When most people put their garbage on the curb for pickup each week, they give no thought to where it ends up. In the Davis Energy Recovery District, trash takes an unusual route because the district operates the Intermountain West's only burn plant at 3404 N. 850 East - just east of Hill Air Force Base and north of Highway 193.
Here's a brief, layman's explanation of what happens to garbage in the Davis Energy Recovery District:Tipping floor
Garbage trucks dump their loads on the south side of the burn plant. There's a large, 22-foot-deep pit and usually enough stockpile of trash to keep the plant burning for four days. A huge air intake helps contain odors.
Just north of the tipping floor, there's a special area above the furnace where district customers can drop sensitive documents directly into the furnace. The FBI and Utah State Tax Commission are two such customers.
Control room
Computers monitor every phase of plant operations from high above the tipping floor. TV screens monitor the furnace. A huge crane mixes the trash and dumps it in a slot that leads to the furnace. The crane operator works from behind a glass window, always looking for big metal items, like washers and dryers that may have slipped in. Several other workers monitor the plant's vital statistics. There's a backup computer in the water treatment area.
If it looks like the district is running short on garbage, trash is brought in from Weber County's landfill to pick up the slack.
Most plant workers keep fireman's hours, working 12-hour shifts.
Boiler
The middle of the burn plant looks a lot like the inside of a ship. There are ramps, platforms, stairways and tubes everywhere. The air temperature is naturally hot, and treated water is heated by the furnace. With 150 pounds of pressure, the steam is shipped west to Hill Air Force Base. The burn plant provides 15 to 20 percent of Hill's heating energy needs with up to 80,000 pounds of steam per hour.
When Hill needs less steam in warm months, the burn plant has a recovery process to cool and convert the steam back to reusable water.
Furnace
A small glass door allows a view inside the furnace, where the temperature is between 1,800 to 1,900 degrees centigrade. Burn plant operators say white paper, cardboard and plastics burn the hottest. Approximately 350 tons a day are burned.
Ash area
The burn plant's furnace reduces trash volume 90 to 95 percent and reduces mass 40 to 60 percent. For every 10 tons of garbage processed, a ton of ash is all that remains to be hauled to the landfill. Some metals and glass survive the furnace's high temperatures - metals can be salvaged and sorted magnetically. The burn plant doesn't currently handle medical waste.
Air pollution
Operators say the burn plant is the most regulated combustion industry in the country. The burn plant's furnace makes smoke, but after being processed through electrostatic equipment and other pollution control devices, emissions are transformed into hot air. The hot air vapor may be mistaken for smoke during cold months.
Electricity
The plant's steam turbines produce all the electricity needed by the plant, and some excess is sold to Utah Power.
Citizen facility
On Dec. 9, the district opened a new drop-off area at the burn plant. Residents can now dump garbage for $3 per covered load, instead of going to the landfill.