The sanitary sewer line drains toilet waste, washing machines, floor drains and bathtub drains to the sanitary sewer main in the street. The waste requires treatment prior to discharge and is transported to the Metropolitan Water Reclamation District for Greater Chicago (MWRDGC) sewer. Downspouts, footing drains, and sump pumps handle clean storm water and groundwater.
Storm Sewer Sump
The storm sewer sump pumps rainwater collected under the basement floor pad to the rear yard. If the discharge of the storm sewer pump isn't far enough away from the house, water discharged from the basement will collect against the foundation wall or footing and seep into the footing drains. Therefore, it is recommended that the discharge is located at least five feet away from the house. Additionally, it is recommended that storm water be discharging to flow overland to allow water to infiltrate into the soil, reducing the cost of pumping and treating additional water collected in the storm sewer.
The sanitary ejector pumps waste water from toilets, floor drains, washing machines and bathtubs to the private sanitary service line. The private sanitary service is connected to the village owned sanitary sewer property line. The sanitary pump is necessary to pump any wastewater from the lower levels (below grade) out of the house. If a residence does not have a basement, or has only a crawl space, a sanitary pump is usually not required. All wastewater from fixtures located at an elevation above the sanitary service line do not require a pump.
A sump is installed under the basement floor to intercept sewage flowing from basement fixtures and the basement floor drain. An ejector pump in the sump pushes sewage up above the flood level. From there it can drain by gravity into the sewer service line. Plumbing fixtures on the first floor continue to drain by gravity to the service line. It is unlikely that the sewers will back up above ground level. If water does go higher, a check valve in the pipe from the ejector pump keeps it in the pipes. Backed up sewage is enclosed in the sewer pipes so there is no worry about overflowing laundry tubs or basement toilets.
During a power outage, the ejector pump won’t work. But this only limits the use of the facilities in the basement that need the pump.
If the storm water sump is connected to the private sanitary sewer rather than discharging water from the footing drains to the yard, the sanitary sewer can fill up with storm water. The sanitary sewer was not sized to handle the additinal flow from the footing drains. Therefore, sanitary backups in homes and manholes may result.
Other examples of illegal connections to sanitary sewer include:
- Patio drains
- Rear yard drains
- Removing covers off sanitary sewer manholes