Standing on the banks of the Maros River in Sulawesi’s Maros Baru district, students from Universitas Hasanuddin can witness the impact their education is having. A trash trap the students and their lecturers conceptualised, designed, and built hauls some 2kg of plastic waste out of the river each day, ensuring that the debris never meets the sea.

It is one of three trash traps that have been installed as part of the Clean UnHas River Bound (CURB) project, an Alliance-supported initiative. The one on the Maros River was installed in March 2023, and a second one went into the Kariango River in Pinrang Regency in June. A third was installed in the Cenrana River in Bone Regency in September.

But the initiative goes back further, to 2020, when the idea was seeded as part of the university’s Student Study Service program, or Kuliah Kerja Nyata (KKN). As part of their higher education, the students had to spearhead community service initiatives, and this group, comprising 350 engineering students, wanted to help clean up the rivers which feed into the Makassar and Bone Straits.

The students had to first lay the groundwork, and get both funding and buy-in from local regencies and districts. Team members then put their engineering knowledge towards designing and developing the trash traps with stability, durability and effectiveness in mind. The traps could span not more than a third of the river so other river-based activities, like fishing, which the local communities depended on, could continue.

Before installing the trap, the UnHas team also needed to put in place a waste processing unit where the collected waste could be transferred, stored, segregated, washed and then either composted or sent for recycling. They then had to train local employees on the best practices to monitor, maintain and handle the traps, taking into account emptying cadence, river tides, and other guidelines to ensure waste does not flow back into the river.

In order to better engage with the communities in the three regencies, the students also spent “internships” living alongside them. This enabled the students to pass on knowledge on the use and maintenance of the traps and sorting facilities, and to educate the communities on the proper use and disposal of plastic waste, addressing the problem at source. Some 6,700 people living in the area will benefit from the enhanced waste management services.

Buoyed by the trap’s efficacy and learnings from the project, the Regent of Maros, Chaidir Syam, has said the system will be replicated elsewhere, including in irrigation canals.

According to the World Bank, about 4.9 million tonnes of the 7.8 million tonnes of plastic waste that Indonesia generates annually is mismanaged. Rivers carry and discharge some 83% of the plastic that ends up in the marine environment.

This is the Alliance’s first sponsored trash trap initiative.