May 2022
Transmission line construction on all segments is complete, including nearly 20 miles of new 230 kV transmission infrastructure installed. Crews plan to energize the line later this summer, after substation construction is complete.
Xcel Energy continually invests in systems that strengthen the region’s electric system, improve service reliability and meet the current and future needs of customers across Colorado. The Northern Colorado Area Plan is part of our comprehensive, long-range plan and commitment to provide safe and increasingly clean electricity for all customers.
Xcel Energy is modernizing the electric system by replacing the existing 44 kilovolt (kV) transmission infrastructure with new, higher-voltage (115 kV and 230 kV) transmission lines between the Western Area Power Administration (WAPA) Ault Substation and Xcel Energy’s existing Cloverly Substation. The project also includes two new electrical substations and improvements to two existing substations. The planned improvements will reliably serve existing and future customers and meet growing and changing energy needs.
Transmission line construction on all segments is complete, including nearly 20 miles of new 230 kV transmission infrastructure installed. Crews plan to energize the line later this summer, after substation construction is complete.
In February 2019, the Town of Ault approved the site plan for the Husky Substation to replace the existing Ault 44 kV Substation, which will be decommissioned after the Husky Substation is energized. Construction began on the Husky Substation in December 2021 and should be completed in late 2024.
The proposed Ault to Cloverly Transmission Project, another component of the Northern Colorado Area Plan, was approved by Weld County and the Town of Eaton in 2022 and construction will begin in spring 2023.
On March 1, 2018, the Colorado Public Utilities Commission approved the Certificate of Public Convenience and Necessity (CPCN) application for the Northern Colorado Area Plan. The CPCN approval allows Xcel Energy to move forward with the siting and permitting of project components included in the Plan.
Transmission lines are a vital link used to deliver electricity over long distances from power sources (generation) to transmission substations closer to homes and businesses. A strong transmission system guarantees reliable electricity. Utilities connect their transmission systems to neighboring systems run by other utilities. These interconnected systems form regional grids that allow power to flow from one area to another, ensuring reliable and efficient electric delivery to customers, even during emergencies.
The flow of electricity cannot easily be controlled, and it cannot discriminate between generation sources. Instead, power follows the path of least resistance and carries power derived from diverse resources, such as wind, solar, natural gas, and coal.
Electricity also cannot be stored; it must be generated, transmitted, and distributed for immediate use. Traveling at almost the speed of light – 186,000 miles a second – electricity arrives where it’s demanded at almost the same time it’s produced.
Regional transmission organizations (RTOs) ensure reliable power supplies, adequate transmission infrastructure, and competitive wholesale electricity prices.
In Colorado, the Colorado Public Utilities Commission (CPUC) regulates utilities to ensure reliable electricity delivery.
Public Service Company of Colorado (PSCo, a subsidiary of Xcel Energy) provides electricity and natural gas to customers in Colorado. The service area of PSCo covers more than 8,200 square miles, with 4,615 miles of transmission.
Electric utilities consider the following factors when deciding whether to construct transmission facilities above ground or bury them.
Xcel Energy designs, constructs, operates, and maintains its transmission lines and substation facilities to meet or exceed the requirements of the National Electric Safety Code (NESC), United States Department of Labor occupational safety and health standards, and our own power system safety standards. The company provides a maximum degree of safety and protection for the landowner and landowner’s property, the public, and our own employees.
There are land-use activities that are allowed on power line rights-of-way, if the activities do not interfere with operation and maintenance of the power line.
Normal farming activities are permitted if reasonable care is taken to prevent damage to power line structures from farm machinery. Lines are designed to allow safe operation of 14-foot-high (including antennas) farm machinery underneath the wires.
Machinery and Vehicle Guidelines
One of the most important rules to follow when working around power lines with tall equipment is simple. LOOK UP. Know where the power lines are and stay away from them.
Building or Planting Guidelines
The North American Electric Reliability Corporation (NERC) requires electric utilities to meet stringent requirements designed to keep our electric system safe and reliable, including standards for maintaining proper clearances. It is the utility’s responsibility to keep a certain amount of distance around power lines clear of anything that may make contact or near-contact with a power line. This includes buildings and incompatible vegetation.
Trees or other vegetation that could grow into or fall across the conductors may have to be trimmed, topped, or removed. You must call your utility provider before planting any trees or shrubs, or building any structures in power-line right-of-way areas to help avoid problems in the future.
Fence guidelines
Fence wires mounted on weed posts can build up an electrical charge near power lines. Important factors are:
Irrigation and Watering Guidelines
The potential for water and metal to conduct electricity makes it important to take safety precautions when irrigating near power lines. Additionally, fertilizers and pesticides tend to increase conductivity of water, making extra precautions necessary. Watering the lawn at your home or business is not problematic; however, you still must prevent a direct, solid stream of water from contacting the power line.
Recreation Guidelines
Safe Construction and Maintenance Practices
Birds and Power Lines
Xcel Energy uses several strategies to reduce the number of birds that are injured or killed when they contact power lines or electrical equipment. The strategies are:
For additional information regarding birds and power lines, visit the Avian Power Line Interaction Committee website at www.aplic.org.
If you are considering operating a vehicle within a height greater than 14 feet, contact your local utility company. Call first, even if it appears the line has clearance exceeding 14 feet. And always remember:
Electric fences, being specially insulated from the ground, can pick up a charge from power lines. Usually, the charge will drain off when the charger unit is connected to the fence; however, when the charger is disconnected either for maintenance or when the fence is being built, a small shock may be produced. Call Xcel Energy for assistance. Typically, symptoms such as shock can be prevented by:
Yes, as long as you take these precautions:
No. Here are some easy rules to follow:
No. Fires should not be started under a power line. Smoke and hot gases from fires can create a conductive path for electricity.
Xcel Energy follows strict power line maintenance standards. Power lines are inspected regularly (usually during fall or winter months) and by air to look for the following:
Utilities must visit the right-of-way for these inspections, but visits may be minimal, and landowners will be contacted prior to inspections or maintenance. However, in cases of emergency, advance contact may not be possible.
Electrocution of birds typically is not associated with transmission lines greater than 138 kilovolts (kV) because generally the electrical components are separated enough that a bird can avoid contact with two of them, which would fatally complete a circuit. Problems that do arise can be corrected in two primary ways:
There are measures that can be taken before construction and after construction.
Pre-construction efforts
Post-construction efforts
Marking lines
Marking lines with various types of markers can decrease but not eliminate bird collisions. The different types of markers vary in effectiveness. Devices include bird and swan flight diverters and clamp-on markers. Xcel Energy has used a variety of these markers on its lines. The decision to use them is based on:
Electric fields are created by voltage. The voltage on an electric wire is caused by electric charges that can exert force on other nearby charges. Electric fields are found near any electric device that is plugged in, even if it not operating. For instance, plugging an appliance such as a lamp or hair dryer into a wall socket applies the voltage to the cord, which is then surrounded by an electric field. Electric fields are strongest closest to the source, and the higher the voltage the stronger the field.
Magnetic fields are created by current. When charges move they produce an electric current that can exert forces on other electric currents. For instance, turning on an appliance, such as a lamp or hair dryer creates a flow of current, which causes a magnetic field. Magnetic fields are strongest closest to their source and are higher when more current is drawn.
EMF is found everywhere electricity is used. Household appliances such as hair dryers, electric blankets, and blenders produce EMF. Office equipment such as computers and copy machines produce EMF. Even the earth has its own magnetic field. In normal everyday life, it is impossible to avoid electric and magnetic field exposure. EMF is everywhere in our environment and occurs in nature as well. Field levels from household appliances and office equipment are about the same or greater than those fields found near power lines.
Radio waves, microwaves, and X-rays are different and more powerful forms of electric and magnetic energy and should not be confused with the power frequency EMF addressed here.
Anything that generates, distributes, or uses electricity creates EMF. Figure 1 is a list of some appliances and machines commonly found in homes or offices and the magnetic field levels found nearby.
We also encounter a wide variety of EMF in other ways―natural and man-made. The earth’s atmosphere creates slowly varying electric fields, and thunderstorms produce very intense electric fields that are occasionally discharged by a lightning bolt. The earth’s core produces a steady magnetic field, as can easily be demonstrated with a compass needle which points to magnetic north. This magnetic field has a strength of about 550 milligauss (mG).
Magnetic fields from the earth or from small magnets exert forces on electric currents or on other magnetic objects, as when a compass needle points toward a nearby magnet. Magnetic fields are common in our lives. Many children’s toys contain magnets and many of us use refrigerator magnets, generating fields of about 100,000 to 500,000 mG.
An increasingly common diagnostic procedure, magnetic resonance imaging (MRI), uses fields of about 20,000,000 mG. If you were to spin a magnet at a rate of 60 times a second, you would get an alternating magnetic field like the fields produced by power lines.
Figure 1. Typical 60 hertz magnetic field levels from some common home appliances
Magnetic field 6 inches from appliance (mG) | Magnetic field 2 feet away (mG) | |
---|---|---|
Electric shaver | 100 | - |
Vacuum cleaner | 300 | 10 |
Electric oven | 9 | - |
Dishwasher | 20 | 4 |
Microwave oven | 200 | 10 |
Hair dryer | 300 | - |
Computers | 14 | 2 |
Flourescent lights | 40 | 2 |
Faxogram machine | 6 | - |
Copy machines | 90 | 7 |
Garbage disposals | 80 | 2 |
Source: National Institute of Environmental Health Services/National Institutes of Health: EMF Associated with the Use of Electric Power
Exposure levels vary from individual to individual and from home to home, but a study by the Electric Power Research Institute (EPRI) puts the background levels of power line magnetic fields in the typical United States home at between 0.5 mG and 4 mG with an average of 0.9 mG. Levels rise the closer you get to the source of the field. Most people are exposed to greater magnetic fields at work than in their homes. See Figure 1.
Figure 1. Typical 60 hertz magnetic field levels from some common home appliances
Magnetic field 6 inches from appliance (mG) | Magnetic field 2 feet away (mG) | |
---|---|---|
Electric shaver | 100 | - |
Vacuum cleaner | 300 | 10 |
Electric oven | 9 | - |
Dishwasher | 20 | 4 |
Microwave oven | 200 | 10 |
Hair dryer | 300 | - |
Computers | 14 | 2 |
Flourescent lights | 40 | 2 |
Faxogram machine | 6 | - |
Copy machines | 90 | 7 |
Garbage disposals | 80 | 2 |
Source: National Institute of Environmental Health Services/National Institutes of Health: EMF Associated with the Use of Electric Power
Because magnetic fields are not shielded by ordinary materials, burying power lines won’t keep the fields from passing through the ground. In fact, underground lines can produce higher levels of magnetic fields directly above the line at ground level because these lines are located closer to you (5 feet below) compared to overhead lines (25 to 30 feet above). However, the strength of the magnetic field from underground lines falls away more quickly to the side with distance than from overhead lines because of the way the lines are built.
Compared to overhead lines, underground lines are significantly more expensive to install (up to 10 to 20 times more expensive), more difficult to repair and can have greater environmental impacts because of the disturbance of the soil to install the underground lines. Since recent research results provide no conclusive connection between EMF exposure and health effects, burying lines isn’t a reasonable alternative.
There are no federal standards limiting residential or occupational EMF exposure. Several states have set standards for the allowed level of magnetic fields from new power lines. The Colorado Public Utilities Commission has determined that magnetic fields for new power lines of 150 mG or less are reasonable at the edge of the right-of-way. Other states have established similar standards of 150 to 200 mG for new transmission power lines.
The EMF levels produced by appliances vary from manufacturer to manufacturer and model to model. The designs of many newer model appliances, in general, often produce lower fields than older models. An example is electric blankets where new blankets produce much lower fields than those produced 20 years ago. There is no federal certification program on EMF levels so beware of advertisements on appliances making claims of federal government certification of low or zero EMF levels.
The issue has been studied for more than 40 years by government and scientific institutions around the world. The balance of scientific evidence indicates exposure to EMF does not cause disease.
EMF Sources and Useful Links
The following are links to more information (and Denver area) studies on electric and magnetic fields:
High levels of power line EMF can interfere with a pacemaker’s ability to sense normal electrical activity in the heart. Most often, the electric circuitry in a pacemaker might detect the interference of an external field and direct the pacemaker to fire in a regular, life-preserving mode. This isn’t considered hazardous and actually is a life-preserving default feature. There have been cases with dual-chamber pacemakers triggering inappropriate pacing before the life-preserving mode takes over. Newer pacemakers have been designed to be less susceptible to this type of interference.
The American Conference of Governmental Industrial Hygienists (ACGIH) issued guidelines for EMF exposure for workers with pacemakers or implantable defibrillators. Maximum safe exposure for workers with these medical devices at 60 hertz (the frequency of most transmission lines) is 1.0 G (1,000 mG) for magnetic fields and 1.0 kilovolt per meter for electric fields. Non-electronic metallic implants (artificial limbs, screws, pins, etc.) can be affected by high magnetic fields like those produced by MRI devices but are generally unaffected by the lower magnetic fields produced by most other sources.
If you wish to reduce EMF levels in your vicinity, you can do so by recognizing that your exposure is determined by the strength of the magnetic fields given off by things around you, your distance from the source of the field, and how much time you spend in the field. Creating distance between yourself and the sources of EMF is the easiest way to reduce exposure. Standing back―even an arm’s length away―from appliances that are in use is a simple first step. Remember, EMF decreases dramatically with distance. This is more feasible with some appliances than with others, but the following simple recommendations will help you reduce your EMF exposure at home:
Although conclusive results on the potential for health effects from EMF are not yet known, utilities typically take prudent actions in response to concerns about EMF. For example:
EMF Sources and Useful Links
The following are links to more information (and Denver area) studies on electric and magnetic fields:
In the early stages of construction, Xcel Energy employees and contractors will work within and around the utility’s right-of-way to perform field assessments and gather information that’s used to refine the vegetation and construction plan and minimize disturbance. Survey stakes and flagging will clearly mark easement boundaries and pole locations. Work zones will provide safety barriers for construction crews and the public. Vegetation and other obstacles, such as fences and objects that impede construction, are temporarily removed or relocated within or along the edge of the easement to allow for the safe construction, operation and maintenance of the transmission line.
Vegetation trimming, pruning and removal are conducted in two phases as the project progresses. The initial phase includes removing incompatible vegetation in and around the transmission line easement. This may include vegetation outside the easement that could pose a risk, such as dead or unstable trees that are close enough to strike a line or pole if they fall. After the transmission line is built and conductor is in place, a final vegetation assessment is performed to verify proper clearance.
We take thoughtful measures to protect yards and agricultural property around our construction area by installing temporary erosion-control measures to minimize ground disturbance and keep sedimentation, from potential stormwater runoff, from leaving the construction site. We also place composite mats or riprap to stabilize the ground at right-of-way entry points and silt fences, wattles and haybales along the right-of-way to control sediment runoff.
Large, heavy equipment, including cranes, excavators, flat bed trailers and bucket trucks, are used to construct and install new structures and conductor. On occasion, we may need to temporarily stop traffic to facilitate the safe delivery of materials and equipment on and off the jobsite, but these disturbances typically last only a few minutes.
Crews work to keep the project on schedule by concurrently working in multiple areas along a line segment. As a result, you may notice lulls in construction activity near your home while crews work in other locations. We strive to be a good neighbor, respecting local noise ordinances and working to limit noise-producing construction activities outside of normal business hours of 8 a.m. to 5 p.m. Local noise ordinances allow construction between the hours of 7 a.m. and 9 p.m. On occasion, our crews need the flexibility to work outside those hours to complete time-sensitive activities.
When construction is completed, inspections are conducted and restoration begins. The right-of-way will be cleared of construction materials and equipment and restoration activities will be performed.
We do not anticipate any disruption in your electric service during construction. However, unforeseen circumstances do arise at times and we must adjust our plans. Should a temporary outage become necessary to perform a portion of the work, Xcel Energy will notify you in advance.
Description
Build 4.4 miles of 230 kV double-circuit transmission line from the Western Area Power Administration (WAPA) Ault Substation to the new Xcel Energy Husky Substation. This transmission line will accommodate two, 230 kV circuits; however, only one circuit will be installed until additional electrical service is needed. Install fiber optic ground wire (OPGW) for length of the line.
The new Husky Substation will replace the Xcel Energy Ault 44 kV Substation, scheduled for decommissioning in summer 2024.
Construction Updates
Transmission line construction completed in the summer of 2023. Xcel Energy will collaborate with the Western Area Power Administration (WAPA) to connect Segment 1 to the WAPA Ault substation in the summer of 2024. The new transmission line will be energized once work at each substation is completed.
Description
Build 8.8 miles of new 115/230 kV double-circuit transmission line from the new Husky Substation to the new Collins Street Substation. This transmission line will accommodate one 115 kV circuit and one 230 kV circuit; however, only the 115kV circuit will be installed until additional electrical service is needed. Installation will include fiber optic ground wire for the length of the line.
Construction Updates
Transmission line construction completed in February of 2024. Physical construction is complete at Husky Substation. Crews will continue to install/connect cable and control-work components through the summer of 2024. The new transmission line will be energized once work at each substation is completed.
Description
Build 5.9 miles of new 115/230 kV double-circuit transmission line from the new Collins Steet Substation to the Cloverly Tap near 31510 County Road 41. This transmission line will accommodate one 115 kV circuit and one 230kV circuit; however, only the 115 kV circuit will be installed until additional electrical is needed. Installation will include fiber optic ground wire for the length of the line.
Construction Updates
Transmission line construction completed in April of 2024. Work at the Collins Street Substation began in April 2023. Grading, foundations, and physical construction are complete. Crews will continue to install/connect cable and control-work components through the summer of 2024. The new transmission line will be energized once work at each substation is completed.
Description
Remove 1.01 miles of existing 44kV transmission line conductor and replace with new 115 kV conductor from the Cloverly Tap near 31510 County Road 41 to Weld County Road 43. Various equipment upgrades will take place inside the fence at the existing Cloverly Substation.
Construction Updates
Transmission line construction completed in April of 2024. Physical construction upgrades at the Cloverly Substation were completed in October of 2023 and activities inside the substation’s control house will continue through the summer of 2024. The new transmission line will be energized once work at each substation is completed.
Xcel Energy is reaching out to the public in communities crossed by the project area to inform you of construction progress and help answer questions. Please visit this website to view videos about the project, review answers to frequently asked questions, and read up-to-date project information. Additionally, during construction, Xcel Energy will periodically email newsletters and/or project updates to landowners on the email list. Click here to join the email list.
Xcel Energy maintains a telephone information line (888.678.7640) and email address (NORTHERNCOLORADO@XCELENERGY.COM) to receive questions and comments.
Xcel Energy developed a comprehensive planning process that integrated public outreach and community meetings to gain public input for consideration in the planning process. A Community Working Group (CWG) was established, comprised of local citizens with diverse interests, to work with the project team throughout the planning studies.
The Xcel Energy project team reviewed public comments, land uses and environmental characteristics of the study area and developed a planning approach that considered constraints and opportunities for siting the new Collins Street Substation and routing the new 230-kV transmission line from the WAPA Ault Substation to Cloverly Tap.
Videos and materials from the public Open House meetings are available below in the “Public Open Houses and Community Working Group” accordion. Historic public outreach activities are captured in the below downloadable timeline graphic.
CWG Meeting #1, held in-person November 5, 2019
CWG Meeting #2, held in-person January 16, 2020
CWG Meeting #3, held virtually May 28, 2020
CWG Meeting #4, held virtually July 16, 2020
CWG Meeting #5, held virtually April 28, 2021
Public Open House #1, held in-person November 13, 2019
Public Open House #2, held in-person January 28, 2020
Public Open House #3, held virtually June 11 and 17, 2020
Public Open House #4, held virtually September 22 and 30, 2020
Public Open House #5, held virtually May 19, 2021
OPEN HOUSES MATERIALS
Public Open House #1 Materials – November 13, 2019
Public Open House #2 Materials – January 28, 2020
Public Open House #3 Displays – June 11 and 17, 2020
Public Open House #3 (Virtual) – June 17, 2020 (English)
Public Open House #3 (Virtual) – June 17, 2020 (Español)
Public Open House #3 (Virtual) – June 11, 2020 (English)
Public Open House #3 (Virtual) – June 11, 2020 (Español)
Public Open House #3 (Virtual) Presentation – June 11 and 17, 2020
Public Open House #4 (Virtual) – September 22, 2020 (English)
Public Open House #4 (Virtual) – September 30, 2020 (English)
Public Open House #4 (Virtual) Question & Answers September 22, 2020
Public Open House #4 (Virtual) Question & Answers September 30, 2020
Public Open House #4 (Virtual) Presentation
Public Open House #4 (Virtual) Mailer
Public Open House #5 (Virtual) Recording – May 19, 2021 (English)