Plumbing Full Course - Part 8

                 This is part 8th of the full Plumbing Course. If you want to access the previous parts, you can get it by the end of this post.

Building sewerage & its components

Sewerage systems are composed of several different parts including collection pipes, treatment facilities, and discharge points. A good system should include these components because they are responsible for processing sewage before it flows into your city’s waterway(s). If a sewage system is not maintained properly, this can result in harmful chemicals being released into the environment.

Collection Pipes

                The first step of any wastewater management project is the installation of collection pipes that carry away waste from homes and businesses. These pipes transport sewage from where it is generated to the treatment facility.

Treatment Facilities

                These facilities serve to treat sewage prior to discharging it back into the natural systems. They may use various methods to remove contaminants from the waste stream, such as filtration, chemical precipitation, aeration, and mechanical processes. Treatment facilities may consist of small holding tanks or a large central treatment plant.

Discharge Points

                Once the treated sewage has been discharged back into the natural waterways, it needs to leave the sewers in order to reach the ocean, rivers, lakes, etc. Discharge points typically consist of structures that allow the flow of effluent out of the sewer line. This includes overflow weirs, pressure relief valves, manholes, and other similar devices.

Basic definitions

Building drain

                        A building drain is a pipe that carries sewage from each room through floor drains down into a common area where it flows out of the house. A bathroom has both a vent and a drain; a kitchen usually has only a vent but may have one or two drains. A sink has a single bowl-shaped hole called a trap. When water runs into this hole, it forms a small pool of standing water. This standing water traps bacteria and other organisms that can cause infections. If the drain doesn't work properly, you could get sick!

The bathroom sink drain is placed under your toilet and connects to the waste connection of your toilet. Your shower drain is usually located near the bottom of the tub, although some people prefer to locate their shower drain at the top of the tub. Shower drains are connected to your home's drainage system. A bathtub typically uses a drain pan. Every time you wash, the water goes into a drain pan. In some cases, a bathtub drain can be hard to locate, and you need to call a plumber to install it.

Sewer lines and pipes run vertically through the ground. You can find them outside just about anywhere. Each vertical pipe is generally 1/4 inch inside diameter. They connect together horizontally, forming a network of underground tunnels. Water flows through these drains, carrying away sewage, trash, and anything else that might pollute the water supply.

Building sewer

                        A sewerage system that collects sewage from a building's drains, pipes, or toilets, then disposes of this wastewater through underground channels away from buildings.

Invert level

Invert level is the level of dissolved solids that have been measured at the outlet of the primary sedimentation tank. Invert is not related to the total solid content of sewage and should not be confused with sludge settleability. Sludge settleability refers to the ability of sludges (sediment) to settle from wastewater under the influence of gravity.

            Invert level alludes to the absolute bottom of the lower inside surface of a channel, drain, conduit, and line.

Crown

Crown alludes to the most noteworthy inside level and can be viewed as the "roof" level.

Public Sewer System (PSS)

The Public Sewer System (PSA) refers to the total network of sewers, pump stations, treatment facilities, and other components that are managed by government agencies such as cities and counties. PSSs collects the wastewater generated from residential buildings, commercial buildings, industrial complexes, schools, hospitals, etc. These sewers get into the storm sewers through down-spouts. Storm sewers then carry the sewage towards the water bodies where they are discharged out to sea.

Combined sewer system

A combined sewage system (CSS) is a wastewater treatment technology that treats waste from both sanitary sewers and storm drains. This allows for the collection and treatment of human wastes together with excess rainwater runoff. CSS systems can be either gravity-based or pressurized. They consist of a network of pipes that carry wastewater through at least one pump station where contaminants are removed before discharging into a receiving water body.

Sanitary Sewer system

Sanitary sewers collect and convey the flow of wastewater from residential, commercial, institutional, and industrial sources. Storm drain sewers usually collect surface runoff water from streets and parking lots. These two types of sewers are connected through a series of pumping stations, which treat and filter the solid material and pollutants prior to discharge to a nearby stream, river or ocean.

Wastewater Treatment system

Wastewater from households, industries, and municipalities undergoes a three-step treatment process to remove solids, disinfect bacteria, and purify the treated effluent. First, sediments are screened out using a grit chamber. Next, the water enters a primary settling tank (PST) where the microorganisms settle out. Finally, the clean water rises to the top and exits the PST via a sludge return line.

Manhole

The term ‘manhole’ refers to any underground hole that provides access to sewers, storm drains, water pipes, or other utility systems. Manholes are usually square, circular, octagonal, or hexagonal in shape, but some have a more complex design. They may also vary in size depending on their function.

There are many different types of manhole covers, including grates, hinged lids, removable plates, and self-closing valves. Manholes are commonly used to prevent animals and children from falling into sewers or storm drains.

Manhole Cover

A manhole cover is a lid that covers a manhole that is used for accessing sewer pipes below ground level. Manholes are often found at road junctions, squares, parks, underground railway stations, bus stops, etc. They are usually equipped with handrails to enable people to access them from street level. Some manhole covers have ladders installed so that they can be accessed easily. A typical manhole cover has a hole in the center through which water drains away.

1. A circular steel plate covering a manhole opening in a street or other pavement.

2. A square or rectangular concrete slab cemented over a manhole opening in the ground.

3. Slab used on top of a manhole cover to protect against rainwater entering from above.

4. Manhole cover made of cast iron.

5. Covering for a manhole that is not a slab but has a hole in the middle and is covered with concrete.

6. Concrete slab used on top of a sewer pipe as protection against water drainage.

How to identify manhole / sewer lines / lateral pipes

The term ‘manhole’ refers to any underground hole that provides access to sewers, stormwater drains, or other types of drainage systems. Manholes are usually square-shaped (or rectangular) with a lid over the opening, and a metal grating at the bottom to prevent people from falling into them. There may be a warning sign near the entrance to warn passersby about the hazard. Many public toilets have a sink fitted inside the toilet room, connected to the drain via a pipe. Depending on the type of wastewater treatment system installed, the sewage can either be discharged directly into the street or piped to a tank called a septic tank where organisms break down the wastes before they are discharged into the environment.

A manhole cover has two functions: firstly, to keep out animals and people; secondly, to provide a level surface for traffic. In some places the cover is raised above ground level, allowing pedestrians easy access. Manhole covers come in many shapes and sizes, but they always consist of a flat top plate, a circular base, and flanges around their edges to hold the cover in place. Some manhole covers have a single locking device, while others have two, three, or four locking devices.

There are different types of manhole covers, including cast iron, steel, concrete, and composite. Cast iron is the material used to make most standard manhole covers. Steel covers are used mainly in urban areas since they are relatively lightweight and easier to handle. Concrete covers are commonly found on older installations. Composite covers are becoming increasingly popular, partly because they are lighter than cast iron or steel. A composite cover would typically include both cast iron and plastic components, although this could vary.

When the sewer line is laid below grade, the manhole cover is generally flush with the surrounding pavement, allowing pedestrians and vehicles to easily pass under the cover without stopping. When the sewer line is located beneath an existing building, the cover may protrude slightly above ground level. This allows for a better view of the sewer line and prevents rainwater from entering the sewer line.

Sewer lines can be divided into several categories based on the depth at which they connect to the city's wastewater treatment plant:

Sewer line interceptors - shallow pits dug in front of buildings and along sidewalks, where the wastewater flows through a small conduit to the wastewater treatment plant.

A quick tip if you are looking for manholes or lateral pipes that run through your property. Look for dark marks on walls or structures where these manhole covers have been attached. These are typically at least 1 foot deep and usually, they can be quite large, like 50 feet long. They are often used as a drainage system for stormwater runoff, but also serve as access points to sewers.

If you find any pipes that look suspicious, contact your local utility company. They may offer assistance in locating them and possibly even remove them from the ground. In some states, it's illegal to disturb existing utilities without permission!

Connecting building drain to public sewer

Connections to Building Drain System

The first step is to connect the outside of your house to the building drainage system. You can do this by installing a pipe from the street (or road) to the house's downspouts. This way, rainwater falling on the ground will run off into the storm drains and not back into the street. Once connected to the building's drainage system, the pipes are then connected to the city's sewers.

 Public Sewer Connection

Once the connection between the storm drain system and the buildings' drainage system is finished, you need to connect to the city sewage system. First, you'll have to measure the distance from where the sewage line comes out of the building to where your home connects to the sewage line. Next, determine how many feet that distance is, depending on the size of your house. Then, use a plumber friend to help dig an underground trench about 30 inches deep along the path in between. After digging the trench, put a large piece of plastic over the top of the trench so that no dirt gets into the sewage lines. Finally, install the pipe that runs through the trench and attach it to the city's sewage line.

1. Drain pipe should be installed at least 2 cm above ground level (so that water does not rise into the house).

2. Before connecting the drain pipe to the public sewer, it is necessary to check if the property has been constructed or re-constructed before 1980. If the property has been built after this date, the drainage system may have been altered.

3. A drain test is recommended to determine the quality of your drainage system. This can be done by digging down 5cm below the surface and checking whether any sewage enters the hole.

4. An inspection of the sewage service connection should be carried out. This ensures that the pipes are correctly connected to the sewer, that they do not leak, and that they fit the layout of the sewer.

5. Inspect the sewer service connection for cracks, corrosion, holes, and blockages. Clean the joint thoroughly using a high-pressure hose and soap or detergent. Ensure that the sewer service connection is well sealed.

6. Check the joints between the walls. Make sure they are dry and free from the mortar. Do not use any cleaning products unless specified on the product label.

Connecting Building Sewerage Pipe To Municipal Manhole – Preliminary Works

Preliminary works in sewerage drainage are carried out as per the specifications given by the Municipal Council. The preliminary works include excavation of pits, installation of water mains, laying of pipes for storm drains, etc.

The works are done prior to the construction of the building. The preliminary works take 8-10 days. Once these activities are completed, then the actual construction work can begin.

Procedure for connecting building sewer to manhole

The sewerage from the homes should be connected to the public sewerage system as directed by their respective authority or the municipal bodies.

The building sewerage that is leading to the authority manhole is known as lateral.

1. First of all, find out how much water flow rate is passing through your sewage line. If that amount is not enough, then you need to increase this amount. This can be done either by increasing the capacity of the pump or installing a bigger pipe. As long as this is not possible, you should install a valve at the end of the pipe. You can use a variable speed motor to drive the valve.

2. Now, you must attach the manhole cover to the top of the valve and screw it down tightly using machine screws. Ensure that the threads of the valve are well connected to the manhole cover. Also, make sure that the valve is properly aligned over the manhole.

3. Then check if the valve works fine and does not leak any water. Once you are satisfied with its working condition, you have completed step no. 1.

4. Next, connect the sewage pipe from the building sewers to the valve. Make sure that the connection between the pipe and the valve is tight and completely sealed.

5. Finally, turn the handle of the valve clockwise till the valve opens fully.

Connecting sewer pipe to manhole

The first step in connecting a building sewer pipe to a manhole is to have an engineer review the existing piping and make sure that it meets city requirements. This is done through construction drawings. The engineer then makes a recommendation of what type of connections are needed so they can be ordered from the manufacturer. These connections are then laid out according to the standards set forth by your local municipality.

Attaching manhole cover

Once the pipes are connected properly, a manhole cover is attached. The cover should be secured using bolts to prevent water intrusion into the system. If a metal cover is used, it needs to be plated with a corrosion inhibitor to help reduce rust. Some covers come pre-installed with a locking mechanism.

Cleaning and painting sewer lines

Sewer cleanings are performed regularly to ensure the best performance of the system. The line is cleaned using chemicals and is then rinsed. Once completed, the walls of the line are primed and painted.

Access Previous parts of this course, if you have missed them, by clicking Below...

Part 1 -- Click Here!!

Part 2 -- Click Here!!

Part 3 -- Click Here!!

Part 4 -- Click Here!!

Part 5 -- Click Here!!

Part 6 -- Click Here!!

Part 7 -- Click Here!!