Sewer / Biological Treatment Systems
Most photographic processing effluents and wash waters contain chemicals that are biodegradable. They are, therefore, compatible with aerobic (with oxygen) biological treatment systems and are effectively treated when sent to an efficient sewage treatment facility. Permission from the local treatment authority may be needed (a written consent or permit is usually needed and limits what can and can't be discharge). Contact your local authorities to see
if you need consent and to determine local discharge limits.
Kodak strongly recommends that you never pour silver-bearing effluents such as used fixers,
bleach-fix or stabilizers down the drain. Rather you should use on-site or off-site silver recovery.