New Jersey and Virginia are on track to join the Northeast’s carbon trading program in 2020, with final rules expected to be released later this year and adopted in 2019.

Both states are in discussions with the Regional Greenhouse Gas Initiative on the details of linking up with the nine-state cap-and-trade program, state environmental regulators said Sept. 6 at a conference.

Chris Bast, deputy director of the Virginia Department of Environmental Quality, said RGGI is like an interstate...