WATERWORKS LABORATORIES. 
JACK J. HINMAN, JR. 
The material which I have put into this paper is a part of 
the data which I hav^ been gathering for an article on the con- 
trol of waterworks plants by laboratory methods. The audi- 
ence which I am considering in the preparation of that paper is 
one which is interested specifically in the problems and tech- 
nique of the waterworks plant. Numerical results of operation, 
and quantity weights are naturally of greater interest to them 
than they are to you. Indeed, the tabulations and deductions 
which I have to offer to you today are of a rather special in- 
terest. 
My hope is that my data on the laboratories themselves may 
not prove uninteresting to you, although they are based almost 
entirely upon the figures upon a single chart. 
To begin with, I sent out a very comprehensive questionnaire 
to every town in the United States and Canada that had a pop- 
ulation of 25,000 or more at the time of the 1910 census. A 
few additional questionnaires were sent to a number of other 
towns in adjoining states. These towns were selected on ac- 
count of the method of water purification employed. 
My percentage of replies has been excellent. I have data on 
an average daily pumpage of more than 3 ; 000 million gallons 
of water of which more than 2,800 million gallons, supplying 
a population of nearly 17 million people, on the basis of the 
1910 report, is protected by laboratories directly under the con- 
trol of the waterworks officials or their superior officers. Plants 
which are more or less completely controlled by contract chemists 
or special arrangements with local concerns or institutions are, 
for the time being, omitted. 
In the control of the 90 plants which supply the 2,800 million 
gallons of water daily, 195 laboratory workers are employed. 
Of these, 91 have the title of chemist or assistant chemist. Many 
of the others have the title superintendent of filtration or lab- 
oratory director, and so on. Some of these men I know have 
had chemical training. Some are engineers who have picked 
up the rudiments of water examination and carry on such de- 
terminations as are necessary for their plants. The preponder- 
ance of one-man laboratories is significant and the variety of 
