Monitoring & Oversight Activities Conducted During Lead Remediation of Elevator Structure Located at Carlsbad Caverns National Park

Transcription

1 Monitoring & Oversight Activities Conducted During Lead Remediation of Elevator Structure Located at Carlsbad Caverns National Park James Lieberman, CIH Environmental Information Services

2 Section 1.0: Introduction

3 Scope of Project EIS contracted to conducted IH services during the period of April 11-14, 2016 at Carlsbad Caverns, NM during operations to remove lead paint & scale from structural steel within elevator shafts 1 & 2. Verify the collection and analysis of personnel exposure air samples for lead by the Contractor in accordance with (OSHA) requirements Conducted third party environmental monitoring and QA inspections Ensured that contractor s activities did not adversely affect the visitor center, NPS personnel or cave.

4 Background of Elevator Shafts JVA Consulting Engineers performed an initial structural assessment of steel beams within the western elevator shaft housing Elevators #1 and #2 in March & April The goal of their task order was to provide repair recommendations for a short term and immediate 3 to 6 year to repair corroding steel support beams These repairs are intended to extend the service life of the corroding beams until funding for more comprehensive, long-term repairs can commence The Carlsbad Cavern Elevators #1 and #2 were the original elevators for visitor access from the upper level visitor's center to the cave floor approximately 750 feet below. These elevators were installed in 1932 with the adjacent new passenger Elevators #3 and #4 installed in 1954

5 Arrangement of Elevators in Lobby

6 Elevator Shafts 1-4

7 Background of Elevator Shafts Two elevators are located within the approximately 14' -8" foot by 8-6" rectangular shaft cut into the surrounding limestone. The interior faces of a majority of the shaft are lined with a thin layer of shotcrete. Each elevator has four guide rails. The 15 lb. guide rails align the cable-supported elevators during normal operations. During emergency braking, the vertical guide rails also act as columns, taking cab gravity loads to the limestone floor at the base of the shaft. There are sets of three horizontal support beams at approximately 10 foot vertical spacing that brace the vertical guide rails. The beam ends are embedded in grout pockets in the limestone shaft walls.

8 Inside the Elevator Shafts

9 Background of Elevator Shafts At many locations we noted a layer of bright orange paint below the grey top coating of paint. It is very possible that this orange paint is the same "universal orange" paint that was found to contain lead in the Elevator 3 & 4 repair project.

10 Specific Logistics The anticipated work areas are on the top of the elevator cabs. There is room for 2 people on the top of each cab. There are numerous elevator mechanical/electrical systems located at the top of the cab that must be protected during the work. There is no adequate available electrical power source for power tools at the top of the cabs. The contractor will need to lower an extension cord to the work location. There are numerous cables and conduits that run vertically in the shaft that will hinder contractor access to execute the repairs. There may be lead paint present in the existing coatings.

11 Top of the Elevator Cab

12 Section 2.0: Activities Conducted

13 Initial Activities Conducted on Site Met with Park Service Representatives to review project Met with the Contractor s safety and industrial hygiene representative to review the safety & IH protocols for the project Before on-site work began, conducted an IH review of contractor s Environmental Control Plan, Health and Safety Plan including a Respiratory Protection Program, Medical Surveillance Program and Accident Prevention Program Ensured that contractor s representative conducted OSHA required worker air monitoring according to appropriate standards

14 Meeting with Contractor Safety Rep Met with the contractor s onsite safety representative to further discuss the ventilation plan for the elevator shafts. It was decided to place two 6,700 cfm fans in the opening of elevator #4 to blow air down the shaft and have it rise and exhaust out of elevator shafts 1 & 2 to provide ventilation for workers and operation within the shafts.

15 Fans in Elevator Shaft #4

16 Lower Elevator Atrium Before Work

17 Meeting with Contractor Safety Rep Reviewed the safety protocols for the project The contractor s Environmental Control Plan, Health and Safety Plan including a Respiratory Protection Program, Medical Surveillance Program and Accident Prevention Program. These were summarized in the Activity Hazard Analysis Dated March 2016.

18 Meeting with Contractor Safety Rep EIS reviewed of the contractor s activity hazard analysis and EH&S programs found that they were sufficient for the contracted tasks. Employees were supplied with appropriate personal protective equipment, 4-gas monitor, waste containers and other equipment necessary to safely conduct the work. Contractor s employees wore fall protection harnesses and lanyards during the work. Fall protective barriers were constructed and placed in front of elevator shaft openings.

19 Fall Protective Barriers

20 Meeting with Contractor s IH Technician Met with Mr. Greg Estes, IH with Landmark Environmental, to review the media, methods and anticipated plan for worker air monitoring for lead to be conducted once de-scaling operation were to begin. The anticipated sampling plan and methods were in conformance with generally accepted IH standards for employee exposure monitoring.

21 Activities on Monday April 11 At approximately 3:25 PM, two air-blowing fans were installed in elevator shaft #4 at the lobby level to blow air into the lower elevator atrium 750 ft below and then be exhausted up elevator shafts 1 and 2. The doors in the lower elevator atrium area were covered with plastic. Plastic was also placed over the entry door to the lobby level atrium area and all ventilation ducts were masked off with plastic to preclude contaminants to be introduced into the HVAC system. At about 3:30 the relative humidity outside was about 28% and the weather was clear and sunny. The outside temperature was 69 F. It was hoped that blowing low relative humidity warm air down the elevator shaft would help to dry out the elevator shafts.

22 Initial Measurements for Ventilation At 4:08 PM, Mr. Lieberman checked the airflow from the elevator atrium room to the hallway in the visitor s center with the door closed and the reading was less than 20 ft/min at the doorway.

23 Lobby Level Elevator Atrium

24 Revolving Doors on the Cavern Side

25 Activities on Tuesday April 12 Set up IAQ and particulate monitoring and took readings at elevator shafts 1 and 2. On Monday, only one elevator shaft was open but on Tuesday both elevator doors were open. When will contracted job responsibilities will be completed? Necessary tasks could not be completed until after conducting wipe samples from the elevator atrium areas. Mr. Lieberman walked down to the cavern to conduct air-monitoring; He arrived at the base of the elevator shafts in the caverns at approx. 2:45 pm and conducted measurements for temperature, relative humidity, and particulate in and around the elevator landing area.

26 Personnel Air Monitoring Sampling The LM technician assigned to the project collected air monitoring samples for two employees conduction lead paint & scale removal for three days. The required (OSHA) Permissible Exposure Limit (PEL) for lead is no greater than 50 µg/m 3 averaged over an 8-hour period. The American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value time weighted (TLV-TWA) average is 50 µg/m 3. The air monitoring sample analysis results for the employee s exposure were below OSHA s Permissible exposure limits. EIS provided oversight for the sample collection

27 Personnel Air Monitoring Sampling: Summary of Selection Findings The results of the remediation workers breathing space air monitoring samples showed a maximum of 17.1 µg/m 3 and average levels of lead (11.2 µg/m 3 ). Average values were 22.4 percent of OSHA PEL. Workers wore half faced air purifying respirators with a protective factor of at least 10. Therefore, the average airborne concentration of lead was 2.24 % of the maximum that the personal using respiratory protective equipment could be exposed to. In summary, the remediation workers were not exposed to airborne levels of lead that were of concern.

28 Environmental Monitoring: Sufficient Ventilation We ensured that sufficient ventilation (air flow) was provided for employees working within the elevator shaft. Inspected the temporary isolation barriers (plastic sheeting) erected in the lower & upper elevator atrium areas to ensure that dust generated by operations would not migrate outside of the containment. Measurements were conducted at the top and bottom of the elevator shafts and in the adjacent areas during the week.

29 Environmental Monitoring: Process of Ensuring Sufficient Ventilation was Provided In order to verify that operations were not adversely impacted the environment we collected particulate, temperature and relative humidity readings within the cavern, at areas adjacent to the elevator shafts and openings, while lead paint removal and scale operations were being conducted. These real-time measurements were taken to ensure that no significant amounts of contaminants were being released into the environment of the cave or other occupied area and that the caverns temperature and RH were not adversely impacted.

30 Environmental Monitoring: Process of Testing Temperature, Relative Humidity and Particulate Matter The following instruments were used: A calibrated TSI Inc. Q-Trak QK013 Indoor air quality monitor A calibrated TSI AM510 particulate air monitor

31 Monitoring Equipment in Lobby Level at Elevator Openings 1 & 2

32 Particulate Air Monitor in Use

33 Environmental Monitoring: Summary of Differences in Airborne Particulate, Relative Humidity and Temperature Baseline: Measurements collected the previous day on April 11 th, ranged from a temperature of 56.5 to 57.9 and a relative humidity of 85 to Baseline conducted on April 11 th between 11:00 and 11:26 AM that showed a value of mg/m 3 to mg/m 3 During Operations: On April 12 th the temperature in the cave measured between 56.9 to 57.5 F Relative humidity measured The particulate reading in the cave measured mg/m 3, measurements of particulates made in the air lock mg/m 3. Adjacent to the elevator doors were between to mg/m 3.

34 Environmental Monitoring: Summary of Differences in Airborne Particulate, Relative Humidity and Temperature There was no significant difference in the airborne particulate in and around the elevator shaft openings in the cavern based on the real time measurements at the bottom of the cave conducted before operations began and during operations, nor were there any significant difference in the temperature and relative humidity readings. Airborne concentrations of lead at the opening of elevators 1 & 2 at the lobby level did not show detectable levels of lead.

35 Environmental Monitoring: Table Summary Day 1: 4/ In lower level elevator atrium at bottom of cave Day Temperature: Fahrenheit Relative Humidity: Percentage Particulate Mg/m3 Location 4/ Elevator Atrium ground/lobby level 4/ Elevator Atrium ground/ lobby level 4/ Elevator Atrium ground/lobby level 4/ Elevator Atrium ground/lobby level

36 Activities on Wednesday April 13 Continued to monitor for relative humidity, temperature and air flow at intervals of between every half hour to hour; created a sampling plan to conduct wipe sample operations Reviewed waste samples collection with IH, made sure that representative samples were taken for TCLP Hazardous waste analysis determination

37 Waste Stream Sampling: Process of Sample Collection EIS supervised the collection of two waste stream samples Paint chips & rust scale Used PPE. Samples were submitted to Reservoirs Laboratory under chain of custody by contactor s IH technician. The paint chip waste stream was determined to be characteristically hazardous for lead, PPE waste steam was determined not to be hazardous. Analysis of the paint chip and metal debris TCLP sample resulted in a concentration of 162 milligrams per liter (mg/l) leachable lead and the PPE waste stream sample resulted in a concentration of 0.27 mg/l lead. The EPA limit is 5.0 mg/l lead for hazardous waste

38 Paint Chip Waste

39 Waste Stream Sampling: Observations and Sampling Results (Landmark s Observations) There are two occupational limits for lead: Action Level (AL) of 30 micrograms per cubic meter (μg/m3) The permissible exposure limit (PEL) of 50 μg/m3 All worker exposure assessment air samples resulted in concentrations below the AL. All ambient air samples collected from the lobby results in concentrations below the reporting limit (BRL) for the laboratory.

40 Waste Sample Collection

41 Activities on Thursday April 14 7:50 AM set up the IAQ and particulate monitor. By 9:00 am workers had completed de-scaling operations and were in the process of cleaning the lower and upper atrium areas prior to wipe sampling. At approximately 10:00 am started to sample the lower atrium and at approximately 10:30 the upper atrium areas. Refer to sketch of the upper elevator atrium that shows approximate sample locations.

42 Sample Locations in Upper Atrium

43 Wipe Sampling: Health-Based Limits The wipe sampling results were reported in units of cm μg/100 sq. cm representing the mass of the analyte collected per 100 square centimeters of area sampled; although an area of 1 square foot was actually sampled. The screening levels were adapted from those published by the Contaminants of Potential Concern (COPC) Committee of the World Trade Center Indoor Air Task Force Working Group2. The risk established for these screening levels was set by the COPC Committee Working Group at 1 x 10-4 (a 1 in ten thousand risk).

44 Wipe Sampling Cavern Level

45 Wipe Sampling Ground Level

46 Wipe Sampling: Health-Based Landmarks This risk level represents a reasonable compromise in sample collection and analysis for a screening program. Analytical interferences would also be substantially increased. Adopting these health-based benchmarks is also advantageous because they have been peerreviewed and accepted. Note: 2.70ug/100cm 2 is equal to 25 ug/ft 2. Analyte Screening Level (ug/100 sq. cm) Lead 2.70

47 Wipe Sampling: Upper Elevator Atrium Area Locations and Results On the morning of April 14, 2014, Three samples were taken from the floor and one from the wall of the lower and upper elevator atriums after paint chip and de-scaling work had ceased and the SIS crew had conducted an initial cleaning of the area. Samples were taken from areas in front of the elevators, the center of the room and on the wall between the elevators. Lower -The highest concentration was 0.77 ug/100 cm 2 Upper- The highest concentration was 2.40 ug/100 cm 2.

48 Section 3.0: Conclusions and Recommendations

49 Conclusion The results of the monitoring and sampling efforts were presented with relevant comparison concentration guidelines. Without exception the results show that neither workers nor the environment were adversely affected by activities. Samples did not display lead concentrations above the OSHA, ACGIH or Contaminants of Potential Concern (COPC) maximum concentration limits. Note: Samples were not taken in some areas expected to be occupied in the future, nor were sufficient samples taken to statistically prove the null theory. The elevator cars were not sampled. Therefore we recommend further sampling.

50 Recommendations After all operations that may disturb lead paint and site cleaning has been completed, we recommend that wipe samples be taken from areas that will be occupied by NPS personnel and visitors that may have been impacted by construction activities to insure that lead levels are below levels of concern. Such areas would include; the upper and lower elevator loading areas (elevator atriums) and the elevator cars. We would suggest taking wipe samples from walls and floors of these areas.

51 James Lieberman Environmental Information Services, Inc.

52 References Sax s Dangerous Properties of Industrial Materials, Ninth Edition, Prichard J. Lewis, Van Norstrand Reinhold, OSHA - Occupational Safety and Health Standards Z Toxic and Hazardous Substances ACGIH - The Threshold Limit Values (TLVs ) and Biological Exposure Indices (BEIs ) Surface Wipe Sampling Procedure IH World Trade Center Indoor Environment Assessment: Selecting Contaminants of Potential Concern and Setting Health-Based Benchmark