The CSO outfalls are mapped on this web page with pushpins at each the CSO outfall locations to indicate the status of the outfall discharge. The information on the map is updated using a model to anticipate the quantity of rainfall that will trigger each CSO. The model was developed using U.S. EPA’s Storm Water Management Model (SWMM). Real time rainfall data are taken from the weather station at the Metropolitan Syracuse Wastewater Treatment Plant (Metro) and are compared to the trigger values in the model to estimate where and when overflows are likely occurring. Weather station information is transmitted hourly. Should the hourly rainfall meet or surpass the CSO trigger, the outfall will be represented as discharging.
When a combined sewer overflow (CSO) is occurring, and up to a period of approximately 48-hours following the rainfall event, bacteria levels increase and water quality in Onondaga Creek, Harbor Brook, and Ley Creek. Bacteria levels in portions ofOnondagaLaketypically increase after significant storm events, primarily in the southern end of the lake where most tributaries receiving CSOs are located.
The pushpins will change color according to the likelihood of CSO pollution as follows:
- On a dry day, the pushpins designating CSO outfalls will be green, signifying that a CSO event is highly unlikely.
- When the rainfall is sufficient to have reached sewer capacity and is estimated to cause a CSO event, the pushpins will turn red. After 24 hours have passed since the CSO event, the pushpin will be yellow, signifying that there is a moderate risk of elevated bacteria levels.
- After 48 hours have passed and it is unlikely that the bacteria levels are elevated due to CSO discharges, the pushpins will turn green, once again.
Please be advised that the information in this website is a predictive system based on a mathematical model, not data collected from actual water quality samples. The Department has been conservative in estimating the probability of combined sewer overflow events occurring. The Onondaga County Department of Water Environment Protection will also use this site to alert the public of sanitary sewer overflows, sewer maintenance operations, or other conditions that may impact water quality.