|
Reprinted fro the Journal of the New England Water Works
Association, Vol. XL, No. 2.
Copyright, 1926.
By the New England Water Works Association.
NEW WATER SUPPLY SYSTEM AT TAMPA,
'FLORIDA
BY
NICHOLAS S. HILL, JR.
Consulting Engineer, New York City.
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA*
BY NICHOLAS S. HILL, JR.*
[Read February 9, 1916.]
HISTORICAL. ,
Territory Supplied. Tampa, which claims the greatest population of
any city in Florida, is located on Tampa Bay at the mouth of the ls-
borough River. The city has enjoyed a continuous and rapid gr wth
throughout the past forty-five years.
The 1920 Federal census gave Tampa a population of 51 608. est
Tampa, which immediately adjoins it on the west, had a population of
8 463 in that year. The population of the Tampa water district, whichh
includes Tampa, West Tampa, and environs, was, in, 1920, 69 589. (The
state census of 1925 recorded approximately 95 000 people in old Taspa
alone, an increase of 84 per cent. in five years. The estimated population -
within the present city limits of Greater Tampa is 150 000.
Tampa is a city of substantial industries and resources. Tha its
recent phenomenal growth is not wholly the result of the recent Fiqrida
real estate boom, with which all are familiar, is apparent from a considera-
tion of the following figures, all but the last of which are taken from Federal
census reports. The figures apply to the population within the old city
limits.
Census Year. Population. Increase per Decade. F
1880 720 i
1890 5532 668%
1900 15839 186%
1910 37782 139% ,
1920 51608 37% J
1925 .95000 168%
Tampa Water Works Company. Until 1923, when the plant was pur-
chased by the city, the Tampa water district, including Tampa, West Tampa,
and environs, was served by the Tampa Water Works Company. At that
time, only two and one-half years ago; the population in the district 'Was
estimated to be 83 500, but two-thirds of the present estimated population,
and the population served 73 500.
The company was organized in 1887 by Messrs. Boardman and J ter.
A thirty-year franchise with a five-year extension privilege was secred.
Later, the property passed into the hands of the R. D. Wood Company,
who controlled it until the date of its,acquisition by the city.
Under the franchise the city had the option of purchase, and for many
Consulting Engineer, New York City.
Ii
yeas t rei
th gura
u Mr,
W (ksom
tw seel ted
the fingn
at cos of'
Th< c1n
P, P pinj
at ie c rnei
wa obti ned
Pul m pin
a the waia
A iue ind.
ab do d a
is s adr
Th sprig gw
:n 1 02,
lan Av nue
tio this stat
ma ly Uibi3
No:3. Of fh
the mainin
the ater ob
co c ion.
In 1916,
to milon
on e wl
low ve sto(
site he 4
and Twnty-
12-i well 2
Oth rsub-sta
sect ns of th
The depths a
'Of a totA
but 4 were,i
the 4hut fe
gen al distri
e san
it hard a
fror 250 to.
mill. The
ing une, 191
ILL. 129
ras a station and negotiation toward this end. In 2, after
tion f a commission form of government, a plan agreed
llen Hazen and the author were selected by the Tani Water
any nd the city to represent their respective interest These
Col. William J. Wilgus as the third arbitrator. Bid upon
Sthe property was taken over by the city on Auguai 1923,
1 35 722.
anhad, in all, three central pumping stations, of ich only
tion No. 3, was in use at the date of sale.
SStaion No. 1 was built in 1888 on the present sta ipe lot
of Hgenderson and Jefferson streets (see Fig. 1). Tli supply
front local wells, long since abandoned.
SStation No. 2, built in 1889 for the purpose of mal*g avail-
r of *agbee Spring, was located near the corner of Highland
Eenc rson Street (see Fig. 1). This station was ob4jete and
; the iate of sale, but the water from Magbee Spring ras and
gula ly, after chlorination, in connection with StatipS No. 3.
water ib hard and.the safe yield only 500 000 gal. per 4c.
Station No. 3 was bui t opposite Station No. 2, betwe4s High-
and the Hillsborougk River (see Fig. 1). Since its bnstruc-
on hps constituted the principal source of supply. $Approxi-
10-in. wells have been drilled in the vicinity of,Station
lese, about 20 were in serviceable condition at the da* of sale,
S10 having been abandoned because of the high sanity of
aine from them or, in a few instances, because of perfect
Their depth varies from 165 to 328 ft.
because of the grow in consumption, which then amounted
l. r day, it became necessary to equalize the rateof draft
d alo to supplement the supply. A 3.5 million galeconcrete
ge d equalizing reservoir was therefore constructed oppo-
n, ad a new well source was developed at Seventh Avenue
fifth street, 2 miles east of, Station No. 3. This was a single
15 ft deep, operated by a motor-driven centrifug(g pump.
;ionsof similar design were later constructed in this asd other
city n an effort to keep pace with the mounting conahnption.
the new wells varied from 235 to 530 ft.
I of 15 wells drilled by the Tampa Water Works Company,
usd at the time the property was acquired by the tity. Of
v haf consistently delivered witerwhich was suftable for
butioll.
y quality of the well water was fairly satisfactory, but:
d exceptionally high in salinity. The hardness saeraged
Sjrts per million and at times exceeded 700 $rts per
salir ity varied with the rainfall and rate of pump Dur-
2, itreached 1470 parts per million, expressed as chlorine,
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
it
i'i
[ j
HILL. 131
was unplatable, And bottled water had come into quite genera use for
dridking'pu poses.
REPORT ON NEW SUPPLY.
iln 1923 the average daily pumpage from wells was 7.5 mn on gal.
per ay. The su sequent increase to 12 million gal. per day in :125 has
for the to ploy every expedient to avert a famine until s uh time
as anew anadeq ate supply could be developed and placed in operation.
Nez Sti es investigated. The city officials were early alive to the
ne t of evel ping a new source from which an adequate vime of
water of oved quality could be obtained. As early as 1922, nkre than
a year b fo the i tual transfer of the property, the author waa stained
to invesigi te am report upon all available new sources. ExTustive
e o extending over a period of 18 months, were m e. All
p bible s within a reasonable disene of Tampa were stud The
stu ies ed survey of ground water conditions, daily flow measure-
me t gs and surface supplies, surveys to determine the ovationn
of r profiles for transmission lines, as well as the regular cemical
and bac gical analysis of all waters.
isou Ilede. As a result of these investigations the HilllArough
River ws Lally selected for development. The recommendaon was
b upon e large supply aviilable.and the low first cost and qierating
c as o rewith the other sources considered. The site clsen for
the umin ttin and treatment plant is 6 miles from the center of town
and .5 mile ptra from a dam and power plant owned by the Tampa
Ele rc o anysee Fig. 1).
Se drainage area above the point of intake is Z35 sq.
mil, m f wch consists of swamps and entirely undevelo i* land.
Th ve is by number of springs, the largest of which, CrystaAfprings,
flo fro to 4) million gal. per day. The dry weather flow at the in-
tak oriin wa i estimated at. 50 million gal. per day. Studio of the
re en f eriv r are still being carried on, and it now appears iat the
i a fth4 minimum flow may be increased considerably.; : during
the an se a ow of 600 to 700 million gal. per day is usual.:
e pla is located near the shore of the lake formed by the
Tic C mpany's dam. The lake, which is 12 miles in length,
im unc 65 billi n gal. below the top of the flashboards. By. securing
the eight toidraw pon this storage, which has slight value for poaer pur-
Sthe s fe yie d of the river at the new water works intake may be
inc asked c der bly above its minimum flow.
uaity f We er. The sanitary quality of the untreated rivlr water
is g d. ougl softer than all of the other supplies considered, this one
als req 'soft ing at some seasons of the year. During te rainy
se n e amp overflow and.a highly colored soft water result, while
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
during the dry season, when the flow is mainly derived from sprints'the
7 color is low and the hardness, high.
The variation in the quality of the water at different seasons may be
seen from the following:
S PArBT PZpR MILLION.
Rainy Season. Dry Season.
Color... ............................20. .......... 25
Total hardness.......... ............... 25........... 200
Alkalinity ............................. 24 .......... 140
Sulphate hardness ....................... 1........... 60
Turbidity ............................... 1........... 0
The relationship between color and total hardness is well illustrated
on Fig. 2. The curves cover the period from June, 1923, to Septe aber,
1924, during which from 1 to 4 analyses per month were made.
I I I I I I II \- -i-
S'0 ,' I \ -.
o It 1 Io
--------------------------- --a--
/I AI\I ,
1 so i i js i x "
116 -=0-- A tS^
40
JUNE JULY AU6. SEP OCT. NOV. DEC. JAN RPE MAr AtIL PMAY JUNE JULY AU~'ti
19s_ 1.t4
i0
2o
SFIG. 2. RELATION BETWEEN COLOR AND TOTAL HARDNESS.
EXPERIMENTAL TREATMENT PLANT.
It was early realized that, owing to its widely varying character tics,
the Hillsborough River water would be difficult to handle. In ord r to
determine on the best methods of treatment, an experimental plant having
a capacity of 25 000 gal. per day was erected in August, 1924. The p oto-
graph, Fig. 3, presents a general view of this plant.
It was equipped with the necessary pumps, six mixing tanks with
motor-driven impellers, six-hour sedimentation basin, three carbon4ting
tanks equipped with pipe grids and filtros plates, a gravity filter and a klear
well. A series of experiments was carried on to determine the best arder
of treatment, the. minimum quantity of chemicals required to produce
results, the proper mixing and detention periods, etc. The plant was
S !HILL. 133
operated iitil Fbruary, 1925, by which time a complete cy t of the
water had en studied. In order to overcome a local prejudi against
NEWWORKS.
Ge esciption. From a study of the relation betweekt, quality
Iani rats f s umpage, it was determined that a supply of apprhm lately
6 millio g per day could be drawn from the existing wells without secur-
ing an xe jvely hard or saline water. The new plant was, therefore,
d; e of nominal capacity of 12-15 million gal. per day, giving a total
c ti |nt capacity of 18-21 million gal. per day of soft water, low
in ior salty. With the overload capacity and storage te plant
wilGme Iloads of 25-27 million gal. daily.an
STh n works, the construction of which was begun in Augprt, 1924,
6 ust n bei d completed. They comprise an iintake, a combined sw and
Shi lift pp ping station; a treatment plant for softening, deodlorizing,
irec b iaai; and filtering the water; a 30-in. cast-iron force n some
te es length, and three one-half million gal. elevated storgiv tanks.
STh ge ral layout of the pumping station and treatment plant is
sho ni 4. .
Fig re pshowas a general plan on o la more detail on a
s ca r s le.c d ow
cher ica s ar completion, a spur track was built from the Tampa northern
Ra way o half mile distant, to the treatment plant site.
Tre t Processes. As has already been mentioned, twb widely
134 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA. ;
"" \j! X
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i
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I ; HILL. 135
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1d0 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
different waters, together with all intermediate gradations, are met with
at Tampa. This requires what amounts practically to two treatment
plants in one.
Decolorizing. The most important treatment is that for color re-
moval. Aluminum sulphate and sulphurous acid are used to accomplish
this. Heretofore' aluminum sulphate alone generally has been used for the
purpose. However, this chemical is expensive and when color, ranging
from 100 to 200 parts per million is to be combated, the cost is almost pro-
hibitive. By the addition of sulphurous acid, the alkalinity may be.neu-
tralized and the hydrogen ion concentration raised to a point where the
most complete precipitation of the aluminum sulphate as aluminum hy-
droxide takes place. As a result, a much smaller amount of aluminum
sulphate is required for the complete removal of color than when aluminum
sulphate is used alone. Lime or, soda ash, added after filtration, again
lowers the hydrogen ion concentration and cuts down the amount of free
carbon dioxide in the water to a point where the water can be distributed
safely without danger of corroding the distribution system.
Softening. During a portion of the year softening is required in
addition to the decolorizing treatment. The flexibility provided in the
design of the sedimentation basins makes it possible to change readily from
a decolorizing to a decolorizing-and-softening plant. By the use f hy-
drated lime the carbonate hardness is thrown down. If, in addition, the
.water has a sulphate hardness, soda ash is added to reduce it. The water
then passes to decolorizing tanks and basins where aluminum sulph4te is
added. The aluminum sulphate lowers the causticity due to the addition
of the lime, and removes the color. The water then passes to a carbonkting
chamber. i
Recarbonization. It is believed that in recarbonization has been found
the solution of one of the most perplexing problems in modem water puri-
fication. The demand for soft water has reached such proportions that
it cannot be ignored by those responsible for the design of present-day
purification systems. This has been recognized in the Tampa plant where,
by the introduction of recarbonization, the evils of the usual softening plant
have been avoided. Recarbonization eliminates the reprecipitatioh of
calcium carbonate in filter underdrains, distribution system and meters and
the so-called sand growth, and gives a more palatable water. The amount
of carbon dioxide introduced can be regulated accurately by the chemist
in charge, so that the water, as delivered to the consumer, has the pfede- |
termined content necessary to give the most satisfactory water.
Pumping Plant. The pumping plant, of 25 million gal. instilled
capacity, consists of an intake and a steam-pumping station containing a
boiler room and two-level pump room.
Intake Works. A concrete intake chamber, 31 ft. in height was pl ced
in the center of the river channel, in approximately 25 ft. of water. It has
three openings controlled by 48-in. sluice gates, and protected by $.in.
by in wc
flow thr ugh
screen a
inch scre ns,
fro entering
Sin cast
plaig and r
,Pon ecti
lows tig tb
suction f
loeig f*l
S137
HILL
ught-iron bar screens. From the intake chamber, tne water
a 36in. cast-iron intake pipe, approximately 225 ft. Ib*g, to a
tion well adjacent to the pumping station. Here oneuarter
constructed of- No. 16 B. & S. gage copper wire, prevst trash
the pump suctions. The copper screens are set in ngs of
iron stop plank grooves. A ha ton hoist is instead for
moving screens. *-
)ns have been provided so that, in the event on unusual
e water in the reservoir, pumping may be carried on direct
he intake.
Fro. 6. RIVER NEAR INTAKE.
,The h graphs, Figs. 6, 7, and 8, show the river near the point of
intake a t intake chamber. At the time the photographs weir taken
the aate] lev I was low due to the previous failure of the Tampa electricc
Co anw 's dm which has now been rebuilt. The material seen setround-
ing e take in Fig. 8 is not the top of a gravel bar, as might be sitposed,
but oatg auatic plants which abound in the river at certain se Wons. -
p ium ing Station. The pumping station is of hollow tile const iction,
stuced, witl red tile roof (see Fig. 9).
I'he oile room contains three Babcock and Wilcox.water tubi boilers,
rate at OO I. P each. Space is provided for a fourth boiler. Boilers
are signed r th use of fuel oil, but are so arranged that a chae can
rea y ma e to oal if, in the future, this becomes economically dcirable.
W. B st st am ,tomization burners and equipment are used.' team is
furhed at 1 5 Ib pressure and 1000 superheat.
a :i I
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
FIG. 7. INTAxE.
FI'. 8. INTAK.
.
SHILL. 139
Oil is rou into the plant in tank cars which are placed a a siding
about 800 fro two fuel-oil storage tanks adjacent to the balkr room,
to ihich t e oil fows by gravity through an 8-in. filling line. The tanks,
eali of 500 ga. capacity, are enclosed by a concrete retainingwall, and
eqp th stam-heating and steam-smothering lines, tempeure reg-
ul ors, an pne ercator gage for determining the amount of oI|n hand.
Th I -lift umps are located on a lower floor of the pumpia station.
Tse e wo 1.5 aid one 6.5 million gal. per day de Laval c ntrifugal
puiips, ri en b de Laval steam turbines. They operate against a head
of0 ft p king p the water from the screen or low-lift suction well, and
puping 'i to t treatment plant. Two 50 kw. direct conneeded, non-
FIG, 9. PUMPING STATION.
condensing stea -engine-driven generators, located on this floor furnish
c rent fo 'ghting the plant and for the various motor-driven equipment.
AI water wiping 'n the low-lift pump room is carried below tlh floor in
tr ches h ving decker plate covers. This gives unrestricted )eor space
an an att active appearance, while at the same time access to piibg is not
'ficed.
The hh-ift pumps are placed on a nezzanine floor, at ground level
an 10 ft. jbove e level of the low-lift pump room. The presea4installa-
tio consissof o 10 and one 5 million gal. per day de Laval two-stage
ce rifugal ump, driven by de Laval steam turbines. The pumpi operate
ag nst a d of00 ft.
On th floorjare located the gage boards, Venturi meter re$gter, etc.
F etes and Venturi meters register the volume of steam consumed
waer um by the low-lift, high-lift and wash-water p4*ps. In
fa ,l all opratio throughout the plant are fully metered. A wah-water
st e editor, gether with alarm bell and light and a filtered water
res rvo s e indicator, are also located on this floor.
I 1
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
* f
* 140
HILL. 141
rhe sp ce on fhe lower level underneath the mezzanine is d'ted to
the Ionener a d wash-water pumps. Three Wheeler surf6e con-
den rs, equipped with steam jet air pumps capable of maintning a
28-i. vacuum, are used. Each of the three condensers receives the exhaust
fron0a high nd a low lift pump. Cooling water for the condensers i taken
frothe lo lift mp discharge. As the temperature of the rive water
cl y app ximat a that of the air, it was felt that it would be untsirable
tos1 firtr inci ease the temperature of the water supplied to #te city.
For is ron, te cooling water after leaving the condensers ~carried
to a ewEr ad wa ed. Duplicate 350 gal. per minute water mot#*driven
a-waer ump have been installed. These are automatic con-
trolld b as reg ator valves operated by water pressure from tS wash-
wat4tt .
he p iping station is so arranged that from the high-lift por the
engi eer watcl the operation of the entire pumping plant. ,ie low-
lift ad gepi rators on the lower level are in full view of the operator.
Ope tios the condenser room may be seen through openingi.in the
mez r e fl or. l gages are located on or plainly visible from tl~ floor.
ie 0O shews a longitudinal and transverse section threVgh the
pu ing sta ion. 'Figure 11 is a plan of the pumping equipment ad main
pipi g. g e 122 is a photographic view taken from the floor of the low-
lift i T m. I, shows the high-lift pump room above and the ~ondenser
roo b w he mezzanine floor.,
tPnt. The treatment plant of 12-15 million ggL initial
rate ca acy has been designed so that by the addition of new tmits the
cap ity ka r readily be enlarged to 36 million gal. daily without ipairing
the iymne y. T\he plant comprises mixing tanks and sedin1dhtation
basic s, checal house, filter house, gravity mechanical filters, and filtered
water reservr.
Mixng Tanks Eight lime-mixing tanks, each 24 ft. square, and eight
aluminum s phat( mixing tanks, each 18 ft. 8 in. square, have been con-
stlrued.] I ach mixing tank is provided with a bronze impeller 'et in a
14-i draft ube and operated by a'one-horse-power motor. Ea& motor
is c"trolle by a! individual switch. As no covering .is proved for
mix tank or sedimentation basins, the motors are protected by copper
hoo Tw mixing g tanks, separated by a top baffle, are always used in
seri The chemical solutions enter the mixing tanks through an orifice
box ro de with brass orifice plate, so as to give equal dosage to pi tanks
in u .
edi tionasins. Two lime-settling basins, each of.one millionn
gal.apa t or sicient to give a 4-hour detention period when operating
at t e n rate and two decolorizing basins, each three-quartrs of a
.n paeit r, giving a detention period of three hours, are provided
(see ig 1 14, id 15). As previously stated, these basins ca-be used
eith in ere or i parallel.
142 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
I .; %
HILL. 143
FIG. 12. INTERIOR or CONDENSER ROO.
FIG. 13. PIANT DURING UoNSTRUCTION.
FIG. 14. SETrLING BASIN.
B
144 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
A novel sludge drainage system has been installed as indicates on
Figs. 16 and 17. Through the first half of each settling basin, a serial of
lateral drains, consisting of 6-in. vitrified bell and spigot pipe tees, have en
laid in the floor of the basin, with the branch of the tee pointed up an et
flush with the finished floor. A 6-in. vitrified plug, with a 1-in. orifice, Was
placed in each bell. Sloping concrete ridges separate the rows of 1ipe.
The underdrains are connected up to the headers at the side of the brain
which collect and discharge from sections consisting of five lines of unjir-
drains. Each header is controlled by a gate valve and discharges in a
12-in. cast-iron pipe leading to the sewer. By opening the gate valve,,lthe
water in the basins is utilized to flush out the sludge which has ien
Deposited over the bottom of the basin.
FIG. 15. SETTING BASIN.
An interesting feature of the sludge drainage system is that it m'
be backwashed with water under moderate pressure so that if the slude
surrounding the drains becomes hard or caked it may be loosened. As:i
great portion of the sludge is deposited in the first half of the basins, it wp
not considered necessary to continue this construction through the second
half. A 4-in. flushing line with hose nozzles has been provided for cleanij
this portion of the basins. I
Conduits. Because of the wide variations in the character of the water
to be treated, a great deal of attention was given to the attainment of
flexibility in operation so that any order or combination of treatment would
be possible. This flexibility is secured by means of an additional conduit
serving the various mixing tanks and settling basins, together with addi-
tional inlet and outlet openings controlled by stop planks.
Figure 17 shows the construction used. One wall along the mixixi
tanks and settling basins has been made double and contains a bank of foit
conduits. The upper or raw-water conduit conveys the raw water to any
!' f
HILL.
NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA,
I:
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group of nixAig tanks, as desired. The second, or settled water duit,
i conve's the settled water to the filters. The third, or transfer cond is so
i arranged that wader may be taken from any one settling basin I dis-
chargqd ingo ny other basin. In this wa, basins may be used in allel
Fio. 18. FIurER &ND CHEMICAL HOUsE.
or in series.' he lowest conduit leads to the sewer and is used to dispose
,of the accunmulted sludge.
In the top of the.upper conduit, 12-in. and 15-in. half round tile pipes.
encased in concrete have'been placed (Fig. 17). These conduits aGvey
FiG. 19. CamcaL HoUsE.
tie chetiical so ,tions to any desired mixing tank. Access to the tr~ hs
i proved at f euent intervals by choker plate covers. 4
Ch nici use. The chemical house is a two-story re.nforcedi)on-
: II '' '
148 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA. |
SP "T 1-i ~
____________________ _____-- ______
-a i "
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l I
aS
a. V I.
ht
rig U
J t!
icrete ucur
(Figs. 18 a4d
room, r~etor r
to chemical st
Hate, oda an
coke ai st
the uper oo
storagel bind, w
one mhth'
giving cnts
i
149
with .stuccoed, hollow-tile curtain walls and red tiV roof
9). On the lower floor (Fig. 20) are located the unl ding
m, and chemical feed room. The second floor is doted
rage and handling. Freight cars, bearing alumin8nui sul-
lime, are brought directly into the building. Sulpht d and
in track bins just outside. Chemicals in bulk are ta to
in a bucket conveyor and discharged directly infi the
ch are of concrete and have a capacity sufficient toiold
pply. A hydraulic elevator is provided for chemical ar-
ers. ,A Koppel- industrial railway, with track scab'and
-+ ,,
S FIG. 21. ABso PTION TANK.
ge c, handles chemicals between storage bins and. hoppers.
in t room has been taken care of by large copper louters,
r b ze grills.
easptside of the room, and directly over the chemical Aed
Sco create hoppers are suspended from the floor. Two are for
ralu ninum sulphate,'and two for soda ash. Each hopper will
t on Iday's supply of chemicals. Discharge of the cheniais
pperi is regulated by Link-Belt bin gates.
emic 4 feed room contains six motbr-driven Gauntt dry fed
.ated.directly under the concrete hoppers. The metal hoppers
mahines fit tightly to the bottoms of the concrete hopjos,
Citing; dust at this point. The machines are of the manyUy
HILL.
150 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
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mean of o ater-
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conduit. w in
Sconcr t u un
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inside the ui ig a
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dioxi an nd
Sand 1oer ng ue
formi g s Ip di
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ing ( g. ).
e gi Ia terms
Wate is t ler pray
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Spacity of 2 lbs.
amou t of a d
mean 4of ca n
carboiizat ni rea:
chamber 1h ca un
i consist of ed
Floor; Iti ved
pipe id ith
tank fr a his i
Fi er o 1
Sbuildii g ( ig ).
tecturl d of th
{locate .in a -acre
Ivailinin tie l blic
extend ovrp t oft
1has n teat as a
crete alls ick-p
ppro h t mai
HILL.
:' 151
"IC
ire in duplicate, two of 1 000 lbs. per hour capacity for
per hour capacity for alum and two of 500 lbs. pot hour
i. Each pair is set over a concrete trough with water
Untreated water is pumped through the trouis by
motor-driven pumps. The water motors are ograted
ity supply which is discharged into the filtered ater,
eter registers the water used for this purposes The
ler the machines act as dissolving boxes for the ulemi-
conveys them to the point of application. I ughs
re open at the top for inspection and cleaning. >
n is adjacent to the unloading platform. S"phur
dioxide are made here. Sulphur is burned in two SWutte
s, of a rated capacity of 35 lbs. of sulphur peit our,
xide gas. An electrically driven Allen and B nyre
nection.with the combustion of the sulphur. gas gas
6cketed manifold from which it pases to the absaation
by 12-ft. deep cypress tank located outside the build-
;he upper compartment of this tank, which is b1ffed.
ad through it by Shutte and Koerting spray nizles.
the water forms sulphurous acid which is stored in a
*ption chamber. The acid is conveyed through lead-
ted orifice tank, located at the side of the alum t-"ghs
room. Acid is introduced into the same chn*ical
inum sulphate.
xide equipment was furnished by the Carbliale-
and consists of a coke furnace with a maxim d ca-
per day, a scrubber, and a small compressor. ; The
ed to the furnace can be altered as desired, and by
dioxide recorder located on the wall the process t re-
ily controlled. The gas is applied in a carboasting
;e the chemical feed room (Fig. 22). This chamber
compartmentt with a 1l-in, pipe grid placed alo the
that more satisfactory results will be secured wi the
the filtros plates, heretofore used. A baffled axing
dso located below the chemical feed room;
he filter house is a one-story hollow-tile and btcco
i great deal of attention has been given to thea chi-
is building and, in fact, to the entire plant, wlh is
city park. The Moorish-Spanish architectuppre-
Ruilding in Tampa has been adhered to, -The b#ding
lie filters only. The portion outside the building *alls
n open terrace, with what appear to be panelle icon-
aved steps and a walk leading to a terrace fo.r the
a entrance. The terrace is enclosed by a casone
152 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
balustrade and is set off by stone benches and plantings. Cast-stone auns
are set on the balustrade posts. The trim around the doorway is of cast
stone. Inside the operating gallery a very attractive appearance has F)en
attained by eliminating the usual roof trusses and placing suspended arched
ceilings. These ceilings and the walls are of grey gypsum plaster *with
monitors and large windows, making the gallery light and cool. I
In the design of a plant to be located in a semi-tropical zone it i as
imperative that great attention be paid to securing cool, well-ventilated
buildings. This has been done at Tampa by the construction of do le
roofs throughout the plant and by the careful arrangement of ventila Ors,
monitors, and large windows. The results obtained in the lobby: and
FIG. 23. FLTER HOUSE.
operating gallery are striking. The appearance is entirely dissimilar t the
usual filter gallery, impressing one as a cool, spacious stone cor ror.
Utility, however, was not sacrificed to obtain this effect, and the added
cost for the treatment was negligible.
Low parapet walls enclose the filters, upon which are set cast-sme
spijal-twisted columns. These columns are utilized to conceal the strucltural
steel columns, rain-water leaders, and electric wiring. In the entrance
lobby is located a low fountain decorated with colored faience tile. Two
cast-stone lion's-head wall fountains, set in recesses bordered by colored
faience tile, are placed on the rear wall on either side of the doorway leailing
to the offices and the chemical house.
Laboratory and Offices. By means of a corridor the filter gallery and
the chemical house are made into what is really one large building (Fig. 6).
Along the corridor are located the laboratory, office, chlorine room, ind
lavatories. -
The office of the Superintendent of Filtration is located so that Mth
but a few steps he may oversee the entire plant operation. The laboratory
'~~ '
153
I Il
154 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
T r i
------ i-- "
I -i I ,
i "
: -
i i K
r
HILL.
'155
156 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA. i
is directly across the hall. The entire filter gallery can be seen freif the
corridor. An alarm bell and light located there indicate the level of the
water in the wash-water tank.
At the other end of the corridor is located the chlorine roonj ;nd
chemical feed room. The raw-water Venturi-meter register, and pther
recording apparatus, are also located there. The retort room, chemical
storage room, mixing tanks and settling basin are close at hand. The
chemist in the laboratory also shares this central location.
The laboratory has been planned to afford a compact and convenient
Arrangement of the laboratory apparatus. Lighting and ventilation1 here
-s-,
9ETAIL OF .TRAINERP/PNG.
DETAIL OF C R
DETAIL OFCl $S4C1ERS
_'__: I
ARRANGEMENT OF qTRAI#RVS AN X;!fwn q. '.
FIG. 27. S ,TRINER SYSTEM.
and in the offices are taken care of by means of large window openings and
roof monitors. Corridor sash allows ventilation across the entire width
of the building. This, together with the double roof, should add grea y to
the comfort of the occupants.
The chlorine room contains two Wallace and Tiernan vacuum type
M.S.V. chlorinators, feeding chlorine directly into the filtered water conduit
which passes underneath the room.
Filters. Eight concrete gravity filters, having a normal capacity of
1.5 to 1.75 million gal. each, are included in the present installation.
The influent to the filters is carried in concrete ducts along their o iode
walls, thus relieving the pipe gallery of that much of large piping. The
filters are built in two sections, having a combined area of 600 squ e ft.
HILL. 157
separated by a deep, central trough which serves the ible
At foi the settled water and an outlet for the wash w
most interesting feature of the filters is the strainer .
diameter cast-iron pipes are used for this (see Fi 7).
,boyv the floor bI lugs cast on the bottom of the pi hus
ly a continuous horizontal orifice, -in. wide on bot
all hples in the top at each of the pipes provide f'the
ed ar.
of gi avel, varying in.size from 2j in. to A in. in si*sind
.n d pth, cover the lateral pipes. Thirty inches of nd,
FIG. 28. WASH WATER TANK.
e size of approximately 0.4 millimeter and a uniforO*ty
oximately 1.6, surmount the gravel.
ter troughs are of concrete having half-round upper ef es.
if Tennessee marble with slate tops are set directly in bnt
11 filter valves 4re hydraulically operated and conti ed
Stables, on which are placed the valve position indicprs
he rate of flow, loss of head, and recording gages. 1
operating gallery is located the pipe gallery. Ac to
by means of two ornamental iron spiral stairways m'
utsile entrances at each end. The pipe gallery isi r-
lobst ucted passageways and freedom from a large a t
,ing. The wash-water pipe is suspended from the c g
er, wch is stored in a 100 000-gal. elevated tank (FigB),
eansf a Rose pressure-reducing valve.
158 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
Simplex controllers are used to control the rate of filtration. Thesehdis-
charge into control chambers located adjacent to a concrete filtered' waterr
conduit below the pipe gallery floor. The conduit carries the filtered winter
to the clear-water basin. Concrete sewers, installed underneath the ppe
gallery, carrythe waste water from washing and rewash to a 30-in. segm4atal
block sewer which discharges into the river below the dam almost a file
from the plant.
Filtered Water Reservoir. The filtered water reservoir is a covered
basin of one-half million gal. capacity. It is 94 ft. square and divided into
two compartments by an end baffle wall. Inlet and outlet manhole? are
connected by a 36-in. cast-iron pipe allowing the water to be by-p ed
around the basin. From the filtered water basin, the water flows rto a
suction well adjacent to the pumping station where it is picked up b$ the
high-lift pumps and pumped directly into the distribution system.
Landscaping. The new plant is located in the center of a wooded ark
embracing 55 acres, with about 2 000 ft. of lake frontage. Plans fo} the
development of the park with roads and tropical plantings have already
been made. A park boulevard linking it with a riverside drive and Other
.city parks is also contemplated. It is expected that the water-works plant
and park will be one of the show places in Tampa.
Terraces surrounding the basins and filter plant have been laid opt so
as to dispose of all surplus dirt removed from the excavations. These
terraces will be planted with grass, and tropical shrubbery and plantings
will be set out.
Transmission and Distribution of Water. A 30-in. cast-iron force iain,
approximately three miles long, carries the water into the city proper. j'The
main divides, upon reaching the built-up section, into two 24-in. $ines,
which parallel each other about one-half mile apart. Such necessary re-
inforcements of the old system as were required to give the proper distribu-
tion of water have been made.
Three elevated tanks, each of 500 000 gal. capacity, have been erected
in different sections of the city, thus equalizing pressures and reducing the
peak loads on the plant.
Fire Service Supply. The old 3.5 million gal. low-level covered con-
crete reservoir, previously referred to and adjacent to pumping station No. 3,
will be used to store a water reserve for fire protection. Two motor-driven
centrifugal fire pumps, each of 5 million gal. per day capacity, have been
installed in station No. 3. One of these pumps will be started as soon as a
fire-alarm signal is received, drawing water from the reservoir and pugtpng
into the distribution system. The development of excess pressures on'the
distribution system is prevented by the use of a Ross relief valve placed
on a by-pass between the suction and the discharge of the pumps.
Provisions for Extensions. The entire works have been laid ou.and
designed with particular attention to the making of extension. Estim ng
the future population of Florida cities is an uncertain undertaking be use
S. I HILL. 1 59
pf the ormous wth now talking place. For this reason, the pla as
first of ca ity of 36 million gal. per day. The present i -
tion w hn d gne as a part of the ultimate development. Co lts
d pi lies ere, general, llaid to take care of the enlarged t.
und onin e p ing station and boiler room were construct or
resent t designed to take care of larger units to be i ed
talatd i -
SIn e ei provision has been made to convert c Bin
ortio of he ins into mixing chambers without alteration of e ng
rct Con ts ave beeniprovided where required for the enle
plant, igh ot necessary t present. Openings have been le in
ncret w ani bri ed up so that no expensive cutting will be nece
during aem ts. Sewers, leading from both settling basins and f s,
ave ben c(ns tr ed of concrete of thesame cross sections as found er
e st ts. Upo enlargement, structures may be built ove e
wers *th ut iiterfng with operation. Similar provisions are f d
Sthe ter and cle-water basin. Keyways and dowels have bee ft
walls Atem ra closure of conduits or basins later to be extend ior
c e in zeas bn made bk bricking up openings or by use of flaid
pe an bik fl ges
Cop., n closing, a summary of the points in which this Ant
offers fm sual water-woris development may not be out of ple.
first, p c on to the chitectural details, providing except al
ntilat nd ghtg and combining utility with beauty; second 4he
anuf r use f sulphurdus acid and carbon dioxide gas; thi a a
w ty of lt trailer system; fourth, a simple sludge disposal sys(n;
th, cerazanan convenient control both in the pumping station *ad
e filtrl tior pt; sih, an unobstructed pipe gallery; and seventh, 6*n-
ehense ons or the futgire extensions.
Th coitrAtion of the plaht was carried on under fifteen sep wte
tract. e once and building work was performed by the Ga4ier-
orsmo Io Cos ~tion Company of Memphis, Tenn. The filter -d
emic a sw furnished by the American Water Softener (fan-
ny of phild hia, enn. Pumps, boilers, and pumping station pijng
re fui nd i called by Burford, Hall and Smith of Atlanta, (a.
t-iro fo d ds ribution wiping and the main waste sewer from the
ant wre id njamin ompson of Tampa, Fla. The elevated
tdnks were f ed a d erected by the Chicago Bridge and Iron Wor" of
Sicago, Ill. e pumping station chimney was built by the AlpkLns
Cstodis' C nr Coistruction Company of New York City. Cast4pn
pipe and fittg ere Furnished by the United States Cast Iron Pipe i4d
Fundry Co pany. Al valves wAre furnished by the Iowa Valve Cominmy
Cf Os8 Ia 'a. The spur tck was laid by the Seaboard Air ie
adlwayiCo p The found ons for one of the elevated tanks e
cnstruced y G rgeinger of ampa, Fla.
^ t 1 *".' '
160 NEW WATER SUPPLY SYSTEM AT TAMPA, FLORIDA.
The preparation of plans and specifications for the plant was in chge
of my associate, Mr. Horace H. Chase, in collaboration with my partner,
Mr. Stuart K. Knox, and my associate, Mr. A. T. Ricketts. Mr. George I.
Buck of my staff was.resident engineer and was assisted in the field by
Mr. E. L. Hyde and Mr. A. J. Barclay. Mr. Chase has also had general
supervision of construction. The,preliminary chemical and biological work
was in charge of my laboratory.
DIscussIoN.
FRANK A. MABsToN.* I would like to express my appreciation* of
Mr. Hill's courtesy in giving us this excellent paper. '
It was my privilege in January, 1926, to visit the Tampa plant, and
I was much interested in-the provisions made to give flexibility in operation.
It has been well provided for, and I think Mr. Hill is to be commended for
the excellent plant that he has laid out. It is, also, very attractive; in fact,
as it stands today it is one of the most attractive filter plants in the State /
of Florida. Various features of the plant which he has called attention to
are of special interest to those who have such plants to design. .
There are one or two things in particular which attracted my attention,'
one being the mixing tanks. The scheme provides motor-driven propellers
to agitate the water. It has been found in certain cases that after once
agitating water with altun, it should not be agitated violently again,i but
I notice that the mixing tanks are, as it were, in pairs, one propeller agit4ting
the water and chemical, and then after passing under a baffle, the water is
agitated in a similar manner the second time. I assume that the time
interval is so short that the second agitation will not have any objectionable
effects; but I would like to raise a question as to whether Mr. Hil has
experimented to see the effect on alum floc by that method of agitati n.
Another question occurs to me. What is the ratio of the area of the
waterways in the under-drainage system of the filters to the net area of
the sand? We are in the habit of thinking the ratio should be about 063,oi
0.5 of 1 per cent. for a perforated pipe system. It would be interestingito
know what the proportion is in the Tampa under-drainage system.
MR. HILL. In answer to the first question, the results we hav ob--
tained at the experimental plant seem to indicate that the secondary
agitation with the water we had to treat produced better results, and we
could use a smaller ,amount of chemical by so doing, but we also have
designed with a view. to making it unnecessary to have secondary agittion
if we find it advisable not to do so.
With regard to the other .question, I cannot answer you offhand, but
I wilLsay this: that the proportion is very much larger than in the ordihry
grid. I could not give you a definite figure without consulting my notes.
Of Metcalf & Eddy, Consulting Engineers, Boston, Mass.
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