Winter Q&A

The High Pollution Advisory Program is an annual effort coordinated by the Air Pollution Control Division at the Colorado Department of Public Health and Environment. The primary goal is to reduce air pollution during the High Pollution Season (Nov.1 - March 31) through a combination of mandatory and voluntary efforts.

Color-coded advisories will be issued that either trigger mandatory residential burning restrictions in the seven-county metro Denver area or require no public action while promoting wise residential burning practices and vehicle use.

Red advisories activate mandatory residential burning restrictions throughout the Denver area. During red advisories, residential burning is limited to: a) approved devices; b) homes whose residents have obtained a waiver granting them permission to burn, or; c) residences that are located at or above 7,000 feet in elevation.

Red advisories are an indication that conditions exist under which the Denver area is in danger of exceeding state and federal health-based air pollutant or visibility standards. Regulators also encourage motorists to voluntarily reduce driving when red advisories are in effect.

Blue advisories do not require any action. Blue advisories are an indication that air pollutant and/or visibility readings are expected to remain within limits. However, motorists once again are urged to limit driving whenever possible and consider alternate modes of transportation.

The first advisory of the 2003-2004 High Pollution Season will be issued at 4 p.m. on Friday, October 31, 2003. The first advisory will take effect at midnight. All subsequent advisories will be issued at 4 p.m., take effect immediately, and remain in effect for the remaining 24 hours.

The program concludes with a 4 p.m. advisory issued on Monday, March 31, 2004, that will expire at midnight. Once again, advisories are in effect for 24 hours (4 p.m. to 4 p.m.) unless otherwise noted.

Yes. Air quality can be poor any day of the week. As a result, advisories will be called seven days a week, including holidays throughout the winter High Pollution Season.

The Colorado Department of Public Health and Environment dedicates a portion of its web site to the current air pollution advisory and a variety of informative air quality information. Learn more by visiting their web site at http://apcd.state.co.us/psi/advisory.html.

A 24-hour Air Quality Advisory telephone hotline (303-758-4848) is updated daily by 4 p.m. with the current advisory information. Current advisories also are included on the year-round Air Quality Bulletin telephone hotline (303-782-0211).

A large number of radio and television stations, along with local newspapers, will mention current advisories during weather and traffic reports, and station breaks. The Associated Press traditionally has included advisory information on the wire and the National Weather Service typically references the advisory on NOAA WeatherRadio.

As a matter of policy, advisories will not changed from blue to red unless an emergency situation arises that results in extremely poor air quality and a potential harmful effect on human health. This has not occurred during any previous season.

Occasionally, department meteorologists will issue a "split" advisory. This means an advisory is red until midnight and blue thereafter (midnight until 4 p.m.). Split advisories are rare, occurring only a handful of times each season at most. Only one split advisory has been issued during each of the last two seasons.

Wintertime temperature inversions trap colder air and pollution at ground level under a warmer layer of air. This is the most typical meteorological condition that leads to a red advisory. A variety of other meteorological conditions may lead to a red advisory.

The Colorado Department of Public Health and Environment expects to issue 50-70 red advisories during the season.

During the 2001-2002 High Pollution Season, actual advisory counts closely corresponded to the department's expectations with 100 blue advisories and 50 red advisories issued. One split advisory was issued.

WHO WILL BE AFFECTED BY MANDATORY RESIDENTIAL BURNING RESTRICTIONS DURING RED ADVISORIES?

Mandatory residential burning restrictions apply to everyone in the entire seven-county Denver-metro area residing below 7,000' elevation. There are exceptions for those who use EPA-certified or other approved devices. Another exception is granted to those who use a woodburning device as their sole source of heat. The restrictions are enforced either through local ordinances or the state regulation. Local ordinances supersede the state regulation in all areas where they exist if they are at least as restrictive as the state regulation. Consequently, local jurisdictions have enforcement authority and responsibility in more than 90 percent of the metro area. For more information, call the Air Pollution Control Division at 303-692-3281.

The state regulation (Colorado Regulation No. 4), adopted by the Colorado Air Quality Control Commission in May 1990 and revised in August 1992, applies to any community in the seven-county Denver metro area that did not have its own mandatory residential burning ordinance in effect on January 1, 1990. Under this regulation, the only exceptions to the residential burning restrictions are for people living above 7,000' elevation, those who use Colorado Phase III (Phase II EPA) certified woodburning stoves, Colorado approved pellet stoves, approved masonry heaters, or those whose stoves or fireplaces are their primary source of heat.

Local ordinances are in effect when red advisories are issued in municipalities that include: Arvada, Aurora, Boulder, Brighton, Broomfield, Denver, Englewood, Federal Heights, Glendale, Greenwood Village, Lafayette, Lakewood, Littleton, Longmont, Mountain View, Sheridan, Thornton, Westminster, and Wheat Ridge. In other areas within the seven-county area, the state's residential burning regulation applies.

No fuel of any kind can be burned in an unapproved device during a red advisory. The restrictions address the device being used, not the fuel. However, any type of fuel can be burned in a certified woodburning stove/fireplace (Colorado Phase III or EPA Phase II) or Colorado-approved pellet stove. It is best to think of a red day as restricting residential burning to approved devices only.

WHAT ARE THE STANDARDS FOR CARBON MONOXIDE, PARTICULATE MATTER AND VISIBILITY?

The carbon monoxide (CO) standard is 9 parts per million (9ppm) averaged over eight hours. A one-hour standard of 35ppm also exists.

Two particulate matter standards exist. The PM10 standard for particles 10 microns in size or less is 150 micrograms per cubic meter (150Fg/m³) averaged over 24 hours. The PM2.5 standard for particles 2.5 microns in size or less is 65 micrograms per cubic meter (65Fg/m³) averaged over 24 hours.

The visibility standard is .076 per kilometer of atmospheric extinction, which means that 7.6 percent of the light in a kilometer of air is blocked. The level must exceed the standard based on a four-hour average for a violation to occur. The standard applies only during the core daylight hours from 8 a.m. - 4 p.m. when the relative humidity is less than 70 percent. Four-hour exceedance periods cannot overlap, which allows for a maximum of two exceedances per day.

Yes. Often, however, the conditions that cause poor visibility also will cause a buildup of carbon monoxide and/or particulate matter in the ambient air.

Two scales are used. The Air Quality Index (AQI) and the Visibility Standard Index (VSI) reflect actual air quality conditions. A calculation is applied to readings for carbon monoxide, particulate matter, and visibility that converts those readings to the following scales:

AQI Category	AQI Range
Good	0-50
Moderate	51-100
(- - - - - - - - - - - - - Health standard - - - - - - - - - - - - )
Unhealthy for Sensitive Groups	101-150
Unhealthy	151-200
Very Unhealthy	201-300
Hazardous	301-above

VSI Category	VSI Range
Good	0-50
Moderate	51-100
(- - - - - - - - - - - - Visibility standard - - - - - - - - - - - )
Poor	101-200
Extremely Poor	201-above

AQI and VSI levels are included on both the Air Quality Advisory Hotline (303-758-4848) and the Air Quality Bulletin Hotline (303-782-0211). All red or blue advisories issued to local media contain current AQI and VSI readings, and high readings for that day.

IS IT REALLY THAT IMPORTANT FOR PEOPLE TO TRY TO LIMIT THEIR DRIVING AS PART OF THE CLEAN AIR EFFORT?

Yes. Driving significantly contributes to all three air pollution problems. Typically, motor vehicle use contributes 80 to 90 percent of the carbon monoxide problem in the Denver metro area, more than 60 percent of the particulate matter problem (road dust, tailpipe emissions, and street sanding), and approximately 30 percent of the visibility problem can be attributed to motor vehicle use. A driving reduction is essential if we are to improve air quality.

Traditional methods of limiting driving like carpooling, riding the bus or light rail, and combining trips remain viable alternatives. There are some other strategies that clean up the air, like telecommuting, teleconferencing, and shopping by computer. These and other innovative ways to cut back on driving reduce pollution while often saving time and money.

Employers can take advantage of programs offered by RTD and the Denver Regional Council of Governments. RTD's Eco Pass Program includes a guaranteed ride home component. This gives employers a cost-effective way to provide employees a year-round, tax-free, unlimited ride on RTD. The Denver Regional Council of Governments' Guaranteed Ride Home Program allows employees to take a free cab if unexpected circumstances require transportation when people have left their car at home.

I WOULD LIKE TO LIMIT MY DRIVING, BUT I REALLY CAN'T BECAUSE OF MY JOB. IS THERE ANYTHING ELSE I CAN DO?

Yes. Perhaps the most important thing you can do if limiting your driving does not appear to be an option is to make sure the vehicle you drive is well-maintained. A well-maintained vehicle pollutes a lot less than a poorly-maintained one. Additionally, well-maintained vehicles can put money in your wallet. Proper maintenance generally means better fuel economy and can help avoid a major costly repair down the road. If you must drive, maintain your vehicle according to the manufacturer=s recommendations.