Combating I&I With Sensor Technology

Hampton Roads Sanitation District is using flow monitoring to help get inflow and infiltration (I&I) out of the sewers. Learn why this method will save the municipality millions versus alternative approaches.

Hampton Roads Sanitation District (HRSD) in Virginia Beach, VA, is a regional wastewater authority with nine plants treating a total of 150 to 200 MGD. During rain events, however, the flow can become unmanageable. HRSD and the U.S. EPA both agree that inflow and infiltration into the sewers needs to be addressed. Phil Hubbard, HRSD’s special assistant for compliance assurance, talked with Water Online Radio about the district’s plan to resolve the issue with the help of flow monitors.

Hubbard explains the problem:

“When you design sanitary sewer systems, you design it per capita: 100 gallons per person per day, four people per household. You [design with] a peaking factor of two and a half … [and] we’re getting peaking factors of seven, 10, 12, 15.

“We need to get all that water out, so that we don’t have to pump it, convey it, and treat it. We try to get it out at the source. With the flow monitor that we’re using, that’s given us an idea of how much rainwater is getting in…

“If you had to convey all that water to the treatment plant, a treatment plant upgrade is about $150 to $200 million. Then you have to convey that water, so you’ve got to have bigger pipe. …It’s much cheaper to get it out at the source than it is to convey it all the way to the plant.”

Kraig Moodie, president of FloWav, was also there to discuss how the sensor technology is deployed and works within an integrated system to provide flow monitoring data and, ultimately, cost-effective solutions to I&I.

Hear the full details by tuning in below.