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Michigan / Sewer operators /

City of Bay City

Sewer utility with combined sewers · Michigan · Bay City

Map sources: water outlines and launches from OpenBoatLaunch and OpenStreetMap contributors (Open Database License); wastewater outlets from EPA and state records; downstream estimates by DirtyWaterWatch using U.S. Geological Survey maps and flow data. Base map: OpenFreeMap and OpenMapTiles.

Solid dots mark combined sewer outfalls. Ringed dots mark treatment plant outfalls. Dashed river stretches are estimates of where a discharge travels. Square boat markers mark boat launches listed by OpenBoatLaunch.

Federal wastewater discharge permit (NPDES)
MI0022284
Wastewater outlets
5 combined sewer outfalls and 3 treatment plant outfalls listed by EPA or state agencies · List
Waters listed as receiving wastewater
SAGINAW RIVER; Saginaw River
Tracked waters
Saginaw River, MI
Discharge records counted
329 records · latest
Total reported volume in these records
5,511,230,500 gallons across the 327 records that give a volume (2 without one)

These totals reflect the records we track. Missing volumes and gaps in reporting limit comparisons between operators.

Sources: EPA ECHO and the operator and state sources linked below. Counts use the discharge records on this page. Updated 2026-11-05 01:25 UTC.

Public notices and alerts

Pages where City of Bay City or the state publishes its notices (check them for an alert sign-up):

Its public-notice channels

Source: City of Bay City's public notice and alert pages and the state's notification records; DirtyWaterWatch register of public-notice channels and its page monitor.

Report a missing notice or error

Rain and discharges

The NOAA MRMS radar-only rainfall estimate for the 24 hours to the latest hour, read every hour at each outfall from the radar grid. We show a caution when the rain reaches the amount below and no discharge report has arrived.

Threshold
0.1 in of rain in 24 hours (site default: This site's default: 0.1 inch of rain in 24 hours at a combined sewer outfall, applied where the state publishes no rain trigger of its own)
Radar now
2 in in the 24 hours to Nov 4, 2026, 7:00 PM EST
Forecast
0.03 in forecast in the next 24 hours (NWS forecast issued Nov 4, 2026, 3:49 PM EST)
Status
Discharge possible: heavy rain, no report received

Source: NOAA National Weather Service, MRMS radar-only rainfall estimate, valid Nov 4, 2026, 7:00 PM EST, retrieved 2026-11-05 01:19 UTC; threshold: site default; rule: How it works, discharge likely or possible.

Wastewater outlets

Outfall: a pipe or outlet where wastewater enters a water body.

5 combined sewer outfalls and 3 treatment plant outfalls listed by EPA or state agencies.

Combined sewer outfalls

5 outfalls

Source: U.S. Environmental Protection Agency (EPA) national combined sewer outfall inventory (ECHO) and state outfall layers. Open or closed as EPA's inventory lists it. DirtyWaterWatch links outlets to waters using permit numbers, locations and names.

Treatment plant outfalls

3 outfalls

Source: U.S. Environmental Protection Agency (EPA) permit records (ICIS-NPDES permitted features): where a treatment plant’s permitted discharge leaves. No national source says whether a plant outfall is open or closed.

Reports and advisories

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system.

Reports linked to City of Bay City, newest first
WhenReportStatus
to 8:00 AMSaginaw River · 040 · CSO · 30.6 million gallons in all mapended
to 5:45 AMSaginaw River · 014 · CSO · 7.6 million gallons in all mapended
to Apr 16, 7:30 AMSaginaw River · 013b · CSO · 101.6 million gallons in all mapended
to Apr 5, 3:30 AMSaginaw River · 014 · CSO · 23 million gallons in all mapended
to Apr 5, 6:00 AMSaginaw River · 013b · CSO · 18.3 million gallons report · notice · mapended
to Apr 7, 5:00 AMSaginaw River · 048 · CSO · 105.7 million gallons report · notice · mapended
to Apr 4, 2:30 PMSaginaw River · 040 · CSO · 23.3 million gallons report · notice · mapended
to Mar 17, 10:30 AMSaginaw River · 048 · CSO · 15.7 million gallons report · notice · mapended
to 7:30 PMSaginaw River · 014 · CSO · 3.3 million gallons report · notice · mapended
to Mar 14, 4:00 AMSaginaw River · 048 · CSO · 58.6 million gallons report · notice · mapended
to 6:30 PMSaginaw River · 013b 013b · CSO · 500,000 gallons report · notice · mapended
to Apr 3 ’25, 5:15 AMSaginaw River · 040 040 · CSO · 2.1 million gallons report · notice · mapended
to Apr 3 ’25, 8:00 AMSaginaw River · 013b 013b · CSO · 4.2 million gallons report · notice · mapended
to Apr 6 ’25, 12:50 AMSaginaw River · 048 048 · CSO · 84.7 million gallons report · notice · mapended
to Dec 31 ’24, 8:30 AMSaginaw River · 048 048 · CSO · 42.1 million gallons report · notice · mapended
to Mar 16 ’24, 8:45 AMSaginaw River · 048 048 · CSO · 21.4 million gallons report · notice · mapended
to Feb 2 ’24, 1:00 AMSaginaw River · 048 048 · CSO · 6.7 million gallons report · notice · mapended
to Jan 28 ’24, 6:00 AMSaginaw River · 048 Outfall 048 · CSO · 14.3 million gallons report · notice · mapended
to Aug 18 ’23, 10:00 AMSaginaw River · 048 048 · CSO · 23.7 million gallons report · notice · mapended
to Aug 7 ’23, 6:00 PMSaginaw River · 048 Rtb 5 · CSO · 37.4 million gallons report · notice · mapended

Sources: EGLE MiEnviro CSO/SSO List, retrieved 2026-11-05 01:07 UTC. A report's record id and times show when you hover or focus its "report" link.

Download these reports as CSV

Showing the latest 25 records of 329 records.See them all with filters.

All reports in Michigan by year: 2026 (15 from City of Bay City) · 2025 (4 from City of Bay City) · 2024 (4 from City of Bay City) · 2023 (13 from City of Bay City) · 2022 (3 from City of Bay City) · 2021 (2 from City of Bay City) · 2020 (5 from City of Bay City) · 2019 (12 from City of Bay City) · 2018 (11 from City of Bay City) · 2017 (18 from City of Bay City) · 2016 (5 from City of Bay City) · 2015 (13 from City of Bay City) · 2014 (13 from City of Bay City) · 2013 (21 from City of Bay City) · 2012 (11 from City of Bay City) · 2011 (13 from City of Bay City) · 2010 (2 from City of Bay City) · 2009 (25 from City of Bay City) · 2008 (30 from City of Bay City) · 2007 (7 from City of Bay City) · 2006 (21 from City of Bay City) · 2005 (16 from City of Bay City) · 2004 (19 from City of Bay City) · 2003 (9 from City of Bay City) · 2002 (22 from City of Bay City) · 2001 (15 from City of Bay City)

Other sewer operators on these waters

The last 90 days

Last 90 days, hour by hour. Red: discharge or advisory reported. Amber: caution. Hatched amber: end not confirmed. Plum: algal bloom advisory. Red or amber with a light line inside: beach advisory or caution. Dotted: monthly report (days with discharge, dates not given). Grey: no current status on the water outline. Purple hatching: source update overdue.

No discharge, advisory or caution periods are shown for the waters this sewer operator's reports were placed on in this time span. Check downstream stretches and source coverage.

Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-05 01:25 UTC.

Reported discharges over time

  • Discharges reported by City of Bay City, last 12 months15December 2025 to November 2026Verified reports where available, else notices; revisions and duplicates counted once.
  • Days with a discharge reported by City of Bay City, last 12 months17December 2025 to November 2026A day counts once however many discharges were under way on it.
  • Hours with a discharge or advisory status from City of Bay City's reports, last 12 months316December 2025 to November 2026Red hours by the map's rules: each discharge to its reported end plus the state's post-discharge period; overlapping hours count once.
  • 2026 season with a discharge or advisory status (City of Bay City)0.5%May to October 2026Share of May 1 to October 31 hours with red status by the map's rules, of the hours a source covered.

Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater. Treatment bypass: wastewater skips one or more treatment steps. Blended discharge: wastewater that skipped some treatment is mixed with treated wastewater.

Reported discharges per month

39 reported discharges, January 2022 to November 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2022 to November 4, 2026.

Show table

Hours with a discharge or advisory status per month

Hours when a water had a discharge or advisory status from this sewer operator's reports, under DirtyWaterWatch rules.

  • Discharge or advisory reported

9 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 1 discharge reported to last more than 31 days is counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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Days with a reported discharge per month

A day counts when any counted discharge was under way on it, from its start to its reported end in Eastern Time; a report with no end counts its start day.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2022 to November 4, 2026.

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Reported discharges per year, 2001 to 2026

329 reported discharges, 2001 to 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

Show table

Reported volume per year

Gallons (axis: K thousand, M million), summed from the 327 reports that gave a volume as a number (2 did not).

2 of 329 discharge reports gave no volume as a number; only numbers are summed.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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Hours with a discharge or advisory status per year

Hours with a discharge or advisory status each year under DirtyWaterWatch rules; 2026 to date.

  • Discharge or advisory reported

9 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 1 discharge reported to last more than 31 days is counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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Share of the May to October season with a discharge or advisory status

Share of the hours from May 1 to October 31 with a discharge or advisory status under DirtyWaterWatch rules.

  • Discharge or advisory reported

9 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 1 discharge reported to last more than 31 days is counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

Show table

Reported discharges by calendar month, all years

Every counted discharge report, by the calendar month it began.

Months are summed over every year a tracked source covers; the table gives the number of years behind each month.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

Show table

Reported discharges by wastewater outlet

Wastewater outlets with the most tracked discharge records: 10 of 10, all years. Counts depend on reporting coverage and do not measure legal compliance or harm.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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How these charts are counted

We count each discharge once. Where a source publishes notices and confirmed reports, we use confirmed reports for an operator's month when available; otherwise we use notices. We combine revisions and exclude duplicate state reports copied by the U.S. Environmental Protection Agency (EPA). Monthly and yearly totals appear separately. Status hours follow this site's rules. Shaded gaps mean missing coverage, not zero discharges.

  • mi-egle-mienviro-cso-sso-list: records from January 1, 2001 to the latest update