Biological oxygen demand (BOD) measures the total organic content of water based on the consumption of oxygen in a sample at 20deg C Celsius over five days. A consumption of 10 to 20 mg of O2 per liter most likely represents a sample from

Biological oxygen demand is a measure of organic content in water. The greater the demand, the greater the load of organic content that can be broken down, reflecting a high bac-terial load. Untreated freshwater has a BOD of 25 mg/l, treated sewage, 10-20, domestic sewage, 200-500, and industrial sewage, >2000.