H|L|P|R|S|T|U|W
H
Hydromodification
Altering or changing the pathway water takes. This is done by channelizing rivers and streams.
Some hydromodification restores creeks to how they once were, but most is forcing the water to
go where humans want it to go rather than where it naturally would flow.
L
Levee
Dirt and/or rock piled next to and parallel to a creek or river.
Levees can be made by nature when rivers flood.
Engineers have copied nature and build levees for flood control or to
help channelize waterways.
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P
Pathogens
Disease-causing agents, particularly living agents, such as bacteria, viruses, molds,
yeasts, and so forth.
We do not want the water we drink to have any pathogens in it. Historically, water has
been the carrier of diseases such as dysentery.
Peat (moss) soil
Dark soil that was formed from the partial decomposition of mosses, trees and other
wetland plants
Pesticides
Poisons we spray on plants, or weed control poisons we put onto the soil. These are
pesticides and herbicides which then can run off into the creeks and rivers. Pesticides kill
insects and other organisms that are animals; herbicides kill plants.
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R
Resource extraction
Removal of natural resources from the earth; mining is a major example of resource extraction.
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S
Subsidence
Compaction of soil that leads to the level of the land being lowered. Withdrawal of
groundwater is a common cause of subsidence. It was been responsible for up to 50 feet of
subsidence in the great Central Valley. In the Delta, subsidence is happening because of the
peat moss-rich soil is decomposing and therefore the land lowers.
Smelt entrainment
Delta smelt (fish) being drawn along with the water that the large Delta pumps are withdrawing
from the Delta estuary. Unfortunately, these entrained fish are then killed as the pumps
grind them to pieces.
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T
Toxicity
Level of poisons in the water. We need to be sure there is nothing in our water that is
poisonous, or toxic. Tests are run on municipal water sources to assure that the water meets
or exceeds the purity levels set by the government. Certain materials are known to be toxic,
to toxicity tests are run for particular chemical, nitrates, perchlorate, etc., which could be
toxic at some level.
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U
Urban run-off
The water that is not soaked into the soil in urban (city) areas and runs off the concrete,
blacktop, and roads and often ends up in the creeks and rivers.
Unspecified point source (also know as non-point source)
This refers to pollution in the water that can not be pinpointed to one particular source.
When several people on your block wash their cars and let the sudsy water flow into a drain which
is marked flows to the creek, it is difficult to determine (at the creek level) where the
pollution came from.
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W
Waste water (municipal and industrial)
The water we use in our homes all flows to the sewer.
That water is polluted and needs to be cleaned before it can be used in any way. It is wastewater.
Industry also produces water that needs to be purified. Municipal waste water is the sewer water
that is produced in our homes, schools, and so forth.
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