Asbestos Abatement Standard Procedures Indoor Environment Group, Inc.

Transcription

1 The following work procedures are specified on all full containment asbestos abatement projects that we design. A. Preliminary Air Sampling: Many buildings contain background fiber levels prior to, or as a result of construction or renovation work within a building. To determine if such a situation exists, we collect preliminary air samples in each projected work area to establish an alternative indoor air standard before the abatement project begins PCM air samples are collected within 10 feet of where the containment will be constructed. Photo to right - high volume air pump used to collect ambient and clearance air samples B. Posting the Work Site: The licensed asbestos contractor performing the abatement will post in a conspicuous place outside of the abatement area: 1. A copy of the project permit, where required. 2. A copy of the project notice and all written amendments to the project. Photo to right - required postings. C. Lockout-Tagout Procedures: all electrical power and HVAC units serving the work area is shut off and locked out prior to starting abatement procedures. 1. Contractors are required to provide temporary power to the work area and ensure that all extension cords are connected to ground fault interrupters. D. On-site Records: the contractor performing abatement must ensure that the following records are at the work site for the duration of the project: 1. A daily sign-in and sign-out log for individuals entering the containment. 2. A copy of the asbestos project plan. 3. All on-site air monitoring results, including written explanations for high fiber counts. Page 1 of 6

2 4. The negative air pressure measurements, including written explanations for deviations from the minimum requirement. E. Personal Protective Equipment: all project personnel are required to meet minimum personal protective equipment (PPE) requirements which include full body protective suits, respirators, gloves, hard hats and boots. 1. Minimum respiratory protection requirements include ½ face negative pressure HEPA/P100 respirators. 2. Minumum respiratory protection requirements during removal of friable surfacing or TSI is a full face powered air purifying respirator (PAPR). 3. The Occupational Safety and Health Administration (OSHA) requires personal sampling. If air sampling results are high, a different type of respirator may be required. Photo to right - asbestos worker wearing a 1/2 face respirator and personal air pump F. Cleaning the Containment Area Prior to Abatement: All surfaces in the containment area are cleaned before abatement. The following actions must be taken before abatement begins. 1. Uncontaminated moveable objects must be removed from the containment area. 2. Contaminated objects or objects suspected of being contaminated must be HEPA vacuumed, wet wiped or disposed of as asbestos waste. 3. Decontaminated movable objects must be removed from the containment area. 4. Objects and surfaces that will remain in the containment must be cleaned. G. Installation of Critical Barriers: all openings between the containment area and uncontaminated areas are sealed with at least one layer of six-mil polyethylene plastic (poly) to create an airtight barrier. Page 2 of 6

3 1. All objects or structures remaining in the containment must be covered with at least one layer of six-mil poly. 2. All HVAC units servicing the work area must be shut off and locked out. The intake and exhaust openings and seams must be sealed with at least two layers of six-mil poly. 3. All penetrations must be sealed with at least one layer of six-mil poly. 4. All porous surfaces except ceilings must be sealed with at least one layer of six-mil poly. Poly and Duct Tape 5. Any free standing containment wall used, the porous outside of the wall frame must be covered with at least one layer of six-mil poly. H. Containment Construction: All work areas must be enclosed within an airtight containment and must be constructed to isolate the work area from the rest of the building and the outdoors. 1. Floor Sheeting - 2 layers of six-mil poly, covering the entire floor, seams minimized, no seams at wall or floor joints. The first layer must overlap the wall sheeting and the second layer must extend 12 inches beyond the wall or floor joints. 2. Wall Sheeting at least 1 layer of four-mil poly, covering the entire wall, with seams minimized, no seams at wall or floor joints, extend to the deck area and must have a 12 inch by 12 inch clear viewing window, where feasible. I. Posting the Asbestos Work Area: warning signs are displayed at all approaches to the asbestos work area and read as follows: J. Decontamination Units: all persons are required to use a decontamination unit when entering and exiting the containment and it must meet the following conditions: Page 3 of 6

4 1. Be contiguous with the containment area and consist of a clean room, an air lock chamber, a shower, an air lock chamber, and a dirty room. 2. The doorways between the rooms and entrances to the unit protected with two overlapping sheets of poly. 3. Waste water from the shower must be filtered and discharged to a sanitary sewer or a septic system. Decontamination Unit K. HEPA Filtered Negative Pressure System: negative pressure must be established and maintained in all containments to reduce the potential for airborne asbestos fibers to escape the work area. Negative pressure is established by installing HEPA filter equipped air filtration devices in the work area and exhausting the air flow outside of the building. These devices must be capable of exchanging the air in the work area at least 4 times per hour and achieving a negative air pressure of The ventilation system that must operate from the time of initial asbestos disturbance until the containment passes final air clearance testing. 1. The negative air machine must be equipped with a calibrated pressure gauge, audible alarm and/or and automatic shutdown mechanism if unit is not operating properly. 2. Must maintain a negative pressure inside the containment of 0.02 inches of water. 3. The negative pressure must be measured by a recording manometer placed as far from the intake of the negative air units as possible. Negative Air Units 4. The manometer must be calibrated annually and zeroed before each shift. 5. The filtered air from the negative air units must be exhausted outside the facility. L. Removal of Asbestos-Containing Materials: Prior to removal, all materials must be sufficiently wetted using water to which a surfactant has been added. All asbestos-containing material must be removed in the following manner: Page 4 of 6

5 1. The ACM is adequately wet before and during removal and immediately placed in sealed containers while wet to prevent drying. 2. Objects covered with ACM are removed intact or in large sections, wet before being sealed in clear six-mil poly and lowered to the ground, not dropped. M. Completion of Abatement: after ACM removal the interior surfaces of the containment and decontamination unit must be cleaned as follows: 1. Cleaning is performed using HEPA vacuum and wet-wiping methods until all visible dust and debris have been removed. 2. All removal equipment is cleaned or sealed in two layers of six-mil poly before removal from the containment. 3. All ACM waste must be removed from containment. HEPA Vacuum 4. Following postabatement cleaning a visual inspection of the containment and decontamination unit is conducted. If any residue in observed the cleaning sequence is repeated until the area passes the visual inspection. 5. After passing the visual inspection the containment is encapsulated using a post abatement lockdown encapsulant. 6. When the encapsulant has completely dried, the containment floors and walls are removed and sealed in leaktight containers. All critical barriers remain in place. 7. Following removal of the walls and floors of the containment all surfaces in the containment are re-inspected and the entire area recleaned if any suspect debris is observed. 8. Clearance air sampling is performed by a State certified individual and meets the requirements of state and/or federal air sampling rules. Once the containment passes the visual inspection and the aggressive clearance air sampling, all critical barriers and the decontamination unit are taken down and disposed of as ACM waste. 9. A final visual inspection is conducted in the containment area. If any debris or residue is observed the work area is re-cleaned and another set of Page 5 of 6

6 clearance air samples collected. This process is repeated until the containment area passes both visual inspection and clearance air sampling. 10. The HEPA filtered negative pressure system is shut off. N. Replacement of HVAC System Filters: At the completion of the abatement project the interior surfaces of the ventilation system is visually inspected and if suspect ACM dust or debris is identified the entire system is decontaminated. 1. All disposable HVAC system filters that serve the work area are replaced at the conclusion of the project and disposed of as asbestos waste. O. Waste Handling Procedures: All asbestos-containing waste is adequately wetted and must be handled on-site as follows: 1. ACM waste with sharp edges is placed in metal or fiber drums with locking ring tops. 2. ACM waste without sharp edges is placed in clear, correctly labeled sixmil poly bags. Each bag must be goose-necked and sealed to prevent leakage. Each bag is then placed into a second bag which is again goosenecked. Labeled Asbestos Waste 3. All containers are labeled according to DOT, OSHA and NESHAP requirements including waste generator identification. 4 All waste is removed through the decontamination unit or waste load-out unit and disposed of at an EPA approved landfill. Page 6 of 6