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Record of Decision and Floodplain Statement of Findings; Imperial-Mexicali 230-kV Transmission Lines

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Office of Electricity and Energy Assurance,[1] U.S. Department of Energy (DOE).


Record of Decision (ROD) and Floodplain Statement of Findings.


DOE announces its decision to implement the Proposed Action alternative, identified as the preferred alternative, in the “Final Environmental Impact Statement for the Imperial-Mexicali 230-kV Transmission Lines” (DOE/EIS-0365). That alternative is to grant a Presidential permit to both Baja California Power, Inc. (BCP; hereinafter referred to as Intergen [2] ) and Sempra Energy Resources (hereinafter referred to as Sempra [3] ) for each to construct, operate, maintain, and connect a double-circuit, 230,000-volt (230-kV) electric transmission line that crosses the U.S.-Mexico border in the vicinity of Calexico, California, and connects to the associated natural gas-fired electric power plant located near Mexicali, Mexico. The permits will authorize the transmission lines to connect to the respective power plants as those plants are presently designed.

In reaching this decision, DOE considered the potential environmental impacts in the U.S. from constructing and operating the two transmission lines and from the related action of operating the two associated Mexico power plants. DOE also considered the continuing need for additional electrical supplies in the region, the low potential environmental impacts, the lack of adverse impacts to the reliability of the U.S. electric power supply system, the practicality or the availability of the alternatives, and public comments provided during the preparation of the EIS.

This ROD and Floodplain Statement of Findings have been prepared in accordance with the regulations of the Council on Environmental Quality (40 CFR Parts 1500-1508) for implementing the National Environmental Policy Act (NEPA), DOE's NEPA Implementing Procedures (10 CFR Part 1021), and Start Printed Page 21190DOE's Compliance with Floodplain and Wetland Environmental Review Requirements (10 CFR Part 1022).


The Final EIS and this ROD are available on the DOE NEPA Web site at​nepa/​documents.html and on the project Web site at​bajatermoeis. Copies of the Final EIS and this ROD may be requested by toll-free telephone at 866-542-5903, or by contacting Ellen Russell at the Office of Electricity and Energy Assurance, TD-1, U.S. Department of Energy, 1000 Independence Avenue, SW., Washington, DC 20585, or 202-586-9624, or by electronic mail at

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For further information on the Imperial-Mexicali 230-kV Transmission Lines EIS, contact Ellen Russell as indicated in the ADDRESSES section above. For general information on the DOE NEPA process, contact Carol Borgstrom, Director, Office of NEPA Policy and Compliance, EH-42, at U.S. Department of Energy, 1000 Independence Avenue, SW., Washington, DC 20585, or 202-586-4600, or leave a message at 800-472-2756.

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In the EIS DOE considers the environmental impacts associated with granting Presidential permits to Sempra and Intergen that would authorize the construction, operation, maintenance, and connection of the proposed double-circuit 230-kV electric transmission lines that would cross the U.S.-Mexico border in the vicinity of Calexico, California. Because the proposed routes for these lines cross Federal lands managed by the U.S. Department of the Interior's Bureau of Land Management (BLM), BLM worked on the EIS with DOE as a cooperating agency. BLM will issue a separate ROD, also based upon the EIS, in which it will announce its decision whether to grant rights-of-way (ROWs) for the proposed transmission lines.


Executive Order (E.O.) 10485 (September 9, 1953), as amended by E.O. 12038 (February 7, 1978), requires that DOE issue a Presidential permit before an electric transmission facility may be constructed, operated, maintained, or connected at the U.S. international border. DOE may issue a permit if it determines that the permit is in the public interest and after obtaining favorable recommendations from the U.S. Departments of State and Defense. In determining whether issuance of a permit for a proposed action is in the public interest, DOE considers the environmental impacts of the proposed project pursuant to NEPA, the project's impact on electric reliability by ascertaining whether the proposed project would adversely affect the operation of the U.S. electric power supply system under normal and contingency conditions, and any other factors that DOE may also consider relevant to the public interest.

On February 27, 2001, Intergen applied to DOE for a Presidential permit to construct a double-circuit 230-kV electric transmission line across the U.S.-Mexico border in the vicinity of Calexico, California. In a separate but similar application filed with DOE on March 7, 2001, Sempra applied to DOE for a Presidential permit also proposing to construct a double-circuit 230-kV transmission line across the U.S.-Mexico border within the same existing utility corridor as the Intergen line.

Each applicant sought to construct a line parallel to an existing San Diego Gas & Electric Company (SDG&E) transmission line and both would connect to the existing SDG&E Imperial Valley (IV) Substation located approximately 6 miles (10 km) north of the U.S.-Mexico border in Imperial County, California. The centerline of the Intergen line would lie 120 feet (37 m) east of the centerline of the existing SDG&E line, and the Sempra line would lie 120 feet (37 m) east of the centerline of the Intergen line, each centered in adjacent 120-foot (37 m) wide ROWs. Because both proposed lines were intended to cross lands managed by BLM, both Intergen and Sempra applied to BLM for ROW grants.

Previous NEPA Review and Litigation

Due to the similarities of these proposals, DOE and BLM decided to cooperate on the environmental review and to consider both proposals in a single environmental document. DOE and BLM originally determined that the appropriate level of NEPA review for the Presidential permit applications and the ROW grants was an environmental assessment (EA). An EA is prepared to determine whether a proposed action would have a significant impact on the human environment. If the EA shows that it would, the agency would then prepare an EIS; if not, the agency would issue a finding of no significant impact (FONSI).

DOE and BLM issued their EA in December 2001 (DOE/EA-1391), and on December 5, 2001, DOE issued a FONSI together with the requested permits. Similarly, on December 19, 2001, BLM issued two FONSIs, and the next day granted the ROWs. Following these decisions, Intergen and Sempra constructed the transmission lines and began commercial operations, transmitting electricity to the U.S. from their respective power plants in Mexico.

On March 19, 2002, the Border Power Plant Working Group (hereinafter referred to as Border Power) sued DOE and BLM in the U.S. District Court for the Southern District of California (Case No. 02-CV-513-IEG (POR)), alleging violations of NEPA and the Administrative Procedure Act (APA). Border Power sought to have the EA, DOE's and BLM's FONSIs, the Presidential permits, and the ROW grants determined to be illegal and requested an injunction forbidding the use of the transmission lines. After briefings and oral arguments in which Intergen and Sempra participated as intervenors, the District Court issued two orders. In its May 2, 2003, order, the court held that the EA and the FONSIs did not comply with NEPA and the APA. On July 8, 2003, after a hearing to determine an appropriate remedy, the court sent the matter back to DOE and BLM for additional NEPA review. At the same time, the court declined to immediately enjoin operation of the transmission lines; instead, it deferred setting aside the Presidential permits and the FONSIs until July 1, 2004, or until such time as superseding NEPA documents were issued, whichever was earlier. Thus, the transmission lines could continue to provide electricity to California while DOE and BLM conducted additional NEPA review. The court has since extended the July deadline, and the lines continue to operate.

In light of the concerns raised by the court and to increase opportunities for public and stakeholder participation in the environmental review process, DOE and BLM decided to prepare an EIS. In its July 8, 2003, order, the court expressly prohibited DOE and BLM from considering in the additional NEPA review or in their final decisions the fact that the transmission lines had already been built and were operating. The court also prohibited the Federal agencies from relying upon the court's analyses of environmental impacts of the proposed actions. DOE and BLM interpreted this language as requiring that they conduct their NEPA review from a fresh slate. Thus, the discussion of the transmission lines and the environmental analysis is presented in the EIS as if the lines do not exist.

In contrast, DOE and BLM interpreted the court's ruling to allow them to consider the associated power plants in Mexico as they have been built. Assuming otherwise would limit DOE's Start Printed Page 21191and BLM's ability to perform an analysis of sufficient detail to effectively evaluate the Alternative Technologies alternative, which would be implemented in the context of a retrofit of alternative technologies to the existing plants. The agencies also believe that the focus of the court's decision was directed to the decision before the Federal agencies, that is, whether to permit the transmission lines themselves. This interpretation allowed the agencies to perform a more realistic evaluation of the Alternative Technologies alternative, that is, the retrofit of existing plants, than could have been performed with respect to hypothetical plants.

On October 30, 2003, DOE published a notice of intent to prepare an EIS (68 FR 61796). On May 14, 2004, the U.S. Environmental Protection Agency (EPA) published a notice of the availability of the Draft EIS (69 FR 26817), thereby beginning the public comment period on it. During the comment period, DOE and BLM received over 4,800 comment submissions in the form of mass e-mails and facsimiles, letters, and oral statements at public hearings. In preparing the Final EIS, DOE and BLM considered and responded to all of the comments received. EPA announced the availability of the Final EIS on December 17, 2004 (69 FR 75535).

The Proposed Projects

Intergen's transmission line would connect SDG&E's IV substation with the La Rosita Power Complex (LRPC), which consists of two separate generating units: the EBC unit and the EAX unit. The EBC unit consists of one 160-megawatt (MW) gas turbine operated in combined-cycle mode with one 150-MW steam turbine, for a total electrical capacity of 310 MW. To reduce air emissions of nitrogen oxides (NOX), Intergen designed and built the EBC gas turbine with low-NOX burners and Selective Catalytic Reduction (SCR) technology. This unit was built to export its full electrical output to the U.S. and, as presently configured, could export only over Intergen's proposed international transmission line.

The second unit at LRPC, the EAX unit, consists of three 160-MW gas turbines (EAX-A, EAX-B, and EAX-C) operating in combined-cycle mode with one 270-MW steam turbine, for a total electrical capacity of 750 MW. Intergen originally equipped these turbines with low-NOX burners and later decided to add SCR to further reduce NOX emissions. SCR was added to the EAX-C turbine in March 2004. Installation of SCR on the EAX-B turbine has been completed and the turbine was placed back in operation on March 31, 2005. Installation of SCR on the EAX-A turbine also has been completed and the turbine returned to operation on or about April 10, 2005.

The electrical output of the EAX-C gas turbine (160 MW) is designated for export to the U.S. but could be connected either to the proposed new international transmission line or to the existing (previously permitted) SDG&E transmission line. One-third (90 MW) of the electrical output of the EAX steam turbine can be exported to the U.S. only over SDG&E's existing transmission line. The remaining electrical output of the EAX unit (EAX-A, EAX-B, and two-thirds [180 MW] of the EAX steam turbine, for a total capacity of 500 MW) is designated to the Mexico market and is connected directly to the Mexican electrical grid. However, at times, there may be as much as 40 to 50 MW of the capacity of the EAX unit designated to the Mexico market that would be available for export to the U.S. over the existing SDG&E transmission line.

Sempra's transmission line would connect SDG&E's IV substation with the Termoeléctrica de Mexicali (TDM) power plant, which consists of two 170-MW gas turbines operated in a combined-cycle mode with one 310-MW steam turbine, for a total electrical capacity of 650 MW. To limit emissions of NOX, the gas turbines are equipped with low-NOX burners and SCR. The TDM power plant is not connected to any other transmission line and, therefore, could export all of its electrical output to the U.S. only over the proposed transmission line.


DOE and BLM analyzed the following four alternatives in the EIS:

No Action: Deny both permit and corresponding ROW applications. This presents the environmental impacts in the U.S. as if the lines had never been constructed and provides a baseline against which the impacts in the U.S. of the action alternatives can be measured in the absence of Presidential permits and corresponding ROWs.

Proposed Action: Grant one or both permits and corresponding ROWs. This sets forth the impacts in the U.S. of constructing and operating the line(s) from the Mexico power plants, as those plants are presently designed.

Alternative Technologies: Grant one or both permits and corresponding ROWs to authorize transmission lines that connect to power plants that would employ more efficient emission controls and alternative cooling technologies.

Mitigation Measures: Grant one or both permits and corresponding ROWs to authorize transmission lines whose developers would employ off-site mitigation measures to minimize environmental impacts in the U.S.

DOE's preferred alternative in the EIS was to grant a Presidential permit to both Sempra and Intergen as their projects are presently designed.

In addition to the applicants' proposed transmission line routes, DOE and BLM analyzed two alternatives, eastern and western, both of which would be located on BLM land.

Analysis of Environmental Impacts

The EIS analyzes impacts in the U.S. from the four alternatives and the three alternative transmission line routes for each of the following resource areas: Geology, soils and seismicity; water resources; air quality; biological resources; cultural resources; land use; transportation; visual resources; noise; socioeconomics; human health; and minority and low-income populations, plus cumulative impacts. The analysis includes issues that the court found insufficiently developed in the EA: impacts from water consumption by the power plants, particularly on the Salton Sea; impacts on air quality from power plant emissions of ammonia; impacts on global warming from carbon dioxide emitted from the power plants in Mexico; and cumulative impacts from the operation of the power plants in combination with existing and potential future power plants. DOE and BLM made conservative assumptions in the EIS. Thus, the actual impacts likely would be less than those estimated in the EIS.

For geology, soils and seismicity, land use, transportation, visual resources, noise, socioeconomics, and minority and low-income populations estimated impacts were generally low and very similar for all alternatives, including the No Action alternative. Several resource areas have been the subject of significant public concern, and while the impacts to these areas are also low and very similar, they merit additional explanation here.

Water Resources and Associated Biological Resources: The proposed projects would cause impacts to two major water resources: the New River and the Salton Sea. The New River originates in Mexico and flows north to the Salton Sea in California. The Sea, which has no outlets, is much saltier than the ocean and is increasing in salinity because evaporation concentrates the dissolved salts that enter the Sea, primarily in runoff from irrigated farmland. The fish that live in the Sea are species that tolerate high salinity. Start Printed Page 21192

Water use by the power plants for cooling and steam generation reduces flow in the New River and inflow to the Salton Sea, thus increasing the salinity of these water bodies, a key environmental issue for both. Most of the water withdrawn from the nearby sewage lagoons (Zaragoza Oxidation Lagoons) for use in the power plants is lost to evaporation, but about 20% of that withdrawn is discharged to the New River. (If it were not withdrawn for use in the power plants, the water lost to evaporation would enter the New River.) The water treatment plants at the two power plants purify the untreated, withdrawn water before use, and thus reduce the amount of pollutants, including dissolved solids that contribute to salinity, entering the New River. The resulting lower level of pollution in the river, indicated by lower chemical oxygen demand, would improve the survival of fish and invertebrates under all alternatives. However, because water is used by the power plants and stream flow is reduced, the salinity of the river is increased.

All alternatives would cause increases in New River salinity. Under the No Action alternative, the estimated salinity increase in the New River at the international boundary (where the river enters the U.S.) would be less than 3.7%, due to operation of the EAX unit (three gas turbines and a steam turbine), which is not associated with the proposed transmission line. The Proposed Action alternative, with all turbines at both power plants operating, would result in the greatest salinity increase in the New River, 5.6%. The use of a parallel wet-dry cooling system under the Alternative Technologies alternative would reduce the amount of water used by the power plants by as much as 56% and produce the smallest impact on salinity (an increase of about 2%) in the river. These estimated salinity increases would not adversely affect biological resources in the river or the adjacent constructed wetlands that draw water from the river because salinity would remain below the 4,000-milligrams per liter (mg/L) water quality objective for the Colorado River Basin and would not exceed the salinity tolerances of wetland plants.

The current salinity of the Salton Sea is about 44,000 mg/L. Salinity is increasing by about 1% per year under baseline conditions. Operation of both power plants under the Proposed Action alternative would reduce inflow of water to the Salton Sea by about 0.8%, thus reducing its volume by about 0.1%, lowering its elevation by an estimated 0.6 inches (1.5 cm), and decreasing its surface area by about 97 acres. Other alternatives, including No Action, would cause smaller reductions in the Sea's volume, elevation, and surface area. Under all alternatives, the reduced surface area would reduce evaporation from the Sea, offsetting water losses from the power plants, so the Sea would stabilize at its slightly lower volume, elevation, and surface area. The decrease in volume would increase the salinity of the Sea. The Proposed Action would increase salinity by about 63 mg/L (0.14%); other alternatives would cause smaller salinity increases.

After these initial changes, the Proposed Action alternative would add 0.19 mg/L (0.04%) to the Sea's annual salinity increase. Lower power plant water use due to fewer units operating under the No Action alternative and use of wet-dry cooling under the Alternative Technologies alternative would result in slightly smaller salinity increases than under the Proposed Action alternative. Under the Mitigation Measures alternative, water conservation measures in the region (for example, lining irrigation canals, reducing evaporative losses, or fallowing farmland) could offset water use by the power plants and offset these salinity impacts by allowing more water to flow into the Salton Sea.

The U.S. Department of the Interior's Bureau of Reclamation considers a salinity level of 60,000 mg/L to be a value that would be detrimental to Salton Sea fishery resources. Under baseline conditions (with no power plants operating) DOE and BLM estimated that the Salton Sea would reach this critical level of salinity in approximately 36 years. Under the Proposed Action alternative, the alternative that would yield the greatest rate of increase in salinity, the Salton Sea would reach this critical level approximately 4 days sooner.

Air Quality and Human Health: Under all of the alternatives, emissions from three possible sources would have an impact on the air quality in Imperial County: Power plant emissions blown into the U.S. by the prevailing winds, emissions from the increase in the exposed lakebed of the Salton Sea caused by reduced depth, and emissions caused by the construction of the proposed transmission lines. It is important to note that emissions from the power plants and from the exposed lakebed are not subject to regulation under any portion of the Clean Air Act. Only the direct emissions associated with construction of the transmission lines are subject to the conformity provisions of the Clean Air Act. The foregoing notwithstanding, DOE and BLM have used parameters contained in Clean Air Act regulations as benchmarks against which to measure the magnitude of the impacts. However, use of these benchmarks is not intended to imply any regulatory applicability.

The public has shown more concern about impacts from the power plants than from the transmission lines. The agencies' assessment, as discussed below, indicates that both the power plants and the transmission lines would have very small impacts on air quality and human health in Imperial County.

California's Imperial Valley, the region in which the proposed transmission lines would be built, is included within the Salton Sea Air Basin, a California air management district. Air quality in the Salton Sea Air Basin is generally poor due, in part, to windblown dust from the natural features of the region (e.g., desert soils) combined with human activities, such as construction, extensive agricultural activities, and traffic on paved and unpaved roads. Imperial Valley is in the same geographic air basin as the power plants in Mexico.

The Salton Sea Air Basin is designated as a non-attainment area for ozone, a non-attainment area for particulate matter of less than or equal to 2.5 micrometers in diameter (PM2.5), and a serious non-attainment area for particulate matter less than or equal to 10 micrometers in diameter (PM10). At the international border, the City of Calexico is designated a non-attainment area for carbon monoxide (CO). The area near the border crossing also shows increased levels of NOX attributed to vehicles.

In addition to the pollutants listed above (i.e., ozone, PM2.5, PM10, CO, and NOX), the agencies considered potential impacts from the alternatives due to emissions of other substances, including carbon dioxide (CO2), volatile organic compounds (VOC), and ammonia. Where appropriate, DOE and BLM compared modeled maximum concentrations to EPA's Significant Impact Levels (SLs), using the SLs as a benchmark. Levels that fall below SLs can be regarded as having negligible impacts on air quality and human health.

Particulate matter: Construction and maintenance of the transmission lines, which would occur under all the action alternatives, would be a source of dust (PM10). Over the course of several months, traffic and other activities related to construction along the proposed routes would result in the emission of approximately 11.4 tons of PM10 that would be localized mainly at the construction site. This emission rate Start Printed Page 21193is less than the 70 tons/yr emission threshold below which activities are exempt from review of conformity to the state implementation plan for the Clean Air Act that applies in serious PM10 nonattainment areas. Long-term impacts associated with the lines would be limited to generation of dust during periodic maintenance; these impacts are expected to be negligible. The No Action alternative would, of course, have no such impacts.

Under all alternatives the natural gas-fired power plants in Mexico would emit PM10 from their stacks and cooling towers. Under the Proposed Action alternative, direct emissions of PM10 are estimated to be 732 tons/yr, resulting in a concentration increase at a maximum receptor point in the U.S. of less than half of the SL value of 5 micrograms per cubic meter (μg/m 3) as a 24-hour average. Under the Mitigation Measures alternative, of several measures that DOE and BLM identified, road paving would have the greatest potential for reductions in PM10 that could offset power plant emissions. For example, paving 50 identified road segments in Imperial County totaling 23 miles (37 km) is estimated to reduce fugitive dust (PM10) emissions by about 650 tons/yr. Under the Alternative Technologies alternative, use of a parallel wet-dry cooling system would reduce power plant efficiency, requiring additional fuel consumption for a given electrical output. This would result in an increase in most emissions but a reduction in emissions of PM10 from the wet cooling towers.

PM10 would also be formed under all alternatives when NOX released by the power plants combines with ammonia (either already in the ambient air or released in small amounts by the power plants) under appropriate conditions to form ammonium nitrate particles, but the increased concentration of PM10 is expected to be small, less than 1 μg/m 3 as a 24-hour average. (Health impacts from ammonia emissions are discussed below under Hazardous Air Pollutants and Ammonia.)

Another source of PM10 under all alternatives would be wind-blown dust from lakebed exposed by a lower water level in the Salton Sea. The agencies estimated that dust emissions from an increase in exposed lakebed of the Salton Sea would be less than 10 tons/yr for the Proposed Action alternative.

DOE and BLM assessed potential impacts of PM10 related to the power plants on asthma rates in the U.S. in the Final EIS, after public comments on the Draft EIS expressed concern that the project would result in a large increase in the number of cases of asthma, many of which would require hospitalization. The agencies' analysis showed that the expected increase in asthma hospitalizations in Imperial County from increases in PM10 attributable to power plant emissions is conservatively estimated to be less than one case per year.

Ozone, VOC, and NOX: Asthma and other upper respiratory diseases are associated with high levels of ozone in areas such as Imperial County. Ozone could be formed from combination of NOX and VOC emitted by the gas-fired power plants in Mexico. DOE and BLM determined that NOX and VOC emitted during operation of the power plants under all alternatives would result in minimal increases in ozone levels under typical meteorological conditions. The maximum estimated increase in concentrations of ozone would be generated by the Proposed Action alternative (0.8 parts per billion (ppb) averaged over a one-hour period, or 0.9% of the 1-hour California Standard of 90 ppb). Therefore, DOE and BLM expect no adverse health impacts from additional ozone under any alternative.

Hazardous Air Pollutants and Ammonia: Analysis of the potential cancer and non-cancer impacts in the U.S. from hazardous air pollutants emitted by the power plants in Mexico showed that emission levels would not be large enough to produce adverse human health impacts when compared to California cancer and non-cancer impact thresholds. DOE and BLM estimated that the increase in ammonia concentrations in the U.S. from the SCRs installed at the power plants would be a maximum of 4.05 μg/m 3 for any one-hour period and a maximum of 0.06 μg/m 3 annually under the Proposed Action alternative. This increased level of exposure would be less than 0.16% of the significance threshold based on California risk assessment procedures for acute exposure and less than 0.028% of the significance threshold for chronic exposure, i.e., far below the levels that could result in health impacts.

Carbon monoxide: The highest CO emissions from the power plants would be under the Proposed Action alternative and would yield a maximum estimated increased concentration of CO at any location in the U.S. over an 8-hr period of 3.92 μg/m 3. This is only 0.8% of the SL of 500 μg/m 3, so no adverse impacts to human health would be expected. Under the Alternative Technologies alternative, the agencies analyzed the effect of adding an oxidation catalyst on the LRPC gas turbines that would connect to Intergen's proposed transmission line. (The turbines at the TDM power plant that would connect to Sempra's transmission line are already so equipped.) Installation of an oxidizing catalyst to the two LRPC export turbines would reduce the maximum estimated increased concentration of CO at any location in the U.S. over an 8-hr period to 0.647 μg/m 3, or 0.13% of the SL.

Carbon dioxide: CO2, a greenhouse gas, has been linked to global warming. Emissions of CO2 would be produced by the Mexico power plants under all alternatives. Under the Proposed Action alternative, the export turbines at the power plants would produce an estimated 5,186,000 tons of CO2 per year, which would be a very small fraction of total U.S. (0.088%) and global emissions (0.023%). The lowest amount of CO2 emissions would occur under the No Action alternative, which would produce 3,889,500 tons per year of CO2, or 0.066% of total U.S. and 0.017% of global emissions. Expected impacts to global climate change from all alternatives is expected to be negligible.

Alternative Transmission Line Routes: The agencies analyzed two alternatives, western and eastern, to the proposed routes for the transmission lines. The assessment showed that the choice of route location would make small differences in PM10 emissions and in impacts to biological and cultural resources. The assessment found no potential adverse health effects from exposure of residents to electric and magnetic fields under any of the action alternatives on any route because the nearest residents would live outside the influence of the lines.

PM10 emissions from transmission line construction would be about 11.4 tons for the proposed routes, 14.4 tons for the western alternative routes, and 12.3 tons for the eastern alternative routes. Periodic maintenance activities would generate a maximum of 0.08 ton/yr for the proposed route and slightly more for the longer alternative routes.

No plant or animal species listed as proposed, threatened, or endangered by the U.S. Fish and Wildlife Service or California Department of Fish and Game were observed during surveys for this project. No BLM-sensitive plant species were observed within the survey corridor. Three BLM-sensitive animal species were observed within the corridor: flat-tailed horned lizard, western burrowing owl, and prairie falcon. The prairie falcon is not expected to nest on site. Potential adverse impacts to plants and animals from the construction of the transmission lines on BLM land would be similar but larger for the alternative Start Printed Page 21194transmission line routes than for the proposed routes. These impacts would be small and short-term, lasting about five months, and in most cases would be mitigated during construction. For example, the applicants would be required to construct the proposed transmission lines as much as possible during the flat-tailed horned lizard's dormant period, November 15 to February 15.

Impacts to cultural resources from line construction under any route would be small due to the relatively small footprint of the transmission towers and the short length of the routes. Use of the western or eastern alternative routes would be expected to have a lower potential for impacts to cultural resources, because these routes are not located along the shoreline of an ancient lake (Lake Cahuilla) where there is a higher potential to encounter cultural resources. Any potential impacts to cultural resources would be mitigated during construction by following the treatment plan developed and approved by the California State Historic Preservation Officer.

Cumulative Impacts: Cumulative impacts analysis in an EIS places the effects of the proposed action into a broader context that includes impacts from other past, present, and reasonably foreseeable future actions potentially affecting the same environmental resources. The principal ongoing projects that would affect the Salton Sea, reducing its volume, elevation, and surface area and increasing its salinity, are the Imperial Irrigation District Water Conservation and Transfer Project and the Mexicali II Wastewater Treatment Project.

A recent study by the U.S. Bureau of Reclamation indicates that the Water Conservation and Transfer Project alone is projected to cause the salinity of the Salton Sea to reach the critical level of 60,000 mg/L four years sooner than under baseline conditions. The Mexicali II Wastewater Treatment Project extracts waste water from the New River and returns the water to a canal that does not flow back to the river.

Various projects, however, are contributing or are planned to contribute positive changes to the New River and the Salton Sea. For example, the U.S. Bureau of Reclamation has constructed a wetland adjacent to the New River that is the first of 40 or more wetlands proposed for construction. The wetlands, together with the Mexicali II Wastewater Treatment Project and all alternatives, would reduce pollutant loads and thus improve biological habitat in the New River. Looking to the future, sponsors of the Salton Sea Restoration Project hope to stabilize the Sea's elevation, reduce salinity levels, and improve wildlife habitat, but restoration activities have not been specified in sufficient detail to be assessed.

Concern has been expressed that numerous additional power plant projects have been or will be planned for the border region. DOE and BLM thoroughly researched this issue consulting with the California Energy Commission, the Comision Federal de Electricidad in Mexico, and other agencies and organizations in California and Mexico to identify all existing and proposed power plant projects, and to identify trends that could contribute to this kind of development. DOE and BLM found no existing, planned or proposed plants in Mexico that would contribute impacts to the Imperial Valley or the Salton Sea Air Basin. DOE and BLM did identify and analyze the combined air quality impacts of three Californian power plant projects: The CalEnergy Geothermal Project, a project under development in the Salton Sea Air Basin, and two proposed natural gas-fired power plants, Blythe Energy, located just north of the Basin, and Wellton-Mohawk located 50 miles east of the Basin.

DOE and BLM also examined other planned and ongoing activities in the region as well as population and industrial trends that could contribute impacts to air quality in the Basin. Taken as a whole, the Salton Sea Air Basin is projected to experience increases in PM10, NOX, CO, and ammonia from sources other than the TDM and LRPC power plants. As the total amount of these pollutants from other sources increases, the small percentage contribution of pollutants from the Proposed Action alternative will become even smaller.

Environmentally Preferable Alternative

DOE has identified the Mitigation Measures alternative as the environmentally preferable alternative with the caveat that the effectiveness of this alternative would depend on the extent to which it is in fact possible to implement such measures. Implementation of mitigation measures such as the paving of roads, expanding the use of compressed natural gas in motorized vehicles, retrofitting emission controls to Imperial Irrigation District power plants, and updating the diesel engines of agricultural vehicles have the potential of mitigating many of the potential impacts to air quality. Other mitigation measures such as lining irrigation canals, fallowing farmland, and transferring ground water into the New River and Salton Sea have the potential of mitigating the potential impacts to the Salton Sea.

Implementation of these and other measures described in the EIS could result in the lowest overall impacts of all evaluated alternatives. Whether, and the extent to which, these measures can in fact be implemented, however, can depend in part on factors outside the applicants' control. Most of the mitigation measures would require some degree of approval and cooperation from local and state agencies for their implementation. Also, existing local agreements could diminish the positive effect of some of the measures.

DOE believes that the No Action alternative is less environmentally preferable than the Mitigation Measures alternative. The No Action alternative would not completely avoid the environmental impacts from operation of the power plants in Mexico because it would not reduce any impacts from the EAX turbines, which would operate even in the absence of the proposed international transmission lines. Also, under the No Action alternative, if Sempra and Intergen connected the export turbines at their Mexico power plants only to the Mexican power grid, Sempra and Intergen would not need Presidential permits and thus they would not be subject to any permit conditions that could potentially reduce environmental impacts.

Comments Received on the Final EIS

DOE received four comment documents on the Final EIS. EPA Region IX commented that DOE and BLM had addressed EPA's earlier comments with respect to water and air quality impacts: “EPA is pleased that most of the issues identified in the [Draft EIS] have been addressed in the [Final EIS]. In response to comments from the EPA, DOE provided additional discussion on water mitigation measures, and the cumulative impacts of increased water usage and discharge by the increasing population of Mexicali. The document also clarifies the limitation and uncertainties of the ozone modeling analysis.”

EPA also noted that: “* * * off-site mitigation measures to reduce basin-wide air emissions remain as a separate alternative in the FEIS and are not incorporated into the proposed action.” EPA suggested that one way to address the limitations in ozone modeling and to ensure that there would be no net increase of air pollution in the Imperial County Region would be for this ROD to include a commitment to continue to work with stakeholders to support and Start Printed Page 21195encourage off-site mitigation measures. DOE appreciates EPA's recognition that the agencies have addressed EPA's earlier concerns and has considered these new comments in decision making.

The Imperial County Air Pollution Control District again raised issues that it had raised on the Draft EIS concerning air quality, health, and mitigation. DOE and BLM specifically addressed these issues in the responses to comments section of the Final EIS and also added descriptions and explanations throughout the main text of the EIS.

A third commenter stated that the EIS was hard to read and comprehend. DOE and BLM attempted to make a highly technical project as understandable as was reasonable. A fourth commenter expressed concern that the companies had overstated the cost of the SCR and wet-dry cooling systems. DOE does not agree that costs are overstated and notes that SCR systems have been installed regardless of cost.


DOE has decided to implement the Proposed Action alternative, which was identified as DOE's preferred alternative in the EIS. Accordingly, DOE will grant a Presidential permit to both Sempra and Intergen that allows each applicant to construct, operate, maintain, and connect a separate double-circuit, 230-kV electric transmission line that extends south from SDG&E's existing Imperial Valley substation, crosses the U.S. international border in the vicinity of Calexico, California, and connects to their respective natural gas-fired power plants, as those plants are currently designed, located in Mexicali, Mexico. The permits will specify that the permitted electric transmission lines must be connected to power plants that are designed, constructed, and operated in accordance with the specifications upon which DOE and BLM based the analyses contained in the EIS. These specifications include the use of wet cooling systems, water treatment plants, and all air pollution control systems that already exist or are scheduled for installation. Any permit issued may be modified or revoked by the President of the United States without notice, and by DOE after public notice, and may also be amended by DOE after proper application to DOE.

Before granting a Presidential permit, DOE also considers whether a proposed international electric transmission line would have an adverse impact on the reliability of the U.S. electric power supply system. In reaching this determination, DOE considers the operation of the electrical grid with a specified maximum amount of power transmitted over the proposed line. In this instance, DOE is in receipt of technical studies that demonstrate that the southern California electrical grid would remain reliable with the existing capacity of the TDM and LRPC export units connected to it. Therefore, each permit will also contain an electric reliability condition that limits the instantaneous rate of transmission (i.e., electric power) over the permitted transmission lines to the existing generating capacity of the respective power plants. Any change in the authorized operation or connection of the permitted facilities requires prior approval by DOE. Therefore, connection of additional generating capacity to either of the permitted international transmission lines would require the owner of the permitted facilities to notify DOE and to seek an amendment of its Presidential permit. Amendment of a Presidential permit requires an additional proceeding in which DOE would need to determine that the proposed modification to the permitted facility or its operation or connection is in the public interest. This determination would include another review of the impact on electric reliability and on the environment, and any other factors that DOE may also consider relevant to the public interest.

Basis for Decision

In arriving at its decision, DOE has considered the continuing need for additional electrical supplies in the region, the low potential environmental impacts, the lack of adverse impacts to the reliability of the U.S. electric power supply system, the practicality or the availability of the alternatives, and public comments provided during the preparation of the EIS

DOE did not select the No Action alternative because it would not address the need for power in the region. The need for electric power supplies in the southern California area has been well documented in various ways over the past several years. Most recently, on January 19, 2005, the California Independent System Operator (Cal-ISO) issued a report entitled, “2004 Cal-ISO Controlled Grid Study,” in which it notes that, “In years 2006 and 2009, at the import levels modeled, and with all generators (new and old) on-line there is barely enough generation available in order to bring the system back within normal operation after all single and double contingencies” (that is, for example, outage of one or more critical transmission lines, transformers, or generating units).

DOE has determined that the potential impacts in the United States from the Proposed Action alternative are expected to be small, as discussed above.

Under the Alternative Technologies alternative, the only additional technology identified that could reduce air emissions was the addition of an oxidizing catalyst on the LRPC gas turbines. (The TDM power plant already has an oxidizing catalyst installed.) The effect of this additional technology would be to reduce maximum increases in concentrations of CO in Imperial County. However, because the increase in CO concentrations for the Proposed Action alternative is so far below the SL for this pollutant, the addition of this technology to the LRPC plant would not appreciably alter the potential for human health impacts.

Incorporation of parallel wet-dry cooling systems under the Alternative Technologies alternative would reduce consumption of water by the Mexico power plants. However, this reduction of water use would produce negligible improvements in the already small impacts associated with the Proposed Action. Moreover, use of this technology would reduce the efficiency of the Mexico power plants, requiring greater fuel input for the same electrical output and increasing most emissions except for PM10.

While the Mitigation Measures alternative presents a slate of activities that might offset some of the impacts of the power plants, it is not clear which, if any of them will be implementable in fact. In the case of water mitigation measures, any water that may be conserved if these measures could be implemented would likely be diverted to other water uses in the region, and would not be used to offset the reduced inflow of water to the Salton Sea attributable to the Proposed Action. Given the low impacts to air and water expected from the power plants, DOE does not believe that the expense of such measures, when viewed in the light of the uncertainty of their results, warrants their imposition.

For the foregoing reasons, DOE has decided to implement the Proposed Action alternative as defined in the EIS, but with the conditions noted in the Decision section above.

Floodplain Statement of Findings

In the EIS, DOE and BLM assessed the impacts of the proposed action on floodplains. The proposed and alternative routes for the proposed transmission line would cross Pinto Wash and its 100-year floodplain. A map of this floodplain is provided in the Start Printed Page 21196EIS. See ADDRESSES for information on obtaining a copy of the EIS. A maximum of two lattice tower footings for each transmission line would be in the Pinto Wash 100-year floodplain for the proposed or alternative routes. Construction of footings for the support structures would introduce temporary disturbance into this 100-year floodplain. Cylindrical sections of the footings 3 to 4 ft (0.9 to 1.2 m) in diameter would permanently protrude above the ground surface. There is no practicable alternative to placement of structures in the floodplain, but the floodplain assessment found that neither the temporary disturbance during placement of these footings nor their permanence would result in change to conditions in the floodplain, flooding, or floodplain function.

With respect to the floodplain of the New River, the assessment found that changes in water flow and depth produced by power plant operations would lie well within the variability of the flows for the New River. All alternatives, including No Action, could result in a small reduction in maximum flood elevation, but this change would have no practical effect on the incidence or extent of floods or floodplain function.

Start Signature

Dated: April 18, 2005.

Kevin Kolevar,

Director, Office of Electricity and Energy Assurance.

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1.  On April 13, 2005, the Secretary of Energy transferred the authority to grant Presidential permits from the Office of Fossil Energy to the Office of Electricity and Energy Assurance.

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2.  Throughout court proceedings and the EIS process, BCP has been referred to as Intergen. This naming convention was used to avoid confusion and because that was the name by which the court knew the permit applicant. This naming convention also will be used throughout this ROD.

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3.  On August 29, 2002, Sempra and Termoeléctrica U.S., LLC (T-US) jointly filed an application with DOE for the voluntary transfer from Sempra to T-US of the facilities authorized by Presidential Permit PP-235, which was issued to Sempra by DOE on December 5, 2001. Sempra and T-US, both indirect wholly-owned subsidiaries of Sempra Energy, a California corporation, requested the transfer of Presidential Permit PP-235 to enable the parties to effectuate an internal corporate reorganization that would result in T-US owning, operating, and maintaining the international transmission facilities as an exempt wholesale generator. After an appropriate administrative proceeding, on November 12, 2002, DOE issued Presidential Permit PP-235-1 to T-U.S. The name Sempra will be used in this ROD because that was the name commonly used in the court proceeding. However, the permit that DOE has decided to issue will be issued in the name T-US.

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[FR Doc. 05-8200 Filed 4-22-05; 8:45 am]