Benguet, Philippines
City population: 137404
Duration: 2020 – 2020
Implementation status: In piloting stage
Scale: Sub-microscale: Street scale (including buildings)
Project area: unknown
Type of area: Other
Last updated: June 2024

Balili River, situated in the province of Benguet, is among the many urban rivers in the Philippines that suffer from severe pollution due to various human activities. Indiscriminate dumping of waste in almost all of its 23 tributaries is a significant contributor to the pollution. Despite this, the river remains a critical source of irrigation for farmers in La Trinidad who primarily grow strawberry and salad crops in the valley. However, the use of contaminated water from the river poses a direct threat to the food safety of consumers of these crops. Moreover, during the summer, the black water of the Balili River is a constant eyesore in the community. To address these environmental concerns, a pilot study was conducted aimed at exploring treatment options for the polluted water in Balili River. The study focused on assessing the use of local plants to restore biodiversity, conserve wildlife habitats, and test the phytoremediation potential of local macrophytes. The pilot area was established within the Organic Farm of Benguet State University near the main stream of the Balili river. The study set up two types of constructed wetlands (CW), a surface flow CW for floating plants and a horizontal subsurface flow CW for emergent plants. The results of the pilot study suggest that constructed wetlands could be an effective solution for cleaning up the Balili River. The implementation of constructed wetlands in Balili River can not only improve the water quality but also benefit the local community and ecosystem. [1,2]

Balili River Constructed Wetland
Notes: (A) water pump to bring wastewater into the phytoremediation setup; (B) primary treatment component of compost filter and settling tank; (C) constructed wetlands, one each for every selected aquatic macrophyte
https://www.searca.org/pubs/books?pid=472

Overview

Nature-based solution

  • Blue infrastructure
  • Rivers/streams/canals/estuaries
  • In-land wetlands, peatlands, swamps, and moors

Key challenges

  • Green space, habitats and biodiversity (SDG 15)
  • Habitat and biodiversity restoration
  • Water management (SDG 6)
  • Improvements to water quality
  • Economic development and employment (SDG 8)
  • Economic development: agriculture
  • Tourism support

Focus

Knowledge creation and awareness raising

Project objectives

The pilot project had three main objectives: 1. To identify ecological treatment options for the polluted water in Balili River that can help clean the irrigation water of local crops in the valley to improve food safety and restore the river’s ecology, particularly for ecotourism and aesthetic purposes. 2. To assess the suitability of local plants for use in the constructed wetland in terms of restoring biodiversity and conserving wildlife habitats. 3. To test the phytoremediation potential of local macrophytes [1,2].

Implementation activities

The study conducted an inventory of aquatic macrophytes in Balili River to identify potential plants for phytoremediation, using dominance, high biomass, and deep root systems as selection criteria. From this inventory, three emergent plants - Amaranthus spinosus, Eleusine indica, and Pennisetum purpureum - were selected for evaluation, along with Eichhornia crassipes, a free-floating plant that is locally available but not found in the Balili River. To assess their phytoremediation potential, the study utilized two types of constructed wetlands (CWs): a surface flow CW for floating plants and a horizontal subsurface flow CW for emergent plants. The pilot setup was established within the Organic Farm of Benguet State University, near the mainstream of the river, allowing for convenient access to wastewater for treatment. Water quality parameters were then measured to evaluate the effectiveness of the pilot setups. Results of the study showed that local dominant aquatic macrophytes are promising phytoremediators. Overall, the study found that Pennisetum purpureum exhibited the highest pollution reduction efficiency among the evaluated macrophytes. The results showed a significant improvement in the wastewater quality in almost all water assessment parameters. The values of total suspended solids, dissolved oxygen, nitrate, and mercury were notably reduced and met the minimum water quality standard. Biological oxygen demand, phosphate, and lead remained slightly above the standard, but total and fecal coliform did not pass the water quality standard for class A water. [1,2] The study's findings suggest that the creation of a constructed wetland area, either as a full-scale or seasonal wetland, covering 1000 square meters, could be a potential solution for improving water quality in the city. [2]

Biodiversity conservation or restoration-focused activities

Biodiversity restoration:

  • Rehabilitate and restore damaged or destroyed ecosystems
  • Restore species (native, endangered, or unspecified)
  • Other

Main beneficiaries

  • Local government/Municipality
  • Citizens or community groups
  • Food producers and cultivators (i.e. farmers, gardeners)

Governance

Management set-up

  • Led by non-government actors

Type of initiating organisation

  • Researchers/university

Participatory approaches/ community involvement

  • Unknown

Details on the roles of the organisations involved in the project

The pilot study was led by two government universities - the University of the Philippines and Benguet State University [1,2].The study was part of the PhD dissertation titled, “Phytoremediation Performance of Aquatic Macrophytes of Balili River in A Pilot-Scale Constructed Wetland”. Bulacan State University was providing a graduate scholarship and the Southeast Asian Regional Center for Graduate Study and Research in Agriculture (SEARCA) awarded the dissertation grant [2]. According to the proponents of the study, the city is open to adopting the design of the wetlands when funds become available [3]

Project implemented in response to ...

... an EU policy or strategy? Unknown
... a national policy or strategy? Unknown
... a local policy or strategy? Unknown

Financing

Total cost

Unknown

Source(s) of funding

  • Research organisation / University
  • Other

Type of funding

  • Direct funding (grants, subsidies, or self-financed projects by private entities)

Non-financial contribution

Unknown

Impacts and Monitoring

Environmental impacts

  • Water management and blue areas
  • Improved water quality
  • Enhanced protection and restoration of freshwater ecosystems

Economic impacts

  • More sustainable tourism

Socio-cultural impacts

  • Education
  • Increased support for education and scientific research
  • Increased awareness of NBS and their benefits

Type of reported impacts

Expected impacts, Achieved impacts

Presence of formal monitoring system

Unknown

Presence of indicators used in reporting

Yes

Presence of monitoring/ evaluation reports

No evidence in public records

Availability of a web-based monitoring tool

No evidence in public records

References

[1] Napaldet, J.T. and Buot, I.E. (2019). Treatment of Balili River in Benguet, Philippines with constructed wetland planted with dominant local macrophytes. International Journal of Phytoremediation, 21(14), Source link. Source link
[2] Napaldet, J. and Buot Jr., I. (2020). Methodologies Supportive of Sustainable Development in Agriculture and Natural Resources Management: Selected Cases in Southeast Asia - SEARCA. [online] Source link. Available at: Source link [Accessed 18 Feb. 2023].
[3] Napaldet, J. and Buot Jr., I. (2023). Information provided by the project developers, 24 February
Information about this nature-based solution was collected as part of the "NBS 2022" UNA Asian extension project funded by the Asia-Europe Foundation.