The Environmental Protection Agency on Thursday announced a proposal to tighten oil refinery emission standards for the first time in nearly two decades.

Environmentalists hailed the proposed changes as a first step toward reducing rates of cancer and other diseases in “fenceline communities,” the often-impoverished neighborhoods that abut refineries.

“The rules look pretty strong, but it’s a solution that’s long overdue,” said James Goodwin, senior analyst at the Center for Progressive Reform. “It was pushed back and pushed back. Every day [the changes] were delayed, more and more people are getting sick.”

The proposal is part of a consent decree that resolved a lawsuit filed by attorneys with nonprofit organizations Earthjustice and the Environmental Integrity Project on behalf of Americans directly affected by oil refinery emissions in Louisiana, Texas and California.

The changes would compel operators to monitor benzene emissions, upgrade storage tank emission controls, ensure waste gases are properly destroyed and adopt new emission standards for certain kinds of oil heating units. Operators would also have to make public the results of emissions monitoring.

"The common-sense steps we are proposing will protect the health of families who live near refineries and will provide them with important information about the quality of the air they breathe," EPA administrator Gina McCarthy said in a statement.

Oil refineries have been repeatedly accused of underreporting accidents that cause emissions of toxic substances, and of underreporting the emissions they release in the course of normal operations. The EPA’s two-decade-old regulations did not require that refineries monitor their emissions at the fencelines of their plants, leading activists to charge that plants were allowed to pollute their surrounding communities without running afoul of the law.

A suit filed in 2012 in district court accused the EPA of shirking its duties under the Clean Air Act by neglecting to review and possibly revise refinery emission standards every three years. The EPA has not implemented new emission standards since 1995. The suit also said that mainly low-income and minority people share fencelines with refineries, and are therefore at disproportionate risk of illnesses related to air quality.

Environmental groups claim that some 150 petroleum refineries nationwide annually emit more than 20,000 tons of hazardous air pollutants, including chemicals such as benzene and toluene, which are linked to cancer.

Environmentalists say these rules will likely reduce those emissions, but not completely eliminate them. They said the EPA could have gone a step further in its monitoring requirements – but as of now it looks like the agency will only require “passive” monitoring, which takes samples at pre-scheduled intervals and can therefore miss important spikes in releases.

Nevertheless, environmentalists said that the rules were a very good first step toward what they want to see implemented at U.S. oil refineries.

“The monitoring can obviously be improved, but we are just so happy to see monitoring of a requirement in the rule, period,” said Anna Hrybyk, a program manager at air monitoring group Louisiana Bucket Brigade.

The American Petroleum Institute, which lobbies for oil refineries, called the proposed regulations unnecessary.

“With this proposal, EPA adds to the list of new regulations impacting refineries that come with enormous costs but questionable environmental benefits,” it said in a news release.

The EPA will accept comments on the proposal for 60 days. It also plans to hold two public hearings near Houston and Los Angeles, and will finalize the standards in April 2015, though some expect that date to be pushed back.

With wire services