Emissions: The Rise of Retroprofits

Construction companies and equipment manufacturers beware! If California lives up to its tradition as the nation's bellwether of regulatory trends, you're about to feel a lot more pressure to reduce the emissions from equipment already in the field.

This spring, the California Air Resources Board (CARB) is set to consider new emission regulations for "in-use" off-highway equipment that are likely to require mandated retrofits or early retirement for some construction equipment. The regulations will be based on CARB's 1998 decision to label the particulate emissions in diesel exhaust as a toxic air contaminant, a move that allowed it to bypass federal restrictions on states' ability to regulate emissions on farm and construction equipment.

Since then, other states — and the federal government, as well — have labeled diesel exhaust, or some of its many components, as air contaminants, allowing them to pass regulations on equipment currently being used.

State regulators believe they have no choice but to go after existing equipment if they are to meet the stringent air quality standards imposed on them by the federal government.

They have to come up with formalized plans to meet federal air quality standards for ozone by this summer. In addition, they must develop similar plans to reduce particulate emissions by next spring.

Off-highway equipment is especially vulnerable because it accounts for an estimated 75% of all particulate emissions. With the introduction of clean-diesel engines and low-sulfur fuel, federal regulators have reached the threshold of achievable emission reductions from new equipment. The only place to achieve additional reductions is by targeting existing equipment.

A bleak assessment

In a new report (again from California), the Union of Concerned Scientists claims emissions from construction equipment is causing 1,100 premature deaths, 1,000 hospital admissions, 2,500 cases of acute asthma and tens of thousands of asthma attacks and other lung problems.

Digging up Trouble: The Health Risks of Construction Pollution in California, released in December of 2006, recognizes that the Tier 4 regulations that will be phased-in starting in 2011 will go a long way to reducing particulate emissions, but concludes that "the full benefits will not be realized until sometime after 2030, when the long-lasting equipment currently in use today has finally been retired."

The report notes that five types of construction equipment — excavators, tractors/loaders/backhoes, bulldozers, rubber-tired loaders and skid-steer loaders — account for 65% of particulate emissions and 60% of NOx emissions. It also notes that an excavator operating for one hour will emit as much particulates as an on-highway truck driven for 1,100 miles (see chart).

This bleak assessment is based on a somewhat skewed comparison. Off-highway emissions were based on an average of all existing equipment, regardless of age, using standard, high-sulfur fuel. Estimated emissions from on-highway trucks, on the other hand, were based on 2007 clean-diesel engines using ultra-low-sulfur fuel. Unfortunately for off-highway equipment manufacturers, this important distinction will likely be glossed over in any public debate.

While construction equipment may be a juicy regulatory target, achieving emission reductions could prove both challenging and costly. The Diesel Technology Forum, an organization that promotes diesel technology, says converting to ultra-low sulfur diesel could lower particulate emissions by 10% alone, without any equipment or engine changes. However, the ultra-low-sulfur fuel needed to achieve that won't be required for off-highway equipment until 2010, although it is available now.

How to achieve emission reductions?