Home darkrooms have been around for many, many years, all over the world. Considering that, one might find plenty of cases of harm to sewage disposal and septic systems and the environment from home darkrooms, if it actually does happen. Does anyone know of any actual cases where harm to a sewer system or septic system has been attributed to photographic solutions being poured down a drain from a small, home darkroom? Or harm to the environment or groundwater?