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Home My WebLink AboutDSHW-2024-005371 Mitigation and Restoration Plan Reroute of Segment 2B Part 2 Northwest Oil Drain Canal Davis County, Utah March 2014 Submitted to: Mr. Galen Williams EarthFax Engineering 7324 South Union Park Ave. Suite 100 Midvale, Utah 84047 Submitted by: BIO-WEST, Inc. 1063 W. 1400 N. Logan, Utah 84321 www.bio-west.com BIO-WEST, Inc. Northwest Oil Drain March 2014 i Mitigation and Restoration Plan TABLE OF CONTENTS Introduction and Background ......................................................................................................... 1 Affected Environment ................................................................................................................. 1 Project Impacts............................................................................................................................ 5 Proposed Mitigation ........................................................................................................................ 7 Permanent Impacts ...................................................................................................................... 7 Temporary Wetland Impact Mitigation ...................................................................................... 7 Upland Restoration ..................................................................................................................... 8 Monitoring .................................................................................................................................. 9 Weed Treatment .......................................................................................................................... 9 References ..................................................................................................................................... 10 APPENDIX A: NORTHWEST OIL DRAIN CANAL SEGMENT 2B PART 2 REROUTE TYPICAL CROSS SECTION APPENDIX B: MACHINE LAKE WETLAND MITIGATION BANK INFORMATION List of Tables Table 1. Proposed Saline Wet Meadow Seed Mix. .................................................................... 8 Table 2. Proposed Upland Seed Mix. ......................................................................................... 8 List of Figures Figure 1. Northwest Oil Drain Canal Segments 1–3 Vicinity Map. ............................................ 2 Figure 2. Northwest Oil Drain Canal Segment 2B Site Map. ...................................................... 3 Figure 3. Northwest Oil Drain Canal Segment 2B Part 2 Reroute Wetland Impacts Map. ......... 4 BIO-WEST, Inc. Northwest Oil Drain March 2014 1 Mitigation and Restoration Plan INTRODUCTION AND BACKGROUND The Northwest Oil Drain Canal (NWOD) is an open ditch that conveys treated wastewater effluent and stormwater from Salt Lake City, Utah, to the Great Salt Lake. Beginning in the early 1900s, several oil refineries and a railroad maintenance facility discharged wastewater into the NWOD. As a result, hydrocarbon-impacted sediments have accumulated in the substrate of the canal. The NWOD Working Group (composed of Salt Lake City Corporation, BP Products North America, Inc., and Chevron USA, Inc.) performed an initial dredging effort between 2004 and 2006, and removed approximately 75,000 tons of impacted sediment from the NWOD (ERM 2007). Following the initial cleanup, the NWOD contained residual sediment ranging in thickness from a few inches to 4 feet. Under a second cleanup effort, the NWOD Working Group has successfully removed this residual sediment from the first 1.4 miles of the NWOD, designated as Segments 1 and 2A (Figure 1). BIO-WEST, Inc. (BIO-WEST) was retained by EarthFax Engineering, Inc. (EarthFax) to provide a wetland mitigation plan for impacts associated with the reroute around Segment 2B Part 2 of the NWOD in Davis County, Utah (Figure 2). The reroute around this segment is necessary to (1) mitigate slope stability hazards, (2) separate surface water from hydrocarbon impacts associated with Chevron Product Company’s (Chevron’s) Oily Dump Wedge (DOF 2013), (3) allow access to the Oily Dump Wedge canal for mitigation by Chevron at a later date, and (4) because effective implementation of the canal cleanup under the Administrative Order on Consent, including removal of sediments and prevention of recontamination, could not be achieved by maintaining the canal in its current alignment. The Oily Dump Wedge is a future cleanup site associated with the historic operation of the Oily Dump waste ponds, which were located immediately east of the existing NWOD. Affected Environment The project area consists of the existing Segment 2B Part 2 of the NWOD, the planned rerouted segment of the NWOD, temporary soil stockpile areas, and temporary construction access areas. The planned rerouted portion around Segment 2B Part 2 is located west of the existing NWOD and east of Redwood Road on property owned by Chevron. A typical cross section of the rerouted canal area is included as Appendix A. The project area wetlands were delineated by BIO-WEST in September 2011 and March 2013 (Figure 3). The wetlands were delineated under the guidance provided by the U.S. Army Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987), Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (Research and Development 2008), National List of Plant Species that Occur in Wetlands: 1988 National Summary (USFWS 1988), and North American Digital Flora: National Wetland Plant List (Lichvar and Kartesz 2009). The wetland delineation findings were verified by the U.S. Army Corps of Engineers on June 25, 2013 (U.S. Army Corps of Engineers #SPK-2013_00134-UO). Project area wetland communities include saline wet meadow and iodine bush (Allenrolfea occidentalis) shrub scrub. The project area also contains numerous canals and ditches that were mapped as part of the wetland delineation field work. BIO-WEST, Inc. Northwest Oil Drain February 2014 2 Mitigation and Restoration Plan Figure 1. Northwest Oil Drain Canal Segments 1–3 Vicinity Map. BIO-WEST, Inc. Northwest Oil Drain February 2014 3 Mitigation and Restoration Plan Figure 2. Northwest Oil Drain Canal Segment 2B Site Map. BIO-WEST, Inc. Northwest Oil Drain February 2014 4 Mitigation and Restoration Plan Figure 3. Northwest Oil Drain Canal Segment 2B Part 2 Reroute Wetland Impacts Map. BIO-WEST, Inc. Northwest Oil Drain March 2014 5 Mitigation and Restoration Plan Saline wet meadow is the dominant wetland type within the project area. This vegetation community is dominated by inland saltgrass (Distichlis spicata), with other interspersed nondominant species including alkali weed (Cressa truxillensis) and Arctic rush (Juncus arcticus). The saline wet meadow community is seasonally flooded in the spring and early summer, then dries down in late summer and fall. The soils are hydric, indicating prolonged periods of surface water inundation or subsurface saturation between the soil surface and 12 inches below the soil surface during the growing season. At the time of the 2011 wetland delineation the project area contained an iodine bush shrub scrub wetland community. This community is slightly higher in elevation than the surrounding saline wet meadow, allowing the limited growth of small shrubs. The dominant species is iodine bush with other interspersed nondominant species including black greasewood (Sarcobatus vermiculatus), inland saltgrass, and alkali weed. The iodine bush shrub scrub community is seasonally flooded in the spring and dries down in summer and fall. The soils are hydric, indicating prolonged periods of surface water inundation or subsurface saturation between the soil surface and 12 inches below the soil surface during the growing season. The iodine bush shrub scrub community within the project area was delineated in September 2011, following a higher-than-average winter snowpack and wetter-than-average spring. At the time of the delineation, the iodine bush shrub scrub community was flooded, which would not be considered a normal late-summer or early-fall condition. During the follow-up 2013 site visit, most of the shrubs in the community had died off or appeared stressed, likely due to the wetter- than-average conditions observed in 2011. The wetlands that were classified as iodine bush shrub scrub in 2011 are now dominated by inland saltgrass and are currently more accurately classified as saline wet meadow. The project area wetlands have been historically disturbed and fragmented by agricultural activities, numerous pipeline installations, construction of the Chevron refinery, construction of Interstate 215, construction of Redwood Road, construction of the Bonneville Canal, and construction of the NWOD. Project Impacts The project wetland impacts are illustrated in Figure 3. The project requires permanent wetland impacts to 6.14 acres of saline wet meadow wetlands. The wetland impacts include the excavation of 2,090 linear feet of the rerouted canal through existing wetlands, multiplied by an average reroute width of 128 feet. The average reroute width is defined as the footprint area between the outside toe of slope of the new east service road to the outside toe of slope of the new west service road. This area equals 267,520 square feet of wetlands impacted or 6.14 acres (Figure 3). The 6.14 acres of wetland impacts does not include the filling of the existing Segment 2B Part 2 of the NWOD because the canal is considered a jurisdictional nonwetland water of the United States. The entire length and width of the rerouted canal project, including open water, adjacent flood-control benches, and access roads with associated side slopes on either side of the flood-control benches and canal, were included when calculating wetland impacts. Approximately 1,000 linear feet of the reroute are located in uplands. BIO-WEST, Inc. Northwest Oil Drain March 2014 6 Mitigation and Restoration Plan Following construction cleanup activities, the existing 2,565 linear feet (1.86 acres) of Segment 2B Part 2 of the NWOD will be permanently filled to the adjacent upland access road elevation. There are no wetland impacts associated with cleaning and backfilling the existing Segment 2B Part 2 of the NWOD. The reroute also requires permanent impacts to (0.50 acre) of existing canal/ditch including the abandoned Bonneville Canal and two other unnamed canal/ditches. The existing area of NWOD fill and the permanent impacts to other existing canal/ditch were calculated by EarthFax using AutoCAD. The canal/ditch classification is considered an open water jurisdictional nonwetland water of the United States. The project will result in a net increase in this type of jurisdictional nonwetland water of the United States. The project requires 5.37 acres of temporary impacts to saline wet meadow wetlands and 0.12 acre of unnamed canal/ditch. The temporary impact areas are required for soil stockpile areas and temporary construction access areas associated with the NWOD reroute and the lowering of the airport products pipeline under the NWOD reroute as illustrated in Figure 3. The temporary impacts were calculated by EarthFax using AutoCAD. Potential indirect wetland impacts could include a loss of hydraulic connectivity between adjacent wetlands, freshwater intrusion of saline wetlands, and contamination of adjacent wetlands from nonpoint source pollutants found in canal surface water. Potential nonpoint source pollutants found in the canal surface water could include typical urban runoff from parking lots containing oil and grease, fertilizer and nutrient runoff from adjacent lawns and fields, herbicides used in adjacent lawn maintenance, and sediment from upstream construction activities. To avoid indirect wetland impacts the reroute plan includes an inverted siphon to maintain hydraulic connectivity between adjacent wetlands on both sides of the rerouted canal (Figure 3). The existing water conveyance ditch will also be restored along the west bank of the reroute alignment to ensure hydraulic connectivity remains (Figure 3). The rerouted canal design includes a 15- to 25-foot flood-control bench on either side of the canal and a 14-foot access road with approximately 5 feet of side slope on either side of each flood-control bench, as shown in Appendix A. The road and flood-control bench will prevent the canal from flooding adjacent wetlands during high flows, avoiding the potential of freshwater intrusion and nonpoint source pollutants into the adjacent wetlands. The areas described above as flood-control benches will be returned to preconstruction wetland contours after canal and levee construction are complete. Due to the influence of the adjacent rerouted canal and the influence of the adjacent levees, these wetlands could potentially be indirectly impacted and converted into uplands or into another wetland community type. Due to the uncertain nature of these potential indirect wetland impacts, all of the area between the levees, including the flood-control benches, is considered a permanent direct wetland impact area requiring mitigation. These impacts, along with the impacts associated with the canal open water and the adjacent access roads and side slopes, are included in the permanent-impact acreage of 6.14 acres, presented above. BIO-WEST, Inc. Northwest Oil Drain March 2014 7 Mitigation and Restoration Plan PROPOSED MITIGATION Permanent Impacts The project area wetland impacts are located within the primary service area of the Machine Lake Wetland Mitigation Bank. Consultation with the Machine Lake Wetland Mitigation Bank has been initiated, and it has been determined that the appropriate quantity of wetland mitigation credits to offset project wetland impacts is available for purchase. Due to the primary service area designation and the available mitigation bank credits, a 1:1 wetland impact to mitigation ratio will be applied to the purchase of mitigation bank credits. Chevron plans on purchasing 6.14 acres of saline wet meadow mitigation credits after receiving written approval of this plan of action from the Environmental Protection Agency (EPA). Based on the 2013 observations of dead and/or stressed shrubs in the 0.20-acre project area shrub scrub wetland community, saline wet meadow credits are proposed to mitigate permanent impacts to this area. Information and maps related to the Machine Lake Mitigation Bank and the project area are included as Appendix B. The project includes permanent impacts to 4,015 linear feet (2.35 acres) of canal/ditch which is classified as a jurisdictional nonwetland water of the United States. This includes filling 2,565 linear feet (1.86 acres) of the approximately 32-foot-wide existing section 2B Part 2 of the NWOD, and excavating and/or filling approximately 1,450 linear feet (0.50 acre) of existing canals and roadside ditches required for construction of the reroute. The canals and roadside ditches impacted by the reroute vary in width from approximately 10-feet wide up to approximately 40-feet wide in the case of the abandoned Bonneville Canal. The project will create 3,500 linear feet (2.57 acres) of canal, assuming the proposed rerouted canal exhibits an ordinary high water mark width of 32 feet as currently exists in section 2B Part 2 of the NWOD. Mitigation measures proposed for impacts to canals/ditches also include restoring surface water flow to adjacent wetlands to preconstruction conditions. As stated earlier, the canal/ditch classification is considered an open water jurisdictional nonwetland water of the United States. The project will result in a net increase in this type of jurisdictional nonwetland water of the United States. Temporary Wetland Impact Mitigation The temporary impacts to 5.37 acres of saline wet meadow wetlands and 0.12 acre of canal/ditch will be mitigated through restoration of these areas. The 5.37 acres of saline wet meadow wetlands will be restored to preconstruction condition following removal of the stockpiled soil and/or construction equipment. Any topsoil lost through the removal of stockpiled soil or temporary construction access will be replaced with wetland topsoil stockpiled from construction of the rerouted canal and access roads. The area will be seeded with the seed mix in Table 1. BIO-WEST, Inc. Northwest Oil Drain March 2014 8 Mitigation and Restoration Plan Table 1. Proposed Saline Wet Meadow Seed Mix. SPECIES NAME BROADCAST SEED Number of Seeds Per Pound Pounds of Pure Live Seed Per Acre Percent of Mix Botanical Name Common Name Distichlis spicata inland saltgrass 520,000 11.4 75.07% Juncus arcticus Arctic rush 10,900,000 0.1 13.80% Sporobolus airoides alkali sacaton 1,758,000 0.5 11.13% TOTAL 12 100.00% The seed mix will be broadcast over and raked into the soil, and straw mulch blanket will be staked over the top of the seedbed. Seeding will occur in fall and, to the greatest extent possible, winter and spring water levels within the wetland will be maintained to saturate the soil to the surface, providing optimal conditions for wetland seed germination. The 0.12 acre of canal/ditch area will be restored to preconstruction conditions following removal of the stockpiled soil. Minor additional temporary wetland impacts may be required during the construction. If these impacts are required, the impacted areas will be mapped, restored, and monitored in the same fashion as the planned temporary wetland impact areas. Upland Restoration In addition to wetland restoration, the backfilled 2,565 linear feet (1.86 acres) of Segment 2B Part 2 of the NWOD will be seeded with the upland seed mix shown in Table 2. The seed mix will be broadcast over the soil in the fall and raked into the soil. A straw mulch blanket will then be staked over the top of the seedbed. Table 2. Proposed Upland Seed Mix. SPECIES NAME BROADCAST SEED Number of Seeds Per Pound Pounds of Pure Live Seed Per Acre Percent of Mix Botanical Name Common Name Pascopyrum smithii western wheatgrass 110,000 4.3 19.91% Elymus trachycaulus slender wheatgrass 159,000 3 20.07% Sporobolus cryptandrus sand dropseed 5,298,000 0.1 22.30% Helianthus annuus annual sunflower 58,500 7.2 17.73% Thinopyrum intermedium intermediate wheatgrass 88,000 5.4 20.00% TOTAL 20 100.00% BIO-WEST, Inc. Northwest Oil Drain March 2014 9 Mitigation and Restoration Plan Monitoring Monitoring of the temporary impact restoration areas should occur until the areas are fully restored to the preconstruction conditions. Monitoring is proposed for a minimum of three growing seasons after restoration. Areas deemed unsuccessful after 3 years of monitoring will require the implementation of contingency measures. Photographs and notes of the restoration area conditions should be taken during monitoring. Wetlands located adjacent to the rerouted NWOD canal will be monitored for potential indirect impacts for a minimum of three growing seasons. Monitoring criteria for temporary wetland impact areas and wetland areas adjacent to the reroute that could be susceptible to indirect impacts will include monitoring the wetland vegetation and wetland hydrology. Representative sample points will be established and vegetation species and percent cover will be recorded at those sample points. Areas exhibiting less than 70 percent native facultative vegetation cover after 3 years of monitoring will be considered unsuccessful. Areas that do not exhibit indicators of wetland hydrology after 3 years of monitoring will also be considered unsuccessful. The unsuccessful areas will be mapped during annual monitoring. Contingency measures to correct unsuccessful areas include but are not limited to planting additional native wetland plant species, spraying undesirable weeds, and increasing available surface water to the areas. Contingency measures will be implemented as soon as it appears areas are not meeting and will not likely meet success criteria before the end of the 3-year monitoring period. If native wetland vegetation and/or wetland hydrology cannot be established in these areas within the 3-year monitoring period, then the areas will be considered unsuccessful and additional appropriate mitigation credits will be purchased from an approved mitigation bank at that time. An annual monitoring summary report will be prepared following each of the three monitoring seasons. The annual report will include the data gathered during the monitoring site visits. Any areas requiring contingency or remediation measures will be described and illustrated on a figure within the report. The contingency and/or remediation measures will also be described in detail within the report. Immediately upon completion of all construction activities and restoration of temporary impact areas, a post-construction map will be developed to confirm project area conditions. The map data will be collected in the field with a submeter-accurate GPS unit. The map will be included in a post-construction report that will be submitted to the EPA immediately following completion of all construction activities and restoration of temporary impact areas. Weed Treatment The temporary impact restoration areas will be treated annually for weedy species until such time as the native wetland species become established and dominant. The applied herbicide will be a brand approved for use in aquatic environments. Herbicide treatment efforts will be conducted under the appropriate Chevron safety protocol. A summary of the annual weed spraying effort will be included in the annual monitoring summary report. BIO-WEST, Inc. Northwest Oil Drain March 2014 10 Mitigation and Restoration Plan REFERENCES [DOF] Dalton, Olmsted, & Fuglevand, Inc., and EarthFax Engineering, Inc. 2013. Northwest Oil Drain Canal Segment 2B Remedial Approach. Northwest Oil Drain Canal Working Group, Salt Lake City, Utah. Midvale, Utah. [EMR] Environmental Resources Management. 2007. Final Report – Sediment Removal Action Northwest Oil Drain Project, Segments 1, 2 and 3. Salt Lake City Corporation, BP Products North America, Inc., Chevron USA, Inc. Salt Lake City, Utah. Environmental Laboratory. 1987. U.S. Army Corps of Engineers Wetlands Delineation Manual. Vicksburg (MS): U.S. Army Waterways Experiment Station. Technical Report Y-87-1. Lichvar, R.W., and J.T. Kartesz. 2009. U.S. Army Corps of Engineers North American Digital Flora: National Wetlands Plant List, Version 2.4.0 (https://wetland_plants.usace.army.mil). [Research and Development] U.S. Army Corps of Engineers Research and Development Center. 2008. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region. Hanover (NH): U.S. Army Corps of Engineers Research and Development Center. 93 p. plus appendices. [USFWS] U.S. Fish and Wildlife Service. 1988. National List of Plant Species that Occur in Wetlands: 1988 National Summary. Washington (D.C.): U.S. Fish and Wildlife Service, Ecology Section, National Wetlands Inventory. 244 p. APPENDIX A: NORTHWEST OIL DRAIN CANAL SEGMENT 2B PART 2 REROUTE TYPICAL CROSS SECTION APPENDIX B: MACHINE LAKE WETLAND MITIGATION BANK INFORMATION The information below was assemble by BIO-WEST from the website of the U.S. Army Corps of Engineers, Regulatory In-Lieu Fee and Bank Information Tracking System. https://rsgisias.crrel.usace.army.mil/ribits/f?p=107:10:3882008892619518::NO::P10_BANK_ID :418 Co General Information Machine Lake District: Sacramento FWS Field Office: Utah State: Utah Permit No: NA Total Acres: 1,077.00 Status: Approved Type: Private Commercial Website: http://www.machinelakebank.com /index.html Comments: Machine Lake consist of approximately 1,077 acres located west of Brigham City and north of the Bear River National Bird Refuge in Box Elder County, Utah. The bank will facilitate the rehabilitation of the rich wetland complex that has historically existed on the property. ntact Information Bank Sponsor R & P Wetlands & Waterfowl, LLC Midvale, UT Bank POC Mr Adam Adams - Consultant UT Email: aadams1@sablefinancial.com Phone: (866)743-9980 Google Map for Machine Lake Last Transaction: Jan 23, 2013 The credit totals shown on the ledger do NOT reflect any credit Credit Ledger Summary reservations or pending transactions. It is the responsibility of potential purchasers to contact the Sponsor and obtain written confirmation of credit availability. Name Available Credits Withdrawn Credits Released Credits Potential Credits Wetland Saline Wet Meadow 15.466 14.534 30 96.1 Freshwater Marsh Complex 2.06 .44 2.5 79.7 Mudflat Playa/Shallow Water 9.28 52.03 61.31 85 Freshwater Wet Meadow 0 0 0 118.2 Credit Classification Details Saline Wet Meadow Saline Wet Meadow is seasonally or perennially wet and contains species such as grasses, sedges, and rushes. It occurs in a saline environment such as around the Great Salt Lake and areas in Nevada. Predominant vegetation is salt grass (Distichlis spp.). Mostly found in association with playa habitats. Related HGM Type:Not SpecifiedShow HGM Description Cowardin Classification:Palustrine, N/A, Emergent