Which statement best describes infiltration?

Which statement best describes infiltration?

• A. Water entering through roof drains
• B. Water that seeps into joints and cracks from surrounding soil
• C. Water from leaks inside the building plumbing
• D. Water that leaves the sewer system

Answer: (B)

Infiltration is groundwater that seeps into the sewer system from the surrounding soil through cracks and joints in pipes or manholes. It happens because water in the surrounding soil and groundwater can push its way into the sewer as it encounters openings, especially in older or damaged pipes. This is different from water entering the sewer from inside the building or from surface runoff. The statement about water entering through roof drains describes inflow, which is surface water or stormwater that directly enters the sewer system through connections like downspouts or roof drains. Water from leaks inside the building plumbing is wastewater generated inside the building and discharged into the sewer, not groundwater seeping in. Water that leaves the sewer system describes exfiltration or other outflow, not infiltration.

Infiltration is groundwater that seeps into the sewer system from the surrounding soil through cracks and joints in pipes or manholes. It happens because water in the surrounding soil and groundwater can push its way into the sewer as it encounters openings, especially in older or damaged pipes. This is different from water entering the sewer from inside the building or from surface runoff.

The statement about water entering through roof drains describes inflow, which is surface water or stormwater that directly enters the sewer system through connections like downspouts or roof drains. Water from leaks inside the building plumbing is wastewater generated inside the building and discharged into the sewer, not groundwater seeping in. Water that leaves the sewer system describes exfiltration or other outflow, not infiltration.