Page 302 - Moving the Earth_ The Workbook of Excavation

PONDS AND EARTH DAMS

6.38 THE WORK

FIGURE 6.25 Gathering mud near ramp.

FIGURE 6.26 Dozer-dragline team.

Water Plants. Vegetation in ponds is of many kinds, few of which are desirable.
The blue-green filamentous (stringy) algae, which grow in surface masses that may have con-
siderable depth, are often a major nuisance. They may be dense enough to make swimming and
even boating impossible. These algae grow vigorously (bloom) in the spring, and at irregular
intervals throughout the warm months.
In large lakes, these plants can flourish only if the water is overenriched by drainage carrying
sewage, detergent, fertilizer, or other nutrients. In small and shallow ponds, however, they often
grow very well without such assistance.
Fortunately, such algae are very susceptible to poisoning by tiny amounts of copper sulfate,
and die within a few days of contact with it. This chemical may be obtained in the form of coarse
blue crystals from large hardware stores, or from dealers in commercial or agricultural chemicals.
The easiest way to apply it is to put in a burlap or other loose-weave bag, then tow it behind a
boat, or pull it by hand while wading or swimming.