NS 2023 Annual Report For EPA

• IBM Index Class Name: Hydrology
• Doc Date: 8/28/2025
• Archive: No

Natural Soda LLC 2023 Project Status Report & Annual Plan of Development
13 January 2024

3.2.5. EPA Notification – Schedule of Planned SSMW Logging
(GR/CCL) (Confidential)
• Per EPA UIC Permit C030358-00000 requirements; routine subsurface
subsidence monitor well (SSMW) logging (GR/CCL) is planned for 2024 or
the first quarter of 2025:
o NS logged the DS-3 well on January 9, 2024 to collect SSMW CCL/GR
logs. The DS-3 monitor well serves as a GMW and SSMW for the 12H
and 13H mining intervals. Comparison of 2002, 2011 and 2024 CCL/GR
logs indicated no subsurface subsidence in the DS-3 well.
o Per UIC Permit, SSMW logging is determined based on mining interval
production, NS will notify the EPA of upcoming SSMW logging as
production milestones become more clear.