Al Andrade talks about the settling tank he is standing near at the Fields Point treatment plant, in Providence. Debris from the water settles out before it is pumped to another area, where sludge is removed.

>

The Providence Journal Bob Breidenbach

PROVIDENCE — We shall dispense with the normal curiosity first.

Yes, Providence’s Fields Point sewage treatment plant, Rhode Island’s largest, smells.

“It can be very putrid, it can be very bad,” says Al Andrade, a longtime mechanic with the Narragansett Bay Commission, owner of the plant. “If you’re not used to it, you will get sick.”

But that is only when the plant is having a bad day, so to speak.

“In general,” Andrade says, “if it keeps rolling and it keeps moving and we’ve got it under control, there’s really not much of a smell at all.”

And that not-much-of-a-smell, says Jamie Samons, the commission’s public affairs manager, is more akin to a household odor than, well, you know.

“I always find that the smell is more like a musty basement smell as opposed to a public restroom smell,” Samons says.

OK, curiosity satisfied. Now join Andrade and Samons as they tour the country’s third oldest wastewater treatment plant, and one of its cleanest. The plant opened in 1901 (and has been repeatedly updated). Only facilities in Philadelphia and Brooklyn are older.

Samons begins with a talk she’s given many times inside the air-conditioned, unscented building that houses the plant’s control center, where input, output, water purity, bacteria count and many other factors are monitored and controlled. She stands at a wall-mounted chart that details the journey that sewage, an average of about 45 million gallons on a dry day, takes. On rainy days, it can handle 200 million gallons, approximately the volume of 303 Olympic-sized swimming pools. That’s a lot of … wastewater.

It comes from Providence, Johnston, North Providence, and parts of Lincoln and Cranston, through 61 miles of underground pipes. Arriving at the plant, it encounters enclosed bar racks that screen out anything larger than about an inch-and-a-half. Given that most sewage is born in a toilet, a tub or a sink, you would think there’s not much to catch. But manhole covers can be lifted, big things shoved clandestinely inside. Things including mattresses, bicycles, Venetian blinds and dead animals.

“We have no bodies yet,” Samons says. “No huge sacks of money or anything very glamorous like that. Just crazy stuff. Like, who throws Venetian blinds down a sewer? I mean, that takes effort, you know? You have to pop that 100-pound manhole cover to shove a mattress down there. Who does that? I guess it’s just the challenge.”

What clears the bars moves along to the grit building, where sand, silt, asphalt and “abrasives” –– egg shells, for example –– are removed. Like what the bar screens catch, this is trucked to the Central Landfill in Johnston.

From the grit building, the sewage –– cleaner, but hardly clean –– is pumped to primary treatment tanks, which are open to the air and hold up to a million gallons. Then, pumps move the sewage to gravity thickener tanks, located inside igloo-shaped metal buildings that are unbearably hot and stinky inside. Imprisonment here would be an appropriate sentence for particularly heinous criminals.

Andrade crosses a catwalk to the center of one of the tanks. What settles to the bottom here entered the world in toilets.

“This is the real sludge,” Andrade says. “This is the real compact doo-doo. This is it.”

In times past, the sludge was incinerated here at Fields Point. It seems unconscionable now. But today, it is sent to a plant in Maine, where Houston-based Synagro Technologies, which bills itself as “the largest recycler of organic residuals in the United States,” combines it with yard waste and leaves, turning it into a soil additive approved for use in Florida orange groves and Midwest wheat fields.

Doo-doo in, soil out. Think of that over your morning OJ.

Outside again, where the nostrils detect but a trace of odor, Andrade walks with Samons to the aeration tanks, the wastewater’s next destination on its way to where the fish live and the summertime people swim. Like the primary tanks, they are exposed to sunlight and open air –– but what happens here is a sort of biological alchemy. A strange brew of microbes live in these tanks. Wastewater folks call them “the bugs,” a title they use reverentially.

Says Samons: “It’s fair to say that the most important thing that we do here is keep these bugs happy. We do that by giving them air and by giving them food –– and the food is the organic matter of the sewage.”

Which translates into:

“They eat poo. And when they eat poo, they get fat and happy and heavy and they become heavy enough to settle out in the final treatment, in the final clarifiers.”

Samons later elaborates on the more specific identities of the bugs, describing them as “microscopic organisms ranging from one-celled bacteria, to protozoa like amoeba, flagellates, ciliates –– free-swimming and stalked –– to higher life-form organisms called rotifers.

“Most organism names reflect how they move in water or how they gather food. Amoeba are pseudo pods –– false-foot –– and they move like The Blob. Flagellates use their ‘whip-like’ tail to move. Ciliates use ‘hair-like’ structures to move.” Many of these creatures live inside the human intestine, another efficient processor of waste. As Samons notes, they are equally pleased with the accommodations at Fields Point.

Workers, however, must be particularly careful when near these tanks.

“This aeration process is the most exciting part of the treatment process,” Samons says, “but it’s also the most dangerous because the water here is so highly oxygenated that human beings are not buoyant. If someone were to fall into one of these tanks, they would be sucked down onto the bottom.”

Someone was, in December 1993. Bay Commission employee John J. Lennon drowned. The plant displays a plaque memorializing him.

Andrade and Samons walk to the far side of the aeration tanks. The tour is almost over. After treatment with sodium hypochloride –– essentially bleach –– and then a second chemical to neutralize any residual bleach, it’s good to go.

“What comes out of aeration on top,” Andrade says, “goes to the final tanks. That’s the last stage before it goes to the effluent channel to head out to the bay, which is when it’s fully treated. That’s the end of the process.”

At the end of his day, Andrade drives the five minutes to his home.

“The first thing I do is go shower. I definitely go shower, brush my teeth, gargle and all that. ‘Cause you know. After a day here, it settles with you. It’s on you. And if it’s a real good day I’ll have an ice cold beer.”

Information about the Fields Point plant and the Narragansett Bay Commission can be found at: www.narrabay.com/index.asp

gwmiller@projo.com