Presentation on theme: "December 3, 2008 WASHINGTON – The Environmental Protection Agency yesterday approved a last-minute rule change by the Bush administration that will allow."— Presentation transcript:
2 December 3, 2008WASHINGTON – The Environmental Protection Agency yesterday approved a last-minute rule change by the Bush administration that will allow coal companies to bury streams under the rocks, dirt and sludge from mining.A 1983 rule prohibited dumping fill from mountaintop removal mining within 100 feet of streams. In practice, the EPA hadn't been enforcing the rule under the Bush Administration. Government figures show that 535 miles of streams were buried or diverted from 2001 to 2005, more than half of them in the mountains of Appalachia. Along with the loss of the streams has been an increase of erosion and flooding.The 11th-hour change before President Bush leaves office would eliminate a tool that citizens groups have used in lawsuits to keep mining waste out of streams. Mining companies had been pushing for the change for years.In approving the change in writing as required by law, EPA Administrator Stephen Johnson rejected the appeals of environmentalists and some coal-country officials, including Kentucky Gov. Steve Beshear and Tennessee Gov. Phil Bredesen.
4 In March, 2009, the Obama Administration began re-examining mountaintop-mining permits issued under Bush, putting a hold on six permits that had been issued, and announcing that as many as 200 other permits would also be scrutinized for their environmental impacts.The administration also announced it was reversing the Bush 2008 Rule that had weakened restrictions on mountaintop mining near water bodies. Mountaintop mining, environmentalists say, has now smothered more than 1,200 miles of streams in Appalachia.
5 Water: Resources and Pollution Water Availability and UseWater PollutionWater Quality TodayWater Legislation U. S.World Problems
6 1. Water Resources Water covers 75% of Earth’s surface Oceans: 70% Ice & Snow: 4%Rivers, Lakes, Wetlands: < 1%
7 Major water compartments > 97% of world’s water is saline ocean water< 3% of world’s water is fresh87% of this is in glaciers, ice caps, and snowfields12% is in groundwater< 1% of freshwater is surface water (lakes, ponds, rivers, streams) (this is 0.02% of all water on Earth!)
9 Fresh Water Resources Depend on Precipitation Patterns [Creates water-rich & water poor countries] Figure 10.2
10 Groundwater Largest reservoir of liquid fresh water Aquifers - Porous layers of rock holding waterArtesian - Pressurized aquifer (springs, etc)Recharge Zone - Area where water enters an aquiferRecharge rate is often very slowGroundwater is often removed faster than rechargeZone of Aeration - Upper soil layers that hold both air and water.Zone of Saturation - Lower soil layers where all spaces are filled with water.Water Table - Top of Zone of Sat
11 Surface & Groundwater supplies interact in many ways Precipitation —> Recharge zoneRunoff —> Stream flowDischargeAquiferWater table
13 2. Water Availability & Uses Surface Water (Renewable)~80% of human supplySubject to great variation in dry regions, such as the western U. S.Groundwater (Nonrenewable?)~20% of human supply (but > 40% in U. S.)Many aquifers are now subject to overdrafts (used at rates which exceed recharge rates)(some aquifers used at rates up to 20x faster than recharge)
14 Water Use & Distribution: ~70% of world’s water is used for agriculture~20% is used by households~10% is used by industrySome terms:Withdrawal - Amount of water taken from a sourceConsumption - Water not returned to its sourceDegradation - Contamination making it is unsuitable for desired use
15 Worldwide, agriculture claims about 70% of total water withdrawal In many developing countries, agricultural water use is extremely inefficientWorldwide, industry accounts for about 10% of all water useCooling water for power plants is single largest industrial useFigure 10.8
16 Worldwide Water Availability & Use WHO estimates that people require 1000 m3 per person per year (265,000 gallons!)Big problem is uneven distributionEvery continent has regions with scarce rainfallNatural drought cycles create temporary shortagesClimatic changes (global warming) may alter suppliesUN estimates that 2/3 of world’s population will be living in water stressed countriesIn Lima, Peru a poor family uses 1/6 the water of a typical American family and pays 3x more for water
17 a. World Freshwater Shortages 1 billion people lack adequate supplies of safe drinking water (typically carry water from distant source to home)2.5 Billion lack adequate sanitation45 countries face serious water stress (= lack of adequate supply) (mostly Africa & Middle East)
19 Water5 to possibly 25% of global freshwater use exceeds long-term accessible supplies (low to medium certainty)% of irrigation withdrawals exceed supply rates and are therefore unsustainable (low to medium certainty)
20 b. Surface Water Depletion Dams / ReservoirsHuge evaporation lossesSiltation —> storage capacityUpsets natural balance of water systemsEcosystem Losses (wetlands, riparian)Loss of wildlife habitatLoss of free flowing river ecosystemsDiversion systems drain & destroy aquatic systems and their ecological services
21 Evaporative losses from Lake Meade and Lake Powell is 264 billion gallons per year (>300 billion gal per year for Colorado River). – More water than the entire County of San Diego uses!
22 A reservoir that has become completely filled with silt in Egypt
23 The Aral Sea is drying up and dying as a result of diversion of water for agriculture (courtesy of Philip P. Micklin).
24 From Science Vol 334 p303 – 2011: TASTUBEK, KAZAKHSTAN—At a fishing camp near this village on the Northern Aral Sea, a dozen small boats recently returned to shore bathed in a soft morning light. Their nets bulged with carp, pike, flounder, perch, and a half-dozen other species, all edible and ready for sale. It was a scene unimaginable just 6 years ago, when the Aral—once the world's fourth-largest lake—had shrunk to one-tenth of its original size. Soviet-era planners had diverted most of the water that flowed into the lake from two rivers to irrigate cotton, creating three smaller lakes that became too salty for most fish. Catches that once totaled more than 50,000 tons a year plummeted to just 52 tons in 2004.Aral redux. More freshwater in the Northern Aral (above, at top) has enabled fishers to once again pick a rich catch out of their gill nets (left).Now, since the 2005 construction of a $65 million dike, the northern part of the Aral has become a remarkably healthy fishery. The biomass, or weight of all the fish in the Northern Aral, has soared from an estimated 3500 tons in 2005 to 18,000 tons today, says Zaualkhan Yermakhanov, the Kazakh government's regional fisheries director. “And it's still growing.”“It's been an amazingly fast recovery,” says Philip Micklin, a retired geographer from Western Michigan University who has been studying the Aral Sea since the 1970s. During an expedition last month around the Rhode Island-sized lake, Micklin found that salinity levels have dropped and oxygen levels increased since the Kazakh government, backed by the World Bank and other donors, built the 13-kilometer earthen dike along the Northern Aral's southeastern edge. The dike traps water from one feeder river, the Syr Darya, and has raised the lake's water level by 2 meters and expanded its surface area by some 900 square kilometers (Science, 14 April 2006, p183). During his expedition, Micklin found that the fresh water had reduced salinity from 12.3 grams of salt per liter in 2005 to 8 grams and increased water clarity. As a result, not only are fish becoming more abundant, but aquatic plants and reeds are spreading fast.Prior to construction of the dike, only a hardy flounder introduced from the Black Sea was able to survive in the northern part of the lake. Now, about two dozen species of native freshwater fish that high salinity had driven into the Syr Darya's delta and adjacent lakes have returned to deeper waters and are reproducing at a rapid clip. And the rebound has been even bigger than World Bank planners expected: In the early 2000s, says the bank's Masood Ahmad, a feasibility study had concluded that a revived Northern Aral would ultimately produce about 2000 tons of fish a year—but fishing fleets are already catching nearly twice that amount. To make sure the stocks continue to flourish, Yermakhanov says he is committed to limiting yearly catches to about one-third of the total biomass—much less than what is allowed in many managed fisheries. “I know we could fish more,” he says, “but I want to make sure we can grow the biomass to at least 40,000 tons.”Kazakhstan, flush with income from oil and minerals, is now considering taking the rescue effort a step further. One project, backed by Yermakhanov and local fishers, would raise the dike enough to increase water levels by more than 6 meters, expanding the lake surface by about 50%, to 5000 square kilometers. That plan “would be the best for the ecosystem,” Micklin says, but it isn't as politically or economically attractive as an alternative. That would involve digging a canal to bring water back to the historic port of Aralsk, which was left high and dry by the desiccation. The canal plan “would benefit more people,” Micklin says. For the moment, however, “there isn't enough water flow for both.” The government announced last month that it would appoint an expert panel to decide between the two options.
25 c. Groundwater Depletion Local depletion —> Cone of depressionBroad scale depletion —> Aquifer depletionOgallala Aquifer - Great PlainsAll large desert cities have depleted aquifersPhoenix, Tucson, Las VegasConsequences:—> possible land subsidence, saltwater intrusion—> pollution of groundwater in areas of developmentDevelopment in aquifer recharge zonesIncreased potential for pollution of groundwater“Paving over” recharge areas reduces replenishment
28 Groundwater level changes as a result of pumping in the Texas-Oklahoma High Plains region. (Source: U.S. Geological Survey).
29 d. Water Management & Conservation Domestic conservation~ 1/2 of all water use is “wasted”Largest domestic use is toilet flushing! (Fig )Significant amounts of water could be recycledAgricultural water conservationAgric. is largest user (2/3 of total use)Irrigate at the right timeUse conservative systems (e.g., drip irrig.)Correct pricing structures
30 Price mechanisms and water policy In U.S., water policies have generally worked against conservationSurface ownership rights (Eastern U.S.) or Prior appropriation rights (Western U.S.)Promotes “use it or lose it” attitudesDam and distribution system costs have been heavily subsidizedCharging real costs would conservationIn well-watered eastern states, water policy was based on riparian use rights.In drier western regions where water is often a limiting resource, water law is based primarily on prior appropriation rights.
31 3. Types and Effects of Water Pollution Water pollution = Any physical, biological, or chemical change in water quality that adversely affects lifePoint Sources - Pollution from specific locationsFactories, Municipal sewageNon-Point Sources - Scattered or diffuse (no specific location of discharge)Agricultural fields, Air pollution
33 a. Types (classes) of water pollution Infectious PathogensSources: improperly treated human waste, agric. runoff (e.g., feedlots)Impacts: billion people in LDCs lack adequate sanitation —> water contamination~ 1 billion people lack clean drinking water ~ Cause 80% of all diseases in LDCs ~ 25 million deaths/year (if you include malaria, and yellow fever)More than 500 pathogenic bacteria, viruses, and parasites can travel from human or animal excrement through waterIn developed countries, sewage treatment has virtually eliminated pathogens from waterDrinking water disinfected via chlorination
34 Sources: Agric. runoff, sewage 2. Biological Oxygen-Demanding Wastes = Organic matter that is readily decomposedSources: Agric. runoff, sewageImpacts: bacteria —> O2 —> Aquatic lifeO2 is removed from water by respiration (decomposer bacteria)Water with < 2 ppm dissolved O2 will support only detritivores and decomposers
35 Oxygen Sag - O2 levels decline downstream from a pollution source as decomposers metabolize waste materials
36 3. Plant Nutrients = Nitrates, phosphates, etc Sources: sewage, runoff, air pollutionImpacts: ‘algal bloom’ —> light —> algae death —> O2 —> Aquatic lifeEutrophication - Process of increasing nutrient levels and biological productivityOligotrophic - few nutrients (clear water with low biological productivity)Eutrophic - nutrient rich water (high productivity)
38 4. Toxic Inorganic Pollutants Include:Toxic metals such as mercury, lead, cadmiumSalts, acids, bases (in high concentrations)Sources: industrial wastes, mine runoff, homes (e.g., lead in pipes)Impacts: water quality ( uses), Aquatic life (metals bioaccumulate)
39 5. Organic ChemicalsInclude: 1000s of natural and synthetic organic chemicals found in pesticides, plastics, pigments, oil, etc.Sources: Industrial and household wastes, runoff of pesticides from high-use areasImpacts: water quality ( uses), Aquatic life (many organic molecules bioaccumulate)
40 6. Sediments = Insoluble suspended matter Sources: runoff (soil), sewage, atmos. dustHuman-induced erosion and runoff —> sediments (greatest single cause of water pollution)Impacts: light —> Psn —> Food ChainsAlso smothers benthic life and spawning areas
41 b. Water Quality TodayMajor success story (Legislation that works plus EPA oversight)In 1950s, many rivers/lakes badly polluted (some rivers caught on fire from oil poll.!) (Lake Erie had virtually no fish)In 1999, EPA reported 91.4% of all river miles and 87.5% of all lake areas suitable for their designated usesClean Water Act (1972) established a National Pollution Discharge System which requires a permit for any entity dumping wastes in surface waters.
44 Clean Water Act (1972) established a National Pollution Discharge System, which requires a permit for any entity dumping wastes in surface watersDischarge permits are required for all point sourcesNo discharge allowed for 126 priority pollutantsGoal was to return all U.S. surface waters to “fishable and swimmable” condition (these are the 2 key criteria established by CWA)
45 Major areas of progress: Most progress due to municipal sewage treatment facilitiesIn 1997, EPA switched regulatory approaches: Now focus on watershed-level monitoring and protectionStates are required to identify waters not meeting water quality goals and develop approaches to meet water quality goals
46 Remaining Problem Areas (Local & Global) Greatest problems are from non-point sources: include sediments, nutrients, and pathogens3/4 of water pollution in the US comes from soil erosion, agricultural and urban runoff, and air pollution depositionFeedlots produce 144 million tons of waste/yearAtmospheric Deposition - Contaminants from air deposited into watersheds or directly onto surface watersGreat Lakes estimated to contain > 1 million pounds of the herbicide atrazine
47 Groundwater contamination: Half the US population (95% of rural pop.) rely on aquifers for drinking waterFor decades, seepage has contaminated aquifers~1 trillion gallons of contaminated water seep into the ground every dayFertilizers and pesticides contaminate aquifers and wells in rural aquifersOil, & MTBE is present in many urban aquifersLargest aquifer in San Diego Co. is contaminated with oilNatural gas extraction contaminates aquifers with dozens of unknown chemicals (thanks to Bush loophole in water laws)
49 Drinking water:1.5 million Americans fall ill from fecal contamination annuallySome pathogens resistant to treatmentCryptosporidium outbreaks
50 Ocean Pollution:6 million metric tons of trash and litter tossed from ships into the ocean annuallyMost coastlines contaminated by oil & pollution
51 The ocean’s garbage patches Charles Moore founded the Algalita Foundation in 1998 after sailing a catamaran from Hawaii, which took him through the Great Pacific Gyre“It began with a line of plastic bags ghosting the surface, followed by an ugly tangle of junk: nets and ropes and bottles, motor-oil jugs and cracked bath toys, a mangled tarp. Tires. A traffic cone. Moore could not believe his eyes. Out here in this desolate place, the water was a stew of plastic crap.”There is 6 times more plastic than plankton in this area, which is twice the size of Texas
55 Water pollution problems in other countries: In Russia, only about half of the tap water supply is safe to drinkIn urban areas of South America, Africa, and Asia, 95% of all sewage is discharged untreated into rivers2/3 of India’s surface waters dangerous to human health2/3 of China’s surface water is unsafe for humans