Rosie is getting her teeth cleaned.

Like a pair of industrial dentists with water and steel picks, Mike Haden and John Chesser took jack hammers and pressure washers to the giant tunnel boring machine’s drill bits Wednesday to dislodge 10 months of caked on soil and rock. The 300-foot-long, $12 million machine with a 30-foot-6-inch-tall head chewed through a drop shaft southwest of Exchange and Main streets last week.

Her massive tunnel job under Akron is (nearly) done.

In the next few weeks, workers from the company that controlled her — Kenny Obayashi — and the joint construction management team of Parsons, Welty and Thomarios will crawl between her gears and pistons to cut and dissemble the modern marvel. If all goes as planned, a shiny red crane that can lift 300,000 pounds at a time will hoist her first pieces out of the earth in October.

With a background in industrial pipe laying, Mark Strong of Goodyear Heights has labored for four years on the city’s $1.1 billion combined sewer overflow project — called Akron Waterways Renewed! He explained Wednesday on a tour of the drop shaft that, by the end of the week, Rosie will be slid forward about 8 feet along narrow steel plates lining a pair of 30-foot-long concrete railings, each a couple feet thick.

Rosie will place the last sections of concrete wall that form the sides of the city’s new 6,240-foot-long storm overflow trunk. In the average year, the tunnel and the dozens of pipes that connect it to new and existing sewer systems should keep 450 million gallons of mixed rain and sewage from spilling into the Ohio and Erie Canal and Little Cuyahoga River. The Ohio Canal Interceptor Tunnel alone has the capacity to capture 26 million gallons during heavy rainfall and send it north using gravity to be processed at the city’s sewage treatment facility in the Cuyahoga Valley National Park.

The 45-foot-wide shaft visible from the Main or Cedar street bridges or the bar patio at 69 Taps will be tied into sewer systems that collect waste from the east along Exchange Street, south along Wolfs Ledges and in the immediate area around the hole. Other drop shafts along the tunnels northern path will pull in water from as far as Mud Run.

When work on the nearby racks 16, 17 and 38 are complete, Project Manager Mike Witrzyszczewski said some existing sewage lines will be cut so flow can be diverted to the new tunnel .

"It’s just a sequence of events that has to happen in a certain order," he said of the process.

When finished in a year, Akron’s gray water will flow into the drop shaft, gently cascading off baffles to prevent an otherwise 166-foot-tall waterfall from eroding the pit’s bottom.

Reach Doug Livingston at 330-996-3792 or Follow him @ABJDoug on Twitter or on Facebook.