A population of 12,000, nearly 70 miles of sanitary sewer lines and 10 lift stations keep things pretty busy for the two-man crew that maintains the wastewater collection system in Marinette, Wis.

But in this era of outsourcing, the city’s Wastewater Utility has done something unusual. Instead of turning to outside contractors for video inspections of the sewer system, the city has taken the work in-house.

As a result, operations are far more efficient, says Roger Keller, the Wastewater Utility foreman in charge of the collection system. There is no more juggling of appointments, no telephone tag with contractors, and no more delay in having to schedule an outside contractor to re-inspect lines that require repeated cleanings.

“We’re really happy with it,” Keller says.

Step by step

Until a few years ago, when the city needed a video inspection, it had to hire a contractor. That proved to be a recurring challenge. It meant juggling schedules with the contractor, and it also meant significant “do-over” work.

“A lot of times we’d be cleaning the mains for televising, and when the video crew came in, they weren’t clean enough,” Keller says. His crew then had to go back and clean again, then bring the video contractor back.

Marinette moved away from that arrangement step by step. In 1995, the city purchased a Predator 2 mini-camera system made by UEMSI. This portable push camera system for 3- to 12-inch lines includes more than 200 feet of cable. It is used strictly for inspecting laterals.

It was especially useful for helping the city sort out when sewer line problems were the city’s responsibility, and when they fell to the customer. When homeowners complained of a backup, the city crew could quickly investigate with the camera equipment. “We normally would go in right from the cleanout to the main to determine what the problem was,” Keller says. “Then we were able to tell the homeowner whether the problem was theirs or ours.”

Still, the small size of the camera limited its use, and contractors were needed to inspect the main sewer lines. But another city department took interest in the city’s new-found video-inspection capability.

Moving up

“Engineering was always asking us if we could TV this line or that line,” says Keller. “We could not do that with that little camera we had.” So, in 2003, the city upgraded, purchasing a Predator Advantage mini-mainline camera, with 500 feet of cable and a power rewind.

In 2004 the city upgraded the power control unit and added a UEMSI Trax transporter — a crawler with treads to use with the Predator Advantage. Like the Predator 2, it looks only straight ahead, but the transporter allows the Marinette crew to drive it through 6- to 12-inch lines to distances of up to 500 feet.

The engineering department’s demands weren’t the only reason for the new camera: The city was unhappy with the work of an inspection contractor. After buying its own mainline camera, the city stopped using contractors for most main inspections.

Today, outside contractors perform inspections only when the city is putting in a new sewer line. That’s because the inspection is part of what the city requires when it contracts for sewer line installations. “That’s all incorporated in their bid,” Keller explains.

A new look

The mainline camera quickly proved its value, and not just for post-cleaning inspections. “Engineering loves this camera,” Keller says. “There are a lot of times where engineering just wants to see the condition of the line for an upcoming project. They usually want these things videotaped first to verify everything on them.”

Out comes the camera. Information from the inspection is turned over to the engineering department, which adds the data to existing maps of the system. A recent post-cleaning inspection offers a typical example of the system’s broader benefits.

A crew cleaned about 600 feet on Main Street. The next day, Keller set up the video inspection. “We had cleaned this really well, but when we went in 208 feet, we found a brick in there, and we couldn’t go any farther. We had to go back in and get that out of there.”

It’s a perfect illustration of what the city doesn’t know about its system. “We turn this information over to engineering so they can put it on their mapping,” Keller says. “On some streets, there has never been any information, other than it’s, say, a 12-inch clay main,” Keller says. To date, the city has inspected about 10 percent of its system.

On another sewer line inspection, the crew used the video equipment to detect a groundwater infiltration of 10 gpm. “Without videotaping that area, they would have just assumed it was all right,” Keller says. The information moved that segment of line up on the city’s priority list for replacement. This section was then replaced in conjunction with an interceptor replacement project.

Storm sewer applications

Keller’s department is responsible only for sanitary sewers, but the cameras are called on for other work as well. The crew routinely gets borrowed to investigate the city’s storm sewer system.

“The City of Marinette has extensively replaced the main storm interceptor lines,” Keller says. “There are a lot of older ones.” Videotaping has become an important step in ensuring that the new lines are doing the job and in deciding which old lines will be the next scheduled for replacement.

In 2006 the city upgraded again, purchasing a Navigator DVD Ultra system from UEMSI. The system includes a camera with a self-leveling head that automatically keeps the picture upright. The camera fits in pipe as small as 2 inches.

The new camera allows the city to record directly to DVD. Better still, because it is compatible with the city’s older mainline camera, the Navigator makes it possible to convert older videotapes to DVDs for playback and storage.

In early 2007, the city purchased a Cobra Technologies camera through UEMSI. Now, for the first time, the city has pan, tilt and zoom capability in a camera that can look as far as 20 to 30 feet up a line. The city also replaced its track-based crawler with a Prowler wheeled transporter from UEMSI. Keller likes the wheeled transporter for its interchangeable wheels and because the design offers excellent traction.

Doing it all at once

The backbone of Marinette’s sewer-cleaning operations is a Vactor 2100 series combination truck equipped with a positive displacement pump and a front-mounted jetter. The truck is rated at 80 gpm.

Keller and his co-worker, Gary Kmiecik, routinely clean and televise at the same time. To do this, the two crewmen position themselves at successive manholes. The man with the jetter extends it into the first manhole and up to the second. Then, as the jetter operator begins to withdraw the jetter back to the first manhole, the camera operator runs the camera into the second manhole and “chases” the jetter out.

The procedure requires both workers to be especially careful so that the cameras aren’t damaged, but it saves time and allows the crew to be sure in real-time that the sewer is being thoroughly cleaned.

All in all, Keller is sold on Marinette’s decision to do its own camera work. “It gives us the freedom to go ahead and start a project, clean it out, get that camera there, and see what’s going on,” Keller says. “It gives us a definitive answer as to what’s going on.”