Typical BOD and suspended solids (SS) concentrations for domestic wastewater average approximately what range in mg/L?

Typical BOD and suspended solids (SS) concentrations for domestic wastewater average approximately what range in mg/L?

• A. 50-100
• B. 300-350
• C. 400-450
• D. 200-250

Answer: (D)

BOD and suspended solids show how much organic loading and particulate matter are present in wastewater. In typical domestic wastewater entering a treatment plant, these concentrations are commonly around two hundred milligrams per liter, with BOD around 200 mg/L and suspended solids in a similar range (roughly 150–250 mg/L). The range 200–250 mg/L best reflects this average for untreated domestic wastewater. The other options are not representative: they are either too low for domestic influent or exceed what is normally observed, which would suggest stronger industrial inputs or unusual dilution.