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Lithosphere and Groundwater
Lithosphere solid rocky crust of the earth rocks on the surface are
classified in 3 types igneous-cooled, molten rock,
granite
Lithosphere Sedimentary- sediments deposited
in water and later made solid. Metamorphic-Igneous and
sedimentary rocks changed by hear &/or pressure Ex: marble, slate
Groundwater groundwater- water occurring
beneath the surface used mostly as well water most occurs within lithosphere water table- the surface of ground
water in a well
Groundwater point in the ground that is
completely saturated with water.
Water fills all spaces between soil and rock particles. (pores)
Groundwater Porosity- portion of the ground
that contains spaces or voids. The total porosity of the material and size and continuity determine the volume of groundwater that is held available.
Groundwater U.S. gets 1/2 of our drinking
water from groundwater
Groundwater Groundwater pollution 1988- EPA published a report 46 pesticides found in
groundwater in 26 states only 9 were in concentrations
higher than health advisory levels
Groundwater World Health Organization
(WHO) each year 1/2 million people are poisoned by pesticides
Groundwater Herbicides & Insecticides are
used in “large quantities” by farmers- one billion pounds of active ingredient per year
Groundwater Nitrates- EPA standard of no
more than 10mg/liter of Nitrate Nitrogen in groundwater used for drinking.
More than 21% of samples contained more than 10mg per liter in Kansas and Rhode Island
Groundwater 10-19% were in excess in
California, Arizona, Oklahoma, and New York
5-9% were in excess in Colorado, South Dakota, Nebraska, Texas, Minnesota, Iowa, Illinois, Pennsylvania, Maryland, and Delaware
Groundwater in all of the other 50 states less
than 5% tested high.
Controlling Groundwater pollution 1990 National Fertilizer and
Environment Research Center set up 20 demo sites to control pesticide and nitrate pollution.
Pierre, South Dakota Cone Ag Service
Problems of greatest concern metallic impurities in
phosphoric acid fertilizer gypsum pond leakage treatment of contaminated soil reducing pollution from liquids
rinsed from application equipment
Problems of greatest concern
microbial techniques for waste treatment
nitrate inhibitors for area techniques for sampling and testing
groundwater developing better containments for
chemigation and fertigation
Pesticides and groundwater most pesticides are synthetic
organic compounds
Processes for loss from soil volatilization decomposition retention by soil transport by H2O
Fumigants relatively volatile vaporize at low temperature and
move as gases through the soil Ethylene dibromide - used for
nematode control
Ethylene dibromide very soluble in water not retained by soil commonly found in ground
water
Synthetic Organics may be decomposed in different
ways many are broken down rapidly
in sunlight
Some pesticides react in water to form new
compounds fungicide Captan reacts rapidly
with water to form a hamless product
Some chemicals decompose very slowly and
may persist for years example - DDT
Organic Matter is the most important soil
particle in binding pesticide in the soil rather than going into the water
Primary transport of pesticides through the soil is
by percolation of water down
Health Advisory Concentrations each of two animals is treated with
a range of doses of the pesticide maximum dosage that produces no
adverse effects in the more sensitive of the two species is divided by a safety factor (100)
Concentrations for a substance for which a safety
factor of 100 has been used a 22 pound child would have to
drink 26 gallons of water with the health advisory concentration per day every day
Continued to ingest an amount of pesticide
equivalent to the max daily intake that produced no observable effect in the test animal of the same average weight
Avoiding pesticides in h2o alternative h2o sources distilling h2o ultraviolet light activated carbon filter
Nitrates and groundwater mostly from plant fertilizers introduction of legumes
(alfalfa) plants that take Nitrogen from
the air and put it into the soil
Nitrates and groundwater commercial fertilizers are used
to supplement naturally occurring nutrients
production of ag crops has increased due to the use of fertilizers
Nitrates and groundwater plants absorb only part of each
nutrient present in the soil as the concentration of nutrients in
the soil increases, % of total amount absorbed decreases
greater residues are left in the soil
Nitrates and groundwater most chemical ions of fertilizers
are bonded to and retained by the soil
Nitrogen is not
Human Health Issues Problems related to Nitrates birth defects cancer migraines
Human Heath Issues nervous system impairment methomoglobinemia
Methomoglobinemia type of anemia hemoglobin carried Nitrogen
instead of Oxygen to the body cells
common cause of infant deaths
Groundwater use over drafts when more water is removed
than is replaced by water from the surface
57% of water resource regions have over drafts
Groundwater use water table is falling in these areas most serious over draft is at the
Ogallala Aquifer nations largest under parts of 8 states