year
ending September 30th, 1909, the cost of operation had increased to
$7.63 per million gallons, and the total cost of filtration to
$15.92 per million gallons, or approximately 50% in three years.

~Table 27--Results of Bacteriological Analyses of Samples of
Water at Peekskill, N. Y., Before and After Filtration.~

~Bacteria per cubic centimeter.~
==============+=======+=======+========+========+========+========+========
| Raw | Clear |Effluent|Effluent|Effluent|Effluent| Tap in
Date. | water.| reser-| No. 1. | No. 2. | No. 3. | No. 4. | city.
| | voir.| | | | |
--------------+-------+-------+--------+--------+--------+--------+--------
1909.
--------------+-------+-------+--------+--------+--------+--------+--------
December 29th | 190 | 100 | ... | ... | ... | ... | ...
--------------+-------+-------+--------+--------+--------+--------+--------
1910.
--------------+-------+-------+--------+--------+--------+--------+--------
February 15th | 135 | 10 | 10 | 30 | 20 | ... | 265
March 31st | 225 | 50 | 25 | 45 | 60 | ... | 35
May 18th | 300 | 29 | 22 | 26 | 35 | 43 | 36
July 6th | 300 | 44 | 9 | 3 | 41 | 10 | 31
August 16th | 60 | 5 | 0 | 4 | 1 | 13 | 15
October 3d | 550 | 14 | 12 | 14 | 38 | ... | ...
November 21st | 315 | 22 | 26 | 17 | 6 | ... | ...
--------------+-------+-------+--------+--------+--------+--------+--------
1911.
--------------+-------+-------+--------+--------+--------+--------+--------
January 25th | 415 | 7 | 8 | 4 | 6 | ... | 7
--------------+-------+-------+--------+--------+--------+--------+--------
Average | 277 | 30 | 14 | 16 | 26 | 22 | 65
==============+=======+=======+========+========+========+========+========

~Table 17~--(_Continued._)
~Tests for~ _B. Coli._
==================+======================
|~Percentage of Samples
Quantity of water |Containing~ _B. Coli_.
tested. +--------+-------------
| Raw. | Filtered.
------------------+--------+-------------
0.1 cu. cm. | 0