Waste treatment at major oil and mining firms

Sudibyo M. Wiradji, The Jakarta Post/Jakarta

Waste is inseparable from industrial activities, including those conducted by natural resource-based businesses, such as oil and gas producers and mining companies in remote areas in Indonesia.

Imagine what would happen to the environment and communities in the vicinity if the huge volume of waste was not properly managed.

Polluted waterways are a serious threat not only to the ecosystem, but also to the livelihood of communities in the vicinity and thus sustainable development, a major concern of the United Nations, could be placed in great danger.

Aware of the importance of sustainable development, major natural resource-based firms have shown a strong commitment to managing their waste properly as part of their efforts to preserve the environment for future generations.

French Total E&P Indonesie, for example, which operates the Mahakam oil field in East Kalimantan province, has a strict environmental policy, especially in regards to waste.

The water resulting from oil and gas production activities is treated in the company's Oily Water Treatment Units (OWTU). Produced water treated in these units is clean enough to discharge into the sea, which is in compliance with local and central government requirements.

Through its OWTU, the produced water has reduced oil content at only 25 mg/l, far below the maximum allowable oil content required by the government. "With oil content of 25 mg/l, the water is safe for the environment," said the company's environmental department head, Suripno.

Total's operation sites cover an area of 2,000 hectares, with seven oil and gas fields, and 500 production wells in remote areas in East Kalimantan, including Handil, Bekapai, Peciko, Tambora and Tunu.

Total has introduced the Industrial Pilot of Oily Waste Composting (IPOC), a treatment unit to process contaminated soils and cuttings biologically by applying the windrow and biopile method. This efficient and economical method can also be used to treat contaminated soils resulting from accidents like oil spills on land.

As in other companies, hazardous waste that it is unable to treat at its own treatment plants -- such as used batteries and expired chemicals -- is stored in the company's temporary storage area before being sent to the authorized toxic (B3) waste landfill facility at PT Pamunah Limbah Industri (PPLI) in Cileungsi, West Java.

Meanwhile, Caltex Pacific Indonesia (CPI) boasts using applicable, economical and environmentally friendly technology to handle its industrial waste, especially oily waste, through Slurry Fracture Injection (SFI) because the technology has proven effective.

Caltex, a subsidiary of U.S.- based Chevron Texaco, operates in Riau province, with 107 active oil fields and 6,569 production wells. The company's operation site covers an area of 25,500 square kilometers.

With SFI technology, the oily waste is injected underground far below the production zone. The oily water dumped underground is safe for the environment because the characteristic of underground water is similar to that of the waste.

"However, Caltex continuously conducts strict monitoring of the behavior of the waste in the formation by, for instance, using a tilt meter, to prevent any unexpected impact and to ensure that the waste won't be detrimental to the environment," said Harry Bustaman, Caltex's manager for corporate communication.

The company also uses a well to monitor the real condition of soil water underground in a nearby waste disposal area.

Like Caltex, Newmont Nusa Tenggara (NTT), which operates a massive gold and copper mine in Batu Hijau, Sumbawa, West Nusa Tenggara, also has a long-term environmental monitoring program to evaluate potential impacts of the company's operations.

Newmont uses the Sub-Sea Tailings Placement (STP) system to dispose of its mineral waste. Based on environmental impact assessment (AMDAL) analysis for its Batu Hijau site, the disposal of tailings in the sea at a depth of around 3,000 meters in the bottom of its Senunu canyon waste dumping ground does not damage the marine ecosystem, sea habitats or marine animals.

According to one study, the system is effective because there is little oxygen or biological activity in the deep sea and that minimizes the impact on the environment. "If the tailings were dumped on the land, then it would impact over 1,900 hectares of productive jungle and agricultural land," said NTT's manager of environmental affairs, Grantley Batterham.

To ensure that the tailings it produces are not detrimental to the environment, marine life in particular, the company, by means of on-shore and offshore pipelines, releases the tailings at a depth of 112 meters at the head of the Senunu submarine dumping site. "This is well below the biologically productive surface waters," he said.

Based on a toxicity study by an independent party, the tailings are nontoxic and therefore are not detrimental to marine species, including commercial fish, he said.

The system is monitored extensively to ensure the system functions as designed to minimize the potential for environmental impacts outside of what was anticipated in the environmental impact analysis.

Unlike Newmont, gold and copper producer PT Freeport Indonesia, which operates a massive gold and copper mine in Timika, Papua, uses rivers to transport its tailings to the designated area in the lowlands and coastal zone, called the Modified Ajkwa Deposition Area, which is an engineered, managed system for the deposition and control of tailings.

Independent environmental audits of Freeport Indonesia concluded that the company's tailings management plan represents the best alternative, given the applicable geotechnical, topographic, climatological, seismic and water quality conditions, according to the company's senior manager for corporate communication, Siddharta Moersjid.

Water in Ajkwa River, which transports the tailings from Freeport Indonesia's mine in the highlands to the lowlands deposition area, meets Indonesian and U.S. environmental protection agencies' drinking water standards for dissolved metals, he said. "However, we continually evaluate and update the tailings management plan to minimize potential risk," he added.

Recyclable materials such as aluminum, scrap metal and used batteries are collected and stored in a temporary storage area for subsequent disposal in accordance with the requirements of the Indonesian government, Siddharta said.

Under the government-approved overburden management plant, Freeport Indonesia places waste rock or overburden in a managed area in the Grasberg open pit.

Coal producer PT Arutmin Indonesia, which operates in three concession areas -- in Satui, Batulicin and Senakin in South Kalimantan -- produces waste in the form of acid water flowing from piles of soil resulting from digging activities.

Arutmin said that to mitigate the potential environmental impact from the mining activities on the surrounding area, the company utilized a drainage system in which acid water is neutralized with lime in settling ponds.

"We use about eight tons of lime per ton to neutralize the water or minimize the level of acidity," said company spokesman Zainuddin Lubis, adding that unless acid water was treated properly, it would be detrimental to the environment.

Another coal producer, Kaltim Prima Coal (KPC), which also operates in East Kalimantan, has started reusing its waste as an alternative resource. For example, the company uses used tires to stop erosion in rehabilitated areas.