Vol. 15—1961 - NorthEastern Weed Science Society

473.
time prior to the water's ultimate entry into the reservoir
and thus gave time for disipation of the odors and tastes
from the Silvex carrier. Third, short circuiting of the .
incoming stream was prevented since there was no outlet.
Samples were collected prior to treatment for analysis
for temperature, odor, color, turbidity and pH. The lake was
divided into two sections and treatment was made by an experienoed
applicator. A mixture of Silvex and water was sprayed
over the surface of the lake from a boom behind an outboard
motor barge. It was introduced at a rate to give a concentration
of 2 p.p.m. active material in the area covered.
Samples were collected at the time of application, one
day; 1, 2, 3 and 4 weeks after application, to observe any
change in the physical characteristics of the water; that is
color, turbidity, and odors. The State Department of Health
collected samples for phenol determination and samples were
collected to see if there would be a bacteriological build-up.
The average color, before treatment, was 24 p.p.m. Four
hours after treatment this had dropped to 14, then stabilized
near 20 for the remainder of the samples collected. All samples
were taken from apprOXimately one foot beneath the surface.
The average turbidity, before treatment, was 3 p.p.m.,
and this rose to a high of 6 one day after the application
and returned to 3 seven days later.
The threshhold odor of the heated water was ~ before
treatment and it had an earthy musty characteristic. During
treatment this rose to a high of 60, With a kerosene characteristic
due to the carrier. This fell to 25 one day later
and further dropped to 8 with a musty kerosene odor predominate
after one week. Three weeks later the odor was down
to 3 and had a musty earthy or vegetable musty characteristic.
The pH was 9.1, before treatment, and dropped to 6.8
after treatment, which is understandable since an acid is beihg
added to the water. The physical results were much the
sama for the second half, which was treated one week later.
Aftar the second treatment it was noticed that a number of
very large and very small fish were dying. Samples of the
fish were frozen and sent to a laboratory to try to determine
whether the cause of death was due to oxygen depletion or
chemical poisoning.
One of the primary concerns of the water purveyor is the
introduction of any phenol compound into his supply since
phenol concentrations as low as 3 parts per billion can eause