Student Objectives Use the information gained to make responsible choices in selecting everyday products and services using scientific information Evaluate the impact of waste management methods such as reduction, reuse, recycling, and composting on resource availability. – How will using these methods help reduce landfills?

What do we do with all of this trash?

FYI - Some Statistics Each year, Americans generate nearly 210 million tons of trash. That equates to an average of four pounds of trash per person per day! So what are we doing with all of this trash?

Where does it go? Some of the trash is recycled or incinerated. Incinerated - to burn or reduce to ashes; cremate. Majority of the trash is placed into landfills.

Landfills Two basic types – Open-air Commonly known as dumps. Open hole in the ground where trash is dumped. – Sanitary Use liners to separate trash from the environment. Most landfills cover their trash with compacted soil daily.

Biodegradable vs. Non-biodegradable Biodegradable – capable of decaying through the action of living organisms. – EXAMPLES: food wastes and paper Non-biodegradable – objects, such as most plastics and synthetic materials, do not decay.

FYI - Pros vs. Cons Pros of Sanitary Landfills – Cuts down on smell – Cuts down on the amount of litter – Cuts down on the amount of pests Cons of Sanitary Landfills – Reduces the amount of water and oxygen needed for decomposition – Decomposition occurs at a slower rate

Decomposers Decomposers – bacteria, molds, fungi, and yeast that release enzymes that digest and break down materials into simpler compounds which are recycled back into environment.

Anaerobic Bacteria Bacteria that live in environments that lack oxygen. Decomposition in sanitary landfills is anaerobic. The major byproduct of anaerobic decomposition is landfill gas.

FYI - Landfill gases and the solution… Landfill gas is basically a 50:50 mixture of methane and carbon dioxide gas. Landfill gas is very flammable and explosive and it must be removed from landfills. A series of pipes are embedded in sanitary landfills that collect the gas. The gas is lead through the pipes to the surface where the gas is usually burned.

FYI - The LMOP Landfills are the largest source of human- related methane emissions in the United States The U.S. EPA has a voluntary assistance program that helps to reduce methane emissions from landfills by using the methane for an energy source.

FYI - Dallas' garbage on its way to becoming Dallas' energy 11:52 PM CDT on Saturday, July 12, 2008 By RUDOLPH BUSH / The Dallas Morning News If the plan works, it will essentially turn the landfill into a giant compost pile that could produce enough natural gas to serve the needs of some 16,000 homes. “Even though it looks like we’re just burying trash, it’s really a huge science project,” said Ron Smith, assistant director of the city’s sanitation department. “It’s probably going to end up being the largest in the country.” Now, the city has a plan to make the McCommas landfill the first in Texas to use biotechnology to rapidly produce methane gas

McCommas Landfill 11 th largest landfill in the nation Capable of heating 30,000 Dallas homes. More trash equals more methane Other landfill sites utilized for energy: WMT Lewisville landfill: generates electricity (6MW) WMT Skyline landfill: generates electricity (12MW) - Portions of electricity used for landfill needs - Excess power sold to grid FYI

1. Reduce (Minimization) 2. Reuse 3. Recycle 4. Recovery of energy from waste by composting, anaerobic digestion, incineration etc. 5. Landfilling The Hierarchy of Waste Management