EPA v. MBTA COMMUTER RAIL

Case summary

On March 16, 2026, Region 1 entered into a Clean Air Act administrative order on consent requiring the Massachusetts Bay Transportation Authority ( MBTA ) and its commuter rail operator Keolis Commuter Services, LLC ( Keolis ) to both improve the reporting of and reduce locomotive idling at train layover facilities in the Greater Boston area. The order follows up on the Region's October 2025 Notice of Violation that found the two entities had violated federally-enforceable locomotive idling limits contained in the Massachusetts state implementation plan. The March 2026 administrative order specifically requires MBTA and Keolis to assess their reporting of locomotive idling, submit a data-quality assurance plan for EPA's review, produce a comprehensive idling control plan identifying specific corrective measures to implement, and submit quarterly progress reports. EPA previously brought an enforcement action against MBTA and its former commuter rail operator that resulted in a 2010 Consent Decree addressing locomotive idling. Both the order and preceding notice of violation were shared with the Massachusetts Department of Environmental Protection.

Defendants (2)

• Keolis Commuter Services, LLCNamed in complaintNamed in settlement
• Massachusetts Bay Transportation AuthorityNamed in complaintNamed in settlement

Facilities (6)

• MBTA WIDETT CIRCLE COMMUTER RAIL SERVICE AND INSPECTION FACILITY

  110 WIDETT CIRCLE, BOSTON, MA, 02118

  Registry ID: 110071722331

• MBTA NEWBURYPORT LAYOVER FACILITY

  9 NEWBURYPORT TPKE, NEWBURY, MA, 01951

  Registry ID: 110071724076

• MBTA COMMUTER RAIL MAINTENANCE FACILITY

  70 REAR THIRD AVENUE, SOMERVILLE, CITY OF, MA, 021430000

  Registry ID: 110071722252

• MBTA NEWBURYPORT LAYOVER FACILITY

  9 NEWBURYPORT TPKE, NEWBURY, MA, 01951

  Registry ID: 110071724076

• MBTA READVILLE MAINTENANCE FACILITY

  41R WOLCOTT CT, BOSTON, MA, 02136

  Registry ID: 110063251617

• ROCKPORT LAYOVER FACILITY

  5 STATION SQ, ROCKPORT, MA, 01966

  Registry ID: 110071722223

Statutes cited

• CAA 110 — Implementation Plan for National Primary and Secondary Ambient Air Quality Standards

Enforcement conclusions (1)

• MBTA COMMUTER RAILentered 2026-03-16

  Primary law: CAA

Timeline (3 milestones)

• 2026-03-16Final Order Issued
• 2026-03-16Complaint Filed/Proposed Order
• 2026-03-18Enforcement Action Data Entered