I have seen the BOD of one water treatment poly listed as 24000mg/l. Others are listed as slightly or non-biodegradable.
Regards
TerryF
http://www.valorebooks.com/Search/ISBN/1893664031
My biggest concern (at least not sludge yet) is that operators do not realize how toxic some of these can be and that they can impart toxicity to effluent at the same time they take it out.