Acidity of water is
its quantitative capacity to react with a strong base to a designated pH.
Acidity is a measure of
an aggregate property of water
Acidity is a measure of an aggregate property of water and can be interpreted in terms of
specific substances only
Alkalinity is also known as
the buffering capacity of a stream
how well it can neutralize acidic pollution and resist change in PH
the amount of alkaline compounds in the water, such as carbonate, bicarbonates and hydroxides. these compounds are natural buffers that can remove excess hydrogen, or H+, ions
The Biological Oxygen Demand
the amount of oxygen consumed by bacteria in the decomposition of organic material.
BOD also includes
the oxygen required for the oxidation of various chemical in the water, such as sulfides, ferrous iron and ammonia.
dissolved oxygen test tells you
how much oxygen is available
BOD test tells you
how much oxygen is being consumed
BOD is determined by
measuring the dissolved oxygen level in a freshly collected sample and comparing it to the dissolved oxygen level in a sample that was collected at the same time but incubated under specific conditions for a certain number of days.
The difference in the oxygen readings between the two samples in the BOD is recorded in units of
Unpolluted, natural waters should have a BOD of
5 mg/L or less
Raw sewage may have BOD levels ranging from
150 – 300 mg/L
a measure of how well water can pass an electrical current. It is an indirect measure of the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, iron and aluminum.
It is an indirect measure of the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, iron and aluminum. The presence of these substances increases
the conductivity of a body of water.
................................like ..................................................do not conduct electricity very well, and thus have a ...................conductivity in water.
oil, alcohol, and sugar
Inorganic dissolved solids are essential ingredients for
Inorganic dissolved solids are essential ingredients for aquatic life. They
regulate the flow of water in and out of organisms’ cells and are building blocks of the molecules necessary for life.
A high concentration of dissolved solids, however, can cause
water balance problems for aquatic organisms and decrease dissolved oxygen levels
Temperature: Oxygen is more easily dissolved in
Flow: Oxygen concentrations vary with
the volume and velocity of water flowing in a stream.
Usually streams with ............................................................. are considered healthy streams.
high dissolved oxygen concentrations (greater than 8 mg/L for Ozark streams)
Usually streams with high dissolved oxygen concentrations (greater than 8 mg/L for Ozark streams) are considered healthy streams. They are able to support a greater
diversity of aquatic organisms
They are able to support a greater diversity of aquatic organisms. They are typified by
cold, clear water, with enough riffles to provide sufficient mixing of atmospheric oxygen into the water.
In streams that have been impacted by any of the above factors, summer is usually the
most crucial time for dissolved oxygen levels because stream flows tend to lessen and water temperatures tend to increase.
In general, DO levels less than .........are stressful to most aquatic organisms.
Most fish die at
Most fish die at 1-2 mg/L. However, fish can move away from
low DO areas