How under (manhole) cover detectives sleuth their way through a sprawling sewer network

“You can flush anything, but that doesn’t mean it’s doing the sewer any favors,” said Joshua Dress, an Operation Technician with the Northeast Ohio Regional Sewer District’s Sewer System Maintenance & Operation (SSMO) department.

Part detective, part plumber, part cartographer, and a hearty mix of mind and muscle, SSMO crews have dirty jobs that would leave society in a bigger mess (literally) without them.

He and the other technicians work to clear out blockages that keep the District’s collection system from operating at full capacity and efficiency. “Many of times it’s rags that get caught,” Dress said. “Baby wipes, grit, debris. We’ve found cinder blocks.”

“I pulled a fender out once,” added Field Technician Brian Stapleton, Jr.

Some sewers in Cleveland date back to the 1890s and are still in use today. This 1982 photo of a sewer inspection shows similar safety precautions taken today.

The collection system carries wastewater and stormwater to the District’s wastewater treatment plants. After a heavy rain event, SSMO crews clean off the bar racks — giant screen-like structures located throughout the system that prevent large debris from reaching the treatment plant. “It’s a pretty intensive job,” said Stapleton. “After a rain event, you’ll see debris stacked all the way to the top of the bar rack.”

A JetVac is one of the large trucks that SSMO uses to keep the sewers clean. It has jet and vacuum systems and storage tanks for flushing out and removing debris. A tube put down a manhole takes debris out of the sewer, and the solids are taken to the District’s Southerly plant for proper disposal.

In addition, crew members physically inspect the tunnels. There are “3-team” tasks that entail lowering a technician from a tripod into a manhole while two operators assist on the surface, and “2-team” inspections that don’t require manhole entries. The 3-team routes take longer, due to the time required to set up the tripods and monitor the sewer atmosphere for hazards.

An ounce of prevention

Some locations are considered more critical to maintain than others, based on proximity to Lake Erie. “This regulator at East Park [in Cleveland’s North Collinwood neighborhood] has a side-spillway fixed weir,” said Dress during one particular site visit. “If that overflows, it’s going to go right into the lake.”

This large truck is known as a JetVac for its combination of a powerful water jet and vacuum tank for cleaning sewers and catch basins.

Preventative maintenance is central to SSMO’s work. In addition to inspecting and repairing the sewer infrastructure, crews inspect the District’s pump stations, controls, and monitoring equipment. While the field crews maintain, inspect, and repair the system’s fixed assets, the System Utility Maintenance Persons (SUMPs) maintain the automated assets: the electrical, mechanical, hydraulic, and pneumatic systems and instrumentation that regulate the flow of wastewater in the system, “basically everything that measures and keeps track of how the station is running,” said Dress.

The pros and the flow

There are three levels in the SSMO’s field crew department’s classifications: Field Tech Operators, Operator Technicians, and Field Technicians. “Op Tech is the next classification up from Field Tech, and requires a Commercial Driver License and Wastewater Collection Class 1 License,” said Dress. “Op Tech involves more paperwork, while Field Tech is more of the grunt work.”

Technology helps manage decades of sewer data

The SSMO teams benefit from having iPads with Geographic Information System (GIS) displays of all the Sewer District’s assets.

“These purple lines are sewer lines, and the yellow ones are the local lines,” explained Dress, pointing to a map on an iPad.

Details about an individual sewer — such as the pipe size and the year it was built — are easily accessible. “It makes it a lot easier to locate things and determine which lines are the Sewer District’s and where our responsibilities are.”

Work orders are created in the Oracle Work and Asset Management (WAM) system. Some are automatically generated, for example, in the event of a dry-weather sewer overflow, which is often caused by some sort of blockage. “In that case, WAM will indicate a need for a camera inspection, too,” said Dress.

Inspection, protection, and detection

Some jobs are bigger than others. “Straightforward preventative maintenance jobs might take an hour,” said Field Tech Operator Pete Lehman. “But if there’s a pipe that’s extremely dirty, we could be there for a week.”

This backflow preventer ensures flow only moves in one direction.

In addition to making sure the sewer pipes are clear of debris, SSMO inspects different underground structures, such as regulators and Tideflex backflow preventers that prevent river inflow during heavy rains.

In general, SSMO handles the District’s big interceptors pipes and combined sewer overflow infrastructure, while the City of Cleveland’s Division of Water Pollution Control handles the local sewers.

“It takes a while to see everything we deal with,” Dress said. “Even after being here a year, I still see sites that I haven’t come across on a route book.”

This story is excerpted from our Clean Water Works technical magazine. Michael Uva is Senior Communications Specialist at the Northeast Ohio Regional Sewer District.

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