Meeting the energy needs of Southern California

Frequently Asked Questions


Soda Mountain Solar Project

What is the Soda Mountain Solar Project?

The Soda Mountain Solar (“SMS”) project is a 287 MW solar power generating facility. It will employ photovoltaic (“PV”) panels to convert sunlight into electricity.

Where is the project located?

The project will be located on 1,767 acres of land in a 10-square mile valley between the North and South Soda Mountains in the Mojave Desert about 6 miles southwest of Baker, California. It is adjacent to and on the southeast side of interstate highway I-15, which bisects the valley.

What are the closest communities to the project?

There are no permanent residences in the valley where the project is located. As a consequence, there are no communities that would directly experience the project. The closest community is Baker, a small town of approximately 700 people located 6-7 miles northeast of the project on I-15. The nearest city is Barstow, approximately 60 miles to the southwest of the project on I-15. The Barstow area has a population of about 31,000.

Site Selection

How was this site selected?

The selection process began with a high-level screening of a broad area of southern California based on the following criteria that are critical to making a site suitable for a solar project: high year-round availability of direct sunlight; a large contiguous parcel of land with relatively flat slope; minimal vegetation; proximity to an existing major electric transmission line; and existing vehicular access. In addition to having these physical characteristics, use of a site for a solar project must also satisfy a variety of environmental requirements and be consistent with land use policies. Sites that met the initial screening criteria were inspected in person and meetings were held with local BLM offices to elicit more detailed site information regarding site availability and environmental and land use restrictions on the use of sites. The final stage of site selection was to have an environmental consultant review the small number of sites that had passed the multiple prior stages of screening.

How many sites did the environmental consultant conclude satisfied all of the criteria?

Only one site satisfied all of the criteria: the Soda Mountain site.

What did the subsequent review of the site for the EIS reveal regarding the suitability of the site for a solar project?

For the environmental impact statement, detailed studies and surveys were conducted to examine a broad range of potential impacts on sensitive species, water resources, and cultural resources. From these studies, it is clear the impacts of the project at the selected site are generally less than the impacts would be at sites within Solar Energy Zones, at other sites that have been approved for solar projects, and at the alternative sites that have been suggested for the project by third parties. The Soda Mountain Solar project is unique in its lack of special status plants and no endangered species other than a single tortoise that was found after multiple project surveys.

Why was the project not sited in a Solar Energy Zone (“SEZ”)?

The SMS site selection process took place in 2007. BLM did not establish the SEZs until 2012, five years later. The SMS site satisfies all of the criteria that were applied in identifying SEZs, with the exception that in a few locations, the slope of the SMS site slightly exceeds the slope criterion applied in identifying SEZs. It is not surprising that the SMS site meets virtually all of the criteria to be a SEZ as the criteria employed to select the SMS site were very similar to the criteria used to identify areas suitable for a SEZs. It is important to note that in none of the SEZ areas would the environmental impacts of a solar project be less than at the project site.

During the environmental review of the project, some parties suggested that other sites had more favorable environmental characteristics than the site SMS had chosen. Has SMS evaluated those other sites?

SMS examined each one of the alternative sites. In each case, a solar project at that site would have greater environmental impacts than is the case with the chosen site. In some cases, the alternative sites were not adjacent to a transmission line—as is the SMS site—so that such sites would create significant off-site environmental impacts associated with the construction of a transmission line. Other impacts at the alternative sites that would have been greater than at the selected site included impacts on various special status species and protected cultural sites.

Existing disturbance in project area

Is there currently any utility or transportation infrastructure located in the valley?

A variety of utility and transportation infrastructure is already located in this valley: a busy, four-lane, divided interstate highway; two interchanges to provide access to this highway; a 500 kilovolt electric transmission line; a 115 kilovolt electric transmission line; an electric distribution line; two petroleum pipelines; two fiber optic cables; three cell towers; service roads associated with these utilities; a service station with a mini-market; overnight accommodations for the employees at the service station; a portion of the Rasor Off Highway Vehicle Area and an access road to this Area; and the crumbling remnants of the former Arrowhead Highway. Virtually every location within the valley is exposed in one way or another to one or more of these infrastructure elements.

Are future infrastructure projects contemplated for this valley?

Large portions of this valley have been designated by the federal government as a Section 368 Energy Corridor. This means it is a preferred route for future utilities such as transmission lines and pipelines. There are several major utility and transportation projects that might be located in the valley in the future: the route of the approved XpressWest high-speed rail line would pass through the valley; it is likely that at some point the old 115 kilovolt transmission line will be replaced by a higher voltage line; I-15 carries a high volume of traffic which is only expected to grow in the future.

Regional economic impact

How many jobs will the project create?

During the construction period, the average workforce at the project site is expected to exceed 200 workers, with the workforce peaking at nearly 300 people. These on-site jobs will include electricians, ironworkers, laborers and supervisory personnel at an average total compensation level of over $62,000 per year. SMS intends to use union labor, and it is anticipated that most of the construction workers would come from San Bernardino County. During the 30-year operations phase, the total full-time-equivalent operating staff at the plant will number 25-40 workers with annual compensation (including benefits) estimated to be $84,000.

What will be the regional economic impact of the project?

Including both the direct expenditures of the project and the indirect local effects of those expenditures, the economic impact on San Bernardino County is estimated to be $756 million during the construction phase. During the operating phase of the project, the total regional economic impact of the project, when both direct and indirect effects are included, is projected to be nearly $10 million per year.

What revenues will local governments receive?

Sales tax revenues to the county and other local jurisdictions are generated primarily during the construction phase of the project and depend on the extent to which the project site is the “point-of-sale” address for equipment, especially the panels and inverters. Total sales tax receipts by the county and other regional local governments are expected to be at least $700,000 and could be as high as $11 million if the point-of-sale for the bulk of the equipment were the project site.

Effect on Mojave National Preserve

What is the impact of the project on the Mojave National Preserve?

The project site abuts a portion of the western boundary of the Preserve for a stretch of approximately two miles. To put this in perspective, the Preserve has a perimeter of approximately 200 miles; the project abuts only about one percent of the perimeter. Looked at another way, the Preserve covers 1.6 million acres of land while the project includes only 1767 acres; the project’s footprint is about one-tenth of one percent of the area of the Preserve. The project site is very small compared to the size of the Preserve and for this reason alone will have very little impact on the Preserve.

Is there any visual screening between the project and the Preserve?

Yes. A mountain range, a portion of the South Soda Mountains, runs along the boundary between the project and the Preserve. The boundary follows the high ridgelines in this range. This mountain range effectively blocks the view of the project from almost the entire Preserve.

From where in the Preserve would you be able to see the solar project?

From the tops of particular peaks in the South Soda Mountains, along the boundary between the project site and the Preserve, the project would be visible from the Preserve side of the boundary. However, these mountains are in a remote section of the Preserve; Preserve personnel estimate that perhaps two people visit these hills each year. Because of the topography of the region, the next best viewing area would be certain locations in the Preserve, 10-20 miles away from the project site, where the elevation rises high enough to so that one can see through a break in the South Soda Mountains. Given the natural haziness of 10-20 miles of air and the dark façade of the distant mountains that form the backdrop to the west, the solar arrays, which are also dark, would be imperceptible.

Desert tortoise

Is the project site a good habitat for desert tortoise?

Generalized habitat suitability models predict the valley between the North Sodas and the South Sodas could be high-quality habitat for desert tortoise. However, specific site conditions indicate that this is not actually the case. The models do not account for the anthropogenic disturbance at the site: vegetation at the site is sparse; soils are very rocky; and good tortoise habitat generally occurs at elevations higher than that of the valley. There are two additional attributes that make the valley a less favorable habitat for desert tortoise: It is known that high-volume highways deter desert tortoise for as much as 2.5 miles, which means that I15 effectively deters tortoises from the entire valley in which the project is located. Similarly, a widely-used access road to the Rasor Off-Highway Vehicle Area passes through the project site and disturbances related to off-highway vehicle use also deter tortoises from the Soda Mountain Valley.

Have desert tortoises been found on the project site?

Multiple intensive site surveys, covering the entire site as well as adjacent land, discovered only one tortoise at the project site along with limited indications of tortoise habitation (burrows and tracks). Based on these survey results, the conclusion by the wildlife biologist who evaluated tortoise impacts as well as the US Fish and Wildlife Service was that tortoise numbers are low on the project site; the specific estimate was that there are two tortoises on the project site.

Bighorn sheep

Is the project site used by bighorn sheep?

Bighorn sheep’s preferred habitat consists of steep, rocky terrain (greater than 10% slopes) which provide shelter and shielding from predators and proximity to water sources. In contrast, the SMS site is located in a valley lowland with flat terrain (generally 2-4% slopes, as is typical for a solar project), and it is far from water sources. Sheep may forage for short periods in the spring in flat valley lowlands adjacent to the mountains, but it is not their primary habitat. Furthermore, large portions of the project site are impacted by the noise and active visual disturbances associated with I-15, the Rasor Road service station, and the Rasor Off-Highway Vehicle Area.

Is the project site a good migration route for bighorn sheep?

No, it is not. Bighorn sheep favor migration routes with 10% or greater slope and with access to escape terrain and water sources. The project site is located in a section of the valley where the North Sodas and South Sodas are generally separated by two or more miles of flat terrain with no water sources and where the sheep are highly exposed to predators. More favorable locations for habitat connectivity or migration between these segments of the Soda Mountains are at the northern and southern pinch points of the valley where steep terrain can be found closer to the highway. The high elevation pinch point at the northern end of the valley near Zzyzx Road is considered to be a particularly suitable location for future efforts to induce sheep to cross the highway. At this location, about one mile north of the northernmost extent of the project site, the terrain close to both sides of the highway is quite hilly, providing a more natural route for the sheep; there are historical bighorn sheep trails in this area, evidence that bighorn sheep used this area for intermountain migration prior to construction of the I-15 freeway.

Do bighorn sheep currently migrate freely in the Soda Mountains?

No, they do not. A busy, four-lane interstate highway, carrying 80,000 vehicles a day, separates the North Sodas from the South Sodas. Highways are known to be major barriers to bighorn sheep migration. When I-15 was built decades ago, it effectively created a barrier to migration of bighorn sheep, cutting off the North Soda Mountains from the South Soda Mountains. Although there are occasional, anecdotal reports of individual sheep on the west side of I–15, the population in the North Soda Mountains was not sustainable after I-15 cut off the access from the North Soda Mountains to water sources at Soda Lake.

Aren’t there culverts and underpasses that sheep could use to cross I-15?

Although bighorn sheep are known to occasionally use culverts and underpasses to cross highways, they do so primarily where the culvert/underpass is adjacent to steep hills and the span is narrow. These conditions do not apply to the culverts under I-15 adjacent to the project site; those culverts are surrounded by flat terrain for long distances in all directions. Two webcams were installed by the California Department of Fish and Wildlife in 2012 to monitor use of the culverts by animals: one at Opah Ditch, the largest culvert under the highway adjacent to the project site; the other located northeast of the Zzyzx Road overpass, approximately one mile from the project site. The cameras have not recorded a single instance of a bighorn sheep passing through the culverts in the four years since the webcams were installed.

How will the project affect bighorn sheep in the South Soda Mountains?

After the solar arrays are installed, they will be visible from vantage points on the west facing slopes of the South Soda Mountains. However, aside from an occasional crew conducting maintenance or repairs on the panels, the solar arrays are silent and do not constitute an active visual disturbance. During the 24-30 month period of construction, there will be daytime noise and visual disturbance resulting from construction equipment and from work crews installing arrays and inverter systems. Construction proceeds sequentially from one array to another so that, at any one time, construction activity will be mostly concentrated on a particular segment of the site with the rest of the site having little to no activity. As a result, any one portion of the west facing slopes of the South Soda Mountains will be affected by nearby activity for only for a portion of the 24-30 month period.

What impact will the project have on the migration of bighorn sheep?

The project will enhance the likelihood that bighorn sheep migration between the South Sodas and the North Sodas will be restored. SMS has committed to take several actions related to encouraging the migration of the sheep: installing and maintaining “guzzlers”—water troughs—to induce the sheep to use culverts as a migration route; and conducting a 10-year monitoring study to document the effects of the project on bighorn sheep. SMS will also contribute a quarter million dollars to bighorn migration studies performed by CDFW. In addition, SMS has configured its array fields so as to leave wide paths between the South Soda Mountains and culverts so as to permit sheep to access the culverts.

Where would the guzzlers be placed?

SMS, under the direction of BLM and the California Department of Fish and Wildlife, examined a number of culverts and underpasses passing under I-15 in the vicinity of the Soda Mountains to assess which ones would be most likely to be adopted by the sheep as routes to use to move between the South Sodas and the North Sodas. While not in the project’s immediate vicinity, the underpass north of Zzyzx Road was determined to be the best choice for the introduction of guzzlers to induce the sheep to cross I-15 because its size is large, mountains come very close to the highway on both sides at this location, and it is close to historic bighorn sheep trails. SMS will pay to have the guzzlers put in place and, hopefully, the migration route between the two segments of the Soda Mountains, cut off decades ago by I-15, can once again be restored.

Water requirements

Where will the project’s water supply come from?

Several groundwater wells in the Soda Mountain Valley will supply water to the project.

What is the expected impact of the water taken from these wells on the regional groundwater basin?

The total water usage for all stages of the project for the entire duration of the project—including construction, operation, and decommissioning—is less than one half of one percent of the water in storage in the aquifer. During the operating period, the project’s annual consumption of water is only 24-41% of the annual recharge to the basin, which means the groundwater is replenished at a faster rate than the project extracts water. The project’s average annual consumption of water, including the construction and decommissioning periods, is 38-67% of the annual replenishment rate.

What would be the effect of the project’s water extraction on the Mohave tui chub at the MC Spring?

Water pumped for the project is a such a small fraction of the water in the aquifer that it would have no effect on the Mohave tui chub at the MC Spring, located on the other side of the volcanic Soda Mountains from the well. The MC Spring is 4.5 miles from the nearest production well proposed for the project. At that distance, the drawdown at the well due to the project’s water use would be only 0.0000068 feet, an insignificant and unmeasurable effect.

What would be the effect on the wells at the Town of Baker and at Rasor Road

The Town of Baker is over six miles from the closest production well for the project. The groundwater modeling and well pump test showed there will be no measurable effect on water wells or sources in Baker caused by water use at the SMS site. The Rasor Road groundwater well is on a bedrock ridge more than 1.5 miles from the nearest project production well and has a depth of 1000 feet into bedrock. It is not hydraulically connected to the saturated sandy alluvium in the valley and, as a consequence, the project’s water extraction will not affect this well.

What They’re Saying…

“…our organization and its affiliates are proponents of protecting our states’ precious resources, and preserving the natural beauty of our vast California deserts.  However, we believe there must be a balance of conservation and development.  We support the Soda Mountain Solar Project because we believe it represents this balance.”

Alex Artiaga

Business Manager, Laborer’s International Union Local 783