Executive summary
Supreme Decree No. 17/2025 of the Ministry of the Environment took effect on January 21, 2026, amending the Environmental Impact Assessment System (SEIA) Regulation (SD No. 40/2012). The changes affect two fronts: who must enter the SEIA when modifying an existing project, and what thresholds determine whether a new project requires environmental assessment. If your company has projects in processing, modifications in the pipeline, or is near the Article 3 thresholds, this directly affects you.
What changed
The decree amends Articles 2 and 3 of the SEIA Regulation. This is not a minor technical revision. It changes the entry rules for an entire category of project modifications and raises thresholds across several relevant typologies.
On modifications, the new wording of Article 2(g) excludes from the SEIA re-entry requirement those modifications that: (1) correspond to the same typologies already assessed in the original project, and (2) do not substantially alter the environmental impacts or the measures committed in the existing Environmental Qualification Resolution (RCA).
On thresholds, the decree touches more sectors than typically mentioned. Changes cover energy, fuels, real estate, tourism, mining, aquaculture, chemicals, transport, and the entire waste chain (household, industrial, hazardous, and healthcare). The table below summarizes the 20 modified typologies.
The changes with the greatest immediate operational impact include:
- Electric transmission lines (Art. 3(b)(1)): a minimum length criterion of 2 kilometers is added. It is no longer sufficient to exceed 23 kV — the route must also meet that threshold.
- Fuel stations (Art. 3(e)(6)): the storage capacity threshold rises from 200,000 to 850,000 liters.
- Real estate equipment projects (Art. 3(g)(1)(2)(b)): the criterion changes from total land area (≥ 20,000 m²) to land area to be developed (≥ 15,000 m²).
- Peat extraction (Art. 3(i) and (i)(6)): the typology is completely eliminated.
- Tailings reprocessing (Art. 3(i)(1)): exceptions are incorporated for projects with an existing RCA that reprocess fresh tailings or recover bulk waste, subject to capacity being below 25% of authorized nominal capacity.
- Hazardous substances (Art. 3(ñ)): storage thresholds increase dramatically across all subcategories. Toxic substances rise from 30 tons to 2,500 tons; flammable substances from 80,000 liters to 1,000 tons; hazardous substance transport from 400 to 2,500 tons/day.
Comparative table: key changes to Article 3
Finally, the decree amends Article 60 of the SEIA Regulation to require that RCAs expressly identify the project or activity typologies, including those applicable to its parts, works, and actions under Article 3. This is relevant going forward: an RCA that does not expressly identify typologies makes it harder to determine whether a future modification qualifies under the Article 2(g) exception.
Transition: Projects submitted to the SEIA before January 21, 2026, continue to be processed under SD No. 40/2012, including admissibility rules. The new regime applies only to submissions after that date.
What this could mean for your company
The change in project modifications has the greatest immediate operational impact. Many companies with projects holding existing RCAs currently avoid re-entering the SEIA based on case-by-case legal advice, without a clear regulatory rule. DS 17/2025 provides that clarity — but with a condition that must be read carefully: the modification must not "substantially" alter the impacts or committed measures. That adjective will generate controversy. The Environmental Assessment Service (SEA) will need to rule on what counts as "substantial," and the first months will likely bring inconsistent criteria across different Regional Directorates.
For electric sector projects, the 2 km threshold on transmission routes is concrete and directly applicable. Reinforcement or grid extension projects that previously bordered on the entry obligation may now be exempt.
For the fuel sector, the increase to 850,000 liters for fuel stations dramatically reduces the universe of projects subject to EIA or DIA. Most urban fuel stations fall below that threshold.
For real estate, the change in typology g.1.2.b is more complex than it appears: the threshold drops from 20,000 m² to 15,000 m², but the criterion shifts from total land area to area to be developed. In projects where the developed area is significantly smaller than the total lot, the net effect may be an exemption. In others, the opposite may occur.
What you can do
If your company has an existing RCA and modifications in the pipeline, the first task is to review whether those modifications qualify under the new Article 2(g) exception. For that you need: (1) to verify that the modification typologies match those already assessed in the original RCA — and if the RCA does not expressly identify them, that is a problem to manage — and (2) to have a well-founded analysis of why the impacts and measures are not substantially altered. That analysis must exist in writing before deciding not to re-enter.
If your project is in the design phase and near any of the modified thresholds — electric transmission, fuel stations, hazardous substances, real estate, aquaculture, or waste — it is worth reviewing whether the new wording changes the entry obligation.
And if you have projects in processing submitted before January 21, the previous regime applies in full. There is no transitional benefit.
If you have questions about how DS 17/2025 applies to a specific project or modification: schedule a consultation with Cubillos Lama
This content is for informational purposes only and does not constitute legal advice for any specific case.