Soil and Land Pollution RAD Guide (Ch.18-19) April 21, 2017

What are 2 ways that exposed rock can be weathered? Mechanically Example: waves on a cliff Chemical Example: rusting

What is bedrock? Why is it important to soil formation? Bedrock: igneous, metamorphic, and sedimentary rock of lithosphere that may exist as mountains, cliffs, or low-lying plains Supplies material needed to build soil

Describe what soil is and how is formed. Soil: mixture of mineral particles, air, H2O, & living and decaying organisms Outer layer of bedrock weathers (cracks and holes) Cracks reach deeper & outer layer becomes broken into small particles Burrowing animals & plant roots break down bedrock & aerate soil VOCAB: parent rock

Describe what a soil profile is and what 4 distinct layers form. Soil profile: a vertical cross section of soil from the ground surface down to the bedrock A Horizon: topsoil B Horizon: subsoil C Horizon: parent rock R Horizon: bedrock

Describe the 3 major soil textures. Sandy: enables soil to drain well but dries out quickly; largest mineral size Clay: flat and traps H2O, preventing H2O drainage; smallest mineral size Loam: mixture of sizes for good drainage and moisture for plants; medium mineral size

Describe the interaction of soil & climate. Desert: small soil profile; large particles Grasslands: thicker soil profile; faster weathering of rock Tropical: very thick soil profile; very fragile soil because of so much rain; a lot of clay in the subsoil

What are the major causes of erosion? Wind and running water

What causes soil loss & desertification What causes soil loss & desertification? What % has undergone desertification? Overgrazing, deforestation, & poor irrigation and cultivation 30%

How much topsoil is lost to water & wind erosion? 2.5 billion tons lost to water 1.5 billion tons lost to wind TOTAL=4 billion metric tons!

Describe the 4 types of soil conservation & land management. Strip-cropping: farmland plowed so plowed strips separated by planted strips Contour Farming: plowing along a slope instead of across it; furrows collect H2O which reduces erosion

Terracing: series of platforms (terraces) are built into the slope; separated by vertical steps Shelter belts: rows of trees planted along outer edges of field

How do we define solid wastes? All garbage, refuse, & sludge products from agriculture, forestry, mining, and municipalities Examples: garbage trash junk sewage scrap refuse

Describe how garbage disposal has changed over the years. Hunter-gatherers: left it and moved on Athens, Greece 500BCE: trashed dumped outside of city walls Rest of Europe dumped in the streets NYC/NJ 1892-1900CE: garbage loaded onto ships and dumped in Atlantic Ocean Now we use landfills

What is a landfill? How much garbage is dumped there? Site where wastes are disposed of by burying them 70%

Why are open landfills no longer allowed in the US? It supported large populations of rats, insects, etc. Foul odor and disease

Describe what a sanitary landfill is & identify 2 problems. Wastes are spread in layers ~3m deep & compacted by bulldozers Soil spread on top of refuse & compacted Repeated until garbage reaches certain heights Methane produced Leaching of toxic substances

What are hazardous wastes? Solid, liquid, or gaseous wastes that are potentially harmful to humans and environment Love Canal, NY: Town built next to old chemical plant Steel containers holding waste leaked Birth defects and cancer affected the people Government relocated them ($190 million)

Name 6 types of hazardous waste. Reactive Waste: can explode Corrosive Waste: can eat through steel, clothing, and burn skin Ignitable Waste: can burn at low temp; toxic fumes when lit Toxic Waste: chemicals that are poisonous to people Radioactive Waste: gives off radiation (given off when mining Uranium) Medical Waste: old medicine, medicine containers, lab equipment and specimens

Identify & explain 4 methods for reducing volume of waste. Recycle: paper, plastic, aluminum, glass, etc. Reuse: cloth diapers Biodegradable: leaves, grass clippings, food waste*, composting Repair: old appliances, shoes, cars

Name 6 ways of disposing of hazardous waste. Waste exchange: use haz. waste in production of other materials Deep Well Injection: inject waste into porous rock under water table; LIQUID Secure Chem. Landfill: waste is stored on nonporous bedrock pipes to monitor and collect leaks; cover with clay

Controlled Incineration: burn waste at high temp Expensive Biological and Chemical Treatment Plants: turn harmful things into harmless Radioactive Waste Disposal: put in H2O or bury underground

What does EPA stand for? EPA = Environmental Protection Agency Established in 1970

Briefly describe Superfund. Law designed to protect communities from dangers of hazardous wastes CERCLA (1980): got $9 billion dollars to implement

What are some countries doing to combat high cost of disposal? Ship waste to developing nations and leave it there Examples: West Africa and Zimbabwe