Thanks to the 2010 federal requirement of ultra-low sulfur diesel fuel and new Tier 4 emissions standards by the EPA, particulate emissions from non-road diesel engines, including agricultural and construction equipment, have been reduced by 99%.
The Tier 4 emission standards [PDF] also target smog-producing nitrogen oxide, with new engines producing 99% less emissions than1996 engines. With new EPA standards already in place for trucks and buses, non-road diesel engines at "farms, construction sites and utilities" were the next target, writes Brian Bienkowski of Environmental Health News.
“It’s been a real challenge getting to this point,” said Allen Schaeffer, executive director of the Diesel Technology Forum, which represents engine manufacturers. “But all of this work has virtually eliminated nitrogen oxide and particulate matter from diesel engines.”
The rule called for a reduction of 90% over the 1996 models, but Schaeffer indicated that engine manufacturers met the higher target. However, non-road diesel engines still emit more than new buses and trucks due to the complexity of the various equipment types. "They are allowed to emit about 50 percent more grams of particles and nitrogen oxides per kilowatt-hour."
A variety of new technologies are producing cleaner farm and construction machines. Included are lower-sulfur diesel fuel, particle-trapping filters and more efficient engines with fuel-injection software, recirculated exhaust systems or catalysts that prevent pollutants from forming.
The public is the big winner with the new engine and fuel standards, as particle pollution is inked to heart attacks and respiratory disease.
"The foundation for lower emissions is ultra-low sulfur diesel fuel. In 2010 the allowable level of sulfur in diesel fuel dropped to 15 parts per million from 2007’s 500 parts per million," writes Bienkowski. Ahead of the game, as usual (due to having the nation's worst air quality though), was California, introducing the cleaner fuel as early as 2006 as we noted then.
FULL STORY: Dirty for decades, diesel tractors, bulldozers get cleaned up

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

Chicago’s Ghost Rails
Just beneath the surface of the modern city lie the remnants of its expansive early 20th-century streetcar system.

Amtrak Cutting Jobs, Funding to High-Speed Rail
The agency plans to cut 10 percent of its workforce and has confirmed it will not fund new high-speed rail projects.

Ohio Forces Data Centers to Prepay for Power
Utilities are calling on states to hold data center operators responsible for new energy demands to prevent leaving consumers on the hook for their bills.

MARTA CEO Steps Down Amid Citizenship Concerns
MARTA’s board announced Thursday that its chief, who is from Canada, is resigning due to questions about his immigration status.

Silicon Valley ‘Bike Superhighway’ Awarded $14M State Grant
A Caltrans grant brings the 10-mile Central Bikeway project connecting Santa Clara and East San Jose closer to fruition.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
Caltrans
City of Fort Worth
Mpact (founded as Rail~Volution)
City of Camden Redevelopment Agency
City of Astoria
City of Portland
City of Laramie