The Sewer Network
The sewer is one of the most complex systems of our time, combining many functions to protect our water, air and human health. It is a vast underground system of pipes and manholes that collects sewage from homes, businesses, industries and public spaces to be transported to wastewater treatment plants where it is cleaned and returned to the environment.
A sanitary sewer network can be divided into two main categories: combined or separate. The combined sewer system carries sanitary wastewater and stormwater together, and it is typically designed to withstand heavy rainfall events and floods. It also has relief points to prevent flooding in areas where it may not be possible to connect individual buildings directly to The Sewer Network.
Sanitary wastewater is conveyed to treatment facilities through a series of pipes, manholes and pumping stations that can be placed anywhere in the city. The treatment facilities process the sewage to separate out solids and nutrients. The liquid is then sent to a wet well where it is held until it reaches a certain level, at which point it is lifted by a pump and transferred to a storage tank.
During the construction and design phase, the engineer is concerned with several aspects of the sewer. The ground conditions and the flow rate of the sewage need to be taken into account, as this affects how the network is constructed. The size of the pipes, how the pipes are laid and whether gravity flow is used are also important.
The design of the sewer is very important, as it enables the sewer to be designed to last for decades. There are many factors that determine the design, such as the type of ground the sewer passes through, the geology, and whether it is being built to carry a mixture of sewage or just sewage.
There are also a number of other elements in our sewer networks that have been added to reduce the volume of flows that can enter them. These are referred to as stormwater control measures and include a variety of techniques to limit the amount of rain and other runoff that enters the sewer, primarily by using wetlands or other surface features.
These methods can help to reduce the amount of waste that enters a network and can increase the resilience of the network. They can also help to reduce the amount of pollution that enters our waters.
In addition, some sewage treatment plant materials can be hazardous to the environment and humans. Fortunately, regulations are in place to regulate the discharge of chemicals into our sewers.
This helps to ensure that toxic chemicals do not pollute our water supply, preventing them from becoming a public health threat. The MWRA’s Toxic Reduction and Control department monitors for compliance with these requirements and imposes fines on companies that violate the rules.
A common challenge in urban sanitation is that too many households – especially in developing countries – have no connection to the trunk sewerage infrastructure near their homes. This is often due to a lack of information, a surplus of bureaucracy and other related issues that prevent households from connecting to their local sewage network.