QUESTION: Why care about something like plastic microbeads?ANSWER: The starting point in any discussion about the life span and effectiveness of individual sewage treatment systems is making sure effluent coming out of the septic tank does not exceed about 160 mg/L BOD and 60 mg/L suspended solids. When BOD levels are consistently above 160 mg/L and certainly over 200 mg/L, it is common to recommend additional pretreatment to reduce the levels before discharge to the soil for final treatment and dispersal. This keeps biomat development in check and within the long-term acceptance rate parameters for soil. At these levels, it
