California is always on the cutting edge of environmental regulations, so it's no surprise that several of its air quality management districts have recently mandated lower nitrous oxide (NOx) emissions for large boilers.

The reason for the new regulations is that NOx is a precursor to ozone, and several areas in the state have not improved their ground-level ozone quality as quickly as the federal government requires. According to the EPA, inhaling ground-level ozone can result in health effects in broad segments of the population, including respiratory symptoms (e.g., coughing, throat irritation, shortness of breath), reduced lung function, and airway inflammation.

EPA's previous 1-hr ozone standard stated that the ozone threshold value needed to be 0.12 parts per million (ppm), measured as 1-hr average concentration. An area would meet the ozone National Ambient Air Quality Standards (NAAQS) if there were no more than one day per year when the highest hourly value exceeded the threshold. To be in attainment, an area had to meet the ozone NAAQS for three consecutive years.

That rule gave way to EPA's 8-hr ozone implementation rule, published in 2004, which lowered the standard for ambient ozone from 0.12 ppm of ozone averaged over one hour to 0.08 ppm of ozone averaged over eight hours. The new rule consists of two different nonattainment scenarios. Areas with more serious ozone pollution are subject to more prescribed requirements and are given longer to attain the standard. The requirements are designed to bring areas into attainment by their specified attainment dates.

San Joaquin Valley and Sacramento are two areas in California that needed to be brought into attainment, which is why both have recently issued new, lower emissions regulations for large boilers.

Sutter Memorial Hospital will require a new boiler by 2007, while Sutter General Hospital will need two new boilers by 2008, in order to meet Sacramento's new boiler emission rules. The hospitals' boilers range from 12 to 17 MMBtuh and are used for everything from heating to cooking to sterile processing.

Clearing the valley air

California offers some of the most amazing natural (sequoias, redwoods) and manmade (Disneyland, Hollywood) attractions in the country. And, according to the American Lung Association (ALA), the heavily populated state also hosts some of the most serious air pollution problems in the nation.

According to the organization's 2005 "State of the Air" report, California cities and counties continue to dominate the list of places with the highest number of days of high air pollution. One of those areas is San Joaquin Valley, which received an ozone grade of "D" from the ALA and a 24-hr particle pollution grade of "F."

The San Joaquin Valley Air Basin (SJVAB) is classified as an extreme ozone nonattainment area for the 1-hr ozone standard and is currently classified as a serious nonattainment area for both the new 8-hr ozone and the current particulate matter (PM10) health-based NAAQS, established by the federal Clean Air Act. The SJVAB is also classified as a severe nonattainment area for the California ozone standard and nonattainment for the California PM10 standard.

Given their numerous nonattainment positions, SJVAB had to do something to address air quality issues, so the San Joaquin Valley Unified Air Pollution Control District decided to amend its existing Rule 4306, as well as add new boiler emission rules. Rule 4306, which was adopted in 2003, is applicable to new and existing boilers, steam generators, and process heaters with a total rated heat input of greater than 5 MMBtuh.

Under Rule 4306, boiler emissions are reduced significantly, said Maria Stobbe, planning manager of the San Joaquin Valley Pollution Control District. "If a unit is smaller than 20 million Btuh, the NOx limits have been brought down from 30 ppm to 15 ppm. If the units are larger than 20 million Btuh, those limits are now 9 ppm for most of the units, with a small subset at 6 ppm."

The revised Rule 4306 will result in emission reductions of over two-thirds of their former levels, said Stobbe. Due to the number of units involved, the compliance period stretches from June 1, 2005 to December 1, 2008. There are some exemptions, including one that applies to facilities that have low fuel usage.

Compliance options include retrofitting the units with new burners, adding emission controls to the exhaust stack, or shutting down the unit. The cost to comply varies, depending on the size and number of units operated, said Stobbe. "For the larger units, annual compliance costs per unit range from $11,250 to $28,750." District inspectors from the Compliance Division visit facilities once a year to make sure the boilers conform to the new rules.

In addition to Rule 4306, the District adopted two other boiler emissions regulations in 2005 to control emissions from previously permit-exempt units. Rule 4307 applies to units rated between 2 and 5 MMBtuh and requires existing units to be replaced with certified units by January 1, 2009. Rule 4308 applies to units rated between 75,000 and 2 MMBtuh and is an attrition rule, requiring new or replacement units to meet specified standards when the old units are being replaced through natural attrition.

The changes may not stop with these tighter boiler emission rules. According to Stobbe, the District is currently assessing the boiler rules as part of the development of the District's 8-hr ozone plan development process. "We will determine if there may be additional emission reductions to be achieved by imposing more stringent emission limits that could be technologically and cost effectively achieved with more advanced state-of-the-art NOx control techniques."

North to Sacramento

According to ALA, Sacramento fared even more poorly in its 2005 State of the Air report than San Joaquin Valley. Based on the organization's research, Sacramento received an "F" for ozone and 24-hr particle pollution. The Sacramento region is designated as a serious non-attainment area for the federal 8-hr ozone standard with an attainment deadline of June 2013.

To help meet that deadline, the Sacramento Metropolitan Air Quality Management District (SMAQMD) revised its Rule 411 last October. The rule applies to NOx emissions from gaseous and non-gaseous boilers, process heaters, and steam generators with a rated heat input capacity of 1 MMBtuh or greater.

Basically, the rule states that boilers with capacities ranging from 1 to 5 MMBtuh must have NOx emissions of less than 30 ppm, while boilers with capacities greater than or equal to 5 MMBtuh and less than or equal to 20 MMBtuh must have NOx emissions of less than 15 ppm.

Like San Joaquin Valley's Rule 4306, an exemption is in place for those facilities that do not use much fuel. If facilities take the low-fuel usage exemption, they must apply for it by October 2006. By October 2007, facilities must have at least one boiler that is in compliance with the new rule. If a facility has multiple units, then they may have until October 2009 to retrofit or replace their existing boilers to meet the new guidelines.

Aleta Kennard, air district technical services program supervisor for SMAQMD, estimated that approximately 71 units in the Sacramento area would be affected by the new rule. "For the 1 to 5 million Btuh boilers, there were already about 74 boilers in the district that met the limits, so the rule will only require an additional 35 to be retrofitted in that size range. For units greater than 5 million Btuh, there are about another 36 units in that size range that have to make a change."

Sutter General and Sutter Memorial hospitals will both need to make some changes in order to comply with the new rule, said Tony Burg, assistant administrator, Sutter Medical Center, Sacramento. "We currently have six boilers, three in each hospital, and they range in size from 12 to 17 million Btuh. Out of those six, three are compliant right now, which leaves us three that are out of compliance. We plan to retrofit the remaining three boilers, as opposed to replacing them, and those retrofits will range from $100,000 to $160,000 for each boiler."

While it's never a good time to come up with funds to replace or retrofit mechanical equipment, Burg noted that the extended compliance timeframe will be helpful. That timeframe was a result of community input, said Kennard, noting that SMAQMD did a lot of outreach when amending Rule 411. "We did a lot of workshops, one-on-one meetings, and outreach to the specific sources that were affected."

That initial outreach resulted in sources expressing concern about the compliance timeframes, multiple units, and certain types of boilers that may have a little higher ppm limit due to the inability to find compliant burners. "Initially we recommended a one-year compliance time frame, but we bumped it back two years for everybody, so they could work it into their budgets," said Kennard. "Then if they had multiple units we extended it even further to help with budgets."

The result is a rule that most people can live with, noted Rick Balazs, senior environmental consultant with the Sacramento Business Environmental Resource Center in Sacramento. "With this rule, SMAQMD probably did one of the most intensive internal reviews and then subsequent public outreaches that I've ever seen. I have to take my hat off to them in that regard. I think the Air District is really hitting their target in that they're looking for the large, gross polluter types, and they're not just trying to go across the board and hammer everybody that runs the boiler for a short amount of time."

Balazs's job involves helping facilities comply with all kinds of different environmental laws, and he said that as a result of the SMAQMD's outreach, he's had very few calls regarding Rule 411. "Most of the people who are calling are not exactly sure how the low fuel exemption works, so we're working with them to calculate their gas usage. Otherwise, it's been pretty simple so far."

For those who do not qualify for the low fuel exemption, often the most cost-effective way of complying with the law is replacing the burner. Kennard noted that the cost of a retrofit or replacement could range from an annualized cost of about $4,000 to an annualized cost of $54,000, depending on the source.

As far as the future is concerned, SMAQMD will soon start looking at other regulations. "We will be looking at the in-between size of 75,000 to 1 million Btuh that we don't have a limit for right now," said Kennard. "But that will be point of sale and new kinds of requirements. Right now, we're working on our control measures for our 8-hour ozone state implementation plan."

All of these measures will hopefully help clear the air out of the most troublesome areas in California. As Burg noted, "Air quality is everyone's concern, and every organization and every business that contributes to that certainly has an ownership in being as responsible as they can. We strive to be a good neighbor, and complying with this new rule is simply a part of doing that."