Greenpeace
Project: Clean Water
Is our water safe?
In 2007, a broad study was carried out by Greenpeace to investigate the quality of various
surface and ground water systems in four countries, including the Philippines. Water from
the systems investigated is known to be abstracted for distribution as drinking water,
generally following purification treatments that include chlorination. Treated waters are
supplied either via piped distribution networks or as bottled water. However, many of
these river and canal systems also receive inputs of potentially contaminated wastewaters
either from point sources and/or diffuse run-off from agricultural land. These and other
sources may also be contributing to contamination of groundwater aquifers in their vicinity,
some of which are used untreated as drinking water.
For most of the areas examined, the primary identified point sources to the surface waters
were wastewater treatment plants (WWTPs) that receive and treat wastewaters from
numerous industrial facilities located on adjacent industrial estates (IE). The facilities on
each industrial estate are involved in a wide range of activities, though for all estates
investigated in this study, a large proportion of enterprises are electronic/electrical
industries.
In two areas in the Philippines (Metro Manila and Bulacan) there are no major wastewater
point sources, though there are likely to be some inputs from domestic and agricultural
sources. A summary of the water systems in the Philippines included in the study is given
in the table below.
Major
wastewater
point source
Metro
Angat-La
Domestic and
Manila
Mesa River
agricultural
system
sources
LagunaSan Juan
Carmelray
Pasig River River
Industrial Park
Basin
WWTP
LagunaDiezmo and
Light Industry’s
Pasig River San Cristobel Science Park
Basin
Rivers
WWTP
Bulacan
Angat River / Domestic and
Bustos Dam
agricultural
sources
Area
River/canal
system
Water abstracted Other drinking
for distribution
waters
to
analyzed
Manila, Caloocan Groundwater
City, Quezon City (direct /treated
& bottled)
Groundwater
Spring water
-
Groundwater
(direct /treated)
Angat water
Groundwater
district,
Tibagan water
district
Table i: Water systems in the Philippines included in the study, with significant point
sources of wastewaters from industrial/municipal wastewater treatment plants (WWTPs),
as well as surface and groundwater sources abstracted for drinking water purposes
Samples of various types of waters were collected and analyzed for a range of metals and
organic chemical contaminants. These included surface waters at or near locations where
water is abstracted for use by water supply utilities, as well as at locations of major
wastewater inputs. Drinking water sourced from certain surface water systems and
supplied via piped networks was also collected, as well as local groundwater that is used
for drinking, either directly or following treatment and supply as bottled water.

A broad study of surface, ground, and drinking water sources in the Philippines
Two of the surface water systems investigated in the Philippines receive inputs of treated
industrial wastewater, though in neither case is water abstracted from the rivers for use as
drinking water. However, some groundwater is abstracted in the vicinity of each site.
At one of these sites, the Light Industry’s Science Park (LISP) 1 in Laguna, river water
collected immediately downstream from wastewater discharges contained a range of
chemical contaminants, particularly organic chemicals. These included a range of
chlorinated solvents, as well as potentially toxic and irritating acrylate esters, the
oestrogenic chemical nonylphenol and the phthalate esters DEHP and DnDP, both of
which are classified in the European Union as toxic to the human reproduction system.
Some of these same chlorinated solvents (di-, tri- and tetrachloroethene) were also found
in water drawn from a groundwater source nearby, despite the fact that this water was
sampled after it had already been treated and distributed through a piped network. One of
two other groundwater samples collected in the vicinity of LISP 1 contained copper at a
level slightly elevated above background, though far below national drinking water limits.
The source of elevated copper is not clear.
For the other industrial estate in the Laguna area, the Carmelray Industrial Park II, very
few industrial chemicals were found in wastewater discharged from the WWTP. No
organic chemicals were found in the two groundwater samples from this area. However,
one sample from a well within the Industrial Park contained zinc at a level far higher than
typical background levels, though significantly below the national maximum drinking water
level. The exact source of zinc to this groundwater is not clear, though once again the
possibility that activities within the estate may be causing localized contamination of the
groundwater needs further investigation.
For the other two water systems that do not receive wastewater discharges from large
WWTPs, namely Metro Manila and Bulacan, no significant chemical contamination was
identified at locations where water is known to be abstracted for use as raw water for
drinking water supply. Nevertheless, volatile organic chemicals and high levels of metals
were found in some samples of tap water sourced from these systems, and also in
samples of groundwater from the two areas. In Metro Manila, for example, one of three
tap water samples contained not only trihalomethanes derived as byproducts of chlorine
disinfection, but also traces of the chlorinated solvents trichloroethene and
dichloropropene which are likely to have arisen from industrial sources. None of these
samples contained high levels of metals. In the Bulacan area, one of two tap water
samples contained trihalomethanes as well as a relatively high level of zinc (approximately
half the national maximum drinking water level). These chemicals were not found in the
surface waters used to supply raw water for treatment for drinking water supplies.
A groundwater sample from close to the Metro Manila surface water system also
contained trihalomethanes and an elevated zinc level, which might possibly be related to
the nearby Payatas landfill. Bottled water purchased in Metro Manila contained higher
than usual levels of zinc and, once again, traces of the more unusual contaminant
bis(chlorophenyl)sulphone. However, no chemical contamination was found in the
groundwater sample from the Bulacan area.
In short, in many of the cases in which contaminants have been found in treated tap or
bottled water, the river systems from which the raw water is drawn for these supplies do
not appear to be the source of these contaminants. Instead, these may arise from
materials used in the piping network (e.g. zinc, and possibly bis(chlorophenyl)sulphone)
and water treatment processes employed (trihalomenthanes). At some locations,
however, the results do indicate localized contamination of groundwater aquifers,
especially where sources are located within or close to industrial estates. Further and
more detailed investigations would be necessary if the sources of this contamination are to
be determined.