by the coliform count was also ten times the recommended standard or more
in some samples, and so were suspended particulates as measured by turbidity
‘
units.
Ten percent of the individual samples exceeded the standard for total or—
‘
gamic chemical compounds, but there were complaints by consumers of un—
pleasant taste and odor in water which was rated acceptable by the standard.
Total organics are measured by ltering a sample of water through activated
carbon and then using chloroform to extract the organics which have been
absorbed on the carbon. However, not all the organics are absorbed onto the
'
carbon and, of those absorbed, not all are extracted in the chloroform. There
‘
may therefore have been organics present which were not measured. PHS investigators also suggested that the unpleasant taste and odor might be caused
‘
by the interaction of the chlorine used in water purication with organic
chemicals, even when the latter are present only in “acceptable” amounts.
Contaminants in open surface water (rather than in community water sys—
tems) were investigated at several hundred stations throughout the country
by the US. Geological Survey in October 1970 [4]. Some stations were downstream from industries, some were on streams in undeveloped areas, and some
,
were at the sources of drinking water supplies. The investigators tested for arÉ
senic, cadmium, chromium, cobalt, lead, mercury, and zinc, and found all
these heavy metals widely distributed in US. waterways in low concentra—
tions and sometimes in amounts exceeding PHS drinking water standards. In
Î
two percent of the samples (from both undeveloped and urban areas), arsenic
.
exceeded the limit of 0.05 mg/l; four percent of the samples, mainly near ur—
ban areas, were in excess of the limit for cadmium; and 63 percent of the sam—
ples contained 0.001—0.05 mg/l of lead, and a few exceeded the 0.05 limit.
The recommended limit for zinc—5 mg/l—was also exceeded in a few cases.
The relative importance of natural and industrial sources was not clear.
A more revealing picture of industrial pollution developed when the EPA
investigated the lower Mississippi River [5]. In a 256-mile stretch of the river
from north of Baton Rouge to south of New Orleans, a large concentration of
modern chemical and petroleum rening works, including the largest petm—
‘
leum renery in the United States, has developed. The Mississippi serves as
;
both a disposal site for industrial wastes and the source of raw domestic water
for 40 utities servicing about 1.5 million people.
Masses of dead sh, apparently killed by chernicals, tainted sh esh, and
.
drinking water with chemical odors and tastes prompted state ofcials" to
request the EPA’S investigation of this area, which took place in 1969—1970.
‘
Contamination of drinking water was found and was traced to the discharge
of huge amounts of pollutants from 60 major industries on the lower Mis—
sissippi. On a single day, each of 42 plants discharged at least one heavy
metal to the river in amounts ranging upward from ve pounds. The day’s total discharges included 3700 pounds of lead from one plant, 71 pounds of cad—
mium from another, 396 pounds of copper from another, and 200 pounds of
,
chromium from still another [6].
Each of these metals has well—known toxic properties. In the case of lead—
’
150 Drinking Water
in some samples, and so were suspended particulates as measured by turbidity
‘
units.
Ten percent of the individual samples exceeded the standard for total or—
‘
gamic chemical compounds, but there were complaints by consumers of un—
pleasant taste and odor in water which was rated acceptable by the standard.
Total organics are measured by ltering a sample of water through activated
carbon and then using chloroform to extract the organics which have been
absorbed on the carbon. However, not all the organics are absorbed onto the
'
carbon and, of those absorbed, not all are extracted in the chloroform. There
‘
may therefore have been organics present which were not measured. PHS investigators also suggested that the unpleasant taste and odor might be caused
‘
by the interaction of the chlorine used in water purication with organic
chemicals, even when the latter are present only in “acceptable” amounts.
Contaminants in open surface water (rather than in community water sys—
tems) were investigated at several hundred stations throughout the country
by the US. Geological Survey in October 1970 [4]. Some stations were downstream from industries, some were on streams in undeveloped areas, and some
,
were at the sources of drinking water supplies. The investigators tested for arÉ
senic, cadmium, chromium, cobalt, lead, mercury, and zinc, and found all
these heavy metals widely distributed in US. waterways in low concentra—
tions and sometimes in amounts exceeding PHS drinking water standards. In
Î
two percent of the samples (from both undeveloped and urban areas), arsenic
.
exceeded the limit of 0.05 mg/l; four percent of the samples, mainly near ur—
ban areas, were in excess of the limit for cadmium; and 63 percent of the sam—
ples contained 0.001—0.05 mg/l of lead, and a few exceeded the 0.05 limit.
The recommended limit for zinc—5 mg/l—was also exceeded in a few cases.
The relative importance of natural and industrial sources was not clear.
A more revealing picture of industrial pollution developed when the EPA
investigated the lower Mississippi River [5]. In a 256-mile stretch of the river
from north of Baton Rouge to south of New Orleans, a large concentration of
modern chemical and petroleum rening works, including the largest petm—
‘
leum renery in the United States, has developed. The Mississippi serves as
;
both a disposal site for industrial wastes and the source of raw domestic water
for 40 utities servicing about 1.5 million people.
Masses of dead sh, apparently killed by chernicals, tainted sh esh, and
.
drinking water with chemical odors and tastes prompted state ofcials" to
request the EPA’S investigation of this area, which took place in 1969—1970.
‘
Contamination of drinking water was found and was traced to the discharge
of huge amounts of pollutants from 60 major industries on the lower Mis—
sissippi. On a single day, each of 42 plants discharged at least one heavy
metal to the river in amounts ranging upward from ve pounds. The day’s total discharges included 3700 pounds of lead from one plant, 71 pounds of cad—
mium from another, 396 pounds of copper from another, and 200 pounds of
,
chromium from still another [6].
Each of these metals has well—known toxic properties. In the case of lead—
’
150 Drinking Water