America’s job creators are asking for more time to comply with an expensive new EPA rule that could threaten electricity reliability and hurt businesses of all sizes.

Under the so-called Utility MACT standard, coal-fired and oil-fired power plants would have to limit their emissions of mercury, arsenic, chromium, hydrochloric acid and several other toxic substances. The final rule, which the EPA is due to publish on Dec. 16, would require the plants to use “maximum achievable control technology” to control the pollutants. Offending plants would have three years to get their emissions in line with the new standards, and the EPA can grant individual plants a fourth year if special circumstances arise.

However, some utilities will need additional time to comply, according to a multi-industry letter sent to the president on December 9. “Utilities must replace power plants, install compliance equipment, and build new natural gas pipelines and transmission lines. This is going to cost tens of billions of dollars and require a reasonable number of years for a smooth transition to a cleaner generating fleet. If the final rule fails to recognize these realities, our entire economy will suffer,” the letter warns.

The letter goes on to say, ““We believe the goals of protecting public health and the environment and maintaining a reliable electric system can both be met through an orderly and realistic transition period under the Utility MACT rule. Achieving these goals will require your presidential leadership, and we urge you to act.” The letter was signed by 135 groups, including utility companies, local chambers of commerce, and national trade associations.

The American Coalition for Clean Coal Electricity estimates that consumers will pay more than $120 billion in higher electricity costs and $50 billion more in natural gas prices over the next 10 years under the new rule.

In addition, reliability of power could be seriously compromised. The organizations responsible for the reliability of the electric grid—including the North American Electric Reliability Corporation and regional transmission organizations—have expressed serious concerns about the impact of the Utility MACT rule as electric utilities replace power plants and install controls on others during a short time period. Members of the Federal Energy Regulatory Commission (FERC), which is ultimately responsible for grid reliability, stated as recently as November 30, that utilities should not be forced to choose between reliable electric service and meeting environmental requirements.

In an effort to educate policymakers on the potential impacts of the new rule, the U.S. Chamber is running a series of national television ads and print ads inside the Beltway. The print ads, titled “Don’t Let the EPA Turn the Lights Out on America,” show a dark town with no street lights. The ads urge Americans to contact President Obama and tell him, “America needs more time to get the job done right, not more lost jobs.”