Controlling sewage that gets washed into local waterways when it rains is critical to protecting water quality. Rainwater flows down storm drains, carrying pollution from the streets, and if it is a heavy rain, causes sewage to overflow into rivers, lakes and streams.
Sewer overflows, especially from combined sewer systems that carry sewage from buildings and storm water from street drains, are a major environmental problem. The U.S. Environmental Protection Agency (EPA) has prepared an important report to answer commonly asked questions about combined sewer overflows.
Many of the sewer systems in New York and New Jersey and some in Puerto Rico are combined systems that carry sewage from homes and businesses as well as rainwater collected from street drains. When they overflow during heavy rains, the rainwater mixes with sewage and results in raw sewage being directly discharged into water bodies. These discharges are called combined sewer overflows and can pose serious environmental and public health risks.
Under the federal Clean Water Act, combined sewer discharges are prohibited without a permit. In December 2000, Congress amended the Act by adding a section that requires each permit issued for a discharge from a municipal combined sewer system to conform to a national combined sewer overflow policy.
The policy is a comprehensive national strategy to ensure that local governments, permitting agencies, entities that establish water quality standards and the public engage in a comprehensive and coordinated planning effort to achieve combined sewer overflow controls that ultimately meet health and environmental standards.
Source: EPA