Ready for the Next Storm

Coastal community protects sensitive environment thanks to a new approach to system monitoring.

Ready for the Next Storm

Apalachicola City Manager Travis Wade works closely with William Cox, the city’s lead wastewater plant operator, to monitor the efficiency and effectiveness of the sanitary sewer system. (Photography by David Adlerstein)

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One of the oldest port cities in the state of Florida (est. 1831), Apalachicola is known as the oyster capital of the world. The health of that and other fisheries depends greatly on the quality of water flowing from the Apalachicola River into Apalachicola Bay.

Located on the Gulf of Mexico, about halfway across the panhandle region, Apalachicola also depends on its tourist trade, another industry that relies on clean water for an attractive recreational environment. Standing watch over the quality of that water are the staff of the city of Apalachicola Collections Department. They handle water and wastewater issues, while the Public Works cover stormwater concerns.

Travis Wade, Apalachicola’s city manager, works closely with William Cox, the city’s lead wastewater plant operator, to monitor the efficiency and effectiveness of the sanitary sewer system. Their most vexing problem today is getting a handle on inflow and infiltration issues that threaten water quality.

Growing danger

Like many established cities in the eastern U.S., Apalachicola’s wastewater collections system, and its wastewater treatment plant, are approaching the end of their initial design life. Tree roots seeking water worked their way into cracks and through pipe joints, where settling and subtle ground movement caused seams to separate.

Eventually, stormwater also found its way into the pipes through these pathways, creating a widespread problem with infiltration. Though most of the system’s main and lateral lines have largely been replaced by modern PVC pipes, there are still places where the water seeps in, and sometimes in a significant way.

Another source, Cox explains, was “road construction and other types of utilities coming through and damaging existing lines. It just creates so much infiltration that the utility couldn’t handle that much flow coming in anymore.”

When they become aware of them, city crews have been digging up these types of damaged pipes and repairing them with a concrete-and-fabric patch over the top to prevent them serving as infiltration ingresses. “That’s something we’ll be seeking grant money for, because I would love to replace all of our terra cotta pipes with PVC or a harder, better substitute. Flooding caused by ineffective stormwater drains results in infiltration into the sewer system.” Wade says.

With its location right on the Gulf, Apalachicola’s sanitary system is also susceptible to massive inflow during tropical storms and hurricanes. Between drenching tropical downpours, high tides and significant storm surge, the system can be easily overwhelmed with both fresh and saltwater inundation.

Trial by flood

One particular storm, Hurricane Sally, brought the system’s weaknesses into high relief as it came ashore in nearby Alabama as a Category 2 storm on Sunday, Aug. 30, 2020.

“The guys on the field crew worked 24 hours a day,” Wade recalls. “I actually went out with them one night and worked until 1 or 2 o’clock in the morning, just helping to find leaks in the system or areas where (infrastructure was) overwhelmed. We sent out our 800-gallon pump wagon — now we have two (we bought an extra one because of that event) — but we also had two local vendors in the area who brought their pumper trucks out and helped. We called in the city of Tallahassee, which sent three very large pump trucks, and it took all of that for us to get on top of the situation. It took days, and that exhausted everybody with the city. We were all almost dead.”

That Sunday, 7.85 inches of rain fell, triple the previous record for that date. Another 2 inches fell the next morning, making the total two-day deluge just under 10 inches. Apalachicola’s wastewater treatment plant is rated for 1 mgd, with an average flow of 300,000 gpd. Then-mayor Kevin Begos reported the following Wednesday to The Apalachicola Times newspaper that the math suggested, “roughly 347,571,200 gallons of rain fell on the city in a little over a single day, not including more in greater Apalachicola.”

The sheer volume of water completely overwhelmed the entire sanitary system. Begos allowed that neighboring Eastpoint’s collections system “crashed too, but ours was worse.”

Hybrid system

The incident led collections field crew supervisor Rhett Butler to seek out advice from Michael Pringle, director of operations for Flovac Vacuum Sewer Systems, an engineering firm and manufacturer of vacuum sewerage systems.

Flovac engineers understood that Apalachicola’s location at the shore makes it environmentally sensitive as well as an engineering challenge because of its high water table. Those are the reasons the city had previously purchased an Airvac Inc. vacuum sewerage system and installed it to extend the existing gravity system, but they were still experiencing surcharges and SSOs on their now hybrid system.

“The city elected to go with another type of sewer system,” Cox says. “The depth that our lines were at, it was going to cost all kinds of money to do trench boxes. Then having to well point the system to get everything pumped low enough to where they could safely work in that area. … It just made more sense — and was a lot cheaper — to go with a vacuum system where you wouldn’t have to dig as deep.”

To keep a handle on costs, they decided to continue using the gravity system for the higher-elevation north side of Apalachicola as well as construct the new vacuum system primarily south of Martin Luther King boulevard, a main east-west artery through the city.

“The vacuum system predominantly serves the outlying areas of town and the river,” Cox says. “Going to the west, it’s got the majority of the community.” This was enabled by the ability of the vacuum system to accommodate the higher water table at the lower elevations toward the Gulf shoreline.

Timely data

Pringle believed adding the Flovac monitoring system to the vacuum segment would extend functionality and be part of the solution to the city’s massive I&I woes. He met with the mayor and his team and introduced them to the system. The FMS places sensors in each of the vacuum collection pits, tracking changes in vacuum pressure, which indicates flow volume. Higher pressure means more volume, and if that number rises, something unusual is going on regarding sudden influx of water from somewhere. The sensors transmit alerts when flows go outside established parameters, which are picked up by Flovac’s digital smartphone app and transmitted wirelessly to users.

City engineers worked with Flovac to determine how the FMS could be successfully deployed in Apalachicola and were able to deploy the system within a couple weeks. The unique functionality of the FMS, Pringle says, is due to in-house design coupled with the ability to make performance changes remotely.

Because the city has not implemented any kind of GIS digital asset management, managers and field crews were both impressed with the fact that the FMS app serves some of the same purposes for the vacuum side of their collections system. This has proven a boon to both preventive maintenance and emergency response.

“Because of the Flovac monitors, we’re able to know where we have a problem, sometimes even before we get an alarm from our vacuum station auto-dialer,” Cox says. “This monitoring system will actually text us and let us know which station is messed up, and it will tell us before we even get the alarm from the system.”

One of the advantages of the FMS is that it is customizable to each system’s needs, and Butler and his field crew members, John Marshall and Johnny Harris, fine-tuned the system by adjusting the vacuum pressure on those pits and the monitors. “This allowed us to make it an even better system for our town,” Wade says.

Getting better

As much as the new technology has helped, it hasn’t solved all of Apalachicola’s I&I woes. There are still problems with aging infrastructure.

“We do still have infiltration on both the gravity and the vacuum systems,” Cox says. “I can’t really say from a plant operator’s standpoint that we’ve seen a dramatic reduction in I&I at this point because for everything that gets fixed in one area, it seems like there’s something new showing up in another.

“But these monitors have actually allowed us to determine — like, we know for a fact — when we need to pay attention to something. We’ve got one pit right now that every time the tide comes in, it starts operating inconsistently. So we know (from the monitor data) that we have something going on with that one. Now it’s just a matter of getting out there and making the repair. But there again, we don’t have monitors on every single connection that’s out there.

About a year and a half ago, the crews lined 25 of the most deteriorated manholes in the gravity system. They also maintain four lift stations with two pumps each, which are being ravaged by H2S. But right now, Cox says they’re just trying to identify I&I locations. “That’s the first challenge. We’re trying to get the funding to do that. That’s going to have to be something that comes from the legislature, because with our city, we’re not able to afford that.”

Stepping up

They’ve been consistently seeking such funds, writing grant applications for infrastructure studies.

“We have a pressing need for a stormwater study, too,” Wade says. “We have I&I in our stormwater system ... roads collapsing, because the dirt above is being pulled down through the storm drains and leaving the road hovering over the base. We have that in a lot of places and it’s dangerous. Then if it’s asphalt, it just falls through when we have a hole there. We have some concrete … one day you realize you’re looking down on a crack and it’s 14, 18 inches deep under the concrete road, and you pray to God a garbage truck doesn’t run through there and fall in. We have a street that’s closed down right now because of that.”

Still, the Collections Department feels a sense of accomplishment from getting a handle on the most extreme and destructive facets of their continuing I&I issues. Cox is proud that they all stepped up to the plate when they realized how bad the situation was and made use of all available resources to fix it.

Like Butler reaching out to Pringle, Cox says it’s important to recognize your own limitations and get past them by leveraging other people’s knowledge. “Don’t be afraid to ask questions from other people who have experience and expertise, and whatever their advice is, don’t take that for granted.”


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