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VALUE OF LABORATORY CONTROL OF OPERATION OF
WATER PURIFICATION PLANTS'
W. W. DeBerard: Samples taken from twelve different points
over the system of the Denver Union Water Company last No-
vember and analyzed in four different laboratories indicated a re-
markable uniformity of result, considering the fact that each labora-
tory used its own particular routine. This routine was essentially
the same throughout except for the mediimi used in the fermenta-
tion tubes for the B. coli tests. One used lactose bile; another,
fresh ox bile; another, "bacto-bile" and the fourth, dried ox gall.
The laboratories collaborating were those of William C. Mitchell,
city bacteriologist, Denver; Dr. John B. Ekeley, state chemist.
University of Colorado, Boulder; H. I. DeBerard, chemist, Denver
Union Water Company, and Prof. W. G. Sackett, bacteriologist,
Colorado Experiment Station, Ft. Collins.
Some of the figures are as follows: From the infiltration galleries
at Mississippi Street the average of five counts on gelatin at 20°C.,
after forty-eight hours was 11, with a maximum of 16 and minimum
of 6. Raw samples taken from Marston Lake averaged 520, with
a maximum and a minimum of 750 and 300 respectively. Similar
figures for the effluent of the Platte Canon slow sand filters, treated,
were 49, 75 and 12. A mixed supply taken from the tap in the city
chemical laboratory gave an average of 42, maximum of 69 and
minimum of 21.
Typical results on agar at 37°C. for the Platte River, raw, are as
follows: Average, 52; maximum, 73 and minimum, 17. For the
Willard rapid filter effluent, treated, the average was 3, maximum
5, and minimmn 2. From a drinking fountain at the comer of
First Avenue and Broadway the average was 8, maximum 17 and
minimmn 3.
Equally close imiformity extended to the samples examined for
B. coU per 100 cc. From the Mississippi Street galleries, Marston
Lake treated, a slow sand filter effluent at Wynetka, Platte Canon
*A discussion at a meeting of the Illinois Section at Urbana on March
13, 1917.
372
VALUE OF LABORATORY CONTROL 373
infiltration galleries, Willard rapid filters, a drinking fountain and
the Cherry Creek infiltration galleries, no coli were found by tha
analysts.
0. M. Smith: Laboratories in small plants are often placed in
unoccupied corners somewhere in the filter or boiler room. Here
they are neglected and gradually become an eyesore instead of
an inspiration to the superintendent and the workman. The tend-
ency of recent years has been to place more importance on the lab-
oratory. Superintendents are finding that a well equipped and well
appearing laboratory is quite an asset and a valuable advertising
feature to the plant. The speaker understands that the American
Water Works & Electric Company finds the attractive, clean and
modern laboratory a paying investment and that it is its intention
while rebuilding the plant at East St. Louis, 111., to install one of
the finest plant laboratories in Illinois. If the laboratory is kept
clean, polished and has on exhibition interesting data and speci-
mens, such as graphs of turbidity, number of typhoid cases, effi-
ciencies, plates of bacteria, samples of water and sections of filters,
visitors and the public will become vitally interested in what
the company or department is endeavoring to do. An interested
and sympathetic public is one of the company's best assets.
On the question of records, the speaker has found that if data
such as pumpage, fuel duty, turbidity, coagulant, bacteria counts,
efficiencies, cost, etc., are daily plotted on cross-section paper in
such a manner as to be easily understood, the employes will become
more interested in what they are doing and more in sympathy with
the economical and efficient methods.
W. R. Gelston: It is obvious that some systematic laboratory
control should be applied to every water purification plant. The
fact that a purification plant is necessary to make the water satis-
factory is good evidence that the untreated supply is more or less
turbid, colored, and polluted. The purification of a water supply
adds very materially to the final cost to the department of deliver-
ing it to the consmner. We hear much in this enlightened age of
"Safety First" and "Efficiency." "Safety First" applied to puri-
fication plant operation should mean that the primary object of the
purification plant is to produce at all times an effluent safe for hu-
man consumption. "Efficiency" applied to plant operation means
374 DISCUSSION
economy. The man responsible for the operation of a water purifi-
cation plant should adopt a motto something like this: "Strive for
the best efficiency consistent with safety first."
Without laboratory control, the operator cannot be certain that
he is reducing his coagulant and sterilizing cost to the minimum
consistent with safety of effluent. Neither can he limit his labora-
tory control to a mere determination of the alkalinity, color, and
turbidity of his raw water and effluent. He must apply bacterial
control to determine whether the effluent is safe for human con-
sumption or not.
At Quincy, alkalinity and turbidity determinations were begun
many years ago. Bacterial control dates from 1909, when G. A.
Van Brunt was sent to Quincy by the State Water Survey to install
apparatus for bacterial tests and to instruct water works employees
in the standard methods applied to such tests. A small laboratory
was fitted up in one corner of the pumping station. Media were
purchased from the State Water Survey. About five samples each
of river, settled and filtered water were plated each week. This
limited control soon demonstrated the need of extensive improve-
ments. The improvements were not secured at once, but munici-
pal history does not reveal many instances of locking the stable
door before the horse is stolen.
A new purification plant was completed in August, 1914. A new
intake pipe was completed a year later, and a liquid chlorine ma-
chine was installed early in 1916. Quincy now secures its water
supply from a point in the Mississippi River which is not subject
to pollution by sewage. The water is coagulated, settled, filtered
and finally sterilized. That "Safety First" has been secured is
evident from the mortuary records kept by the board of health.
During 1916 there were two deaths from typhoid fever reported in
Quincy. One was a case imported from Camp Point for treatment
in a local hospital. The other was a young man who lived in a house
not supplied with city water. Quincy has a population of about
38,000. Two deaths per year are, therefore, equivalent to 5.3 per
100,000. The lowest previous record for Quincy was seven deaths
per year, or 19 per 100,000, and most of those deaths were probably
due to an imsafe water supply.
Since safety is now secured it might be suggested that bacterial
control is unnecessary or that the extent of such control might
properly be curtailed. Nevertheless, it has been kept up regu-
VALUE OF LABORATORY CONTROL 375
larly. Just how it has been kept up may be of intere t. The
speaker has always collected the samples, plated them, made the
counts, and recorded the results. Since the new filter plant was
erected he has also prepared all of the media used in the work.
The filter man has been pressed into service to make the alkalinity,
color and turbidity tests, and he also washes and steriUzes the glass -
ware and assists in the preparation of the media. It requires
about three and one-half hours of the speaker's time to prepare a
2-liter batch of agar which will last about five weeks, and about
three hours to prepare sufficient lactose broth to last five weeks.
It requires an average of about one and one-half hours to collect
samples, plate them, make the counts, and record them. Samples
are collected and plated about twenty times each month. Five
different samples of water are collected for each plating and duplicate
agar plates are run on each sample.
The filter man might be allowed to do all of this work, but the
laboratory control supplies the only reliable check upon the filter
man. The results of the bacterial tests, especially, show whether
he has been faithful in the performance of his duty or not. There-
fore, the speaker has always preferred to attend to the bacterial
work himself.
It is now generally known throughout the city that the superin-
tendent of the water department makes regular bacterial tests of the
water and the consumers realize that everything possible is being
done to insure a safe supply. He is sometimes called upon to test
samples of water from private wells and cisterns. Such tests are
always made without charge. Expert bacteriologists might pos-
sibly condemn this practice, but recently it was made to produce
three water services where only one grew before. It happened in
this way. A lady telephoned to inquire whether she could have a
cistern water tested. She stated that she had been getting her
water from a yard hydrant two doors away, but this hydrant was
frozen up and she did not want to use the cistern water at her house
until she knew that it was safe to drink it. The test was made
and it was found that one man owned three cottages, all of them
occupied by tenants. He laid a water service for one house and paid
a flat rate for water for one house only. He then instructed the
tenants in the other two houses to get water from the hydrant at
the first house if they preferred the city water to cistern water.
They preferred the city water and the landlord now pays for water
for three houses where he paid for only one before.
376 DISCUSSION
L. A. Fritze: The value of the laboratory in connection with the
operation of water piirification plants can best be judged by the
results that are being obtained. The restilts firmly estabUsh the fact
that every filtration plant, even to the smallest, requires a labora-
tory to maintain an intelligent idea of the quaUty of the effluent
produced. In the smaller plants, where the design and construction,
as a rule, are less perfect, it is quite important that routine labora-
tory tests be made in order to obtain a satisfactory degree of puri-
fication. The tests required are simple and in these small plants a
man with average intelligence can be trained to handle this work in
a very satisfactory manner. In the plants, however, where it is
possible to employ a chemist the operation will be placed upon a
better basis and the proper solutions of the many little problems that
arise will have a marked influence on conditions at the plant.
Aside from the daily routine analyses to determine the quality of
the raw and filtered water and the work required to maintain the
filters and other equipment in a satisfactory condition, there are
other things in which the laboraory can prove its value. In the
purchase of coal, chemicals and the large variety of material used
by a water department the laboratory can be of the utmost im-
portance. The handling of bad water complaints is another duty.
Sediment or color, odor or taste will produce their share of objectors
and if these consumers be referred to the laboratory for enhght-
enment, a non-technical explanation in a courteous manner will do a
great deal towards making the chronic kicker and others good
friends of the department.
In the municipally owned plants it is possible for the scope of the
work of the laboratory to be enlarged to include a nimiber of things.
With the work of the water department properly systematized valu-
able assistance can be given to other departments of the city. The
work of the health department requires the same care as that of the
water department. Establishing and maintaining the standards of
purity for the milk supply, ice cream and the various foods sold on
the open market present problems only to be solved by the labora-
tory. Making examinations of sputxmi, diphtheria cultures, urine
and other work, valuable to the physicians, will render the labora-
tory a valuable addition to the city. The street department can
be aided by tests of the various materials used, and, in fact, every-
thing purchased by the city, where an analysis is of use in deter-
mining value, the laboratory is a help.
VALUE OF LABORATORY CONTROL 377
A number of cities allow the matter of expense to stand in the
way of having a municipal laboratory. When the work accomplished
by a laboratory in a year's time is summed up, it is quite apparent
that the financial saving exceeds the expense and the health work
combined with the laboratory-control work for the filtration plant
have cost the city very little. In this connection the speaker wishes
to say that the valuable work carried on by the State Water Sur-
vey in checking the water supplies of the state and encouraging
cities to establish municipal laboratories should be heartily endorsed.