Page 38 - 1915, Springs of CA.

36 SPRINGS OF CALIFORNIA.
TTRBITA HOT SPRINGS (SAN BERNARDINO 38).
About 1 mile south of San Bernardino a recreation park known as
Urbita Hot Springs has been built about a group of artesian wells that
yield thermal water. This water supplies a swimming plunge, tub
baths, and a small lake. The warmest well yields about 200 gallons
a minute of mildly sulphureted water that is said to have a tempera-
ture of 106°. The following partial analysis shows that, like the
water at Arrowhead and at Harlem springs, it is not highly mineral-
ized, but small amounts of sulphur and iron constituents in the water
cause it to stain the enameled bathtubs:
Analyses of water from Urbita Hot Springs and Harlem Hot Spring, San Bernardino
County, Cal.
[Analyst, E. W. Hilgard. Authority, advertising matter. Constituents are in parts per million
by weight.]
Urbita. Harlem.

Properties of reaction:
nant. nant.
0 (?)
0 0
(?)
Small.
Tertiary alkalinity. . ............................................................
Residue:
80 fin
310 260
25 on
415 410
Portion soluble in water:
Sulphate (8Qt). ................................................................. 133 144
Chloride (Cl) .................................................................... 21 10
Carbonate (CO3) ................................................................ 42 16
114 on
Portion insoluble in water:
Silica (SiOa).. ................................. .................................. 10 50
Calcium (Ca), magnesium (Mg), carbonate (COs) and sulphate (SO.)), chiefly
15 40
As has been previously stated, the area along the western base of
San Bernardino Mountains is a faulted zone. The issuance of hot
water within this area therefore seems to be due to a fault or struc-
tural break in the granitic rocks, which allows deep-seated thermal
water to reach the surface. The abnormal temperature of Harlem
Hot Spring is possibly due to leakage into the alluvium of heated
water that rises in the faulted zone. This may also be the source
of the warm water at the Urbita wells, though there is a bedrock
area 1 mile south of these thermal wells that may cause under-
ground alluvial water to rise from a depth sufficient to account for
its high temperature. Warm water is also obtained from other flow-
ing wells in this locality. The sulphurous elements of the water from
the Urbita wells are probably derived from material in the alluvium