Trash

Sep 18, 2023

The first thing you notice when you pull up to the Hampton/NASA Steam Plant off Wythe Creek Road is the smell.

Plant manager John MacDonald jokes that he doesn't notice it; then he says, "That's the smell of money."

It's also the smell of success: The 32-year-old facility, which converts 240 tons of trash every day into 1.6 million pounds of steam to help power NASA Langley Research Center, has won a 2012 Federal Energy and Water Management Award.

The award recognizes "outstanding contributions in the areas of energy efficiency, water conservation and the use of advanced and renewable energy technologies at federal facilities," according to the U.S. Department of Energy, which sponsors it. This is the first time Hampton and NASA Langley have won.

The trash-to-steam plant is a long-standing partnership between the city and Langley, initiated both as a cost-effective means to generate steam for Langley's wind tunnel operations and better dispose of municipal garbage.

"It's one of the first green initiatives ever," MacDonald said. "It's a win-win situation for both."

How it works

The facility is a relatively low-tech way to power high-tech aerospace and aeronautics research.

All year long, except for a few days when the boilers are shut down for routine maintenance, trucks haul in garbage from Hampton, NASA Langley, Langley Air Force Base and the Newport News Shipyard. Commercial vendors also drop off refuse, for a tipping fee.

Haulers back up to a 30-foot pit on the tipping floor as hydraulic lifts hoist the truck beds to dump all manner of trash. An operator works one of two overhead cranes suspended from the ceiling to constantly move the trash into 60-foot mounds on either side of the pit.

The cranes also feed two boilers located out of sight behind a 60-foot concrete partition, dropping great 1 1/2-ton clawfuls into a feed chute. The trash falls to the stoker, or a moving floor that carries trash through the boiler as it burns to 2,200 degrees F.

The combustion heats 5,255 gallons of water in hundreds of tubes that hang from supports 65 feet in the air and along the walls. Steam forms in the tubes, moving up to a steam drum for export to NASA Langley through a system of pipes and valves.

Bottom ash left on the stoker drops into a water-filled trench, to be ferried out by conveyors. A magnet removes ferrous metals — iron or steel — for recycling.

But the fly ash, MacDonald said, undergoes a process to render it inert, or environmentally harmless.

First, exhaust gases are piped to a tower and sprayed with lime slurry to reduce acid content and temperature. Then they’re filtered through fine mesh bags before fans draw the gases up a 248-foot stack for release into the atmosphere.

Particulates and heavy metals — known as fly ash — that drop from the exhaust stream during that process are carried off by conveyor, combined with the bottom ash and treated with more lime.

Fly ash as a byproduct of coal combustion has concerned environmentalists and health authorities for decades, although the industry disputes the health impacts. Fly ash from burning coal is known to contain trace concentrations of heavy metals, such as mercury, lead and arsenic, which can be harmful in large amounts.

According to MacDonald, the steam plant's scrubbing and filtration process renders fly ash from trash combustion not only inert, but safe enough to be used as a sanitary top cover at the Bethel Landfill in Hampton.

Its fly ash is tested four times a year to make sure it's safe by Virginia standards, he said, which are tougher than EPA standards. The state Department of Environmental Quality also conducts random inspections.

According to MacDonald, for every 100 trash trucks that enter the steam plant, 12 leave carrying ash and incomplete combustibles to the landfill — an 88 percent reduction rate.

More steam, less cost

The steam plant was dreamed up during the energy crisis of the late 1970s, MacDonald said. It was built in 1980 using "very stick-shift" technology by today's standards, but has undergone upgrades over the years.

Most recently, the city said, the plant got a $9 million upgrade to meet new federal Clean Air Act regulations.

It employs a staff of 38 working 12-hour shifts.

Langley uses the steam not only for heating and cooling, but to perform research inside its wind tunnels, according to Stephen Bollman, manager of the center's plant facility operations.

Steam ejectors are far more efficient than electrical mechanical vacuum pumps at drawing out air and creating a vacuum in the spheres that are a crucial component of wind tunnels, he said. Vacuum pumps also take five times as long to do the job, requiring an enormous amount of electricity.

Langley also has a dual-fuel steam plant on its campus, its boilers powered by oil or natural gas. Last year, the research center was able to increase the use of steam from the trash-to-steam plant and thereby reduce the amount produced at its fossil-fuel plant.

Bollman said older 8-inch pipes running between the city and the NASA plant were replaced with 10-inch pipes, bringing it up to code and offering a more stable supply of steam on demand.

As a result, water consumption for steam production at Langley fell by 2 million gallons, and natural gas consumption centerwide fell by 40 percent, saving the facility more than $500,000 in fiscal year 2011, according to a Hampton press release.

The city pays the steam plant about $970,000 annually to dispose of its garbage, MacDonald said. If Hampton had landfilled the trash it sent to the facility last year, it would have cost more than $1 million.

According to Hampton figures, the steam plant has saved the city millions of dollars in landfill costs over the years.

Michael Phelps’ swim trunks

The steam plant offers "tours de trash" for schoolchildren and adults which MacDonald said have proven popular.

"I’m very proud of the plant," he said. "I’m glad to show it off."

Kids are most impressed by the mountain of garbage on the tipping floor, and peering through boiler room cameras to watch objects burn and pop inside the hellfire incinerators.

MacDonald reminds them that the trash they’ve thrown away since 1980 has gone to test space shuttle aerodynamics, explore Mars, build an inflatable lunar habitat and even help swimmer Michael Phelps win gold medals in the summer Olympics.

Phelps’ hydrodynamic Speedos were tested inside a wind tunnel.

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