My Essential Question

How are different road surfaces chosen for certain roads and what are the pros and cons of each?

I have always found roads as something interesting and have always wanted to stop and watch every step of the process for a road being constructed. Finding the answer to this question will help show me why some roads are concrete, some are asphalt, gravel or even all the new synthetic materials that are on the market today. It will also provide me with some great insight into why engineers choose these certain compounds and what the processes are to create these extraordinary and complex paths of travel. This questions will keep me working hard because of my long past interest and fascination in roads and the machinery used to pave the highways and roads around us.

How Stuff Works... Landfills

The image displayed below is that of a cross-section drawing of a cell in a landfill. These are important to contain leachate which can affect ecosystems in and around areas in which landfills exist. There are many different important parts and layers of a landfill that a lot of people don't know about, because they are not seen. The most important layer is the bottom plastic liner. This keeps anything and everything from escaping into the groundwater. A few of the layers above catch small debris that cannot pass through the water collection system. The next few layers above are composed of garbage and soil in multiple layers to increase the rate of decomposition. 

Many harmful chemicals and gases can be built up or made while trapped under ground together. The drainage system allows for these chemical to pass through into a leachate pond for treatment at a water treatment facility, while harmful gases such as methane are piped out into holding containers until something can be done with them. As you can see many different pieces are crucial at these facilities, and it's the government’s job to make sure that these systems are constantly working properly to ensure the safety of the public and ourselves.

Freudenrich, Craig. How Stuff Works. 2010. 5 December 2010 <http://science.howstuffworks.com/environmental/green-science/landfill6.htm>.