What does I/l stand for in collection system terminology?

The term "I/I" stands for "Inflow and Infiltration." This terminology is crucial in collection systems as it refers to the two primary causes of excess water in sanitary sewer systems.

Inflow refers to stormwater that enters a sewer system directly from sources like surface runoff, downspouts, or street drains during wet weather. Infiltration, on the other hand, describes groundwater or rainwater that seeps into sewer pipes through cracks or joints in the infrastructure.

Understanding I/I is essential for wastewater management, as both inflow and infiltration can lead to overwhelmed systems, increased treatment costs, and potential environmental damage. Properly managing I/I helps maintain the integrity and efficiency of the collection system, ensuring that wastewater is processed appropriately without unnecessary dilution from extraneous water.

The other options do not correctly describe the terms associated with collection systems, leading to confusion about the nature of water contributors to the system. Inappropriate terminology would not capture the critical dynamics involved in managing wastewater flows effectively.