Retention Basin/Combined Sewer/Sanitary Sewer Overflow

Combined Sewer Overflows (CSOs): Discharge of a mixture of storm water and domestic waste when the flow capacity of a sewer system is exceeded during rainstorms.  

Sanitary Sewer Overflows (SSOs): are discharges of raw sewage from municipal sanitary sewer systems. SSOs can release untreated sewage into basements or out of manholes and onto city streets, playgrounds and into streams before it can reach a treatment facility. SSOs are often caused by blockages in sewer lines and breaks in the sewer lines.