In a tender for a closed mine, the service sought can be measured in months. A month in which someone runs a treatment plant, maintains it and deals with water from old mine workings.
I matched the official list of mines approved for closure to seven procurement notices for mine-water treatment. The same names travel from decisions made in 1998–1999 into tenders published in 2024–2025. All seven describe water carrying heavy metals and seek a service repeated over time.
Reading the documents together changes what “closed” means. The economic activity can end while the work required by the water continues. For people downstream, that second activity matters long after the first has gone.
[1]Rock does not read government decisions
Mining opens routes for water and air. Workings, excavated rock and processing waste increase the mineral surface area exposed to water and oxygen. Oxidation of sulfur-bearing minerals can generate acidity; water can dissolve and carry metals. Microorganisms can accelerate the reactions.
Stopping extraction does not remove rock already exposed, and it is not equivalent to stopping water circulation. These processes can require water collection, treatment and monitoring after closure. A scientific review published by the USGS describes the mechanism; the duration and engineering solution depend on the site.
Not all mine water is acidic. Neutral or alkaline drainage can also contain elevated metal concentrations. The drawing explains a mechanism, not the condition of a particular river.
[2]Seven names carried from one list into another
Choose a place and compare its closure record with the service sought much later. The decision year is the year of approval, not the date of the last tonne extracted or proof that every closure operation was completed.
Bistrița-Năsăud
- Monthly estimate, excluding VAT
- 150,206 lei
- Maximum framework horizon
- 48 months
- Operating mode named in the notice
- by-pass
Boița Hațeg also has an intermediate record. Hunedoara Prefecture’s report for 2016 describes treatment under post-closure monitoring activities. There is an official account of work between the old decision and the recent tender.
The 2003 annex had already separated money for running treatment plants from other monitoring operations. Continued work was anticipated in the very documents organizing closure.
[3] [1]A four-year contract does not set an end date for treatment
Each of the seven notices sets out a framework of up to 48 months. Within it, individual call-off contracts can cover between one month and one year. The document puts a calendar around a physical need. It does not give a date when the water will stop needing management.
The figures in the records are the buyer’s published estimates before award. They are not invoices or evidence of money paid. Nor are they an efficiency ranking: two notices specify “by-pass”, four specify normal operation, and one leaves the mode unspecified in its monthly estimate. These packages should not be treated as identical services.
“By-pass” is retained exactly as written. That term alone does not prove discharge of untreated water, actual use of the mode or a permit breach.
At Novăț, two basins work while the third is cleaned
The installations in this story do not all use the same principle. At the Novăț tailings pond, in the Baia Borșa mining area, a 2025 procurement describes passive treatment. Seepage is collected, separated from rainwater and carried by gravity to three basins filled with limestone of 80-millimetre particle size.
Passing through the basins allows neutralization and partial removal of metals through precipitation and settling. The resulting sludge accumulates. “Passive” describes how treatment works. The contract still requires operation and maintenance. Each basin must be cleaned once every four months; while one is being cleaned, the other two remain in operation. Continuity has a concrete form: one basin can be taken out of the circuit without all three stopping.
[4]Choose the basin being cleaned. The other two remain in operation.
COLLECTED WATER
OUTFLOW
Two basins operating. One basin being cleaned.
A diagram of the alternation described in the procurement. It is not live plant status or an actual maintenance schedule. Pipe positions are schematic.
The contract awarded in 2025 for this service is valued at 550,560 lei excluding VAT, over 12 months. The award notice records a contract; it does not certify payments, completion of every task or the quality of discharged water. Those require other records.
At Novăț, a routine survives the mine: basins cleaned in turn, flow measured, a system maintained. A photograph of a ruin can conceal precisely this work.
[4]In May 2023, pollution spread over 30 kilometres
Mine water from the former Isipoaia site in Suceava reached the Bistrița River. Romania’s Environment Ministry identified the source on 14 May 2023. The following day, the national water authority reported a pollution wave extending 30 kilometres through Suceava and Neamț counties.
Temporary restrictions on using surface water for animals, fishing and other activities remained in place. The same statement said no fish mortality had been reported and that water at the entry to the Izvorul Muntelui reservoir was within normal quality limits. These observations belong to the same event.
Isipoaia is not one of the seven treatment plants in the tender selection. The event demonstrates consequences beyond an industrial boundary. It does not establish a failure at the plants presented here, or describe the Bistrița’s condition today.
[5] [6]What, then, does it mean to close a mine?
Production has a last tonne. The documents examined here give no equivalent endpoint for water management. A decision approves closure. A notice requests months of service. A laboratory result describes a sample. Each answers a different question.
To follow what happens after closure, these questions need to be asked together. Who manages the water? What installation exists, and in what mode does it operate? Which tasks were completed? What did the samples show? When the contract ends, who ensures the service continues?
Mine closure is also a transfer of responsibility. The remaining work can move from the extracting enterprise to the institutions and contractors responsible for the site, and the budgets funding its maintenance. Part of the industrial inheritance is the repeated work of managing water, long after the ore has left.
How I followed the same places
The selection joins seven TED notices, six published in October 2024 and one in May 2025. I matched their names to Annex 2 of Government Decision 926/2003, which identifies earlier closure approvals. The passive Novăț example is separate, using the technical description and award published in SICAP. Records were checked on 3 September 2026.
This is not a census of Romanian mines, treatment plants or costs. Year gaps subtract document years; they do not measure pollution duration. Monthly values come from the estimate descriptions. Multiplying each by 48 reproduces the estimated ceiling for that framework. Frameworks, call-offs and invoices are not added together.
I conducted no site inspections, water sampling or contract-performance audit. The evidence establishes decisions, requested services and a reported historical incident. Present water quality, completed work and actual payments require separate verification. Corrections to the notices or new documents that change the interpretation would trigger an update.
Download the verifiable table · CSV ↓| Plant | Tender | Monthly estimate, lei excl. VAT | Mode |
|---|---|---|---|
| Rodna Valea Vinului | 2024-10-17 | 150,206 | by-pass |
| Boița Hațeg | 2024-10-23 | 104,019 | normal |
| Mestecăniș | 2024-10-17 | 123,701 | not specified in the monthly estimate |
| Nistru 9 Mai – 11 Iunie | 2024-10-16 | 306,614 | by-pass |
| Aluniș Fața Mare – Valea Colbului | 2024-10-16 | 165,076 | normal |
| Tyuzosa | 2024-10-16 | 106,658 | normal |
| Toroioaga | 2025-05-22 | 181,047 | normal |
The documents behind the story
- Official annex: mine names and closure decisions
- USGS review: the chemistry of mine drainage
- Hunedoara Prefecture, 2016 report, p. 16
- Novăț: technical description and award, SICAP
- Environment Ministry: source identification, 14 May 2023
- Romanian Waters: findings and their limits, 15 May 2023
The seven European notices are linked individually in the table above.