Where does our trash/waste go??

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1 Where does our trash/waste go?? Landfill a designated place to bury trash. Incinerator a designated place to burn trash.

2 Landfill vs-trash Incinerator Landfill can be used in areas with more space. Our Loudoun County Landfill is over 500 acres of land. Incinerator usually in areas with limited space, like in a big city. Covanta is an incinerator in Alexandria that serves the D.C/Arlington/Alexandria areas.

3 Landfill vs-trash Incinerator Landfill trash is buried and stays in the ground. Liners are placed in the bottom of the landfill to prevent trash and leachate from seeping into the groundwater and surrounding areas. Incinerator trash is burned, so there is ash left over after burn is complete. The ash left over still needs to be disposed of (usually hauling offsite) and this ash can be hazardous to the soils and groundwater if not disposed of properly. However, the amount of ash is much less compared to the amount of trash.

4 Landfill vs-trash Incinerator Both a landfill and a trash incinerator can produce their own energy for electrical purposes and the landfill can produce water if it cleans and filters the leachate water. Landfill can produce its own energy from the methane gas collected from buried trash Incinerator can produce its own energy from the steam created during the cooling process, steam is then run though a turbine to produce energy.

5 Proposing the Landfill Before a city can build a landfill, an environmental impact study must be done on the proposed site to determine: area of land necessary for the landfill the composition of the underlying soil and bedrock the flow of surface water over the site the impact of the proposed landfill on the local environment and wildlife the historical or archaeological value of the proposed site Once the environmental impact study has been completed, permits must be obtained from the local, state and federal governments.

6 Parts of a Landfill Bottom liner system - separates trash and subsequent leachate from groundwater Cells (old and new) - where the trash is stored within the landfill Storm water drainage system - collects rain water that falls on the landfill Leachate collection system - collects water that has percolated through the landfill itself and contains contaminating substances (leachate) Methane collection system - collects methane gas that is formed during the breakdown of trash Covering or cap - seals off the top of the landfill Each of these parts is designed to address specific problems that are encountered in a landfill. So, as we discuss each part of the landfill, we'll explain what problem is solved.

7 Also places to drop recyclable materials and methane pipes and a burner to release methane gases. Parts of a Landfill

8 What Happens to Trash in a Landfill? Even after a landfill is closed, the trash buried there will remain. Trash put in a landfill will stay there for a very long time. Inside a landfill, there is little oxygen and little moisture, so trash does not break down very rapidly. In fact, when old landfills have been excavated or sampled, 40-year-old newspapers have been found with easily readable print. Landfills are not designed to break down trash, merely to bury it. When a landfill closes, the site, especially the groundwater, must be monitored and maintained for up to 30 years!

9 Info about our Landfill here in Loudoun County Covers 550 acres of land (only 193 acres are still available for disposal of garbage). Opened in 1971 and is projected to close (run out of room) in about years. 300,000 tons of municipal solid waste (our trash) are collected from the county per year. 100,000 tons of construction debris/yr is collected. It also collects vegetative material (old Christmas trees, etc).

10 Info about our Landfill here in Loudoun County The biggest customers are homeowners. It costs a minimal fee to dump trash, but recycling is free to anyone in the county. As trash is dumped in the landfill it is covered with 6 of dirt each day and a tarp is put on overnight. Has ~65 extraction wells that suck methane gas out of the buried trash currently they are burning it off, but will soon be collected it and selling to electric companies. They monitor wells around the property and have groundwater wells around property that get monitored as well. (To prevent leachate from getting into the groundwater and spreading to other sites).

11 QUIZ Time How much waste does each American throw out per day? 3 pounds (1.4 kilograms) 4.6 pounds (2.1 kilograms) 6.5 pounds (2.9 kilograms) According to the EPA, each American throws away 4.6 pounds (2.1 kilograms) of waste per day. That's about 1,643 pounds (745 kilograms) of trash a year.

12 QUIZ Time The bulk of waste generated in the United States falls into what category? paper food scraps plastic More than a third of the waste Americans throw away each year is paper. Plastic and food scraps both comprise about 12 percent of the overall waste.

13 QUIZ Time To extend the life of a landfill, it's necessary to increase air space. What is one way to increase the space? combust paper compact waste into cells build trash tiers Heavy equipment compresses a day's worth of trash into areas called cells, which are then covered with soil and recompacted.

14 After a landfill closes, how long must it be monitored? 10 years 20 years 30 years QUIZ Time Since landfills are designed to bury trash and not to break it down, toxic chemicals can easily leak out and contaminate the surrounding environment. Closed sites must be monitored and maintained for up to 30 years.

15 QUIZ Time Landfill gas, a byproduct of the anaerobic breakdown of trash, contains primarily which two compounds? methane and carbon dioxide methane and nitrogen carbon dioxide and sulfur When bacteria break down trash, the result is a gas that's about 50 percent methane and 50 percent carbon dioxide.

16 When was the first true sanitary landfill built in the United States? QUIZ Time California's Fresno Sanitary Landfill, built in 1937, was the first landfill in the nation to use layering and compaction.

17 QUIZ Time What's the difference between landfills and compost piles? landfills are bigger landfills smell better landfills preserve trash in its near original state Compost piles are designed to break down trash and turn it into usable nutrients. Landfills, with their plastic liners and oxygen barriers, actually preserve trash.

18 What might be used to help speed the breakdown of landfill trash and produce more methane? composting agents fertilizers bioreactors QUIZ Time New technologies called bioreactors can facilitate the decomposition of trash, thus producing more methane for capture as energy.

19 QUIZ Time Which of the following is required before a landfill can be built? referendums environmental impact studies fundraisers Environmental impact studies determine how much land a landfill would need, the composition of the site's underlying soil and bedrock, the flow of water near the area and the impact a landfill would have on the surrounding environment.

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