air toxics monitoring in the houston- galveston area david brymer, texas commission on environmental...
TRANSCRIPT
Air Toxics Monitoring in the Houston-Galveston Area
David Brymer, Texas Commission on Environmental Quality
General Monitoring Information
• >140 monitors (not including weather) at >45 fixed air monitoring sites in the Houston-Galveston area
• >25,000,000 air quality measurements
This represents almost a third of the fixed site air monitoring done in the State of Texas
Continuous Monitoring Sites
www.tceq.state.tx.us/subject/subject_air.html
Topics of Discussion
• Who is doing this monitoring?• Where are we monitoring Air Toxics?
– Network Design (why are we monitoring where we are?)
• What compounds are we monitoring?• How are we monitoring Air Toxics?
– Types of monitoring– Technology used/ Sampling frequency
Who Does this Monitoring?• Governmental Agencies
– EPA
– TCEQ
– Local Governments (HCPC, GCHD, etc..)
• Citizen Groups • Industry
– Consortiums (HRM)
– Individual facility fenceline and/or on-site monitoring
Network Design
• Fixed sites – Sited to address a specific monitoring objective
• Mobile sites – Screening or addressing a specific concern/
incident– Upwind/downwind
Fixed Air Toxics Monitoring Sites in the Greater Houston-Galveston Area
EISM Sites
HRM Sites
TCEQ Sites
Other
Air Toxics Related Projects with Fixed Sites
• National Air Toxics Trends Sites (NATTS) – EPA• Photochemical Assessment Monitoring Stations
(PAMS) – EPA• Community Air Toxics Monitoring Network
(CATMN) – State• Houston Regional Monitoring Network – Industry• Supplemental Environmental Projects/Agreed
Order Monitoring – Gov’t/Industry
CATMN
• Legislative directive in 1992
• Assess community exposure to VOC concentrations
• Determine potential long-term health effects
• Data used to assess temporal/spatial variability
CATMN Site Considerations
• Magnitude of pollution emissions within 10 km radius
• Predominant wind direction/wind rose• Population density• Traffic patterns• Degree of public concern• Logistical considerations
– 40 CFR Part 58, App. D & E– Access to the site
• Available data – mobile monitoring
Toxics Monitoring Sites
Air Toxics Monitoring Sites
Houston/Beaumont CATMN
PAMS Monitoring
– Monitoring required in non-attainment areas (1990 CAA Section 182[c][1])
– Enhanced monitoring of ozone, its precursors (VOCs which include some air toxics & NOx) and influencing factors (meteorology and solar radiation)
– In the Houston area this requirement includes upwind (Galveston), area of anticipated max VOC emissions (Clinton Dr), and downwind (Aldine)
National Air Toxics Monitoring Strategy
• Urban Air Toxics Strategy (UATS) -1999• Attain substantial reduction of Non-cancer HAPs• Attain 75% reduction of cancer drivers from 1993
levels
• Monitoring Goals– Trends– Exposure Assessments (ambient measurements as a
surrogate for actual human exposure)– Air Quality Model Evaluation
22 NATTS sites– 15 urban (1 in Tx – Deer Park)– 7 rural (1 in Tx – Karnac)
What Compounds are Being Monitored?
• Criteria Pollutants (ozone, particulate, CO, SO2, NO2, and lead)
• Volatile Organic Compounds – 1 to over 150 compounds at a given site– Includes HRVOCs and air toxics at most sites– Dependent upon monitoring method and
project/site objectives
What are Hazardous Air Pollutants (HAPs)?
• Hazardous air pollutants are those pollutants that are known or suspected to cause cancer or other serious health effects or adverse environmental effects, Source: EPA.
• EPA classified 188 compounds as HAPs in the 1990 Clean Air Act Amendments
• The National Air Toxics Assessment (NATA) study done by EPA in 1990 identified 6 risk drivers of particular interest nationwide.– VOCs – benzene, 1,3-butadiene, acrolein,
formaldehyde– Metals – chromium* and arsenic
• The 1999 NATA study using 1996 data did not identify 1,3-butadiene and arsenic as national risk drivers
Sources of Air Toxics
• Mobile sources • Stationary point sources• Indoor sources • Area sources such as lawn mowing,
heavy machinery, dry cleaners, and printing operations
• Atmospheric reaction products
Where are HAPs Monitored in Houston?
There are 32 TCEQ or industry-funded ambient air toxics monitors in the HGB area (not including SEP & Agreed Order monitoring)
Source: TCEQ
County City, Site
Hourly AutoGC VOCs
24-hour Canister VOCs
1-hour Canister VOCs
24-hour Carbonyls
1-hour Carbonyls
24-hour Metals
Clute, Cobb Field XDanciger, EISM XLake Jackson, EISM XLiverpool, Mustang Bayou, EISM X
Mont Belvieu, HRM XBaytown East, HRM X
Galveston, Airport X X XTexas City, Ball Park XTexas City, Nessler Pool X XTexas City, EISM X
Aldine X XBaytown XBaytown West, HRM XBaytown, Lynchburg Ferry XBaytown, Lynchburg Ferry, HRM XBaytown, Wallisville Rd., HRM XChannelview X X X X XGalena Park XHouston East XHouston, Central Street, HRM XHouston, Clinton Dr. X X X X XHouston, Deer Park #2 X X X X XHouston, Galleria X XHouston, Haden Rd. XHouston, Haden Rd., HRM X XHouston, Milby Park X XHouston, NW Harris County X XHouston, Sheldon Rd., HRM XLa Porte, HRM XLa Porte, San Jacinto Monument XLa Porte, Shore Acres X
Montgomery Conroe, re-located X
Harris
Brazoria
Galveston
Chambers
Houston-Galveston Area HAP Monitors
Legend
TCEQ & EISM sites
HRM sites
How are We Doing Fixed Site Monitoring?
• VOCs (including benzene, 1,3-butadiene)– Automated Gas Chromatographs (11sites) – Passivated Canisters (24 sites)
How are we Doing Fixed Site Monitoring?
• Carbonyls ( including formaldehyde, acrolein)– DNPH cartridge collection and HPLC analysis
– 3 sites
• Metals– Filter collection
and ICP analysis
– 8 sites
VOC Monitoring Approaches
• AutoGC’s– Provide hourly measurements – Provide sub ppbV detection limits– Preliminary data available within 2 hrs – Provides data on HRVOCs and air toxics– Limited target list (non-polar compounds)– Only 1 shot at the analysis– Large capital investment– Generates approx. 500,000 data points/yr
VOC Monitoring Approaches
• Canisters– Can be configured for a wide variety of sample
collection times (<1 min to > 1 day). We generally use 24 hr samples collected every 6th day.
– Can be analyzed for a wide variety of compounds (>100 target compounds).
– Lower initial and on-going costs.– Provide sub ppbV level detection limits with the
ability to reanalyze or dilute a sample – Samples sent back to a lab for analysis. Results are
not available in real-time or near real-time.
VOC Monitoring with Canisters
Event Triggered Can Sampler
Mobile Site Monitoring
• Mobile Laboratory Monitoring (In Field)– TCEQ
• Screening/Incident Monitoring– EPA – TCEQ
• HCPC
• GCPC
• Citizen groups
Mobile Laboratory Capabilities
• Volatile Organics– Screening with portable
GC/MS and other handheld instrumentation (soon to include IR camera)
– In field analysis using GC/PID/FID
– Confirmational sampling via canisters and GC/MS analysis
What is TCEQs Mobile Laboratories Role?
• Find contributors to elevated ambient concentrations measured at fixed sites
• Determine compliance with H2S/SO2/particulate Regulations
• Respond to ongoing complaints that appear to match monitoring capabilities
• Collect enforcement quality data• Identify/quantify air toxics in specific areas
When Roles Do TCEQs Mobile Laboratories not Fill?
• Emergency response (timing, safety, response time)
• General odor complaints (don’t do nuisance odor investigations - can analyze for H2S/SO and organics)
• Source sampling (in most cases)• Not great at monitoring intermittent or
batch operations
Screening/Incident Investigation
• Agency investigators can use screening tools (IR cameras, TVA, OVA,etc) or collect samples (e.g. canisters) that can be sent to lab for analysis
• Citizen group screening