Study Participants and Reviewers

Transcription

1 Second Avenue Subway (SAS) Construction Phase Air Monitoring Study Presentation at Community Board 8 SAS Task Force January 26, 2012 by Guido Schattanek, QEP Principal Professional Associate Senior Environmental Engineer GREEN Group PB New York Study Participants and Reviewers Parsons Brinckerhoff Green Group/TRC conducted study ENVIRON peer review EPA Region II consultation NYSDEC Review

2 Presentation Agenda Study objectives Air pollutants monitored Monitoring locations Air quality benchmarking Summary of findings Study Objectives Assess the effects of construction activities and underground blasting on air quality Assess the odor effects of construction activities Contractor s air monitoring program assessment

3 Monitored Air Pollutants PM 10 (coarse particles - less than 10 microns) PM 2.5 (fine particles - less than 2.5 microns) Silica Carbon monoxide (CO) Sulfur dioxide (SO 2 ) Ammonia (NH 3 ) Hydrogen sulfide (H 2 S) Nitrogen oxides (NO & NO 2 ) Total volatile organic compounds (VOC) Visible Dust Blasting, excavation Demolition Road dust PM 10 Same as above PM 2.5 Regional pollution Fuel combustion Diesel exhaust Particulate Matter

4 Silica Silica is one of the most common elements on earth (soil, sand, glass, rocks, etc) Present in Manhattan rock as: quartz, cristobalite and tridymite Air Quality Gases Carbon monoxide (CO), Sulfur dioxide (SO 2 ), Ammonia (NH 3 ), and Hydrogen sulfide (H 2 S) Present in an urban environment Potential sources Motor-vehicles emissions Residential/commercial fuel combustion Possible byproduct from blasting and construction operations

5 Odor Producing Gases Ammonia (NH 3 ) Hydrogen sulfide (H 2 S) Sulfur dioxide (SO 2 ) Nitrogen oxides (NO & NO 2 ) Air Monitoring Locations 10 locations selected in consultation with EPA to: Capture the effects of construction activities Represent worst case public exposure Provide sufficient coverage to capture multiple wind directions

6 Locations of Monitoring Sites Site Number and Contract Location 1 (C4B) 69 th St. NE corner 2 (C4B) 69 th St NW corner (3 rd floor) 3 (C4B) 70 th St NE corner (Hog house) 4 (C4B) 72 nd St. SE corner 5 (C4B) 72 nd St SE corner (3 rd floor) 6 (C4B) 73 rd St NE corner 7 (C5A) 83 rd St SE corner 8 (C5A) 83 rd St NW corner (3 rd floor) 9 (C5A) 86 th St NE corner 10 (C5A) 87 th St SE corner Monitoring Equipment Sites 4 & 5 72 nd Street

7 Air Quality Benchmarking Identified values intended to protect public health Selected the most conservative values Done in consultation with EPA Air Quality Benchmarks National Ambient Air Quality Standards (NAAQS) adopted by NYSDEC NYSDEC Short and Long Term Guideline Concentrations One hour Acute Exposure Guideline Level-1 (AEGL-1) National Advisory Committee WTC Indoor Air Task Force Guidelines

8 National Ambient Air Quality Standards (NAAQS) Health based, conservatively set to protect sensitive populations Reevaluated every 5 years by EPA/Clean Air Scientific Advisory Committee (CASAC) Pollutants in this study Particulate Matter (PM 10 and PM 2.5 ) Carbon monoxide (CO) Sulfur dioxide (SO 2 ) Air Quality Guidelines NYSDEC Short and Long Term Guidelines NH 3 National Advisory Committee (AEGL-1) H 2 S WTC Indoor Air Task Force Working Group Respirable Silica

9 Selected Benchmarks Pollutant Time Period Exposure Benchmark Level Source PM 10 Daily 150 ug/m 3 NAAQS PM 2.5 Daily 35 ug/m 3 NAAQS CO 1 Hour 35 PPM NAAQS SO 2 1 Hour PPM NAAQS NH 3 1 Hour 3.4 PPM NYSDEC H 2 S 1 Hour 0.51 PPM AEGL-1 Silica 24 hours 10 ug/m 3 WTC-IATF Odor Investigation NH 3, H 2 S, SO 2, NO and NO 2 data was analyzed to determine odor detection Interviews with a sample of concerned residents Odor description by observers was defined as fireworks, acrid, sulfury, gunpowder and smoky

10 Odor Thresholds and Description Compound Odor Threshold (PPM) Irritation Threshold (PPM) Odor Description Ammonia (NH 3 ) Sharp pungent Hydrogen Sulfide Rotten eggs (H 2 S) Nitric Oxide (NO) NA Sharp sweet Nitrogen dioxide (NO 2 ) Acrid bleach-sharp biting Sulfur dioxide (SO 2 ) Burn matches, metallic taste, sharp pungent Contractor s Air Monitoring Program Evaluation Contractor s air program measures PM 10 and VOC Monitors were co-located with contractor monitors Data collected from both monitors were compared for consistency

11 Study Findings Air Quality Conclusion Data* shows that Second Avenue Subway construction does not present an immediate or long term threat to public health * Based on 3.3 million data points collected between September 12 th and October 8 th, 2011

12 PM 10 Findings PM 10 Daily (24 hour) levels: 5 to 60 ug/m 3 All levels below the benchmark of 150 ug/m 3

13 PM 10 Daily Levels at all Seven Sites

14 PM 2.5 Findings Benchmark is 35 ug/m 3 PM 2.5 Daily (24-hour) levels: 2.5 to 39.8 ug/m 3 A single exceedance of the benchmark occurred at each of three monitors: 69 th street site on 9/14 (36.3 ug/m 3 ) 72 nd and 83 rd street sites on 9/27 (39.8 and 35.2 ug/m 3 ) Analysis of the hourly data on those days indicated no effect from blasting

15 PM 2.5 Daily Levels at all Three Sites

16 PM 2.5 Hourly Distribution on Days above Benchmarks

17 Respirable Silica Findings All daily levels below Benchmark of 10 (ug/m 3 )

18 Air Quality Gases Findings CO all data below the benchmark NH 3 levels below the benchmark for 99% of the time Readings slightly exceeded the benchmark at 69 th and 86 th streets at six events None of them coincided with blasting times H 2 S all data below the benchmark Gases Findings SO 2 levels not detected or below benchmark 99% of the time. Benchmarks exceeded during six days for 13 hours total at three monitoring sites These isolated events triggered an investigation on the possible causes of SO 2

19 SO 2 Investigation Effort included Analysis of the chemical make up of construction materials no source of SO 2 detected SO 2 monitoring using handheld monitors at different construction activities - SO 2 not detected Several lab analysis of blasting emissions (NIOSH 6004 test) - SO 2 was not detected Rock core samples analysis for sulfur - very low, less than 0.75 percent SO 2 concentrations could not be traced to blasting operations or other construction activities Odor Evaluation Findings All data was below the irritation threshold All five compounds were periodically detected above the odor detection threshold Odor intensity during blasting events was rated moderate (5 on a scale of 1 to 8) by odor specialist

20 Data Findings Contractor s Air Monitoring Program Contractor PM 10 levels below benchmark Contractor VOC levels overstated Lack of regular instrument calibration and maintenance produced inconsistent data Recommend daily calibration and proper maintenance Conclusions Data shows that Second Avenue Subway construction does not present an immediate or long term threat to public health Data shows occasional presence of odors of moderate intensity that are below irritation thresholds

21 Recommendations Continue improved smoke and dust control for the 72 nd Street Station contract area Monitor PM10 and PM2.5 for the 86 th Street Station contract Baseline prior to blasting period During initial period of blasting operations