Artisanal mining, including some small-scale mining prevalent upstream in the upland town of Kasibu which continues to this day, has resulted in the elevated total suspended solids (TSS) levels in the Didipio River and other rivers downstream. This was according to the Baseline Study of the Major River System and Tributaries of Barangay (Village) Didipio conducted by the Nueva Vizcaya State University (NVSU) in 2004, prior to the entry of large-scale mining, particularly OceanaGold’s Didipio Mine that started operation in 2013. But General Manager David Way of OceanaGold’s Didipio Mine said that from 2014 to 2018, they had seen an improvement of the natural river from using water management technologies while cooperating with the government and artisanal miners.

Domingo, L. C. (2019, January 10). NVizcaya mine continues protection of rivers. The Manila Times, p. 5.