CHESTERTOWN — Following John Hanson Road when leaving Chestertown, some very important conservation work is being done. Across the lagoon, now used for storage of treated wastewater, more specifically effluent, and bird watching, tons of clean water is being dumped back into the rivers.
Water, when tested, is cleaner than the Chester River it’s being dumped into.
Water that was wastewater at one time, streaming from the 14 pump stations in Chestertown.
Bob Sipes, utilities manager in Chestertown said, “People seem interested in learning but then they hear it’s wastewater; they shy away from it.”
He doesn’t.
The town is grateful for that too.
If something breaks down, he’s on call. And once every month he presents before the Chestertown Council, and much of the time it’s about keeping this ever important treatment plant running.
He provided a tour to Kent County News showing the cycle after they receive wastewater from the stations; the process, the problems they sometimes face and the purpose of this 24-hour operation.
Chestertown’s wastewater system is an activated sludge plant. It uses a biological process used to oxidize carbonaceous biological matter, oxidizing nitrogenous matter (mainly ammonium and nitrogen) in biological matter, and removing nutrients like nitrogen and phosphorus.
They do this using microorganisms... bacteria specifically.
Bugs in even simpler terms.
A simple explanation is the plant uses these “bugs” found in sludge (biomass) to eat away at the filth to leave clean water behind.
“All the bacteria that’s necessary for wastewater treatment already exists in the wastewater itself,” he said.
At the start of the treatment process, wastewater and sludge are separate.
Wastewater flows first from the pump stations into the plant though a screen that takes out everything bigger than a pea. The screen removes the grit (sand) and both get dumped in the trash after washed.
The biomass that’s created during the treatment process, (sludge) contains 40% bacteria (bugs) and is mixed in the same line as the wastewater.
Sludge and wastewater merge.
From there it’s a game of orchestrating where everything goes, adding oxygen, controlling the flow and adjusting when necessary.
“So all we do is create the environment where the bacteria we want thrive, and the ones we don’t want, die off,” Sipes said.
Sludge and wastewater travel down into a splitter box and from there goes into separate channels, six of them on each side and a reserve they keep off to keep it mixed, what they call “mixed liquor.” Three channels are aerated (oxygen) and three are not, because they need both aerobic bacteria and anaerobic bacteria in the treatment process.
In the aerated channels, Sipes explained they organically remove the nitrogen by turning ammonia into nitrates and nitrites. They also need air for aerobic bacteria to thrive.
The channels with no oxygen allows anaerobic bacteria to live. Anaerobic bacteria are important, Sipes noted, because they can strip oxygen molecules from the nitrates and nitrites, leaving only nitrogen gas.
They are also doing BOD (biochemical oxygen demand) and suspended solids removal as well. Sipes pointed out the bacteria creates a zoogleal mass, that acts like a glue and sticks things together.
After BOD, which makes the water a brown color, is removed, it goes into another splitter box, designed to divide up the flow evenly, called clarifiers.
At the center of the clarifiers indicated by a brown cloud, the solids begin to separate from the water, sinking to the bottom in the form of little balls called pinflocs.
“This isn’t the final part of the treatment process. Here, we separate the mixed liquor from the water, and when we do that, that means the treatment process is about done.”
But not quite yet, Sipes added.
Those same solids go back to the start of the operation where it begins the treatment process over again.
“It’s a continuous loop,” Sipes pointed out.
The BOD and lots of organisms get eaten up.
At this point BOD is removed as well as suspended solids and phosphorous and nitrogen. Aluminum fluoride binds the phosphate with the flocs, and is eventually wasted out of the system.
The water remaining looks clean, but not quite yet.
To make it safe the water’s blasted by UV light courtesy of 128 bulbs in crystal sleeves. These disinfect the water, sterilizing any pathogenic bacteria remaining.
Now it’s ready to pour into the river.
The entire plant is run by computer systems with calibrations familiar from Sipe’s experience as an electrician.
To make their lives way easier, the UV 3,000 PLS, keeps his crew from having to bring the results to the lab, providing readouts every ten minutes.
It allows for adjustment as well, much like how the entire plant is designed.
And when it’s finished, flowing through that channel is clean water, not a trace of filth. It’s a brilliant way of conserving that might be missed by some nature advocates.
As Sipes reiterated, it’s cleaner water than the river itself. Cleaner than the water found in people’s well water too.
Sipes, who’s been working this industry for 30 years, gets a sense of satisfaction at, not just the results of the clean water, but how the plant operates.
He said it’s far more superior than other methods of wastewater treatment.
He explained how Chestertown does it is a 100 year-old process, discovered accidentally in London. They wanted a design to dump their waste into the Thames, but the architect wanted to control the flow of it and so created walls. That created buildup which made sludge. They noticed after a period of time it didn’t smell like raw sewage at all.
Within that sludge were the bacteria, eating away at it.
It’s an interesting process, and for those who are looking for lucrative careers, Sipes is always seeking operators. He acknowledged it’s “a dirty job,” obviously.
Hosing down screens and fixing busted lines to name just a few. Sometimes mechanical failure mingles with the wastewater flow creating a huge mess.
But for the right person, it can be a good fit, starting pay at about $18 an hour.
Sipes said he doubled that after he became certified, reflecting on his career.
It’s not for everybody, he pointed out.
“If you’re just in it for the money you won’t last long. It takes a special kind of person.”
And the grime is temporary.
“It’s nothing that doesn’t wash off at the end of the day.”
Sipes encouraged anyone wanting a tour of the facility to reach out to him. He’ll explain the science of the plant, and typical of someone operating on a timed pattern, will be finished in one hour.
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