Environmental Engineering Reference
In-Depth Information
to be $96.2 million (1993 U.S. dollars), with about $31.7 million in medical
expenses and about $64.6 million in productivity losses.
49
Between 1946 and 1980, a total of 672 waterborne disease outbreaks were
reported, with 150,475 cases. Contaminated untreated groundwater accounted
for 35.3 percent of the 672 outbreaks, inadequate or interrupted treatment for
27.2 percent, distribution or network problems for 20.8 percent, contaminated
untreated surface water for 8.3 percent, and miscellaneous for 8.3 percent.
Forty-four percent of the outbreaks involved noncommunity water systems and
accounted for 19 percent of the cases.
50
Weibel et al.
51
studied the incidence of waterborne disease in the United States
from 1946 to 1960. They reported 22 outbreaks (10 percent) with 826 cases due
to use of untreated surface waters; 95 outbreaks (42 percent) with 8,811 cases
due to untreated groundwaters; 3 outbreaks (1 percent) with 189 cases due to
contamination of reservoirs or cisterns; 35 outbreaks (15 percent) with 10,770
cases due to inadequate control of treatment; 38 outbreaks (17 percent) with
3,344 cases due to contamination of distribution system; 7 outbreaks (3 percent)
with 1,194 cases due to contamination of collection or conduit system; and 28
outbreaks (12 percent) with 850 cases due to miscellaneous causes, representing
a total of 228 outbreaks with 25,984 cases.
Weibel et al.
51
reported the greatest number of outbreaks and cases in commu-
nities of 10,000 population or less. Wolman and Gorman stated that the greatest
number of waterborne diseases occurred among population groups of 1,000 and
under and among groups from 1,000 to 5,000 — that is, predominantly in the rural
communities.
52
Between 1971 and 1978, 58 percent of the outbreaks occurred
at small, noncommunity water systems. The need for emphasis on water supply
control and sewage treatment at small existing and new communities, as well
as at institutions, resorts, and rural places, is apparent and was again confirmed
in the 1970 PHS study,
53
a 1978 summary,
54
and others.
50
From 1971 to 1982,
a total of 399 waterborne outbreaks with 86,050 cases of illness were reported
to the U.S. Public Health Service. Forty percent of the outbreaks occurred at
community water systems, 48 percent at noncommunity systems, and 12 percent
at individual systems. Thirty-one percent involved groundwater systems serving
motels, hotels, camps, parks, resorts, restaurants, country clubs, schools, day care
centers, churches, factories, offices, and stores. Thirty-one percent of the total
waterborne outbreaks were caused by use of contaminated untreated ground-
water (wells and springs); 20 percent by inadequate or interrupted disinfection
of groundwater (wells and springs); 16 percent by distribution system deficien-
cies (cross-connection, storage facilities, and contamination of mains and through
household plumbing); 14 percent by inadequate or interrupted disinfection of sur-
face water; 8 percent by use of contaminated untreated surface water; 4 percent
by inadequate filtration, pretreatment, or chemical feed; and 7 percent by mis-
cellaneous deficiencies.
55
In another analysis of 484 waterborne outbreaks with
110,359 cases between 1971 and 1985, the agent was bacterial in 59, parasitic
in 90, viral in 40, chemical in 51, and acute gastrointestinal in 244. Community
systems, noncommunity systems, and individual systems experienced 209, 217,
