162 



DONALD W. STRASBURG 



USE AND PROPERTIES OF WELL WATER 



Because of the iinsuitability of these 

 sources, two salt-water wells were drilled 

 at Kewalo in June 1958. The bores passed 

 through hard-packed coral and sand to 

 depths of 77 and 67.5 feet, of which the 

 upper 42 feet were lined with 3i/^-inch 

 casing (fig. 2) . In November 1958, pumps 



GROUND 



3'/fe"CASING- 



41.9- 



3 OPEN HOLE- 



69.0- 



2 OPEN HOLE- 



77.0'- 



SURFACE 



HARDPACKED CORAL AND SAND FILL 



-5.0' 



-SOFT MUD, SAND AND SMALL CORAL 



-38.5' 



-44.0' 



-53.4' 



-FINGER CORAL HARDPACKED 

 WITH SAND AND SHELL 



-TREE CORAL HARDPACKED WITH 

 SAND AND SHELL 



-MEDIUM AND HARD CORAL ROCK 



Figure 2. — Diagram of Kewalo well and sur- 

 rounding stratigraphy. 



were fitted to both w^ells, and studies were 

 begun on the fitness of the w^ater for main- 

 taining various fish. Heavy pumping 

 caused the shallower bore to become im- 

 pacted with sand, but the 77- foot well has 

 been in nearly continuous operation since 

 that time. About 35 million gallons had 

 been pumped in 20 months at rates vary- 

 ing from 30 to 45 gallons per minute. At 

 these rates the drawdown of shaft water 

 level was only 0.4 feet. Some properties 

 of this w^ater are listed in table 1, along 

 with similar data for the Honolulu Aquar- 

 ium well (3 miles from Kewalo) and 

 oceanic water. The Kewalo and Aquar- 



ium samples were drawn on December 10, 

 1958, while the ocean water values were 

 compiled from various sources, including 

 the Honolulu Board of Water Supply. 

 The analyses were performed by Y. F. Lee 

 of the Honolulu Board of Water Supply, 

 to whom I am indeed grateful. 



The Kewalo and Aquarium samples dif- 

 fered from ocean water in chlorinity and 

 pH, both items of concern to aquarists. 

 The pH deficiency was easily remedied by 

 heavy aeration of the incoming water, the 

 pH value rising to 8.1 in about 40 minutes. 

 The effects of brackish water on skipjack 

 were unknown, but the slightly low salin- 

 ity of the Kewalo w-ater did not seem 

 likely to be a serious problem. There re- 

 mained to be determined, however, the 

 salinity range to be expected following 

 heavy rains and extensive percolation 

 of pluvial water. Salinity and rainfall 

 data are presented in figure 3, from which 

 it is evident that rain had little diluting 

 effect on the water supply. 



Table 1. — Some properties of Kewalo and Hono- 

 lulu Aquarium ivell water and the nearly ocean 



[AH values as mg./L. except pH] 



1 As CaCOa equivalent. 



Conspicuously absent from table 1 are 

 data on the dissolved oxygen in the well 

 water. Winkler analyses of water direct 

 from the pump gave oxygen values of 0.15 

 to 0.69 ml./L, the mean of 14 samples being 

 0.30 ml./L. This inadequacy was at first 

 remedied by pumping the water over a 

 perforated tray, from which it showered 

 into a large tank containing reef fish. Al- 



