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HomeMy WebLinkAbout1.07 Stream crossing & wetland protection planStream Crossing & Wetland Protection Plan 1. Introduction 1.1 Purpose of Plan 1.2 Responsibilities 1.2.1 Company 1.2.2 Contractor 1.3 Definitions 1.4 Related Plans and drawings 2. Construction Methods 2.1 Dry Stream 2.2 Marking and Flagging 2.3 Hazardous Materials 2.4 Clearing and Grading 2.5 Vehicle and Equipment Crossing 2.5.1 Waterbodies 2.5.2 Wetlands 2.6 Waterbody Installation Methods 2.6.1 General Requirements 2.6.2 Dry Trench Construction 2.6.2.1 Dry Trench: Flume 2.6.2.2 Dry Trench: Dam & Pump 2.6.3 Open Cut Construction: Minor & Intermediate Waterbodies 2.7 Wetland Crossing Methods 2.7.1 Dry Conditions 2.7.2 Standing Water or Saturated Soil Conditions 3. Erosion Control & Restoration 3.1 Erosion Control 3.2 Restoration 4. References I. INTRODUCTION This Stream Crossing and Wetland Protection Plan (plan) describes measures to be taken by the ETC Canyon Pipeline, LLC (Company) and its contractors (Contractor) for construction activities in and around streams, rivers, and wetlands. No rivers, wetlands, or perennial streams will be crossed on federal surface managed by BLM. 1.1 PURPOSE OF PLAN This plan covers, and is designed to mlmmlze the environmental impacts to all jurisdictional wetlands, flowing streams, river crossings (waterbodies), and dry stream crossings. 1.2 RESPONSIBILITIES 1.2.1 Company The Company will be responsible for meeting the goals and objectives of this plan and for ensuring that the Contractor uses the metllOds described in this plan. The Company will also ensure that environmental oversight of the project includes preconstruction marking/flagging of all flowing streams, rivers, and wetlands as described in Section 2.2. The Environmental Inspector will ensure that the Contractor constructs through sensitive resources as required in this plan and will also ensure that all marking/flagging remains in place and is visible throughout construction. The Company will, prior to any ROW clearing and grading, ensure that the Contractor has sufficient environmental protection supplies and materials on hand to initiate installation of erosion control devices. The Company will ensure that the environmental protection supplies meet the specifications contained in this plan and other related plans as listed in Section 1.4. This includes straw bales, silt fence, erosion control matting, hazardous substances spill clean up equipment, and other materials. 1.2.2 Contractor The Contractor will be responsible for implementing the methods prescribed in this plan to meet site-specific conditions. The Contractor will ensure that all methods employed are installed and maintained correctly. It is the Contractor's responsibility to monitor the effectiveness of the installed devices and to correct any conditions that do not meet the requirements of this plan. The Contractor will be responsible for ordering and maintaining an inventory of environmental control supplies and materials to meet daily construction requirements as well as meeting emergency conditions. 1.3 DEFINITIONS Waterbody: Includes any natural or artificial stream, river, or drainage with perceptible flow at the time of crossing, and other permanent waterbodies such as ponds (both natural and stock ponds) and lakes. Minor Waterbody: Includes all waterbodies less than or equal to 10 feet wide at the water's edge at the time of construction. Intermediate Waterbody: Includes all waterbodies greater than 10 feet wide but less then or equal to 100 feet wide at the water's edge at the time of construction. Major Waterbody: Major waterbodies are defined as flowing streams and rivers that are greater than 100 feet wide at the water's edge at the time of construction. Wetland: Includes any area that satisfies the requirements of the current federal methodology for identifying and delineating wetland. 1.4 RELATED PLANS AND DRAWINGS The following documents include additional requirements specifically relating to construction at waterbodies and wetlands and are referenced throughout this plan. • Hazardous Materials Management and Spill Prevention and Countermeasure Plan • Reclamation Plan 2. CONSTRUCTION METHODS Specific construction methods will be determined by the Contractor utilizing the requirements of this plan as the minimum acceptable standards. 2.1 DRY STREAMS The following requirements for crossing flowing streams and wetlands do not apply to dry streams and drainages. Dry stream and drainage crossings wiIl be constructed using the same construction methods that will be used along the rest of the ROW, except that spoil wiIl be placed outside the channel to provide unrestricted drainage across the ROW. The Company Environmental Inspector will assist the Contractor, where necessary, in determining the limits of the dry channel. In wide channels, gaps may be left in the spoil piles to allow for the required drainage. During cleanup and reclamation, the preconstruction profiles and contours (including meanders of the streambed) of dry and intermittent streams will be re-established. 2.2 MARKING ANND FLAGGING The Company wiIl sign and/or flag the following boundaries at least 72 hours prior to any clearing or grading, or before any construction crew is within I mile of any site requiring signs and/or flagging. + 60-foot limits of the ROW in waterbodies and wetlands (survey flagging) + Edges of wetland boundaries ("Wetland Boundary" sign) + Limits of lOa-foot buffers for fueling and concrete coating activities ("No Refueling" sign) + IO-foot buffers from the water's edge for spoil storage ("No Spoil Storage Beyond This Point" sign) No activities are permitted outside of approved work areas. 2.3 HAZARDOUS MATERIALS The Contractor will comply with the requirements included in the project's and the Contractor's Hazardous Materials Management and Spill Prevention and Countermeasure Plans. Contractor will not store hazardous materials, chemicals, fuels, lubricating oils, or perform concrete coating activities within 100 feet of any water body or dry drainage, or within any designated municipal watershed area (except at locations designated for these purposes by the BLM and/or Environmental Inspector). Equipment or vehicles that are crossing or working within 100 feet of waterbodies will not be refueled unless a specific exception is given by an Environmental Inspector. If any hazardous materials must be temporarily stored or transferred within 100 feet of a stream (i.e. stationary pumps), then it must be placed within a secondary containment structure as specified in the Hazardous Materials Management and Spill Prevention and Countermeasure Plan. 2.4 CLEARING AND GRADING Clearing and grading at waterbod y crossings will be limited to that needed to construct the crossing. During clearing, the root systems will be left in place except over the trench line and in areas that require grading. Root systems may also be removed along the travel lane as determined necessary by the Environmental Inspector to allow safe passage by rubber tired vehicles. Removal of root systems over the travel lane to allow safe vehicle access in areas that do not require grading will require a variance on federal lands. Grading will be limited to the trench line, the banks of streams, and locations with side slopes. Grading within 50 feet of stream banks is restricted to that needed for the equipment crossing, until construction of the actual pipeline crossing has begun. Prior to or immediately after any ground disturbing activity, temporary sediment control devices such as silt fence and straw bales will be installed at the base of all slopes leading to waterbodies in accordance with the project's Soil Conservation, Sedimentation, and Erosion Control Plan. The Contractor will maintain these devices in functioning order until construction activities, including reclamation activities, have been completed. 2.5 VEHICLE AND EQUIPMENT CROSSING 2.5.1 Waterbodies Only clearing equipment may cross waterbodies prior to the installation of an equipment bridge. Waterbody fording by clearing equipment is limited to one crossing per piece of equipment. Fording will not be used as a crossing method for other vehicles or equipment. Equipment bridges will be one of the following types: • Portable bridges that span the channel • Flume(s) and clean rock riprap (with a 20-inch minimum diameter) • Timber equipment mates (installed above the waterline) used as a bridge over small waterbodies Each bridge will be designed to allow for the maximum predicted flows for the time frames that it will be in place, including all expected precipitation events. The Contractor will also maintain bridges so that soil from equipment or the bridge abutment is prevented from entering any waterbody. All equipment bridges will be removed as soon as possible after permanent seeding. 2.5.2 Wetlands If the wetland is dry, equipment can use the ROW for access on an as-needed basis with as much traffic as possible routed around the wetland. Fro wetlands with standing water or saturated soils, the equipment operating in the wetland will be limited to that needed to construct the wetland crossing. The ROW will not be used as an access route unless it is the only possible method of access. Foreign material (upland soil, rock, tree stumps, etc.) will not be imported into the wetland to stabilize the working area. If standing water or saturated soils are present, equipment will work from, and access across, timber equipment mats. 2.6 WATERBODY INSTALLATION METHODS There are three general construction methods for installing pipelines across waterbodies: 1) Dry Trench Method: routing the flow around the trench during trench excavation, installation of the pipeline and backfilling. 2) Open-Cut Method: allowing the stream flow to continue though the work area during trench excavation, installation of the pipeline, and backfilling. 3) Directional Bore Method: allowing the pipeline to be pulled into a subsurface bore hole which results in no surface disturbance. Contractor will use the directional bore method on all major crossings unless otherwise dictated by BLM. 2.6.1 General Requirements The following requirements apply to all waterbody-crossing methods. + Bore pits will be kept to a minimum size + Spoil storage from pit excavations will be at least 100 feet from the water's edge and will be located behind sediment baniers. + Drilling fluids will be dept contained at all times 2.6.2 Open Cut Construction: Minor and Intermediate Waterbodies The open cut method applies to minor and all intermediate waterbody crossings. Grading and trenching of the ROW adjacent to (upslope of) the stream banks, and fabrication and weighting of the pipe section for the crossing will be completed prior to in-stream trenching. Topsoil will be salvaged from the stream banks prior to grading and trenching. If topographic conditions allow, a hard plug will be left in place slightly above the stream level. Trenching will than begin from the approximate steam center toward the remaining bank material or hard plugs on either (or both) side(s) with all spoil piles stored a minimum of 10 feet from the water's edge and behind sediment barriers or other containment structures. After the pipe has been installed, trench soft plugs will be placed as close to the water's edge as possible to prevent upland backfill material and ground water from entering the waterbody. The upland sections of the trench will than be dewatered into an upland area so that the tie-in and backfilling procedures can be completed in a fairly dry condition. The in-stream trench will than be backfilled with previously excavated material and the channel bottom and banks restored. 2.7 WETLAND CROSSING METHODS 2.7.1 Dry Conditions Prior to trenching all topsoil up to 12 inches in depth, as determined by the Environmental Inspector, will be stripped from over the trenchline. If the wetland is located on a sidehill, topsoil will be stripped from the entire area being graded. Topsoil will be stockpiled in a location where it will not be mixed with any upland soils or wetland subsoil. Care will be taken to ensure that the area stripped over the trenchline is wide enough to include topsoil over trench sidewalls that may slough off due to high ground water. Sediment barriers will be installed between the spoil piles and the edge of the ROW, where the Environmental Inspector determines that there is a potential for material to leave the ROW. If dewatering is required, the requirements described in Appendix "B", Section 3.2.4, will be followed. 2.7.2 Standing Water or Saturated Soil Conditions If possible, as determined by the Environmental Inspector, all topsoil up to 12 inches in depth will be removed and stockpiled as directed above in Section 2.7.1. Timber equipment mats, if needed, will be the method of stabilizing the work area. Sedimentation barriers will be placed on the down-slope edge of the ROW if the wetland continues beyond the ROW or both edges of the ROW is flat and there is a potential for material to leave the ROW. The drag section needed for each wetland crossing will be built in an upland area. If the wetland working space is stable, as deteImined by the Company Construction and Environmental Inspector, or is short (less then 200 feet), normal construction techniques utilizing equipment mats will be used for construction. For unstable conditions in larger saturated wetlands a float technique will be used to lay the pipe. Tie-in locations will be in upland areas, if possible, with a soft trench plug between the tie-in location and the wetland. Tie-in locations that require dewatering will use a dewatering structure that is located outside the wetland boundary, so that no heavily silt-laden waters reach any waterbodies or wetlands. If trench dewatering is required, implement measures described in Appendix "B", Section 3.2.4. 3. EROSION CONTROL AND RESTORATION 3.1 EROSION CONTROL Immediately after initial ground disturbance, temporary erosion control measures will be installed. This will include at a minimum, sediment barriers at the base of all slopes along the ROW leading to waterbodies and wetlands. All temporary controls will be maintained until permanent erosion control is in place as defined in the Soil Conservation, Sedimentation, and Erosion Control Plan. After pipe installation, trench breakers will also be placed at the base of slopes leading to waterbodies and where groundwater may migrate along the trench. Waterbars will be placed just below the trench breakers to carry off any excess water into vegetated areas. Streambanks and other steep slopes around waterbodies may require additional stabilization beyond the replacement of original contours and other nOImal erosion control requirements (as described in the Soil Conservation, Sedimentation, and Erosion Control Plan). Stabilization of streambanks with on-site materials (e.g. placing felled trees along the streambanks) will be deteImined on site by the BLM's field representative and with appropriate peImit approvals. Erosion control matting may be required for stabilization above the high water mark for streambanks over 50 percent sloped and as directed by the Company. The matting will extend up the banks 100 feet or until the slope is less than 50 percent, whichever is less. Installation and stapling of erosion control matting will follow procedures specified in the details. For streambank installations, mats will be laid parallel (upper mat overlapping lower mat in a shingle pattern) to the waterbody to a point above the top of the bank. As mentioned above, native materials (rocks, logs, etc.) may be used in conjunction with the matting to aid in stabilization of banks. Below the high water mark, clean riprap may be used on stream banks, as directed by the Company, to prevent bank erosion. Contractor may use excess rock obtained from the ROW for rip-rap, if rock is of sufficient quality and quantity as deteImined by the Company, or will obtain rock from an approved commercial source. 3.2 RESTORATION Original meanders, profiles, cross-sections, and other contours of water bodies and 25 feet up each stream bank will be restored, final cleanup concluded, seeding accomplished, and mulching or erosion control mats installed, prior to the end of the following time frames, unless otherwise authorized by the Company (private lands) and/or the BLM agency representative (federal lands). • Minor streams -24 hours after initial in-stream disturbance • Intermediate streams -72 hours after initial in-stream disturbance • Wetlands -10 days after backfilling There are exceptions to these time frames. • Temporary bridges or other materials (e.g. timber mats) required for access will not have to be removed until they are no longer needed. All other areas at the crossing, not needed for the bridge abutments, must meet the requirements above. • Very steep or incised stream/river banks with the likelihood of further erosion will not have the original contour restored. These stream/river banks will be restored at a 1.5 to 1 slope (horizontal to vertical), which is equivalent to 67 percent slope. Transition from adjacent slopes, to those reclaimed over the ROW will be made so as to prevent erosion between these transitions, and to minimize eddying at the tie of these slopes. If reclamation and seeding is deferred more than 10 days after final grade restoration near waterbodies and wetlands, all disturbed slopes above waterbodies and wetlands will be temporarily stabilized by applying straw mulch for a minimum distance of 100 feet above the edge ofthe waterbody or wetland. Fertilizers, herbicides, and lime will not be used within 100 feet of water bodies.