Environmental Assis for Orono Substation Expansion

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Xcel Energy has stated their intent to file the results of the substation noise assessment to the Project docket once the results are available. Depending on the results of the noise assessment, additional corrective steps may be required to ensure compliance with the state noise standard. Xcel Energy has also committed to performing actual sound measurements of the transformer once it is installed to confirm compliance with the state noise standard (Xcel Energy, personal communication, November 21, 2011). 5.5 Public Health and Safety Generally human health and safety issues related to transmission projects can be grouped into issues associated with construction and those associated with the operation and maintenance of the Project. As with any construction project involving heavy equipment and high-voltage electrical facilities, there are safety issues during construction. Potential health and safety impacts would be injuries related to worker falls, falling equipment and electrocution. Potential health and safety impacts associated with the operation phase of the proposed Projects include: electrocution or injury from equipment failure, injuries associated with unauthorized access to energized transmission equipment, health impacts from electric or magnetic fields associated with operation of the Projects, and stray voltage. Equipment failure and unauthorized access to transmission equipment Electric transmission lines, and their associated facilities, carry electricity at a very high voltage. This high voltage is transformed at distribution substations down to the voltage that is used by most customers at their homes. Under certain conditions, high voltage transmission lines or high voltage substation equipment may fail. These failures are most commonly a result of extreme weather or electric circuit overloading. If equipment fails, injury or death may occur as a result. Unauthorized access to transmission equipment by persons who are not trained to work with high voltage equipment can result in serious injury or death. Electric and Magnetic Fields Wherever there is electricity there are electric and magnetic fields (EMF). Electric and magnetic fields are not only created by high-voltage transmission and distribution lines, but also by home appliances, electronics, cell phones, wireless networks, fluorescent lights, and wiring configurations in homes, businesses, and schools. As a result, we are all exposed on a daily basis to a complex mix of electric and magnetic fields at many different frequencies (WHO, 2002). Electric and magnetic fields are invisible just like radio, television, and cellular phone signals, all of which are part of the electromagnetic spectrum. The frequency of transmission line EMF in the United States is 60 hertz and falls in the extremely low frequency (ELF) range of the electromagnetic spectrum (any frequency below 300 hertz). By comparison, cellular phone communications operate at frequencies almost one billion times higher than EMF resulting from electric power (Long Island Power Authority, 2005). Environmental Assessment PUC Docket E002/TL-11-223 Page 29