Bringing It All Together

Ohio’s Northwestern Water and Sewer District builds its reputation on solving tough system problems

Bringing It All Together

David Cromley, sanitary engineering aid III at Northwestern Water & Sewer District, in the control room of the sanitary sewer equalization basin that he helped to complete in 2017. The basin holds 2.2 million gallons.

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Ohio’s Northwestern Water & Sewer District was established in 1994 to unite the utilities of five municipalities and 14 townships in Wood County, Ohio. The district has grown since then to include 13 municipalities and 20 townships — in large part due to its reputation as a problem-solver, helping newly incorporated members solve problems such as inflow and infiltration and working to normalize costs across the service area.

The district serves just under 20,000 accounts with sewer and water service primarily in Wood County, just south of Toledo.

“The five municipalities that first joined did not have their own sewer or water services,” says Tom Stalter, district engineer. “They joined on hopes that we would supply those services. Other municipalities didn’t find it cost-effective to operate their systems, so they asked us to take ownership of their systems and bring them up to speed. Like so many small systems across the country, many of these systems are aging, in poor condition, or have state EPA findings and orders against them. In some cases, the EPA will hold off from issuing an order if we’re on the case. They see us as an organization that can solve problems.”

Today, the district’s service map extends to parts of all the county’s 19 townships, excluding centers such as Bowling Green and Perrysburg, which operate independent systems. In Northwood, Tontogany, Portage, Walbridge, and several other communities, the district owns the utility systems, although the communities are not officially district members. The town of Luckey owns its system but contracts operation to the district. The member town of McComb lies in Hancock County to the south, while the district’s responsibilities for the town of Risingsun straddle the border to a municipal area located in Sandusky County.

Diverse system

The sewer system comprises 355 miles of sewer pipe over more than 581 square miles. Managing the diverse utility systems and ensuring they meet specifications is a delicate balancing act.

“We have to make good business decisions while serving the public,” Stalter says. “The beauty of being a sewer and water district is that we don’t have to worry about decisions made at election time. We charge people what it costs to run the system.”

In some cases, new district members are already experiencing system problems such as I&I that require significant capital infusions to remedy.

“We can’t always equalize rates immediately,” Stalter says. “We have to decide how much of the cost of improving the system will have to be borne by the customers served by those utilities. Often, we can reduce costs through grant funding by the Ohio EPA and the U.S. Department of Agriculture. They’re very supportive of what we do when we take on the operation of these challenged systems.”

A case in point is the village of McComb, a community of 1,700 where the cost of expensive wastewater and water treatment plant upgrades was too high for the town to take on by itself.

“We received enough grant and loan money to reduce their costs by about half,” Stalter says. “McComb residents paid 23 percent of the project costs while the entire system picked up 20 percent. When we take over a system, we try to make sure that the residents pay their fair share, but we also want to make sure the cost of that share is as low as possible. Our goal is that, down the road, they’ll be paying similar rates to every customer in the system.”

The district sewer system includes a series of 12 wastewater plants. Some wastewater treatment services are contracted from the adjacent cities of Toledo, Bowling Green, Oregon and Fostoria. Wastewater is conveyed by more than 70 pump stations. The condition of the pipe network runs from “poor” to “great” with overall condition gradually improving. Pipe diameters range from 2 inches for grinder systems up to 60 inches, and materials range from clay, concrete, and steel to PVC.

Cost-efficient compliance

“For some of the small communities that were under orders, we built new sewer systems, sewer extensions, oxidation ditches, and lagoons,” Stalter says. “We do whatever is required to bring them into compliance in the most cost-effective way.”

In-house crews handle routine repairs, while contractors handle larger jobs and capital improvement projects. The capital budget has averaged $25 million dollars per year over the last several years.

A coordinated campaign against I&I was accelerated in 2012 when the district was negotiating new contracts with Toledo to provide wastewater services.

“Toledo was under orders from the U.S. EPA and we were required, as part of the terms of our contract renewal, to demonstrate that we were making efforts to limit wet-weather flow,” Stalter says. “At that point, we really ramped up our efforts against the I&I problem.”

The district used consultants and in-house staff to conduct a blitz of camera inspections, smoke testing and flowmeter analysis to identify the areas with the worst problems. Initial testing focused on the older, urbanized northern end of the system.

Unique solutions

“We discovered wide-ranging problems and addressed the worst with remediation and new construction,” Stalter says. “We responded with unique solutions for each community. For example, we used pipe bursting in the town of Walbridge, where shallow sewer lines ran beneath buildings on forgotten easements, followed by manhole rehabilitation.”

The district has also relied more on sewer grouting, which was used extensively in the village of Millbury to restore clay and concrete pipe integrity.

The study also discovered that leaking laterals on private property were a significant overall contributor to I&I. In the city of Northwood, the district implemented a remediation program for sewer laterals, helping to finance lateral remediation beyond the property line onto private property.

“We met with some success on that,” Stalter says. “We’re now in the process of rolling out a broader program.”

The district has also embarked on an intensive campaign to televise every foot of the system — including all sewer laterals — over 10 to 15 years. The district purchased an inspection truck outfitted with a CUES camera and LAMP II Lateral Launcher in early 2017.

“We have a dedicated crew of two working on that project every day,” Stalter says. “They’re supervised by a third crew member who collects, organizes and analyzes data.”

The district owns two Vactor 2100 combo trucks. One serves multiple needs, including assisting construction crews. The other divides its time between scheduled cleaning and clearing the way for the camera crew.

I&I solution

The district’s biggest I&I project to date has been the construction of a 2-million-gallon flow equalization tank. The construction cost of $5.4 million was funded through a Water Pollution Control Loan Fund through the Ohio EPA. Serving Northwood, Millbury, and parts of Lake Township, the concrete tank was completed in July 2017 and now ties into a trunk main conveying wastewater for processing in the city of Oregon’s regional wastewater treatment plant.

“Oregon was on a compliance schedule that required it to upgrade its plant but also required satellite systems to reduce wet-weather flow,” Stalter says. “As part of our wastewater contract negotiations with Oregon, we agreed to build the equalization tank to store our excess wet-weather flow. When the sewer starts to surcharge, the excess pumps into the tank. Once the storm is over, the tank begins to bleed the surcharge back into the system.”

The wastewater contract allows the district to convey 5 million gallons to Oregon’s wastewater treatment plant each day. A hydraulically controlled flow-level regulator automatically “pinches” itself down as flows approach the maximum cutoff.

The district is currently earmarking $1.5 to $2 million per year in capital improvements, targeting dollars for maximum effect on reducing overall I&I. However, Stalter notes that the battle is a long-term engagement that doesn’t always deliver immediate results.

“We know we’ve improved the system when we’ve remediated a pipe or completed new construction,” Stalter says. “But stormwater has a way of finding the next-best entry point into the system. However, we know we’re doing the right things and expect to see solid data on peak flows over five to 10 years down the road. We happen to be good at what we’re doing, and we have the right staff to fix the problem.”



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