104 
EIGHTH REPORT. 
large number of towns. The water in its underground course naturally 
works towards the stream carrying with it the contamination which 
has been received from the bordering districts occupied by the villages. 
In spite of this fact water-works plants have in some cases been located 
on the river banks at about the worst place which could have been 
selected, the determining matter being the convenience of location rather 
than the safety. In such cases the water-works might generally have 
been located above the towns with a supply fully as great and with but 
little additional expense. With the heavy drafts made by pumping the 
-contributing district is enlarged and the danger increased; thus water 
which at the time of the installation of the wells was found by analysis 
to be uncontaminated may not long remain safe for use. 
It is generally true that flowing wells form a safe source of water 
supply, since their catchment areas are somewhat remote and the water 
must flow some distance underground to reach the wells. There are, 
hoAvever, instances in which flowing well districts located in valleys 
with rapid descent are supplied from the adjacent portions of a valley 
and its slopes. If such a catchment area is thickly inhabited there is 
more or less danger of contamination. 
Instances have also come to notice of carelessness in the conducting 
of water from flowing wells to the reservoirs or receiving wells, ordinary 
drain tile being laid at a slight depth, beneath, the surface to conduct the 
water into the receiving well. Where the drain tile is laid through a 
district bordered closely by cesspools and privies there are opportuni¬ 
ties for contamination, for the tile is naturally placed below the surface 
of the ground water table in order to prevent a loss of the flowing well 
water on the way to the receiving well, and the rapid current through 
the tile naturally draws in more or less water from the bordering dis¬ 
trict. 
WATER-WORKS. 
In the table of water-works supplies given below the population of 
the town as well as the source of supply and ownership of water-works 
has been given, but it should not be inferred that the number of actual 
users of public water supplies approximates that of the populations of 
the cities and villages, for this is the case in only a few of the cities 
outside of the metropolis, Detroit. On the basis of the number of taps 
reported it is estimated that in the cities with a population between 10,- 
000 and 100,000 only about two-thirds of the people are connected with 
the public supply, and in towns of less than 10,000 population one-half 
or less are thus connected. The probable actual users of public supplies 
are estimated to aggregate about 775,000, or 32 per cent of the entire 
population of the State in 1900 (2,420,982), while the aggregate popula¬ 
tion of towns and institutions provided with water-works reaches 1,- 
150,000, or nearly half the population of the State. Of the actual users 
of water-works supplies nearly 600,000, or about 24 per cent of the 
population of the State, are supplied from surface water, leaving less 
than 200,000 supplied from water-works drawing from wells. But of 
those not connected with the public supplies there are probably not more 
than 20,000 who depend upon surface water, including springs, while 
about 1,625,000, or two-thirds of the State’s inhabitants, depend upon 
private wells. 
