Mercury contamination in groundwater from artisanal and small scale gold mining activities: a case study of Southern Lombok Coast, West Nusa Tenggara Province

Abstract

Artisanal and small scale gold mining (ASGM) activities usually use the amalgamation process with mercury to extract the gold. The waste of amalgamation is disposed of in a pond or discharged directly into the river. Most of the tailing ponds are located close to the community wells due to water supply purposes for the amalgamation activity. The amalgamation activity could cause mercury pollution to the community well. This study is aimed to determine the mercury concentration in the groundwater in Southern Lombok Coast. The method used during the study were observation and laboratory testing for mercury concentration. An observation activity had been completed at three villages, namely West Sekotong, Pelangan, and Batu Putih, to identify the process of amalgamation and tailings disposal. Ten community wells associated with the amalgamation process were taken as the sample locations for mercury laboratory testing. It was found that the mercury concentration at the nine location samples was below 0.06 µg/l, and only one location sample (sample code P2) was detected with mercury concentration more than 0.06 µg/l. The results indicated that most of the community wells water met with the government standard (Hg = 0.005 mg/L) as stipulated in government regulation No. 82 of 2001.