The Water Quality of the Pasig River in the City of Manila, Philippines: Current Status, Management and Future Recovery

Abstract

Pasig River is an important river in the Metro Manila, Philippines, since it provides food, livelihood and transport to its residents, and connects two major water bodies; Laguna de Bay and Manila Bay. However, it is now considered to be the toilet bowl of Metro Manila due to the large amount of wastes dumped into the river. Even with the efforts of the government to revive the quality of the Pasig River and its tributaries, it continues to deteriorate over time. This paper provides an overview of the current condition of the Pasig River. The existing water management policies were reviewed, and the issues and challenges hindering the improvement of its water quality identified. Moreover, the water qualities of the rivers in Metro Manila were compared to those of the major rivers in South Korea. The current watershed management system practiced by South Korea has been discussed to serve as a guideline for future recovery of the water quality of the rivers in the Philippines.

Water Quality Assessment of Carangan Estero in Ozamiz City, Philippines

“…Comparing the results of the study of Gorme et al (2010) in five urban rivers in Metro Manila, Philippines, the BOD loading is far higher than in Carangan Estero which implies that the water is not as polluted as Metro Manila esteros. However, if this water pollution problem continues without sustainable interventions to reduce contamination, water quality can further deteriorate.…”

“…Site 2 was polluted with massive organic waste, but the rapid stream velocity could carry these materials downstream thus the available nutrient for bacteria was lesser resulting to lower BOD as oxygen demand was lower. Organic wastes increase BOD loading in Metro Manila, Philippines which does not conform to the DENR standard (Orozco & Zafaralla, 2012;Gorme et al, 2010).…”

“…Studies of esteros or rivers in the Philippines showed lower DO readings downstream compared to upstream can be a result of massive discharge of domestic and industrial wastes associated with rapid urbanization (Orozco & Zafaralla, 2012;Flores & Zafaralla, 2012;Gorme et al, 2010). The hypertrophic water condition resulting from organic wastes causes the fish communities in Estero de San Miguel and Estero de Quiapo in Manila to exhibit high evenness but low in dominance and diversity (Orozco & Zafaralla, 2012).…”

“…Waste from domestic sources, agriculture, commercial establishments and industries alter the physicochemical parameters of water in major Philippine esteros, that do not meet the national standards for drinking and for aquaculture (PEMSEA, DENR and LLDA, 2013;Orozco & Zafaralla, 2012;Gorme, et al, 2010;Rañola & Santiago, 2009), despite the efforts of the government to improve water quality. Poor water quality resulting from pollution reduces environmental heterogeneity which leads to low diversity of aquatic life (Teresa et al, 2011).…”

Biogeochemical Analysis in Relation to Water Quality of Wawa Dam, Rizal, Philippines

“…Physicochemical and biological parameters are bioindicators of a healthy ecosystem. Recent studies on physicochemical parameters and nutrient concentrations were done in several river systems and lakes in Metro Manila and other provinces in the Philippines, such as, Pasig River (Gorme, Maniquiz, Song, & Kim, 2010), Manga River (Flores & Zafaralla, 2012), Carangan Estero in Ozamiz City (Enquito et al, 2013), Buhisan and Lahug Rivers in Cebu (Maglangit, Galapate, & Bensig, 2015). Data measured were compared with the DENR Administrative Order 90-34 standard values.…”