ENVS 101 1st Edition Lecture 13 Outline of Last Lecture I. Water on the GroundII. Water Under the GroundIII. Water and SocietyOutline of Current Lecture II. Water under the GroundIII. Water and SocietyCurrent LectureWater Under the Ground continued:Slow moving groundwater has the capacity to dissolve a lot of material:limestone and marble in particular are very susceptible to this dissolving effect. Water is very good at dissolving things because it is actually considered a polar molecule, allowing it to dissolve any sort of ionically bonded compound, because it can stick to these ions and pull themapart. Caves form when groundwater dissolves an underground void.cave formations that are called speleothems are deposited by precipitation of materials from the groundwaterSpeleothems record information about the environment ex. climate of the surface located above these particular formations. The growth rates of these speleothems will vary year to year depending upon what kinds of climate fluctuations are going on in the environment around them. Naturally, with more water, these formations will grow larger, and even at a faster rate than they would during a dry spell.Sinkholes are large dissolution cavities open to the sky Karts topography forms in regions of exceptionally soluble rock, sinkholes and caves will combine to form a small basins, ridges, and pinnaclesthis is best developed in moist, and tropical regions underlain by limestoneWater and Society:Water resources are under threat almost everywhere in the world in terms of These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Quality, which has to do with the purity, and usefulness of waterand Quantity, which pertains to the amount that is availableA reliable water supply is critical for the following:- Human survival, as well as human health- For both industry and agricultural exploits- For environmental servicesIn the late 90's USDA lowered the legal limit of arsenic that could be in water supplies used by people. This was to prevent large companies that were polluting water sources underground such as wells, from also making those sources vulnerable to being polluted as well. By making different sites where water is abundant legal or illegal to take from or drink from, there have been conflicts with people deciding how the water sources left are distributed throughout a community, or even an entire region.On a global scale: crop irrigation demands 75% of the water, Industry demands about 20% and domestic use demands just over 5%Population growth is partly responsible for increasing demand, as are improvements in living standardsthere are 29 countries world wide with suffer from water shortages (450 million people)Water shortage is worst in areas of desert and semiarid climates,with high population, industry, or agriculture,- that have poor regulations- that have inadequate facilitiesInterbasin transfer of water from one drainage basin to another to meet high water demands raises political issues and conflicts and can have environmental impactsThe accessibility of surface water makes them useful resources but highly susceptible to contaminationcontaminants come from:Point sourcesMining, logging and petroleum dischargeIndustrial and landfill effluentsthermal pollution from industrial water useNonpoint sourcesUrban, suburban and agricultural runoff airborne contaminantsexcess plant nutrients from fertilizers and detergents triggers an algal bloom:where algae growth and aquatic weeds get out of controlEutrophication: When the algae die, their breakdown causes oxygen depletion that kills other organisms in the waterGroundwater contamination can be much more difficult to debts, control, and clean uppassive remediation involves relying on natural environmental processes to clean up the siteActive remediation involves intervention by pump and treat processinjecting oxygen, other chemical or organisms (bacteria) to spread the breakdown of