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HomeMy WebLinkAbout6.n. Northern Natural Gas Request for a Conditional Use Permit for a Transmission Facility Greater than ¼ Mile in Length EXECUTIVE SUMMARY City Council Regular Meeting: May 16, 2016 AGENDA ITEM: Case 16-09-CUP Northern Natural Gas Request for a Conditional Use Permit for a Transmission Facility Greater than ¼ Mile in Length AGENDA SECTION: Consent PREPARED BY: Kyle Klatt, Senior Planner AGENDA NO. 6.n. ATTACHMENTS: Resolution, Except of Draft 4/26/16 Minutes, CUP Application Summary; Extended Work Hours Request; Project Description; NNG Email Update (Trees); Horizontal Directional Drilling Information; Fire Marshall Review Comments; Easement Location Map; Pipeline Plan; Public Property Map; Tree Impact Map; Excerpt Planning Commission Minutes April 26, 2016 APPROVED BY: ddj RECOMMENDED ACTION: Motion to approve a resolution granting a conditional use permit for Northern Natural Gas to construct a natural gas transmission line greater than ¼ mile in length, subject to conditions. SUMMARY The City Council is being asked to consider a Conditional Use Permit (CUP) request from Northern Natural Gas Company (NNG) for a new transmission facility greater than ¼ mile in length. NNG is seeking approval to install a new 20 inch natural gas pipeline parallel to an existing smaller pipeline in the north-central portion of Rosemount. Construction of the pipeline will begin in March of 2017 and be completed by October 2017. PLANNING COMMISSION ACTION The Planning Commission held a public hearing to review the conditional use permit request on April 26, 2016. Commissioners asked several questions about the planned directional drilling method and potential impacts to neighboring home owners from the project. Bryan Kruger of NNG noted that directional drilling will take place at depths in excess of 20 feet and that there should be no tremors or other surface impacts over the pipeline. He indicated that noise will be focused around the entrance and exit points of the pipeline where drilling occurs, and that they will add sound mitigation around each site if any work exceeds the maximum sound level of 55dB. In cases where sounds around this level cannot be mitigated, NND will pay to temporarily relocate adjacent residents during construction activity. Staff noted that 55dB is generally considered the ambient noise level as supported by recent sound studies reviewed by the City. The Commission expressed an interest in the amount of time that each segment will take to complete, especially in light of the applicant’s request for extended working hours. Mr. Kruger noted that most directional drilling runs should be completed within a 24-48 hour time period. He indicated that because the pipeline will be constructed in a rural area, there will be a few homes impacted around each drilling site, and that there will be a fair amount of separation from most homes. In response to a Commission question, Mr. Kruger noted that the proposed pipeline will be located 25 feet from the 2 existing line unless this amount of separation cannot be achieved due to the width of the existing easement. The Commission received testimony from one neighboring property owner who asked for clarification on where the line would run across his property. The Commission suggested that the homeowner meet with City Staff and the applicant to review more detailed pipeline plans. Staff explained that the City will not be involved in any new easement acquisition, and that the applicant will need to secure any new or temporary easements before starting the project. NNG, like local governments, can use eminent domain to secure necessary right-of-way for its pipeline. The Planning Commission voted unanimously to recommend approval of the conditional use permit with the conditions as drafted by Staff. BACKGROUND The proposed NNG work within Rosemount is part of a larger project to construct a 7.8 mile long, 20 inch diameter pipeline in Dakota County between NNG’s existing Rosemount Junction located near the intersection of Bacardi Avenue and Bonaire Path and its Cedar Station Yard in Eagan. The majority of the proposed pipeline will be installed next to an existing 16 inch pipeline except for a 2.3 mile segment located along State Highway 77 in Eagan. All but a small portion of the pipeline within Rosemount will be located within existing utility easements. The project is needed to support the growing demand for natural gas in the area, and will provide a loop for NNG’s existing branch line that ultimately feeds Xcel Energy’s Cedar power plant. The section of the pipeline proposed within Rosemount will start at the Rosemount Junction yard as noted above and follow an existing easement in a northwesterly trajectory across the Progressive Rail line, 130th Street West, South Robert Trail, McAndrews Road/Dodd Boulevard intersection, and finally across 120th Street and into the City of Eagan through Lebanon Hills Park. The attached map labeled Exhibit “A” highlights the path of the proposed pipeline and also shows the existing and proposed easements that will support construction of the line. Of particular note are the areas shaded in blue representing temporary easements, needed primarily for staging of construction activity, and the green-shaded areas depicting new easements. New easement acquisition is limited to small runs of pipe between McAndrews Road and 120th Street. Unlike other recent pipeline projects in Rosemount, the majority of the proposed pipeline will be installed using a horizontal directional drilling process (versus open trenching) that should reduce the overall impact of the construction project on the landscape. In general, directional drilling uses a specialized machine to bore a hole underground and then a pipe is pulled back through this hole to occupy the space (as opposed to digging a trench, laying the pipe, and covering the trench). The advantage of this construction method is that land disturbance and activity is typically limited to the entry and exit points for the pipeline. The map labeled Exhibit “B” attached to this memorandum identifies those portions of the pipeline that will be built using traditional open trenching methods and those that will be installed using a directional drilling process. For the most part, open trenching will occur in areas of open fields, while directional drilling will be used in areas of wetlands, heavy tree cover, or areas with larger numbers of buildings and private improvements. NNG has provided the City with a separate attachment describing the directional drilling process. In addition to identifying the type of pipeline construction, Map “B” also delineates the drill locations for the pipe. These locations signify where the staging will occur for the equipment necessary to perform the drilling work, and therefore areas where some impacts are expected for surrounding property owners. In order to support these activities, NNG has identified temporary easement areas 3 needed for access and drilling equipment placement. These easements are being negotiated between the applicant and property owners; no direct staging activity is anticipated on public property or within any public rights-of-way. Access to the drilling and trenching sites will occur from public roads, either through private drives or via existing field access points. As part of its application, NNG is requesting an exception to the City’s standards regulating construction activity operating hours. The applicant is concerned that the directional drilling process will take a long time to complete for the longer runs being proposed and has noted that interrupting the drilling process before reaching the end point is not feasible because the pipe can become stuck if work is halted partway through the run. Staff has found that the request for flexibility from normal working hours is justified in this case because it should help shorten the overall duration of the project in Rosemount. The directional drilling also ensures that the minimal amount of time possible is spent working in each staging area. Finally, from an impact perspective directional drilling is preferred over open trenching. The applicant has proposed mitigation measures to help off-set impacts to adjacent properties when the drilling is taking place, and staff is suggesting that these proposed measures be included as a condition of approval. Staff is therefore recommending approval of the request for extended working hours. During the review of previous pipeline projects, the City Attorney has advised that the City’s authority is limited to crossing of city right-of-way and public property, and the City has no authority over routing of the pipeline on private property. Federal regulations cover pipeline routing on private property and preempt local authority. For this request, the City’s authority is therefore limited to the public road crossings at 130th Street West, Blanca Avenue, Bolivia Avenue, South Robert Trail (MnDOT responsibility), McAndrews Road, Dodd Boulevard, and 120th Street West, and the operational standards of construction such as hours of operations, dust control, noise, etc. Because there is an extensive environmental and federal regulatory review associated with the pipeline, NNG is seeking its local permits well in advance of construction. The advanced review is beneficial for the City because it provides ample time to address any anticipated impacts, but does create a problem because the Zoning Ordinance requires all conditional uses to be established within one year of approval. Given the unusual factors associated with a new pipeline project, staff is recommending that the CUP remain valid through the project completion date of October 2017. ANALYSIS/REVIEW Focusing on those areas that the City can review and regulate as it pertains to a public utility pipeline, the main issues that are expected to arise from the project can be summarized as follows: Direct impacts from the construction operations, including noise and dust from drilling equipment, trucks, and other machinery used to install the pipeline. In addition to the CUP request, the applicant will need to secure a utility permit from the City for all work within and under public property. This permit will address some of these issues, especially as they relate to noise and construction appearance. The applicant will be expected to follow general city regulations concerning nuisances both during and after construction of the pipeline. The Fire Marshal has also provided general review comments and has asked for certain information or actions to help address public safety concerns with the project. Loss of vegetation and trees along the planned route. The applicant was asked to prepare a separate map detailing any trees that would be impacted by the project. This map indicates that there are 118 trees within the proposed alignment, and that of these trees, approximately 20 will need to be removed. The number of trees expected to be removed is fairly small 4 because no tree removal is anticipated in areas where the pipe is installed via the directional drilling process. Some tree removal will be necessary to get access to the drilling sites and to be able to properly set up the needed equipment. Most of the tree removal will occur in the staging area between South Robert Trail and Dodd Boulevard south of McAndrews Road. Staff is recommending a condition of approval that requires the applicant to post a letter of credit to guarantee the replacement of any infrastructure or landscaping removed from public property. City right-of-way crossings and work under City streets. Because the project is occurring within an existing easement, the City does not have the ability to suggest alternative crossing locations for the pipeline. The City Engineer has reviewed the proposed project alignment, and does not anticipate any specific construction issues that cannot be managed through the utility permit review. A larger staging area and several drilling points are planned around the McAndrews Road and Dodd Boulevard intersection. Access and private property impacts. Because nearly 75% of the pipeline through Rosemount will be installed using directional drilling methods, the direct impacts to adjacent properties are much less than if the pipe was installed via an open trenching method. This means that direct property impacts will be focused around individual staging areas rather than over long lineal runs across private property. The applicant has committed to maintaining a sound limit of 55dBA at the nearest residence or temporarily relocating these residences when this standard cannot be achieved. The construction access points will need to be approved by the City Engineer as part of the utility permit. Essential Services Permit Zoning Ordinance Section 11-2-17D. states that an Essential Services Permit for transmission facilities over ¼ mile in length must include five findings: 1. The proposed siting complies with the city's comprehensive guide plan. Finding: The proposed natural gas line is to provide expanded capacity to meet increasing demands for natural gas and to provide a loop for an existing branch line. The pipeline will be located within an existing easement, and will cross properties that are guided for transitional or rural residential land uses. The current zoning for the affected properties are either RR – Rural Residential or AG – Agricultural, both of which allow for the proposed transmission line as a CUP. 2. To the extent possible, the proposed siting is within or adjacent to existing public rights of way, private utility easements or other designated corridors for transportation or transmission facilities. Finding: For this request, the City’s authority is limited to the public road crossings described above and the operational standards of construction such as hours of operations, dust control, noise, etc. The applicant is proposing to directional drill under all roadways, and will be securing temporary easements adjacent to public roads to provide adequate room for staging of equipment, vehicles, and workers. The City’s ability to restrict crossings is limited because the pipeline will be located within an existing easement. The City Engineer noted that any expected issues over or adjacent to public roadways may be addressed though the utility permitting process. 3. The proposed siting is necessary based upon a need and locational analysis. Finding: In addition to a general increase in demand for natural gas services, the applicant has noted that the pipeline is needed to fulfill a contractual obligation with Xcel Energy to provide 5 a minimum amount of pressure at the Cedar Station facility. This facility supplies natural gas for Xcel’s Black Dog power plant. Staff finds that the proposed alignment has completed the need and locational analysis. 4. Impacts, including, but not limited to, noise and views, are identified and mitigated. Finding: The City Utility Permit and the existing City Code regulations will address any issues or impacts including noise and construction appearance. Staff is also recommending a condition requiring NNG to limit construction noise impacting near-by residences or to temporarily relocate these residents when the specified sound levels cannot be met. 5. The proposed siting will not create hazards to the health, safety and general welfare of surrounding property owners or natural environment. Finding: Staff finds that NNG has considered the natural environment in their alignment and is proposing construction alternatives that will have less impact on the general welfare of the surrounding property owners. RECOMMENDATION The Planning Commission and Staff recommend approval of the Conditional Use Permit subject to the conditions provided. This recommendation is based on the plans submitted by the applicant and the findings made in this report. CITY OF ROSEMOUNT DAKOTA COUNTY, MINNESOTA RESOLUTION 2016- A RESOLUTION APPROVING A CONDITIONAL USE PERMIT (CUP) TO CONSTRUCT A NATURAL GAS TRANSMISSION LINE OVER ¼ MILE IN LENGTH WHEREAS, the City of Rosemount received an application for a Conditional Use Permit (CUP) from Northern Natural Gas (NNG) to construct a 20” natural gas transmission line; and WHEREAS, on April 26, 2016, the Planning Commission of the City of Rosemount held a public hearing to review the CUP application from Northern Natural Gas construct a 20” natural gas transmission line; and WHEREAS, the Planning Commission adopted a motion recommending that the City Council approve the CUP for Northern Natural Gas subject to the conditions listed below; and WHEREAS, on April 26, 2016, the City Council of the City of Rosemount reviewed the Planning Commission’s recommendation and the CUP application to construct a 20” natural gas transmission line. NOW, THEREFORE, BE IT RESOLVED, the Council of the City of Rosemount hereby approves the CUP to construct a 20” natural gas transmission line beginning from the NNG Rosemount Junction town border station located at 132nd St W and Bacardi Ave W in Rosemount to Northern Natural Gas’s Cedar Station town border station in Eagan, subject to the following conditions: 1. Submittal and approval of a City Utility Permit from the City Engineer. 2. All construction and restoration activities shall conform to the City of Rosemount General Specifications and Standard Detail Plates for Street and Utility Construction. 3. Construction hours outside of those specified in City Code Section 9-7-2 are permitted provided the extended hours are necessary to complete horizontal directional drilling work for long runs that cannot be completed during the permitted construction time period. The applicant shall provide advance notice to the City when activities will extend beyond the working hours specified by the City Code. 4. Northern Natural Gas Company shall limit construction noises from horizontal directional drill activities to 55 dBA at any residential dwellings or will work with the resident(s) of said dwellings to temporarily relocate during construction activities. 5. Compliance with the Fire Marshal’s recommendations in a memorandum dated 4/20/16. 6. All infrastructure and landscaping removed from City property shall be restored and replaced upon completion of the pipeline project, including a one year warranty period. A letter of credit for 110% of the value of the infrastructure and landscaping shall be submitted to the City prior to work commencing. RESOLUTION 2016- 7. NNG shall submit an updated map book to the City similar to the maps provided with its Federal Energy Regulatory Commission filing showing the location of the existing and proposed pipeline prior to construction. 8. The Conditional Use Permit shall be valid through the projected completion date of October 31, 2017. ADOPTED this 17th day of May, 2016 by the City Council of the City of Rosemount. __________________________________________ William H. Droste, Mayor ATTEST: ___________________________________ Clarissa Hadler, City Clerk 2 Northern Natural Gas, in response to customer demand for energy for electrical generation for residential and commercial customers, is evaluating the construction of certain natural gas pipeline facilities. Although the final scope of the facilities will be determined after finalizing customer requirements and a full engineering analysis, the preliminary scope has been identified as a 7.8-mile 16-inch-diameter pipeline segment in Dakota County, Minnesota. As currently contemplated, the 7.8-mile 16-inch-diameter pipeline would be installed near the communities of Eagan and Rosemount, Minnesota. Approximately 5.5 miles of the line will loop an existing Northern Natural Gas pipeline. The end of the proposed pipeline route deviates from the existing pipeline route to follow an existing utility corridor. FOR SURVEY PERMISSION QUESTIONS, PLEASE CONTACT: Dale Ahlsten of ProSource Technologies, LLC •763-233-543 7 or dahlsten@prosourcetech.com EAGAN, MINNESOTA ROSEMOUNT, MINNESOTA NORTHERN NATURAL GAS PROJECT REGULATORY AUTHORITY Northern is regulated by the Federal Energy Regulatory Commission (FERC) under section 7(c) of the federal Natural Gas Act and plans to file an application with FERC requesting a Certificate of Public Convenience and Necessity authorizing the construction and operation of the project facilities. The approval process will start with a formal pre- filing review process. Northern expects to file an application for approval to begin the pre-filing process in September 2015. During the pre-filing process, Northern will hold public open houses along the proposed pipeline route. Potential affected landowners will receive formal notification from FERC and be sent information about the facilities and the approval process. After the pre-filing process is complete, Northern will file a case-specific application with FERC – tentatively scheduled for June 2016. During the formal review process, interested stakeholders, including landowners, will have additional opportunities to comment on the proposed facilities. WHAT NORTHERN IS DOING NOW In anticipation of the authorization and construction of these facilities, Northern is approaching landowners along the construction route seeking permission to conduct surveys. Northern’s third-party contractor, ProSource Technologies, will be contacting landowners to seek permission to enter their land to conduct the surveys. The environmental and civil surveys are needed to identify environmental resources within the construction area and to determine the area’s topography and the effects of these resources and topography on construction planning. WHAT NORTHERN IS NOT DOING Obtaining survey permission is the first step of a long multi-phased process for the construction of the facilities. Northern is not specifically seeking to purchase easements nor are construction plans finalized. In fact, the survey corridor will encompass lands that may not be used for construction. The information from the surveys will be used during FERC review of the project. The process of conducting surveys – for which Northern is seeking permission – is a critical component to ascertaining the best route to minimize environmental and landowner impacts and to identify the appropriate remediation measures that will be required. ENVIRONMENTAL RESPECT Northern Natural Gas is committed to respecting the environment before, during and after construction. The photographs to the right demonstrate the extent of Northern’s remediation efforts following the installation of below ground pipeline. SAFETY Natural gas pipelines are the safest and most reliable method of transporting energy. As an interstate natural gas pipeline, Northern is in full compliance with all federal pipeline safety regulations. COMMITMENT TO OUR NEIGHBORS Northern operates 14,700 miles of pipeline in 11 states; Northern has five field offices and 106 employees in Minnesota. Our employees live and work in the state. Northern is a good neighbor when dealing with landowners. RELIABILITY Northern’s customers, which includes the local distribution companies that serve your businesses and homes, rely on Northern for the reliable delivery of needed natural gas supplies. Northern rates #1 in customer satisfaction. FACILITY CONSTRUCTION TIMELINE SUMMER 2015 Obtain survey permission SEPTEMBER 2015 File with FERC for pre-filing authorization JUNE 2016 File with FERC for specific facility authorization MARCH 2017 Receive FERC authorization subject to construction and environmental remediation conditions SPRING – FALL 2017 Construction of facilities NOVEMBER 2017 Facilities placed into service PROJECT FACTS The pipeline project will provide additional needed natural gas – energy that will be used for the generation of electricity to meet increasing consumer demand. More than $46 million will be invested in Minnesota for the development and construction of these facilities. Project construction is governed by strict federal rules aimed at minimizing impacts to landowners and the environment. Like other projects constructed by Northern in the state, the Ventura North project will be constructed with the safest and most environmentally friendly processes. Northern already safely operates more than 3,300 miles of underground pipeline and 24 compressor units in the state of Minnesota. Pipelines are the safest and most reliable way to transport energy. From: Sent: To: Subject: TreeRosemountAmountsMap_032916.pdf Attachments: HiKyle, NNGwouldlikemetoconveytotheCityofRosemountthattheintentoftheHDDistoavoidsurfacedisturbanceand removaloftrees,whichisthereasonNNGisHDDingthemajorityoftheCity.TheHDDwillbeataconsiderabledepthat theselocationsandshouldnotimpacttherootsystems. ThefollowingisfromourGIStechnicianregardingtheattachment: ͻŷĻattachmentshowsthelocatedandextractedTREEDatafromtheAlignmentPlans.AlthoughthereǞğƭƓ͸Ʒ anyDataassociatedwiththeIndividualTrees,i.e.Size,Diameter,species,etc. ItgaveusanAPPROXIMATELocationoftheTrees.Thismayormaynotincludenewtrees,sincethesurveywas created. OntheMapProvided,thereisatreecountofimpactedtreesintheRosemountarea(118Trees) Basedoffofthedrill/trenchlocations,wecanassumethatthetreestoberemovedareacountof(20 Trees).Thiswasbasedoffoftrencheddatalocations. Although,therecanbesomerootdamagetotreesthataredrilled,thesecountsneedtobeexaminedonacase bycasesituationandbedeterminedinthefieldattimeofdrilling.PleaseTakealookattheattachedPDFand letmeknowifthereareanychangesƓĻĻķĻķ͵ͼ IamplanningondroppingoffahardcopyoftheCUPapplicationthisafternoonaround3:30pmatyourofficeandam wonderingifyouwouldbeavailabletomeetwhenwedropofftheapplicationthisafternoon?Thatwaywecanquickly gooverthemapshowingwheretreesarelocatedandseeifyouwouldlikethisdescribedinanyotherwayinthe application.NNGdoesneedtohaveitsubmittedbytoday,sowewanttomakesurethereźƭƓ͸Ʒanythingelseyouwould need. Thankyou, Robert Koehler | Acquisition / Relocation Specialist ProSource Technologies, LLC. | rkoehler@prosourcetech.com Office: 763.786.1445 Ext.119 | Direct: 763.233.5419 | Cell: 651.253.0003 | Fax: 763.786.1030 1 The Horizontal Directional Drilling Process The tools and techniques used in the horizontal directional drilling (HDD) process are an outgrowth of the oil well drilling industry. The components of a horizontal drilling rig used for pipeline construction are similar to those of an oil well drilling rig with the major exception being that a horizontal drilling rig is equipped with an inclined ramp as opposed to a vertical mast. HDD pilot hole operations are not unlike those involved in drilling a directional oil well. Drill pipe and downhole tools are generally interchangeable and drilling fluid is used throughout the operation to transport drilled spoil, reduce friction, stabilize the hole, etc. Because of these similarities, the process is generally referred to as drilling as opposed to boring. Installation of a pipeline by HDD is generally accomplished in three stages as illustrated in Figure 1. The first stage consists of directionally drilling a small diameter pilot hole along a designed directional path. The second stage involves enlarging this pilot hole to a diameter suitable for installation of the pipeline. The third stage consists of pulling the pipeline back into the enlarged hole. Pilot Hole Directional Drilling Pilot hole directional control is achieved by using a non-rotating drill string with an asymmetrical leading edge. The asymmetry of the leading edge creates a steering bias while the non-rotating aspect of the drill string allows the steering bias to be held in a specific position while drilling. If a change in direction is required, the drill string is rolled so that the direction of bias is the same as the desired change in direction. The direction of bias is referred to as the tool face. Straight progress may be achieved by drilling with a series of offsetting tool face positions. The drill string may also be continually rotated where directional control is not required. Leading edge asymmetry can be accomplished by several methods. Typically, the leading edge will have an angular offset created by a bent sub or bent motor housing. This is illustrated schematically in Figure 2. It is common in soft soils to achieve drilling progress by hydraulic cutting with a jet nozzle. In this case, the direction of flow from the nozzle can be offset from the central axis of the drill string thereby creating a steering bias. This may be accomplished by blocking selected nozzles on a standard roller cone bit or by custom fabricating a jet deflection bit. If hard spots are encountered, the drill string may be rotated to drill without directional control until the hard spot has been penetrated. DRILLING FLUID RETURNS ANNULUS DESIGNED DRILLED PATH DRILL PIPE EXIT POINTENTRY POINT HORIZONTAL DRILLING RIG PILOT HOLE PREREAMING DRILL PIPE TYPICAL DIRECTION OF PROGRESS DIRECTION OF PROGRESS DIRECTION OF PROGRESS PULLBACK DRILL PIPE DRILL PIPE PREFABRICATED PULL SECTION ANNULUS ANNULUS DRILLING FLUID RETURNS DRILLING FLUID RETURNS Figure 1 The HDD Process STEERING TOOL BIT MUD MOTORORIENTING SUB NON-MAGNETIC COLLAR BENT MOTOR HOUSING ANGULAROFFSET Figure 2 Bottom Hole Assembly Downhole Motors Downhole mechanical cutting action required for harder soils is provided by downhole hydraulic motors. Downhole hydraulic motors, commonly referred to as mud motors, convert hydraulic energy from drilling mud pumped from the surface to mechanical energy at the bit. This allows for bit rotation without drill string rotation. There are two basic types of mud motors; positive displacement and turbine. Positive displacement motors are typically used in HDD applications. Basically, a positive displacement mud motor consists of a spiral-shaped stator containing a sinusoidal shaped rotor. Mud flow through the stator imparts rotation to the rotor which is in turn connected through a linkage to the bit. In some cases, a larger diameter wash pipe may be rotated concentrically over the non-rotating steerable drill string. This serves to prevent sticking of the steerable string and allows its tool face to be freely oriented. It also maintains the pilot hole if it becomes necessary to withdraw the steerable string. Downhole Surveying The actual path of the pilot hole is monitored during drilling by taking periodic readings of the inclination and azimuth of the leading edge. Readings are taken with an instrument, commonly referred to as a probe, inserted in a drill collar as close as possible to the drill bit. Transmission of downhole probe survey readings to the surface is generally accomplished through a wire running inside the drill string. These readings, in conjunction with measurements of the distance drilled since the last survey, are used to calculate the horizontal and vertical coordinates along the pilot hole relative to the initial entry point on the surface. Azimuth readings are taken from the earth's magnetic field and are subject to interference from downhole tools, drill pipe, and magnetic fields created by adjacent structures. Therefore, the probe must be inserted in a non magnetic collar and positioned in the string so that it is adequately isolated from downhole tools and drill pipe. The combination of bit, mud motor (if used), subs, survey probe, and non magnetic collars is referred to as the Bottom Hole Assembly or BHA. A typical bottom hole assembly is shown as Figure 2. Surface Monitoring The pilot hole path may also be tracked using a surface monitoring system. Surface monitoring systems determine the location of the probe downhole by taking measurements from a grid or point on the surface. An example of this is the TruTracker System. This system uses a surface coil of known location to induce a magnetic field. The probe senses its location relative to this induced magnetic field and communicates this information to the surface. This is shown schematically in Figure 3. SURFACE COIL KNOWN CORNER LOCATIONS SURVEY PROBE Figure 3 TruTracker Surface Monitoring System Reaming & Pullback Enlarging the pilot hole is accomplished using either prereaming passes prior to pipe installation or simultaneously during pipe installation. Reaming tools typically consist of a circular array of cutters and drilling fluid jets and are often custom made by contractors for a particular hole size or type of soil. Prereaming Most contractors will opt to preream a pilot hole before attempting to install pipe. For a prereaming pass, reamers attached to the drill string at the exit point are rotated and drawn to the drilling rig thus enlarging the pilot hole. Drill pipe is added behind the reamers as they progress toward the drill rig. This insures that a string of pipe is always maintained in the drilled hole. It is also possible to ream away from the drill rig. In this case, reamers fitted into the drill string at the rig are rotated and thrust away from it. Pullback Pipe installation is accomplished by attaching the prefabricated pipeline pull section behind a reaming assembly at the exit point and pulling the reaming assembly and pull section back to the drilling rig. This is undertaken after completion of prereaming or, for smaller diameter lines in soft soils, directly after completion of the pilot hole. A swivel is utilized to connect the pull section to the leading reaming assembly to minimize torsion transmitted to the pipe. The pull section is supported using some combination of roller stands, pipe handling equipment, or a flotation ditch to minimize tension and prevent damage to the pipe. Buoyancy Control Uplift forces resulting from the buoyancy of larger diameter lines can be very substantial. High pulling forces may be required to overcome drag resulting from buoyancy uplift. Therefore, contractors will often implement measures to control the buoyancy of pipe 30 inches or over in diameter. The most common method of controlling buoyancy is to fill the pipe with water as it enters the hole. This requires an internal fill line to discharge water at the leading edge of the pull section (after the breakover point). An air line may also be required to break the vacuum which may form at the leading edge as the pull section is pulled up to the rig. The amount of water placed in the pipe is controlled to provide the most advantageous distribution of buoyant forces. Some contractors may choose to establish a constant buoyancy. This can be accomplished by inserting a smaller diameter line into the pull section and filling the smaller line with water. The smaller line is sized to hold the volume of water required per lineal foot to offset the uplift forces. To: Kyle Klatt, Senior Planner From: Rick Chase, Fire Marshal Date: 4-20-2016 Scope: Northern Natural Gas CUP 16-09 The following comments are provided regarding the above CUP proposal. 1. Provide complete emergency contact information of primary and secondary contact including e-mail prior to work commencing. 2. Have the field supervisor schedule a preconstruction meeting on site with the Fire Marshall prior to drilling operations. 3. Provide anticipated start and end date as it becomes available. 4. Provide a copy of all acceptances testing in digital format (Flash drive) upon project completion. Thank-you for the opportunity to provide comments on the proposed project if you have any questions please contact me. Sincerely, Rick Chase CC: Alan Strand, Building Official µCedar Station Upgrade Pipeline Project RouteDakota County, MinnesotaEasement Location MapDimensions are Approximate49,439 S.F.1.13 Acres143,018 S.F.3.28 Acres39,422 S.F.0.90 Acres17,188 S.F.0.39 Acres5,256 S.F.0.12 Acres3,343 S.F.0.07 Acres63,077 S.F.1.44 Acres125,886 S.F.2.88 Acres59,310 S.F.1.36 Acres80,035 S.F.1.83 Acres1,136 S.F.0.02 AcresLEGENDProposed PipelineParcel LinesProposed New EasementsExisting EasementsTemporary EasementsDrill Location11,600 FEET Total Length (ROSEMOUNT)76,362 S.F. / 1.73 Acres904,839 S.F. / 20.72 Acres510,748 S.F. / 11.69 Acres µCedar Station Upgrade Pipeline Project RouteDakota County, MinnesotaEasement Location MapDimensions are Approximate3,919 FEET1298 FEET160 FEET1 ,7 5 5 F E E T 1,548 FEETLEGENDProposed PipelineParcel LinesDrill LocationProposed Drilled PipeProposed Trenched Pipe11,600 FEET Total Length (ROSEMOUNT)8,680 FEET of PIPE Drilled2,920 FEET of PIPE Trenched µCedar Station Upgrade Pipeline Project RouteDakota County, Minnesota Easement Location Map Dimensions are Approximate 3,919 FEET 1298 FEET 160 FEET 1,7 5 5 F E E T 1,548 FEET LEGENDProposed PipelineParcel LinesDrill LocationProposed Drilled PipeProposed Trenched PipeTree Location 11,600 FEET Total Length (ROSEMOUNT) 8,680 FEET of PIPE Drilled2,920 FEET of PIPE Trenched (118) Trees Impacted / (20) Trees Removed Approximate Numberskj Excerpt from the April 26, 2016 Planning Commission Minutes 6.a. -09-CUP). Senior Planner Klatt summarized the staff report for the Planning Commission. Commissioner Henrie inquired how deep underground the pipe would run and if neighboring residents would feel any impact. Klatt deferred to the applicant. Commissioner Clements inquired what extended hours meant, is that extra 2 hours or half a day. Klatt stated it depends on where they are in the process. He noted that once the Northern Natural Gas commences with the installation of pipe, stopping can be problematic since it greatly increases the risk of the pipe getting stuck. Brian Krueger from Northern Natural Gas was on hand to answer questions. He stated drilling will take place in excess of 20 ft. deep, but will need to resurface at tie in points. Soil samples will be taken to determine soil conditions and design the drill to avoid tremors. The drill noise will stay under 55 decibel mandated by city code, if it does exceed they have ways to mitigate the noise. If stopped in the middle of process. It will take about a day to day and a half to have piping completely pulled through. The need for the additional piping is to increase flow and to provide the needed supply to meet the increased demands from their contract Xcel Energy. Commissioner Clements inquired how far apart the new pipe will be placed from the existing pipe. Krueger stated it will be about 25 feet but that it may be somewhat closer in some locations where there is less room within the existing easement. Chair Kenninger inquired about the largest pipe chase and how many residents would be impacted and how long the process will take. Krueger stated that most of the sound will be at entrance points. Pulling the pipeline needs to be continuous and could exceed the 55 decibel range in some locations. They are testing to see how far noise would be heard. In areas where the sound will exceed 55 decibels a sound buffer would be put up. He is unsure of the number of landowners impacted. Commissioner Clements encouraged open communication with residents about impact of the drilling and pipe installation. Commissioner Henrie inquired if there is a time line for each pipe chase. Krueger stated that no schedule is set yet but would most likely start with longer drills. He predicted that at most they would be working for a month or two at each location. Henrie also wondered if approval is contingent upon other cities also approving the project. Klatt stated that federal law preempts local ordinances and that the City cannot deny a request for a pipeline company to work within an existing easement. The City may add conditions to the permit in order to protect the welfare of the public. Chair Kenninger requested information concerning how loud 55 decibels is compared to other activity. Klatt stated that this amount is typically associated with ambient noise levels like traffic. The public hearing was opened at 7:08 pm. Public comments: Mark Schroeder, 12535 Dodd Blvd, stated that he is not exactly sure where the pipeline will cross his property and that he would also like clarification concerning how the project will proceed. He also questioned whether or not the proposed easements across his property would affect his property value. MOTION by Henrie to close the public hearing. Second by VanderWiel. Ayes: 4. Nays: 0. Motion Passes. The public hearing was closed at 7:11 pm. Additional Comments: None that the city is not acquiring easements. The easement is an agreement between the applicant and property owner. Motion by VanderWiel to recommend the City Council approve the Conditional Use Permit for Northern Natural Gas, subject to the following conditions: 1. Submittal and approval of a City Utility Permit from the City Engineer. 2. All construction and restoration activities shall conform to the City of Rosemount General Specifications and Standard Detail Plates for Street and Utility Construction. 3. Construction hours outside of those specified in City Code Section 9-7-2 are permitted provided the extended hours are necessary to complete horizontal directional drilling work for long runs that cannot be completed during the permitted construction time period. The applicant shall provide advance notice to the City when activities will extend beyond the working hours specified by the City Code. 4. Northern Natural Gas Company shall limit construction noises from horizontal directional drill activities to 55 dBA at any residential dwellings or will work with the resident(s) of said dwellings to temporarily relocate during construction activities. 5. 6. All infrastructure and landscaping removed from City property shall be restored and replaced upon completion of the pipeline project, including a one year warranty period. A letter of credit for 110% of the value of the infrastructure and landscaping shall be submitted to the City prior to work commencing. 7. NNG shall submit an updated map book to the City similar to the maps provided with its Federal Energy Regulatory Commission filing showing the location of the existing and proposed pipeline prior to construction. 8. The Conditional Use Permit shall be valid through the projected completion date of October 31, 2017. Second by Henrie. Ayes: 4. Nays: 0. Motion Passes.