2007年VOA标准英语-Modern Landfills Can Turn Garbage into Clean En

By Stephanie Ho
Washington
31 May 2007
 

As long as there are people on the planet, there will be garbage.  The rubbish often piles up in landfills that produce a harmful greenhouse gas called methane¹.  VOA's Stephanie Ho reports solid waste managers have been working to turn this methane into something good -- namely, clean energy.

A mountain of garbage looks awful. And it is worse than it looks -- and smells.  Those tons of decomposing² trash are producing methane gas.

Garbage being dumped at a landfill

If allowed to seep³ out into the environment, methane contributes significantly to global warming. Yet it is not all bad. If captured correctly, methane can generate electricity. 

The Environmental Protection Agency says about 400 landfills in the United States have methane power plants.  One of them is the Frey Farm Landfill, run by a local government authority in Lancaster County, Pennsylvania. The E.P.A. considers it a model landfill for the way it pipes methane to a private plant that generates enough electricity for about 4,000 homes.

Gary Platt is the plant's operator. "They bring the garbage in and after the garbage is compacted into the landfill, we draw wells,” he explains. “Wells go down, we put perforated pipe down the center of it, which collects all the methane from the garbage."

The gas plant also produces steam that a local dairy uses to pasteurize its milk and clean its equipment.  The dairy's executive vice⁴ president, John Cox, points to the old diesel⁵-fueled boilers⁶ the dairy used to use. "We estimate that we're going to save 220,000 gallons [833,000 liters] of diesel fuel a year, by purchasing steam from this methodology."

Lancaster County's partner is a local energy company called PPL Energy Services.  PPL business manager Steve Gabrielle says the Frey Farm project is only financially feasible for his company right now because of the government tax credits. "If electric energy prices continue to increase, there might be more of a reason to do these projects without the tax incentives⁷."

Back at Frey Farm Landfill, waste management official Jim Warner says the site will accept trash for more than a decade. "You see, eventually that will be filled, this whole area will be filled in the year 2019.  There will be a nice big circle 80 feet higher [24.5 meters]."

Capturing methane energy after a landfill is capped

The landfill will continue generating methane gas long after it is full.  The problem then -- what to do with the land?

According to Jim Warner, Executive Director of Lancaster County Solid Waste Management Authority, "Once a landfill, always a landfill, for the most part."

Because the waste settles as it decomposes⁸, a landfill is not an ideal place to build homes.  But Warner says the government is exploring other ways to generate energy at the site, using wind and the sun.

"That's one benefit of the landfill, it is open space,” says Warner. “And that is something you need to develop solar projects -- open space to capture the sun.  Right now we have a nice sunny day.  We could be capturing some of this solar energy."

And if they do, they will help the United States, and the rest of the world, meet an ever-growing demand for energy.

1 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

2 decomposing   

腐烂( decompose的现在分词 )； （使）分解； 分解（某物质、光线等）

参考例句：

• The air was filled with the overpowering stench of decomposing vegetation. 空气中充满了令人难以忍受的腐烂植物的恶臭。
• Heat was obtained from decomposing manures and hot air flues. 靠肥料分解和烟道为植物提供热量。

3 seep   

v.渗出，渗漏；n.渗漏，小泉，水（油）坑

参考例句：

• My anger began to seep away.我的怒火开始消下去了。
• If meteoric water does not evaporate or run overland,it may seep directly into the ground.如果雨水不从陆地蒸发和流走的话，就可能直接渗入地下。

4 vice   

n.坏事；恶习；[pl.]台钳，老虎钳；adj.副的

参考例句：

• He guarded himself against vice.他避免染上坏习惯。
• They are sunk in the depth of vice.他们堕入了罪恶的深渊。

5 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。

6 boilers   

锅炉，烧水器，水壶( boiler的名词复数 )

参考例句：

• Even then the boilers often burst or came apart at the seams. 甚至那时的锅炉也经常从焊接处爆炸或裂开。 来自英汉非文学 - 科学史
• The clean coal is sent to a crusher and the boilers. 干净的煤送入破碎机和锅炉。

7 incentives   

激励某人做某事的事物( incentive的名词复数 )； 刺激； 诱因； 动机

参考例句：

• tax incentives to encourage savings 鼓励储蓄的税收措施
• Furthermore, subsidies provide incentives only for investments in equipment. 更有甚者，提供津贴仅是为鼓励增添设备的投资。 来自英汉非文学 - 环境法 - 环境法

8 decomposes   

腐烂( decompose的第三人称单数 )； （使）分解； 分解（某物质、光线等）

参考例句：

• The debris slowly decomposes into compost. 这些垃圾慢慢地分解成了堆肥。
• Plastic is a substance that hardly decomposes in the nature. 塑料是一种在自然中极难降解的物质。