The two pulled over at a guarded checkpoint. Ahead was a tunnel leading under ground. The barriers were raised and they sped in. There was no speed limit here - 100 mph clocked the speedometer. The perfectly straight tunnel led them 50 feet underground to another as wide as a three-lane highway. Dazzling lights zoomed past the windscreen. A pungent smell filled the air. The lower deck of the tunnel transports wastewater from the closest cities. Starting from the populous cities, the tunnel dropped at an angle into a gigantic wastewater storage tank beneath a DC outpost. Gravity did the work. Due to the anaerobic conditions, methane gas forms and passes over the opposing wastewater and flows to the city where it is used for power and heating. The flow of water inland has also helped the seas recover from polluting coastal cities.
"It was ingenious how the engineers built this tunnel. Their machines only drilled through the circumference of the tunnel and then removed the centre part intact." The clock was ticking. The hour that went by felt like forever. There was a battle going on above. Year after year, there would be unrest, and attacks on the outpost were common. Yet, as the project neared its goals, and threatened the balance of the economy, opposition seemed to be on the rise. Pickets were swapped for guns and bombs. Hence, guards like Green were hired to protect the project sites.
"There it is, DC1." The underground tunnels were still a safe refuge. Suresh and Green hurried into the elevator. A sea of people evacuated DC1, rushed their way. To the world, DC supported billions of jobs. To environmental engineers, DC1 is merely a giant wastewater plant. To earth engineers, it is the first true terraforming machine mankind has seen. The reservoir could swallow an aircraft carrier whole. Yet, the vapour inside is a thick cloud of methane from ancient bacteria digesting the waste.
"I hope your fancy wall holds," exclaimed Green as they ascended 150 feet up to the surface. A five-foot geopolymer wall separated them from the wastewater. The desert had plenty of raw material for a structure this massive. As strong as cement, geopolymers phased out Portland cement as a material of choice. Compared to cement, the same amount of geopolymer produces 90% less carbon dioxide and other greenhouse gases. Suresh was confident that his legacy would stand for millennia to come.
The elevator took them past the overflow limit of the reservoir and into the lobby. The sound of guns and explosions rocked the background. A glass panel separated them from the methane power plant section. These massive engines burn the methane-rich gas to power the entire facility. The waste heat treats the colossal amount of biological sludge. Once stabilised, it is applied as a soil conditioner, turning arid desert sands into fertile soil.
Sludge comes from water treatment processes, which then discharge semi-clean water into artificial lakes. The nutrients in the water nourish the bamboo forest while desert sunlight is complementary and year round. The bamboo forest then purifies the water, which flows into veins of artificial rivers. To date, DC has almost achieved its goal. Weather forecasts have predicted rain for the region, something that would have been absurd decades ago.