The Prisoner - Carlos J. Cortes [48]
“How good are these sewer maps you have?” Nikola asked.
“As good as they come. These are the working layouts of WASA, the D.C. Water and Sewage Authority.”
“Accurate?”
“To a point, but these cover only the upper levels.”
“How many levels are there?”
“No idea, but at least a dozen.” Dennis slowed down, then turned at an intersection.
“No maps?”
“Not even records. Sewers are the weakest spot in most old cities. An army could move through the many forgotten and unexplored levels. The authorities have tried to separate the sanitary and storm systems and have even installed sensors in some new lines—in particular those near strategic areas—but it’s a useless exercise.”
“Why?”
“As I said, only the upper levels are covered. One can install detectors on the ground floor of a house and feel protected. Problem is the many uncharted basements under the property.”
“Yes, but they still have to come up to the ground floor to get to you.”
“True,” Dennis conceded, “but they would be inside the property already. Combined systems is another problem; a nightmare.”
Nikola stared ahead as Dennis maneuvered to overtake a lumbering truck.
“Like many older cities, most of the D.C. sewers were built at the end of the nineteenth century as combined systems to carry, in the same pipe, both sanitary sewage and storm water to the treatment plant.”
“Here in Washington, D.C., I suppose that means the Blue Plains plant.”
“Right. The ideal separate system would channel sewage through one set of pipes, while storm water would flow through a separate set of pipes to the rivers. But old cities rarely have an ideal prototype of anything. Washington evolved as a combined system, with newer, separated networks only in the more recently constructed areas.”
Nikola frowned. “What’s up with a combined system?”
“The system works reasonably well in dry weather, but the main lines can’t hold both wastewater and storm water during heavy rainfall, so they divert the lot into the Potomac and Anacostia Rivers, Rock Creek, and other tributaries.”
“You’re implying the fugitives can make it to the Potomac without ever having to surface?”
“I’m certain there are scores of abandoned tunnels and pipes heading in that direction.”
Nikola nodded absently. Dennis’s details backed his decision not to commit any forces to the sewers. It would have been a pointless exercise. “But the system must have been maintained and renewed, no?” He hoped the network of sensors and security measures had been extended.
“It has. But enlarging a tunnel or pipe is a nightmare. Instead, the engineers have sunk new ones at different levels, often using parts of the old ones. There have been tunnels, private railway lines, shelters, deep stores, you name it, piled on top or below one another.”
As they neared his property, a house isolated in a cul-de-sac, Nikola reached to unfasten his seat belt and paused when the dashboard screen changed color, followed by an insistent beep behind them.
Dennis stopped the van a few feet away from the already-opening wrought-iron gate, then maneuvered the vehicle to the driveway fronting the house. He killed the engine, swiveled his seat, and moved over to his console. After switching off the wireless link to his pad on the dashboard, Dennis brought the equipment online and started scrolling screens, interrogating scores of subsystems. “We had a signal and lost it.”
“Location?”
“Nope. It was a weak signal captured only by a single direction finder. Without a longer broadcast, pinpointing the signal is impossible.”