The evening times., 1897-11-20
POLLUTION OF THE POTOMAC.
Nr. Arthur p. Davis Paper Before
the Geog raphic Society.

the GeOg raphic Society.
The pollution of the Potomac River was
discussed last night at Columbian Univer'
SIT. befoIe the National Geographic So
ciety by Pref. Arthur Davis, OF the Gen
logical survey, and DR.. E. X. sprasue,
OF the Marine Hospital Service. There
was a large attendance OF members and
guests OF the society. At a meeting held
before the stated address, Col. H.. +.
Blount in the chair, some amendments
tn the bylaws were adopted, one OF the
imIt rtant things being that mefnier
who llaG paid $50 In dues could beaoiie
q Hfs member for an additional $25.
Prof. Davis paper was read by Mr..
F H. Newell. 1t states simply the sources
oI contamination of the river above wasis
iDgton. The worst conditions exist in the
vicinity of Cumberland, where the waters
are particuia riy foul from the sewage Of
that city, mingled with the water from
IniEes and waste from manufacturing es-
Ia ablishments. A short distance below CuDr
ber.and is a dam hacking up the water
for several miles, and forming d pool in
which all of the filth of this relatively
thicklv populated region collects.
IL Shenandoah Valley the streams are
rea tively pure. The towns, however,
discharge a considerable quantity OF sew
age into the stream.
The water supply for Washington is OBJ
taiued 10y al aGueduct heading above Great
Falls, and in times Of extreme low water,
takes In from 6 to 8 per cent OF the entire
flow Of the river AT other stages, the
percentage becomes far less. The sewn ge
from the vicinity Of Cumberland and other
towns " Ill require from two To four days, or
even more. to reach the Washington aqle-
duct, and by that time it is very dilute ,and
probably most of the organic matte has
disappeared, In the case Of pathogeuic
germs, however, there is reasonable cause
fc- doubt as to whether this short exposure
to light and air will modify or Gcstr,.y
them. II such organisms are hi aaitrally
dumped into the water from various set
Elements along the banks Of the stream, It
would seem highly probable that they must
IN part enter the Washington aqceduct
within sucn d short time that the virn!ence
is not impaired. The failure to finl such
organisms caunOt be regarded AS con-
elusive evidence OF their non-ex:stencc, as
tn. waller saiapies vary SO greatly tr"m
hour t. hour, or when taken from different
localities.
I,r. Sprague gave 4 history OF the hac-
THEOLOGICAL work OF the Marine Hospital
Service Iuring the past six years. Since
July l of this year semi weekly exam
nations of the Potomac water have been
made. The number of organisms in the
wctcr vary from l so to 4 teaspoonful TO
90, 900 to a teaspoOnful, with an averaga II
something over 1000 to a teasponnful
Since August l they found intestinal bac-
terra in every sample, with possibly one
exception. In addition to the samples
tai:"n from tire tap, fifty-five samples
collected at various points up the river 10y
representatives OF the Geological Survey
hav,. been exaIrined.
The dangers to be apprehended from
pbIlIted water ATE typhoid fever. iItestina.
diseases and, possibly, tuberculosis. N
1883 the dCatn-rate from typhoid f."er
la til District was 3.G per cent per lU,puJ,
and in Sg6 was S-3 per cent. In 1880
aud 1891 the rate was SO and S.5 per
cen. per 10000, respectively The relation
hetw cen the endemic at Cumberland md
this increase WAS something more than n
coincidence. 1t was the logical result From
drinking water contaminated with ty-
phoid.
As to remedies, he said that filtration
through properly-constructed filter beds mt
the plmping station is the only practical
means OF purifying a public water supply.
Experience proves that filtration removes
frcm 80 t. 9S per cent of the hacte:ia,
ami the death-rate from water-borne dis
eases is correspondingly reduced.
Both lectures were admirably Illus
trated.