South Jordan to Draper

Not every pole will be the same. Generally:

• Existing wood poles will be replaced with new wood poles.
• There are no additional poles. Poles will be installed in more or less (within a few feet of) the existing pole location.
• Pole heights will increase between about 2 and 40 feet (see below). The increase in pole height is driven by a) structures built near the line since originally installed, b) changes to national safety codes and standards, and c) the increase in voltage to 138kV.

North of 11400 South:

• Pole height difference varies by location. On average, the new poles will be around 30 feet taller than the existing poles. The largest change in height is around 40 feet and the smallest change is around 2 feet taller.

Along 11400 South and south of 11400 South:

• Pole height difference varies by location. On average, the new poles will be around 15 feet taller than the existing poles. The largest change in height is around 20 feet and the smallest change is 10 feet taller.

No, Rocky Mountain Power is only replacing the existing poles.

Maybe. There may be opportunities to adjust pole placement in line with the current alignment. In fact, we have already coordinated with a few property owners to move the pole to a location the property owners find more favorable. The poles are generally where they must be located to support the line, but where feasible and the pole will not change from one property to another, we will work with residents to adjust pole placement within a couple of feet of an existing pole.

Please contact us if you would like to discuss whether this is feasible on your property.

North of 11400 South, three additional power wires are planned on the line.

Along 11400 South and south of 11400 South, no additional power wires are planned on the line.

Yes. The existing easements provide for the installation and operation of transmission, distribution, and communications lines, without limits on voltage or number of circuits.

Rocky Mountain Power plans to begin portions of construction in late spring/early summer of 2019 and complete the entire line in spring of 2020. However, it will not be continuous construction in your neighborhood for the entire duration. To maintain electrical service to all our customers, we will complete the rebuild in segments. Each segment of construction will take around a month or two in each neighborhood, and will be started and completed prior to starting the next segment.

Well in advance of construction, we will work directly with specific property owners about the construction schedule in their neighborhood, and to coordinate access.

Property value impacts are a common concern when a new line is built or a line is upgraded. Professional appraisers have studied this issue and have not found a significant depreciation of housing values associated with the presence of power lines; and where a transmission line is already in place, no significant change in value is expected. A recent peer-reviewed article in The Appraisal Journal concludes “…[s]urvey-based research finds adverse perceptions and general dislike for [high-voltage overhead transmission lines], but sales data reveals little to no diminution in prices. Stated preferences by market participants in this case generally do not translate into noticeable price effects as revealed in market data.”

This (peer-reviewed) article in The Appraisal Journal, (PDF) which includes thirteen years of sales data from the Salt Lake Valley,

Rocky Mountain Power designs facilities in a manner that meets or exceeds the National Electric Safety Code, as well as all state and local requirements.

The National Electric Safety Code sets the national standard for public safety relating to the installation, operation, and maintenance of electric power systems.

In regard to electromagnetic fields, Rocky Mountain Power relies on the findings of scientists and public health specialists who can best evaluate the information.

More than 1,000 studies have been conducted on this subject by scientists and public health officials during the past 25 years. The prevailing view is that the evidence does not show exposure to electromagnetic fields to be a hazard to human health.

During the public open house on July 16, 2018, Rocky Mountain Power committed to review the potential electromagnetic fields expected from the 138 kilovolt power line at maximum area loading. Preliminary findings on a similar double-circuit transmission line (138 kilovolt and 46 kilovolt) with a similar load indicate the magnetic field levels to be under 50 milligauss near the transmission line and less than 25 milligauss at a distance of 50 feet from the transmission line. The nearest portable classrooms are approximately 230 feet from the transmission line, where an expected reading would be about 2-3 milligauss.

In most cases, magnetic fields from household appliances and home wiring are stronger than magnetic fields associated with power lines and substations. Based on studies, the average magnetic field levels observed at a distance of six inches from can openers, hair dryers and electric ranges are 600 milligauss, 300 milligauss and 30 milligauss respectively.

The National Institute of Environmental Health Sciences has information about magnetic fields.

Another good information source is the National Cancer Institute website.

The rebuilt line may generate minimal sound when the weather is unusually humid or raining, although it is not usually a noticeable issue for transmission lines under 230 kilovolts, like this one.

The noise that comes from power lines is called corona. Corona is the physical manifestation of energy loss, and can transform energy into very small amounts of heat, sound and radio noise near the conductors.

Several factors, including conductor voltage, shape and diameter, and surface irregularities such as scratches, nicks, dust, or water drops can affect a conductor’s corona performance.

Rocky Mountain Power does design high-voltage transmission lines with corona mitigation, where noise generation is expected.

Rocky Mountain Power plans to upgrade the existing line in its present location within the existing easements, pursuant to the priorities set forth by community leaders in the Salt Lake Electrical Plan in 2010.

For Rocky Mountain Power to consider an alternative route, the local governmental entity or another third party would need to pay for an alternative study and any cost difference between the two designs.

Details on this requirement can be found in Utah Code, Title 54, Chapter 14; specifically, the cost requirement is found in Sections 103(8) and 201.

Rocky Mountain Power builds overhead transmission lines as standard practice due to state statute and efficiency. State Code defines standard cost as “…the cost of any overhead line constructed in accordance with the public utility’s normal practices.” (emphasis added) Utah Code, Title 54, Chapter 14, Section 103(9)(b).

When transmission lines are placed underground, the requesting party pays the additional costs associated with the request. Please refer to Utah Code, Title 54, Chapter 14. A specific study would need to be performed to determine the expected additional costs, but they are typically three (3) to seven (7) times more than an overhead line.