Water supply for the city comes from two sources: Angat Dam, a surface water with a discharge capacity of 18,000 lps and ground water, deep wells having discharge capacity of 460 lps. At present, two PTF deep wells, named after the Presidential Task Force who undertook the installation project, augment the water supply in the vicinities of Brgy. Plainview and Brgy. Barangka Drive.

In addition, around 60 public deep wells supply households lacking connections from the water distribution system, while 18 units of deep wells serve the industrial sector.

Generally, the city is supplied by the Manila Water Company Inc. (MWCI), a private waterworks system whose network (see Table 6.03) covers eight local government units in the eastern part of Metro Manila, and derives water from major water shed areas in the provinces of Bulacan, Rizal and Quezon (Table 6.04). The network operates six pumping stations with drawing capacity ranging from 141 to 268 million liters per day. Water is then distributed through pipelines of different materials (RC, Steel, Cast Iron, Asbestos and PVC) with diameters ranging from 50mm to 2,200 mm. Main distribution pipes in the city measure about 300 to 500 mm diameters (Map 59).

Table 6.03
Description of Water System

Table 6.04
Major Sources of Water

Census 2000 reveals that only 32,645 households or 54.70% of the total number of households in the city have individual water connection from distribution system, while 32.38% still rely on dug wells for water supply. (Table 6.05a & Table 6.05b).

Although the water from the main distribution system is maintained safe for drinking, more and more households are getting cautious so as to use this water mostly for laundry and bathing purposes only. Drinking water is more often bought from water filter and refilling stations and this is evidenced by proliferation of such stations along both major and interior roads in the city.

MWCI, on the other hand, reports that status of water service connection in Mandaluyong is now 98%.

The Sanitation Division of the City Health Office conducts regular monitoring of water sources on various places such as schools and restaurants, as well as all water refilling stations operating within the city.