Frequently Asked Questions

Project Description and Need

Why is the Project needed and what are the benefits to me?
Increasing electric load growth in the San Juan Basin region of Colorado and New Mexico in residential, commercial and industrial sectors has put a strain on the existing electrical system. The line will relieve regional transmission constraints, serve new loads, increase reliability and offer economic development opportunities by providing a pathway for renewable energy.

Transmission lines do not stop at state boundaries; they are part of a regional system that serves a greater population. Although the Project is being constructed to mainly serve loads in Colorado, other residents in the region will benefit from increased reliability. Equipment installed as a part of the Project will improve the reliability of an existing transmission path between Colorado and New Mexico by controlling the power flow in the line. Other benefits to the San Juan region of New Mexico include tax revenue from the installed facilities and Tri-State personnel presence in the area to maintain the installed equipment.

It should be noted that the nature of the national and regional electrical grid is one of source and delivery point homogeneity. The electrical grid functions and operates in connectivity with all generation sources at any given time, in essence as one mixed source once electrons unite within the grid. Paths are not isolated or specifically identified. The electrons in the grid flow simultaneously with no distinct origin or destination. Contributing to the reliability in another region is a requirement held by all who use electricity from the grid. Therefore, it is difficult to cite why one region should support the reliability of another region because of the nature of shared cooperative support of the grid system as a whole.

It should also be noted that residents in the San Juan region of New Mexico could receive electricity from sources based in Colorado and other neighboring states as power flows from out of state sources into New Mexico.

Region-wide Benefits

  • Provides power for new and increasing loads such as oil and gas development and future residential growth
  • Relieves constraints in regional transmission paths
  • Provides an additional pathway to provide electricity for future economic development opportunities in the area
  • Strengthens the regional grid from which New Mexico draws power

Why not just build a natural gas plant in Colorado to serve the need up there? How do you know this transmission line is the right solution to your needs?
In planning new additions to the power system, utility planners use a collaborative approach to evaluate the best solution to electric system needs. Transmission solutions are only one category of system alternatives that are explored. Others include generation alternatives (building a new power source), demand side management (energy conservation), energy efficiency improvements, etc. For this particular purpose, a transmission line from Shiprock to Ignacio was determined to be the best solution to the meet the purpose and need for the Project by relieving transmission constraints and serving increased loads.

The issue is not the need for additional electrical generation. The power exists in the Tri-State system. A new transmission line will provide the means for improving service to residential and industrial customers by redistributing electricity currently generated by the Tri-State fleet in New Mexico and Arizona with no additional air quality impact. The various industrial emissions sources in the Four Corners region are under a lot of scrutiny as can be seen by past action to require the San Juan Power Plant to install new air emission equipment, the electrification of more of the gas wells in Colorado, and recently to have the Four Corners Power Plant improve its air emission equipment. The proposal to build a natural gas plant could worsen regional air quality that a lot of people are trying to improve. The proposed transmission line does not require new generation source but will utilize existing installed resources.

Would Tri-State add another line or upgrade this line in the future?.
Tri-State does not anticipate the need to upgrade or add another line in the foreseeable future. But certain segments of the proposed line do follow corridors that have potential for future development. Extra care has been taken in the planning and design of the line to accommodate these future needs by building certain line segments in double-circuit configuration. By configuring the line in this manner, a future need for the second circuit will allow for minimal construction disturbances to accomplish a potential future increase in capacity.

How would the proposed Project benefit the regional electric system?
The regional electric grid is similar to a roadway system consisting of interstate highways and local roads. High-voltage transmission lines serve as electric highways, moving bulk electricity over long distances. High-voltage electricity is converted to lower-voltage electricity at substations. Distribution lines are comparable to local roadways, moving lower-voltage electricity from substations to residential and business consumers. Electricity moves freely on the regional transmission grid, similar to cars on a roadway system. The proposed transmission line, if built, would provide another electric highway to relieve congestion between Colorado and New Mexico.

Regional benefits are evaluated in terms of the Total Operating Transmission, or TOT. The Project area involves the TOT2A path, as well as others such as TOT3 and TOT5 paths. These TOTs are constrained transmission paths recognized by the North American Electric Reliability Corporation (NERC) and the Western Electricity Coordinating Council (WECC). The proposed line would create another transmission path in the area and relieves electric transfer congestion between Colorado and New Mexico. Transmission Operating Standards, such as NERC TOP-007-WECC-1, recognize the operating limits defined in the WECC Path Catalog for TOT2A (read back page of fact sheet). This path is limited to a maximum of 690 megawatts of flow to the south from west-central Colorado to New Mexico, less any load in southwest Colorado. As the load in southwest Colorado increases, the amount of transmission capacity available to transmit power between west-central Colorado and New Mexico decreases.

The proposed San Juan Basin Project would remove part of the load served from the existing lines that comprise TOT2A. Tri-State, as well as the other transmission owners of TOT2A, complies with NERC/WECC standards. Tri-State could be fined if the operating limits for TOT2A are violated.

What is the Project schedule?
The Project could be in-service by December 2015 provided the following general estimates of Project milestones are met:

  • National Environmental Policy Act (NEPA) process kicked off October 2009 with scoping meetings
  • Routing studies will be completed by fall/winter of 2010
  • Additional NEPA scoping meetings held in late 2010 for kick-off of the Environmental Impact Statement (EIS)
  • NEPA Record of Decision published by 2013
  • Permitting of all transmission lines, new easements executed and substation land acquired and completed by 2014
  • Substation construction in 2015
  • Transmission line construction beginning in 2014 with construction completed in 2015
  • Final transmission line connections and substation commissioning and energization by December 2015
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Electric Customer and Social Impacts

Would my electric service improve?
The transmission system is constantly maintained and monitored to serve customer load 100% of the time without service interruption or degradation; therefore, the end-consumer does not often experience problems with service. Tri-State along with its member co-ops constantly monitor load on lines and equipment and plan into the future trying to anticipate when and where the system may come under stress. Through this ongoing forecasting and planning, additions, improvements and changes to the system can be made to keep up with growth and continue to provide consistent reliable power to consumers. The proposed transmission line would add to the reliability of the existing system in Colorado and New Mexico, reducing the potential for outages and resulting in overall system improvement.

What are the likely socioeconomic benefits of this Project?
Socioeconomic impacts will be fully evaluated in the EIS. By providing a more robust transmission system for delivery of electric power and a support for economic development, including renewable energy systems, the entire region would likely benefit from the proposed Project.

Fiscal impact analysis estimates the direct public revenues and public costs resulting from the Project. The Project may generate a broad array of public revenues ranging from sales tax, property tax, franchise fees, licenses and permits and other charges for services. The ongoing tax revenues from the Project would benefit the region and its residents.

Local governmental units assess property taxes to fund public school operations and local government services. These local governmental units include counties, cities, school districts and special districts ranging from library districts to recreational districts to water districts.

Potential annual property tax revenue will be calculated based on the total assessed value of the transmission improvement Project.

Will local labor be employed to construct the line?
Electric transmission line and substation construction requires a concentration of specialized labor for a short period of time. Due to the nature of transmission line and substation construction, Tri-State does not use internal staff but regularly hires contractors to perform this work. Contractors will be used by Tri-State to construct the Project. Contractors usually bring with them a specialized work force to perform the required work but can, at times, hire local people to supplement. This decision is up to the contractor and their business practices. Local businesses can benefit from the project by providing equipment and materials, in addition to the typical lodging and meals associated with a workforce that is working out of town for a defined period of time.

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Landowner/Easement Questions

What is an easement?
An easement grants an entity the right to use the real property of another for a specific purpose while ownership to the underlying land is retained by the original owner for other purposes. Tri-State would acquire the easements required for the new transmission line. The easement agreements would identify Tri-State as the grantee. If located on private lands, substation sites are purchased by Tri-State and thus owned in fee.

What if a landowner refuses to grant an easement?
Before applications to city and county agencies are submitted, it is Tri-State's primary objective to work closely with local landowners and businesses to determine the best routing options. Landowner participation and feedback is welcomed. Real property and land rights acquisition would comply with the Colorado Code 38-1-101, (N.M. Stat. Ann. § 42A-1-6) which requires utilities to negotiate in good faith. Tri-State does have the power of eminent domain, but works diligently to avoid the need for such proceedings.

What impact would the Project have on property values?
Impacts to property values are highly variable because there are many factors that have the potential to affect real estate values. The current state of the economy, utility service, natural and man-made setting, and proximity to services and recreation opportunities are a few examples of variables that might impact property values. The physical attributes of any particular home also affect the value of the property. Property attributes that might be viewed as valuable by one buyer may not be as attractive to the next buyer. For example, a single individual with no children may not find a house in close proximity to a school as a selling point while at the same time a family is not likely to find value in a loft-style apartment in the middle of the entertainment district in a large city. Consideration of market trends is also of importance as the perceived value of a house can vary significantly based on whether home sales are trending up or down in any given year. All of these factors combined with others not discussed here make it very difficult to estimate the potential impact a transmission line may have on property values.

How is compensation determined? What compensation can a landowner adjacent to the easement expect to receive?
Tri-State will compensate the landowner for impacts of the easement using general industry guidelines. Easement negotiations begin after a project has been approved by authorized agencies and a final route identified. A Tri-State right-of-way acquisition and/or contracted real estate representative will work with property owners during the acquisition and negotiation process. The compensation to the landowner for the easement is based on the fair market value of the property following statutory and legal guidelines as applicable. The real estate discussions with the landowners during the easement acquisition process address issues including, but not limited to, the final determined length and width of the right-of-way; the number of structures as it pertains to the property in question; the height and design of the structures; the height, number and voltage of the wires; right-of-way clearing and construction practices; the project schedule; post-construction maintenance and right-of-way access; reasonably foreseeable damage settlements and vegetation management.

In addition to compensation for the easement, Tri-State will compensate the property owner for any crop damage and/or physical damage to property resulting from the construction and/or maintenance of the transmission line.

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Engineering and Design

What is the Transmission Line Design?
Project characteristics are described below.

Segment - Shiprock to Kiffen Canyon
Approx. Length (mi) Voltage (kV) Structure Type Structure Height (ft) Span (ft) Right of Way (ft) Number of Structures per mile Equipment Clearance*
30 230 double circuit Steel lattice and mono pole 100 - 150 800 - 1,200 150 4 - 6 28 / 14


Segment - Kiffen Canyon to Iron Horse


Double-Circuit 230 kV

Single-Circuit 230 kV

Design Component Steel Lattice Structure Steel Mono-Pole Structure Wood H-Frame Structure
Typical right-of-way width (feet) 150 150 150
Typical distance between structures (feet) 800 - 1,200 800 - 1,200 800 - 1,100
Typical structure height (feet) 100 - 150 100 - 150 65 - 100
Typical number of structures per mile 4 - 6 4 - 6 4 - 7
Ground clearance (beneath conductor under maximum operating conditions) (feet) 28 28 28
Minimum clearance of equipment to energized conductor (feet) 14 14 14

* Clearances would be maintained in accordance with the latest version of the National Electric Safety Code.

Why are you using a combination of lattice and mono poles on the double-circuit portions of the line?
Lattice structures are typically used for long-span construction and in mountainous terrain. Lattice structures have an open frame appearance that can mitigate visual impacts of the line at a distance. The lattice structures that will be used for much of the Project are typically made of galvanized steel, which has a dull finish that is not reflective and is muted against many different types of backdrops such as hillsides or wooded areas. Also, lattice structures require four relatively smaller foundations and can be assembled in sections.

Mono pole structures use one relatively large foundation that actually results in a smaller overall footprint on the ground. Mono pole structures may have a weathering steel finish that mimics the visual characteristics of a standard wood pole. The smaller footprint is useful when spotting structures in agricultural fields and congested rights-of-way with other buried utilities.

The use of wood structures is not practical on the double-circuit segments of the line because of the strength limitations of the wood. Double-circuit construction with wood poles would require two different sets of structures on a wider right-of-way having a smaller span. Wood H-frame structures will be used, however, on the single-circuit portions of the transmission line alignment.

Can structures be lowered to minimize the visual impact?
Structures are only as tall as they need to be to support the wires and to comply with all safety and operational requirements. Shorter structures result in a higher number of structures per mile, often resulting in more visual impact.

Can you bury the line?
It is Tri-State's policy not to bury transmission lines because underground lines are significantly more expensive, harder to maintain and result in greater construction impacts to the environment. They can range from 4 to 15 times the cost of overhead construction, with the cost multiplier generally rising as the voltage level increases and the construction difficulty increases. However, if the landowner/developer/jurisdiction pays for the differential in cost, and if the feasibility analysis shows that it can be safely constructed and operated underground, a request to bury a line would be considered.

What is EMF and what would it be for this Project?
EMF stands for electric and magnetic fields. Electric fields are produced whenever a conductor is connected to a source of electrical voltage. An example of this is the plugging of a lamp into a wall outlet in a home. When the lamp is plugged in, a voltage is induced in the cord to the lamp that causes an electric field to be created around the cord. Magnetic fields are produced whenever an electrical current flows in a conductor. In the lamp example, if the lamp is turned on, allowing electricity to flow to the lamp, a magnetic field is created around the lamp cord in addition to the electric field. On this Project, magnetic fields at the edge of the right-of-way are expected to be less than 30 milliGauss, which is similar to exposure from a computer monitor or color television.

Will the transmission line produce noise?
Several factors produce audible noise on high voltage transmission lines. The higher the voltage on the transmission circuit is, the greater the potential for corona activity on the line. Corona is what creates the hissing, crackling or random popping sound. Corona is a small electrical discharge, not unlike the static electrical charge that a person may experience when touching a metal object when walking on carpeting. Corona can increase in wet weather, when water droplets form on a transmission line. All high voltage transmission lines experience some corona during wet weather. In fair weather conditions, corona and its corresponding audible noise are usually at low levels.

Substation and transmission line materials are designed according to industry standards to minimize noise. During installation, construction workers will take care in ensuring that the conductor surface is not scratched so as to minimize potential for audible noise. For a 230-kilovolt line, such as the one proposed, "corona free" hardware will be used to reduce even further the possibility of transmission line noise.

Would this interfere with the computer equipment, cell phones or radios?
Corona on transmission line conductors can generate noise at the frequencies at which radio and television signals are transmitted. This noise can interfere with receiving of these signals and is called "radio interference" and "television interference" depending on the frequency.

EMF resulting from modern transmission lines does not cause cell phone or landline interference. Older transmission lines that are not operating properly may cause interference. If this occurs, residents can call the utility to have the problem investigated.

Radio reception in the AM broadcast band (535 to 1605 kilohertz) is most often affected with what is commonly referred to as static. FM radio reception is rarely affected. Corona can affect the reception of the video (picture) portion of a television screen.

Corona effects from this Project are expected to be low enough so that no objectionable audible noise or radio or television interference would result outside the right-of-way. Transmission line maintenance activities are intended to locate and correct these problems as they occur. The line would use corona-free hardware to minimize noise.

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Construction and Maintenance

Would the structures interfere with irrigation systems?
Tri-State avoids known irrigation systems in routing the transmission line to the extent possible and mitigates impacts by placing structures at the edge of an irrigation system. These routing details can be evaluated with affected landowners.

How would the Project affect planting and harvesting seasons during construction? Is compensation offered for the crops? What happens if there is damage on my property due to construction?
Right-of-way agents would work with individual landowners to determine when to avoid construction during the planting and harvesting seasons. If damage to crops cannot be avoided, compensation for crop loss would be offered. Any damage to property would also be repaired or compensation will be given as appropriate.

How is livestock managed if you have to take down a fence? How will livestock be affected by the Project?
In coordination with the landowner, segments of fences may be removed or access gates may be installed during line construction. Crews would construct temporary fences and work with landowners to minimize impacts to livestock and their safety.

There is a potential for livestock to be affected by stray voltage that can be caused by improper wiring. In most cases, the voltage or the current flowing through the animal is too weak to harm the animal and is similar to the "shock" felt by a person touching a metal object after shuffling his or her feet on the carpet. This can occur when an animal touches a metal object near a transmission or distribution line, where the line may not be operating or grounded properly and the object may not be grounded properly. Correcting wiring problems and proper grounding for electric equipment and metal fences that are close to the transmission line will mitigate most problems.

How do you maintain vegetation in the ROW?
The primary objective of the transmission line clearance program is to keep transmission facilities clear of all tall-growing trees, brush and other vegetation that could grow too close to conductors. Removing tall-growing vegetation at the time of facility construction and maintaining this condition as part of routine maintenance activity best accomplishes these objectives.

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Siting and Environmental

When would the route be chosen and by whom?
The permitting process determines the final location of the line with input from the public and stakeholder agencies. This would be completed through a multi-step siting process that includes detailed analysis of resources within the Project study area and identification of opportunities and constraint areas for location of transmission facilities. Based on the opportunities and constraints analysis, preliminary alternative corridors and route options have been identified. The corridors are at least one mile wide to allow for flexibility in selecting alternative routes within them that can avoid the most sensitive areas, residences, etc.

Currently, we are conducting route refinement and alternative route analysis. Public and agency input is important to this process. The public will have an opportunity to review the route options and provide input to the route refinement process. A comparative analysis will be performed to help in selecting a preferred as well as alternative route(s) for analysis in the EIS and is expected to be completed in early 2011.

Where will the line be located?
The exact line location is not known at this time. Routing alternatives are currently under review and the route options currently shown on the Project maps are representative of the proposed centerline. Current routing options can be found here.

Won't the line ruin the local viewshed?
Whenever feasible, the line would be located to minimize visual impacts from residences, roadways and other areas. In areas where the topography allows, the transmission line structures can often be "tucked out of sight." In other areas, the line would be visible given a lack of screening options. As part of the NEPA environmental review, visual and aesthetic resources would be analyzed. Visual simulations of representative viewsheds have been prepared for this Project.

How much does the public influence the location of the line?
The public assists with providing local knowledge regarding characteristics and resources of the study area. The preferences of the public are taken into account along with other criteria including engineering needs, maintenance requirements, environmental resources and legal and economic considerations.

How will you address/disclose the environmental impacts from the transmission line?
An EIS will be prepared under NEPA guidelines. This document will describe the affected environment and expected impacts to various resources and land uses within proximity of the preferred and alternative route(s) chosen through the siting process. The Bureau of Land Management and cooperating federal agencies (Bureau of Indian Affairs, Rural Utilities Service and Western Area Power Administration) will oversee this process.

How would you minimize environmental impacts?
Tri-State would minimize environmental impacts largely by avoidance of sensitive resources and following existing disturbed corridors when feasible. When resources cannot be avoided completely, we would implement mitigation measures to minimize the impacts as much as feasible. The appropriate agencies will be consulted and guidance sought regarding mitigation measures for resources within their jurisdiction/areas of interest.

What kind of impacts would this Project have on air emissions in the area?
The Project would not increase any emissions from power sources or require new generation of power. The line would increase capacity to carry power that is currently being generated more efficiently throughout the region.

What is the source of the power that would be carried through the new transmission line?
Tri-State serves its members' loads with a combination of resources. Specific resources are not typically associated with specific loads. With changing system and market conditions, the resources used to serve specific loads can and do change from day to day and hour to hour. The generation resources that currently contribute energy to the regional transmission system and will contribute energy to the proposed line include existing Tri-State resources in Arizona, New Mexico and Colorado. These resources include Tri-State's shares of San Juan Generating Station Unit 3, Springerville Generating Station Unit 3, Pyramid Generating Station, Prewitt Escalante Generating Station, power purchases from Western that originate primarily from Glen Canyon Dam at Lake Powell, the Cimarron I Solar Facility and other resources whose energy is blended once it is injected onto the transmission system.

Tri-State intends to use existing generation to supply the target members' expanding loads via the proposed transmission line. We do not anticipate any substantive changes in operation of our generation fleet as a result of the Project, nor do we anticipate any increase in generation or development of any new sources of generation in order to serve member loads via the proposed Project.

Strengthening the Regional Grid
Details on how the proposed transmission line will interconnect with existing generation sources

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Health Concerns

Should I be concerned about any health risks associated with the line?
There has been considerable research devoted to the subject of health concerns and transmission lines over the past 30 years. Questions and answers prepared by the National Institute of Environmental Health Sciences (NIEHS) can be found on this website. In addition, the website contains an executive summary of the NIEHS report to Congress.

Some studies show a clear link to cancer and other ill health effects from electric and magnetic fields (EMF). How do you dispute these studies?
Considerable research and study has been done to investigate potential health effects of EMF from high-voltage transmission lines on living organisms. Based on evidence to date, no biological hazards have been identified from EMF produced by electric transmission lines. Nevertheless, the proposed transmission line would be designed to operate within the EMF parameters deemed reasonable by the Colorado Public Utilities Commission. The proposed transmission line would also be designed and constructed to meet or exceed all applicable requirements of the National Electric Safety Code.

The EMF associated with a high voltage transmission line occurs mainly on the transmission line right-of-way since the electric and magnetic fields surround the conductor and decrease rapidly with increasing distance from the conductor. Magnetic fields travel through most materials including iron, steel, lead and soil. Magnetic and electric field strengths drop rapidly as distance increases from the conductors such that at a few hundred feet from the line the fields are non-detectable. Depending on the flow of electrons, when there are two lines side by side, there can be cancellation of EMF. Current causes magnetic fields, not voltage. With a higher voltage, more power is delivered with less current.

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Project Benefits

The proposed project would:

  • Improve the power delivery infrastructure to Colorado and New Mexico's San Juan Basin
  • Increase the load serving capabilities for residential, small business, and industrial electric consumers (including oil and gas developers)
  • Relieve transmission constraints for the region
  • Provide a pathway for potential renewable energy development

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