=+=====+=====+=====+=====+=====+=====+=====+=====

[Footnote 1: Filtered water section. Allegheny District not
included.]

Attention has repeatedly been called to the fact that the relatively
high typhoid death rate in Washington, since the filter plant was
installed, was a possible indication that the filters were
inefficient. It is true that there has not been the marked reduction
in the typhoid death rate in Washington, following the installation
of the water filtration works, that has been observed in other
cities in America. For the six years prior to the date on which
filtered water was supplied to the citizens of Washington, the
average typhoid fever death rate was 59 per 100,000 population, as
against 37 per 100,000 for the five years following, a reduction of
37 per cent. At Albany, N. Y., where the first modern slow sand
filter was built in 1899, the typhoid death rate has been reduced by
75 per cent. At Cincinnati, Ohio, the average death rate from
typhoid ranged around 50 per 100,000 for years, but since the
installation of the filtration plant it has been reduced to a point
which places that city, with respect to freedom from typhoid fever,
at the head of all the large cities in America; in 1910 the death
rate from typhoid in Cincinnati was 6 per 100,000. Similarly, at
Columbus, Ohio, where the typhoid death rate before the installation
of the filtration plant in 1906 was even higher than at Cincinnati,
it was reduced to less than 13 per 100,000 in 1910, whereas, for the
previous five years, it was 61 per 100,000. Philadelphia, before the
installation of the filtration works, had a typhoid death rate of 60
or more per 100,000, and in 1910 the death rate from this disease
was 17. Pittsburg, at least that part of it now supplied with
filtered water, for years had a typhoid death rate of more than 130
per 100,000, but the present rate is about 12 per 100,000.

~Table 25--Average Monthly Results for the
Period, 1905-1910.~

Columns:
A - Period of sedimentation in days.
B - Turbidity in parts per million.
C - Bacteria per cubic centimeter.
============+=====+=====+=======+=====================
| | | |~Percentage Removed~
Reservoirs.| A | B | C |----------+----------
| | | | Turbidity| Bacteria
------------+-----+-----+-------+----------+----------
River | ... | 106 | 6,400 | ...