Posted by Patrick on April 04, 2005 at 13:32:50:
In Reply to: How much cleaning? posted by jeff Shaw on April 02, 2005 at 12:41:05:
Jeff,
You ask "how much cleaning?"
In my view, more than is strictly necessary.
Cables and wiring that could ensnare the unwary diver, sure, they need to be pulled. Bunkerage (fuel) and other petroleum reservoirs, absolutely need to be pumped out. However, after a pump and a rinse, do these spaces need to be scrubbed clean? Probably not, but the rules mandate it. I'd guess that there is more petroleum product seeping naturally from Redondo Canyon or the Santa Barbara Channel area in any 2-hour period than would remain in the tanks of a Liberty or Victory ship.
Asbestos wraps for sound and thermal insulation? Again, mandated to be removed, but is pretty stable in the environment. Most commonly found as insulation material in engine-room spaces, but also in some adhesives and finishing materials. Underwater, it really becomes a moot point. Asbestos is a natural mineral. If it should slough off into the environment, it would not be in a form that would hazard humans, and it certainly wouldn’t be absorbed by sea life. The asbestos hazard occurs when it becomes friable and is inhaled (over a period of time). I know of some hard-core divers, but most aren’t inhaling (water) at depth. The cost of removing and disposing of asbestos is very high and would be a cost factor to consider on older ships
Lead Paint? I’m not sure how the lead content of paint would affect the environment. I would suggest that most wrecks, most natural rock reefs for that matter, accumulate more lead from lost fishing sinkers than what is carried in the paint coating of a reefed vessel. I'm also not clear as to how that might affect the sea-life in and on the wreck. There have been a few studies of toxin accumulation of life on artificial reef wrecks and accidental wrecks, and I can’t recall any mention of raised lead levels in the local critters. Unless they are actually nibbling on the paint I don’t believe lead contamination would be a problem either. Again, a big cost in the prepping of a artificial reef wreck.
PCBs, typically used as electrical insulation would have to be removed. But usually it is confined to specific equipment and not all over the ship as the lead paint and asbestos is.
So? Could two of the two most expensive substances that are targeted for removal be left in place. I believe so, but am willing to hear other point of view.
Stay wet.