should return to pre-disturbance conditions. Public Water Supplies The ODEQ data viewer was used to identify the presence of public water supplies wells, public water supply intakes, and wellhead protection areas that could be affected by the proposed action. Direct Impacts No public water supply intakes or systems are present within or near the proposed action area and no direct impacts are expected. Indirect Impacts Based on no evidence of public water supply systems or facilities, no indirect impacts are expected. Scenic River Areas The proposed action is not located within a county (Adair, Cherokee, Delaware, Sequoyah or McCurtain) that contains scenic waters. Direct Impacts No impacts to scenic river areas would occur. Indirect Impacts No indirect impacts to scenic river areas would occur. Sole Source Aquifers The ODEQ data viewer was accessed to identify the location of any sole source aquifers in Oklahoma. No sole source aquifers are located within or near the proposed action area. Direct Impacts No direct impacts to sole source aquifers should occur. Indirect Impacts No indirect impacts to aquifers are anticipated. 5.4.1 Floodplains The protection of floodplains and floodways is required by Executive Order 11988 to avoid to the extent possible the long and short-term adverse impacts associated with the occupancy and modification of floodplains to avoid direct or indirect support of floodplain development. Coordination with the City of Stillwater and Payne County Floodplain Administrators confirmed the proposed action would be located within floodway and floodplain areas. The floodway and floodplain boundaries are shown on Figure 3. The proposed action is located on the Federal Emergency Management Agency’s (FEMA) Flood Insurance Rate Map Number 40119CO235F map panel dated May 16, 2007. Direct Impacts The project would involve burial of the proposed utility lines and not result in the restriction or displacement of floodplains. No direct impacts are anticipated from the proposed action. All work associated with the proposed action would conform to applicable state or local floodplain protection standards. Best management practices will Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 20 keep disturbance to a minimum. The City or their selected contractor will prepare and submit a completed application for a Floodplain Development Permit to the Payne County Floodplain Administrator. A Notice of Intent will be completed and provided to the ODEQ prior to construction. Indirect Impacts No indirect impacts are anticipated or have been identified. 5.4.2 Wetlands The USACE Wetlands Delineation Manual (Environmental Laboratory, 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Great Plains Region (USACE 2010) were referenced in concert to identify wetlands within the action area. Wetland areas, if observed, were to be identified using the routine on- site (level 2) method, as described in Section D of the 1987 USACE Wetlands Delineation Manual. The identification of wetlands consists of a three-parameter approach that involves determining the presence of hydrophytic vegetation, hydric soils, and wetland hydrology. EEC performed a WOUS and wetland delineation survey within the proposed action area and the report of survey is provided in Appendix C. Direct Impacts No wetland areas were identified or delineated within the proposed action corridors No wetlands would be affected. Indirect Impacts No indirect impacts are expected to occur in wetland areas resulting from the proposed action. 5.5 FISH AND WILDLIFE The species of wildlife expected to use or be present within the proposed action area may include such species as white-tailed deer (Odocoileus virginianus), fox squirrel (Sciurus niger), cottontail rabbit (Sivilagus floridanus), raccoon (Procyon lotor), mink (Mustela vison), opossum (Didelphis virginiana), skunk (Mephitis mephitis), and beaver (Castor canadensis). Various avian species comprised of raptors, waterfowl, neo-tropical migrants, as well as a variety of herpetofauna including timber rattle snakes (Crotalus horridus), copperhead (Agkistrodon contortrix), water snakes (Nerodia sp.), amphibians, salamanders, lizards, skinks, tortoise and turtles are present in and/or migrate through the general area. Predatory mammals including the coyote (Canis latrans) are expected in average density while the numbers of grey fox (Urocyon cinereoargenteus) are expected to be low despite the presence of suitable habitat. Local bobcat (Lynx rufus) populations are anticipated to be below average. The typical fish species that may use the local water resources within the project area can include sunfish, catfish, and forage species including minnows and shiners. Small populations of game, forage, and rough fish are expected within Boomer Creek but their presence is anticipated to be a function of water levels exhibited during construction periods. The proposed action construction period is anticipated to occur in the summer of 2021 during periods of low water flows/levels. Direct Impacts Direct Impacts to fish and wildlife are considered to be short term, localized and cease when the proposed action is completed. Animal species and their respective uses are expected to be varied, opportunistic, and relative to the preferred or utilized habitats for each. Based on the observed habitat characteristics, the most predominant species expected to be present or utilize the proposed action would consist of small mammals and birds. The diversity of bird species varies between summer and winter migrants however, no nests were observed during the initial field surveys. Predatory or omnivorous animals such as coyote, skunk, raccoon, and snakes are expected to utilize both areas primarily during foraging. The habitat quality is subjectively described as fair to excellent relative to the wide range of species known to occur within or adjacent to the project area. For example, white-tailed deer may use the area for cover and foraging due to its seclusion, restricted access, and vegetative structure. Fox squirrels are expected to be present in average numbers based on the presence of hard-mast bearing trees. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 21 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 22 Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 23 Avian species utilize the action area and appear to be relegated primarily to neo-tropical migrants. However, raptorial birds such as hawks and owls can effectively use the open, forested, and/or transition areas for hunting. Suitable nest trees are present within the action area and associated with the riparian zone of Boomer Creek. Other nest trees were observed adjacent to the action area as well. Ground nesting species were not observed and are not expected in any consistent appreciable extent or numbers due to the current land use practices removing or disturbing herbaceous vegetation. Ground-dwelling rodents and their evidence were observed within the action area. Suitable forage and cover is provided by deadfall, vines, and seed producing herbaceous vegetation. Approximately 0.25 acres of tree removal would occur on the north side of the previously cleared corridor along the existing South Interceptor west of the inverted siphon structure. Herpetofauna are expected throughout the action area but their presence and abundance will be predicated on the specific habitats along the action area corridor. Habitats providing multiple vegetative strata may be more utilized by herpetofauna as opposed to open herbaceous fields used for hay production or bio-solids injection. Further, their presence would also be a function of the species and forage requirements. The overall impacts to terrestrial species are expected to be minor and temporary. The majority of the terrestrial species should be able to flee the proposed work areas prior to construction. Some nesting habitat for avian species may be removed. Impacts to fish and wildlife species overall are expected to be minor and temporary. However, more than sufficient areas of suitable and/or preferred habitat is available adjacent or in very close proximity to the proposed action area for terrestrial species to utilize for cover, nesting, denning, and/or foraging. Suitable habitat for escaping aquatic species is also present immediately up and downstream of the Boomer Creek crossing. Indirect Impacts Indirect impacts could result to fish and wildlife during temporary displacement or vacating the construction corridors while fleeing species relocate to alternatively undisturbed areas. Similarly, indirect impacts may occur during the period required for disturbed soils to become revegetated. 5.5.1 Threatened and Endangered Species In accordance with the Endangered Species Act of 1973, federal agencies are required to consult and/or coordinate with the USFWS to address potential impacts to federally-listed threatened and endangered (T&E) species relative to a proposed action. EEC initiated said coordination on behalf of the City and acquired the official list of T&E species which could be present in or migrate through the proposed action area. EEC subsequently conducted field surveys to identify and characterize exhibit habitats and determine potential impacts relative to the listed species and prepared a biological assessment (BA) located in Appendix D. The BA was provided to the USACE to facilitate their review and compliance with Section 7 of the Endangered Species Act as part of the Section 404 of the Clean Water Act permit review process. The USACE was considered the federal agency responsible for this coordination and as such would initiate Section 7 consultation with the U.S. Fish and Wildlife Service (USFWS) as required on behalf of the City and OWRB. The official list of threatened and endangered species potentially present within or adjacent to the proposed action was obtained from the USFWS Information, Planning, and Conservation (IPaC) decision support system (Appendix B) and the excepted species list is shown in Table 3. Additionally, EEC contacted the Oklahoma Biological Survey and requested species of concern occurrence records information. No known or recorded species occurrences were identified within the proposed action area. Documentation is provided in Appendix B. Table 3 - Federally Listed T&E Species Species/Critical Habitat Listing Status Habitat Requirements Status within Action Area Designated Critical Habitat within Action Area Least Tern (Sterna antillarum) Endangered (Proposed Downlisting) Islands or sandbars along large rivers, mostly clear of vegetation for nesting and loafing and with shallow water nearby for fishing. No suitable habitat present within action area. No Piping Plover (Charadruis melodus) Threatened Migratory stopover habitat includes sparsely vegetated sandy or gravelly shorelines and islands associated with the major river systems. Species does not nest in OK. No suitable habitat present within action area. No Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 24 Table 3 - Federally Listed T&E Species Species/Critical Habitat Listing Status Habitat Requirements Status within Action Area Designated Critical Habitat within Action Area Red Knot (Calidris canutus rufa) Threatened Coastal areas, mudflats on lakes or reservoirs, and may use sandbars along the major river systems for forage and resting areas. Species does not nest in OK. No suitable habitat present within action area. No Whooping Crane (Grus americana) Endangered Breeds in Wood-Buffalo National Park, Canada; Migratory stopover habitat include rivers, wetlands, salt marshes, and tidal flats on mainland and barrier islands along the Gulf of Mexico. Exposed salt marshes, rivers, or tidal flats to provide habitat. No suitable habitat present within the action area. No American Burying Beetle (Nicrophorus americanus) Threatened Breeding habitat: undisturbed, mature oak-hickory forests with substantial litter layers and deep, loose soils over grasslands or bottomland forests. Feeding habitat: undisturbed grasslands, grazed pasture, riparian zones, and oak-hickory forest, as well as a variety of various soil types. Suitable habitat present within project area associated with Boomer Creek riparian zone. Remainder of action area not identified as exhibiting suitable habitat. Section 4(d) Rule applied to address potential take, no ABB surveys required/conducted. No USFWS, 2020 American Burying Beetle The proposed action lies within the historic range of the ABB. The majority of the habitats identified within the action area did not exhibit suitable ABB habitat characteristics. However, potentially suitable habitat was observed within the forested riparian zone adjacent to Boomer Creek on the north side of the previously cleared corridor associated with the existing South Interceptor line. No ABB surveys were conducted. Based on the recent down-listing of the ABB from endangered to threatened and the development of effects determination keys under Section 4(d) of the ESA, it was determined no surveys would be required and the proposed action would result in a No Effect determination. The USACE concurred with said determination and coordinated with the USFWS for official concurrence prior to completion of the Section 404 permit review process. Least Tern The migration corridor for least terns encompasses the State of Oklahoma and is known to utilize the Cimarron River in southern Payne County. Terns use suitable aquatic resources for nesting or temporary stopovers. Based on the biological assessment, the aquatic resources within or immediately adjacent to the action area do not provide suitable habitat for the Least Tern. The proposed action would have a No Effect determination for the Least Tern Piping Plover Similar to the least tern, piping plovers transition across Oklahoma during migration and use suitable aquatic resources for temporary stopovers. However, piping plovers do not nest in Oklahoma. The aquatic resources within or immediately adjacent to the project area do not provide suitable habitat for the piping plover and the proposed action would have No Effect on this species. Red Knot This species migrates through Oklahoma in the spring and fall. Migratory habitat requirements for the red knot include coastal areas, mudflats on lakes or reservoirs, and may use sandbars along the major river systems for forage and resting areas. No suitable aquatic resources were identified within or immediately adjacent to the action area. The proposed action would have a No Effect determination for the red knot. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 25 Whooping Crane Whooping cranes migrate across Oklahoma in the spring and fall between Canada and the Texas coast line near Port Aransas on Gulf of Mexico. No suitable habitats for this species were identified the action area. The project would have a No Effect determination for the whooping crane. The Species Conclusion Table (Table 4) below provides the documentation and rationale relative to the potential affect to each of the federally-listed species: Table 4 – T&E Species Conclusion Table Species/Critical Habitat Habitat Presence Determination USFWS Consultation ESA Determination Least Tern No Suitable Habitat Present Not Required No Effect Piping Plover No Suitable Habitat Present Not Required No Effect Red Knot No Suitable Habitat Present Not Required No Effect Whooping Crane No potential habitat present Not Required No Effect American Burying Beetle Potentially Suitable Habitat Required No Effect Bald Eagle Although the Bald Eagle (Haliaeetus leucocephalus) has been removed from the threatened and endangered species list, the eagle continues to be protected by the Bald and Golden Eagle Protection Act. The bald eagle prefers large trees or high cliffs along large waterways for perching and nesting purposes. Fish are the preferred diet of eagles, but they also eat small mammals, waterfowl, turtles and dead animals. Preferred foraging areas include quiet coastal areas, rivers or lakeshores with large tall trees. Direct Impacts Potential or suitable habitat was not identified within the action area for the bald eagle. No bald eagles or nests were observed during the site visit. This project is not expected to directly affect the bald eagle. Indirect Impacts No indirect impacts to the bald eagle have been identified or are anticipated. Migratory Birds Migratory bird species are protected under the Migratory Bird Treaty Act (MBTA) as amended. The MBTA prohibits the take of any migratory bird without authorization for the USFWS. Suitable nesting habitats within the action area appeared to be primarily associated with forested areas exhibiting functional and undisturbed habitat components. The primary species potentially nesting in said areas may include perching birds, neo-tropical migrants, turkey, cranes, egrets, and/or raptors. While potentially suitable nesting habitat was present, no bird nests were observed within the action area during biological assessment field surveys. Direct Impacts Suitable nesting habitat is present within the project area primarily associated with the Boomer Creek riparian zone. The herbaceous open field areas did not exhibit suitable nesting habitat based on the routine land use activities and observed, near mono-typic, plant species assemblages. No bird nests were observed within the action area. No active swallow nests were observed within the action area. Construction is encouraged to occur between August 15 and March 31 to avoid the nesting season to avoid potential impact to migratory birds. Suitable habitat for non- migratory ground nesting birds may be minimally present but is anticipated to be restricted to very small patches and/or isolated areas. Adverse impacts to the continued overall existence of populations of multiple various species is not expected. Construction is encouraged to occur during the non-nesting season to minimize potential impacts. Adverse effects could occur to migratory or non-migratory birds associated with tree removal operations within the Boomer Creek riparian zone. The acreage of tree removal would be approximately 0.25 acres resulting in minor potential impacts. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 26 Indirect Impacts Indirect impacts to raptorial birds could occur from the temporary displacement of forage species vacating the immediate construction corridors. However, sufficient hunting habitat for these birds is present immediately adjacent to the action area. Temporary impacts to herbaceous habitats may affect the foraging and/or nesting patterns of bird species within the narrow construction corridor. However, based on the low density of only marginally suitable habitat which could be utilized, adverse impacts to these bird species are not anticipated. 5.6 CULTURAL RESOURCES Section 106 of the National Historic Preservation Act of 1966 (Section 106), as amended, protects those properties that are listed or eligible for listing in the National Register of Historic Places (NRHP). In Oklahoma, the State Historic Preservation Office (SHPO) includes two entities that share responsibilities for Section 106 coordination; the Oklahoma Archeological Survey (OAS) and Oklahoma Historical Society (OHS). 5.6.1 SHPO Consultation EEC provided scoping letters to the OAS and OHS to determine the need for cultural resource surveys. OAS stated a field archeological survey would be required in areas where the proposed utility lines would potentially affect areas that were not previously disturbed. OHS did not provide a response letter. A cultural resource survey was subsequently performed in October 2020 during which no cultural resources considered to be potentially eligible for the National Register of Historic Places were identified. The report of survey is not included in the EID due to concerns of disseminating potentially sensitive information as required by the respective agencies and/or tribal nations. Section 106 consultation with the both OAS and OHS was conducted by the OWRB. Completion of said coordination provided concurrence from both agencies the proposed project would not affect any historic properties or cultural resources. Documentation is provided in Appendix B. Direct Impacts Based on the results of the field archeological survey and concurrence of findings received from OAS and OHS, no direct impacts to cultural resources or historic properties would occur. Indirect Impacts No indirect impacts have been identified or are expected. 5.6.2 Tribal Consultation The Bureau of Indian Affairs was contacted concerning any Native American Tribal interest of the proposed action area. Additionally, the U.S. Department of Housing and Urban Development Tribal Directory Assessment Tool (TDAT) was used to identify Native American Tribes that may have an interest in the proposed action area. Nine native American Indian tribes were provided scoping letters relative to the proposed action as listed below:  Alabama-Quassarte Tribal Town  Apache Tribe of Oklahoma  Cheyenne and Arapaho Tribes of Oklahoma  Caddo Nation of Oklahoma  Muscogee (Creek) Nation  Osage Nation  Otoe-Missouria Tribe  Quapaw Tribe of Indians  Chickasaw Nation  Wichita and Affiliated Tribes (Wichita, Keechi, Waco, & Tawakonie) Only the Quapaw Nation and Otoe-Missouria Tribe, provided a response to the proposed project stating the project area was outside their area of interest and they elected to abstain from providing comments. Documentation is provided in Appendix B. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 27 Direct Impacts No comments or concerns relative to potential affects to tribal resources were received. No tribally-sensitive materials were identified or discovered during the field archeology survey. No direct impacts to resources of Native American tribal concern are expected. Indirect Impacts No indirect impacts are expected. 5.7 AIR QUALITY The Clean Air Act (CAA) requires the USEPA to identify National Ambient Air Quality Standards (NAAQS) to protect public health and welfare. Ambient air quality monitoring stations exist at various locations throughout Oklahoma. The NAAQS were established for ozone (O3), carbon monoxide (CO), nitrogen dioxide (NOx), sulfur dioxide (SOx), and particulate matter (PM10) and (PM 2.5). Areas that meet the national standards for the criteria air pollutants are in attainment. Areas that exceed the national standards are in nonattainment. Under the CAA, the EPA has classified air basins as being in attainment or nonattainment for each of the criteria pollutants and whether or not the standards have been achieved. Air quality in Oklahoma is measured and regulated by the Oklahoma Department of Environmental Quality, Air Quality Division (Table 5). Currently, Payne County, Oklahoma is in attainment with regard to the NAAQS with respect to the criteria pollutants CO, SO2, O3, NO2.5, PM10, and Pb (Ashford, 2018). Additionally, the Environmental Protection Agency’s Green Book website was used to assess the air quality in Oklahoma. The Green Book shows no areas of nonattainment for Criteria Pollutants in Oklahoma (EPA, 2018). Payne County is in attainment for the NAAC pollutants. Table 5 - National Ambient Air Quality Standards Pollutant Primary/Secondary Averaging Time Level Carbon Dioxide Primary 8-hour 9 ppm 1-hour 35 ppm Lead Primary and Secondary Rolling 3-month avg 0.15µg/m3 (1) Nitrogen Dioxide Primary 1-hour 100 ppb Primary and Secondary Annual 53 ppb (2) Ozone Primary and Secondary 8-hour 0.070 ppm (3) Particulate Pollution PM 2.5 Primary Annual 12 µg/m3 Secondary Annual 15 µg/m3 Primary and Secondary 24-hour 35 µg/m3 PM 10 Primary and Secondary 24-hour 150 µg/m3 Sulfur Dioxide Primary 1-hour 0.075 ppb(4) Secondary 3-hour 0.5 ppm (1) In areas designated nonattainment for the Pb standards prior to the promulgation of the current (2008) standards, and for which implementation plans to attain or maintain the current (2008) standards have not been submitted and approved, the previous standards (1.5 µg/m3 as a calendar quarter average) also remain in effect. (2) The level of the annual NO2 standard is 0.053 ppm. It is shown here in terms of ppb for the purposes of clearer comparison to the 1- hour standard level. (3) Final rule signed October 1, 2015, and effective December 28, 2015. The previous (2008) O3 standards additionally remain in effect in some areas. Revocation of the previous (2008) O3 standards and transitioning to the current (2015) standards will be addressed in the implementation rule for the current standards. (4) The previous SO2 standards (0.14 ppm 24-hour and 0.03 ppm annual) will additionally remain in effect in certain areas: (1) any area for which it is not yet 1 year since the effective date of designation under the current (2010) standards, and (2)any area for which an implementation plan providing for attainment of the current (2010) standard has not been submitted and approved and which is designated nonattainment under the previous SO2 standards or is not meeting the requirements of a SIP call under the previous SO2 standards (40 CFR 50.4(3)). A SIP call is an EPA action requiring a state to resubmit all or part of its State Implementation Plan to demonstrate attainment of the required NAAQS. Source: USEPA Office of Air and Radiation, 2016. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 28 Direct Impacts Construction Related Emissions The proposed project could generate local temporary short-term direct impacts on air quality during construction. Sources of dust could also be generated from vehicular traffic and construction-related equipment during operation. The implementation of the following recommendations regarding the construction period of the project include:  Use ultra-low sulfur fuel ( 15 ppm) in all diesel engines.  Use add-on controls such as catalysts and particulate traps where suitable.  Minimize engine idling (e.g., 5-10 minutes/hour).  Use equipment that runs on clean, alternative fuels as much as possible.  Use updated construction equipment that was either manufactured after 1996 or retrofit to meet the 1996 emissions standards.  Prohibit engine tampering and require continuing adherence to manufacturers’ recommendations.  Maintain engines in top running condition tuned to manufacturers’ specifications.  Phase project construction to minimize exposed surface areas.  Reduce speeds to 10 and 15 mpg in construction zones.  Conduct unannounced site inspections to ensure compliance.  Locate haul truck routes and staging areas away from sensitive population centers. Payne County is classified as in attainment with regard to the NAAQS pollutants. The emission levels of the anticipated construction equipment are expected to be minimal based on the relatively few numbers of construction equipment needed to accomplish the construction process and the EPA-mandated emission control systems required on said equipment. Minor increases may result during times where simultaneous operation of multiple types of equipment occur. However, these periods are expected to be periodic allowing sufficient time for atmospheric assimilation and should not result in adverse air quality situations. The project owner or their selected contractors will implement dust control measures that will effectively eliminate and or minimize dust during construction activities. No long term or adverse impacts are anticipated Operational Related Emission Criteria emission sources during proposed action operation would not occur. Indirect Impacts No indirect impact to air quality is anticipated. 5.8 HAZARDOUS WASTE - ENVIRONMENTAL DUE DILIGENCE A hazardous materials assessment was also performed by EEC within the proposed action area and also included the standard search radii for any known recognized environmental conditions. Environmental Data Resources, Inc (EDR) was utilized to ascertain the state, federal, and tribal database information to facilitate the hazardous material assessment. No hazardous, toxic, or radiologic waste sites were identified within the project study corridor through EDR. No regulated facilities were identified or observed within or near the proposed action area. No stained soil or distressed vegetation was observed within the survey corridor. The hazardous material assessment report is provided at Appendix D. Direct Impacts Construction of the proposed action would not result in direct impacts on or disturbance to any known hazardous, toxic, or radiological wastes. Indirect Impacts Indirect impacts could result from the operation of construction equipment or storage of equipment, fuels, or lubrication products. Accidental spills of petroleum products or hazardous materials spills could also occur. The City will require all contractors to prepare and implement an operational and storage plan to prevent such leakage or spills and to report any such occurrence immediately upon notice. The contractors will be made responsible for prevention measures as well as cleanup and/or removal of such spillage as well as properly handling/disposing of contaminated soils, as deemed necessary by City. Environmental Information Document/Environmental Report City of Stillwater - South Interceptor, Inverted Siphon Structure, and 10-inch Connector Line. Project P a g e | 29 5.9 GEOLOGY The proposed action area is located in the Central Red-bed Plains Geomorphic Province of Oklahoma (Curtis and Hamm, 1979) comprised of Permian red shales and sandstones with coarse and fine-grained soils on gently rolling hills and flat plains. The Oklahoma Department of Environmental Quality (ODEQ) data viewer was utilized to further identify geologic strata and description. The action area is located within the Quarternary Alluvium predominantly comprised of sand, silt, clay, and gravel. Thickness ranges from 30 to 80 feet along major streams and from 0 to 60 feet along minor streams. the Bedrock encountered during geotechnical soil borings consisted predominantly of sandstone with shale seams that present little issues toward construction of the proposed action (Tetra Tech, 2018). Direct Impacts Although shallow rock strata may be directly disturbed by the proposed action this would not create any long-term impacts to the geologic environment. Indirect Impacts No indirect impacts are expected from the construction of the proposed action. 5.10 CLIMATE CHANGE Climate change is an important national and global concern. There is general agreement that the earth’s climate is currently changing and anthropogenic (human-caused) greenhouse gas (GHG) emissions have been documented as contributing to this change. Carbon dioxide (CO2) makes up the largest anthropogenic component of these GHG emissions. However, there is no scientific methodology for attributing specific climatological changes to a particular project’s emissions. The CEQ GHG emissions guidance requires action agencies to consider: (1) The potential effects of a proposed action on climate change as indicated by assessing GHG emissions (e.g., to include, where applicable, carbon sequestration); and, (2) The effects of climate change on a proposed action and its environmental impacts. This guidance recommends agencies quantify a proposed agency action’s projected direct and indirect GHG emissions; use projected GHG emissions (to include, where applicable, carbon sequestration implications associated with the proposed agency action) as a proxy for assessing potential climate change effects; recommends agencies include a qualitative analysis and explain the basis for determining that quantification is not reasonably available because tools, methodologies, or data inputs are not reasonably available to support calculations for a quantitative analysis; discusses methods to appropriately analyze reasonably foreseeable direct, indirect, and cumulative GHG emissions and climate effects; considers reasonable alternatives for short- and long-term effects and benefits in the alternatives and mitigation analysis; advises agencies to use available information rather than undertaking new research, and provides examples of existing sources of scientific information; recommends using information developed during the NEPA review to consider alternatives that would make the actions and affected communities more resilient to the effects of a changing climate; outlines special considerations fo