On 2026-08-18, Delhi's Anti-Corruption Branch arrested six people in a case tied to the Delhi Jal Board's sewage treatment plant upgrade programme, while in Tiruchi, a 100 MLD sewage treatment plant at Panjapur moved closer to handover thehindu.com thehindu.com. The day's news split cleanly: one large municipal upgrade programme entangled in a corruption investigation, and a second municipal upgrade programme pressing through to mechanical completion against a different kind of headwind.
Key takeaways
- Delhi ACB arrested six people on 2026-08-18 in a case over Delhi Jal Board sewage treatment plant upgrade tenders, with the action taken on the night of 2026-08-18 rediff.com.
- The Delhi Jal Board programme covers the augmentation and upgradation of 10 sewage treatment plants across Delhi, with the tenders at issue estimated at around Rs 1,943 crore indiatoday.intoday.in.
- The tender is the subject of a corruption investigation rediff.com.
- Tiruchi Corporation's 100 MLD sewage treatment plant at Panjapur is progressing and is expected to be completed by August thehindu.com.
Enforcement & Penalties
Delhi's Anti-Corruption Branch registered the underlying case on May 11, 2024 on a complaint by the Directorate of Vigilance, alleging large-scale irregularities, manipulation of tender conditions and criminal conspiracy in the tendering process for the augmentation and upgradation of sewage treatment plants of the Delhi Jal Board rediff.com indiatoday.intoday.in. On 2026-08-18, six people were arrested in connection with the case, and the matter was produced before a Special Judge the following day thehindu.com rediff.com. The tender is the subject of a corruption investigation rediff.com.
Specification read — Delhi DJB STP augmentation, ~10 plants, ~1,943 crore programme
10 sewage treatment plants across a single utility, scoped for augmentation and upgradation, is a multi-package retrofit of brownfield sites rather than greenfield construction. The outlet-reported envelope of Rs 1,943 crore across the four DJB tenders at issue works out to roughly Rs 194 crore per plant on average indiatoday.intoday.in; for a 10-plant cluster, individual plant capacities in the 100–500 MLD band are the realistic operating point, where a single train typically takes a 50–150 MLD slot and a 300 MLD site is built as two or three parallel trains. The class of upgrade the news describes is an IFAS / moving-bed biological stage retrofitted into existing concrete tanks, with the existing primary settling and secondary clarifier envelopes kept and the biological reactor volume and media surface area expanded; tertiary filtration and chlorination or UV trains are usually added or rebuilt at the same time to meet the treated-effluent parameters the river-loading case turns on. An IFAS upgrade normally buys back 50–100% of rated hydraulic capacity on a constrained footprint without new civil works, which is why utilities specify it where land is the binding constraint. The headline dispute is not about whether IFAS works, but about whether the tender's technical specifications were written to be technology-neutral or to favour a single supplier of fixed-film media, and the same procurement question lands on every plant manager who has watched a tender come back with one qualified bidder. If your site is a 100–300 MLD municipal STP running on conventional activated sludge, BOD 200–350 mg/L and COD 400–700 mg/L in the influent, ammonia-sensitive in the receiving stretch and land-locked so you cannot build a new aeration tank, an IFAS or MBBR retrofit of the existing biological stage is the move that keeps the rest of your treatment train unchanged and gets you back inside your discharge consent, and the packaged biological retrofit range is the part of the catalogue to compare on media fill ratio and guaranteed effluent.
New Builds, Upgrades & Capacity Expansion
Tiruchi Corporation's 100 MLD sewage treatment plant at Panjapur is under construction and the civic body expects the project to be completed by August thehindu.com. The same report lists several other Tiruchi Corporation projects — including the integrated vegetable market at Panjapur, Packages I and II of the inner link road along the Koraiyar and Kudamurutti river bunds, and Phase IV of the underground drainage project — as progressing slowly, with funds under the Tamil Nadu Urban Road Infrastructure Fund yet to be released and limited manpower deployed at sites thehindu.com. The proposed Bio-CNG plant and automated material recovery facility at the Ariyamangalam dumpyard, and the construction and demolition waste processing facility at Panjapur, are yet to commence thehindu.com.
Specification read — Tiruchi 100 MLD STP, greenfield, municipal
100 MLD is the headline number on the Panjapur plant, and that converts to 100,000 m³/day, in the band of a mid-sized Indian municipal STP serving roughly 500,000 population equivalent at 200 litres per capita per day thehindu.com. At this scale a single biological train is impractical, so the realistic layout is two or three parallel 33–50 MLD trains, each running screening → grit removal → primary clarification (often skipped on Indian municipal STPs in favour of direct biological treatment) → biological stage → secondary clarification → tertiary filtration → chlorination or UV disinfection, with the biological stage almost always an ASP or A2O variant when the treated effluent discharges to a freshwater body, or an MBR when space is constrained and the consent demands low TSS. A 100 MLD municipal plant in this class typically specifies influent BOD 200–300 mg/L, COD 400–600 mg/L, TSS 300–500 mg/L and an effluent target in the BOD <10 mg/L, COD <50 mg/L range to meet the receiving-water consent the contract will be measured against. The interesting procurement point in the Tiruchi story is not the STP itself, which is moving, but the cluster it sits inside: UGD Phase IV is slow, several road and drain works are unfinished, and the contractor base is throttled by pending fund release under TURIF, so the STP is being delivered into a drainage catchment that is still being built thehindu.com. If your plant is a 50–150 MLD greenfield municipal STP, BOD 250 mg/L, COD 500 mg/L, TSS 400 mg/L in, effluent to a river, with a parallel UGD network still under construction and a budget that releases in tranches, a modular underground package STP on the smaller satellite catchments buys you early commissioning while the main 100 MLD plant comes up, and the procurement question is sequencing the package plants to the UGD handover dates, not selecting them later.
FAQ
What does a 100 MLD municipal sewage treatment plant typically cost to build in India?
As a general engineering range rather than a reported figure for the Tiruchi project, a 100 MLD municipal STP in India typically lands in the Rs 80–150 crore capital cost band for civil + mechanical + electrical works, with the biological stage — ASP, A2O or MBBR — driving most of the variance. The Tiruchi project itself is described as progressing and expected to be completed by August thehindu.com.
How long does it take to commission a 100 MLD STP from notice to proceed?
As a general engineering range, a greenfield 100 MLD municipal STP runs 24–36 months from notice to proceed to mechanical completion, plus 3–6 months of commissioning and stabilisation of the biological stage before treated-effluent parameters are met. The Tiruchi plant has been under construction against an August completion target thehindu.com.
What BOD reduction can an IFAS retrofit deliver on an existing activated-sludge tank?
As a general engineering range, an IFAS or MBBR retrofit into an existing aeration tank typically lifts MLSS to 4,000–6,000 mg/L without raising the clarifier solids load proportionally, and delivers an additional 30–50% BOD removal headroom on the same tank volume. The class of upgrade is what the Delhi Jal Board programme at issue covers indiatoday.intoday.in.
What is the difference between IFAS and MBBR for a brownfield STP upgrade?
Both are moving-bed biological stages, but IFAS keeps the mixed liquor suspended and adds free-floating media in the same tank, while MBBR operates with the entire biomass attached to the media and no return activated sludge. IFAS is the typical choice when the existing activated-sludge train must be preserved and a conductivity-based aeration control loop is already in place.
How is a packaged underground STP sized for a 50,000 population equivalent catchment?
At 150 litres per capita per day, 50,000 PE is roughly 7.5 MLD, which is a realistic upper limit for a single skid of the WSZ underground package plant range; above that, the design moves to a civil-tank build because tank diameter and haulage constraints stop scaling the package further. Procurement windows on these units are typically 8–14 weeks ex-works.
