WASHINGTON — The Environmental Protection Agency announced a series of enforcement actions Wednesday to address air pollution, unsafe drinking water and other problems afflicting minority communities in three Gulf Coast states, following a “Journey to Justice” tour by Administrator Michael Regan last fall.

The agency will conduct unannounced inspections of chemical plants, refineries and other industrial sites suspected of polluting air and water and causing health problems to nearby residents, Regan said.

And it will install air monitoring equipment in Louisiana’s “chemical corridor” to enhance enforcement at chemical and plastics plants between New Orleans and Baton Rouge. The region contains several hotspots where cancer risks are far above national levels.

The EPA also issued a notice to the city of Jackson, Mississippi, saying its aging and overwhelmed drinking water system violates the federal Safe Drinking Water Act. The order directs the city to outline a plan to “correct the significant deficiencies identified” in an EPA report within 45 days.

In separate letters, Regan urged city and state officials to use nearly $79 million in funding allocated to Mississippi under the bipartisan infrastructure law “to solve some of the most dire water needs in Jackson and other areas of need across Mississippi.’’

The actions were among more than a dozen steps announced being taken in response to Regan’s tour last November.

A Toxics Release Inventory prepared by the EPA shows that African Americans and other minority groups make up 56% of those living near toxic sites such as refineries, landfills and chemical plants.

Negative effects include chronic health problems such as asthma, diabetes and hypertension.

Inspections currently are done on a schedule or with advance notice, Regan said, but that is about to change. “We are amping up our aggressiveness to utilize a tool that’s in our toolbox that ... has been there for quite some time,’’ he said.