When adding a disposal unit to a kitchen and septic system, what do you expect to see an increase in?

When introducing a disposal unit to a kitchen and septic system, an increase in Biochemical Oxygen Demand (BOD) is expected. BOD is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water. A disposal unit typically grinds and flushes down food waste and other organic materials into the septic system. This additional organic load can lead to higher BOD levels because the bacteria in the septic tank will need more oxygen to break down the increased quantity of organic material.

Elevated levels of BOD can indicate that more organic matter is being introduced into the system, which can strain the septic system's capacity to treat waste efficiently. This can potentially lead to system failures if the organic loading exceeds the system's design limits.

Other factors like total coliforms, nitrogen content, and phosphate levels may also change but are not as directly related to the immediate effect of adding a disposal unit in terms of organic loading. Total coliforms may rise due to food scraps, nitrogen levels may vary depending on specific food waste, and phosphate levels can also be influenced, but BOD clearly measures the direct impact of added organic material on the system’s operation.