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

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) 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

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 day). We generally use 24 hr samples collected every 6 th 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