8.3 Final Clean-Up, Visual Inspections & Clearance Air Testing (PCM and TEM)

8.3 Final Clean-Up, Visual Inspections & Clearance Air Testing

Quick Answer: Final clean-up proceeds as follows: wet-clean and let dry, then a pre-sealant inspection, then sealant on stripped surfaces and poly, then remove wall and floor poly while keeping critical barriers, then wet-clean twice, then a clean-up inspection, then aggressive clearance air sampling. Only after passing results are critical barriers removed, followed by a final inspection and the Certificate of Completion. Clearance is by TEM (AHERA criteria: an average of 70 s/mm² or less, or passing the Z-test) for most subcode and larger projects. PCM clearance (each sample 0.01 f/cc or less) is allowed for small licensed jobs and for subcode glovebag and encapsulation projects.

Visual Inspection Comes First

Air testing cannot make a dirty work area clean. The subcode ties each step to a visual check by the AST:

1. Pre-sealant inspection after stripping and scrubbing, to confirm all ACM has been removed before any sealant is applied (N.J.A.C. 5:23-8.7(b)3).
2. Clean-up inspection before critical barriers are removed. The area must be free of all visible dust, asbestos, and ACM, and all waste must be in a locked, secure container outside the work area (N.J.A.C. 5:23-8.7(c)).
3. Final inspection within 48 hours after critical barriers are removed, confirming no visible asbestos and proper off-site disposal (N.J.A.C. 5:23-8.7(d)).

Many specifications also cite ASTM E1368, a consensus practice for visual inspection of abatement projects, for detailed inspection methods such as bright lighting, checking ledges and hidden surfaces, and wiping suspect dust.

The Subcode Clean-Up Sequence (N.J.A.C. 5:23-8.15(g)-(h))

After stripping:

1. Scrub all surfaces from which ACM was removed with nylon or bristle brushes and wet-sponge them, keeping them wet with amended water or removal encapsulant.
2. Package disposable equipment. Wash containers and remove all exterior particulate before they leave the contaminated area. Move accessory equipment to the equipment room for decontamination.
3. Retrieve all free water. Add it to the waste, seal it in plastic-lined leak-tight drums, solidify it, or pass it through a 5-micrometer filter to the sanitary drain if the local treatment works allows.
4. Final clean-up step 1: Mist all surfaces with amended water or removal encapsulant, wet-wipe with disposable cloths, and let everything dry. Then request the pre-sealant inspection in writing.
5. Step 2: After a satisfactory pre-sealant inspection, spray a sealant on all dried exposed surfaces where ACM was removed and on the poly covering walls, floors, and fixtures. The sealant must be a color distinct from the substrate.
6. Step 3: Carefully remove the wall, floor, and fixture poly, rolling it contaminated side in, and bag it with tape and debris as asbestos waste.
7. Step 4: Wet-clean all surfaces, let them dry, and repeat.
8. Step 5: Spray the critical barriers with encapsulant but do not remove them until air monitoring gives satisfactory results.
9. Step 6: Request the clean-up inspection and final air clearance monitoring.
10. After passing: Remove and bag the critical barriers, wash the inside of windows, and repair anything damaged. Then request the final inspection and apply for the Certificate of Completion.

Aggressive Air Sampling (N.J.A.C. 5:23-8.21(c))

• Timing: Within 48 hours after clean-up, before removing critical barriers, perform a thorough visual inspection and the final air test. Surfaces must be completely dry, and air-filtration units keep running during sampling.
• Leaf blower: Before sampling, sweep floors, ceilings, and walls with the exhaust of a one-horsepower leaf blower, including dead-air areas. Do not use one on open dirt, sand, or gravel floors.
• Fans: At least one fan per 10,000 cubic feet of work area, capable of at least 500 feet per minute, with airflow directed toward the ceiling and placed so it does not interfere with the samplers.
• Sampler placement: Pumps and media are placed randomly for unbiased, representative samples.
• Housekeeping: Keep the area free of non-asbestos debris that would make aggressive sampling impractical.

The AHERA method (Appendix A to 40 CFR 763 Subpart E) uses the same approach. Primary containment poly is removed and the area has dried and passed visual inspection, but barriers over windows, doors, and air passageways stay in place until TEM results meet the criteria. Air-filtration units stay on. Surfaces are swept with a one-horsepower leaf blower. One stationary fan per 10,000 cubic feet blows toward the ceiling. Pumps run at 1 to 10 L/min for 25-mm cassettes, at randomly selected sites.

Which Analysis and Which Pass Criteria?

PCM Clearance

• Pass: every sample is 0.01 f/cc or less. There is no averaging. One sample at 0.011 f/cc fails. A sample at exactly 0.010 f/cc passes.
• PCM is fast and inexpensive but counts non-asbestos fibers too, so a dusty area can fail even after good asbestos removal.

AHERA TEM Clearance (40 CFR 763.90(i) and Appendix A)

• Sample set: At least five inside samples and five outside (ambient) samples collected at the same time, plus field blanks and a sealed blank (the usual set is 13 cassettes).
• Volume: Enough air for the required sensitivity. Appendix A sets minimum volumes of about 1,199 L for a 25-mm filter and 2,799 L for a 37-mm filter to use the initial screening test.
• Initial screening test: If the average of the five inside samples is 70 structures per square millimeter (s/mm²) or less, and adequate volumes were collected, the response action is complete.
• Z-test: Otherwise, compare inside with outside using the Z-test. The action is complete if Z is 1.65 or less, meaning the inside average is not statistically greater than the outside average. If Z is greater than 1.65, the area fails and must be re-cleaned and resampled.
• Blank check: High counts on blanks can invalidate a sample set. The laboratory must report blanks, and contamination problems must be resolved.

When Clearance Fails

The subcode requires clean-up to be repeated until compliance: re-clean all surfaces with wet methods while all HEPA air-pressure differential units run, then resample (N.J.A.C. 5:23-8.21(h)). Critical barriers stay up. Under the license rules, the licensee must correct violations of its performance standards at no additional charge to the customer (N.J.A.C. 12:120-4.7(d)). Contracts usually specify who pays for repeat testing (Section 10.2).

Certificates and Reoccupancy

On subcode projects:

1. After a satisfactory final inspection, the owner or agent applies within five days of completion for a Certificate of Completion.
2. The ASCM issues it only if the final inspection shows no visible asbestos and acceptable final air results are documented in writing.
3. The enforcing agency then issues the Certificate of Occupancy. Reoccupying a vacated area before then is unlawful (N.J.A.C. 5:23-8.8).

Exam Traps

• Critical barriers stay up during clearance. Wall and floor poly comes down before clearance; critical barriers come down after passing results.
• Sealant timing: Sealant is applied only after the pre-sealant inspection, and it must contrast in color with the substrate.
• PCM pass mark: "Less than or equal to 0.01 f/cc" for each sample.
• TEM thresholds: An average of 70 s/mm² or less, or Z of 1.65 or less.
• Fans: One per 10,000 cubic feet, aimed at the ceiling.

Scenario

Acoustical plaster (800 sq ft) is removed from a high school library, a subcode project.

• After scrubbing and wet wiping, the AST's pre-sealant inspection finds residue on beam flanges. The contractor re-cleans, and the AST accepts in writing.
• Contrasting-color sealant is applied. Wall and floor poly is rolled up and bagged. Surfaces are wet-cleaned twice. Critical barriers are encapsulated but left in place.
• The AST performs aggressive sampling: leaf-blower sweep, then two fans for the room's 18,000 cubic feet, aimed at the ceiling. Five inside and five outside TEM samples are collected with blanks.
• The laboratory reports an inside average of 54 s/mm² with adequate volumes, so the area passes on the initial screening test.
• The AST authorizes barrier removal in writing. Within 48 hours after barriers come down, the AST completes the final inspection. The ASCM then issues the Certificate of Completion, and the construction official issues the Certificate of Occupancy.