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Q. How can I find more information regarding this project?
A. Click on the Contact Us button.
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Q. When will construction start?
A. Construction is anticipated to start 3rd quarter 2008.
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Q. Will the proposed line benefit me directly?
A. If you are a Duquesne Light customer in Hampton, McCandless, Pine, Richland or Ross Township, the proposed line will benefit you. The main purpose of the proposed transmission line and the upgrade to the Wildwood Substation is to provide sufficient power to meet customer needs and improve system reliability in these areas.
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Q. Will Duquesne Light extend the proposed line through Richland Township and then on to the Pine Creek Substation in the future?
A. Duquesne Light has no future plans to loop the proposed138kV transmission line from the Wildwood Substation to the Pine Creek Substation.
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Q. How many 138kV transmission lines does Duquesne Light have?
A. Duquesne Light has sixty-one 138kv transmission lines, totaling 382 circuit miles.
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Q. Are there any health effects associated with the increased voltage of the proposed transmission line?
A. Duquesne Light Company does not believe that there are any health dangers associated with the increased voltage of the proposed transmission line. Some residents, during the PUC approval process questioned whether or not electric and magnetic fields (commonly called EMFs) pose a health danger.
EMFs are present in the natural environment and wherever electricity flows. Electric transmission and distribution lines, electrical wiring in homes, video display terminals and household appliances are among the sources of these fields.
Electric fields are produced by voltage or electrical charge. The level of an electric field usually is measured in volts per meter (V/m) or kilovolts per meter (kV/m), the higher the voltage, the greater the electric field.
Magnetic fields are created by the current (flow of electricity) in a wire. They typically are measured in milligauss (mG) or microtesla (uT) (where 1 uT = 10mG). As current increases, the magnetic field level increases.
Our exposure to electric and magnetic fields depends upon where we spend time and the sources we encounter. Electric fields in the home range from 0.010kv/m away from appliances to 0.25kv/m near appliances (WHO, 1984). Electric fields from power lines are almost totally blocked by walls and roofs of buildings. In addition, the conductive nature of the human body effectively blocks exposure of the body interior to electric fields. The level of electric field that is able to develop within the body from outside sources is approximately 100 millionth (1/100,000,000) of the field level outside the body (Polk, 1996).
Questions about possible health risks from EMF exposure first arose in the 1960s and 1970s with the introduction of higher voltages for electric transmission lines in the United States. During this period, research concentrated on electric fields. Overall, studies of electric fields found no evidence of biological changes that could lead to health effects, and the emphasis of research began to shift to magnetic fields in the 1990s. (EPRI, 2005)
Magnetic field levels in the home average about 1 mG, resulting from wiring within the home, appliances, and power lines outside the home (Zaffanella, 1993). The strongest sources of magnetic fields that we encounter indoors are from electrical appliances. The strength of magnetic fields decreases as you move further away from the source. As seen in the figure below, the level of magnetic fields produced by household appliances varies greatly but diminishes rapidly with distance.
Table 1 represents magnetic field levels encountered throughout the day in a typical town.
Researchers have conducted many studies on EMF and its effects on people, animals and plants. Worldwide scientific studies and assessments by impartial and independent agencies have concluded that the electric and magnetic fields produced by power lines have not been found to be hazardous. For example, after analyzing 17 years of EMF studies by other researchers, a National Academy of Sciences panel concluded in October 1996 that there is no convincing evidence to show that exposure to EMF from power lines or household sources is harmful to humans.
More recently, results of a study of childhood leukemia, sponsored by the National Cancer Institute, were released in July 1997. This study observed no relationship between exposure to magnetic fields and level of leukemia risk. A lead author said the study was not ambiguous: it found no dangers from magnetic fields produced by power lines.
For decades, experts have debated the possible health concerns related to exposure to electrical and magnetic fields (EMFs). The report cited below represents the best scientific analysis to date on this subject and is the result of a six-year, $45 million research effort funded by Congress. You can access this report and other EMF information via the Internet at www.niehs.nih.gov/emfrapid.
Duquesne Light Company agrees with the conclusions of the NIEHS that there is no proven link between EMF and human health.
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Q. Concerning EMF, what are the expected changes in EMF levels for the proposed line? Also, will the voltage be increased on the proposed line in the future?
A. Duquesne Light has completed a study that calculated the projected change in the EMF levels between the proposed 138kV line and the existing 23kV line. The existing voltage and currents used in the calculations are present-day values, while the proposed voltage and currents are for the lines immediately after construction. The study divided the proposed 4.9-mile line into five segments based on pole and distribution circuit configuration, and the average and peak currents carried by the circuits. Peak currents occur for only a few hours on a few days of the year when power demand is the highest. For these lines, peak currents occur for about 15 hours per year, or about 0.2 percent of the time. The study shows that replacing the 23kV line with the 138kV line causes small changes in the magnetic field levels. These changes usually result in lower field levels because the 138kV line operates at a higher voltage and, therefore, requires less current to deliver the same amount of power.
The study also shows that the electric field levels will increase because of the proposed line’s higher operating voltage, but that the values are still quite low. In fact, the electric field values (even directly under the proposed line) are lower than the lowest value specified by any state which has standards or guideline that limit electric field levels at the edge of transmission line right-of-ways.
The calculated EMF values, resulting from the study, are shown in separate tables, one for each line segment. To view a table, click on the link below, and then click on the highlighted rectangle on the map closest to your location of interest.
Duquesne Light has no plans to increase the voltage of the proposed 138kV transmission line in the future.
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Q. What about issues with corona, such as noise and radio and TV interference?
A. Corona discharge on high-voltage transmission lines is the ionization of air near the surface of the conductors where electric field magnitudes are largest. Corona occurs at conductor surface irregularities, or most commonly, water droplets. Because water causes corona, corona effects are generally strongest during rain, snow, and fog when water is present on the conductors.
Each corona discharge releases small amounts of heat, light, sound pressure, and electromagnetic energies. The discharges combine to produce audible noise and electromagnetic noise (in some cases, a faint glow is visible at night during wet weather). At sufficiently high levels, the electromagnetic noise may interfere with radio and TV broadcast signals.
Corona effects increase with higher line voltages due to the increase in electric field magnitudes at the conductor surfaces. However, corona is typically not a significant design issue at line voltages of 230kv and lower. Thus, corona, and the associated noise and radio and TV interference, is not expected to be an issue for the proposed 138kv transmission line. In fact, Duquesne Light has years of experience operating 138kv lines in residential areas without problems caused by corona.
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Q. Can Duquesne Light provide web sites where I can obtain information regarding Electronic and Magnetic Fields (EMF).
A. The following links provide the most up to date answers on research for EMF.