All Aboard

In a small city with a big I&I problem, an all-out education program led the city council and residents to support system rehab and in-house equipment upgrades
All Aboard
Collections manager Josh Quesenbery cleans a manhole using a Vactor truck in advance of a confined-space entry. (Photography by Shannon Lee Zirkle)

Interested in Inspection?

Get Inspection articles, news and videos right in your inbox! Sign up now.

Inspection + Get Alerts

The City of Aberdeen lies about half an hour north of Baltimore. Founded in 1892, the wastewater system is a patchwork of upgrades subject to vicious bouts of inflow and infiltration (I&I).

Encouraging buy-in from the city’s administration and citizens about the need for action, the Department of Public Works has embarked on an aggressive plan to rehabilitate the system. In a little more than three years, the system has turned the corner.

With a four-person maintenance crew and the help of outside consultants, the sewer system has been mapped with GIS coordinates, hydraulic modeling has been completed, and every manhole in the system has been inspected. The department is also embarking on an in-house grouting program.

Matt Lapinsky, director of public works, credits much of the drive behind the effort to Josh Quesenbery, who joined the department five years ago as a 19-year-old maintenance worker. Quesenbery hit the ground running, immediately looking for ways to improve the system.

“Josh brings a lot of fire and passion to the job,” he says. Lapinsky describes the sewage system by borrowing a line from the Johnny Cash song, “One Piece at a Time.”

“The main part is 200,000 feet of 8-inch vitrified clay, some Orangeburg pipe, and a lot of it is much older than that,” says Lapinsky. “It’s the great stuff that everybody in the I&I business loves. On the other hand, we have some pretty stringent regulations and design standards about what has gone in over the past 15 years.”


I&I a big problem

However, the newer lines have barely dented the I&I totals. A preliminary study of the system indicated that I&I often overwhelmed the wastewater treatment plant, which processes an average of about 1.9 mgd.

Quesenbery and Lapinsky took the study and began to leverage the data to seek funding for a more thorough investigation. First on the agenda was explaining to the city council what I&I was and how it was affecting the city’s infrastructure and water rates.

“You can’t go before the politicians and the public and preach the message of I&I remediation unless you have documentation and facts to back you up,” says Quesenbery. “We needed solid evidence. But you need to realize that you’re never going to convince a small municipality to do everything overnight. It has to be incremental.”

Since all of the department’s efforts are funded by water rates, buy-in from residents was also crucial. Education extended to city streets, where department crew members always take time to explain to residents what they’re doing and why it needs to be done. The department also produces a monthly newsletter aimed at resident education.

Quesenbery began to build on the I&I study by examining the infrastructure on an ad hoc basis in the older sections of town, whenever he could find the time. A 15-year-old trailer-drawn CCTV system wasn’t a lot of help. “I didn’t have a rigid plan at the time,” says Quesenbery. “I was just going out and popping off manhole covers and checking the lines.”


Taking it to council

Lapinsky made a direct pitch to the city council in 2008, presenting the findings of both the I&I study and staff observations. The department’s objective was to have the council authorize the purchase of a dedicated inspection van to collect further data.

“Matt and I did our homework and made up a PowerPoint presentation that included graphs, maps and actual photos taken by the camera system showing infiltration and root problems,” says Quesenbery. “We made it clear that these were problems in our own system, not just photos pulled from the Internet. I could tell them that this was a photo of the street they lived on. For budgetary reasons, it was not an easy sell.”

The council approved the request, though, and the department soon took possession of a 2008 Ford F-550 diesel truck with an Omni III Pan and Tilt Zoom Model 10-1650 camera from RS Technical Services, with pole and push-camera accessories.

“The camera truck was the fruit of our labor,” says Lapinsky. “At that point, Josh went from maintenance work to the person in charge of inspection and was promoted to collections system manager. The camera was a means to gather more information and formulate a more elaborate action plan.”

Quesenbery also took charge of a crew of three workers who perform a wide variety of functions, ranging from cleaning, inspection and root control to tap cutting, main replacement, manhole grouting and pipe lining. The department uses a dedicated Vactor 2100 combination unit on a Sterling chassis and an assortment of nozzles from KEG Technologies.


In-house, if possible

“We try to do as much work in-house as possible,” says Quesenbery. “We don’t need to reinvent the wheel and go to outside contractors if there’s already a wheel available right here.”

In October 2008, the department initiated a hydraulic model and flow monitoring study of the city. For the purposes of the study, they broke the city into nine distinct groundwater basins to see where I&I was worst.

The city contracted the local office of environmental engineering firm Stearns & Wheler GHD to prepare the hydraulic modeling. Rather than lease equipment, the council directly purchased a mix of a dozen Hach Sigma Model 910 and 920 flowmeters and 20 rain gauges by the same manufacturer from local rep firm North East Technical Sales of Harleysville, Pa. Insight software was used to analyze the data.

“We could see that three of the basins were in the worst shape, and we focused our repair activity on those,” says Lapinsky. “The data doesn’t lie. We can see what we’re doing cost-effectively, and flow metering is the most important part of that.”

Infiltration sources include leaking manholes, high groundwater entering the joints of vitrified clay pipe, and rainwater-derived I&I entering through holes and fractures in the clay. Exfiltration from storm drainpipes also allows rainwater to migrate through the ground to the sewers through open channels created by repeated water flow.

Quesenbery was actually looking forward to camera inspection of 34 storm drain inlets marked as suspicious during smoke testing, expecting to find significant sources of I&I there. The drains were actually in surprisingly good shape, indicating that further study was necessary.


A thorough map

In 2009, the department em-barked on a more thorough study that included GIS mapping em-ploying Real Time Kinematic satellite navigation, I&I quantification, manhole inspection, and a system smoke test. The study was funded jointly by the city and the Maryland Department of the Environment. The work was carried out by the Department of Public Works, Stearns & Wheler, and independent state agency Maryland Environmental Service.

While satellites worked from the sky, Quesenbery and his crew provided ground support, supplementing the study with visual inspection and CCTV service. The study uncovered a surprising cache of hidden infrastructure that had dropped off the city’s radar. “We found roughly 350 to 400 manholes we didn’t know we had,” he says. “We had to clear each one off and in some cases had to bring them back above grade.”

The study also showed that the wastewater treatment plant processed a peak of 6.93 million gallons over a 24-hour period that year, about 5 million gallons of it from I&I. The smoke study, testing about 80 percent of the system, revealed a surprising statistic: As much as half the city’s I&I originated on private property. In a mini-pilot program of 60 home inspections, the department found at least seven residences with sump pumps emptying directly into the sewer.


Private matters

“We believe that illegal connections and leaking clay laterals are a major contributor to I&I,” says Quesenbery. “We’re also finding roof and foundation drains going directly into the sewers. By removing these illegal connections, we believe we’ll be able to reduce I&I considerably.”

The biggest stumbling block to controlling private I&I is the municipal code, which isn’t clear on where municipal ownership of the lateral ends and private ownership begins. “I believe we need to strike some sort of balance here,” says Quesenbery. “For a member of a middle-income family, it’s not easy to be told you have to do something and it’s suddenly going to cost you this much. However, we do need to settle the question at the municipal level.”

A proposal that may allow the department to inspect the drainage systems of private homes is under study. The GIS mapping was completed in 2010, and it provided the ammunition for the department to make a pitch to city council for further repair and rehabilitation efforts.


In-house grouting

The study also determined that an in-house grouting program would be best for combating city infrastructure I&I cost-effectively. Quesenbery and Lapinsky used that recommendation to request the funds to purchase grouting equipment. With council approval, the department has just started work on a manhole remediation program using Avanti liquid acrylic sealers applied with an Avanti variable-ratio pump.

“By doing it in-house we can save money astronomically over contracting out,” says Quesenbery. “Avanti came out and trained us to handle the product, and we’ve just started tackling the problem. Once we paid for the equipment, we were sealing for about half the unit price compared to contracting.”

While the department is fully capable of dig-and-replace operations for pipe sections of up to 100 feet, crew members are now training in the use of Link-Pipe trenchless technology, which employs internally applied prefabricated stainless steel sleeves. The target proving ground is the system’s leakiest hydraulic basin.

“We have a high degree of confidence that this will work for us,” says Quesenbery. “We’ve got 20 sleeves waiting here in our storehouse. With this technology, we’ll take the city from old school right up to speed.”

The department is also tendering its first cured-in-place pipe lining contract, a section about 950 feet long. With exceptional progress in stabilizing the system, the department has established a plan to perform a complete cleaning of the system every five years and a camera inspection every 10, contingent on availability of funds.

“We needed a lot of good tools to do all of the jobs we’ve taken on in-house, and they’re all steps in the right direction,” says Lapinsky. “Thanks to the response of the mayor, city council and Aberdeen citizens, we’ve made giant leaps, and we’re a lot further ahead than a lot of communities in regaining all of the capacity we once had.”


Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.