Mine Closure and Remediation: What Happens When a Lithium Project Ends

A mining project is also planned for its end

In the lithium industry, we often talk about exploration, construction and production, but rarely about the final chapter: closure. Yet in modern mining, decommissioning and remediation are an integral part of the project life cycle and must be planned from the outset, not when reserves run out. A salt flat can sustain operations for 30 or 40 years, and the decisions made at the first well shape the closure tasks that will occur half a century later.

Closure is not an event but a process: it includes shutting down industrial facilities, final disposal of waste, physical and chemical stabilization of the intervened terrain, and subsequent monitoring, which can extend for many years beyond the last ton produced. Thinking about the end from the beginning reduces costs and environmental liabilities.

What the regulations require: the closure plan

In Argentina, the Environmental Protection Law for Mining Activity (Law 24,585, incorporated into the Mining Code) requires the submission of an Environmental Impact Report covering all project stages, including closure. This must be updated periodically —generally every two years— and describe how the site will be restored to environmentally safe conditions. The enforcement authorities are provincial, since ownership of the resources belongs to the provinces, which creates regulatory nuances among Catamarca, Salta and Jujuy.

A robust closure plan details the dismantling of evaporation ponds, processing plants, camps and roads; the management of residual brines and waste salts; and land rehabilitation targets. The international trend, aligned with standards such as those of the ICMM or the IRMA framework, points to the concept of "progressive closure": remediating areas as they cease to be used, rather than waiting for the end of operations.

Guarantee funds: who pays for remediation

One of the classic risks of mining is that a company disappears or goes bankrupt before fulfilling remediation obligations, leaving the liability to the State. To prevent this, there are financial guarantee instruments: the company sets aside provisions —through surety insurance, trusts, bank guarantees or dedicated funds— reserved to finance closure even if the operator cannot afford it.

The amount is calculated based on the estimated cost of closure tasks and is usually revised throughout the project's life. In medium-scale lithium operations, closure provisions can represent a significant percentage of capital, and their proper establishment is a point of growing scrutiny by institutional investors and financiers who apply ESG criteria before committing capital.

The particular challenge of remediating a salt flat

Remediating a Puna salt flat is not like rehabilitating a hard-rock mine. Brine extraction intervenes in a delicate hydrogeological system: pumping alters aquifer levels, the interface between freshwater and brine, and the water balances of high-Andean wetlands that depend on those flows. The effects can manifest slowly and persist for decades after the first well, making it difficult to distinguish the project's own impact from the natural variability of the system.

That is why salt flat remediation requires solid baselines —measurements taken before operations begin— and sustained long-term hydrogeological monitoring. Returning the terrain to an "original" state may be unfeasible; the realistic goal is a stable, safe condition compatible with land uses and with surrounding ecosystems and communities. Evaporation ponds, moreover, leave large surfaces with salt crusts whose reintegration into the landscape is technically complex.

The long term: monitoring and post-closure care

The physical closure of facilities is only one part. The post-closure phase involves monitoring water quality, soil stability, and the recovery of vegetation and fauna for years. In brine systems, where hydrogeological responses are slow, this care period may require commitments of two or three decades, with public reporting and independent audits.

Documentary traceability is key: records of what was extracted, where and how, allow responsibilities to be assigned and effective remediation to be designed. The absence of historical data is precisely what turns many inherited environmental liabilities into costly, hard-to-solve problems.

Argentina and the Puna: an opportunity to do it right

Argentina is the world's fifth-largest lithium producer, and much of its potential rests on the low-cost salt flats of the Puna. With new projects entering under frameworks such as the RIGI in force since 2024, the country has the opportunity to incorporate first-rate closure and remediation standards from the design stage, avoiding the mistakes of other mining basins.

The challenge is twofold: to require realistic closure plans and sufficient guarantee funds, while also developing local technical capacity to monitor salt flats over decades-long horizons. A well-executed closure is not a residual cost but a condition of social license and business sustainability. In a strategic resource like lithium, the way projects end will define as much as the way they begin.