Title: Reclamation of Water From Sewage
Full Citation
Permanent Link: http://ufdc.ufl.edu/WL00002910/00001
 Material Information
Title: Reclamation of Water From Sewage
Physical Description: Book
Language: English
Publisher: Fla Engineering and Industrial Experiment Station
Spatial Coverage: North America -- United States of America -- Florida
Abstract: Richard Hamann's Collection - Reclamation of Water From Sewage
General Note: Box 12, Folder 1 ( Materials and Reports on Florida's Water Resources - 1945 - 1957 ), Item 24
Funding: Digitized by the Legal Technology Institute in the Levin College of Law at the University of Florida.
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Bibliographic ID: WL00002910
Volume ID: VID00001
Source Institution: Levin College of Law, University of Florida
Holding Location: Levin College of Law, University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Full Text

Reclamation of Water from Sewage


Most sewage is about 99.9 per cent pure water.
\Vell-treated sewage may have a purity exceeding 99.99
per cent. Most industries would consider themselves
Fortunate to be able to start off with a raw product
approaching such a degree of refinement. For the most
part, however, this country has been fortunate in hav-
ing bountiful sources of good water requiring only
token treatment in many cases. Of all the states, Flor-
ida has been one of the most fortunate in this regard.
For this reason, the reclamation of water from sewage
a new development, relatively, in Florida. But it
is not new in some other places.
In many western communities, the utilization of
sewage effluents for irrigation purposes has been prac-
ticed for many years. In a 1939 publication of the U.S.
Department of Agriculture, a list was given of 113
communities where such utilization was made in the
western states.1 The primary reason for such a wide-
spread use of sewage at that time was because the
supply of water for irrigation was limited. It is even
more limited today and it will become increasingly so
in the future because of greatly increasing demands
for water in large quantities.
Water has become so limited in many areas that
some industries are finding it profitable to use treated
sewage instead of water in various manufacturing pro-
cesses; in other words, they are reclaiming water from
sewage in the truest sense of the word. And the need
for so doing has proven a blessing in disguise in a
number of instances. Examples of this have been
covered in the literature so exhaustively that there is
little need of repeating them here. The magnitude of
the problem may be illustrated, however, by the fact
that the Bethlehem Steel Company at Sparrows Point,
Maryland, has undertaken capital expenditures in ex-
cess of $2,000,000 for the development of a water sup-
ply with the treated effluent of the Back River Sewage
Treatment Works of Baltimore City2. This project
is considered an epochal milepost in the conservation
of water supplies, and the actual operation costs
chargeable to sewage reclamation as a raw water supply
is only about $10 per million gallons, which is equiva-
lent to $3.26 per acre-foot.3 In general, the cost of
reclaiming water from sewage is fairly reasonable. It
is much less than the cost of desalting sea water, but

*Professor of Civil Engineering, University of Florida.

in many instances it is higher than the cost of obtain-
ing fresh water from other sources and, of course, the
relative costs should always be considered in develop-
ing water supplies from any source.

Reclamation at Campus Plant
A good example of how sewage may be reclaimed
for useful purposes is illustrated at the University of
Florida which has an unusually well-operated sewage
treatment plant. The plant is supervised by George
H. Lohmeyer, a graduate student who furnished most
of the basic information upon which the following
comments are based.
As originally constructed in 1947, the plant con-
sisted of primary and secondary treatment units with
a design capacity of 700,000 gallons per day. Before
secondary settling and chlorination, half of the sewage
is normally subjected to biological treatment in a
standard-rate trickling filter, and the remaining half
in a high-rate filter. When the plant was first placed
into operation late in 1947, the effluent from the chlo-
rine contact chamber was discharged into a drainage
ditch where dilution was practically negligible. In
1950 a lagoon or oxidation pond providing for a
24-hour detention was placed in operation between
the contact chamber and the drainage ditch. The la-
goon was built primarily for experimental purposes
and for instructing students specializing in sanitary
The following is a summary of typical results which
were obtained from plant operation data during the
spring semester starting with February 1954, a period
of few fluctuations in volume and strength of the raw
While treating an average of 580,000 gallons per
day, the 5-day B.O.D. was reduced from 201 parts per
million in the raw sewage to 11 p.p.m. at the inlet
to the oxidation pond. An average chlorine residual
slightly over 1.0 p.p.m. was maintained in the plant
effluent. While such a residual would be considered
high by ordinary standards, it is reasonable here be-
cause of the porous limestone formations underlying
the Gainesville area. The chlorine residual is quickly
expended in the oxidation pond.
For the period indicated, the B.O.D. reduction
through the lagoon averaged 32 per cent; while the
dissolved oxygen concentration in the lagoon averaged
4.4 p.p.m., and the nitrate concentration in the plant

___ I __~

effluent entering the pond averaged slightly over
20 p.p.m. (During the summer months when the
flow rates are lower and temperatures are higher,
these results are further improved.)
Since early 1952, the highly nitrified effluent has
been used for campus lawn sprinkling in areas ad-
jacent to the plant site. The University Grounds De-
partment has also found the plant effluent valuable
for irrigation purposes, in the cultivation of flowers
and in growing shrubbery and turf for campus beau-
The quantity of effluent used for irrigation has
naturally varied with the amount of rainfall. Pumpage
from the lagoon is heaviest during periods of little or
no rain. When low sewage flows occur simultaneously
with such pumpage, no liquid reaches the ditch which
normally receives the sewage. During the month of
August 1953, however, when the total rainfall was
12.78 inches, only 1.0 million gallons were pumped
from the sewage lagoon. In June 1954, when 3.38
inches of rain fell, 5.04 million gallons were pumped.
The latter represented 36 per cent of the total sewage
flow for the month, and it does not include the amount
used for sprinkling the lawns around the plant.
The responsibility for maintaining a completely
treated sewage suitable for sprinkling purposes rests
upon the plant operating personnel, including stu-
dents, under the supervision of Mr. Lohmeyer. The
irrigation pump at the lagoon is never operated with-
out prior approval from the operator on duty. No
taps or spigots are included on the irrigation distri-
bution system, and all sprinkling heads are attached
only for the period of use.
Use of the plant effluent for lawn sprinkling and for
irrigation has been very successful. There is quite a
contrast between the campus lawns sprinkled with
the effluent and those receiving the same quantity of
water from deep wells which are located on the campus.
It is believed that this may be attributed, in part at
least, to the amount of nitrogen in the effluent. No
odor complaint has been received.
As an additional conservation measure, arrange-
ments were recently made to utilize the treated effluent
at a liquid air plant constructed at the sewage treat-
ment plant. Specifically, the reclaimed effluent is
being used as cooling water foi a 3 horsepower freon
refrigerating machine and for a 4-stage compressor
powered by a 50 horsepower electric motor. The liquid
air plant has a capacity of 15 liters per hour.

Other uses
In addition to their use for agricultural and in-
dustrial purposes, sewage effluents are also used in
some areas for the replenishment of ground water sup-

plies. The Department of Engineering of the Uni-
versity of California at Los Angeles has been conduc-
ting valuable research on the recharge of ground
water supplies, in which lagoons and percolation beds
have been used extensively. These studies were spon-
sored by the State Water Pollution Control Board
and the results were published in 1954.5 The studies
were undertaken "in the southern part of the State
where water sources for agriculture, domestic, and
industrial use may soon be a limiting factor in the
growth and development of the area, and in this region
the use of waste water may become feasible on a
large scale."5

Potentialities in Florida
Although the conditions in most parts of Florida
are not analogous to those in California, this writer
feels that some of the reports on Florida water re-
sources have been more optimistic than realistic, and
that the utilization of waste water to replenish ground
water will ultimately become feasible in some parts
of Florida, particularly in those areas where the aquifer
consists of waterbearing sand and where salt-water in-
trusion has already become a problem (e.g. the cit-
ronelle formation consisting chiefly of sand and white
or iron-stained clay in west Florida).
Even when ground water is obtained from porous
limestone formations where pollution is known to
exist (e.g. Gainesville and Lake City), it should be
better to replenish the aquifers with reclaimed water
from sewage that has percolated through sand than
to continue the present practice of discharging sewage
effluents into ditches leading to sinkholes which are
connected with the water bearing stratum. It should
not be forgotten that when dye was placed in the
effluent from this campus about eight years ago color
showed up in a city well a mile and a half away within
ten hours time. Neither should it be forgotten that
after heavy rains contamination continues to show up
in the raw water at the City of Gainesville softening
plant; nor that a new well supply and softening plant
had to be abandoned a few years ago in Lake City
as a result of sewage contamination which entered
through a sinkhole similar to the ones in the Gaines-
ville area. While, therefore, there are major objec-
tions aesthetically to the idea of using reclaimed water
from sewage to replenish ground water supplies, the
problems of reclamation should be approached realis-
tically, with due regard to the conditions that already
exist. Furthermore, it is almost axiomatic that Florida
will use more water as more air-conditioning units are
installed-to say nothing of its potential expansion
industrially with the advent of nuclear power.
Problems of reclamation should not be approached

with complacency or with the idea that our water
supplies are inexhaustible. According to Garald G.
Parker, the fresh water of the coastal area near Fort
Pierce "was once supposed to be an inexhaustible and
dependable supply." Yet one of the wells there
started showing evidence of salt water intrusion only
two years after it was installed.6 Also Tampa had to
abandon its subsurface supply, and Miami and St.
Petersburg have had to move their wells further in-

Everyone is familiar with the old saying that "neces-
sity is the mother of invention," and it is true that the
reclamation of water from sewage has resulted from
some measure of necessity. It is an ill wind that blows
no good, however, and we should recognize that the
reclamation of water from sewage has proven helpful
in many instances. Although sewage effluents contain
nitrogen, phosphates and potash, and they have some
fertilizing value, this virtue is sometimes overesti-
mated and the water rather than the organic content
is the controlling factor.7 Perhaps the greatest advan-
tage is that the cost of the reclaimed water, as at the
Bethlehem Steel Company near Baltimore, is signifi-
cantly less than that of other water sources. In deter-
mining reclaimed water costs, however, part or all of
the cost of disposal should usually "be assessed against
the disposal operation, with only those charges in ex-
cess of the disposal cost being assessed against the final
water user."8
There is also another important aspect that should
be considered. In general, the construction of a sewage
treatment plant is the last type of civic project that a
municipality will undertake voluntarily.9 Furthermore,
many municipalities and even some engineers resist
the efforts of the State Board of Health to obtain a
degree of treatment that will be adequate to prevent
nuisance conditions. It is just possible that a judicious
development of more reclamation projects may over-
come some of the antipathy or prejudices against
sewage treatment, and any development which may
assist the State Board of Health in their efforts to
protect the health of the citizens should indeed be a
Finally, it is believed that a more widespread pro-
gram of reclaiming water from sewage should result
in better operation of the treatment facilities them-
selves. Just as there has been a general reticence about
constructing sewage treatment plants at all, so has
there also been a comparable reluctance to pay the
superintendents and operators enough salary to insure
that high quality operation of the plants is obtained.
The savings that may accrue through better utilization

of the plant effluents should have a salutary effect in
this regard. Certainly it should be apparent that the
savings which result from the use of reclaimed water at
the University of Florida plant go a long way towards
paying for the high quality operation employed there.

Planning and Operation
Notwithstanding the foregoing, it should be recog-
nized that any reclamation project should be planned
and operated intelligently. For some purposes, the
quality of reclaimed effluents has been found better
than that of water from any other available source.
For other purposes, however, such reclamation may
not be justified economically; or, to put it another
way, water which is satisfactory for one purpose may
not be suitable for other purposes. For example,
water with high nitrates would not be acceptable for
a municipal supply because nitrates are suspected as
the cause of infant methemoglobinemia (blue babies),
but high nitrates are desirable in water that is used
for irrigation purposes. On the other hand, sodium
which is desirable in water for some industrial pur-
poses is undesirable in irrigation water because high
sodium ratios produce impervious soil conditions.
These are merely typical of many examples which
might be given to indicate that the basic principles of
engineering should be followed in recommending the
use of sewage effluents, and that widespread use of the
effluents should not be undertaken until all engineer-
ing and economic phases have been surveyed.10
One particular limitation on the use of sewage
effluents, or on their reuse as reclaimed water, is due
to an increase in minerals which usually accompanies
each use. In the California studies, the average in-
crement of total dissolved solids for 15 communities
was approximately 250 p.p.m., and a knowledge of
the mineral analysis of a water' supply helps in de-
termining whether the water may be reused safely.5
Almost every engineer is familiar with the classic ex-
ample in Kansas, however, where the total river water
used during the summer months by cities along the
Verdigris River was found by the Kansas State Board
of Health to be 17 times the total flow of the stream
at the state line, where the stream left the state.5, 11
Another impressive example is at the Kaiser steel
plant in Fontana, California, where the sanitary and
industrial waste waters are reused about 40 times in
the process of manufacturing steel.5 These examples
clearly demonstrate why the subjects of water puri-
fication and sewage treatment may not be successfully
divorced, and why sewage treatment is quite as im-
portant as water purification in the over-all problem
of water management, water resources, or water re-


Education and Public Relations
The foregoing examples may also indicate that
there was some justification in a poll taken three years
ago when sewage treatment plant operators in Florida
voted overwhelmingly in favor of trying to improve
public relations by using the term "water reclamation
plant" as a more decorous description of the utilities
they operate. In any event, it is true that the bacterio-
logical quality of some sewage treatment plant efflu-
ents, such as a properly disinfected effluent from a
sand filter, is better than the bacteriological quality
of some municipal water supplies. It is recognized,
however, that many educational accomplishments
must be realized before the general public will accept
some of the ideas of sanitary engineers on this subject.
A "destunk" skunk is considered an ideal house pet by
some people. There is little doubt that such animals
are affectionate and perhaps appreciative of the at-
tention given them, but the idea of having them in
the house remains aesthetically objectionable to the
great majority of people. On the other hand, the meat
packing industry has been quite successful in getting
public acceptance of "everything but the squeal"
from animals that are placed in cans. And some pro-
ducers of certified milk have had complaints because
of taste deficiencies attributable to the absence of that
trace of manure which is common to ordinary milk.
Much progress has already been made and the
need for water conservation measures is becoming gen-
erally recognized. One manifestation of this was a
statement by President Dwight D. Eisenhower at a
recent National Rivers and Harbors Congress. As
quoted by Professor Don E. Bloodgood in the De-
cember 1954 issue of Purdue University's Sanitary En-
gineering News, President Eisenhower said "I have
become convinced that before very long America will
almost unanimously look upon water as its single
greatest resource." In the same issue, Prof. Bloodgood
quoted Benjamin Franklin as saying "When the well
is dry, then we know the worth of the water."

Plans for the reclamation of water from sewage
should generally be cleared with the Bureau of Sani-
tary Engineering of the State Board of Health before
any project is undertaken. The indiscriminate use of
sewage effluents would be dangerous, and provision
must be made for the competent operation of any treat-
ment plant from which the effluent is to be reclaimed.
In addition to the usual health safeguards, the plants
should be practically free from odors, including those
from decaying algae.12 It is also important that steps
be taken to prevent mosquito breeding, as, for example,
at oxidation ponds and seepage lagoons which are

frequently used in the reclamation processes. It is of
interest to note that processes employing ponds and
lagoons are already recognized by the Florida State
Board of Health for the treatment of certain industrial

Summary and Conclusions
The practice of reclaiming water from sewage is
relatively new in Florida. It is not new in Texas,
California, and other western states. Nor is it new in
sections of some eastern states which have been faced
with water shortages. Under certain circumstances
it is feasible in parts of Florida, and it has been success-
ful at the University of Florida both for irrigation
and for an industrial purpose on a small scale. Recla-
mation projects should be planned intelligently and
operated carefully, however, and they generally should
not be undertaken without prior approval from the
Bureau of Sanitary Engineering of the Florida State
Board of Health.
1. Hutchins, Wells A., "Sewage Irrigation as Practiced in the
Western States," Technical Bulletin No. 675, U. S. Depart-
ment of Agriculture, Washington, D. C., March 1939.
2. Wolman, Abel, "Industrial Water Supply from Processed
Sewage Treatment Plant Effluent at Baltimore, Md.," Sewage
Works Journal, XX:I, Jan. 1948, pp. 15-21.
3. Goudey, R. F., Discussion, op. cit., p. 21.
4. Lohmeyer, George H., Private communication to the author,
Feb. 2, 1955.
5. Bush, A. F., and Mulford, S. F., "Studies of Waste Water
Reclamation and Utilization," Publication No. 9, State Water
Pollution Control Board, Sacremento, Calif., 82 pp.
6. Parker, Garald G., "Municipal Water Supply Problems of
Southern Florida," Proceedings of the Soil Science Society
of Florida, Vol. VIII, 1946, pp. 72-88.
7. Veatch, N. T., Jr., "The Use of Sewage Effluents in Agri-
culture," Modern Sewage Disposal, Anniversary Book of the
Federation of Sewage Works Associations, Chapter XVI, 1938,
pp. 180-190.
8. Rawn, A. M., Bowerman, F. R., and Stone, Ralph, "Integrat-
ing Reclamation and Disposal of Waste Water, Journal of
The American Water Works Association, 45:5, May 1953,
pp. 483-490.
9. Kiker, J. E., "Sewage Treatment Problems of Florida Com-
munities," Municipal Government Problems of Interest to
Florida, Studies in Public Administration No. 4, University
of Florida, 1950.
10. Powell, Sheppard T., "Some Aspects of the Requirements for
the Quality of Water for Industrial Uses." Sewage Works
Journal, XX:I, Jan. 1948, pp. 36-50.
11. Veatch, N. T., "Industrial Uses of Reclaimed Sewage
Effluents," Sewage Works Journal, XX:I, January 1948, pp.
12. Greenberg, A. E., and Gotaas, H. B., "Reclamation of Sewage
Water," American Journal of Public Health, 42:4, April 1952,
pp. 401-410.
13. Sewerage Guide, "Instructions Regarding Preparation, Sub-
mission & Approval of Projects for Sewerage Facilities," State
Board of Health, Jacksonville, Fla., Dec. 1, 1954. (Section
N, p. 75).

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