The EPA suggests the future of solar might be on the rooftop in the foreground rather than the desert in the background. | Photo: Walmart /Flickr/ Creative Commons License

As the state and federal agencies drafting a massive plan to zone the California desert for energy development struggle to put a record number of public comments online, one comment in particular may cause the document's authors even more work.

The public comment period on the draft Desert Renewable Energy Conservation Plan, known as the DRECP, closed Monday, and by the end of the day about 12,000 people had submitted comments on the draft plan. That's about one comment per page of the gargantuan document, which would determine the course of renewable energy development on 22.5 million acres of the California desert in seven counties.

Among the comments on the draft DRECP already made available on the plan's website is one from a key government agency charged with protecting the environment: the U.S. Environmental Protection Agency. And it the EPA's comment is taken seriously, the framers of the DRECP have a whole lot more work to do.

Though the EPA's comments (PDF) start out by commending the agencies that drafted the plan, EPA goes on to suggest that the plan is lacking in its examination of potential impacts to air and water, wildlife, and public health in the desert.

In addition, the EPA bluntly suggests that the DRECP's assumptions about the amount of renewable energy desert communities will need to provide the rest of the state are outdated, inflated, and in need of revision, and suggests that any desert energy development be focused on lands the EPA has already identified as disturbed or contaminated through its RePowering America's Lands initiative, which has so far received scant mention in the DRECP.

The agency also specifically calls out the draft plan for not paying enough attention to the DRECP's effect on desert watercourses such as the Amargosa River, suggests that the DRECP should examine whether large renewable energy installations in the plan area should be treated as large stationary sources of air pollution similar to coal-fired plants under the Clean Air Act, and urges that the final version of the plan remove a renewable energy development area from the Silurian Valley.

If you're wondering why the EPA would suggest regulating new "clean energy" facilities under the same air pollution standard as coal plants, you can sum up the reason in two words: particulate matter. About 516,000 acres of the draft DRECP's Development Focus Areas -- 806 square miles -- have soils that pose a significant risk of being eroded by wind if their vegetative or desert pavement covers are disturbed by construction.

That means adding a significant amount of particulate matter to the desert air whenever the wind blows, and that has significant effects on public health. In the words of the EPA's comments:

Inhalation of dust particles can lead to a number of respiratory problems, including asthma and Valley fever. Children, in particular, have greater sensitivities to various environmental contaminants, including air pollutants, as do the elderly and those with existing respiratory or cardiac disease.

Under the Clean Air Act, any new project that constitutes a potential new stationary source of air pollution must obtain a permit from the EPA under the agency's New Source Review program. Desert solar facilities have already been shown to contribute to particulate matter in the air downwind. Since the entire DRECP plan area violates federal clean air standards for particulate matter on a regular basis, it would seem sensible to apply New Source Review standards to those projects the DRECP is meant to encourage.

The EPA suggests that a procedure for determining whether new renewable projects in the plan area will need to obtain New Source Review permits be included in the DRECP's final Environmental Impact Statement: a substantial undertaking.

Yet another big request from the EPA centers on renewable energy development's often-literal impact on wildlife, especially birds. Wind turbines' threat to birds is well-documented, the agency points out, but the emerging risk to birds from solar facilities has only emerged since the DRECP team started putting the massive document together. The EPA offers straightforward suggestions as to how the risk to birds from renewables development in the desert should be addressed in the DRECP:

Include an updated discussion, in the [final EIS], devoted to the occurrence of avian mortality at utility scale solar sites, informed with the best available scientific research conducted on this topic.

Include, in the DRECP, a comprehensive monitoring protocol to catalog and analyze occurrences of avian mortality throughout the term of [incidental take permit] coverage.

Include provisions, in the DRECP, to potentially adapt, in response to monitoring and the recommendations of federal and state biologists, the siting or operation of renewable energy facilities to avoid or minimize impacts to avian species.

Given that agencies such as the BLM and the U.S. Fish and Wildlife Service are still working on mortality monitoring protocols for individual projects more than two years after the threats became a matter of public knowledge, drafting a broader protocol covering the DRECP's 22.5 million acres could conceivably delay the final plan by several years.

Perhaps most devastatingly, the EPA challenges the assumptions on which the DRECP framers' base their goal of siting 20,000 new megawatts of renewable energy generation within the plan area. EPA cites two main reasons for questioning those assumptions. The explosive growth in rooftop solar, along with improvements in power storage, make distributed generation more and more feasible as a way of meeting much of California's power habit, lessening the need for remote, utility-scale renewables in the desert. And what's more, says the EPA, most of the desert projects built to date have relied on federal loan guarantees and tax incentives that most likely won't be available in years to come.

In requesting that the DRECP's final EIS contain a full assessment of those factors and how they will affect the amount of power needed from the desert by the plan's target date of 2040, EPA is in essence backing the same Distributed Generation alternative offered by other critics of the DRECP. What's more, EPA is suggesting that the plan regularly update its projections for actual desert renewables demand, by including a recommendation that the final EIS...

[c]onduct such a re-evaluation on a regular basis, perhaps every two to five years, to account for changing market conditions and policies affecting the renewable energy industry in California.

Though they largely reflect criticisms that have been leveled at the DRECP by activists in past months, the EPA's comments will likely carry a bit more weight with the DRECP's authors. As a quasi-Cabinet-level agency outside the Department of the Interior, the EPA may not be as directly subject to the much-rumored Interior policy of squelching internal concerns over energy development in the California desert. And the agency's direct responsibility for maintaining the nation's air and water quality give its comments in those areas a bit more gravitas than similar comments coming from members of the general public.

If the state and federal agencies framing the DRECP take the EPA's comments as seriously as those comments merit, that will mean a significant amount of new work needs to be done before the plan is final. It would likely mean the document's authors will need to prepare a separate draft Supplemental Environmental Impact Statement to allow the public to comment on all the new material they'd have to generate to meet the EPA's requests.

And that could mean many months more delay in the DRECP, during which rooftop solar will likely just get cheaper and more abundant, making the DRECP all that much less necessary.