DEEP Reminds Residents About Water Quality Impacts, Water Safety Following Heavy Rainfall Events

(HARTFORD)--With the prolonged period of heavy rainfall occurring across the state, the Connecticut Department of Energy and Environmental Protection (DEEP) reminds residents about impacts to water quality following such events, and safety precautions to take.

Water Quality Impacts During and After the Storm

Swimming and Recreation

Do not swim or recreate in any waters which are not designated and open for swimming. Runoff flowing into the state’s waterbodies, during and after a storm can carry pollutants including bacteria, metals, solids, and oil/greases.
CT DEEP conducts weekly bathing water sampling at state-owned and managed swimming areas. Water testing results are found at: Swimming Water Quality Report | Connecticut State Parks and Forests. Additionally, towns/cities with local beaches also monitor water quality to assure safety. Check local websites for more information.
Information on whether waters are swimmable or boatable can also be found at: Is It Clean

Combined Sewer Overflows (CSOs)

CSOs are legacy drainage systems from the late 1800s/early 1900s. Back then, the best practice was to collect wastewater and rainwater together in one pipe and discharge it to a waterbody, away from inhabitants. This practice was designed to protect human health and property from sewer backups and also to protect wastewater treatment facilities (WWTF) from long-term damage from flooding/inundation.
Under most conditions, combined systems send wastewater to a treatment facility before discharge to a waterbody. However, during periods of heavy rain, CSOs are activated and discharge untreated wastewater (a combination of sewage mixed with rainwater) to water bodies.
Connecticut has 1 community (Metropolitan District Commission/City of Hartford) with CSOs to the Connecticut River. Connecticut’s 3 other CSO communities (Norwich, Bridgeport, New Haven) discharge to the Long Island Sound.
Massachusetts has 3 communities which discharge CSOs to the Connecticut River (Chicopee, Holyoke, Springfield)
During and within 48-72 hrs of rain events, the Connecticut River and the Long Island Sound may see elevated health risk and environmental impact due to presence of bacteria, solids, other pollutants related to CSOs.
While the human health risk in the Connecticut River and the Sound isn’t significant after rain events, the water quality impact is significant. CSOs degrade water quality and designated uses for water bodies (such as recreation and fishing)
Past the 48-72-hour period, the increased health risk diminishes because:
- CSOs discharges are diluted by rainwater and increased flow moves through the Connecticut River and the Sound quickly.
- The Connecticut River and the Sound are large waterbodies with good mixing on dry days. During wet periods, when the flow levels and volumes are higher due to rainwater runoff/drainage from land, the volume and mixing level increases.
Public information related to CSOs
- For Connecticut’s CSOs, refer to CT DEEP Performance Dashboard. Also, look out for physical CSO signs near discharge pipes along waterbodies.
- For Massachusetts CSOs, notifications are available:
https://springfieldalerts.com/
https://chicopeema.gov/936/Combined-Sewer-Overflow-Public-Notificat
https://www.holyoke.org/dpw-sewer-and-waste-water/

Dam Safety

Do not swim or come in contact with dam structures and water upstream or downstream of the dam. Swimming or recreating in waters during high flow rainfall events is very dangerous During and after rainfall, waters are turbulent and dangerous.
Watch on YouTube Low-head Dams: Get Out and Scout (PSA)
Dam owners are solely responsible for maintaining their dams and keeping them safe. Dam owners should inspect their dams to ensure dams are functioning properly and to assess and address impacts to dams from the storm.

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Contact

DEEP Communications
DEEP.Communications@ct.gov
860-424-3110

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