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57th Meeting of the Joint Advisory Committee for the Improvement of Air Quality in the Ciudad Juárez, Chihuahua / El Paso, Texas / Doña Ana County, New México Air Basin ASARCO Chimney Demolition Dust Monitoring. PRESENTATION BY Texas ASARCO Custodial Trust. May 23, 2013. Discussion Topics.
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57th Meeting of the Joint Advisory Committee for the Improvement of Air Quality in the Ciudad Juárez, Chihuahua / El Paso, Texas / Doña Ana County, New México Air BasinASARCO Chimney Demolition Dust Monitoring PRESENTATION BY Texas ASARCO Custodial Trust May 23, 2013
Discussion Topics • Site Preparation • Pre-Demolition Concrete Sampling • Dust Monitoring Network • Dust Monitoring Results
Dust Suppression Techniques Employed • There were four primary measures employed to minimize dust issues • Chimney preparation (removals of loose materials and interior coatings) • Cushioning layers • Earthen Berms • Water mist dust capture
Chimney Preparation • Vacuum gross dust from the annulus base of the 828’ chimney • Remove insulation material from the interior of the 828’ chimney • Vacuum gross dust from the interior base of the 612’ chimney • Sprayed tactifier on interior of chimneys
Chimney Demolition Fall Zone Preparation • 10-ft berms around fall zones • Geotextile layer over site soils • Imported soil fill over geotextile layer (analyzed before importing) • Soil binder applied over imported soils
Chimney Demolition Mist System • Efficient water delivery system and dust reduction technique • 26 Large mist units on berms around fall zones • 2 Elevated units at the base of fall zones
Chimney Demolition Fly Rock Impact Reduction • Installed large metal containers behind each chimney • Installed covers over the canal near the site • Installed covers over chimney flue openings
Cushioning Layers and Earthen Berms Layout Cushioning Layers Earthen Berms 4/2/13
Chimney Pre-Demolition Sampling & Analysis • Cores from 10-ft, 50-ft and 100-ft above ground surface on each chimney • Crushed and analyzed for: • Metals • Crystalline Silica • SVOC • VOC • Chemical weapons degradation products • Rad • The analyses results indicated that the concrete did not contain constituents of concern in concentrations that would pose a health concern.
Coordination with Local, State and Federal Authorities • The Trust proactively sought the participation of local, state and federal authorities on both sides of the border. • The Trust hosted monthly preparation meetings with both Mexican and United States authorities starting in February, 2013. Weekly meetings were held from the third week of March up to April 12th • The Trust is indebted to all of the agencies that provided support and advice. • The City of Juarez Proteccion Civil and Ecology Departments in particular were very helpful in augmenting the dust monitoring program in Juarez. Just as helpful was the City of El Paso, which allowed the Trust access to their dust monitoring network.
Onsite Air Monitoring Plan Onsite Monitoring: 16 dust monitoring locations (DustTraksTM) 3 chemical sampling locations (BGI Model PQ100) Compare results to: National Ambient Air Quality Standards (NAAQS) PM10, PM2.5 and Lead Texas Commission on Environmental Quality (TCEQ) Effects Screening Levels (ESLs) and Ambient Air Monitoring Comparison Values (AMCVs) Other Metals
Approved Air Monitoring Plan ONSITE MONITORING
Offsite Air Monitoring – Dust Monitoring • Direccion General de Ecologia y Proteccion Civil del Municipio de Juarez (DGEyPC) Wedding and Associates High-Volume PM10 Sampling • TCEQ High-Volume PM10 Sampling
Onsite Air Monitoring Results – PM10/PM2.5 *Analytical Results
Air Monitoring Results – Offsite PM10/PM2.5 • No 24-hour concentrations recorded greater than NAAQS • Elevated offsite concentrations (greater than NAAQS) lasted approximately 1 hour
Offsite Air Monitoring Results – PM10/PM2.5 *Analytical Results
Results • PM10: Concentrations at all locations monitored were below the 24-hour average NAAQS of 150 µg/m3, with the exception of the onsite West location which was 152 µg/m3 • PM2.5: Concentrations at all offsite locations were below the 24-hour average NAAQS of 35 µg/m3. Concentrations at three onsite locations (South West, East, and West) were above NAAQS, but downwind location (South) was below the NAAQS • Metals: 24-hour average concentrations were all below the TCEQ short-term ESLs and AMCVs • Pre- and post-demolition chemical concentrations are similar
Conclusions • Site Engineering Controls worked as intended to minimize dust • Onsite (TCT) and Offsite (DGEyPC & TCEQ) Sampling Locations recorded similar data • Off-site monitoring data is below NAAQS • Concentrations of metals were below TCEQ short-term screening levels • Data analyses indicate no long-term effects from the demolition of the two chimneys