What Does Combined Sewer System Mean?
Combined sewer system as the name suggests is a single pipeline system carrying waste water from homes, offices, and industries, and storm water from surface runoff, together to the treatment plant. This system was introduced in the mid-19th century and was a great improvement over the existing sanitary system. This system is still operational in some older areas but is becoming a problem due to overpopulation with sanitary loads on the combined pipeline increasing beyond capacity during times of heavy rainfall.
Trenchlesspedia Explains Combined Sewer System
The combined sewer system is designed to discharge all the waste to the sewage treatment plant where it is treated and then released into a water body. However; during times of overflow as in the case of heavy rainfall, the sewer system exceeds capacity prompting discharge of waste water including human waste, and industrial effluents to be directly dumped into the water body. This is very harmful for vegetative and aquatic life existing in such areas. This problem has prompted authorities to stop the installation of combined sewer systems in new constructions. It is no longer feasible in today's society owing to densely populated cities with high sanitary load, and commercial needs, and industrial effluents also requiring proper treatment and disposal.