Air Pollution Trends in Denver:
“You’ve Come a Long Way, Baby”
Gregg Thomas
Manager of Air, Water, and Climate Section
Nov 2013
Overview
• Most pollutants down significantly
over the last 10-20 years
• Public perception slowly improving
• Ozone continues to be a problem
• Oil and gas development presents
challenges regionally
• Local challenges around odors and
highway expansion
National Citizen Survey
Carbon Monoxide
Carbon Monoxide 8-Hr Trends Downtown
30
Concentration (ppm)
25
20
15
10
National Ambient Air Quality Standard = 9 ppm
5
0
1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011
Lead
Sulfur Dioxide
Annual means have declined from 18 ppb in 1980 to 2 ppb in 2012
Nitrogen Dioxide
Annual means > 2x higher than Houston;
New 1-hr near road standard (100 ppb) starts 2014; will be challenging
200
180
160
140
120
100
80
60
40
20
0
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Concentration (micrograms per m3)
Particulate Matter <10 Microns
PM10 24hr 2nd Max Downtown
NAAQS = 150 micrograms
Fine Particulate Matter <2.5 microns
Fine Particulate Matter (PM2.5) Trends in
Metro Denver 1999-2012
15
Old Annual average PM2.5 standard = 15 micrograms per cubic meter
New Annual average PM2.5 standard = 12 micrograms per cubic meter
Concentration
12
9
6
3
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Downtown Denver
Commerce City
Boulder
Swansea
Volatile Organic Compounds (VOCs)
Volatile Organic Compounds (VOCs)
Ozone Trends
Rolling 3 Year 8-hr Avg Ozone Trends in Metro
Denver 1997-2013
Ozone Concentration (ppb)
90
85
80
75
Current standard: 75 ppb
70
65
60
55
Rocky Flats
Commerce City
Chatf ield State Park
NREL
Ozone – What’s Ahead?
• Ozone NAAQS due to be updated late
2014
• It may be revised to 70 ppb or lower
from 75 ppb
• On the books strategies should help,
but 75 ppb appearing difficult
• New oil and gas VOC regulations in
Feb 2014 should help (CDPHE)
I-70 East Expansion
Odors – the 800 Pound Gorilla
•
•
•
•
We know the main sources of odor complaints
Even stinkiest odors in Denver do not violate
Existing air pollution data are of minor value
While we may know the sources, identifying
the odorous compounds is difficult
• Exploring innovative grants to understand this
problem with non-profits and health
researchers
• Has community support, needs organization
Summary
• Significant progress in reducing most air
pollutants
• Ozone remains a problem
• Progress on I-70 (11 yrs later…)
• Raising a stink on odors