NOx Emissions Impacts from Widespread Deployment of CHP in ...

NOx Emissions Report
as “moderate” in the same category as 21 other urban areas. Recently, the Texas
Commission on Environmental Quality (TCEQ) requested and EPA approved a
reclassification of the HGB area from “moderate” to “severe” nonattainment, pushing
back the area’s attainment deadline from 2010 to 2019.
Due to Houston’s industrial mix and climatological characteristics, ozone reduction is
particularly challenging and will require extensive mitigation measures both inside and
beyond the region to achieve current standards. In addition, the potential for further
tightening of the ozone standards in the future exists. The EPA is expected to finalize the
new ambient ozone standards sometime in March of 2008. Reduction of NOx emissions
is a primary strategy promoted in the region to reduce ozone formation.
1.2 HGB NOx Overview
The Houston SIP is the primary device used to manage air quality in the region. The SIP
includes information regarding sources of NOx emissions, quantifies NOx emissions, and
addresses strategies for mitigating NOx emissions. In the most recent SIP filing, 3 total
regional NOx emissions for 2008 are estimated to be approximately 548 tons per day,
down from 831 tons per day in 2002.
Table 1-1: NOx Emission Inventory, HGB (2008 RFP SIP)
2002 2008 2008
Base Year Uncontrolled
(tons per
Controlled
Source (tons per day) day) (tons per day)
Point 339.48 381.59 174.89
Area 40.15 55.18 55.18
Non-Road 167.74 243.03 146.66
On-Road 283.2 364.83 171.65
Total 830.57 1044.63 548.38
Source: Houston-Galveston Brazoria Eight-Hour Ozone Nonattainment Area Reasonable Further Progress
SIP, TCEQ, (2006-030-SIP-NR), Adopted HGB RFP SIP Revision Narrative, Adopted by Commission
May 23, 2007
As shown in Table 1-1, about 58% of NOx emissions come from mobile sources,
including cars, trucks, locomotives, airplanes, ships, and construction equipment.
Because on and off-road vehicles now generate a majority of the region’s NOx emissions,
state and federal programs are focused primarily on reducing emissions from non-road
equipment and on-road vehicles. State government is pre-empted by federal law from
3
See http://www.tceq.state.tx.us/implementation/air/sip/hgb.html#rfp. This site was last accessed on
February 14, 2008.
2