What the BOD Discharge Limit in Indonesia Actually Is in 2026
In Indonesia, the BOD5 discharge limit for industrial wastewater is 50 mg/L under PP No. 22 Tahun 2021 Lampiran VI, with 30 mg/L required for discharges into higher-quality Class I and II water bodies and 100 mg/L permitted for select domestic and certain agro-industrial categories. Compliance is enforced through Permen LHK P.68/2016 sector rules and provincial governor decrees (Pergub), and is typically met with a treatment train combining equalization, biological A/O or MBR, and DAF polishing.
BOD5 refers to the 5-day biochemical oxygen demand test at 20 °C, standardized in Indonesia as SNI 6989.72:2009 and equivalent to APHA 5210 B. This is the parameter regulators cite, not BOD20 (which is roughly 1.4–1.7× higher) or COD (which runs typically 2.0–2.5× BOD5 for biodegradable industrial streams). When a permit application asks for "BOD" without a subscript, assume BOD5.
The 50 mg/L ceiling applies to most process wastewater discharged to surface water under PP 22/2021 Lampiran VI. The 30 mg/L tighter tier triggers when the receiving water body is classified as Kelas I (drinking water source with simple treatment) or Kelas II (aquaculture, recreation) per PP 22/2021 Lampiran VII. The 100 mg/L tier covers domestic effluent from non-urban areas and several agro-industrial sub-categories, including smallholder palm oil mills below 30 ton FFB/day throughput. PP 22/2021 replaced PP 82/2001 and reclassified 12 industrial categories — a fact that invalidates any compliance memo built on the 2001 tables. For oil and grease parameters that almost always ride alongside BOD5 in the same permit, see the oil and grease discharge limit in Indonesia reference guide.
The Regulatory Pyramid: PP 22, Permen LHK, and Provincial Pergub
PP 22/2021 is the binding national ceiling (Baku Mutu Air Limbah) across all sectors; the Permen LHK sectoral decrees set category-specific limits; the Pergub tightens both at the receiving water body. The tier you are bound by is the strictest of the three that applies to your outfall.
At the top of the pyramid sits PP No. 22 Tahun 2021 (Lampiran VI), which sets the nationwide maximum BOD5 of 50 mg/L for industrial wastewater discharged to surface water and 100 mg/L for specified domestic categories. Mid-tier sectoral decrees add parameters and tighten limits within their scope: Permen LHK P.68/Menlhk/Setjen/Kum.1/8/2016 governs domestic wastewater, Permen LHK P.16/2019 governs palm oil (CPO), and similar decrees exist for textile, food, and pharmaceutical categories. The bottom tier comprises provincial governor decrees (Pergub) — for example, Pergub DKI Jakarta No. 69/2013 and Pergub Jawa Tengah No. 13/2020 — which often impose limits 20–40% stricter than the national ceiling on plants discharging into priority watersheds.
For 2026 enforcement, KLHK has shifted from self-reported compliance to per-discharger continuous monitoring on PROPER-rated facilities (PROPER KLHK ratings run Gold, Green, Blue, Red, Black). Sampling frequency for self-monitoring under PP 22/2021 is at minimum monthly for BOD5, COD, TSS, pH, and flow, with KLHK conducting unannounced ad-hoc sampling that has resulted in 12% of audited textile plants in West Java receiving Red ratings in 2025 (KLHK PROPER public record, 2025). Provincial environmental offices (DLH Provinsi) handle the day-to-day outfall inspection; KLHK handles the legal case if a Pergub or PP 22 violation triggers prosecution.
BOD5 Limits by Industry Sector (Lampiran VI Reference Table)
PP 22/2021 Lampiran VI gives the national ceiling; sectoral Permen LHK and Pergub override it where stricter. The table below consolidates the binding BOD5 number for the eight sectors most commonly cited in Indonesian permit applications. Always confirm against the current Pergub for the receiving water body class.
| Sector | Binding BOD5 (mg/L) | COD (mg/L) | Key co-limits | Primary regulation |
|---|---|---|---|---|
| Palm oil / CPO mill | 100 (national); 50 (West Sumatra Pergub) | 350 | Oil & grease 25 mg/L; pH 6–9; Total N 50 mg/L | Permen LHK P.16/2019; PP 22/2021 Lampiran VI |
| Textile / dyeing | 50 | 150 | Color < Pt-Co 100; sulfide 0.5 mg/L; Cr(VI) 0.1 mg/L | PP 22/2021 Lampiran VI; Pergub Jawa Barat 12/2018 |
| Food & beverage / dairy | 50 | 100 | Oil & grease 15 mg/L; pH 6–9; NH3-N 5 mg/L | PP 22/2021 Lampiran VI |
| Tannery / leather | 50 | 150 | Total Cr 0.5 mg/L; sulfide 0.5 mg/L; TDS 2,000 mg/L | PP 22/2021 Lampiran VI; sectoral Permen LHK guidance |
| Pharmaceutical / antibiotic | 50 | 150 | Residual antibiotic ecotoxicity clauses; pH 6–9 | PP 22/2021 Lampiran VI |
| Pulp & paper | 100 (national); 50 (Riau, Jambi Pergub) | 350 | AOX 1 mg/L; color < Pt-Co 200; TSS 100 mg/L | PP 22/2021 Lampiran VI; Pergub Riau 19/2020 |
| Domestic / commercial | 30 (DKI Jakarta); 100 (rural districts) | 50 (DKI); 100 (rural) | Coliform < 3,000 MPN/100 mL; TSS 30 mg/L | Permen LHK P.68/2016; Pergub DKI 69/2013 |
| Metal finishing / electroplating | 50 | 150 | Total Cr 0.5 mg/L; heavy metals per PP 22/2021 Table 1 | PP 22/2021 Lampiran VI |
Two practical notes. First, the binding number is always the strictest applicable tier — if your outfall enters a Class II river, the 30 mg/L domestic limit can override a 50 mg/L industrial ceiling if the Pergub lists you as a domestic-equivalent discharge. Second, the chrome and sulfide numbers in the tannery row will fail the permit long before BOD5 does; design the plant around them.
Treatment Train Sizing: Hitting 50 mg/L BOD5 from Real Influent
Indonesian industrial BOD5 influent typically lands between 800 and 5,000 mg/L across most sectors: textile 1,500–2,500 mg/L, food and beverage 1,000–3,000 mg/L, palm oil 5,000–25,000 mg/L, pharmaceutical 500–2,000 mg/L. Designing for 50 mg/L effluent from these strengths is a 95–99% removal problem, well within conventional activated sludge, but the failure mode is rarely soluble BOD — it is suspended solids and colloidal COD that escape the clarifier.
For a conventional A/O train targeting 50 mg/L, design to F/M 0.1–0.3 kg BOD/kg MLSS·d, MLSS 3,000–4,000 mg/L, HRT 8–12 h in the aerobic zone, and DO 1.5–2.0 mg/L. SRT should be 15–25 days to keep nitrification stable. An MBR upgrade raises MLSS to 8,000–12,000 mg/L, doubles the allowable F/M without washout, halves the footprint by removing the clarifier, and holds BOD5 under 30 mg/L even with 2× shock loading (Zhongsheng field data, 2025-2026 across 14 Indonesian textile and food plants).
Two design factors specific to Indonesia. Tropical wastewater runs at 28–32 °C, which increases biological reaction rates by roughly 30% versus temperate 15 °C design — meaning you must derate aeration or you waste blower power and risk floc breakup. And in 80% of the failure cases I have seen in Sumatra and Java, BOD5 breaches trace to residual TSS from a poorly sized clarifier, not to soluble BOD — which is why a DAF polishing unit downstream of the biological step is the most reliable insurance. For DAF sizing on high-strength streams like sugar mill effluent, see the DAF sizing for sugar mill effluent reference.
Process Flow for an Indonesian Industrial Plant (Example)
The flow below takes a 500 m³/d textile plant with raw BOD5 of 2,000 mg/L to a compliant 30 mg/L BOD5, 50 mg/L TSS outfall into a Class II receiving water. Each stage is sized to the loading it actually receives, not the textbook value.
- Rotary bar screen, 6 mm gap. Removes plastics, fibrous solids, and lint that would rag up downstream pumps. This is the first piece of equipment on a textile P&ID, installed via a rotary mechanical bar screen with automatic rake.
- Equalization tank, HRT 8 h, aerated. Buffers BOD swings (textile batch dyeing causes 3–5× spikes), evens temperature to 30 °C, and lets pH neutralize before biology. Typical 167 m³ for the 500 m³/d case.
- A/O biological reactor, HRT 10 h, MLSS 4,000 mg/L, DO 2 mg/L aerobic. Achieves ~95% BOD removal and partial denitrification. Aeration demand ~2.5 kg O2/kg BOD removed. An MBR bioreactor system replaces the clarifier and doubles MLSS if footprint is constrained.
- DAF polishing, hydraulic retention 20 min, air-to-solid ratio 0.04. Lifts residual TSS to under 30 mg/L and shaves the last 10–20 mg/L of BOD5 by removing the colloidal fraction. A DAF polishing unit is sized to 20% of forward flow when run on thickened return.
- Chlorine dioxide disinfection, contact 30 min. Achieves coliform < 3,000 MPN/100 mL, the most common Pergub requirement. Dosed via a chlorine dioxide generator at 1.5–2.0 mg/L residual. Coagulant dose upstream of DAF is set with an automatic coagulant dosing skid to keep polymer consumption within 2–5 mg/L.
The integrated above-ground package, particularly the WSZ underground integrated unit, is often the right answer for small domestic plus pre-treated industrial streams where civil work costs dominate.
Compliance Risk and CAPEX/OPEX Reality in 2026
Non-compliance under PP 22/2021 progresses through three stages: written warning (60 days to cure), partial permit suspension, then revocation under Articles 260–264. If the violation causes environmental damage, criminal liability under UU 32/2009 Article 99 carries up to 10 years imprisonment and a Rp 10 billion category fine, with the highest-profile 2024 case resulting in a Rp 8.5 billion fine against a West Java textile discharger (per KLHK enforcement record, 2024-11).
For a 500 m³/d BOD-compliance retrofit in 2026, the realistic CAPEX range is USD 200,000–800,000 depending on influent strength, discharge target, and whether the existing tankage is reused. OPEX runs USD 0.25–0.60 per m³, dominated by aeration electricity (40–55% of OPEX) and sludge hauling (15–25%). Plants that skip the DAF and rely on a clarifier alone typically see 30–40% higher OPEX from polymer over-dose and sludge dewatering cost (Zhongsheng OPEX benchmarking, 2025-2026). KLHK's 2024–2026 enforcement emphasis is concentrated on textile facilities in West Java and palm oil mills in Riau, North Sumatra, and South Sumatra; the count of PROPER Red ratings in those two sectors rose 18% year-on-year through Q3 2025.
Frequently Asked Questions
What is the BOD5 discharge limit for industry in Indonesia in 2026? PP 22/2021 Lampiran VI sets 50 mg/L for most industries, 30 mg/L for discharges into Class I and II waters, and 100 mg/L for specified domestic and certain agro-industrial categories. Provincial Pergub can override these to stricter values.
How is BOD5 measured for Indonesian permit compliance? Under SNI 6989.72:2009, the Indonesian national equivalent of APHA Standard Methods 5210 B, with a 5-day incubation at 20 °C. Results are reported in mg O2/L.
What is the most space-efficient treatment train to hit 30 mg/L BOD5 for a tropical industrial plant? MBR (membrane bioreactor) followed by DAF polishing. The MBR runs at MLSS 8,000–12,000 mg/L with no clarifier, and the DAF catches the residual TSS that usually causes the breach.
Can a provincial governor decree set stricter BOD limits than PP 22/2021? Yes. Pergub DKI 69/2013 sets 30 mg/L for domestic outfalls in central Jakarta; Pergub Jawa Tengah 13/2020 sets 50 mg/L for industries discharging into the upper Bengawan Solo watershed. Always check the local Pergub before finalizing the design basis.
How often must BOD5 be tested for compliance? Monthly self-monitoring at minimum, with results submitted via the KLHK online reporting portal. KLHK conducts unannounced sampling, and PROPER ratings are updated twice yearly based on the combined self-reported and audit data.
