Torn Suit, Backwards Runoff, and a Storm Drain at a Dry Cleaner
The exclusion zone at an abandoned dry cleaner is defined by survey tape strung between rebar stakes. The contamination reduction zone has a three-step decon line: a wash with a garden sprayer, a rinse with a second sprayer, and a clean change area under a pop-up tent. The pad is graded so runoff flows away from the tent, but recent rain has cut a channel that sends water past the tape and toward the site entrance. At 14:20 a worker snags his Tyvek suit on a rebar stake, tearing a 6-inch hole at the left knee; he has about three hours left on shift and a full set of samples to collect. Two other workers are washing boots in a plastic tub and dumping the wash water into a storm drain at the curb, saying it is just soap. The site safety plan specifies Level C with organic vapor APR, and the dry cleaner's back door has not been opened since the investigation. A supervisor tells you to send the worker back in, because perchloroethylene is only a probable carcinogen, not an acute poison.
1. Identify the site control and decontamination deficiencies and state the correction for each.
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Several separate failures, and they should be fixed before another entry.
Boundary: survey tape on rebar is not a barrier - it stops neither a delivery truck nor a trespasser, and the rain channel is a physical breach routing contaminated runoff out of the CRZ toward the site entrance. Replace the tape with fencing or rope and signage at every approach, and re-grade or berm the pad so all runoff collects inside the CRZ in a sump or wading pool.
Decon line: the sequence is sound on paper - wash, rinse, remove outer PPE, then remove inner gloves and respirator last in the clean area - but the runoff direction is backwards and the pad is unlined. Put a containment basin under each step and a step-off at the boundary.
Housekeeping: the torn suit, the boot-wash tub dumped to the storm drain, and the unopened back door all need attention, and the CRZ needs a marked clean/dirty line so nobody re-enters without passing through it.
2. The worker has a 6-inch tear at the knee and wants to finish his samples. What is your decision and the correct procedure?
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He does not go back in that suit. A 6-inch tear at the knee is a breach that lets contamination reach the leg and inner clothing, and once contamination is inside the suit the wearer is being dosed for the rest of the shift. The supervisor's framing is backwards: the chronic hazard is precisely the reason not to accept a dermal dose, and perchloroethylene is also a CNS depressant with acute effects at high concentration.
Procedure: exit through the decon line as a contaminated worker, complete the wash and rinse, then remove and bag the suit as contaminated waste. Survey the knee area - if inner clothing is wet or the survey shows contamination, he needs a full shower and a change of clothes, and the exposure goes on the site record. If he re-enters, it is in a new suit, after the tear cause is fixed by capping or pulling the rebar stakes, and the HSO authorizes re-entry, not the supervisor who wants the samples.
3. Coworkers are dumping boot-wash water into a storm drain. Explain why this is not acceptable and describe correct handling.
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'Just soap' is wrong. The tub is used to wash boots that have been in the exclusion zone, so the water carries perchloroethylene at whatever concentration came off the boots. PCE is a listed solvent and a probable human carcinogen, and a storm drain discharges untreated to a creek or ditch - a discharge of a pollutant under the Clean Water Act, and potentially a reportable release depending on quantity and state rules.
Stop the dumping, contain the tub, and containerize the wash water as investigation-derived waste. Characterize it by sampling or by the site waste profile, then dispose through the site's waste contractor. The decon pad itself should be a lined, bermed area with a sump, and wash water from the entire line should be collected as waste rather than allowed to run off. Retrain the crew on the difference between the sanitary sewer and the storm sewer, and document the corrective action in the site log.