Question 1

What is a CSO (Combined Sewer Overflow)?

Accepted Answer

When a combined sewer system (carrying both sewage and stormwater) overflows during heavy rain, discharging untreated wastewater directly into waterways. This is one of the primary problems smart sewers address.

Question 2

What is an SSO (Sanitary Sewer Overflow)?

Accepted Answer

Overflow from a sanitary-only sewer system, typically caused by blockages, pipe breaks, or infiltration. Unlike CSOs, SSOs are never expected and usually indicate system failure.

Question 3

What is RTC (Real-Time Control) in sewer systems?

Accepted Answer

Automated system that adjusts valves, gates, and pumps based on live sensor data to optimize flow distribution across a sewer network. The core technology behind most smart sewer deployments.

Question 4

What is SCADA in wastewater management?

Accepted Answer

Supervisory Control and Data Acquisition — an industrial control system architecture for monitoring and controlling water/wastewater infrastructure. Smart sewers typically integrate with or modernize existing SCADA systems.

Question 5

What is I&I (Inflow and Infiltration)?

Accepted Answer

Stormwater (inflow) and groundwater (infiltration) entering sanitary sewer systems through cracks, deteriorated joints, and illegal connections. A major cost driver that smart monitoring helps identify and quantify.

Question 6

What is NPDES?

Accepted Answer

The National Pollutant Discharge Elimination System — the EPA permit program regulating point-source discharges into US waters under the Clean Water Act. Smart sewer systems help utilities achieve and maintain NPDES compliance.

Question 7

What is a Digital Twin in sewer management?

Accepted Answer

A virtual replica of a physical sewer system that runs real-time simulations using live sensor data. Enables 'what-if' scenario testing and predictive failure analysis.

Question 8

What is IoT in smart sewers?

Accepted Answer

Internet of Things — a network of sensors and devices embedded in infrastructure that transmit data wirelessly. In smart sewers, IoT sensors measure flow, level, water quality, and gas concentrations throughout the network.

Question 9

What is Green Infrastructure for stormwater?

Accepted Answer

Nature-based stormwater management approaches including rain gardens, permeable pavement, bioswales, green roofs, and constructed wetlands. Often combined with smart gray infrastructure for optimal results.

Question 10

What is a Consent Decree in wastewater?

Accepted Answer

A court-ordered agreement between the EPA and a municipality requiring specific actions to address Clean Water Act violations, typically mandating infrastructure investments. Smart sewers can reduce consent decree costs by 50-95%.

Smart Sewer Glossary