You REALLY should be more concerned with the LOSERS at BP for destroying the worlds oceans and not so much with the water used by rinsing film or prints.
We in the USA pay a MAJOR amount for Water and Sewer processing and the amount of stuff that goes in the sewer is NOTHING compared to what goes down the drain just in household cleaners and washing cloths etc, So we PAY for this use and what we are depositing is a drop in the bucket.
And if you are REALLY freaked out, go buy some carbon offset credits (http://www.carboncatalog.org/) to off set your hazardous waste activity !!
Now you will be SUPER GREEN !!!