70 "^fi^ Philippine Journal of Science i»i6 



From a chemical point of view, the water is potable, and since 

 it comes from a sparsely settled watershed, which could be 

 closed to settlement and guarded against trespass, it can doubt- 

 less be kept uncontaminated. The chemical analysis of the 

 Tigon River water is as follows: 



Table III. — Chemical analysis of the Tigon River water. 



Physical characteristics Normal. 



Turbidity Nil. 



Color Nil. 



Total solids 390 



Fixed 290 



Volatile 100 



Organic matter Trace. 



Alkalinity as CaCO. 50 



Iron (Fe) 0.7 



Magnesium (Mg) Little. 



Normal carbonates as NaaCOj Nil. 



Bicarbonates as CaCOi 50 



Sulphates as SOi 54 



Chlorides (CI) 16 



Total hardness as CaCOi 140 



Estimated encrustants 140 



GUIMARAS ISLAND 



Guimaras Island is well supplied with water. In the coralline 

 limestone formations near the coast there are many springs 

 which have excellent local reputations; farther inland and up- 

 land there are streams which have an apparent abundance of 

 clear soft water. During the Spanish regime, the waters from 

 various springs were brought into great stone baths, some of 

 which still exist. 



The single attempt to drill an artesian well on Guimaras 

 proved a failure. Although a depth of over 200 meters was 

 attained, no potable water was encountered in any appreciable 

 quantities. 



Table IV shows the analyses of typical water supplies. 



The "probable encrustants" were determined in accordance 

 with the formula given by Dole.''- The "classification for boiler 

 use" is more or less arbitrary. 



Chemically these waters appear to be suitable for the Iloilo 

 supply. Guimaras Island is so sparsely populated that it should 

 be very easy to prevent the contamination of any of the sources 

 listed. 



• Water Suppl. & Irrig. Papers, U. S. Geol. Surv. (1910), No. 254, 232. 



