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Environmental impact authorization in Uruguay

Last verified: 2026-10-27 · Status: Stable

Listed projects, from roads and ports to power plants above 10 MW, industrial plants over one hectare, urban developments over 10 hectares and works in the coastal strip, need a prior environmental authorization (AAP) from the Ministerio de Ambiente before any works start. The developer communicates the project, the Ministry classifies it as A, B or C within 10 business days (40 for sensitive sites), and categories B and C need an impact study, a 20 business day public review and, for C, a public hearing; the Ministry then has 120 days, and silence means denial. Many plants also need an operating authorization renewed every three years, and building without the AAP is a serious infraction with fines up to 50,000 UR (about US$2.4 million).

USD figures use UYU 40.210 per US dollar, the BCU quotation for DLS. USA BILLETE on 27 October 2026; amounts in Unidades Indexadas (UI) use UYU 6.6792 per UI, the BCU quotation for 27 October 2026, both retrieved from the BCU quotations service on 27 October 2026. Amounts in Unidades Reajustables (UR) use UYU 1,940.77 per UR, the value fixed by Decreto 229/026 (IMPO lists it as the latest UR, in force for September 2026). Conversions are rounded and for orientation only.

Key facts

Deadline to classify a project (A, B or C)	10 business daysDecreto 349/005 art. 6 (Decreto 416/013), as of 2026-10-27 · in force
Classification deadline for sensitive projects with site study	40 business daysDecreto 349/005 art. 21, as of 2026-10-27 · in force
Public review of the summary environmental report	20 business daysDecreto 349/005 art. 15, as of 2026-10-27 · in force
Deadline to decide the prior environmental authorization	120 daysDecreto 349/005 art. 18, as of 2026-10-27 · in force
Effect of silence on the authorization request	Deemed denial Decreto 349/005 art. 18, as of 2026-10-27 · in force
Public hearing	Mandatory for category C Decreto 349/005 art. 16, as of 2026-10-27 · in force
Environmental operating authorization renewal	3 yearsDecreto 349/005 art. 23, as of 2026-10-27 · in force
EIA required for industrial plants with industrial area above	1 hectaresDecreto 349/005 art. 2 num. 19, as of 2026-10-27 · in force
EIA required for urban developments above	10 hectaresDecreto 349/005 art. 2 num. 24, as of 2026-10-27 · in force
EIA required for transmission lines of	150 kV or moreDecreto 349/005 art. 2 num. 18, as of 2026-10-27 · in force
Government fee for the prior environmental authorization	None set in Ley 16.466 or Decreto 349/005 Ley 16.466; Decreto 349/005, as of 2026-10-27 · in force

The rule

1. Prior authorization is needed before starting listed activities, constructions or works, public or private, including: new national or departmental roads and widenings affecting more than 10 hectares; new rail sections; new bridges; airports; ports and marine works; oil or chemical transfer terminals; oil and gas pipelines over 10 km; outfalls over 50 m into the receiving body; hazardous waste plants; solid waste plants or landfills of 10 tonnes per day or more; sewage plants serving more than 10,000 people; mining that opens mines or new drilling; fossil fuel extraction; power plants of more than 10 MW of any source and expansions that raise capacity or change the primary source; nuclear plants; transmission lines of 150 kV or more; industrial or agro industrial plants with more than one hectare of industrial area, metal foundries of 50 tonnes a year or more, or making hazardous chemicals; hazardous goods depots; free zones and industrial parks; tourist complexes; urban developments over 10 hectares or near existing towns; dams over 2 million cubic metres or 100 hectares; large irrigation works; new forest plantations of more than 100 hectares in one holding; cemeteries; works in the coastal defence strip; and works in protected areas without an approved management plan.
Cost to do it: No authorization fee is set in Ley 16.466 or Decreto 349/005; cost is the study by qualified professionals and the publications.
Example: A 2 hectare food processing plant near Canelones exceeds the one hectare industrial threshold and needs an AAP before construction. / A US$60 million 40 MW solar park exceeds 10 MW and needs an AAP before groundbreaking.Ley Nº 16.466 (Environmental Impact Assessment), art. 6 and 7; Decreto Nº 349/005 (Regulation of Environmental Impact Assessment and Environmental Authorizations), art. 2 as amended, Ley 16.466 art. 6 and 7; Decreto 349/005 art. 2, 2005-09-21 official text · verified 2026-10-27

2. The developer must first communicate the project to the environmental authority with the identity of the owners and landowners, the responsible technicians, location and description of the area and project, likely impacts with prevention and mitigation measures, a proposed classification and an environmental sheet. The Ministry has 10 business days to confirm or change the classification; if it does not decide in time, the developer's proposed classification is deemed confirmed. The term is interrupted if information is incomplete and restarts once it is completed. Category A projects have only non significant impacts and receive the AAP without further procedure, possibly with conditions; category B projects have moderate significant impacts and need a sectoral impact study whose scope the Ministry defines; category C projects may cause significant negative impacts and need a full impact study.
Cost to do it: No fee; professional time to prepare the communication and environmental sheet.
Example: A project communicated on 2 November 2026 must be classified by 16 November 2026, or the developer's own classification stands. / A foreign developer that proposes category A for a project the Ministry reclassifies as C faces a full study and a public hearing, adding months to the timetable.Decreto Nº 349/005, art. 3 to 8 (art. 6 inciso 1 as amended by Decreto Nº 416/013), Decreto 349/005 art. 3 to 8, 2013-12-19 official text · verified 2026-10-27

3. For category B and C projects the developer files the AAP request with the project documents and the environmental impact study, which must describe the receiving environment, identify and assess impacts, set mitigation measures and a monitoring plan, covering construction, operation and abandonment. Parts that are trade or industrial secrets may be filed separately and kept confidential if the authority agrees, but must be the minimum possible. The study and summary must be signed by a qualified university professional, who is responsible to the Ministry; officials of the Ministry or of public bodies deciding on the project cannot sign.
Cost to do it: Cost of the multidisciplinary study team and the signing professional; no official fee set.
Example: A Uruguayan quarry expansion classified B needs a sectoral study signed by a qualified geologist or engineer. / A foreign mining investor can keep its ore processing know how confidential by filing it in a separate document.Ley Nº 16.466 art. 12 and 15; Decreto Nº 349/005 art. 9 to 12 and 19, Decreto 349/005 art. 9 to 12 and 19, 2005-09-21 official text · verified 2026-10-27

4. Once the request is complete, the Ministry places the summary environmental report on public view and the developer must publish notices in the Diario Oficial, a national newspaper and a local newspaper; anyone may submit written comments during 20 business days from the day after the last publication. A public hearing is mandatory for all category C projects and optional for others with significant cultural, social or environmental effects. The Ministry must grant the AAP if residual impacts are admissible, may grant it subject to modifications or mitigation, and must deny it if residual impacts are not admissible; the authorization sets its own term of validity. The Ministry has 120 days to decide, suspended while corrections are requested, and silence at the end of the term is deemed a denial.
Cost to do it: Publication costs of the notices (non official notices at least 7 cm by two columns) and hearing logistics; no official fee set.
Example: If the last newspaper notice appears on Friday 6 November 2026, the public review runs from 9 November to 4 December 2026 (20 business days), before the 120 day decision clock matters. / A US$200 million port terminal classified C should plan for a public hearing and up to 120 days for the decision after a complete file, with silence meaning denial, not approval.Ley Nº 16.466 art. 13, 14 and 16; Decreto Nº 349/005 art. 15 to 18, Decreto 349/005 art. 15 to 18, 2005-09-21 official text · verified 2026-10-27

5. For oil and chemical transfer terminals, waste and sewage plants, power plants above 10 MW, nuclear plants, industrial complexes, hazardous goods depots, public cargo and passenger terminals, free zones, industrial parks, tourist complexes and cemeteries, the developer must communicate the project as early as possible, file a copy with the departmental government, and include a site selection study with alternatives. The classification term is then 40 business days, including a 10 business day public review, and departmental governments may comment within the first 20 business days. The classification certificate states whether the proposed sites are environmentally viable, and a non viable site cannot proceed to an AAP request.
Cost to do it: Cost of a site selection and alternatives study; no fee set.
Example: A planned industrial park in Paysandú must file its site study and wait up to 40 business days for a viability statement. / A foreign energy company comparing two sites for a 100 MW plant should present both; a non viable site is ruled out before the full study.Decreto Nº 349/005, art. 20 to 22 (art. 20 as amended by Decreto Nº 162/014), Decreto 349/005 art. 20 to 22, 2014-06-04 official text · verified 2026-10-27

6. Operation of authorized projects such as ports, terminals, waste and sewage plants, mines, fossil fuel extraction, power plants, industrial complexes, hazardous depots, terminals, free zones, industrial parks and tourist complexes requires an environmental operating authorization (AAO), granted after checking compliance with the AAP and renewed every 3 years, which reviews environmental management plans, emissions and waste approvals. Existing industrial plants and open pit mines that operated without an AAP need a special environmental authorization; plants may expand while it is processed if they notified the expansion at least 30 days before works start.
Cost to do it: Cost of renewal studies and management plans every three years; no fee set in the decree.
Example: A Uruguayan cement plant authorized in 2023 must renew its AAO by 2026 and again in 2029. / A foreign owned free zone operator should calendar AAO renewals every three years in its compliance plan.Decreto Nº 349/005, art. 23 to 25 (art. 23 as amended by Decreto Nº 162/014, 271/018 and 368/018); Ley Nº 16.466 art. 17, Decreto 349/005 art. 23 to 25, 2018-11-05 official text · verified 2026-10-27

7. Serious infractions include building a project that could be classified B or C without an AAP, operating without having requested the AAO, expanding without the special authorization, omitting or falsifying environmental information, and breaching authorization conditions in a way that harms or risks the environment. Landholders and their successors, as well as the professionals in charge, are jointly liable, administratively and civilly, for works done without authorization or in breach of its conditions. The Executive may suspend authorized works at any time by reasoned resolution, and fines for environmental infractions range from 10 UR to 50,000 UR. These powers now belong to the Ministerio de Ambiente, created in 2020, which took over the competences of the former Dirección Nacional de Medio Ambiente (DINAMA) and the environmental competences of the housing ministry.
Cost to do it: Fines from 10 UR (about UYU 19,408, US$483) to 50,000 UR (about UYU 97,038,500, US$2.41 million).
Example: A developer who starts earthworks for a 15 hectare gated community before the AAP commits a serious infraction and the landowner is jointly liable. / For a foreign investor the maximum fine is about US$2.41 million, but suspension of works and joint liability of landowners are the larger risk.Decreto Nº 349/005 art. 29; Ley Nº 16.466 art. 8 and art. 11 as reworded by Ley Nº 19.924 art. 521; Ley Nº 16.112 art. 6 as reworded by Ley Nº 19.535 art. 168; Ley Nº 19.889 art. 291 and 293, Decreto 349/005 art. 29; Ley 16.466 art. 8 and 11; Ley 16.112 art. 6; Ley 19.889 art. 293, 2020-07-09 official text · verified 2026-10-27

Step	Term	Source
Project communication and proposed category	Before any works	Decreto 349/005 art. 4
Classification (A, B, C)	10 business days; silence confirms the proposal	art. 6
Classification for sensitive projects with site study	40 business days	art. 21
Impact study and AAP request (B and C)	Developer's timing	art. 9 to 12
Public review	20 business days after last notice	art. 15
Public hearing	Mandatory for C	art. 16
Decision	120 days, suspended for information requests; silence is denial	art. 18
Operating authorization	Before operation, renewed every 3 years	art. 23 and 24

Procedure and timeline

Activity	Threshold
Power plants	More than 10 MW, any source
Transmission lines	150 kV or more
Industrial plants	More than 1 hectare of industrial area, or foundries of 50 t/year or more, or hazardous chemicals
Urban developments	More than 10 hectares, or near existing towns
Solid waste plants and landfills	10 t/day or more
Sewage plants	Serving more than 10,000 people
Pipelines	More than 10 km
Dams	More than 2 million m3 or 100 ha of water surface
New forest plantations	More than 100 ha in one holding

Selected thresholds (Decreto 349/005 art. 2)

Worked example

Wind farm timeline: a 50 MW wind project is communicated with a site study on 2 November 2026. Classification takes up to 40 business days, to early January 2027 (Decreto 349/005 art. 21). If classified B, the sectoral study is filed, say, in March 2027; after the 20 business day public review and up to 120 days of review, the AAP can be expected in the third quarter of 2027, and operation then needs an AAO renewed every three years.
Fine exposure: starting construction without an AAP is a serious infraction (art. 29 a), with fines up to 50,000 UR, about UYU 97,038,500 or US$2.41 million (Ley 16.112 art. 6), plus suspension of works by the Executive (Ley 16.466 art. 8).
Category A route: a small project that the Ministry confirms as category A within 10 business days receives the AAP without a study, possibly subject to mitigation conditions (Decreto 349/005 art. 6 and 8).

Step by step

Check the activity and size against Decreto 349/005 art. 2 early in project design.
For sensitive projects, prepare a site selection study with alternatives and file a copy with the departmental government.
Communicate the project with a realistic proposed category, signed by a qualified professional.
For categories B and C, commission the impact study covering construction, operation and abandonment, and separate any trade secrets.
Publish the notices, manage the 20 business day public review and, for C, the public hearing.
Do not start works before the AAP; build the 120 day decision term (with silence as denial) into financing and construction contracts.
Before operating, obtain the AAO and calendar its renewal every three years.

Common traps

Silence on the AAP request is a denial, not an approval; only the classification step has positive silence.
Proposing too low a category can backfire if the Ministry reclassifies the project.
Landowners and professionals in charge are jointly liable for unauthorized works, so lenders and landlords should check the AAP.
The AAP sets its own validity period; delays in starting works can make it lapse.
Many projects need a second authorization (AAO) to operate, renewed every three years.
Departmental permits and land use rules apply in addition to the national environmental authorization.

Sources

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