CE 39 Midterm PDF

SEWAGE DISPOSAL treatment does it become - process of removing and destroying acceptable by standards that it is or converting the noxious equal it to natural river water substanc...

SEWAGE DISPOSAL treatment does it become - process of removing and destroying acceptable by standards that it is or converting the noxious equal it to natural river water substances of sewage or Treatment Plants wastewater especially by - Treatment plants work to separate ammonification and nitrification the waste- water into supernatant through bacterial action. liquid and sludge. Supernatant SEWAGE DISPOSAL METHODS liquid, after further treatment, is then 1. Through sewer systems - a standard discharged to rivers, waterways in built up areas (cities and industrial oceans, and aquifers while sludge is areas) dried and deposited into ponds and 2. On-site sewerage treatment - usually settling beds. Sludged can also be found in residential, rural areas. used as a fertilizer. 3. Chemical toilets - used by airplanes, long distance vehicles (trains, On-site sewage treatment caravans, buses). - These are multi-stage systems that SEWAGE TREATMENTS collect, treat and disperse water - consists of primary (physical) and generated by a home or secondary (chemical and biological) business.The wastewater is treated treatment and discharged to the soils rather - two types of systems: than collected and transported to a on-site sewage treatment wastewater treatment plant. off-site sewage treatment OFF-SITE SEWAGE TREATMENT SYSTEMS Usually for urban areas, houses and buildings are arranged a long a street each have a household sewer pipeline connected to a communal sewer which leads to a wastewater treatment location then, via a main fall out, to rivers and other irrigation areas. STEPS OF ON-SITE OFF-SITE TREATMENT METHODS WASTEWATER TREATMENT - can be restricted to primary level treatment, which includes: Identifying the source Discharge sources degreasing, grit removal, sludge for residential areas include plumbing thickening and digestion. fixtures, toilets, laundry, and dishwater. - After treatment, the water is usually Commercial wastewater comes from dumped into the ocean or a restaurants, manufacturing plants, and perennial river outfall. businesses. - This “treated” water is considered to still be raw sewage, only when it Collection and Storage of Wastewater passes through a secondary Solid rigid pipe collects wastewater from plumbing fixtures and appliances. The pipe 5. Secondary Clarifier - treated wastewater is laid at a downward slope which leads to is pumped the pre-treatment plant. into a secondary clarifier to allow any remaining organic sediment to settle out of treated water flow. STEPS OF ON-SITE 6. Chlorination - Chlorine is added to kill any WASTEWATER TREATMENT remaining bacteria in the contact chamber. Pre-treatment of Wastewater - involves 7. Water Analysis and Testing - proper pH removing contaminants from the wastewater level, to prepare it for the final treatment. Some of ammonia, nitrates, phosphates, dissolved the pre-treatment components include trash oxygen, and residual chlorine levels are tanks, septic tanks and processing tanks. tested to conform to the plant's NPDES permit are critical to the plant's Final Treatment and Dispersal of performance. Wastewater - final removal of contaminants takes place and the water can be safely 8. Effluent Disposal - After meeting all dispersed into the environment. The permit specifications, clean water is treated wastewater can be distributed into reintroduced into the environment. the soil through different methods. One of the most widely used systems is the gravity flow system as it is the least expensive and requires less maintenance. STAGES OF WASTEWATER TREATMENT There are 8 stages of an on-site treatment system: 1.Bar Screening - removal of large objects that can damage the equipment 2.Screening - removal of grit through a grit chamber 3.Primary Clarifier - separation of solid organic matter from wastewater 4.Aeration - air is pumped in a tank to encourage NO3 development (from NH3); also provides oxygen to encourage bacterial growth THE SEPTIC TANK employed. Mound systems use a sand-filled SEPTIC TANK SYSTEM mound atop natural soil over a drain field. As it passes through this sand layer and into Private septic tank systems treat the soil, wastewater is cleaned. wastewater underground. Rural regions without municipal sewage systems use SAND FILTER septic tanks. Septic tanks break down Sand filter systems, like mound systems, biodegradable waste from a home's or employ a layer of sand and a pump to business's sewage system. Septic systems cleanse and disperse wastewater where soil handlen bathroom, kitchen, and laundry is limited. One of the most typical septic wastewater using nature and technology. systems is a sand filter. Sand is located in Septic tanks and soil absorption fields make the space that may be found between the up most septic systems. Wastewater is pump tank and the drain field. Before drained from the septic tank into the entering the drain field, wastewater must be drainfield, chambers, or other slow-release treated with sand. When conventional devices in soil-based septic systems. systems lack soil, which is common in treating wastewater, sand may be used as a 2 TYPES OF SEPTIC TANK SYSTEM substitute. 1) Conventional System PEAT MOSS 2) Alternative System Between the septic system's pump tank and a. Aerobic Treatment Unit (ATU) drainfield, peat moss is used in systems that b. Mound rely on this kind of waste treatment. Prior to c. Sand Filter Peat entering the drainfield, the wastewater is d. Peat Moss mostly treated by the peat. Areas with a limited depth of soil or a high groundwater AEROBIC TREATMENT UNIT (ATU) table often benefit from peat moss systems. ATUs break down solid waste using oxygen, HOW A CONVENTIONAL SEPTIC producing “cleaner” wastewater than SYSTEM WORKS conventional septic systems. Aerobic bacteria in the septic tank need oxygen to Septic tanks are underground, watertight grow and thrive. Aerobic bacteria containers often built of concrete, fiberglass, decompose household and business waste. or polyethylene. The drain field is an open, Aerobic Treatment Units are frequent in covered trench dug into relatively dry ecologically sensitive places where ground. In order to further cleanse the wastewater needs further treatment before wastewater before releasing it, the pipes being released into the drain field. are perforated so that the water may escape into the ground. Water that has been used MOUND for other purposes is absorbed, purified, and When the drain field is elevated or there is distributed throughout the soil before it little soil for treatment, mound systems are enters the groundwater system. erected. When soil depth is inadequate for a conventional system, the mound design is  septic system maintenance may cause concrete septic tanks to break sooner. Cracks in the concrete of the septic tank allow waste to leak out. Similarly, groundwater might find its way into the tank. In any case, the seepage might be a source of complications. Septic systems may back AEROBIC SEPTIC SYSTEM up if there is a blockage in the tank from too much waste. Concrete septic tanks need to When compared to conventional septic be inspected on a regular basis and systems, aerobic ones are both more maintained as needed. difficult to set up and maintain financially. Trash chamber, Aeration and Clarifier STEEL SEPTIC TANK chamber, and Pump chamber are all handled in separate sections. Wastes are They are the weakest and least popular. It decomposed more quickly and efficiently by endures 20-25 years. This is because steel anaerobic bacteria than by anaerobic septic tanks corrode before 25 years. The bacteria in traditional systems. Before the steel septic tank lid might corrode and wastewater reaches the last step of collapse under the weight of a human. The treatment, it is deemed "environmentally examination and maintenance of steel safe" enough to be spread on topsoil septic tanks must be performed manually on vegetation. a regular and intermittent basis. PLASTIC OR FIBERGLASS SEPTIC TANK Unlike steel and concrete, plastic or fiberglass septic tanks are water-resistant and resistant to rust, corrosion, and cracking. However, fiberglass or plastic septic tanks have weaknesses. Dislodged tank plugs might cause low effluent. Even when effluent levels are normal, septic tank 3 KINDS OF SEPTIC TANK YOU SHOULD blockages must be inspected. Check septic KNOW tank clogs during pumping and maintenance. Pumping may loosen clogs. 1. Concrete Septic Tank Plastic or fiberglass septic tanks are more resistant to natural elements and processes 2. Steel Septic Tank inside the tank, but their lightweight construction makes them prone to structural 3. Plastic or Fiberglass Septic Tank damage. CONCRETE SEPTIC TANK CONSTRUCTION OF THE SEPTIC TANK It can crack, rust, or even separate. SEPTIC TANK DESIGN Low-quality concrete mix and inadequate Users and sludge removal intervals made of M15 concrete and slope 1:10 determine septic tank capacity. Every two toward the sludge exit. years, remove sludge. 95-150 liters of human waste, including kitchen garbage, is Walls - In order to have appropriate produced daily. Septic tanks have 23cm strength and protection from water, the walls brick or RCC walls and 15cm cement need to be thick enough. Brick walls must concrete 1:2:4 foundation floors. The walls be at least 200mm thick and plastered with and floor are plastered with 12mm cement a cement mortar ratio of 1:3. Stone masonry mortar 1:3 mix. All septic tank corners are walls must be at least 370mm thick. rounded. Impermo, Cem-seal, Accoproof, and others are put into cement mortar at 2% Slab - Septic tanks have 75-100mm RCC by weight. It prevents concrete leakage. The slabs on top, depending on size. For septic tank floor slopes 1:10-1:20 toward the inspection and desludging, 500mm inlet side floor. manholes are provided. When the opening is rectangular, the size stays at SEPTIC TANK DESIGN 600x450mm. Partition or Baffle Wall - A permanent partition may divide a septic tank above 2000 liters into two chambers. The partitioning must be set such that the first chamber's capacity is double that of the second room. At 300mm below TWL, the partition shall have rectangular or circular apertures with a minimum diameter of 100mm and a maximum diameter of 150mm. Cover and access holes - Each septic tank compartment must have a 445x610mm rectangular access aperture or a 500mm circuit opening. HOW TO DESIGN A SEPTIC TANK Pipe Ventilation - Septic tanks must have Example: A small house of 20 people 50mm ventilation pipes. The pipe must be having a secure water supply from the enclosed in a protective mesh cage that municipal headwork at a rate of 120 keeps mosquitoes out. liters/person/day. SEPTIC TANK CONSTRUCTION The quantity of water supplied = Per Capita rate x Number of persons Floor - The tank's base has to be The quantity of water supplied = 120 watertight and sturdy enough to maintain x 20 the tank's weight, walls, and interior during The quantity of water supplied = earthquakes. To aid desludging, it should be 2400 Considering that 80% of water supplied becomes sewage The quantity of sewage produced = 2400 x 0.8 = 1920 per day Considering the detention time of 24 hours The quantity generated during the detention time/ tank capacity = 1920 HOW MANY GALLONS DOES A x 24/24 = 1920 liters STANDARD SEPTIC TANK HAVE? Considering the deposited sludge rate as 30 The amount of people that reside in a liters/capita/year and the cleaning period of residence on a typical day and their water 1 year = 30 x 20 x 1 = 600 liters usage will determine each septic tank's HOW TO DESIGN A SEPTIC TANK capacity or hold. Since a home's water capacity might range from the smaller 750 Total Required capacity of the tank = gallons to the larger 1250 gallons, the size Capacity for sewage + Capacity for sludge of the home will also affect the septic tank's Total Required capacity of the tank = 1920 + holding capacity. 600 = 2520 or 2.52 cubic meter Considering the tank's depth of 1.3 meter Tank's surface area = 2.53/1.3 = 1.94 m^2 Considering length to width is 1:3 Length x Width = Area 3B x B = 1.94 B^2 = 1.94/3 B = sqrt 1.94/3 B = 0.8 Kinsa ni iguana? Width of the Tank = 0.804 Length of the Tank = 3 x 0.804 = 2.412 Area of cross-section required = 2.412 x 0.804 = 1.939 or 1.94 0.3m assuming as freeboard The dimension WASTE PIPES of the septic tank will be 2.412m x 0.804m x - Is smaller in size than the soil pipe (1.53+0.3) m overall depth. Thus, the size of - Smaller because of the kind of waste the tank is = 2.412m x 0.804m x 1.6m ir receives from the various plumbing fixtures - Suspended materials found in the water waste: - Grease - Lint - Matches - hair garbage  - “The waste pipe GENERAL CONDITIONS FOR A GOOD diameter shall be WASTE PIPE adequate enough to 1. By making the right choice of serve the installation materials of fixtures in a - The character of the waste to general way, but the be drained and the service to best way is to fit the which it is intended for, diameters of dictates the kind of materials commercial pipe into to be used. the fixture pattern in 2. By conservative use of fittings the efficient manner” - The smooth flow waste - This is to accommodate the inside the pipe is a primary velocity of flow, making them consideration in all types of as nearly scouring as plumbing installation. necessary to prevent the - Pipelines were attributed to silting of the pipe. the unwarranted use of accessories and too many RECOMMENDED SIZE OF WASTE PIPE fittings or because of using 1. Sink Waste the wrong type of fittings in a - The minimum side of the given location. waste pipe is 38mm or 1 1⁄2 3. ? nut because of the materials 4. Right Slope or Grade of the suspended in it, the practice Pipelines is to use 50mm or 2” pipe. - The ideal position of The National Plumbing Code horizontal waste pipe, were provides that: those installed at 2% slope. - “The waste pipe must Meaning, the pipe was be short, direct, free installed with an inclined rate from offsets and of 2 centimeters per meter provided with ample length. cleanouts accessible 5. Manner of Joining Pipes for repair.” - Injudicious connection of 2. Slope Sink fittings should not be - Is tapped either on the floor permitted in any plumbing or walls. Traps on the floor installation. shall be 75 or 100mm for - Each kind of pipe has its traps installed on walls with manner of joining cleanout plug. recommended and specified 3. Scullery Sink - 50mm by the manufacturers. 4. Panty Sink - 38mm 6. Determining the Size of Waste Pipe 5. Factory Wash Up Sink - 50mm - The National Plumbing Code 6. Bathtub - 38mm min to 50mm on the size of waste pipe 7. Lavatories - 50mm provides that: 8. Shower Bath - 50mm  9. Urinal - 50mm - Terminates into lake, river, 10. Laundry Tub - 38mm to 50mm dry run or natural basin. 11. Drinking Fountain - 32mm 3. Industrial Drain 12. Lavatory Waste - 50mm - Is a house drain that receives 13. Hospital Fixtures - 50mm discharges from industrial equipment that contain some HOUSE DRAIN objectionable acid wastes. - Is that portion of the plumbing - Industrial drain that contains system that receives discharges of acid waste terminates into a all soil and waste stacks within the separate drainage basin. building, and conveys the same to the House Sewer. A. DETERMINING THE SIZE OF - Sometimes referred to as the HOUSE DRAIN Collection line of a Plumbing System The Unit System is the most - Can be installed underground, or practical method to use in determining the maybe suspended below the floor or size of a house drain. It has been inside the ceiling. formulated from tests conducted by the - In large buildings, it is usually Uniform Plumbing Code Committee, a body suspended from the basement consisting of representatives of ceiling to avail of the gravity flow management, labor and government waste to the Main Sewer. standard agencies. Four Types of House Drain 1. Combined Drain Sanitary Drain - Is a type of drain that - If the purpose is for sanitary waste, receives discharge of the Fixture Unit load discharges will sanitary waste as well as be the basis of computation. storm water. Storm Drain - The oldest form of house - If the purpose is for storm drain, the drain when public sewers are roof area that accumulates the major of the combination design rainfall water will be the basis in - Already phase out and no determining the size of the pipe. longer permitted - Receives the discharge of On House Drain, the Plumbing Code sanitary domestic waste only. Provides that: - The waste is conveyed to a 1. No water closet shall discharge into public sewer or septic tank a drain less than 75 mm or 3 inches by the house sewer. pipe diameter. - Stormwater is not allowed for 2. No more than 2 water closets shall this drain discharge into any 75 mm horizontal 2. Storm Drain soil branch, house drain or house - Conveys all storm clear sewer. water or surface water waste except sanitary wastes. B. GRADE SLOPE OF HOUSE DRAIN - The Main Sewer line is The house drain being a horizontal financed and maintained by pipeline must produce the necessary the government. Those velocity and discharge capacity at certain houses along the street with inclination, to attain scouring action. House main sewer line are required function drain without abnormal or must to connect mian sewers to pressure in the plumbing system. the public sewer line. Exceptions: B. HOUSE CONNECTION OF HOUSE 1. When the depth of the sewer line in SEWER relation with the depth of the - the house sewer is basement floor is low. connected to the main sewer 2. Long sewer line would require lower by boring a small hole pitch but should not be less than 1%. through the concrete pipe, 3. In case the sewer line slope is very using a sharpened steel slight, installation of the pipe should chisel or electric drill. The be guided by a leveling instrument hole is gradually enlarged to for accuracy to prevent sags or receive the sleeve. Extra trapped piping. care should be exercised not 4. A pitch or slope more than 2% to break the inside wall of the percent, will increase the velocity main sewer. and discharge capacity of the pipe, - The House Sewer pipe is the effect could connected to the Main Sewer - A danger that it might entering at 45 degrees angle decrease the depth of the or directly from the top. water that is necessary to GENERAL CONDITIONS OF INSTALLING create a scouring action. SEWER PIPE - This might cause a minus 1. Secure permits from the sewerage pressure if the drain is authority. overloaded to a flow capacity. 2. Verify the depth of the house drain A. HOUSE SEWER outlet. - that portion of the horizontal 3. Determine the depth of the drainage system, which connection with the main sewer in starts from the outer face of the street and the grade of the the building and terminates house sewer. at the main sewer in the 4. The depth is found by measuring the street or septic tank. length of the longest branch of the - Other code defined House house drain multiplied by the Sewer as, that portion of the pre-planned pitch per meter. horizontal drainage system, 5. Add the required 30 cm ground which starts 90 centimeters coverings from the top of concrete from the outer face of the floor or 40 cm of ground covering building. House sewer is without concrete floor. sometimes called the 6. 6. Verify the depth of the connection Building Sewer. to be made with the main sewer.  Remove the manhole cover on both carried to some natural ends. Measure the depth using a drainage terminal like canals, meter tape or stick. rivers, lakes, etc. 7. The grade of the house sewer could - Drainage gives excess water be found through the difference a place to go to prevent it between the House Sewer and the from building up and causing depth of the Main Sewer. A leveling floods. A series of instrument will give a satisfactory above-ground drains, result. Additional grade can be made underground pipes, and with the use of 1/8 bend considered open-air ditches combine to as the most practical method of safely transport runoff to an establishing grade. area better suited to hold it, like streams, creeks, rivers, C. SIZE OF A HOUSE SEWER bayous, and oceans. - The size of house sewer for - Similar to sewers, residential connection to the main or stormwater drainage consists septic tank has been established by of a system of pipes and sanitary authorities, based on their channels that transports records of installation tests, and runoff away from residential mathematical conclusions. areas. Impervious surfaces, - Old practice: like roads and sidewalks, - Use 150 mm or 6 in. cause excess water to diameter cement/vitrified clay accumulate. pipe for house sewer FOUR TYPES OF STORM DRAIN - For plastic pipe or its interior surface 1. Reinforced Concrete Pipe texture equivalent is used, reduce - Reinforced concrete pipes diameter to 100 mm (subject to the are one of the strongest and standard rules, promulgated by the most heavy duty options for National Plumbing Code) storm sewer piping. They are - In selecting sewer pipe for hotels, heavy and quite challenging apartment houses, commercial and to install. Large equipment industrial buildings, the total must be used to move, lift, discharges in terms of fixture unit, and lay them. They have overlapping of discharges and the shorter lay lengths than other simultaneous use of the fixtures are types of pipe, typically 8 feet. considered. 2. High Density Polypropylene Smooth Interior A. STORM DRAIN - It's a great choice for sewer - unit of the plumbing system drainage system projects due that conveys rain or storm to the ease of installation and water to a suitable terminal. the longer lay length. The - Normally discharged into a typical lay length for this pipe street gutter conveyed by a is 20 feet. public drain system and 3. PVC - Polyvinyl Chloride  - PVC pipes are the 3rd - Slotted Drain is a material to consider. It is a continuous opening good storm sewer drainage inlet that efficiently material because it is less removes surface costly to purchase, but water on streets and typically costs more than highways. HDPP or HDPE (HDPE is - Combination Inlet high-density polyethylene - Usually a combination while PP is polypropylene.). of a curb opening It has a typical lay length of inlet with a grate inlet, performance opine pite once although other tinal backil is completel combinations are 4. High-Density Polyethylene Smooth possible. Interior - Culverts - This material is the last of the - Culverts are massive 4 listed options. It is pipes that carry manufactured using stormwater application-specific underground to a high-density polyethylene local pond, treatment and offers high abrasion and plant, or another corrosion resistance. Just destination. They are like PVC, it's lightweight handy for allowing the which makes it cost effective water to flow under to install. It also requires a roads, railroads, and minimum coverage depth to other surface-level use. constructions. A PARTS OF A DRAINAGE SYSTEM culvert might have Inlets one or two inlets - Storm drain inlets are the openings connected to each that allow stormwater to flow into a section. storm drainage system. There are - Manholes many types of inlets, including: - is an opening to a - Curb Opening Inlet confined space such - A curb inlet is used to as shaft, utility vault, assist in the storm or large vessel. water drainage of the - are often used as an paved surface area access point for an - Grate Inlet underground public - A grate covering to a utility, allowing drain at the low point inspection, of a road, swale, or maintenance and another drainage site. system upgrades. - Slotted Drain Inlet - Trunk Line  - The trunk line, or elevation than the basement "main" is the main floor of the building. pipeline that carries - purpose is to avail of the the stormwater away. gravity flow of water. The The storm drain will pipe is well fitted and lead water into this suspended inside the ceiling system, which flows by suitable hangers spaced at a steady rate and at closer intervals. takes in a steady C. SIZE OF A STORM DRAIN - amount to preventa - The size of the storm drain the surcharge. following considerations: CLASSIFICATION OF A STORM DRAIN - Cloging of rainfall over a 1. The Inside Storm Drain given period, whether i is - The Inside Storm Drain is constant or exceedingly sometimes located under the heavy shower of short basement floor or within the - Considering the varying roof walls of the building. This areas, the slope, and the type of storm drain is distance traveled before it commonly found in buildings reaches the conductors constructed along congested one roof. business district, or buildings - Water drains faster on high that occupy the entire pitch roofs. Hence require a frontage of the lot. The drain large drainage pipe than that pipe is laid under the floor or of a flat roof. walls of the structure. - The height of the building, - For large buildings,storm contribute largely to the drains are laid in two or more velocity of water falling inside lines to colvey not in the a vertical pipe conductor. The water coming from the root, fall accolerate the flow of but also those waters water entering into the storm accumulated from the inside drain. court or open areas towards - The use of improper fittings the street gutter or public and short offsets will affect storm drain. the flow of water must be 2. Outside Storm Drain avoided. - is installed outside the - The conservative estimate of foundation wall of the maximum rainfall in the building. Philippines is about 20 mm in - possible on locations where a 5 minutes interval. the lot is not totally occupied by the building. D. GRADE CHANGE OF DIRECTION 3. Overhead Storm Drain - The storm drain is installed providing - is adopted when the street a slope of not more than 2% per drainage is higher in meter run. A combination of Y and ⅛  bend or a long radius fitting is appropriate for any change in VENTING METHODS direction. Conventional Venting (Individual Venting) Common Venting ROOF LEADER Wet Venting - is popularly known as water Circuit Venting conductor or downspout either Combination Waste and Vent concealed or exposed type. Island Fixture Venting (aka Island Sink - connects the roof terminal to the Vent) storm drain. Waste Stack Venting Single-Stack Venting PLUMBING VENTILATION A plumbing vent, or a vent stack, regulates CONVENTIONAL VENTING the air pressure within your home’s - is when each fixture has its own plumbing system. They’re comparable to plumbing ventilation. This plumbing drain pipes, which remove waste and water ventilation is called Individual Vent. from your home; plumbing vents remove the Individual vent is a single pipe that gas and odor from your home. This also vents a plumbing fixtures trap. allows fresh air into the system, which COMMON VENTILATION improves pipe drainage and water flow. - is an individual vent that connects at the intersection of two trap arms. The vent stack is a vertical drain line that - This is a convenient way to vent two goes through your home’s roof to reach the plumbing fixtures with one vent pipe. outside. No running water goes through the Typically the fixtures are set plumbing vent. It connects with your main "side-by-side" or "back-to-back." roof vent, allowing gases to vent and - For example, a double bath lavatory maintain the proper pressure within your or back-to-back bath lavatories home’s plumbing system. WET VENTILATION - is a pipe that serves as both a drain WHY IS IT NECESSARY? and a vent. It is a great way to plumb A plumbing system is created to move a bathroom with one vent. It's also a waste and water efficiently out of a home. popular choice among pros because The drainage and vent systems work it's fast, efficient and requires less together to make this happen. fittings than a conventional plumbed Drainage pipes carry the waste to the city bathroom. Both major plumbing sewer or septic lines. The vent codes allow wet venting. However, pipes ensure fresh air gets into the drainage each code has special sizing pipes so that water can move requirements because the pipe acts from the toilet, sink, or shower when in use. as both a drain and a vent. When these systems are out of balance, CIRCUIT VENTILATION they work against each other, - an efficient method of venting a causing various plumbing issues in your battery of plumbing fixtures with one home. Over time, these issues can single vent. The circuit vent be costly to repair if ignored. connects between the two most  upstream fixtures. As few as 2 Please note: The UPC does not permit fixtures or a maximum of 8 fixtures waste stack venting. may be served by the circuit vent. The general idea behind waste stack Plumbing codes also require the venting is fixtures (other than toilets and installation of a relief vent when the urinals) use the oversized waste stack as following conditions occur: the vent. - 1. Four or more water closets This system is limited to "waste" only. Toilets connect to the circuit vented and urinals are not permitted to horizontal branch discharge into the waste stack. - 2. The circuit vented branch Additionally, a special table in the code is drain connects to a drainage used to oversize the stack. stack receiving discharge from Vertical and horizontal offsets are not fixtures on an above floor. allowed and a full size stack vent is also required. COMBINATION WASTE AND VENT (CWV) This system has also been called multistory A special venting method using the stack-venting, Philadelphia single-stack and horizontal wet venting of one or more sinks, multi-story vertical wet vent. But again, the floor drains, lavatories or drinking fountains IPC refers to this venting method as a by means of a common waste and vent Waste Stack Vent. pipe. This pipe is oversized to allow the free movement of air (above the drain's flow SINGLE-STACK VENTING line). Due to the oversized pipe, a CW This venting method is similar to waste system loses its self-scouring (self-deaning) stack venting combined with the characteristics. To prevent drain blockages, combination waste and vent (CW) method. plumbing codes restrict what fixtures can This system relies on an oversized drainage use this system, only fixtures producing stack and oversized branch connections to "waste" are permitted. Toilets, urinals, and serve as both the drain and the vent.mThis clinical sinks are not allowed. Floor drains, venting method was added to the IPC in sinks, lavatories and drinking fountains are 2012, however, it hasnt gained mass allowed. popularity as there are many special rules and limitations. ISLAND FIXTURE VENTING When an individual vent cannot be installed because a sink isn't next to a wall, an island TRAP SEAL LOSS sink vent is a possible solution. This vent WAYS FOR TRAP-SEAL LOSS differs from a conventional individual vent Trap seals can be lost as a result of poor because it offsets horizontally below the practice and by not following the regulations sink's flood level rim. There are 3 main ways in which trap seal WASTE STACK VENTING may be lost due to poor practice A waste stack vent is a special venting method covered under section 913 of the 1. Self-siphonage IPC. 2. Induced-siphonage 3. Compression  out the water. Detergent foam increases the SELF-SIPHONAGE risk of compression. This is most common in wash basins. Their shape allows the water to escape quickly. WHY TRAPS LOSE THEIR SEAL As the water escapes a plug of water is The main reasons for traps losing their seal formed creating a partial vacuum (negative are bad pipework design and poor pressure) in the water pipe between the installation. water plug and the basin. This is enough to siphon the water out of the trap. Ensuring Momentum - Trap seals can also be that the water pipe is within lengths allowed, removed by the force of water. This can to the correct fall, or that it is ventilated happen if you pour a bucket of water down should help prevent self-siphonage. a basin or a toilet. Resealing traps (anti-vac) should also prevent this. Wavering - Wind pressure above the top of the soil and vent pipe, particularly exposed INDUCED-SIPHONAGE areas causes the water in the trap to waver This is caused by a discharge of water from and wash over the weir of the trap. This another appliance this is connected to the does not happen often, and can be avoided same waste pipe as other appliances. As by fitting a 90 degree elbow or cowl at the the water plug flows past the second top of the vent pipe. appliance connection, negative pressure is created between the pipe and the appliance Evaporation - The most common form of that siphons the water out of the pipe. This natural seal loss occurs in a very warm, dry arrangement is not acceptable on primary weather when an appliance has not been ventilated stack. used. The water simply evaporates. It is unlikely to occur in traps with a 75mm seal. COMPRESSION As the water is discharged into the main RETARDATION OF FLOW stack (usually a WC at the first floor level) it Retarded water flow inside the pipe is the compresses at the base of the stack result of improper atmospheric conditions causing back pressure. This can be enough because of insufficient ventilation or to force the water out of the trap, causing incorrect installation of fittings. loss of seal. The use of large radius bends It can be corrected by providing ventilation and minimum of 450mm length between the pipes to equalize or balance the invert drain and lowest pipe are defined in atmospheric pressure inside the plumbing the regulations in order to prevent this. installation. Example: Pouring condensed Compression or back pressue occurs in milk from a tin can high rise buildings. When water is discharged down to the main discharge stack, air compressed at the base of the stack. A waste pipe connected to the stack in the pressure zone may have the seal of the trap lost by the compressed air forcing VENTILATING THE discharge pipe, is typically a vertical pipe DRAINAGE SYSTEM that Ways and forms of ventilation depend removes sewage and greywater from a upon the location of the fixtures or how they building. It is often attached to the exterior are combined or grouped. of a building (although it may be fitted Ventilating all fixture traps individually is internally) and connects the subterranean costly. Economically, group venting was drainage system to a point just above the permitted provide that every trap is level of the roof gutter. ventilated using the proper size of vent pipe as recommended by the National Plumbing Soil vent pipes allow the removal of waste code from toilets, showers, baths and sinks, while also allowing odours to be released above TYPES OF VENTILATION IN THE the building, via a stack vent, at a level that PLUMBING SYSTEM will not cause a nuisance. The pipe's vents A. Main soil and waste vent also allow air into the internal drainage B. Main vent system so as to facilitate the process of C. Individual vent aerobic sewage digestion, preventing a D. Unit vent siphoning affect from occurring, and E. Circuit or loop vent allowing free flow by gravity. F. Relief Vent G. Looped vent SVPs must maintain sufficient downward H. Wet vent slope along their length to keep liquids and entrained solids flowing freely towards the A. MAIN SOIL AND WASTE VENT drain. If a downward slope is not possible, a Portion of the soil stack above the highest collection pit with a 'sewage ejector' pump installed fixture branch extending through can be installed. the roof. It serves as the terminal for the main vents and other vent of the system. Traditionally, soil vent pipes were made from cast iron; however, today they are GENERAL CONDITIONS IN INSTALLING most commonly made from uPVC. THE MAIN SOIL AND WASTE VENTILATION DRAIN WASTE VENT 1. That, it must be installed as direct as In modern plumbing, a drain-waste-vent (or possible. DWV) is a system that allows air to enter 2. Short radius fittings should be avoided, the plumbing system to maintain proper air because it reduces the flow of the air. pressure to enable the removal of sewage 3. As much as possible, long horizontal line and greywater from a dwelling. Drain refers must be avoided to water produced at fixtures such as sinks, 4. Generally, it should have the same and showers; waste refers to water from diameter as the soil or waste pipe. toilets. As the water runs down, proper venting is required to allow water to flow SOIL VENT PIPE freely, and avoid a vacuum from being A soil vent pipe (SVP), also known as a soil created. As the water runs down air must be stack pipe, drain-waste-vent or ventilated allowed into the waste pipe either through a be installed. In this type of vent, water and roof vent (external), or an internal vent. waste discharged. B. THE MAIN VENT Individual Vent- An individual vent, also Is little more than a pipe that runs from a known as a back vent, is a vent that plumbing fixture up through the roof of the connects the main vent with the individual home. trap underneath or behind a fixture. When In very simple terms, this pipe allows air you install two or more fixtures on an pressure to escape from the plumbing individual vent basis, ensure the leg system. connecting individual vents to the main vent Note: Without a vent to allow pressure is large enough to carry the total load. to escape from the plumbing system, harmful sewer gases can build up. Looped Vent- A loop vent is a venting solution for a sink fixture P-trap that requires There are important criteria to remember the vent pipe to run under the floor, such as when sizing a conventional venting system a kitchen island sink. It rises from the trap composed of individual fixture vents, vent and forms a loop inside the sink cabinet stacks, and stack vents. before dropping under the floor and running The sizing criteria for stack vents and horizontally to the vent stack. vent stacks are based on three variables: 1. The developed length of the vent. Wet Vent- Wet venting is a plumbing term 2. The size of the stack served by the vent. and is a method of protecting the trap on a 3. The total drainage fixture unit (FU) drain pipe on multiple plumbing fixtures. It is connected to the stack. a useful method of venting and can save pipe and fittings, time and money. Individual Vent~ A pipe installed to vent a fixture trap and that connects with the vent Practical Examples: system above the fixture served or 1) Toilet and Sink: terminates in the open air. The toilet is vented through the sink drain. Stack Vent~ The extension of a soil or The toilet drain should be 3", the sink drain waste stack above the highest horizontal is 1.5" the shared sink drain/toilet vent area drain connected to the stack. should be 2", and the vent going up should be 1.5". Vent Stack~ A vertical vent pipe installed primarily for the purpose of providing 2.) Toilet, sink and tub (or shower): circulation of air to and from any part of the Like the previous picture the toilet and sink drainage system. are wet vented together. This time the wet vent connects to the vertical leg of the toilet Circuit Vent- A circuit vent extends from the drain which is also good. Also this time we main vent to a position on the horizontal have a tub connected to the wet vent. branch between the last two fixture connections. If more than eight fixtures are to be vented, an additional circuit vent is to Relief Vent- A branch from the vent stack, connected to a horizontal branch between the first fixture branch and the soil or waste stack, whose primary function is to provide for circulation of air between the vent stack and the soil or waste stack. UNIT VENTING Vent allows gases in the sewage drainage system to discharge to the outside. It also allows sufficient air to enter, reducing the air turbulence in the system. Without a vent, once the water is discharged from the fixture, the moving waste tends to siphon the water from the other fixture traps as it goes through the pipes. This means that the vent piping must serve the various fixtures, as well as the rest of the sewage drainage system. Pang memorize hehe along a street, each with a household sewer pipeline connected to a communal sewer leading to a Sewage Disposal wastewater treatment location, then via a main fallout, to rivers and other and Wastewater irrigation areas Can be restricted to primary level Treatment treatment, which includes: degreasing, grit removal, sludge thickening and digestion SEWAGE DISPOSAL After treatment, the water is usually dumped into the ocean or a process of removing and destroying perennial river outfall, and is or converting the noxious substance considered to still be raw sewage of sewage or wastewater especially Only when it passes through by ammonification and nitrification secondary treatment does it become through bacterial action. acceptable by standards that it is equal to natural river water Sewage Disposal Methods Treatment Plants Through sewer systems - standard in built-up areas (cities and industrial Work to separate the wastewater areas) into supernatant liquid and sludge On-site sewerage treatment - usually Supernatant liquid, after further found in residential, rural areas treatment, is then discharged to Chemical toilets - used by airplanes, rivers, waterways, oceans, and long-distance vehicles (trains, aquifers, while sludge is dried and caravans, buses) deposited into ponds and settling beds or used as a fertilizer Sewage Treatments On-Site Sewage Treatment Consists of primary (physical) and Multi-stage systems that collect, secondary (chemical and biological) treat and disperse water generated treatment by a home or business Two types of systems: Wastewater is treated and ○ On-site sewage treatment discharged to the soils rather than ○ Off-site sewage treatment collected and transported to a wastewater treatment plant Off-Site Sewage Treatment Steps of On-Site Wastewater Treatment Systems 1. Identifying the source - Discharge Usually for urban areas, where sources for residential areas include houses and buildings are arranged plumbing fixtures, toilets, laundry,  and dishwater; Commercial phosphates, dissolved oxygen, and wastewater comes from restaurants, residual chlorine levels are tested to manufacturing plants, and conform to the plant's NPDES permit businesses 8. Effluent Disposal - After meeting all 2. Collection and Storage of permit specifications, clean water is Wastewater - Solid rigid pipe collects reintroduced into the environment wastewater from plumbing fixtures and appliances, laid at a downward slope leading to the pre-treatment The Septic Tank Septic plant Tank System 3. Pre-treatment of Wastewater - Involves removing contaminants Private septic tank systems treat from the wastewater to prepare it for wastewater underground, used in final treatment, using components rural regions without municipal like trash tanks, septic tanks and sewage systems processing tanks Septic tanks break down 4. Final Treatment and Dispersal of biodegradable waste from a home's Wastewater - Final removal of or business's sewage system contaminants takes place and the Septic systems handle bathroom, water can be safely dispersed into kitchen, and laundry wastewater the environment, often through a using nature and technology gravity flow system Types of Septic Tank Systems Stages of On-Site Wastewater Treatment 1. Conventional System 1. Bar Screening - Removal of large 2. Alternative Systems: objects that can damage equipment ○ Aerobic Treatment Unit 2. Screening - Removal of grit through (ATU) a grit chamber ○ Mound 3. Primary Clarifier - Separation of solid ○ Sand Filter organic matter from wastewater ○ Peat Moss 4. Aeration - Air is pumped into a tank to encourage NO3 development Aerobic Treatment Unit (ATU) (from NH3) and provide oxygen for bacterial growth Break down solid waste using 5. Secondary Clarifier - Treated oxygen, producing "cleaner" wastewater is pumped into a wastewater than conventional septic secondary clarifier to allow any systems remaining organic sediment to settle Aerobic bacteria in the septic tank out need oxygen to grow and thrive, 6. Chlorination - Chlorine is added to decomposing household and kill any remaining bacteria in the business waste contact chamber 7. Water Analysis and Testing - Proper Mound pH level, ammonia, nitrates,  Used when the drain field is elevated 2. Steel Septic Tank or there is little soil for treatment 3. Plastic or Fiberglass Septic Tank Employs a sand-filled mound atop natural soil over a drain field, to Concrete Septic Tank clean wastewater as it passes through the sand layer and into the Can crack, rust, or even separate soil due to low-quality concrete mix and inadequate maintenance Sand Filter Cracks allow waste to leak out or groundwater to seep in, causing Similar to mound systems, employs complications a layer of sand and a pump to cleanse and disperse wastewater Steel Septic Tank where soil is limited One of the most common septic The weakest and least popular systems used when conventional option, enduring only 20-25 years systems lack sufficient soil before corroding The steel tank lid may corrode and Peat Moss collapse under weight Used in systems that rely on peat Plastic or Fiberglass Septic Tank moss between the septic system's pump tank and drainfield More resistant to rust, corrosion, and Wastewater is mostly treated by the cracking than steel or concrete peat prior to entering the drainfield, But their lightweight construction beneficial in areas with limited soil makes them prone to structural depth or high groundwater damage How a Conventional Septic Septic Tank Design System Works Users and sludge removal intervals determine septic tank capacity, with Septic tanks are underground, sludge removal every 2 years watertight containers often built of 95-150 liters of human waste, concrete, fiberglass, or polyethylene including kitchen garbage, is The drain field is an open, covered produced daily trench dug into relatively dry ground, Septic tanks have 23cm brick or with perforated pipes to allow the RCC walls, 15cm cement concrete water to escape into the ground and 1:2:4 foundation floors, and all be absorbed, purified, and corners are rounded distributed throughout the soil before Impermo, Cem-seal, Acidproof, etc. entering the groundwater system are added to cement mortar at 2% by weight to prevent concrete Types of Septic Tanks leakage 1. Concrete Septic Tank  The septic tank floor slopes Quantity of water supplied = 120 x 1:10-1:20 toward the inlet side floor 20 = 2400 liters/day Considering 80% of water supplied Partition or Baffle Wall becomes sewage, the quantity of sewage produced = 2400 x 0.8 = A permanent partition may divide a 1920 liters/day septic tank above 2000 liters into Considering a detention time of 24 two chambers, with the first hours, the quantity generated during chamber's capacity double that of the detention time/tank capacity = the second 1920 liters Considering the deposited sludge Cover and Access Holes rate as 30 liters/capita/year and a Each septic tank compartment must cleaning period of 1 year = 30 x 20 x have a 445x610mm rectangular 1 = 600 liters access aperture or a 500mm circuit Total Required capacity of the tank = opening Capacity for sewage + Capacity for sludge = 1920 + 600 = 2520 or 2.52 Pipe Ventilation cubic meters Considering the tank's depth of 1.3 Septic tanks must have 50mm meters, the tank's surface area = ventilation pipes enclosed in a 2.53/1.3 = 1.94 m^2 protective mesh cage to keep Considering length to width is 1:3, mosquitoes out the Length x Width = 1.94 m^2, so B = sqrt 1.94/3 = 0.8 m Septic Tank Construction The dimension of the septic tank will be 2.412m x 0.804m x (1.53+0.3)m The tank's base must be watertight overall depth and sturdy enough to maintain the tank's weight, walls, and interior during earthquakes Waste Pipes Brick walls must be at least 200mm thick and plastered with a cement Smaller in size than the soil pipe due mortar ratio of 1:3; Stone masonry to the type of waste it receives from walls must be at least 370mm thick various plumbing fixtures Septic tanks have 75-100mm RCC Suspended materials found in the slabs on top, with 500mm manholes water waste include grease, lint, for inspection and desludging matches, hair, and garbage Designing a Septic Tank General Conditions for Good Waste Pipes Example: A small house of 20 people with a secure water supply 1. Making the right choice of materials from the municipal headwork at a based on the character of the waste rate of 120 liters/person/day and the service it is intended for  2. Conservative use of fittings to 1. Combined Drain - Receives ensure smooth flow discharge of sanitary waste as well 3. Right slope or grade of the pipelines, as storm water ideally 2% slope 2. Sanitary Drain - Receives the 4. Proper manner of joining pipes as discharge of sanitary domestic recommended by manufacturers waste only 3. Storm Drain - Conveys all storm Recommended Size of Waste clear water or surface water waste Pipes except sanitary wastes 4. Industrial Drain - Receives 1. Sink Waste - Minimum 38mm or 1 discharges from industrial equipment 1/2", but practice is to use 50mm or containing objectionable acid wastes 2" pipe 2. Slope Sink - 75 or 100mm for traps Determining the Size of House installed on floors, 75mm for traps Drain installed on walls 3. Scullery Sink - 50mm The Unit System is the most 4. Panty Sink - 38mm practical method, based on Fixture 5. Factory Wash Up Sink - 50mm Unit load discharges for sanitary 6. Bathtub - 38mm min to 50mm drain, or roof area that accumulates 7. Lavatories - 50mm major rainfall for storm drain 8. Shower Bath - 50mm No water closet shall discharge into 9. Urinal - 50mm a drain less than 75 mm or 3 inches 10. Laundry Tub - 38mm to 50mm pipe diameter, and no more than 2 11. Drinking Fountain - 32mm water closets shall discharge into 12. Lavatory Waste - 50mm any 75 mm horizontal soil branch, 13. Hospital Fixtures - 50mm house drain or house sewer Grade Slope of House Drain House Drain House drain must produce the That portion of the plumbing system necessary velocity and discharge that receives discharges of all soil capacity at certain inclination, ideally and waste stacks within the building, 2% slope, to attain scouring action and conveys the same to the House Exceptions may be made when the Sewer depth of the sewer line in relation to Can be installed underground, the depth of the basement floor is suspended below the floor or inside low, or for long sewer lines that the ceiling require lower pitch but not less than 1% Types of House Drain House Sewer  That portion of the horizontal 1. Reinforced Concrete Pipe drainage system, which starts from 2. High Density Polypropylene Smooth the outer face of the building and Interior terminates at the main sewer in the 3. PVC - Polyvinyl Chloride street or septic tank 4. High-Density Polyethylene Smooth The Main Sewer line is financed and Interior maintained by the government, and houses along the street with main Parts of a Drainage System sewer line are required to connect their house sewers to the public Inlets - Openings that allow sewer line stormwater to flow into the storm drainage system (curb opening, House Connection of House Sewer grate, slotted, combination) Culverts - Massive pipes that carry The house sewer pipe is connected stormwater underground to a local to the Main Sewer by boring a small pond, treatment plant, or other hole through the concrete pipe, destination using a sharpened steel chisel or Manholes - Openings to access electric drill confined spaces for inspection, The House Sewer pipe is connected maintenance and system upgrades to the Main Sewer entering at 45 Trunk Line - The main pipeline that degrees angle or directly from the carries the stormwater away top Classification of Storm Drains Size of a House Sewer 1. Inside Storm Drain - Located under Old practice was to use 150 mm or 6 the basement floor or within the in. diameter cement/vitrified clay walls of the building pipe for house sewer 2. Outside Storm Drain - Installed For plastic pipe or equivalent interior outside the foundation wall of the surface texture, the diameter can be building reduced to 100 mm, subject to 3. Overhead Storm Drain - Adopted standard rules when the street drainage is higher in elevation than the basement floor, to avail of gravity flow Storm Drain Sizing a Storm Drain The unit of the plumbing system that conveys rain or storm water to a Considerations: suitable terminal, normally discharged into a street gutter and Rainfall over a given period, whether carried to a natural drainage terminal constant or heavy showers Types of Storm Drain Pipes  Varying roof areas, slope, and Waste Stack Venting distance traveled before reaching Single-Stack Venting conductors Height of the building contributing to Trap Seal Loss velocity of water falling into vertical pipe conductors Main ways for trap-seal loss are Use of proper fittings and avoiding self-siphonage, induced-siphonage, short offsets and compression Can be caused by poor practice, not Grade Change of Direction following regulations, or improper pipework design and installation Storm drain installed with a slope of not more than 2% per meter run Retardation of Flow Combination of Y and ⅛ bend or a long radius fitting is appropriate for Retarded water flow inside the pipe any change in direction is the result of improper atmospheric conditions due to insufficient ventilation or incorrect installation of Plumbing Ventilation fittings Can be corrected by providing Plumbing vent, or vent stack, ventilation pipes to equalize or regulates the air pressure within the balance the air pressure inside the home's plumbing system plumbing installation Allows fresh air into the system, improving pipe drainage and water flow Soil Vent Pipe Why is Ventilation Necessary? Vertical pipe that removes sewage and greywater from a building, often Drainage and vent systems work attached to the exterior together to move waste and water Allows odors to be released above efficiently out of the home the building and facilitates aerobic Without proper ventilation, the sewage digestion systems work against each other, causing plumbing issues Drain Waste Vent (DWV) Venting Methods System Conventional Venting (Individual Allows air to enter the plumbing Venting) system to maintain proper air Common Venting pressure and enable the removal of Wet Venting sewage and greywater Circuit Venting Drain refers to water from fixtures, Combination Waste and Vent waste refers to water from toilets Island Fixture Venting Main Vent Factory Wash Up 50mm Pipe that runs from a plumbing Sink fixture up through the roof, allowing air pressure to escape the plumbing system Bathtub 38-50mm Unit Venting Vent that allows gases in the Lavatories 50mm sewage drainage system to discharge to the outside and sufficient air to enter, reducing air Shower Bath 50mm turbulence Types of Vents Urinal 50mm Individual Vent Stack Vent Vent Stack Circuit Vent Relief Vent Looped Vent Wet Vent Table: Recommended Waste Pipe Sizes Fixture Minimum Pipe Size Sink Waste 38mm (1 1/2") Slope Sink 75-100mm Scullery Sink 50mm Panty Sink 38mm