Water Scarcity - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 102

tumbled down a 503-foot-deep shaft in Queens, in 1993. But it remains a dangerous
place.
Building their aqueducts two thousand years ago, Roman engineers used fire and
water to crack rock and removed the shards with horse-drawn wagons. Building the first
stage of Tunnel No. 3, sandhogs relied on technology only marginally better: dynamite,
picks, and brute force, or “drill and blast.”
Since 1992, hogs have used tunnel-boring machines (TBMs), better known as moles,
to drill through the rock. A typical mole is seventy feet long and trails another seven
hundred feet of equipment, including a machine shop and a dining car. The machine
weighs 230 tons and has to be lowered into a shaftway in pieces by a special crane
and assembled underground. Computer-operated and laser-guided, the mole is outfit-
ted with giant hydraulic arms that grab the tunnel walls and propel its cutting face into
the granite. At its front is a round shield studded with twenty-seven cutting blades, each
of which weighs 350 pounds. While the hydraulic rams push the snout of the machine
into the rock face, the shield spins and the blades shred the schist with a deafening caco-
phony. A conveyor belt carries the resulting gravel away to the rear and unloads it into
muck cars. The muck is hauled to the surface and trucked to a landfill in New Jersey.
Before 1992, it took eighty sandhogs a full day to drill and blast through twenty-five
to forty feet of bedrock. Now, a mole cuts through ity-ive to a hundred feet in the
same time.
Tunnel No. 3 has taken six times longer to build than either of the first two tunnels,
mostly because of financial and political, rather than geological, challenges. In the early
1970s, cost overruns totaling millions of dollars led to a lawsuit by the city against a
consortium of contractors, which delayed work. In the mid-1970s, the project was again
halted while the city extracted itself from bankruptcy. In 1981 work resumed sporadic-
ally. But by then, New York's increasing thirst had led the DEP to send 60 percent more
water through Tunnels No. 1 and No. 2 than they were designed for. Meanwhile, cor-
ruption plagued the Board of Water Supply , a now defunct body that oversaw construc-
tion, further slowing progress. Worried that Tunnel No. 3 was suffering death by a thou-
sand cuts, city executives beseeched federal officials to step in and finance the project;
Washington declined. In the 1990s, work again resumed, but NUMBY, or “not under
my backyard,” protests erupted in Manhattan and Queens, where residents held signs
aloft saying DON'T GIVE US THE SHAFT ! to protest the building of access shafts and the use of
dynamite in their neighborhoods.
Finally, in 2001, Mayor Bloomberg took a personal interest in Tunnel No. 3. He told
a 2006 press conference that his administration had devoted $4 billion to the new tun-
nel , or “double what's been invested by the last five administrations combined.” During