or lake, creating conditions inhibitory to desirable fish and aquatic organisms.
Depending upon the orientation, it could also contaminate the drinking water supply.
Significant pollution control activities arose in the early 1900s with disinfection of
drinking water by chlorination, coagulation and filtering of drinking water, and
treatment of wastes to remove the organic load before discharge. Thus began the
era of the sanitary engineer.
Although waste treatment greatly reduced disease transmission, the removal of
the organic materials did not reduce the oxygen demand as expected. It was observed
that inorganic nutrients, particularly nitrogen and phosphorus, were little reduced in
the waste treatment process. These nutrients were available to stimulate aquatic
growths, especially photosynthetic algae, which is new organic material. When these
algae die, they decompose and exert an oxygen demand on the receiving body of
water, not unlike the organic load that was so diligently removed by the treatment
system. Although this was not a public health hazard, it did interfere with biological
life in the receiving waters, including eliminating certain fish. As more and more
interrelationships between waste treatment and its impact on the receiving water
were observed, we had the development of the so-called environmental engineer.
Despite our concerted efforts to treat wastes to a degree that the effluent will have
no deleterious impact on the environment, we are continually developing and finding
new substances that are or can be deleterious. These include toxic and hazardous
materials frequently used in manufacturing processes, persistent or refractory substances that may have been developed for this very purpose (viz., PCBs, various
insecticides and herbicides), hormones from bioengineering processes, endocrine
disruptors, and antibiotics from constant use and overuse in controlling diseases and
infections. In addition to direct discharges of treated wastes, there are indirect
discharges such as leaching from landfills, leakage from underground storage
tanks, and condensation of volatile substances in the atmosphere during rainfall.
Oxides of nitrogen and sulfur from combustion produce acid rain that may be carried
great distances from their source, resulting in lakes of acidity high enough to
interfere directly with aquatic life, particularly fish, or to dissolve inhibitory minerals
from the surrounding rocks, with similar effects. Each problem requires its own
solution. Thus it can be seen that as mankind progresses, pollution problems seem to
increase.
Whereas we place greatest emphasis on the effects of pollution on humans, it
must be realized that other parts of the environment, including both plants and
animals, may also be impacted. Frequently, these may also indirectly impact
humans. A commonly used example of this is the benefit of DDT in controlling
insect-borne diseases. After considerable use and study, it was found that the DDT
created thin shells in the eggs of birds, thereby interfering with their reproduction.
Particularly, birds of prey were reduced, resulting in an increased population of
rodents and other small animals with the subsequent destruction of many crops. The
chain of impact is often diverse.
Although there are sources of pollution from the air and the soil, this chapter will
be restricted to the study of water bodies. This is not to lessen the importance of these
6 Basic Hydrology, Water Resources, and DAF Boat Plant for Lake Restoration
233
Depending upon the orientation, it could also contaminate the drinking water supply.
Significant pollution control activities arose in the early 1900s with disinfection of
drinking water by chlorination, coagulation and filtering of drinking water, and
treatment of wastes to remove the organic load before discharge. Thus began the
era of the sanitary engineer.
Although waste treatment greatly reduced disease transmission, the removal of
the organic materials did not reduce the oxygen demand as expected. It was observed
that inorganic nutrients, particularly nitrogen and phosphorus, were little reduced in
the waste treatment process. These nutrients were available to stimulate aquatic
growths, especially photosynthetic algae, which is new organic material. When these
algae die, they decompose and exert an oxygen demand on the receiving body of
water, not unlike the organic load that was so diligently removed by the treatment
system. Although this was not a public health hazard, it did interfere with biological
life in the receiving waters, including eliminating certain fish. As more and more
interrelationships between waste treatment and its impact on the receiving water
were observed, we had the development of the so-called environmental engineer.
Despite our concerted efforts to treat wastes to a degree that the effluent will have
no deleterious impact on the environment, we are continually developing and finding
new substances that are or can be deleterious. These include toxic and hazardous
materials frequently used in manufacturing processes, persistent or refractory substances that may have been developed for this very purpose (viz., PCBs, various
insecticides and herbicides), hormones from bioengineering processes, endocrine
disruptors, and antibiotics from constant use and overuse in controlling diseases and
infections. In addition to direct discharges of treated wastes, there are indirect
discharges such as leaching from landfills, leakage from underground storage
tanks, and condensation of volatile substances in the atmosphere during rainfall.
Oxides of nitrogen and sulfur from combustion produce acid rain that may be carried
great distances from their source, resulting in lakes of acidity high enough to
interfere directly with aquatic life, particularly fish, or to dissolve inhibitory minerals
from the surrounding rocks, with similar effects. Each problem requires its own
solution. Thus it can be seen that as mankind progresses, pollution problems seem to
increase.
Whereas we place greatest emphasis on the effects of pollution on humans, it
must be realized that other parts of the environment, including both plants and
animals, may also be impacted. Frequently, these may also indirectly impact
humans. A commonly used example of this is the benefit of DDT in controlling
insect-borne diseases. After considerable use and study, it was found that the DDT
created thin shells in the eggs of birds, thereby interfering with their reproduction.
Particularly, birds of prey were reduced, resulting in an increased population of
rodents and other small animals with the subsequent destruction of many crops. The
chain of impact is often diverse.
Although there are sources of pollution from the air and the soil, this chapter will
be restricted to the study of water bodies. This is not to lessen the importance of these
6 Basic Hydrology, Water Resources, and DAF Boat Plant for Lake Restoration
233