Public Open House (3rd Event) for the Demonstration Test of the Project “Development of A‑ERW (Advanced Enhanced Rock Weathering) Utilizing Rock and Site Characteristics” at the Amemasu River and Orido River Sites in Shikabe, Hokkaido
Background
This technology promotes the natural weathering of rocks as a means of removing carbon dioxide from the atmosphere. In 2026, the Japan Enhanced Rock Weathering Technology Collaborative Innovation Partnership (J-ERW) was established to advance research and development aimed at standardizing evaluation methodologies (carbon accounting) and measurement, reporting, and verification (MRV) systems suited to Japan’s geological and resource conditions. As a result, the technology has entered the stage of practical implementation.
This demonstration project has been carried out continuously with the understanding and cooperation of the residents and municipal government of Shikabe Town. The present event was organized as a site visit for local residents. Public open houses have been held annually since FY2024, and this year marks the third event.
Date and Schedule
Sunday, August 23, 2026
Morning Session
- 10:00 a.m. Meet in front of Shikabe Town Hall and travel to the former Amemasu River mine portal
- 10:40 a.m. Overview of the demonstration project (from the mine portal to Point A on the Orido River)
- 12:00 p.m. Dismissal at Shikabe Town Hall
Afternoon Session
- 1:00 p.m. Meet in front of Shikabe Town Hall and travel to the former Amemasu River mine portal
- 1:40 p.m. Overview of the demonstration project (from the mine portal to Point A on the Orido River)
- 3:00 p.m. Dismissal at Shikabe Town Hall
Number of Participants
- Morning session: 4 participants
- Afternoon session: 2 participants
- Total: 6 participants
Overview of the Site Visit
The weather was favorable, with little chance of rain despite the lingering summer heat. After gathering at Shikabe Town Hall, participants traveled by vehicle, with support from the Town Hall, to the portal of the former Shojingawa Mine.
Although the mine entrance has been sealed, strongly acidic groundwater continues to flow from the portal. A plastic barrel was temporarily installed downstream of the discharge point, into which powdered scallop shells (Hotacal), produced in Shikabe and composed primarily of calcium carbonate, were added and mixed. The resulting slurry was then pumped into the river (Photo 1).
Photo 1. Former Nakagiri Portal of the Shojingawa Mine and Experimental Equipment Setup
Scallop shell powder was used instead of basalt powder in this experiment to investigate both the potential for carbon dioxide removal after calcium reaches the ocean and the neutralization of acidity in the river. The findings will provide valuable baseline information for identifying optimal combinations of scallop shell and basalt materials in future applications. The experimental setup and work plan were carefully designed and implemented by a student team led by Hokkaido University.
At the site, Professor Sato explained the theoretical basis of carbon dioxide removal by enhanced rock weathering, as well as recent developments surrounding the technology, including carbon markets and emissions trading schemes, and discussed future prospects for its deployment.
Participants raised a variety of questions, including the causes and effects of the reddish-yellow discoloration of the water resulting from iron precipitation after material addition, methods for measuring application rates and carbon dioxide removal, and other technical aspects of the project. These questions led to lively discussions and exchanges of ideas (Photos 2 and 3).
Among the topics that generated the greatest interest was the hope that fish populations might eventually return to the Amemasu River and Orido River, where fish are currently absent. Participants shared local knowledge, noting that salmon still migrate upstream in tributaries unaffected by the mine drainage and suggesting that the river’s name, “Amemasu (trout) River,” reflects the abundance of fish in the past.
The participants also provided valuable historical insights into the relationship between the railway and mining activities that continued until the late 1940s, offering an important perspective on the local community and its history.
In the middle reaches of the river, participants observed sampling activities and pH measurements conducted by students from Waseda University (Photo 3), helping them gain a broader understanding of the overall demonstration project.
Many participants expressed surprise that the experiment was being conducted under such challenging conditions in the mountains. They also praised the dedication and hard work of the students carrying out the field research.
In addition to these annual public open houses, explanatory meetings are held at the end of each fiscal year with representatives of the local fisheries cooperative, chamber of commerce, and other key stakeholders in Shikabe Town. Through these ongoing opportunities for communication and dialogue, we will continue exploring ways for the project and the local community to coexist and prosper together.
Photo 2. Explanation for Local Residents (Near the Riverbank)
Photo 3. Explanation for Local Residents (Rock Material Application in the Forest Area)
Photo 4. Explanation at the Confluence of the Shojingawa and Amemasu Rivers (Water Quality Monitoring)
Written and photographed by:
Yoshihito Takeda (Hokkaido University)
Public Relations Officer, J-ERW