Sampling the River That Seventeen Million People Drink

The Brantas is East Java's main river and the water supply for around seventeen million people, and it runs past paper mills that discharge into it directly. ECOTON, founded in 2000 as Ecological Observation and Wetlands Conservation, does the sampling that the regulator does not: in a 2023 field study it took a 250-millilitre sample from the Porong tributary and counted roughly 1,449 microplastic particles, about fifteen times the concentration found in other rivers. Its Ekspedisi Sungai Nusantara expedition has since documented 68 Indonesian rivers polluted with sewage and microplastics, building a national picture from riverbank to riverbank. The organisation pairs that evidence with blunt advocacy — including protesting outside consulates over imported plastic scrap that arrives mixed with waste — on the argument that Indonesia should not be absorbing other countries' rubbish while its own rivers go unmeasured.