Inflow and infiltration (I&I) is a phenomenon whereby stormwater and groundwater enter the wastewater system. This water, which should drain into the ground or be routed to storm drains, can overload the wastewater system causing sewage overflows to creeks, backups in basements and impaired operations at the Roanoke Regional Water Pollution Control Plant.

The Western Virginia Water Authority (Authority) is committed to reducing sewage overflows at the Roanoke Regional Water Pollution Control Plant  and in the vast sanitary sewer collection system the Authority maintains. In fact, in 2005 the Authority entered into a formal agreement with the Virginia Department of Environmental Quality to reduce sewage overflows. This agreement calls for:

• The rehabilitation of the wastewater collection infrastructure, including replacement of faulty manhole covers and cracked or deteriorating sanitary sewer pipes;
• Renovations and expansions of the Regional Water Pollution Control Plant to treat a larger volume of wastewater; and
• Eliminating I&I from wastewater pipes on private property--both commercial and residential. 

The Western Virginia Water Authority created an I and I Policy to establish procedures for the removal of Inflow and Infiltration from private sources entering the Public Sewer System, enforce the sewer use standards arising from Article IV of Chapter 18 of the Roanoke County Code, Article III of Chapter 26 of the City of Roanoke Code, Commonwealth of Virginia regulations, and to protect public health and facilities from the actual or potential discharge of Inflow and Infiltration.

I&I Inspections

Authority staff inspects private properties in the service area to determine if I&I is entering the wastewater system from private connections. This free inspection is coordinated with area real estate agents at the time of transfer or sale of property. After a request is received, an inspection will be scheduled, and inspection results will be issued within five days of the inspection. If I&I defects are found, property owners will be required to take corrective action. 

Do you need an I&I inspection?

Real estate agents with questions about the inspection requirements or who wish to make inspection appointments may contact the Authority at (540) 283-8275 or by e-mail at i&i@westernvawater.org

Printable I&I Inspection Request Form - pdf version

Online inspection request form

What can you do to prevent I&I?

• Disconnect downspouts and sump pumps that are carrying stormwater and ground water into the wastewater system. Stormwater should be directed into a planted area of your yard.
• Make sure roots are not blocking wastewater pipes. Roots can block pipes and allow groundwater to seep into pipes.
• Keep sewer cleanouts securely capped.
• Don’t pour Fats, Oils or Grease (FOG) down the drain. As it cools, FOG hardens and blocks the pipes which can cause sewage to back up.

What else is the Authority doing to prevent I&I?

The Water Authority is proud to convey and fully treat 37 million gallons of wastewater every day. In order to maintain the sanitary sewer system and reduce sewer overflows, the Water Authority:
• Conducts routine repairs and updates to the 980-mile sewer collection infrastructure, including replacement of faulty manhole covers and cracked or deteriorating sanitary sewer pipes.
• Expanded and renovated the Roanoke Regional Water Pollution Control Plant in 2007. This work increased the capacity of the plant and allows more wastewater to be treated. Additional renovations were completed in 2015.
• Conducts an ongoing Collection System Evaluation Study (CSES). The CSES pinpoints problems in specific sewer sheds, tracks wastewater volume carried by each sewer shed and monitors rainfall impact on each part of the system.
• Operates its own wastewater "detective agency," the Sanitary Sewer Evaluation and Rehabilitation (SSE/R) unit of the Wastewater Operations Division, to carry out the CSES and ensure day-to-day proper functioning of the system.
• Tests improvement scenarios using a computer model of the wastewater system. This process helps prioritize and ensure longevity and success of repairs.