October 2026
Determining the “Implementation of Development Activities” Under the Taiwan EIA Act and the Threshold for Conducting a New Environmental Impact Assessment Following Project Modifications – Lessons from the Dispute over the Taipei MRT Wanda Line Realignment
On November 6, 2025, the Taipei High Administrative Court rendered Judgment Su Zi No. 636 of 2023, addressing the legal standards for determining what constitutes the“implementation of development activities”under Article 16-1 of the Environmental Impact Assessment Act (the “EIA Act”) and whether modifications to a development project require a new environmental impact assessment (“EIA”). In its judgment, the Court examined the actual implementation of the development project and specifically assessed the environmental impacts before and after the proposed modifications. Subsequently, on May 20, 2026, the Supreme Administrative Court rendered Judgment Shang Zi No. 7 of 2026, dismissing the appeal and upholding the lower court's judgment. This article summarizes the Taipei High Administrative Court's factual findings and legal reasoning, supplemented by the key points from the Supreme Administrative Court's press release, as follows:
I. Background
The Department of Rapid Transit Systems of the Taipei City Government (the “DORTS”) obtained a development permit on October 25, 2018, for Phase II of the Wanda–Zhonghe–Shulin MRT Line Project (the “Project”). Subsequently, due to modifications to station locations, structural designs, construction plans, the volume of surplus excavated soil, and ancillary MRT facilities, DORTS submitted the Third Environmental Impact Difference Analysis Report (the“EIA Difference Analysis Report”), which was approved with revisions by the competent EIA authority on June 10, 2022.
However, local residents and environmental groups argued that DORTS had not commenced implementation of the Project until more than three years after obtaining the development permit and therefore should have submitted an Environmental Status Difference Analysis and Countermeasure Review Report pursuant to Article 16-1 of the EIA Act. They further contended that the archaeological investigation conducted by DORTS at the Zhanlongshan Archaeological Site in 2020 constituted merely a pre-development environmental survey and could not be regarded as the implementation of development activities.
In addition, they asserted that the relocation of LG11 Station to Jincheng Park, the realignment of the MRT tracks from a straight alignment to a curved alignment, the increase in surplus excavated soil, and the transplantation of vegetation could potentially exacerbate adverse impacts on the surrounding environment. Accordingly, they maintained that a new EIA was required under Article 38, Paragraph 1, Subparagraphs 4 and 5 of the Enforcement Rules of the EIA Act, and consequently initiated administrative litigation.
II. Factual Findings and Legal Reasoning of the Taipei High Administrative Court
1. The “Implementation of Development Activities” under Article 16-1 of the EIA Act Should Be Determined Based on Whether Substantive Construction Work Has Commenced, and the Archaeological Investigation in This Case Constituted Part of the Development Activities
(1) Pursuant to Article 16-1 of the EIA Act, where a developer commences implementation of development activities more than three years after obtaining development approval following the completion of an EIA review, the developer shall submit an Environmental Status Difference Analysis and Countermeasure Review Report to the competent authority for review and shall not commence implementation of the development activities until such review has been completed.
(2) The Taipei High Administrative Court held that whether “development activities have been implemented” should be determined based on whether “substantive construction work has commenced”. The Court further explained that the scope of development activities under the EIA Act encompasses the planning, implementation, and post-completion use of a development project. Accordingly, whether substantive construction work has commenced should be assessed in light of the nature of the development activities and the specific circumstances of each case, applying the rules of experience and logic, rather than solely by reference to whether construction of the main project works has begun.
(3) In the present case, the Court found that the development permit for the Project was issued on October 25, 2018, while the Zhanlongshan Archaeological Site was officially designated as an archaeological site by the New Taipei City Government on March 22, 2019. To accommodate the construction works and comply with archaeological site preservation requirements, DORTS incorporated the archaeological investigation and assessment work into the tender documents and awarded the relevant contract in August 2020. The contractor commenced work on September 10, 2020, and subsequently carried out construction activities on October 31, 2020, including the painting and removal of road markings and the installation of fences and steel guardrails.
(4) The Court further noted that, pursuant to Article 58, Paragraph 2 of the Cultural Heritage Preservation Act, when government agencies formulate plans for major construction projects, they must not interfere with the preservation and maintenance of archaeological sites and must first investigate whether any archaeological sites exist within the project area. Given that the Zhanlongshan Archaeological Site was located along the alignment of the Project, the relevant archaeological investigation was necessary to comply with cultural heritage preservation requirements and to ensure that subsequent construction works could proceed. Accordingly, such investigation should be regarded as an integral and inseparable part of the overall development activities.
(5) Accordingly, the Court held that the archaeological investigation conducted by DORTS at the Zhanlongshan Archaeological Site between September and October 2020 constituted the commencement of substantive construction work for the Project. As the Project had therefore been implemented within three years of obtaining the development permit, DORTS was not required to submit an Environmental Status Difference Analysis and Countermeasure Review Report pursuant to Article 16-1 of the EIA Act.
2. Whether Modifications to a Development Project Require a New EIA Should Be Determined Based on the Actual Environmental Impacts Before and After the Modifications
(1) Pursuant to Article 16 of the EIA Act and Article 38, Paragraph 1 of its Enforcement Rules, where a developer modifies a project that has already passed an EIA review, a new EIA must be conducted for the modified portions if the modifications are likely to exacerbate impacts on the living, natural, or social environment, or on protected objects within the affected area, or adversely affect the maintenance of environmental quality. In determining whether the modifications to the Project would result in increased environmental impacts or adversely affect the maintenance of environmental quality, the Court examined the following aspects:
A. Noise and Vibration Impacts
After reviewing the noise assessment results in the EIA Difference Analysis Report, the Court found that certain predicted noise levels at residential buildings near LG11 Station would exceed the applicable regulatory limits before mitigation measures were implemented. However, DORTS had planned to install four-meter-high double-curved noise barriers and floating slab tracks, and to adjust the track alignment to increase the minimum distance between the outer edge of the elevated structure and nearby residential buildings from 5.46 meters to 6.96 meters. Similar mitigation measures, including noise barriers, floating slab tracks, and track alignment adjustments, were also planned for the section near Tucheng Elementary School. Accordingly, the Court concluded that, following the implementation of these mitigation measures, operational noise levels would comply with the applicable regulatory standards.
In addition, according to the vibration predictions in the EIA Difference Analysis Report, vibration levels at nearby sensitive receptors were estimated to range from approximately 44.0 to 48.1 decibels, below both the human perception threshold of 55 decibels and the applicable vibration assessment standards. The anticipated vibration impacts were therefore considered minor.
B. Use of Jincheng Park and Safety Risks Associated with the Curved Track Alignment
The Court found that the relocation of LG11 Station to Jincheng Park was primarily intended to avoid the expropriation of private land and improve the convenience of transfers to the Bannan Line. According to the area occupied by park facilities as calculated in the EIA Difference Analysis Report, the area would decrease from approximately 1,482 square meters before the modification to 434 square meters after the modification. Furthermore, the new station would adopt an elevated structure, allowing the space beneath the station to remain available for public recreational use. Accordingly, the Court rejected the plaintiffs' argument that the area of the park occupied by the station should be calculated based on the entire projected footprint of the station structure.
Regarding safety concerns arising from the change in track alignment from a straight section to a curved section, the Court noted that the purpose of an EIA is to assess whether the impacts of development activities on the surrounding environment can be adequately controlled, rather than to regulate the inherent risks associated with construction projects. The Court further considered that trains entering and leaving LG11 Station would travel at approximately 20 kilometers per hour, that derailment protection curbs would be installed along both sides of the tracks, and that the MRT system would be equipped with a train monitoring system and an Automatic Train Protection (“ATP”) system capable of automatically reducing train speeds on curves or initiating emergency braking in the event of overspeeding. Accordingly, the Court found insufficient grounds to conclude that the modified track alignment would give rise to a high risk of derailment.
C. Increase in Surplus Excavated Soil and Transportation Impacts
In this case, due to the conversion of certain elevated sections and stations into underground structures, the estimated volume of surplus excavated soil increased from approximately 240,000 cubic meters to 760,000 cubic meters.
The Court reviewed the surplus soil transportation plan set out in the EIA Difference Analysis Report, including measures such as scheduling transportation during off-peak hours, using national highways, expressways, and suburban roads, and adjusting actual transportation routes in accordance with the instructions of the competent transportation authorities. The Court concluded that, despite the increase in the volume of surplus excavated soil, there were insufficient grounds to determine that such increase would exacerbate impacts on the surrounding living environment or adversely affect the maintenance of environmental quality.
D. Addition of a Substation and Transplantation of Vegetation
Regarding the addition of a main substation in Shengmin Park in Shulin District, the Court found that the substation constituted an ancillary facility of the MRT system. As its planned supply voltage was 161 kilovolts, it did not exceed the threshold of 161 kilovolts for land-based power facilities under the EIA screening criteria applicable at the time. Accordingly, the addition of the substation did not independently trigger the requirement to conduct an EIA.
With respect to the impacts on vegetation in Jincheng Park and Shengmin Park, the Court found that the affected vegetation primarily consisted of commonly planted tree species, with no rare or endangered plant species involved. The EIA Difference Analysis Report had proposed transplantation and replacement planting measures for the affected trees. Specifically, 120 trees were planned to be transplanted and four removed in Jincheng Park, while 81 trees were planned to be transplanted and five removed in Shengmin Park. The report also established post-transplantation survival rate requirements and replacement planting measures in the event that the required survival rates were not achieved. The Court therefore concluded that appropriate mitigation measures for the relevant environmental impacts had been proposed in the EIA Difference Analysis Report.
(2) Based on the foregoing facts and environmental impact assessment results, the Taipei High Administrative Court held that the modifications to the Project did not meet the conditions requiring a new EIA under Article 38, Paragraph 1, Subparagraphs 4 and 5 of the Enforcement Rules of the EIA Act. Accordingly, the competent EIA authority's decision to approve the EIA Difference Analysis Report with revisions was not unlawful.
2. Legal Reasoning of the Supreme Administrative Court
(1) On May 20, 2026, the Supreme Administrative Court rendered Judgment Shang Zi No. 7 of 2026, dismissing the appeal and upholding the lower court's judgment. According to the press release issued by the Supreme Administrative Court, regarding the determination of what constitutes the“implementation of development activities,”the Supreme Administrative Court affirmed the lower court's reasoning that development activities encompass not only actual construction work but also the stages of pre-development planning and post-completion use. Since the archaeological investigation at the Zhanlongshan Archaeological Site was required under the Cultural Heritage Preservation Act to prevent the MRT construction works from interfering with the preservation of the archaeological site, it constituted an indispensable part of the overall development activities. Accordingly, the archaeological investigation conducted by DORTS between September and October 2020 constituted the commencement of substantive construction work, and the Project had therefore been implemented within three years of obtaining the development permit.
(2) As to whether the modifications to the Project required a new EIA, the Supreme Administrative Court also affirmed the lower court's findings. The Court noted that the relocation of LG11 Station to Jincheng Park was intended to improve transfer convenience and avoid the expropriation of private land, while also reducing the area of the park actually occupied by the station. Although the track alignment was changed from a straight section to a curved section, considering the speed of trains entering and leaving the station, the degree of track curvature, and the relevant railway safety measures, there were insufficient grounds to conclude that the modification would increase operational safety risks or adversely affect environmental quality. Accordingly, a new EIA was not required under Article 38, Paragraph 1 of the Enforcement Rules of the EIA Act.
III. Conclusion
According to the Supreme Administrative Court's reasoning, the determination of whether development activities have been implemented within the three-year period prescribed under Article 16-1 of the EIA Act should not be based solely on whether construction of the main project works has commenced. Preliminary activities may also constitute the implementation of development activities if they are legally required, closely connected to the overall development project, and indispensable to subsequent construction works.
Furthermore, modifications to station locations, structures, or track alignments do not automatically trigger the requirement to conduct a new EIA. Rather, the actual impacts before and after the modifications must be specifically assessed, taking into account factors such as land use, environmental quality, safety risks, and mitigation measures.
Developers are therefore advised to maintain comprehensive records of preliminary investigations, construction activities, risk assessments, and comparisons of alternative project designs to substantiate that development activities have commenced and that any subsequent modifications do not meet the threshold requiring a new EIA.
I. Background
The Department of Rapid Transit Systems of the Taipei City Government (the “DORTS”) obtained a development permit on October 25, 2018, for Phase II of the Wanda–Zhonghe–Shulin MRT Line Project (the “Project”). Subsequently, due to modifications to station locations, structural designs, construction plans, the volume of surplus excavated soil, and ancillary MRT facilities, DORTS submitted the Third Environmental Impact Difference Analysis Report (the“EIA Difference Analysis Report”), which was approved with revisions by the competent EIA authority on June 10, 2022.
However, local residents and environmental groups argued that DORTS had not commenced implementation of the Project until more than three years after obtaining the development permit and therefore should have submitted an Environmental Status Difference Analysis and Countermeasure Review Report pursuant to Article 16-1 of the EIA Act. They further contended that the archaeological investigation conducted by DORTS at the Zhanlongshan Archaeological Site in 2020 constituted merely a pre-development environmental survey and could not be regarded as the implementation of development activities.
In addition, they asserted that the relocation of LG11 Station to Jincheng Park, the realignment of the MRT tracks from a straight alignment to a curved alignment, the increase in surplus excavated soil, and the transplantation of vegetation could potentially exacerbate adverse impacts on the surrounding environment. Accordingly, they maintained that a new EIA was required under Article 38, Paragraph 1, Subparagraphs 4 and 5 of the Enforcement Rules of the EIA Act, and consequently initiated administrative litigation.
II. Factual Findings and Legal Reasoning of the Taipei High Administrative Court
1. The “Implementation of Development Activities” under Article 16-1 of the EIA Act Should Be Determined Based on Whether Substantive Construction Work Has Commenced, and the Archaeological Investigation in This Case Constituted Part of the Development Activities
(1) Pursuant to Article 16-1 of the EIA Act, where a developer commences implementation of development activities more than three years after obtaining development approval following the completion of an EIA review, the developer shall submit an Environmental Status Difference Analysis and Countermeasure Review Report to the competent authority for review and shall not commence implementation of the development activities until such review has been completed.
(2) The Taipei High Administrative Court held that whether “development activities have been implemented” should be determined based on whether “substantive construction work has commenced”. The Court further explained that the scope of development activities under the EIA Act encompasses the planning, implementation, and post-completion use of a development project. Accordingly, whether substantive construction work has commenced should be assessed in light of the nature of the development activities and the specific circumstances of each case, applying the rules of experience and logic, rather than solely by reference to whether construction of the main project works has begun.
(3) In the present case, the Court found that the development permit for the Project was issued on October 25, 2018, while the Zhanlongshan Archaeological Site was officially designated as an archaeological site by the New Taipei City Government on March 22, 2019. To accommodate the construction works and comply with archaeological site preservation requirements, DORTS incorporated the archaeological investigation and assessment work into the tender documents and awarded the relevant contract in August 2020. The contractor commenced work on September 10, 2020, and subsequently carried out construction activities on October 31, 2020, including the painting and removal of road markings and the installation of fences and steel guardrails.
(4) The Court further noted that, pursuant to Article 58, Paragraph 2 of the Cultural Heritage Preservation Act, when government agencies formulate plans for major construction projects, they must not interfere with the preservation and maintenance of archaeological sites and must first investigate whether any archaeological sites exist within the project area. Given that the Zhanlongshan Archaeological Site was located along the alignment of the Project, the relevant archaeological investigation was necessary to comply with cultural heritage preservation requirements and to ensure that subsequent construction works could proceed. Accordingly, such investigation should be regarded as an integral and inseparable part of the overall development activities.
(5) Accordingly, the Court held that the archaeological investigation conducted by DORTS at the Zhanlongshan Archaeological Site between September and October 2020 constituted the commencement of substantive construction work for the Project. As the Project had therefore been implemented within three years of obtaining the development permit, DORTS was not required to submit an Environmental Status Difference Analysis and Countermeasure Review Report pursuant to Article 16-1 of the EIA Act.
2. Whether Modifications to a Development Project Require a New EIA Should Be Determined Based on the Actual Environmental Impacts Before and After the Modifications
(1) Pursuant to Article 16 of the EIA Act and Article 38, Paragraph 1 of its Enforcement Rules, where a developer modifies a project that has already passed an EIA review, a new EIA must be conducted for the modified portions if the modifications are likely to exacerbate impacts on the living, natural, or social environment, or on protected objects within the affected area, or adversely affect the maintenance of environmental quality. In determining whether the modifications to the Project would result in increased environmental impacts or adversely affect the maintenance of environmental quality, the Court examined the following aspects:
A. Noise and Vibration Impacts
After reviewing the noise assessment results in the EIA Difference Analysis Report, the Court found that certain predicted noise levels at residential buildings near LG11 Station would exceed the applicable regulatory limits before mitigation measures were implemented. However, DORTS had planned to install four-meter-high double-curved noise barriers and floating slab tracks, and to adjust the track alignment to increase the minimum distance between the outer edge of the elevated structure and nearby residential buildings from 5.46 meters to 6.96 meters. Similar mitigation measures, including noise barriers, floating slab tracks, and track alignment adjustments, were also planned for the section near Tucheng Elementary School. Accordingly, the Court concluded that, following the implementation of these mitigation measures, operational noise levels would comply with the applicable regulatory standards.
In addition, according to the vibration predictions in the EIA Difference Analysis Report, vibration levels at nearby sensitive receptors were estimated to range from approximately 44.0 to 48.1 decibels, below both the human perception threshold of 55 decibels and the applicable vibration assessment standards. The anticipated vibration impacts were therefore considered minor.
B. Use of Jincheng Park and Safety Risks Associated with the Curved Track Alignment
The Court found that the relocation of LG11 Station to Jincheng Park was primarily intended to avoid the expropriation of private land and improve the convenience of transfers to the Bannan Line. According to the area occupied by park facilities as calculated in the EIA Difference Analysis Report, the area would decrease from approximately 1,482 square meters before the modification to 434 square meters after the modification. Furthermore, the new station would adopt an elevated structure, allowing the space beneath the station to remain available for public recreational use. Accordingly, the Court rejected the plaintiffs' argument that the area of the park occupied by the station should be calculated based on the entire projected footprint of the station structure.
Regarding safety concerns arising from the change in track alignment from a straight section to a curved section, the Court noted that the purpose of an EIA is to assess whether the impacts of development activities on the surrounding environment can be adequately controlled, rather than to regulate the inherent risks associated with construction projects. The Court further considered that trains entering and leaving LG11 Station would travel at approximately 20 kilometers per hour, that derailment protection curbs would be installed along both sides of the tracks, and that the MRT system would be equipped with a train monitoring system and an Automatic Train Protection (“ATP”) system capable of automatically reducing train speeds on curves or initiating emergency braking in the event of overspeeding. Accordingly, the Court found insufficient grounds to conclude that the modified track alignment would give rise to a high risk of derailment.
C. Increase in Surplus Excavated Soil and Transportation Impacts
In this case, due to the conversion of certain elevated sections and stations into underground structures, the estimated volume of surplus excavated soil increased from approximately 240,000 cubic meters to 760,000 cubic meters.
The Court reviewed the surplus soil transportation plan set out in the EIA Difference Analysis Report, including measures such as scheduling transportation during off-peak hours, using national highways, expressways, and suburban roads, and adjusting actual transportation routes in accordance with the instructions of the competent transportation authorities. The Court concluded that, despite the increase in the volume of surplus excavated soil, there were insufficient grounds to determine that such increase would exacerbate impacts on the surrounding living environment or adversely affect the maintenance of environmental quality.
D. Addition of a Substation and Transplantation of Vegetation
Regarding the addition of a main substation in Shengmin Park in Shulin District, the Court found that the substation constituted an ancillary facility of the MRT system. As its planned supply voltage was 161 kilovolts, it did not exceed the threshold of 161 kilovolts for land-based power facilities under the EIA screening criteria applicable at the time. Accordingly, the addition of the substation did not independently trigger the requirement to conduct an EIA.
With respect to the impacts on vegetation in Jincheng Park and Shengmin Park, the Court found that the affected vegetation primarily consisted of commonly planted tree species, with no rare or endangered plant species involved. The EIA Difference Analysis Report had proposed transplantation and replacement planting measures for the affected trees. Specifically, 120 trees were planned to be transplanted and four removed in Jincheng Park, while 81 trees were planned to be transplanted and five removed in Shengmin Park. The report also established post-transplantation survival rate requirements and replacement planting measures in the event that the required survival rates were not achieved. The Court therefore concluded that appropriate mitigation measures for the relevant environmental impacts had been proposed in the EIA Difference Analysis Report.
(2) Based on the foregoing facts and environmental impact assessment results, the Taipei High Administrative Court held that the modifications to the Project did not meet the conditions requiring a new EIA under Article 38, Paragraph 1, Subparagraphs 4 and 5 of the Enforcement Rules of the EIA Act. Accordingly, the competent EIA authority's decision to approve the EIA Difference Analysis Report with revisions was not unlawful.
2. Legal Reasoning of the Supreme Administrative Court
(1) On May 20, 2026, the Supreme Administrative Court rendered Judgment Shang Zi No. 7 of 2026, dismissing the appeal and upholding the lower court's judgment. According to the press release issued by the Supreme Administrative Court, regarding the determination of what constitutes the“implementation of development activities,”the Supreme Administrative Court affirmed the lower court's reasoning that development activities encompass not only actual construction work but also the stages of pre-development planning and post-completion use. Since the archaeological investigation at the Zhanlongshan Archaeological Site was required under the Cultural Heritage Preservation Act to prevent the MRT construction works from interfering with the preservation of the archaeological site, it constituted an indispensable part of the overall development activities. Accordingly, the archaeological investigation conducted by DORTS between September and October 2020 constituted the commencement of substantive construction work, and the Project had therefore been implemented within three years of obtaining the development permit.
(2) As to whether the modifications to the Project required a new EIA, the Supreme Administrative Court also affirmed the lower court's findings. The Court noted that the relocation of LG11 Station to Jincheng Park was intended to improve transfer convenience and avoid the expropriation of private land, while also reducing the area of the park actually occupied by the station. Although the track alignment was changed from a straight section to a curved section, considering the speed of trains entering and leaving the station, the degree of track curvature, and the relevant railway safety measures, there were insufficient grounds to conclude that the modification would increase operational safety risks or adversely affect environmental quality. Accordingly, a new EIA was not required under Article 38, Paragraph 1 of the Enforcement Rules of the EIA Act.
III. Conclusion
According to the Supreme Administrative Court's reasoning, the determination of whether development activities have been implemented within the three-year period prescribed under Article 16-1 of the EIA Act should not be based solely on whether construction of the main project works has commenced. Preliminary activities may also constitute the implementation of development activities if they are legally required, closely connected to the overall development project, and indispensable to subsequent construction works.
Furthermore, modifications to station locations, structures, or track alignments do not automatically trigger the requirement to conduct a new EIA. Rather, the actual impacts before and after the modifications must be specifically assessed, taking into account factors such as land use, environmental quality, safety risks, and mitigation measures.
Developers are therefore advised to maintain comprehensive records of preliminary investigations, construction activities, risk assessments, and comparisons of alternative project designs to substantiate that development activities have commenced and that any subsequent modifications do not meet the threshold requiring a new EIA.
