How Must Mining Operations Treat Wastewater Under PERMENLHK 05/2022?

Peraturan Menteri Lingkungan Hidup dan Kehutanan Nomor 5 Tahun 2022 tentang Baku Mutu Air Limbah Bagi Usaha dan/atau Kegiatan Pertambangan Batubara ("PERMENLHK 05/2022") updates wastewater quality standards for Indonesia's coal mining sector. Enacted on March 7, 2022, and recorded in State Gazette No. 366 of 2022, this regulation addresses critical water pollution challenges from coal extraction, processing, and mine site management.

As Indonesia remains one of the world's largest coal producers and exporters (approximately 600 million tonnes annually), coal mining operations generate massive volumes of contaminated wastewater containing suspended solids, heavy metals, acidic drainage, and chemical residues from mineral processing. PERMENLHK 05/2022 establishes enforceable limits on these pollutants to protect Indonesia's watersheds, agricultural lands, and coastal waters.

Scope and Applicability

PERMENLHK 05/2022 applies to all coal mining operations including:

Surface mining operations: Open-pit coal mines that generate runoff containing suspended sediments, chemical additives, and dissolved minerals from exposed coal seams and overburden.

Underground mining operations: Deep mines that produce mine dewatering discharge, often with high acidity and metal concentrations from sulfide mineral oxidation.

Coal processing facilities: Washeries, crushing plants, and beneficiation facilities that use water-intensive processes generating wastewater with coal fines, chemical reagents, and dissolved contaminants.

Mine site management activities: Stockpiles, haul roads, port facilities, and temporary storage areas where rainwater runoff becomes contaminated through contact with coal materials.

The regulation covers both existing operations and new mines, with different implementation timelines. It applies regardless of mine size, ownership structure (state-owned vs private), or end use (domestic consumption vs export).

Key Pollutant Parameters and Limits

PERMENLHK 05/2022 regulates multiple pollutant parameters, with numeric limits established in the regulation's annexes:

pH (Acidity/Alkalinity): Coal mining, particularly when sulfide minerals are present, often generates acidic drainage. The regulation establishes pH ranges (typically 6-9) that wastewater must meet before discharge, protecting aquatic ecosystems from acidification.

Total Suspended Solids (TSS): Mining operations disturb vast land areas, generating sediment-laden runoff. TSS limits (typically 200-400 mg/L depending on discharge location) control erosion and sedimentation impacts on downstream water bodies.

Heavy Metals: Coal deposits often contain trace heavy metals including mercury, lead, cadmium, chromium, zinc, copper, iron, and manganese. The regulation establishes strict limits for each metal, protecting drinking water sources and preventing bioaccumulation in aquatic food chains.

Chemical Oxygen Demand (COD): Organic compounds from coal processing chemicals and decomposing organic matter in mine pits contribute to oxygen depletion in receiving waters. COD limits maintain aquatic ecosystem health.

Oil and Grease: Mining equipment, explosives, and coal dust suppression activities introduce petroleum hydrocarbons. The regulation limits oil and grease concentrations to protect water quality and aquatic life.

Sulfides and Sulfates: Oxidation of pyrite and other sulfide minerals creates sulfuric acid and dissolved sulfates. Limits on these parameters prevent acid mine drainage impacts.

Ammonia: Blasting agents and decomposition processes can generate ammonia, toxic to aquatic organisms. Ammonia limits protect fisheries and aquatic ecosystems.

Numeric limits vary based on discharge location (into rivers, lakes, coastal waters, or constructed wetlands) and receiving water quality characteristics, reflecting the assimilative capacity of different water bodies.

Acid Mine Drainage: Special Requirements

Acid mine drainage (AMD) represents one of coal mining's most persistent environmental challenges. When sulfide-bearing materials are exposed to oxygen and water, chemical and biological oxidation produces sulfuric acid and dissolved heavy metals that can contaminate water resources for decades.

PERMENLHK 05/2022 addresses AMD through several mechanisms:

Preventive measures: The regulation requires mines to implement AMD prevention strategies including:
- Segregation of acid-generating materials from clean overburden
- Rapid revegetation of disturbed areas to limit oxygen and water infiltration
- Underwater storage of sulfide-bearing waste materials
- Application of alkaline materials to neutralize acidity

Treatment requirements: Where AMD occurs, mining operations must implement treatment systems sufficient to meet discharge standards. Acceptable technologies include:
- Lime or limestone neutralization to raise pH and precipitate metals
- Passive treatment wetlands for long-term AMD management
- Active chemical treatment plants for high-volume or high-acidity discharges
- Combination approaches integrating multiple treatment methods

Long-term liability: AMD can persist long after mining ceases. The regulation establishes that mine operators remain responsible for AMD treatment until receiving waters consistently meet quality standards, potentially requiring post-closure monitoring and treatment for decades.

Financial assurance: Environmental permits must include financial guarantees (reclamation bonds) sufficient to fund AMD treatment throughout mine life and post-closure period, preventing abandonment of contaminated sites.

Treatment Technology Requirements

PERMENLHK 05/2022 does not mandate specific treatment technologies, allowing operators flexibility to select approaches appropriate for their site conditions and wastewater characteristics. However, several treatment approaches are commonly employed:

Sedimentation ponds: Multi-stage settlement basins allow suspended solids to settle before discharge, often the first treatment step for mine site runoff.

Chemical precipitation: Addition of lime, limestone, or caustic soda raises pH and precipitates dissolved metals as hydroxides, sulfides, or carbonates that can be filtered or settled.

Constructed wetlands: Engineered wetlands provide passive treatment through physical, chemical, and biological processes, particularly effective for lower-volume AMD.

Filtration systems: Sand filters, fabric filters, or membrane systems remove fine suspended particles and precipitated metal compounds.

Polishing ponds: Final treatment stage providing additional settlement time and allowing microbial processes to reduce residual contaminants before discharge.

Operators must demonstrate through environmental impact assessments that proposed treatment systems can consistently achieve compliance with discharge limits under varying conditions (wet season high flows, dry season low flows, variations in source water quality).

Monitoring and Reporting Requirements

PERMENLHK 05/2022 establishes comprehensive monitoring obligations:

Routine monitoring: Operators must conduct regular wastewater quality monitoring at discharge points, with frequency determined by discharge volume and pollution risk (typically monthly for large operations, quarterly for smaller mines).

Parameters tested: All regulated parameters must be analyzed by certified environmental laboratories using standardized methods, with quality assurance/quality control procedures.

Continuous flow measurement: Major discharge points must have continuous flow meters to quantify total pollutant loads (concentration × volume), enabling assessment of cumulative environmental impacts.

Reporting to authorities: Monitoring results must be reported to environmental authorities (provincial or district environment agencies) within specified timeframes, with electronic submission through online reporting systems.

Public disclosure: Consistent with Indonesia's environmental information transparency requirements, monitoring results may be subject to public disclosure, enabling community oversight.

SPARING integration: Large mining operations may be required to install continuous online monitoring systems (SPARING) under PERMENLHK 93/2018, providing real-time discharge data.

Provincial Authority and Regional Variations

Consistent with environmental federalism principles in Indonesia, PERMENLHK 05/2022 allows provincial governments to establish stricter standards:

Stricter regional standards: Provinces hosting significant coal mining (e.g., Kalimantan Timur, Kalimantan Selatan, Sumatera Selatan) may establish stricter discharge limits based on local water resource priorities and environmental sensitivity.

Scientific assessment requirement: Provincial standards must be based on scientific studies evaluating local environmental conditions, technology availability, and socioeconomic factors, preventing arbitrary restrictions.

Watershed-specific requirements: Provinces may establish watershed-specific standards reflecting pollution carrying capacity (daya tampung beban pencemaran) of particular river systems.

Implementation in permits: Regional standards are incorporated into environmental permits issued by provincial or district authorities, making them legally enforceable.

Integration with Environmental Permitting

PERMENLHK 05/2022's requirements are implemented through Indonesia's environmental permitting system:

AMDAL/UKL-UPL: Mine projects must prepare environmental impact assessments (AMDAL) or environmental management plans (UKL-UPL) analyzing wastewater impacts and proposing management measures, including treatment system design.

Environmental permits: Discharge standards are incorporated as conditions in environmental permits (formerly izin lingkungan, now persetujuan lingkungan under Omnibus Law framework), making violations subject to permit suspension or revocation.

Permit amendments: Existing mines operating under older standards must obtain permit amendments incorporating PERMENLHK 05/2022 limits within specified transition periods.

Mining license conditions: Water quality requirements are also referenced in mining operation licenses (Izin Usaha Pertambangan or IUP), creating dual enforcement pathways through both environmental and mining authorities.

Enforcement and Penalties

Violations of PERMENLHK 05/2022 can trigger multiple enforcement mechanisms:

Administrative sanctions under UU 32/2009 Article 76:
- Written warnings requiring corrective action within specified timeframes
- Operational suspensions until compliance is achieved
- Permit revocations for persistent non-compliance
- Administrative fines (in jurisdictions that have established implementing regulations)

Criminal liability under UU 32/2009 Article 100: Deliberate discharge of wastewater exceeding standards that causes pollution and environmental damage is subject to imprisonment (up to 3 years) and fines (up to Rp 3 billion).

Civil liability under UU 32/2009 Article 87: Strict liability for environmental damage caused by wastewater pollution, obligating polluters to fund restoration regardless of fault, plus potential compensation for economic losses.

License suspension: Mining authorities can suspend IUP or IUPK (special mining business licenses) for environmental violations, halting operations until compliance.

Corporate reputational consequences: Non-compliance affects PROPER ratings, potentially impacting access to finance, supply chain relationships, and export markets increasingly concerned with environmental performance.

Implementation Challenges

Despite comprehensive standards, several implementation challenges persist:

Remote locations: Many coal mines operate in remote areas with limited environmental enforcement presence, reducing detection of violations.

Technical capacity: Smaller mine operators, particularly in artisanal and small-scale sectors, often lack technical expertise to design and operate adequate treatment systems.

Financing constraints: Treatment infrastructure requires significant capital investment, creating barriers particularly for marginal operations and during periods of low coal prices.

Legacy mine sites: Thousands of abandoned or illegally operated mine sites across Indonesia continue generating untreated wastewater, with no responsible party to compel compliance.

Enforcement capacity: Provincial and district environment agencies often lack sufficient personnel, equipment, and budget to conduct regular inspections and monitoring verification at dispersed mine sites.

Competing priorities: Local governments dependent on mining tax revenues may face political pressure to prioritize economic benefits over environmental enforcement.

Conclusion

PERMENLHK 05/2022 establishes a comprehensive framework for controlling water pollution from Indonesia's coal mining sector, addressing critical contaminants including suspended solids, heavy metals, and acid mine drainage. The regulation balances environmental protection with economic realities, providing flexibility in treatment approaches while maintaining enforceable standards.

Effective implementation requires three critical elements: (1) adequate technical and financial support to help operators, particularly smaller mines, achieve compliance; (2) strengthened enforcement capacity at provincial and district levels; and (3) sustained political commitment to environmental protection even when it creates costs for economically significant mining operations.

As Indonesia navigates energy transition and potential long-term decline in coal demand, ensuring proper wastewater management during active mining and effective mine closure planning becomes increasingly important to prevent legacy contamination that would burden future generations.

Legal Source: PERMENLHK 05/2022 at BPK

Related Regulations: UU 32/2009, UU 3/2020 (Mining), PP 22/2021, PERMENLHK 93/2018

Sector: Mining, Environmental Quality, Water Pollution Control

Regulatory Status: Active

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