What is infiltration in a sewer system?

What is infiltration in a sewer system?

• A. The seepage of groundwater into the sewer system, potentially causing system overload
• B. The entry of rainfall runoff directly into the treatment plant
• C. The loss of sewer gas to the atmosphere
• D. The process of sediment removal in primary treatment

Answer: (A)

Infiltration means groundwater seeping into the sewer system through cracks and defects in pipes, joints, manholes, and service connections. This adds water to the sewer that isn’t part of the wastewater, so the flow through the system increases even without rain. That extra volume can overload pipes and pump stations and raise the amount of water that must be treated, potentially leading to overflows or backups if the system is near capacity. This is different from inflow, which is rainfall or runoff entering the sewer directly, often during storms. It’s also not about sewer gas escaping to the atmosphere, nor about removing sediment in primary treatment. Infiltration specifically refers to groundwater entering through leaks and defects.

Infiltration means groundwater seeping into the sewer system through cracks and defects in pipes, joints, manholes, and service connections. This adds water to the sewer that isn’t part of the wastewater, so the flow through the system increases even without rain. That extra volume can overload pipes and pump stations and raise the amount of water that must be treated, potentially leading to overflows or backups if the system is near capacity.

This is different from inflow, which is rainfall or runoff entering the sewer directly, often during storms. It’s also not about sewer gas escaping to the atmosphere, nor about removing sediment in primary treatment. Infiltration specifically refers to groundwater entering through leaks and defects.