284 



The Philippine Jozimal of Science 



1914 



Table II. — Bacteriological examinations of the city of Manila water 



supply — Continued. 



Date. 



Colonies. 



Presump- 

 tive test. 



Bacillus 

 coll. 



Amoebae. 



Ciliates. 



Flagel- 

 lates. 



1913. 













■ 



May 7 



254 



4- 





+ 



— 



-U 



8 



496 



+ 



w 



-T 



-r 



+ 



9 



336 



-r 



— 



"T 



■T 



-t- 



10 



906 



-r 



— 



+ 



T- 



+ 



11 



400 



-r 



— 



+ 



+ 



-i- 



12 



656 



-r 



— 





~r 



+ 



15 



1,399 



+ 



- 



+ 



+ 



4- 



16 



399 



-r 



— 



+ 



+ 



+ 



17 



416 



-r 



— 



+ 



~r 



+ 



18 



628 



-r 



- 



-T 



-r 



4- 



19 



1.781 



"T 



— 



-L 



+ 



4- 



20 



1,653 



■r 



- 



-t- 



-r 



-u 



21 



2,925 



~r 





+ 



-r 



+ 



22 



3. 562 ! + 





+ 



T~ 



. 4- 



" BacUltis coli group present. 



As the density of population increases and uninhabited water- 

 sheds become scarcer, the problem of proper protection of water 

 sources grows more complex, and measures have to be taken 

 further to purify the water. At the present time the need of 

 filtration and sterilization is manifest in Manila. A study to 

 determine the method of purification best adapted to conditions 

 in the Philippines is in progress. 



Water supply in Manila. — During the Spanish regime an 

 elaborate water-supply system was installed at Manila, A dam 

 was built across Mariquina River, and the water was pumped 

 from this dam to an underground reservoir having a capacity of 

 about 72,000 cubic meters (19,000,000 U. S. gallons) and was 

 then conducted into the city mains. The water was not filtered 

 or otherwise purified. Mariquina River drained a territory in- 

 habited by approximately 15,000 people, who used the river for 

 bathing, washing clothes, depositing garbage and excreta, as 

 well as for drinking purposes. The banks of the river were 

 thickly inhabited, and the water passed through two large towns 

 and a number of smaller ones. A source of this kind could never 

 be safe. During cholera epidemics, armed guards were stationed 

 along the river banks to protect the river as much as possible 

 from contamination. 



In 1908 a new water system was installed, deriving its supply 

 from Mariquina River at a point above which no people live. 

 A large dam was constructed at Montalban Gorge, and the 

 watershed from which Mariquina River obtains its water supply 



