DirtyWaterWatch Public waters. Public record.

Connecticut / Sewer operators /

Groton, City of

Sewer utility · Connecticut

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.

No outlet locations are in our records for this operator. Square boat markers mark boat launches listed by OpenBoatLaunch.

Federal wastewater discharge permit (NPDES)
not recorded
Wastewater outlets
None with locations in our records
Waters listed as receiving wastewater
not recorded
Tracked waters
Thames River, CT, Birch Plain Creek, CT
Discharge records counted
37 records · latest
Total reported volume in these records
5,600 gallons across the 18 records that give a volume (19 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 2026-11-03 14:48 UTC.

Public notices and alerts

We do not list an alert service for this operator yet. Check its website.

Source: Groton, City of's public notice and alert pages and the state's notification records.

Report a missing notice or error

Wastewater outlets

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

Reports and advisories

Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater.

Reports linked to Groton, City of, newest first
WhenReportStatus
to 8:45 AMWater not mapped · Manhole, Three Acre Rd, Groton, CT · SSO · 10 gallons report · notice · mapended
to 5:30 AMWater not mapped · Manhole, 5 Riverview Ave, Groton, CT · SSO (earlier version) · 180 gallons in all ended
to 4:45 AMWater not mapped · Manhole, 5 Riverview Ave, Groton, CT · SSO (earlier version) · 300 gallons in all ended
to Dec 12 ’24, 2:30 PMWater not mapped · Pump Station, 5 Beach Pond Rd, Groton, CT · SSO · 25 gallons report · noticeended
to 9:30 PMWater not mapped · Manhole, 7 Eastern Point Rd, Groton, CT · SSO · 30 gallons report · noticeended
to 1:30 PMWater not mapped · Sewer Main, 197 Shore Ave, Groton, CT · SSO · 300 gallons report · noticeended
to Nov 7 ’24, 11:30 AMWater not mapped · Manhole, 107 Spicer Ave, Groton, CT · SSO · 30 gallons report · noticeended
to 9:15 AMThames River · Pump Station, 51 Fairview Ave, Groton, CT · SSO · 630 gallons report · notice · mapended
to 12:30 PMWater not mapped · Pump Station, 149 Nathan Hale Rd, Groton, CT · SSO · 330 gallons report · noticeended
to 2:30 AMBirch Plain Creek · Manhole, 149 Madison Pl, Groton, CT · SSO · 250 gallons report · notice · mapended
to 5:45 PMWater not mapped · Manhole, 79 Litton Ave, Groton, CT · SSO · “5-10 gallons” report · noticeended
to 7:30 PMWater not mapped · Basement, 378 CT-349, Groton, CT · SSO · “Less than 10 gallons total” report · noticeended
to 3:15 PMWater not mapped · Manhole, 1 Bishop Ln, Groton, CT · SSO · 75 gallons report · noticeended
to 8:30 PMWater not mapped · Pump Station, Fairview Ave · SSO · volume in each report ended
to 3:00 PMBirch Plain Creek · Manhole, Madison PL · SSO · volume in each report mapended
to 11:30 AMWater not mapped · Manhole, Bishop Lane City of Groton · SSO · volume in each report ended

Sources: CT DEEP CSO/SSO Performance Dashboard (QScend), retrieved 2026-11-02 11:20 UTC; CT DEEP Sewage Right-to-Know annual report 2024, retrieved 2026-11-03 14:32 UTC; CT DEEP reporting archive 2016-2021, retrieved 2026-11-03 14:38 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 41 records.See them all with filters.

All reports in Connecticut by year: 2026 (1 from Groton, City of) · 2025 (6 from Groton, City of) · 2024 (6 from Groton, City of) · 2023 (1 from Groton, City of) · 2022 (2 from Groton, City of) · 2021 (11 from Groton, City of) · 2020 (4 from Groton, City of) · 2019 (2 from Groton, City of) · 2018 (4 from Groton, City of) · 2017 (3 from Groton, City of) · 2016 (1 from Groton, City of)

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 2026-11-03 14:48 UTC.

Reported discharges over time

  • Discharges reported by Groton, City of, last 12 months1December 2025 to November 2026Verified reports where available, else notices; revisions and duplicates counted once.
  • Days with a discharge reported by Groton, City of, last 12 months1December 2025 to November 2026A day counts once however many discharges were under way on it. Verified reports where available, else notices; revisions and duplicates counted once.
  • Hours with a discharge or advisory status from Groton, City of's reports, last 12 months0December 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 (Groton, City of)0.0%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.

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system. 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. Outfall: a pipe or outlet where wastewater enters a water body.

Reported discharges per month

12 reported discharges, January 2022 to November 2026.

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

Connecticut dashboard records begin December 2, 2021; annual-report rows that repeat a dashboard record are counted once. Connecticut's Sewage Right-to-Know annual reports cover January 1, 2021 to November 3, 2026.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports. Records cover January 1, 2022 to November 3, 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. Connecticut dashboard records begin December 2, 2021; annual-report rows that repeat a dashboard record are counted once. Connecticut's Sewage Right-to-Know annual reports cover January 1, 2021 to November 3, 2026. Connecticut's reporting archive runs from July 4, 2016 to December 2, 2021.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table

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.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports. Records cover January 1, 2022 to November 3, 2026.

Show table

Reported discharges per year, 2016 to 2026

37 reported discharges, 2016 to 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other
  • Incomplete source coverage

Connecticut dashboard records begin December 2, 2021; annual-report rows that repeat a dashboard record are counted once. Connecticut's Sewage Right-to-Know annual reports cover January 1, 2021 to November 3, 2026. Connecticut's reporting archive runs from July 4, 2016 to December 2, 2021.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table

Reported volume per year

Gallons (axis: K thousand, M million), summed from the 18 reports that gave a volume as a number (19 did not).

  • Incomplete source coverage

19 of 37 discharge reports gave no volume as a number (17 gave a range); only numbers are summed. Some volumes in Connecticut's annual reports are given as text or ranges and are not summed. Connecticut's 2016 to 2021 archive gives volumes as ranges ("20,001 - 50,000 gallons"); they are not summed.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table

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
  • Incomplete source coverage

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.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table

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
  • Season with incomplete source coverage

Seasons with incomplete source coverage: 2016. The share is of the hours a source covered. 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.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 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.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table

Reported discharges by wastewater outlet

Wastewater outlets with the most tracked discharge records: 10 of 27, all years. Counts depend on reporting coverage and do not measure legal compliance or harm.

Connecticut dashboard records begin December 2, 2021; annual-report rows that repeat a dashboard record are counted once. Connecticut's Sewage Right-to-Know annual reports cover January 1, 2021 to November 3, 2026. Connecticut's reporting archive runs from July 4, 2016 to December 2, 2021.

Sources: Connecticut Department of Energy and Environmental Protection sewage overflow dashboard; Connecticut Sewage Right-to-Know annual reports; Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021. Records cover July 4, 2016 to November 3, 2026.

Show table
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.

  • Connecticut Department of Energy and Environmental Protection sewage overflow dashboard: records from December 2, 2021 to the latest update
  • Connecticut Sewage Right-to-Know annual reports: records from January 1, 2021 to the latest update
  • Connecticut Department of Energy and Environmental Protection reporting archive, 2016 to 2021: records from July 4, 2016 to December 2, 2021