Police stand by Buyat Bay test results
Abdul Khalik, The Jakarta Post/Jakarta
National Police chief Gen. Da'i Bachtiar said on Friday the police were sticking to their laboratory test results, which showed that Buyat Bay in Minahasa, North Sulawesi, was contaminated with heavy metals, despite a complaint from PT Newmont Minahasa Raya.
Da'i said the tests at the police's forensic lab were conducted by experts from various branches of science who were sworn to conduct their tasks correctly and independently.
"They can present their own findings, which could be different from our results, but as far as the legal process is concerned, only tests done by the police will be used," said Da'i.
He added that the police had made a legal record of every step in the testing process to ensure that their results could be used in court.
"The government has also established a joint team to investigate the contamination. We can talk about the differences in the teams' results later. But for now, we stand by our own findings," said Da'i.
PT Newmont Minahasa Raya, the only mining company disposing its tailings in the bay, questioned on Thursday the results of lab tests conducted by the police, as other tests by different institutions showed that the content of heavy metal in the bay was far below the dangerous level.
Newmont said tests of 390 samples by PT ALS Indonesia showed a mercury level of only 0.055 microgram/Liter (u/L) only, while tests by the Office of the State Minister of the Environment showed a level of 0.059u/L and Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) found 0.005 u/L of mercury.
The three test results all showed mercury levels far below the standard of 1 u/L set by Ministerial Decree No. 51/2004 on seawater pollution standards, Newmont said.
On Wednesday, police said their lab tests showed mercury levels of 5.5 u/L, 4 u/L and 3.9 u/L in samples taken from separate locations in the bay.
Meanwhile, Newmont said police should clarify whether they had measured total mercury content or the dissolved mercury content in the bay, because the first methodology would produce far higher measurements than the latter.
The company said the 1 u/L standard set by the ministerial decree was clearly the level of dissolved mercury, not total mercury.
Coms. Sulistiandriatmoko, the lead investigator of the case, said police were well aware of the different methods and that police had measured the dissolved mercury.
"We are not that stupid. We measured the dissolved mercury, not the total mercury. I think they are just trying to distort the case," he said.
He revealed that while conducting field investigation at the bay, he found the water was discolored 20 meters from the surface because of a concentration of dissolved solids.
"We also discovered that Newmont disposed their tailings at 83 meters from the surface, because they mistakenly assumed that the thermocline was located 50 meters from the surface," Sulistiandriatmoko said.
The thermocline is the region that separates oxygen-rich surface water from oxygen-poor deep water.
He said the company made the erroneous assumption because it conducted the thermocline test only during the dry season, while the thermocline could be located at a deeper level in the rainy season.
According to Sulistiandriatmoko, the Research and Technology Agency later found that the thermocline of Buyat Bay was located 150 meters from the surface.