FAQs on CSOs Attachments Document City of Upper Sandusky CSO Notification Plan (1.23 MB) Document 2020 City of Upper Sandusky Annual CSO Notification Report (132.05 KB) Document 2022 City of Upper Sandusky Annual CSO Notification Report (136.54 KB) 2023 CSO REPORTS 2022 CSO REPORTS 2021 CSO REPORTS 2020 CSO REPORTS 2019 CSO REPORTS 2018 CSO REPORTS