A category 2 SSO is:

A category 2 Sanitary Sewer Overflow (SSO) is defined as any overflow that does not reach surface waters, which typically means it may occur on private property or within the sewer system itself. However, within the framework of categorizing SSOs, the distinction of category 2 specifically refers to overflows that are significant but not as severe as category 1 SSOs, which involve discharges that do reach surface waters and present a higher risk to public health and the environment.

This definition clarifies that category 2 SSOs, while potentially harmful, are of a less critical nature than category 1. They are indeed still important from a reporting and maintenance standpoint, but do not carry the same immediate risks associated with public exposure and environmental impact like those designated as category 1. Category 2 implies that while the event is concerning, it is distinguishable and manageable through appropriate reporting and operational procedures.

Understanding this categorization is crucial for wastewater operators and stakeholders in managing system integrity, ensuring compliance with environmental regulations, and planning preventive measures to minimize the risk of future overflow incidents.