Frequently asked questions about the Price Road Corridor 230-kV transmission project

Choose any link to get answers to your questions about the Price Road Corridor.

Project details

SRP is planning to construct new electrical infrastructure to enhance reliability for current customers and support new and expanding businesses in Chandler's Price Road Corridor. The corridor is a thriving employment center and innovation hub that will provide new jobs during the next two decades.

SRP must be prepared to accommodate higher demand for power that comes with the eventual build-out of this area. With recent renewed interest for businesses to locate in the Price Road Corridor, the 69-kV system currently providing power to the corridor must be supported by our higher voltage 230-kV system. SRP anticipates the additional growth will require increased energy-delivery capacity.

The project was submitted to the Arizona Corporation Commission in SRP's January 2012 Ten Year Plan.

Electric system upgrades along the Price Road Corridor will enhance the reputation of the area as a great place to work, live and play. The community benefits from a strong, diverse economy that provides high-paying jobs and a strong tax base. System upgrades will increase electric service reliability to current residential, commercial and industrial customers in the area and ensure that we can meet future demand caused by growth.

A typical 230-kV pole is 120–150 feet tall, depending on final span lengths and whether the pole also holds 69-kV circuits.

No, SRP is a community-based, nonprofit utility. We do not have stockholders or pay dividends. Earnings, called "net revenues," are reinvested into power plants, power lines and other facilities to serve our customers and keep our prices low.

A typical substation serves about a 40-square-mile area. However, an industrial area such as the Price Road Corridor requires more power than a primarily residential area. As a result, a substation that provides power to several large businesses may serve a smaller geographic area.

SRP calculates electric forecast demand using data from a variety of sources including existing customer power usage, anticipated customer expansion, potential growth on undeveloped land, inquiries from potential developers, and zoning and planned area development. For example, the City of Chandler Economic Development Division shares economic development information with SRP. SRP combines all this information with SRP electric forecast information to determine future need for each localized area (69-kV distribution station areas). SRP then groups the information within larger energy power delivery areas (230-kV receiving station areas).


Public process

Since 2012, SRP has conducted an extensive public process with multiple rounds of public open house meetings. The open houses allowed the public to review informational displays, discuss the project with SRP team members and provide valuable feedback. In addition, SRP extended invitations to present project information and address questions to all Homeowner Associations adjacent route segments and provided presentations to area Associations and Civic Organizations.

Input provided by stakeholders, property owners, residents, businesses, agencies and interested organizations was an important factor in the siting study. The process was specifically designed to evaluate route options based on specific, electric-industry-supported criteria that allowed for an objective analysis. Public input helped to identify community sensitivity toward each of the criteria and where facilities fit best within the community (referred to as siting opportunities). Any comments submitted on our website were considered in the permitting process for this project. SRP seriously considered all the comments submitted concerning this project. However, the comments received were not considered a popular vote.

No, the project team is evaluating route alternatives identified in an earlier public process to connect the Knox substation, located north of Pecos Road west of 56th Street, with the new RS-27 230-kV substation.

SRP will hold public open houses to gather comments on route considerations within the project's reduced scope and to review possible route alternatives to connect the Knox substation, located north of Pecos Road, west of 56th Street, with the new RS-27 230-kV substation site at the intersection of Germann and Price Roads.

Following the public process, SRP will apply for a Certificate of Environmental Compatibility (CEC) with the Arizona Corporation Commission. Hearings will be held by the Arizona Power Plant and Transmission Line Siting Committee. If the committee grants the CEC, then the final decision to confirm the CEC will be decided at an open meeting of the Arizona Corporation Commission.

SRP anticipates that the project could come before the commission for approval this summer.

Visit our Next Steps and Schedule page for a list of upcoming meetings.


Siting considerations

SRP applies four specific considerations to each route possibility:

  1. Ability to obtain land rights/rights of way – Can SRP acquire an easement wide enough to physically accommodate the new transmission lines with minimal impact to existing homes and businesses?
  2. Constructability – Can SRP construct new poles along this alignment? Are there obstacles above or below the ground?
  3. Maintenance access – Can SRP maintenance crews get the necessary equipment (cranes, trucks, etc.) to the poles and wires to perform required maintenance? Would the work require SRP to shut down a lane or more of traffic?
  4. Cost – What are the total costs for rights of way, construction and maintenance?

The project team needs to address these considerations with each possible route.

No, the project design will comply with federal aviation standards, and we will work with local airports to avoid safety issues.

SRP is not considering burying 230-kV power lines for aesthetic reasons. At approximately 11 times the cost of overhead construction, undergrounding is cost prohibitive. Asking all SRP customers to share the costs of undergrounding to benefit one area is not equitable. However, undergrounding is planned near Stellar Airpark for safety reasons.

To evaluate the reasonableness of our original cost estimate for 230-kV underground, SRP recently obtained updated information from three cable/accessory manufacturers (for cable, splices and terminations), two concrete firms (backfill material) and two civil construction contractors (open trench and boring under intersections). We also reviewed prints of the Chandler water project along Ocotillo Road to determine the location of other underground utilities we would have to avoid. We concluded:

  • Cable prices are a little lower than we had assumed because of competition among new U.S. factories
  • The degree of difficulty in the civil construction is a little higher than we had assumed
  • Our overall assessment of the total project cost did not change significantly

As a result of this new assessment, SRP has determined that the cost of undergrounding remains at 11 times the cost of overhead construction. The cost of overhead construction is still estimated at $900,000 per mile and underground is estimated at $10 million per circuit mile.

The Price Road Corridor 230-kV project is needed to serve a localized area around Price Road and improve the reliability of SRP's 230-kV "backbone" system in the Valley.


Electric and magnetic fields

Electric and magnetic fields (EMF) are part of our everyday lives. They occur wherever there is a flow of electricity and everyone is exposed to EMF in modern society. All electric devices and lines – appliances, computers, wiring in homes and offices, powerlines – produce EMF. The earth also produces a strong natural static magnetic field.

Electric fields result from electric voltage. These fields are measured in kilovolts per meter (kV/m).

Magnetic fields result from the flow of electric current. The fields are measured in milliGauss (mG).

Exposure to EMF in a home is generally from electric appliances and house wiring. Some typical levels are listed below. Field levels at normal operating distances are shown in bold.

Electrical appliance mG at 1 inch mG at 1 foot mG at 39 inches
Hair dryer 60 – 20,000 0.1 – 70 0.1 – 0.3
Electric shaver 150 – 15,000 0.8 – 90 0.1 – 0.3
Vacuum cleaner 2,000 – 8,000 20 – 200 1.3 – 20
Microwave oven 730 – 2,000 40 – 80 2.5 – 6
Iron 80 – 300 1.2 – 3 0.1 – 0.3
Television 25 – 500 0.4 – 20 0.1 – 1.5

Source: World Health Organization

Please note: Magnetic field levels decrease rapidly as you move away from the source. Field levels from similar devices can vary a lot based on the brand and design of the device.

Electric transmission lines produce magnetic fields. The strength of a magnetic field from a transmission line decreases rapidly with increasing distance from the source. Below are typical ranges of magnetic fields calculated at 1 meter above the ground underneath the wires and at other perpendicular distances from a 230-kV transmission line:

Line configuration Range of magnetic fields (mG) at lateral distance of:
  0 feet 50 feet 250 feet
230-kV line with two underbuilt 69-kV circuits 10 – 20 5 – 10 0.5 – 1
230-kV line with no 69-kV underbuild 30 – 60 12 – 25 0.7 – 1.4

The major research on health effects of low frequency (60-Hz) EMF has been performed in the following areas:

  • Epidemiological studies attempt to establish patterns, links or association between environmental agents and diseases in human populations, such as cancer or leukemia.
  • Animal studies have been performed on animals over several generations at exposures that are thousands of times higher than the EMF in a typical residential setting.
  • Biological studies look for EMF responses on individual cells or DNA.
  • Clinical studies have been performed on human volunteers in residential or work environments.

The overall scientific consensus about EMF and health effects is summarized by information currently posted on the World Health Organization (WHO) website. "Based on a recent in-depth review of the scientific literature, the WHO concluded that current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields."

Several thousand scientific papers have been published and over two dozen expert panels have reviewed this research. For most diseases, the epidemiology has been inconclusive and inconsistent, although some childhood leukemia studies have found an increased risk with magnetic field exposures. Epidemiological studies do not provide a conclusive cause and effect between EMF exposure and disease, and the animal, biological and clinical studies which have been done do not support a hypothesis that EMFs are harmful. Additionally, no plausible bio-mechanism is known by which 60 Hz magnetic fields would be harmful.

The overall scientific consensus about EMF and health is summarized by information currently posted on the WHO website. "Based on a recent in-depth review of the scientific literature, the WHO concluded that current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields."

Neither the U.S. government nor the State of Arizona has established exposure standards for public exposure to power frequency EMF.

Two international organizations, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute of Electrical and Electronic Engineers (IEEE), have developed exposure guidelines:

Established EMF Exposure Guidelines for Power Frequency Magnetic Fields
International Commission on Non-Ionizing Radiation Protection 2,000 mG¹
Institute of Electrical and Electronic Engineers 9,040 mG

There are many different types of medical implants and many different manufacturers. People with implanted devices should follow the manufacturer's recommendations for their particular device and may want to consult with their physician about potential sources of electromagnetic interference (EMI). One leading manufacturer (St. Jude Medical) notes that their current generation of implanted devices are designed to meet electromagnetic compatibility requirements of American National Standard ANSI/AAMI PC69-2007 and European Standards EN 45502-2-1 and prEN 45502-2-2. If so, they are designed to avoid EMI from stronger electric and magnetic fields than will be produced by the Price Road Corridor 230-kV lines.

Source: document is a .pdf


Property questions

Soon after SRP receives a CEC for the line, we will design the line within the certified corridor. At that time, SRP engineers will determine if an easement is needed across your property. If an easement is needed, SRP will hire an independent appraiser to value your property and the easement. You, as the property owner, will receive a copy of the appraisal report with an offer letter from SRP to purchase the easement.

We don't know at this time. There are many variables to consider in the valuation process. Since each home is different, an appraiser will have to take into account the home itself (e.g., square footage, age, condition, etc.) along with its characteristics (e.g., carport, two-or three-car garage, pool or no pool, lot size, etc.). The appraiser also will consider current market conditions of the neighborhood and its unique amenities (e.g., quality of schools, available retail shopping, restaurants, parks, other recreational amenities, ease of access via freeways and local streets, etc.).

Generally, transmission lines are not considered to be a material factor in the determination of property values. Given the number of variables to evaluate in the appraisal process, it would be inaccurate and misleading to give any specific response regarding the value of any specific property without an appraisal. If the appraiser determines that the presence of the easement on the parcel reduces the parcel's value, SRP will compensate the owner for this reduction in value. SRP compensates property owners only if an easement is needed across a specific parcel.


Comments and information

If you have questions for SRP, please use our online comment form or call the toll-free line at (602) 236-2872.