Tel: (517) 788-3000
Fax:
(517) 788-3003
P.O. Box 1124, Jackson, Michigan 49204-1124 Email: jhguidinger@cai-engr.com
March 21, 2001
Honorable Frank B. Tiffany
City of Sunfish Lake
369 Salem Church Road
Sunfish Lake, MN 55118
Dear Mayor Tiffany:
At your request, Dave Shafer and I have reviewed the report of MSB Energy Associates (MSB), a consultant for Roger Conant. We have the following comments, which follow the headings in the MSB review.
Introduction
MSB expresses “serious concerns” as to whether Commonwealth Associates, Inc. (CAI) provided an independent review because “CAI was Xcel’s choice for this review” and because “CAI apparently has a contract with Xcel to work on the design of the proposed double circuiting.” Our response is as follows:
1. We will state simply that our review was in fact an independent study following the scope of work defined by the Steering Committee. The study team at CAI worked very hard on the report over many months. The review is independent in that we used our own methods and our own computer programs, and we provided information from our engineering and environmental experience in working with many transmission line clients over 30 plus years. At no time was any consideration given as to whether or not our findings would result in additional engineering work for CAI.
2. We disclosed our relationship with Xcel prior to being selected to do the review and at each of the three previous public meetings of the Steering Committee. Our civil design engineers have been working with and currently do work with Xcel. However, our planning and environmental staff has not and does not presently work with Xcel.
3. We understand that CAI was one of 5 to 10 organizations invited to bid on the review. CAI and one other firm were selected by the Steering Committee to travel to Mendota Heights for a pre-selection interview. The final selection of CAI was made by the Steering Committee, not by Xcel.
4. We have primarily focused our review on providing data and facts to the Steering Committee rather than giving opinions and conclusions. However, when asked to express opinions, we have done so. We have not recommended any option over another.
5. We are registered professional engineers and we hold to the Code of Ethics as published by the National Society of Professional Engineers. The Fundamental Canons of that code of ethics include the following:
a. Hold paramount the safety, health and welfare of the public.
b. Perform services only in areas of competence.
c. Issue public statements only in an objective and truthful manner.
6. We understand that our report will be reviewed by people with immediate and direct knowledge of transmission lines, the Xcel 115 kV system, and the specific Red Rock-Wilson 115 kV transmission line. Any attempt to slant the information in a self-serving fashion would be instantly recognized by the reviewers. No engineering company could stay in business long by slanting studies. The “Commonwealth” name of the present Commonwealth Associates, Inc., can be traced back through predecessor companies to the 1890's.
7. Xcel commonly bids engineering work out to many engineering companies like CAI. Xcel has the in-house capability to do the work itself. Xcel may also decide to postpone the work indefinitely. Therefore, there is no certainty that CAI would be chosen to perform any engineering work on this line.
8. All options defined in this report will require engineering work. Other conceivable options will also require engineering work. Therefore, the possibility of new work is not option-specific.
9. This year, CAI expects to do about $12 million in engineering work. The value of potential new work on this line possibly arising from our review would be tiny, probably less than 1 percent of our total revenues.
10. It is not uncommon for CAI to make recommendations that result in less work for CAI when such a recommendation meets the best needs of the client. For example, a New Jersey IPP developer working on its first new power plant in Ohio asked us in February to assist in the interconnection facilities for the plant. The site required 8 miles of 345 kV transmission line to interconnect with an existing 345 kV line. We were asked to acquire the right-of-way, prepare detailed environmental permit applications, and design the transmission line and interconnection switchyard. However, after we studied the project, we advised the client that right-of-way and environmental problems would likely be insurmountable. We recommended that they move the plant site to the interconnection point and build the necessary gas fuel and water lines to that point. Since we do not design power plants or gas or water lines, this recommendation resulted in the loss of considerable environmental and design work. However, it served the needs of the client much better, and the client was very appreciative of our advice.
11. As we have stated at each of the three previous public Steering Committee meetings, CAI is extremely busy at present. Many staff members are working overtime after hours and on weekends, and some sections of the company are turning work down at the present. Our company’s future does not depend on completing the engineering work for the Red Rock-Wilson project.
Double-Contingency
Planning Criteria
MSB questions the use of double-contingency criteria for planning transmission. We respond as follows:
1. We reviewed planning documents provided by Xcel that covered the Minneapolis area. The earliest document was for 1993 and the latest document was for 2000. In all of these documents, Xcel consistently stated that the Twin Cities metro area transmission system is planned and designed to withstand double-contingency operating conditions. We state that as a fact.
2. We were asked if other utilities also use double-contingency criteria, and we answered, based on our experience, that we know of other utilities that use double-contingency criteria. Our most recent experience is with the AEP bulk power system, which is based on double-contingency criteria.
3. In our opinion, the use of double-contingency planning criteria for a major metropolitan area is reasonable and prudent given the economic consequences of even a short-term outage in industrial and commercial areas.
Alternative Routes
MSB questions why we limited the review of alternative routes.
Our instructions at the beginning of the project were to review alternative routes for the second circuit between the Red Rock, Rogers Lake, Bloomington, and Wilson Substations. These substations are only a few miles apart (Report page 2-1). To avoid excessive circuitry, these short distances would tend to limit potential alternative routes to those in the general area of the existing route. New routes to each substation from sources of power at greater distances from, say, the north or south were studied as system alternatives Options C, D, and E. Based on our experience, we believe that the impacts of other longer new routes would be obviously far greater than the impacts of Routes A and B or other routes that could be assembled from the links identified in the report.
Line Design Considerations
MSB states that the 795 kcmil conductor is unusually large. We find that:
1. The 795 kcmil conductor is commonly used today for 115 kV transmission lines by utilities throughout the United States. In fact, 954 kcmil, 1033 kcmil and even larger conductors are also being used today for 115 kV transmission lines.
2. The 795 kcmil conductor is currently used on the existing line between Red Rock and Rogers Lake, about 44 percent of the existing line length.
MSB states that the line could be upgraded to a higher voltage in the future by simply replacing substation transformers. Assuming that MSB is referring to 230 kV (CAI understands that 138 kV and 161 kV are not used by Xcel), we respond as follows:
1. The conceptual structures have a minimum phase spacing of 12 feet and a minimum phase to grounded member spacing of 9' 3" (Figure 3-2). For 230 kV, these spacings would have to be on the order of 15 to 16 feet and about 10 to 11 feet, respectively.
2. The longer 230 kV insulator strings would require taller structures to maintain the minimal clearance above the ground.
Therefore, it would be necessary to replace all the structures to increase the voltage from 115 to 230 kV, as well as the transformers at numerous substations. This would require regulatory review.
Electric And Magnetic Fields
MSB states, “Neighbors of the existing Red Rock - Wilson transmission line are concerned with the health impacts of electric and magnetic fields (EMF). The CAI Report does nothing to assuage that concern. Rather, it suggests that the line’s neighbors have reason to be concerned.” We reply as follows:
1. We were careful from the very beginning of the project to state that comments on the health issues are beyond our training and expertise as professional engineers and that it would be inappropriate for us to include such in our engineering report. This was accepted by the Steering Committee.
2. We have proposed a qualified individual, Dr. Peter Valberg, to address the human health issues separate from the engineering considerations. From the beginning of the review, the Steering Committee agreed that his input would be in the form of verbal responses to questions from the public at the final Steering Committee meeting.
3. While we cannot render a professional opinion on the human health effects of EMF, we certainly are responsible for tracking any regulations that impact the engineering design of transmission lines. The State of Minnesota does not have a standard or guideline with regard to magnetic fields but does regulate electric fields to a maximum of 8 kV/m within the right-of-way. These issues were addressed at length in earlier regulatory filings provided by Xcel and were never questioned in our earlier three Steering Committee meetings.
4. The EMF health issues have been extensively studied over the past 30 years and have been carefully reviewed by the scientific community, by engineering standards boards, as well as by federal and state regulatory agencies. These agencies are the watchdogs of the industry with regard to establishing standards and regulations. We believe it would be inappropriate for our engineering report to make claims as to the health impacts or to establish EMF limits.
MSB states: “The EMF field levels calculated by CAI for the existing line are extraordinarily high for a transmission line. And the calculations underestimate the fields affecting many of the line’s neighbors.” We reply as follows:
1. We were not making a value judgment as to whether the EMF fields were high or low but were simply providing the calculations as requested by the Steering Committee.
2. When discussing EMF levels, we need to distinguish between electric and magnetic fields. The electric field is a function of voltage and similar for all 115 kV lines. Therefore, we could not characterize the electric field as extraordinarily high. The magnetic field level is a function of loading and, again, for any 115 kV line that has a similar loading, we would expect to see similar levels of magnetic field. Therefore, we could not characterize the magnetic field as extraordinarily high.
3. Tables 3-4 through 3-8 provide the results of calculations for magnetic field for loadings from 100 amps to 1600 amps and for distances from 0 (directly underneath the line) to 500 feet from the line. These numbers are summarized in Tables 3-3 and 3-4 out to 100 feet, and additional EMF detail is shown in Appendix B. Certainly, these calculations provide estimates of magnetic field levels well beyond expected peak loadings of the line (see Table 3-1). We don’t see how we could have underestimated exposure.
4. It is our opinion that interpretation of these numbers as the typical exposure to the neighbors overstates the exposure for the following reasons:
a. The line loadings and, hence, magnetic fields will vary throughout the day and throughout the seasons. What is calculated is the magnetic field for maximum expected loadings. Most of the time the loading and magnetic field will be less.
b. The magnetic field is a function of distance from the conductor. This will vary depending upon the location of the home versus the support structures, the distance from the right-of-way and the rise or fall of the ground away from the line. Hence, the distance to the center of the residence that is used for calculating typical exposure will be greater than the edge of right-of-way distance that is used as the reference point for calculating EMF.
MSB states, “The CAI calculations use the average height of the line above ground. A transmission line sags from tower to low point and then goes back up to the next tower. Residences at the low point of the sag will have greater EMF impacts than are calculated for the average height.” We respond as follows:
1. EMF calculations were provided for 25-, 30-, and 40-foot conductor heights. Refer to Appendix B. We believe these numbers capture the low point of the conductor sag. The calculations make many simplifying assumptions, such as level ground, infinitely long parallel conductors at the conductor height, and balanced electrical loading in all three phases. The conductor sag is also a function of conductor temperature. In the wintertime the cold ambient air will result in less conductor sag (higher conductors) than in the hot summertime. We provided base numbers at 30-foot conductor height to be consistent with previously published reports. We believe we have provided enough information in the report to estimate magnetic field levels for any reasonable circuit loading and any reasonable conductor height.
MSB states, “A number of residents are closer to the line than the values used by CAI. Their residences will receive higher levels of EMF.”
1. There are no residences closer to the line for which EMF values are not given. We have calculated the values for zero feet from the centerline at 3 feet and 12 feet above the ground. How could any residence be closer?
MSB states, “The CAI calculations focus on a height of three feet above the ground. Residences close to the line will have heights much greater than three feet. The three-foot calculations are of limited value.” We respond as follows:
1. The three-foot height above ground (actually it is one meter) is the accepted industry standard for EMF calculations and measurements. Refer to IEEE Std. 644-1994.
2. We provided calculations at 12 feet above ground at the request of the Steering Committee in the first public meeting. However, we suggest that these calculated numbers be used with great care since they do not conform to industry standards.
MSB states, “The CAI Report shows magnetic fields 20 feet from the line at a height of 12 feet of 166 milliGauss (mG). This is a very high level.” We respond as follows:
1. We would not characterize this as a high level. Typical EMF levels found around home appliances are in this range. Refer to Questions and Answers About EMF, Electric and Magnetic Fields Associated with the Use of Electric Power, National Institute of Environmental Health Science and U.S. Department of Energy, January 1995.
2. Only two organizations have developed guidelines for human exposure to magnetic fields. The American Conference of Governmental Industrial Hygienists (ACGIH) 1994 established that occupational exposure should not exceed 10,000 mG and, for workers with cardiac pacemakers, the field should not exceed 1,000 mG. The International Commission on Non-Ionizing Radiation Protection (IRPA/INIRC) established guidelines for general public exposure for up to 24 hours per day of 1,000 mG and for a few hours per day, 10,000 mG.
Impacts
Of High Levels Of EMF
MSB, with reference to “Impacts of High Levels of EMF,” mentions “modest levels of EMF” and “high levels of EMF.” We are not familiar with how modest and high are defined and where these are being used with regard to regulation of transmission line EMF levels.
MSB states, “ … Public Service Commissions like the Wisconsin PSC have ordered utilities to design facilities to minimize EMF levels so as to minimize the possibility of people being harmed.” We respond that the proposed double-circuit line reduces EMF exposure to the neighbors. The text and Figure 3-2 in our report show clearly that the conceptual design of the proposed structure includes reverse phasing and vertical orientation of the conductors, which will reduce the intensity of the magnetic field.
What Is The Relevance Of The Level Of EMF From The Current Line?
MSB states, “ … we cannot tell from the CAI Report just what the EMF field may be from the double circuited line, since the report does not calculate the fields for the case where a residence is close to the line (for example, 20 feet), at a height of 12-15 feet, with high currents flowing through the line (for example, 800 amps on each circuit).” We respond as follows:
1. The tables and curves in Appendix B show calculated EMF values for a residence at 20 feet from the line for a 12-foot hight above the ground for five cases.
2. A good comparison of the single-circuit design versus double-circuit can be obtained by comparing Table 3-4 with Table 3-5. For example, at 800 amps and 25 feet from the centerline the magnetic field for the single circuit is 86.7 mG, compared with 42.0 mG for the double circuit and 800 amps in each circuit. Thus, the double-circuit line reduces magnetic field by more than 50 percent.
MSB states, “An alternative which should have been analyzed by CAI would have included the removal of the current line.” We respond as follows:
1. We are not sure of the context of this question. It is under the heading “What is the Relevance of the Level of EMF from the Current Line.” If the question is, what is the EMF if we remove the existing line, of course, the answer is zero. If we build a comparable line somewhere else, the EMF is the same as we have calculated only moved to the other location. The numbers of residences impacted by the alternative routes are provided in Tables 6-2 and 6-3.
2. If the context of the question refers to the electrical system planning, removing the existing line and replacing it with either a single-circuit or double-circuit line will not change the systems analysis significantly provided that the circuit arrangements are maintained as shown on Figures 2-2 through 2-6.
Miscellaneous Issues
Photo Simulations. We agree that the replacement structures will be more noticeable.
MnDOT. MSB said, “It seemed to us, reading the meeting minutes, that the Minnesota DOT was more open to the idea of corridor sharing than CAI suggests in its summary.” We have discussed this at length in the three previous public meetings and stand by our statements in our report.
Property Values. The presence of transmission lines may have a negative influence on property values. Several negative numbers are shown in the sales price studies quoted in our report and in the sales comparisons performed by Colliers Towle in Table 7-2.
This concludes our review of comments by MSB Energy Associates.
Yours truly, Yours truly,
John Guidinger David A Shafer, P.E.
Environmental Coordinator Electrical Systems Engineer