EMF Readings in Tollgate Crossing community Robert L. Vaessen - 22 Dec 2016

Transcription

1 EMF Readings in Tollgate Crossing community Robert L. Vaessen - 22 Dec 2016 Refer to illustration above for additional information Date: 8 Dec, 2016 / Property: Tollgate Crossing community in Aurora, Colorado located at appx coordinates of n x w / The scope of this project involved measurement of the magnitude and vector direction of 60hz power frequency magnetic fields within the Tollgate Crossing community. This report was compiled from spot measurements made on the 8th of Dec, 2016 for the residents of the community. This report is intended as an informal reference of typical EMF measurements prior to the introduction/ installation of additional 345kV power lines (planned under Xcel s Pawnee-Daniels Park project). All distance measurements are approximate, and they were made after the fact using satellite imagery using the Google Earth Pro application. Due to concerns regarding the amount of Electric and Magnetic Fields (EMF) present in our community, and the amount that may be present after a planned increase in the number of power lines in our community, Xcel agreed to participate in a manual reading of the current magnetic field levels in our community. On the 8th of Dec, 2016 (at appx 1400) - Three Xcel representatives (Robert Pearson, Ph.D. (senior project manager/tetra Tech Inc.), Derek Holscher (principal siting agent/xcel Energy), Jon Ekstrom (DEFT Communications), and one member of the community (Robert Vaessen - resident) participated in a series of manual magnetic field measurements (spot measurements/appx 30 seconds (or more) of readings per location) around the community. We met near the NE corner of the community (see location 1 in key) in order to introduce ourselves, get our bearings, discuss the measurements, the device we d be using, and who would be taking most of the readings. Here I familiarized myself with the meter/device we would be using: The Magnum 310 by Dexsil is a 3-Axis handheld device which measures magnetic field strength in three frequency bands (we used the wideband setting - RF range hz (at 3db) to measure

2 instantaneous vectored sums from the three measurement coils. The device was last calibrated (in the Dexsil lab) on the 7th of July, I saw the initialed calibration sticker on the back of the device, and the device operated perfectly during our session. The device was presented by the principal engineer (Bob Pearson), and he discussed it s capabilities and limitations. He then offered to allow me to take measurements. I held/ operated the device during some initial readings, but then allowed Bob to handle/operate the device during the remainder of our session. This allowed me to take photos during the session. We initially met and parked our vehicles near some existing power lines in our community (see location 1 below). This area afforded us a clear view of the three transmission power lines which run east west adjacent to the northern boundary of our community (see the horizontal yellow line on the provided map). Two of these transmission lines are owned/maintained by Xcel, and the third belongs to IREA (Intermountain Rural Electric Association). At this location we discussed the existing power lines, the voltage they carry, who owns/maintains them and how they will/may change in the future. After our initial meeting and brief discussions, we took a series of measurements walking south along S. Harvest Rd. to just north of the E. Layton Pl. intersection (see location 2 below). This location was selected as a representative place where we might obtain low magnetic field readings. At 582 feet south of the power lines previously mentioned (see above), this location gave us the opportunity to operate the handheld Gauss meter. After wandering around the area for a few minutes, we found a location where the meter seemed to settle down to a continuous low reading. The lowest reading we obtained was ~0.20 mg. Prior to this reading, Bob had remarked that 0.28 mg was a typical neutral reading - i.e. a reading outside the range of most EMF influence (in an urban setting). Our low reading was near the bottom limit of the device s sensitivity. This reading served as a baseline for an area that is away from obvious/primary sources of EMF. No homes nearby, major overhead power lines were 500+ feet away, and the only nearby sources of magnetic fields were buried power lines (for street lights) and an electrical service box near one of the street lights (those were across the street, appx 100 feet away). After taking these baseline low readings we headed over to the second measurement site (see location 3 below). This location (within the Tollgate Crossing community park) allowed us to occupy a position of relative distance equal to that of most homes in the community that adjoin the transmission line right-of-way (ROW). I was trying to find a spot that would put us at the same distance from the existing power lines as one of the homes in our community. From here we could take measurements that would be relatively free of magnetic field sources typically found in a home, while approximating relative distances (relative to the power lines).

3 (Illustration note: This illustration shows two homes in the vicinity of Tollgate Crossing. The home on the left is actually in Sorrel Ranch, and the home on the right is in Tollgate Crossing. The Xcel ROW shown here is located along Tollgate Crossing s southern boundary. Sorrel Ranch is a community located just south of Tollgate Crossing. This ROW runs from east to west along the boundary between the two communities) We aligned ourselves at a distance which would place us in the living room of a home. At appx 229 feet away from the power lines, we were located at one of the typical distances one might occupy if they live in a home that backs to the power lines within the Xcel ROW. The homes within Tollgate Crossing are situated at various distances from the existing power lines. In general, there are two primary classes of location: Homes that are adjacent or backing up to the power lines, and homes that are not adjacent or backing up to the ROW (where the power lines are located). Of those two categories, our measurements were meant to approximate distances that represented homes in the first category (home is adjacent to the power lines). With homes in that category, there are two distances typical to power line proximity: Power lines nearest to a home and power lines that are on the other side of the ROW. See illustration for approximate distances: Homes that are nearest to power lines are approximately ~ feet away from power lines (the home on the right). Homes that are on the other side of the ROW are approximately ~ feet (the home on the left). These measurements/distances are only meant to approximate some typical distances that home owners might encounter in a daily exposure. Your home/any home might be further from the power lines, and there might even be some homes that are closer. These measurements are linear, and the height of the power lines from the ground was not included in the measurements (so residents will

4 actually be further from the lines than indicated if angular measurements are calculated). Again, these measurements (taken from locations 3 & 4) are only estimates, but it should give you a general idea of the magnetic field exposure in vicinity to the power lines. Our device measured approximately ~1.08 mg when we were situated at a distance of approximately ~229 feet away from the power lines (see location 3 in the key). This location was meant to approximate a home that has the existing power lines on far side of the Xcel ROW. We then moved a bit closer to the power lines. To a location that would approximate the distance of a home that was located closer to the power lines. At a distance of approximately ~175 feet, we were situated near the back fence of a home on the edge of Xcel s right-of-way. At this distance, we would hope to be obtaining readings below 150 mg (the standards for maximum EMF exposure from power lines in some states, including Colorado). At this location (see location 4 in the key), our device indicated a reading of ~2.08mG. Significantly lower than the 150 mg limit set in Colorado. Most household appliances* produce significantly more magnetic fields than this (while they are operating), but a normal home s environment* (inside your home) is considerably less. Typical daily exposure in a persons home (50% of homes studied in the referenced study*) will register spot measurements of 0.6 mg or less. Depending on where you are in your home, and what appliances/devices are operating near you, the levels may be higher or lower. Our final measurements of the day were taken directly beneath the power lines (see location 5 in the key). We wanted to see where the readings topped out. What was the maximum exposure one might encounter within the ROW? There are trails running directly beneath these power lines, and the corridors create an attractive spot for people walking their dogs, out for a jog, riding their bikes or simply enjoying a walk through the community. Situated directly beneath the power lines (one of the towers is visible in the photo at left) we obtained a spot reading of ~44.8 mg. It is possible that there may be areas in the ROW where the readings are higher (areas where the power lines sag a bit. For example: At the midpoint between towers), but this measurement was meant to provide a general picture of the higher end of exposure in vicinity to the power lines. This reading of ~44.8 mg shows that the typical exposure (in the middle of the ROW) to magnetic fields is considerably lower than the level s set by Colorado s Public Utilities Commission (PUC) mg at the edge of the right-of-way. Magnetic field levels will be higher or lower throughout the year (as more power is drawn through the lines), and the levels will even change during the day (as people get ready for school/work and return home from school/work.

5 Our readings were taken on the 8th of Dec, 2016, between MST with a hand held Gauss meter. When we took our readings, there was only one set of power lines running through the ROW within Tollgate Crossing. Xcel is planning to put another set of power lines in the ROW. When they do, they project that the magnetic field levels will still fall within the PUC 150 mg limit at the edge of the ROW. Actually, under ideal conditions, some areas will actually generate lower magnetic field levels than the current levels - due to proper phase alignment and cancelling caused by the power lines being properly tuned to intentionally reduce electric and magnetic field intensities. Some homes, people, children and pets within Tollgate Crossing and surrounding affected communities (communities where Xcel will be running the new power lines) will be exposed to higher levels of EMF once/when/if the proposed second set of power lines are installed (estimated completion sometime in 2020) in the ROW. These measurements were taken to establish a firsthand accounting of existing EMF exposure. As a way of demonstrating a concrete foundation to the various studies, models and illustrations that Xcel has made available to residents, concerned citizens and various government officials. Location Key: (1) Northeast corner of Tollgate Crossing community. The east side of S. Harvest Rd., north of E. Layton Pl. Coordinates: ~ n/ w (2) Near E. Layton Pl. and S. Harvest Rd. intersection. Coordinates: ~ n/ w. Appx 582 away from power lines which run east-west along the northern boundary of community. (3) Inside the Tollgate Crossing community park, near residence at 4910 S. Duquesne St. Coordinates: ~ n/ w. Appx 229 away from power lines that run north-south along S. Degaulle St. (4) At the boundary of the community park, near the residential fence line of homes that back to the Xcel ROW (along S. Duquesne St.). Coordinates: ~ n/ w. Appx 175 from power lines that run north-south along S. Degaulle St. (5) Directly beneath the power lines that run north-south along S. Degaulle St. Coordinates: ~ n/ w. (*) Reference report prepared for the National Institute of Environmental Health Sciences (a Dept. of the National Institutes of Health). EMF Electric and magnetic fields associated with the use of electric power questions and answers: < electric_and_magnetic_fields_associated_with_the_use_of_electric_power_questions_and_answers_ english_508.pdf>. Report can be downloaded from NIEHS website: < health/topics/agents/emf/> Note: The study was published in 2002, and there have been changes in environmental sources of EMF since then. Note in particular that most homes have done away with one large source of EMF - CRTs (aka Video Display Terminals and television sets with large picture tubes). All materials contained in this report are protected by copyright and may not be used without explicit permission of the author. Photos, illustrations, and report content is copyright by Robert L. Vaessen (report author). Map imagery was taken from Apple s Maps application and is used without explicit permission. The author wishes to thank the Xcel representatives who helped conduct the spot measurements and provided information used in the report. Questions/comments regarding this report may be directed to the author: Robert L. Vaessen, <emfstudy2016@vaessen. >