11 1 10 Freshwater less than 1 salt By 2050 1 3 of all people on earth will lack access to freshwater 70 of earth s surface is water but only 2 5 of that whole is freshwater 60 in glaciers and ice caps 10 is found in surface waters including lakes and rivers 30 is found in groundwater but some of it is deep and out of reach 70 used for agriculture o Irrigation 22 used for industrial processes o Cooling water plants o Newspaper processing 8 is pumped into cities and homes for drinking washing and watering Where Water Use Freshwater Issues Quantity Population growth Climate change increased evaporation and instances of drought o Per capita basis is important o Strains on Quantity o Quantity Solution Dams Stores runoff Can produce hydropower Economic growth jobs Help with flood control Improves navigation o Dam problems Disturbs natural water flows Disrupt fish spawning Prevents sedimentation Mississippi River Delta GHG emissions from reservoirs Displaces people Water borne disease risk Methane CO because they flood out regions to form dams o Other solutions Recycling collecting rain in barrels Conservation Desalination Quality o Point source solution pollution identified as coming from a specific location o Nonpoint source solution broad more dissipated not as easy to pinpoint one source of pollution Car emissions contributing to water pollution Power plants Pesticides Runoff Agriculture Waste water Quality Issues Nutrients o Nitrogen and phosphorus contribute to eutrophication o Gulf of Mexico Dead Zone o Combined sewage overflow Under wet conditions contaminated waste water flows out into the river o Metals bioaccumulation buildup of material in fatty tissue biomagnification as you move up food chain material accumulates and magnifies as you go up the chain Potomac Inorganic Pollutants o Salts accumulation at toxic levels o Acids and bases ecosystem damages Organic Pollutants 10 million time increase Infectious agents o DDT cuts back on malaria but has impacts on the environment o Water zooplankton small fish large fish fish eating birds biomagnifications o Direct from water typhoid cholera dysentery polio o Water borne vectors malaria yellow fever o Less developed countries 2 5 billion people lack adequate sanitation about half of these are without clean drinking water o Cholera in Haiti Sediment o Good in small amounts but excess is bad o Declines in oxygen level makes water less clear so less light gets through to oxygen producing species o Obstructs shipping and hydroelectric turbines o Makes drinking water purification tough Controlling Water Quality Issues o Land management for NPS nonpoint source solution o Urban runoff o Agriculture o Examples o Riparian buffers trees and grass filters to catch sediment o Permeable surfaces Pavement doesn t absorb water more runoff less deep infiltration for ground water o Limiting o Airborne pollutants coal power plants emit large amounts of mercury o Chemical use reaching waterways DDTs pesticides etc o Modification of waterways