Management of individual mechanical sewage-treatment systems: how much is needed?

Over 2,600 individual mechanical sewage-treatment systems were studied to determine if mandatory maintenance contracts and semiannual inspections with effluent sample collection are adequate to meet discharge standards. The following discharge standards were set: 20 milligrams per liter (mg/L) for five-day biochemical oxygen demand (BOD5), 20 mg/L for total suspended solids (TSS), and 400 organisms per 100 milliliters for fecal coliform bacteria. In 1997, 67 percent of the individual mechanical sewage-treatment systems discharging in Will County, Illinois, were in violation of at least one discharge standard. The overall cost of management, shared by the homeowners and the county health department, ranged from $350 to $725 per year.