The first year of Donald Trump’s presidency has seen radical shifts in a number of different policy areas, including trade and foreign policy. With respect to rolling back the overreaches of the regulatory state, the administration has perhaps made the most progress in terms of its environmental policy. On Tuesday, Environmental Protection Agency (EPA) Administrator Scott Pruitt will testify before a Senate committee about the changes under the new leaner, pro-industry EPA that he leads. Under Pruitt, the EPA has changed in its size, its regulatory relationship with states, and its approach to regulation, which has ruffled the feathers of environmentalists and encouraged growth in several industries.

Trump’s appointment of Pruitt, the former attorney general of Oklahoma, marked a different approach to environmental policy. As attorney general, Pruitt had frequently clashed with the Obama-era EPA. As head of the agency, he advocated an approach that stressed the rule of law, increased state enforcement authority, and a more pro-business approach to regulation.

Pruitt’s tenure as head of the EPA has been polarizing. For environmentalists and many on the left, his tenure has signaled a push towards pro-fossil fuel policies alongside the weakening of enforcement measures relating to carbon dioxide and other emissions. At the same time, industries including oil, natural gas, and coal have seen growth unlike that of the preceding administration.

Under Pruitt’s leadership, the EPA switched away from being penalty-focused and towards an enforcement-minded approached to environmental regulation. Overall, this showed a switch towards the mindset that energy projects should be approved unless specific evidence showed that they demonstrated a harm to the environment. Practically speaking, this meant that the EPA concentrated more on finding ways for projects to proceed rather than seeking to shutter them with violations and fines.

Along with other regulatory changes by the administration, this led to an increase in investment in the United States. The Trump administration approved both the Dakota Access and Keystone pipelines, and Pruitt’s EPA announced industry-friendly changes to the Clean Air and Clean Water Acts. Although adjusting to lower oil prices, the fracking boom continued, keeping oil and natural gas prices low for American consumers. Also, companies explored energy development in places like Alaska, which had been ignored in recent years because of high transport costs. Most recently, Exxon announced a new plan to invest $50 billion in the U.S. over the next five years. In its announcement, the company cited recent changes in tax policy and regulatory structure as reasons behind its decision.

At the same time, the size of the EPA also decreased. Although the agency wrestled with budget negotiations, in the end, finances had little to do with decreases in staff size. More than 700 people have left the agency since Pruitt took office, many of them taking early retirement, citing concerns about the direction in which the agency is heading. This leaves the EPA roughly the size it was when Reagan was president.

Pruitt’s approach relies on a different partnership with states. As the head of the EPA, he stressed that state and federal environmental officials will strive to work in tandem, rather than legislating the same issues. This means that the EPA will work towards approval, rather than finding ways to fine states for violations.

One early sign of this change in approach was how the agency handled a backlog of chemical approvals. When Pruitt took office, the EPA faced a backlog of some 600 chemicals that needed its approval. Pruitt made clearing the backlog a focus of the agency over the summer and also announced changes to the chemical regulatory process that would streamline approval in the future.

Another of Pruitt’s focuses was Superfund sites. From the beginning of his tenure, Pruitt stressed that it was unacceptable for sites to remain on the list for decades at a time without progress being made for their cleanup. He enacted a procedure last spring to prioritize the clean up of sites with estimated clean up costs of $50 million or more. After a year, seven sites have been removed from the Superfund list, up from two in 2016. While a step in the right direction, removal of the sites makes only a slight dent in the overall list, which includes around 1,300 entries.

Senate Democrats are planning to grill Pruitt over what they see as a pattern of willful neglect and a lack of regulatory enforcement at the agency. Last week, Senate Democrats led by Sen. Ed Markey, chairman of the Senate Climate Action Task Force, questioned a panel of three witnesses looking for examples of wrongdoing that they could use when questioning Pruitt.

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