With financial support from a not-for-profit environmental group,Amtrak is upgrading its diesel locomotives to reduce hours of idling time around the Rensselaer station and repair facility after air tests by a citizens group found unsafe levels of diesel emissions.

Seven locomotives already have been retrofitted to connect to ground power at the repair shop, conserving fuel and reducing emissions, with a total of 18 locomotives expected to be modified by September, said Amtrak spokesman Craig Schulz on Tuesday. This will allow trains to be powered without having to operate the diesel engines for hours at a time.

That equipment is being paid for with about $90,000 from the Hudson-Mohawk Group of the Sierra Club, said group Chairman Pete Sheehan. That money is part of a $250,000 grant for air quality issues that the group got from the owners of a nearby natural gas-fired power plant as part of the plant’s state approval.

Additionally, Amtrak will be adding electrification to the rails at the passenger terminal, so waiting trains there can be powered without the engines having to idle. That work should be done by the end of next year.

“We see this as money well spent,” said Sheehan. “It will result in a direct reduction in diesel emissions in that neighborhood. That is what we are most concerned about, as there are a number of people there with various health ailments related to poor air quality.”

He said the upgrades will reduce idling by an average of two hours daily for each locomotive. His group, with the help of a community organization, Concerned Citizens of Rensselaer, had conducted private air quality tests that showed unsafe levels of diesel emissions around the Amtrak facility.

“We are very pleased that EPA took those results and saw there was a problem,” said Sheehan. “We will continue to be engaging on air quality in Rensselaer, as we have not spent all of our grant.”

On Thursday, U.S. Environmental Protection Agency Regional Administrator Judith Enck will speak at a public meeting on the upgrades. “The money from the Sierra Club was a catalyst to get this to happen,” she said. “There will be an important reduction in emissions. This will be like running a giant extension cord to the trains while they are being worked on and being cleaned.”

That meeting is set for 7 p.m. at Rensselaer Junior/Senior High School, 25 Van Rensselaer Drive.

Michele Peart, a member of Concerned Citizens of Rensselaer and an 18-year resident of South Street, said the community organization and the Hudson-Mohawk Group conducted air tests on Broadway around the station and released the results to EPA in 2013.

Those tests found high readings of elemental carbon, a byproduct of diesel combustion that could put people nearby at elevated risk of cardiovascular and respiratory problems after just a day.

Trains there can idle at the station and repair yard for hours. Last year, the citizens group and Sierra Club called the air quality results “alarming.”

Peart said Enck visited the facility later and saw five trains idling at the same time.

In March 2013, EPA announced that Amtrak would install equipment aimed at reducing the amount of times that trains are at idle.

Diesel exhaust is classified as a potential human carcinogen by EPA and the International Agency for Research on Cancer, according to the Union of Concerned Scientists.

Studies of humans routinely exposed to diesel fumes indicate a greater risk of lung cancer. For example, occupational health studies of railroad, dock, trucking and bus garage workers exposed to high levels of diesel exhaust over many years showed an increased risk of lung cancer of up to 50 percent, according to the Union of Concerned Scientists.

The local Rensselaer and environmental group paid for nearly two dozen professional air sampling tests with part of a $250,000 grant that was provided by Empire Generating Co., owners of a natural gas electricity plant near the Port of Rensselaer.