DigIndy wastewater tunnels nearly done after more than a decade of work

By: Taj Simmons

INDIANAPOLIS — How often do you think about where your water goes when you flush the toilet or run your sink? Citizens Energy Group has spent more than a decade making sure that water does not end up back in nature.

The DigIndy sewer overflow project created nearly 30 miles of wastewater tunnels deep beneath Indianapolis, beginning in 2012. The last tunnel work should finish this year, but the system has already diverted more than 7 billion gallons of wastewater to treatment facilities.

"It's daunting," said Citizens Energy Group Engineering Manager Mike Miller. "If you think about what a 5-gallon bucket looks like from Home Depot, and pour that on the ground, think about what 7 billion would look like."

Before the project, treated sewer water overflow would end up in the White River in heavy storm events. The new tunnels were needed to meet Environmental Protection Agency standards.

Sewer water overflow now uses DigIndy tunnels separate from storm water and is treated in its own pumping stations.

"Go home and don't flush your toilets for three days. That will tell you the type of work we have to do every day to keep the city running," Miller said. "Very quickly you'll understand just how many people we have and what kind of infrastructure is needed to keep us a civil society, honestly."