What is turbidity?
It is the measurement of lack of water clarity that is measured in NTU
or JTU.
What factors influence the turbidity of water?
1. Turbidity is the result of suspended solids in the water that range
from clay, silt, and plankton, to industrial wastes and sewage. The
lower the turbidity, the clearer the water is.
2. High turbidity may be caused by soil erosion, waste discharge, urban
runoff, flooding, dredging operations, channelization, increased flow
rates, algae growth, or even too many bottom-feeding fish (such as carp)
that stir up bottom sediments.
What is the optimal amount of turbidity of water for most aquatic
plants and animals?
1. A normal range for a turbidity of a river has not been established.
2. Turbidity of drinking water can range from 0.5-1.0 NTU, but should
never exceed 1.0 NTU.
3. Turbidity that exceeds 5.0 NTU can be easily detected.
4. A turbidity of 0-10 JTU is considered normal.
What factors are affected by the turbidity of your watershed?
1. Turbid water’s particles absorb the sun’s rays, which cause
the water temperature to increase and dissolved oxygen to decrease.
This may negatively affect the quality of aquatic life.
2. If the water is too turbid, it loses the ability to support a wide
variety of aquatic plants and animals.
3. Suspended solids reduce the amount of light that can pass through
the water. As less light penetrates the water, photosynthesis slows,
releasing less oxygen into the water. If light is blocked to bottom-dwelling
plants, they will cease to produce oxygen and will eventually die. As
they decompose, bacteria will use up more oxygen from the water. This
will decrease the amount of dissolved oxygen concentration in the water
and may cause stress or even death to aquatic organisms that need high
amount of oxygen to survive.
4. Suspended solids can clog and damage the fish’s gills.
5. Turbid water can interfere with the ability for fish to find food.
6. Suspended solids can prevent proper egg and larval development. As
particles of silt, clay, and other organic materials settle to the bottom,
they can suffocate newly hatched larvae.
7. Settling sediments can fill in the spaces between rocks, which could
have been used to provide homes for aquatic organisms.
