What you'd see in Washington's Tiber Creek sewer - if you dared to go They are not Navy SEALs or Army Rangers. They are not Green Berets. Call them Brown Berets. SAM stands for Sewer and Maintenance. Kevin and his crew work for D.C. Water. Their job, to use a digestive metaphor, is to keep the city regular. They descend into the dark and smelly places under Washington. Early in the summer, I went with them. Nearly 1,800 miles of sewers crisscross the subterranean reaches of our city. The most famous stretch - at least to those of us who like sewers - is the Tiber Creek sewer. For much of its length, it follows the contours of the creek that once ran from near Union Station, down what is now Constitution Avenue and into the Potomac. Starting in the late 1800s, the creek was encased in masonry, allowing it to serve a more cloacal function. Before I can see this watery landmark, I have to undergo safety training. At a D.C. Water facility near Nationals Park, I listen to Sorin Schwartz's briefing on the peculiar dangers of confined spaces. "Engulfment" apparently is something we need to worry about. And the atmosphere can be noxious or oxygen-deprived. "There shouldn't be anything flammable, but it is a sewer, so you never know what people throw down there," says Sorin, semi-reassuringly. Our entry point is through a manhole on Louisiana Avenue NW near the Taft Carillon. A large tripod has been set up over the shaft, and an air-monitoring device snakes into the depths below. It's nearly 2 a.m. when I get ready to enter the sewer with David Young, Mark Coghill, Tyrone Johnson and Sorin the safety man. (SAM 101 crew member Darryl Paine wasn't working that night. Kevin Glover and supervisor Steven Medley were up top.) To protect my civilian clothes, I don a white Tyvek jumpsuit. To protect my civilian head, eyes and hands, I don a hardhat, safety glasses and latex gloves. I climb awkwardly down the slippery metal rungs set into the wall. And then there I am, in the sewer, 25 feet under the street. The smell? Not nearly as bad as I'd feared. There's no doubt about what it is I'm smelling, but I've sniffed worse at county fair porta potties. Our flashlights illuminate the well-laid bricks that line the tunnel. The walls curve up to the ceiling, which is about 12 feet from the floor. The sewer is about 10 feet wide at this point, with a three-foot-wide raised brick berm along the sides of a shallow central channel. "If the water comes up over the berm, that's the signal you want to get out," says Tyrone. Noted. The liquid in the berm does look like water, actually. That is to say, it is not overly fecal, though occasionally I can see toilet paper and, um, solids. What appears to be a pale, delicate sea creature drifts by. It's a condom. "Someone got busy," one of the crew jokes. The crew's job is to make sure everything flows unimpeded to the treatment plant at Blue Plains. They inspect the sewers, traverse its narrower arteries - not every section is as large as this stretch - and clear blockages that can be caused by things as mundane as a stick, bottle or coat hanger. "It isn't for everybody," Tyrone says of the job. It takes a special person. The crew members joke about contractors who balk at entering the sewers. "One at Fourth and Indiana never even went in," someone says. "Said, "Nah, we're not going down there." " It is a spooky place, and I'm not surprised when someone mentions that another contractor crew reported seeing ghosts in the sewers under St. Elizabeths. "The scary part is, it was a group of them that saw it," says David. Them dudes packed up and never came back. Rats are not uncommon. Once, during a trip down the sewer under North Capitol Street, they saw a rat army - hundreds of the rodents - off in the distance, staring at them. "That was a heck of an experience," David says. When we left out, they were still there, chilling. On this night, we venture only about 700 feet along the sewer, plenty far for me to get the general idea. Smaller tributaries angle in, adding their pungent contributions to the main flow. Then I spot a trickle of water spurting from the wall. It arcs from a tiny eye-level fissure in the brick. I decide I know what this is. It is the creek, or what's left of it, a small bit of "natural" water following the course it has for millennia. It is Tiber Creek, untamed. Come with me To see a video about Tiber Creek and my trip into the sewer, go to washingtonpost.com/ johnkelly. Cheerio I know it seems like I just got back from vacation, but now here I am, going on another. This one takes me to England - to help Daughter No. 1 move into her grad school apartment. My column will return Sept.