State Street Scribe
by Jeff Wing
Santa Barbara, celebrated the world over as a vacation paradise, planted by the Gods of Commerce ‘twixt mountain and sea, is awash in crap. What can one say? Every day, Life breathes, eats, procreates and eliminates waste product—and roughly in that order. In a tourist-dependent Shangri-La like Santa Barbara, all that denuded filet mignon and blue-ribbon wine has to get out of sight and out of mind as quickly and efficiently as possible, and anymore it’s considered déclassé to simply dump it into the ocean.
Thus, Santa Barbara’s El Estero Wastewater Treatment Plant, which, despite its name, is not an estuary. Graceful long-necked birds do not dip their heads in cooling, fragrant waters here. But this loose collection of oddly shaped buildings, sandwiched between the Santa Barbara Rescue Mission and Chase Palm Park, is the unseen and unsung custodian of our town’s eight million daily gallons of sewage—and the last bulwark between a downhill-racing tsunami of crap and the bright blue Pacific that would otherwise be its terminus.
The lowest-lying point in Santa Barbara is said to be El Estero’s Influent Pump Station, the 60-foot-deep mechanized bore hole that is the nexus of Santa Barbara’s sewer system, the drain into which the rank effluvium of 90,000 souls pours nonstop day and night, in a frothing torrent you have to see to believe.
The rest of the compound, a collection of seemingly unrelated buildings, is a clanking, whirring, Dr. Seuss pastiche of gravity separators, sludge thickeners, grit removers, bubbly merde suspenders, slime squeezers, heat exchangers and microbial poo eaters.
Willy Wonka this ain’t.
I arrive at El Estero Wastewater on a recent weekend afternoon with a head full of questions; how does it all tie together? How are the liquids and solids separated? How much of the liquid is cycled back out to refresh our roses? Does the place ever break down? What role does microbial life play in the process? Is there a chance that I might be splashed with crap?
“Hey. I’m Adam.”
Senior Plant Operator Adam Munce is a spirited, funny, lightly bearded and encyclopedically informed thirtysomething. He is also a Grade Five Wastewater Plant Operator, the highest classification. This means, apart from giving him the mojo to jump in with authority on those rare occasions the party chatter turns to wastewater, he is sufficiently versed in chemistry, mechanical engineering, water reclamation, microbiology and hydrophysics to keep the plant and its odd menagerie of systems operational. He’s a sort of a scatological Renaissance man. It is in his professional and personal interest to see to it that the stuff we Santa Barbarans expel into porcelain doesn’t pop up in the tidal shallows like a bobbing apple from hell.
But how does all that biomass get here?
We are standing outside the Influent Pump Station at the front of the compound. It is the first stop for the onrushing sewage, which enters the plant through four massive, underground trunk lines, narrows to two and streams into the 60-foot hole we’re about to descend.
“You flush your toilet, it goes into the sewer line. It’s flowing by gravity to the plant,” says Munce. “That’s why in this building we have the lowest point in the city. Because it’s all flowing down into the plant.”
It’s worth noting here that the two main objectives of El Estero, very generally speaking, are to clarify and concentrate. Incoming water-based stuff will be clarified and disinfected for the long tube ride out to sea and to our public parks and gardens. The frightening solid stuff will be collected and scraped and skimmed and pressed and massaged and fed to micro-gluttons whose feasting will chemically change the stuff from our base excrement into a beneficial, if unearthly, black Jello.
Following this very first introduction of sewage into the treatment regimen, the processes will separate as plainly as the fork in a road and proceed along the two aforementioned tracks, solid and liquid.
Let’s be brave and go with the solid flow
Munce and I walk down two flights of stairs into the Influent Pump Station, a lavishly machined hole. Eau de toilette wafts gently on the air. At the bottom of the stairs is a loud, spooky, well-lit concrete chamber the size of a small bedroom. The floor of metal grating is suspended over a channel of swift-moving sewage that courses along beneath us like a foul River Styx, glittering blackly and rushing just underfoot.
I stare straight down at Santa Barbara’s collective gastronomic soul pouring into this little cement room 40 feet underground. Whether these recent meals were Michelin-rated or something snagged at a drive-thru, the egalitarianism of the digestive process has made a dark foamy mush of all of it. Hollow square columns in the room rise from floor to ceiling, longitudinal bar filters at their bases. The mechanized whine of huge pumps can be heard nearby, not quite deafening. They will hoist the stuff back up to ground after this first treatment.
“This is the main line coming in; this is the main gate,” Munce yells over the din.
The metal filters screen out the larger pieces of trash: rags, jewelry, cash, tampons, the odd bewildered goldfish. The trash is screened out of the flow by the filters. When trash hits the screens, a flow differential is detected, cuing the automated elevators within the metal columns to hoist the common garbage to the surface, where it is dumped into a contraption and scrubbed.
“It’s like a giant washing machine. It’s called a washer-compactor,” says Munce.
The showered and shampooed garbage is bagged, and Marborg comes and takes it away.
Back downstairs we pass through a door and take a gander at the beautiful new pumps that look like the subterranean machinery of the Krell in the sci-fi classic filmForbidden Planet—immense, shiny metal dynamos held fast with massive bolts.
We descend one more level to the bottom of the hole, the dreaded Wet Well. Water Resources Technician Madeline Ward, with whom I’d arranged to visit the plant, had earlier warned me that “we generally don’t take people down into the Wet Well unless they’re brave college kids… it is the rawest part of the plant, and even I try to avoid that place.”
Lead on, Mr. Munce.
Another flight down, more see-through metal flooring and another loud concrete room, this one deeper and that much closer to the bowels of the earth. This time, the maddened sewage is in plain sight, an amazing unshielded stinky bubbling primordial pool of gunk, a city’s intestinal secrets all gathered in one horrific, roiling pit. Majestic, in its way.
The trash-free sewage next gets pumped up to the Grit Chamber. The water is slowed way down and filled with fizzy bubbles that scrub the poop off the grit and sand that also flows through our sewers with every flush. The Grit Chamber then puts the smelly stuff in suspension while the rocky stuff falls. After that, it goes to a goofy-looking machine called the Hydro-Gritter, which, it must be said, looks a little worse for the wear, a bit like a rusting high-school science project. A cyclonic water effect inside the Hydro-Gritter centrifugally separates the fine dirt and sand from the water, and then a slowpoke augur inside the lower housing turns like a screw and lifts the separated sand and other non-poop gunk out of the tank and deposits it down a separate chute.
There is only one Hydro-Gritter and that’s an anomaly here. In the non-stop world of sewage treatment, redundancy is all. Should a major link in the chain fail at El Estero, its mechanical twin steps in and takes up the task without blinking. The whole of the plant features this sort of doubling up. One thing you don’t want is sewage running amok because something breaks and you have to turn off the city’s wastewater processing plant to make a repair. Ongoing repairs and improvements to a system whose technologies are ever-changing and updating must take place in a never-ending round-robin fashion. This plant can’t be shut down. Ever. It’s a challenge.
Little Green Vikings
Now that the crap-filled water has been picked free of trash and clarified of most of the sand, it’s time to feed it to the Beasties.
We climb some steps and stand on a concrete-and-metal acre or so of water-filled troughs. Some of the troughs are placid and smooth as glass, some bubbling and covered with a disgusting gray foam that looks like the head on a pint of Guinness, if Guinness were feces-based. This is where last night’s quarter-pounder with cheese orgy begins its reincarnation as a friend of the Earth.
“Primary process is where we began to separate out the organic solids,” Munce explains. “All we were doing was slowing down the velocity of the water so that stuff would sink or float. We keep it in these retention tanks for about an hour.”
Munce gestures at a foamy trough, open to the sky. The trough is full of living things—marauding and rude and single-minded living things, bless them.
Here, the inert sludge we have been at such pains to clean and collect is about to be introduced to some starving bugs and a kind of magic is about to happen.
That is, huge tanks full of microbes are awaiting their orders.
“The water flows out of the primaries and into the reactor. This is an aerobic process,” Munce explains.
Meaning, the microbes in the reactor breathe oxygen and the more oxygenated they are, the more feverishly they go to work on the slime banquet that is their bread and butter. But, it’s not easy getting all that oxygen into the bug environment down there.
“The pumping of the air is very inefficient,” Munce notes in a disappointed tone. “Since air is only 20 percent oxygen, you have to pump a ton of air to get that water oxygenated enough to keep the bugs happy. Some plants use pure oxygen to make the process more efficient. But pure oxygen is explosive. It’s a balance.”
The bugs, giddy at the amount of oxygen and food in the water, go mad eating the stuff in there.
“When the stuff settles, the scrapers scrape it away to automated hoppers that collect it, and those solids get sent on to a refining process and then on to the Digesters,” Munce says casually.
At this point, we are looking at an Activated Sludge Process. In this exotic setting, Activated Sludge is not an oxymoron—“activated” means living. And while the idea of living sludge might conjure up 1950s B-grade horror flicks, the fact is, we are already surrounded by activated sludge in our lakes, streams, oceans and Titleist-clogged water hazards.
Out there, pillaging, Viking-like microbes eat away at nature’s sludgy refuse, doing their best to filter, ingest and change stuff for the benefit of the environment. Activating the sludge here at El Estero, under these controlled conditions, is simply mimicking in vastly accelerated fashion what Mother Nature does when given half a chance.
“There’s tons of different kinds of bugs for the activated sludge process,“ Munce says as we stare at the bubbling scum. “Depending on how much air you give them and how long you allow them to be in the system, it gives you different kinds of bugs for different kinds of treatment. We have anoxic selectors that allow you to control the ratio of air to food and so select what kinds of bacteria are present; it’s super complicated. This is a giant science experiment. The bugs are trying to live with each other, but they’re also fighting each other for food. You just want to keep the right bugs happy so they’ll do what you want them to do.”
Next, the sated bugs are sent to another trough, a quiet one absent the over-exciting bubble action. Their big ol’ bellies drag them en masse to the bottom, and they are allowed to rest and digest. This bottom-covering matrix of slime and sated bugs is Activated Sludge.
“Soon, they’re starting to get hungry again,“ Munce says enthusiastically. “So we pump them back through the system—the Return Activated Sludge Process—they have fresh food, they have oxygen. It’s time to eat again, boys!”
As the process continues, a certain amount of bacteria has to be drawn off and removed as Waste Activated Sludge or it will replicate until the entire plant clogs up with frisky and polygamous bacteria.
“They’re sent off to die,” as Munce puts it with nary a hint of emotion.
I stare across the various troughs, thinking of the generations of bacteria living and dying and dating and consummating; a Sidney Sheldon novel, but with very small characters. Life. What an inexplicable wonder. On the other hand, in one of the tanks, some ducks and a filthy-looking gull are paddling around in the smelly poop-infused water.
Reclaiming a City’s Slop
The main struggle with the sludge, believe it or not, is to thicken it, to get as much water out of it as possible. One of the last stops before the sludge goes to the patiently waiting Anaerobic Digesters is the Dissolved Air Flotation (DAF). Here, micro bubbles are introduced to the sludge. The sludge sticks to the bubbles and is extracted, leaving more water behind. This thickened sludge now has its final dance with the microbes as it is fed to the Anaerobic Digesters. These bacteria are not oxygen-breathing (hence the prefix “an” before “aerobic”).
When our poop is finally introduced to the Anaerobic Digesters’ chambers, we can imagine it as a sort of joyous reunion of our scat with the bugs that most adore it—these bugs are the same as those that roam so usefully through our tightly wound intestines. The monstrous vats that hold the Digesters must be kept at a constant 98.6 degrees Fahrenheit. They think they are in an intestinal tract, and it is not in our interest to disabuse them of that idea.
The Anaerobic Digesters in their airless chamber work at the sludge for 30 days, by which time they have, through the awe and mystery of chemistry, turned the awful stuff you couldn’t bear to contemplate as it swirled down the john into an odorless, nutrient-rich digestate that has many uses, not the least of which is a super-food for plants (though not the edible kind, in case you’re eating broccoli as you read this).
Finally, the thoroughly worked-over solids are pushed to still more tanks, where a polymer, a sort of long, stringy macromolecule, is added to thicken the fertilizer-grade sludge further through a coagulation and draining process called Dewatering. This thick stuff, which “looks like black cottage cheese” according to my host, is then squeezed through rollers and still more stubbornly clinging water is pushed through a permeable belt. The remaining semi-solid is stored on site in what is called the Sludge Bay and later hauled off in trucks for composting.
“This is the poop of the City of Santa Barbara turned into something really useful!” I gush.
“Yep,” Munce says. “This is what I like. It’s weird stuff. It looks like dirt, but it wiggles. It’s only about 15-percent solid.”
He courageously nudges the huge pile of it with his work boot, and the whole mass wobbles like two tons of Jello. “Lots of times, seeds that come through the whole process remain viable,” Munce says, “and you get these amazing tomato plants, pepper plants, just shooting up out of this stuff.”
Aside from doing Santa Barbara’s dirty work, El Estero is also a Reclaimed Water Exhibit, a demonstration garden to show the public that plants do just fine and even thrive with reclaimed water. The landscaping at El Estero is gorgeous and robust. Munce says sometimes a bit of this proto-mulch will spill along the side of the driveway into the dirt when trucks are being loaded and a huge plant will just sprout there overnight.
I notice the stuff doesn’t smell.
“All the stink has been digested out of it,” Munce says. “And you can pump this stuff, like concrete. It’s a weird material.”
I lean in a last time to stare.
“Go ahead, you can grab a handful,” says Munce. “It won’t hurt you.”