Chapter 19 Land Pollution

Solid Wastes -Solid waste is defined as garbage, refuse, and sludge products from agriculture, forestry, mining, and municipalities. -First garbage dumps were in Athens Greece, around 500 BC -BUT for the most part, the world just dumped their garbage in the streets -In 1892, New York began better sanitary changes, but wasn’t until 1900 that garbage began to be collected. -Typically it was loaded onto barges and dumped into the ocean -Ironically it wasn’t until, after many years, swimmers observed mattresses and dead animals floating past them. -Landfills were the solution (a site where wastes are disposed of by burying them).

Landfills -As populations grew, more and more garbage is produced…where do we put it all? -Open dumping landfills was the first step (not very pretty) -Supported large populations of rats, insects, and other unwanted organisms -Smelled -Rain washed pollutants into the soil and rivers or leached underground -And basically a huge eye sore -“sanitary landfills” became the solution -The idea: wastes are spread in layers about 3 meters deep, compacted by bulldozers, about 15 cm of soil is spread on top, and compacted again. -This continues until a maximum height is reached where a last layer of soil is placed, grass and trees are planted.

“sanitary”, not so “sanitary” -Methane gas is produced by the decay of the materials (can be harnessed and used if built correctly) -Leaching is still an issue, even with the best designs. Hazardous Waste -Solids, liquids, or gaseous wastes that ae potentially harmful to humans and the environment, even in low concentrations. -Examples of effects….(see page 309 for more)

190 million in relief (in 1970)

3600 died, 200,000 injured

Classifications of Hazardous Materials -Reactive Waste: waste that can explode -Corrosive waste: waste that can eat through steel and other materials. -Ignitable waste: can burst into flames at relatively low temperatures -Toxic waste: poisonous to people -Radioactive waste: radiation givin off by mining these materials, medical, and nuclear -Medical waste: old medicines, medicine containers, lab equipment, and lab specimens. -Hazardous home waste: stuff in your home that is hazardous -Ammonia, bleaches, toilet cleaners, oven cleaners, disinfectants, furniture polish….just to name a few.

Top soil erosion -Soil can become unsuitable for planting if: -Overgrazing, deforestation, poor irrigation, and cultivation are practiced or mis-managed -Desertification: type of land degradation in which a relatively dry land region becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife. It is caused by a variety of factors, such as climate change and human activities. -It is estimated that 30 percent of the earth’s land is or has undergone desertification -1/3 of all farmland in the US is threatened by erosion -2.5 billion metric tons of topsoil is washed away by water each year -1.5 billion metric tons loss to wind erosion -Largest concern around the world is soil loss due to water

Effective, but costly and time consuming, less destructive methods: -Strip-cropping: plowed so that plowed strips are separated by planted strips. Always having at least part of the land covered by planted crops. -Contour farming: plowing along a slope, instead of across it. This prevents water from eroding, and aids in collecting excess. -Terracing: platforms are built into the slope or hill. Each is separated by a vertical step. -Shelter Beds: rows or trees are planted on outside edge, providing wind breaks.

Controlling pollution on the land -The best way to eliminate wastes is not to produce them, however, since this seems to be impossible, we need to rely on the three R’s\ -Biodegradable: substances decompose easily and enrich the soil. Example: compost pile -Hazardous waste- most believe there is no safe way to dispose of this. -Waste exchange: taking one person’s/company’s waste and moving it to another who can use it in the production of their goods. -Deep-Well injection: liquid wastes are pumped into deep porous rocks through lined pipes, located well beneath the drinking-water aquifers…nothing bad can happen with this one huh?

-Secure chemical landfill: made in areas with non-porous bedrock, to prevent leaching, covered with clay to keep water out. -Controlled incineration: burning of wastes at extremely high temps degrees Celsius. Very expensive. -Chemical and biological treatment plants: hazardous to non hazardous by using treatment plants, neutralizing the hazardous parts and then disposed of. -Radioactive waste: placed in water, sealed in stainless steel tanks, encased in concrete, then buried deep underground.

Legislation -CERCLA : Comprehensive Environmental Response, Compensation, and Liability Act of Nicknamed “superfund” -Obligations: -Cleaning up hazardous waste dumps -Make polluters pay for it -Develop a national priorities list (most threat) -Take emergency actions where spills or releases have occurred -Encourage the use of the three R’s