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Just what is that bullet-shaped object on the grassy knoll at the District end of the Theodore Roosevelt Bridge?

The question certainly flushed out JFK conspiracy theorists. Jack Ecks decrees it a monument to a mythical “Brotherhood,” a secret society dedicated to safeguarding the country. When the agony of Addison’s disease became too much for JFK to bear, Ecks fantasizes, Kennedy “suggested a solution that the Brotherhood carried out on the 22nd of November, 1963. The knoll and the trees symbolize the location of the snipers who ended the president’s pain. The bullet, their tool. Lee Harvey Oswald was a strange coincidence that even the Brotherhood has yet to solve. The rest is history.”

Michael Cookman also theorizes that Kennedy killed himself. But Cookman imagines him resurrected and inside the giant cartridge, “masterminding a plot to turn all world leaders into Kennedys, with the ultimate goal of making Mayor Marion Barry look bad in front of the media.”

My god, man. It’s working!

If these hypotheses aren’t enough to make you wonder what’s in the water, Jim Bellis exclaims: “Starting with a couple from the Slovak Philharmonic in 1972, there have been a series of unexplained disappearances of violin virtuosos from the Kennedy Center. A renegade cell within the CIA has been using alien husbandry technology to breed violinists in a secret facility under the grassy knoll. Thousands of zombie violinists are set to emerge after years spent practicing maddeningly difficult variations on a theme by Paganini. They’ll play their insane serenade through the streets, driving the Washington establishment stark raving mad! The silver bullet, is, of course, the vent pipe for the underground breeding facility. It’s remained in clear view all these years in silent mockery!”

Beneath every rant is a nugget of truth. The bullet is a vent, not for a hatchery of V virtuosos, but for the backup generator of the Department of Public Works’ (DPW) Potomac Sewage Pumping Station.

The reason you never noticed a pumping station from atop the TR Bridge, or from Rock Creek Parkway below, is because the cavernous facility—complete with five pumps the size of small houses; giant block-and-tackles; the above-mentioned generator; banks of valves, switches, and gauges; all bisected by three gargantuan sewer lines—is skillfully concealed inside the base of the bridge.

“We tried to make it inconspicuous,” notes Otto James, chief of the Bureau of Sewer Services, noting that the only thing visible from the parkway is a set of three roll-up, garage-style doors embedded in a hillside.

DPW’s little ruse almost worked. Carlton High, a DPW worker on duty on Feb. 14, says he can’t remember any inquiries about the pumping station, or his job. (Though the latter may be the cross you bear when you work with sewage.)

High and a co-worker form one of three shifts that man the station 24 hours a day. Their job is to regulate the flow of city sewage to the treatment facility at Blue Plains near Bolling Air Force Base. “The plant was supposed to be automatic,” muses High. “But you know how that is.”

Behind the door farthest from the Kennedy Center lies the generator; its vent disappears through the ceiling, emerging on the knoll above. Behind Doors 2 and 3 lies the pumping station itself. The overall effect is that of the engine room of an aircraft carrier, an impression perhaps heightened by High, who resembles a muscle-bound Seabee mechanic.

Of the three sewer lines that run into the station, one brings waste from as far away as Dulles International Airport. Another follows the path of Rock Creek Park. A third, smaller line handles overflow from the major pumping station near Washington Navy Yard; a balloonlike object inside inflates and deflates, allowing sewer central to regulate the overflow. The station’s five pumps have the combined ability to pump 460 million gallons of sewage each day.

Asked if there’s anything about the facility that people would like to know, High brightens and says: “Well, from here we pump the sewage right under the Tidal Basin. That might surprise people!”