WHILE concerns have been raised earlier over the water safety of the Sapangdaku River, the Mines and Geosciences Bureau (MGB) 7 is assured that the water remains safe.
Based on water samples taken from the river, the multipartite monitoring team (MMT) has found the pH levels of the waters safe.
“The pH levels of the water are safe,” MGB 7 director Roger de Dios told Sun.Star Cebu.
In their initial report, the MGB 7 found the pH levels all within the standards of the Department of Environment and Natural Resources (DENR). The water discharged from the settling pond to the Sigpit Dam had a pH level of 7.87, the water entering the settling pond had a pH level of 8.10, the water from the emergency tailings pond (ETP) had a pH of 7 and the water flowing from the tailings pump house to the ETP had a pH level of 7.95.
This means the water samples taken by MGB were generally neutral. pH is the measurement of acidity or alkalinity. A pH of 7 is neutral, above 7 is alkaline or basic and below 7 is acid.
De Dios said the Carmen Copper Corp.’s (CCC) ETP was almost fixed, but the company has continued operating even without the ETP.
“The company has created a bypass, wherein they are using a different piping system. The tailings from the thickener will then go through a piping system that would lead to the tailings pond,” said de Dios.
‘Not toxic’
The tailings have to go through a thickener that would reduce the water in the tailings before bringing the mine wastes to the tailings pond.
Earlier, CCC resident manager and vice president Roger Cal assured the public that the mine tailings were not toxic and did not use any harmful chemicals as copper concentrate is extracted only through mechanical means.
De Dios confirmed Cal’s claims. “The chemicals that are being used are not toxic. The chemicals only help in allowing the metals to float in the water and stick to the water bubbles,” he added.
Concerns were also raised on the heavy metal content of the tailings, but Cal denied the presence of such elements.
“That’s a common misconception that the tailings have high metal content (as) the metals are extracted to form the concentrate,” explained Cal.
However, the Environmental Management Bureau (EMB) 7 found concentrations of heavy metals in the waters at the mine.
“We found chromium, cadmium and lead, (but) all are at concentration levels of around 0.002” and are within DENR standards, said Marcelino Tabuco, officer-in-charge of the EMB pollution control division.
Levels could only be dangerous if the concentration levels of heavy metals in water are at 0.5 for chromium, 0.05 for cadmium and 0.3 for lead.
“Right now, there is nothing to worry about, because the levels are below our limits for heavy metals,” said Tabuco.
Heavy metals are dangerous because they tend to bioaccumulate, which means their concentration increases every time a person or any biological organism takes in even small amounts of any heavy metal compound. (EPB)
