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So You Think Your Job Stinks?
Oh, Sh*t! My First Visit to a Wastewater Treatment Plant
Like most people, you probably just flush and forget it. Whether it’s the toilet you’ve just befouled or the drainage from the dishwasher, once the contents of the pipes leave your domicile, they’re quickly forgotten. But the next time you’re gazing contemplating a babbling brook, listening to your washer do a rinse cycle, or chugging a big glass of water, I want you to think of a few things. And please don’t shoot the messenger.
In the fall of 2000, I had just started my job as an editor for an engineering firm that specializes in water and wastewater treatment. My job within my group was to edit and format operation and maintenance manuals for various treatment plants. Running a treatment plant can be a complex endeavor, requiring volumes of complex written instructions for its engineers and operators; it was my responsibility to transform those convoluted directives into layman’s English and make it all look pretty.
After a few weeks of wading through several hundred pages describing the equipment and science involved with removing the nasty bits from water, my then-boss (we’ll call him “Chief”) decided I needed to actually see a plant up close and personal so that I could at least say I’d laid eyes on this crap I was reading and writing about. While curious on a professional and scientific level, I’m a borderline germophobe, and the thought of going to look at literally thousands of gallons of stuff that we flush down our toilets was making me a tad skeezed out. I was just praying that I didn’t throw up in front of my new and already beloved boss.
The Chief drove me out to a fairly large wastewater treatment plant (WWTP) on a bright and cold autumn morning. While a lot of odor control treatments were used at this particular plant (it bordering some fancypants neighborhoods and all), let’s just say it was evident that I hadn’t just stepped out of the car onto a lilac grove. It stunk. Like sh*t. Lots of sh*t.
Chief led me to a low, dome shaped structure with a door. This is one of the primary clarifiers, Chief told me. The door opened to one of the more minor circles of hell. In a nutshell, a primary clarifier is where the wastewater “relaxes” for awhile after the really big chunks are removed in the screening process (more on this shortly). This is where wastewater goes for a timeout, letting the heavier stuff (e.g., poop and chewing gum) settle on the bottom and the greasy stuff (like stuff from your garbage disposal and fabric softener) to settle on top, thus getting the water in the middle that much more ready to re-enter society. And yes, it was gross, but nothing that would give me nightmares. That was yet to come.
Chief then walked me past an anaerobic digester. We didn’t go inside; most mortals never see the inside of a digester, as the balance in there is highly delicate, and is only disturbed when absolutely necessary. Basically, a digester is where the gross solid-ish stuff from the clarifiers and some other sources goes to get heated up to about body temperature in the absence of oxygen. These conditions promote the growth of certain types of bacteria that “eat” (sorry, guys) the solid stuff, therefore leaving less solid stuff to ultimately dispose of. And as a bonus, the gases produced from the digester are usually siphoned off and used as a power source for other parts of a plant, such as boilers. Neat, huh?
But now comes the part that still makes the hair stand up on the back of my neck if I think about it. The aeration basins. An aeration basin is essentially a big, open pool of water with bubblers at the bottom that shoot up air bubbles into the water to produce yet another series of biochemical reactions that separate the solid stuff (poop and clumps of certain microorganisms) from the liquid stuff (water). Unlike most digesters, which operate in the absence of oxygen to do their job, an aeration basin needs lots of oxygen circulated through its contents to perform its intended function. Most aeration basins resemble brown, roiling, bubbling swimming pools from your nightmares. Most aeration basins are installed outdoors, as it’s generally easier and less expensive that way. However, since this WWTP was neighbors with $700K homes, it was placed inside an enormous building for aesthetic purposes. Chief opened the door to this particular house of horrors and led me in. Picture a building about half the size of a football field, but instead of a floor, there is a series of dripping metal catwalks suspended over churning and foaming brown waters about 15 feet deep that smell like a stale diaper bin. Swirling steam moves like little tornadoes around your feet. And oh – just so you know, if you ever find yourself at a wastewater plant, DO NOT fall into an aeration basin. You have about a 99.9% chance of dying due to the designed direction and currents of the water holding you down to the walls or floors of the basin. It won’t be a pleasant way to go.
The combination of the movement of the “water,” being suspended on a catwalk, and just the general heebie jeebies of where I was gave me one walloping spell of vertigo, and I grabbed onto the handrails to keep from falling down, only to hear Chief bellowing, “Don’t touch anything!” You see, if you have any cuts or abrasions or just need to scratch an itchy eye later, touching ANYTHING in and around a WWTP can cause you some problems. The people working in those plants are required to get more inoculations than someone planning to go to Africa with the Peace Corps. Every virus and bacteria know to man (and probably a few frightening mutations) are breeding like rabbits on crack in those places. Anyway, he helped me find the door through the steam and the nearest restroom to wash my hands.
While the aeration basin was frightening, the screenings area was by far the grossest. The screenings process is usually located at the very “front” of a plant, where the wastewater first comes in to be treated. The wastewater flows through these screens, where the “big chunks” are filtered through a series of bars and racks and scraped away, leaving mostly something water-like to make its way through the rest of the plant for further treatment. This is where stuff is the most real, raw, and in your face, as it were. The big chunks (“screenings”) which are scraped away from the screens are dumped into a series of gigantic trash bins. Depending on the size of the plant, local regulations, etc., the screenings are then usually trucked off to a landfill or incinerated. Imagine walking up some concrete stairs to a big cement platform, and your view looking below is about a dozen freight car-sized containers full of VERY used toilet paper, condoms, and female hygiene products. I will not throw up in front of my boss. I just had to chant this to myself, as well as remind myself that what I was seeing was nothing but a combination of nitrogen, phosphorus, ammonia, and various manufactured paper and latex products. No problem. I will not throw up in front of my boss. And we’re outta here.
The chlorine storage room made me distinctly nervous. The odds of one of those cylinders spontaneously bursting or springing a leak fast enough to kill me were astronomical, but I didn’t care for all those ominous looking displays, warning signs, meters and gauges, much less the faint ticking sound from all of the above gadgets in there.
On to the belt filter press area. A belt filter press is a kind of wide band of very resilient cloth set up on a conveyor that filters and squeezes the last little bit of measureable water from the sludge in order to make that sludge as water-free as possible. Anyway, as the solid waste in this particular process is very concentrated, the ammonia levels near these conveyors and their catch bins are enough to make you pass out. Sometimes I’m not as dumb as I look, and I had the foresight that morning to wear a turtleneck with a generous spray of perfume inside said garment. That Calvin Klein scented shirt made for a nice face mask over my nose and mouth, and staved off a great deal of gagging on my part.
We were getting near the end of the tour, where the water is disinfected to a point where it’s safe enough to release into the nearby river or stream (or lake or ocean). WWTPs use different methods to disinfect water, usually chlorine and/or ultraviolet (UV) radiation. Chlorine is used to kill microorganisms directly, whereas UV is a little more subtle; it more or less zaps the reproductive systems of the little goobers, making them unable to reproduce. We went into a concrete structure which had big channels running through it. Gates would be raised to let the mostly-treated water into the channels; then big banks of UV bulbs (think of a box about the size of an industrial refrigerator with fluorescent light tubes mounted inside) would be lowered into the water, hopefully frying any creatures like E. Coli or Cryptosporidium. Then the banks would lift up and the gates would raise again to release this last bit of plant water down a series of steps and into the very picturesque creek winding its way through the nearby park. This water wasn’t clean enough to drink, but was fine for the fish and crawdads.
I didn’t get a chance to see each and every process or treatment area. There are dozens of different kinds of wastewater plants, and no two use exactly the same processes. But for all intents and purposes, the job of a wastewater treatment plant is to separate the solids from the liquids as much as possible in order to dispose of the solids and release the liquids, once disinfected, back into the world.
But as I stood there in the golden autumn sunshine watching the water exiting the sh*t factory and splashing into the sparkling creek, it hit me that every river, stream, lake, and ocean in the world has some form of wastewater flowing into it every day by the millions of gallons. That we boat and swim in it. And more importantly, that treated wastewater entering a given body of water is picked up somewhere downstream by a water treatment plant, which will take that same water, shake it around, add some chemicals, and then send it to the drinking water distribution system and through your kitchen faucet. Oh, and you people in the deserts and other areas without a convenient or plentiful fresh water source from which to draw potential drinking water – you may have something in your area called a water reuse or water reclamation plant, where the stuff comes to the plant directly from the toilet, and eventually leaves the same facility to be routed to your bathtub, leaving out the middleman.
It took a long time to look at a river or the ocean the same way. But, like a lot of things, you just can’t dwell on the particulars of reality or you’ll go stark raving mad. Like how your food is prepared and packaged, or how many microscopic life forms are living on the handle of your refrigerator, or what that stain is on the subway seat. This stuff’ll kill ya if you think about it too much.
Aw, come on in – the water’s fine.