Presentation on theme: "There are 3,091 active sanitary landfills in the U.S. and over 10,000 old municipal landfills (rubbish pits)."— Presentation transcript:
There are 3,091 active sanitary landfills in the U.S. and over 10,000 old municipal landfills (rubbish pits).
RubbishPitLandfill Rubbish Pit vs. Landfill
AnatomyofLandfill Anatomy of a Landfill Modernsanitarylandfillsare carefullyengineeredstructures designedtoisolategarbagefrom nearbywatersoilwildlifeand people Modern sanitary landfills are carefully engineered structures designed to isolate garbage from nearby water, soil, wildlife, and people.
HowisSanitaryLandfillmade How is a Sanitary Landfill made? The cavities are dug out of the ground and then the walls are sealed with layers of clay and coated with plastic to prevent groundwater contamination from wastewater that accumulates.
The Liner Note the overlapping seams!
Today's landfills are designed to stay dry inside, except for liquids that ooze from some garbage, and rainwater that trickles through. As water trickles through a landfill, it dissolves chemicals and other particles, creating a liquid called "leachate."
There are four critical elements in a secure landfill: a bottom liner a leachate collection system A gas recovery system and a cover the natural hydrogeologic setting There are four critical elements in a secure landfill: a bottom liner a leachate collection system A gas recovery system and a cover the natural hydrogeologic setting Each of these elements is critical to success. The natural setting can be selected to minimize the possibility of wastes escaping to groundwater beneath a landfill. The three other elements must be engineered. Each of these elements is critical to success.
CrossSectionofLandfill Cross-Section of a Landfill
Cross-section of a sanitary landfill
The state-of-the-art system, constructed at the bottom of the landfill, has a special double-liner to prevent leachate leakage. The contained leachate is run through pipes to above-ground storage tanks and hauled for treatment and disposal at a large regional wastewater treatment plant. WhatisdonewiththeLeachate What is done with the Leachate?
detection meters between the liners which are monitored continuously monitoring wells around the site which are sampled quarterly to test the groundwater quality Even though there are 2 liners that overlap to keep leachate from leaking out there is always that slim chance. So to help protect the public, landfills are also designed with:
Landfills first existed as rubbish pits with NO protection from leachate getting into the groundwater. Next there came an improvement where a landfill had a clay liner. This afforded some protection, but not much. Now landfills are required to have both a clay and plastic liner plus a leachate collection system to protect the groundwater from possible contamination. Groundwater Protection
The Capping of a FULL Landfill
Not really. Landfills are mostly anaerobic. Without the oxygen and water needed to break down organic materials, all garbage decays very slowly in a landfill. This means our garbage will probably be around for a very long time. right So...landfill garbage degrades, right?
40 Yr-old Newspaper found in Landfill
Even food does NOT degrade
AmountofTrashThrowninLandfills Amount of Trash Thrown in Landfills byweight (by weight) AmountofTrashThrowninLandfills Amount of Trash Thrown in Landfills byweight (by weight)
Plastics Plastics can take between years to degrade. Only 3% of it is currently recycled. YardWaste Yard Waste “Green Waste” (leaves, twigs, Christmas trees) can be shredded and used as mulch or composted. PaperCardboard Paper & Cardboard Nationwide, paper & cardboard account for 41 % of all municipal solid waste. Only about 34.5 % is recycled in the U.S. compared to 40% in Sweden and 50% in Japan.
Metal Recycling aluminum reduces both air and water pollution by more than 95% due to less energy needed to mine & process it. Only 38% of cans are recycled. Glass Glass was one of the first to be recycled and continues to lead all others in % recycled. It is the easiest recycled material to use and is the most cost efficient. FoodWaste Food Waste 15.8 million tons of food goes to waste in the U.S. every year. Vegetable & plant matter can be composted (NOT meat or fats) and used for mulch.
Top 10 Landfill Issues 1. Leakage through plastic membrane 2. Water Contamination from leachate 3. Air Emissions (methane & other gases) 4. Remediation of old toxins in landfills 5. Old municipal landfills contain hazardous waste 6. Location of old landfills needing remediation close to large bodies of water 7. Landfill cover usually is ash from incinerators, not dirt 8. Monitoring of closed landfills will not be kept up 9. Detection of old trash dumps 10. Who is liable when land changes hands?