Pipes to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility. Collector sewers are a part of multi-tiered wastewater collection systems in a given area that are used to bring waste from smaller streams into wastewater treatment plants. The tunnels and pipes throughout sewage systems are usually equipped or kept using construction methods without trenches. Collector sewers can be varied in different countries, municipalities, or regions, and sometimes be referred to as the main sewer.