A7+-+NDDEQ+PCM+Clearance+Testing+June24.docx

4201 Normandy Street | Bismarck ND 58503-1324 | Fax 701-328-5200 | deq.nd.gov

Bismarck ND 58501

PHASE CONTRAST MICROSCOPY (PCM) CLEARANCE TESTING (rev. 6/24)

DEFINITIONS

A. ACBM - Asbestos Containing Building Material.

B. ACM- Asbestos Containing Material, shall mean asbestos or any material containing more than one percent asbestos.

C. NDDEQ – North Dakota Department of Environmental Quality.

D. HEPA filter - A high efficiency particulate air filter capable of trapping and retaining 99.97 percent of particles greater than 0.3 micrometers mass median aerodynamic equivalent diameter.

E. HEPA vacuum equipment - A vacuum cleaner which has been designed with a HEPA filter as the last filtration stage, not a vacuum that can be fitted with a HEPA filter in place of the original basic filter. The vacuum cleaner must be designed so that all the air drawn into the machine is expelled through the HEPA filter with none of the air leaking past it. HEPA vacuums must be operated and maintained in accordance with the manufacturer's instructions. Make sure that your HEPA vacuum meets these requirements ask the manufacturer or retailer whether the machine has been tested to ensure that it achieves the high efficiency required of a HEPA filter (capturing 99.97% of 0.3 micron particles).

F. Homogeneous Work Area - Shall mean designated rooms, spaces, or areas of the building or structure where asbestos abatement activities take place. For the purpose of the survey of a building for asbestos, the work area is the premises, or those portions of the premises where the renovation, alteration work or portion of the work area which contains one type of asbestos-containing material and/or where one type of abatement is used.

G. NIOSH - National Institute for Occupational Safety and Health, a U.S. government agency that researches worker safety and health. NIOSH recommends changes in the regulations to OSHA.

H. OSHA – The Occupational Safety and Health Administration, A U.S. government agency that covers worker safety and health on the job.

I. PCM - Shall mean the measurement protocol for the assessment of the fiber content of air. (NIOSH Method 7400) as most recently amended.

J. Volume - is the measurement of space a three-dimensional shape takes up with three dimensions: length, width, and depth.

K. Wet Methods - shall mean the removal of asbestos fibers from building surfaces and objects by using cloths, mops, or other cleaning tools which have been dampened with water.

L. Work Area - shall mean designated rooms, spaces, or areas of the building or structure where asbestos abatement activities take place. For the purpose of the survey of a building for asbestos, the work area is the premises, or those portions of the premises where the renovation, alteration work or portion of the work area which contains one type of asbestos-containing material and/or where one type of abatement is used.

M. Work Site - Premises where asbestos abatement activity is taking place and may be composed of one or more work areas.

CLEARANCE TESTING

A. Overview

To determine if the elevated airborne asbestos structure concentration encountered during abatement operations has been reduced to the specified level, the air monitoring firm will secure samples and analyze them according to the following procedures:

a. Clearance monitoring, including visual inspection and final air testing.

b. Aggressive sampling procedures as described below will be followed.

c. Samples will be collected and analyzed as indicated below.

d. Every clearance sample:

a. Upon meeting the PCM clearance requirements.

b. The level is 0.01 f/cc or lower, based on each result.

c. Minimum of 5 air samples will be collected for analysis and at least one sample per room, whichever is greater shall be collected and analyzed in the work area.

B. Visual Inspection Final air testing work of this section will not begin until the visual inspection described below is complete.

a. The cost of providing visual inspection must be included in the bid response.

b. A visual inspection involves visually examining the asbestos removal area for evidence that the abatement has been successfully completed, including thorough clean-up.

c. Visual inspection shall be performed by a qualified third party contractor that is independent of the abatement contractor and licensed by the NDDEQ’s Asbestos Control Program. Any individuals performing visual inspections for the third party contractor must be certified by the NDDEQ’s Asbestos Control Program.

d. Confirm that all containerized waste has been removed from work and holding areas and there is no visible ACM debris or residue on or about all abated surfaces.

e. The inspection should be conducted as rigorously as possible, with all spaces and surfaces where the abatement was conducted being extensively examined for residual ACBM debris. The inspection may involve:

· Scrutinizing every corner and crevice of the area within the containment barriers used to isolate the functional space for the response action.

· Using a ladder to inspect hard-to-physically-reach areas.

· Brushing or wiping surfaces to detect dust.

· Using a flashlight beam to detect loose debris or airborne residue.

· Using a damp cloth to detect dust.

· Inspecting permanent fixtures in the area, such as ceiling tile grid bars, pipes, ducts, etc.

· Inspecting for asbestos-laden water, which may have leaked from the enclosure onto floor surfaces beneath the abatement area.

· Examining surfaces for water and/or debris markings.

· Checking crawl spaces on hands and knees; dirt floors may contain pulverized or impacted asbestos debris.

f. The goal of the visual inspection is to ensure that:

· Seals on windows, doors, and vents remain in place during final air monitoring.

· Isolation barriers separating the abatement area from non-abatement areas are in place.

· No evidence of residue, debris, or dust is present in the abatement area.

g. The presence of any visible residue on surfaces within the abatement area indicates a need for additional cleaning of the surfaces. If an area passes visual inspection but then fails to meet air sampling and analysis requirements after that inspection, the site must be recleaned and an additional visual inspection be conducted to detect any material that may have been uncovered or released during recleaning.

h. Only after visual inspection clearance has been completed may final air sampling be done.

i. The results of the visual inspection always need to be documented and signed by the person conducting the visual inspection.

C. Aggressive Sampling

All air samples will be taken using aggressive sampling techniques as follows:

a. Before sampling pumps are started, the exhaust from forced-air equipment (i.e., leaf blower with approximately 1 horsepower electric motor) will be swept against all walls, ceilings, floors, ledges and other surfaces in the room. This procedure will be continued for 5 minutes per 10,000 feet of room volume.

b. One 20-inch-diameter fan per 10,000 cubic feet of room volume will be mounted in a central location at approximately 2 meters above the floor, directed towards the ceiling and operated at low speed for the entire period of sample collection.

c. Air samples will be collected in areas subject to normal air circulation away from HEPA units, room corners, obstructed locations, and sites near windows, doors or vents.

d. After air sampling pumps have been shut off, fans can be removed from the area.

D. Sample Quantities/Analysis (PCM)

a. In each homogeneous work area after completion of all cleaning work, a minimum of 5 air samples will be collected for analysis and at least one sample per room in the work area.

b. Sample quantities are based on work area volume of less than 25,000 square feet. For work areas larger in size, one additional sample should be collected for every 5,000 square feet over 25,000 square feet.

c. Samples will be collected on 25mm cassettes with extension cowl and 0.8 micron mixed cellulose ester filter media.

d. Analysis: Fibers on each filter will be measured according to the NIOSH 7400 Method, must be followed for the collection and analysis of clearance air monitoring samples.

e. The chain of custody will document the flow rate, sampling start and stop times, the specific location of each sample, a unique ID number for each sample, the date of sample collection, the date of sample analysis, documentation of a reference slide, the name and license number of the person collecting samples, and the name and address of the facility.

f. Release criteria: Decontamination of the work site is complete when every clearance sample collected is at or below 0.01 fibers per cubic centimeter. If any sample is above this level, the decontamination process is incomplete and these areas need to be recleaned and retested.

g. Each homogeneous work area which does not meet the clearance criteria shall be thoroughly recleaned using wet methods, with the negative pressure ventilation system in operation. After allowing sufficient time for drying of the work area, HEPA vacuums shall be used to thoroughly clean all surfaces after gross clean-up. New samples shall be collected in the work area as described above. The process shall be repeated until the work site passes the test.

h. The asbestos project may not be cleared until after the final visual inspection and after the results of all required air clearance samples demonstrate that asbestos concentrations do not exceed 0.01 f/cc or lower, based on each result.

Clearance air monitoring results shall be submitted directly to the NDDEQ within 48 hours of testing.

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