Septic tank 217773 225505712 2008-07-14T01:27:04Z 98.30.16.140 Honey slang is listed below, and not important enough to be on top. {| align=right |[[Image:Septic_tank_not_in_ground.jpg|thumb|right|A septic tank before installation]] |- |[[image:Septic_tank.jpg|thumb|right|The same tank partially installed in the ground]] |- |[[Image:Landpeople s cc8.PNG|thumb|right|Septic tank and [[septic drain field]]]] |} A '''septic tank''', the key component of a '''septic system''', is a small scale [[sewage treatment]] system common in areas with no connection to main sewerage pipes provided by private corporations or local governments. (Other components, typically mandated and/or restricted by local governments, optionally include pumps, alarms, sand filters, and clarified liquid effluent disposal means such as a [[septic drain field]], ponds, or [[Sphagnum|peat moss]] beds.) Septic systems are a type of On-Site Sewage Facility ([[OSSF]]). In [[North America]] approximately 25% of the population relies on septic tanks; this can include [[suburbs]] and small towns as well as [[rural]] areas. In Europe they are generally limited to rural areas only. The term "septic" refers to the [[Anaerobic digestion|anaerobic bacterial]] environment that develops in the tank and which decomposes or mineralizes the waste discharged into the tank. Adding a supplemental bacterial agent to the tank may accelerate the digestion of solids in the tank. Septic tanks can be coupled with other [[Onsite sewage facility |on-site wastewater treatment]] units such as [[biofilters]] or aerobic systems involving artificial forced [[aeration]].<ref>{{web cite | url = http://www.agwt.org/info/septicsystems.htm | title = Septic Systems for Waste Water Disposal | publisher = American Ground Water Trust | accessdate = 2008-05-20 }}</ref> Periodic [[preventive maintenance]] is required to remove the irreducible solids which settle and gradually fill the tank, reducing its efficiency. In most jurisdictions this maintenance is required by law, yet often not enforced. Those who ignore the requirement will eventually be faced with extremely costly repairs when solids escape the tank and destroy the clarified liquid effluent disposal means. A properly cared-for system, on the other hand, can last for decades and possibly a lifetime. ==Description== A septic tank generally consists of tanks between the size of 1,000 and 2,000 gallons (4000 - 7500 litres) which is connected to an inlet wastewater pipe at one end and to a [[septic drain field]] at the other. These pipe connections are generally made via a T pipe which allows liquid entry and egress without disturbing any crust on the surface. Today the design of the tank usually incorporates two chambers (each of which is equipped with a manhole cover) which are separated by means of a dividing wall which has openings located about midway between the floor and roof of the tank. Wastewater enters the first chamber of the tank, allowing solids to settle and scum to float. The settled solids are anaerobically digested reducing the volume of solids. The liquid component flows through the dividing wall into the second chamber where further settlement takes place with the excess liquid then draining in a relatively clear condition from the outlet into the [[leach field]], also referred to as a drain field, or seepage field, depending upon locality. [[Image:Septic Tank Pump Alarm System.jpg|thumb|right|Septic tank lift pump alarm system located in a house.]]The remaining impurities decompose in the soil, and the water is eliminated through [[percolation]] into the [[soil]], and eventually taken up through the [[root]] system of [[plant]]s or added to the [[groundwater]]. A piping network, often constructed in a stone filled trench (see [[weeping tile]]), distributes the wastewater throughout the field with multiple drainage holes in the network. The size of the [[leach field]] is proportional to the volume of wastewater and inversely proportional to the porosity of the drainage field. The entire septic system can operate by gravity alone, or where topographic considerations require, with inclusion of a lift [[pump]]. An [[Imhoff tank]] is a two-stage septic system where the sludge is digested in a separate tank. This avoids mixing digested sludge with incoming sewage. Also, some septic tank designs have a second stage where the [[effluent]] from the anaerobic first stage is aerated before it drains into the seepage field. Waste that is not decomposed by the anaerobic digestion eventually has to be removed from the septic tank, or else the septic tank fills up and undecomposed wastewater discharges directly to the drainage field. Not only is this bad for the environment, but if the sludge overflows the septic tank into the leach field, it may clog the leach field piping or the soil porosity itself, requiring expensive repairs. How often the septic tank has to be emptied depends on the volume of the tank relative to the input of solids, the amount of indigestible solids and the ambient temperature (as anaerobic digestion occurs more efficiently at higher temperatures). In general some septic tanks tanks may need to be emptied every six months while others every year depending on use. When emptying a tank, only a small residue of sludge should be left in the tank. Anaerobic decomposition is rapidly re-started when the tank re-fills. A properly designed and normally operating septic system is odour free and, besides periodic inspection and pumping of the septic tank, should last for decades with no maintenance. A well designed and maintained concrete, fibreglass or plastic tank should last about 50 years.<ref>{{web cite | url = http://cecalaveras.ucdavis.edu/realp.htm | title = Septic Tanks: The Real Poop | publisher = University of California Extension | accessdate = 2006-07-11 }}</ref> ==Potential problems== #Excessive dumping of cooking oils and grease can fill up the upper portion of the septic tank and can cause the inlet drains to block. Oils and grease are often difficult to degrade and can cause odor problems and difficulties with the periodic emptying. #Flushing non-biodegradable hygiene products such as sanitary towels and cotton buds will rapidly fill or clog a septic tank; these materials should not be disposed of in this way. #The use of [[Garbage disposal|waste macerators or grinders]] for disposal of waste food can cause a rapid overload of the system and early failure. #Certain chemicals may damage the working of a septic tank, especially pesticides, herbicides, materials with high concentrations of bleach or caustic soda (lye) or any other inorganic materials such as paints or solvents. #Roots from trees and shrubbery growing above the tank or the drain field may clog and or rupture them. #Playgrounds and storage buildings may cause damage to a tank and the drainage field. In addition, covering the drainage field with an impervious surface, such as a driveway or parking area, will seriously affect its efficiency and possibly damage the tank and absorption system. #Excessive water entering the system will overload it and cause it to fail. Checking for plumbing leaks and practicing water conservation will help the system's operation. #Even well maintained septic tanks release [[mucus]]-producing anaerobic gut bacteria to the drainage field. The mucus "slime" will slowly clog the soil pores surrounding the drain pipe and percolation can slow to the point where backups or surfacing effluent can occur. This slime is called biomat and such a failure is referred to as "Biomat failure"<ref>[http://web4.msue.msu.edu/4hycc/documents/M4HYCC2005finalPresentation.pdf Impacts of Septic System chemicals on public health, wildlife, and habitats/ ecosystems:<!-- Bot generated title -->]</ref>. #If the system is damaged or malfunctions, contact your local health or environmental authority before attempting any repairs. Improper repair can result in costly mistakes and potential health hazards. #Septic tanks by themselves are ineffective at removing [[nitrogen]] compounds that can cause [[Algal bloom |algae blooms]] in receiving waters; this can be remedied by using a nitrogen-reducing technology.[http://www.epa.gov/etv/verifications/vcenter9-3.html] ==Environmental issues== Some pollutants, especially [[sulfate]]s, under the anaerobic conditions of septic tanks, are reduced to [[hydrogen sulfide]], a [[odor|pungent]] and [[toxic]] gas. Likewise, [[nitrate]]s and [[Nitro compound|organic nitrogen compounds]] are reduced to [[ammonia]]. Because of the anaerobic conditions, [[fermentation (biochemistry)|fermentation]] processes take place, which ultimately generate [[carbon dioxide]] and [[methane]], both of which are known greenhouse gases. The fermentation processes cause the contents of a septic tank to be anoxic with a low [[redox]] potential, which keeps [[phosphate]] in a soluble and thus mobilized form. Because phosphate can be the limiting nutrient for plant growth in many ecosystems, the discharge from a septic tank into the environment can trigger prolific plant growth including algal blooms which can also include blooms of potentially toxic [[cyanobacteria]]. Soil capacity to retain phosphorus is large compared with the load through a normal residential septic tank. An exception occurs when [[septic drain field |septic drain fields]] are located in sandy or coarser soils on property adjoining a water body. Because of limited particle surface area, these soils can become saturated with phosphate. Phosphate will progress beyond the treatment area, posing a threat of [[eutrophication]] to surface waters.<ref>{{cite web | url = http://cru.cahe.wsu.edu/CEPublications/eb1475/eb1475.html | author = Craig G. Cogger | publisher = College of Agriculture and Home Economics, Pullman, Washington | title = eb1475 Septic System Waste Treatment in Soil | accessdate = 2006-07-11}}</ref> In areas with high population density, groundwater pollution levels often exceed acceptable limits. Some small towns are facing the costs of building very expensive centralized wastewater treatment systems because of this problem, owing to the high cost of extended collection systems. Too often, the efficient and economical alternative of a properly-designed decentralized wastewater treatment system is not considered. To slow pollution, building moratoriums and limits on the [[Subdivision_%28land%29|subdivision]] of property are often imposed. Ensuring existing septic tanks are functioning properly can also be helpful for a limited time, but becomes less effective as a primary remediation strategy as population density increases. Once polluted, groundwater is very slow to clean - thus urgent action is appropriate. The common expression ''the grass is always greener over the septic tank'' (which is also the title of an [[Erma Bombeck]] book) is technically incorrect. The grass is greener over the '''leach field''', which is better watered and has more nutrients than the surrounding land. However, it is not unusual to find better growth over the septic tank itself as well, particularly the end nearer the leach field. =="Septic tank" in slang== In [[Cockney Rhyming Slang]] (common in Britain and [[Australia]]) "septic tank" or, more commonly, simply "septic" or "[[seppo#S|seppo]]" is used as a [[pejorative]] [[Alternative words for American|word for an American]], based on a rhyme for "[[Yank]]". The pejorative nature of the term is further underlined by its referral to a container for storing human waste. The use of the nickname "[[seppo#S|seppo]]" in Australia is also derived from the preconception that all Americans are full of shit (like a septic tank). In an episode of the British panel show "[[Q.I.]]", [[Stephen Fry]] mentioned the [[neologism]] "listerine", from a mouthwash whose antiseptic properties made it suitable for rhyming slang use to refer to anti-Americans. The term [http://www.virtualnewarknj.com/memories/newark/newmanhoney.htm ''Honey wagon''] is a euphemism originally referring to a horse drawn wagon carrying a tank of liquid manure or sewage. Today a tanker truck equipped with a [[sludge]] pump to empty septic and conservancy tanks is also euphemistically known as a "honey sucker" or "honey dipper." The term "[[stink pipe]]" is a euphemism originally referring to a vent pipe used to remove odour from the septic tank piping system. ==See also== *[[Backwater]] *[[Biofilters]] *[[Bioreactor]] *[[Cesspit]] *[[Ecological sanitation]] *[[Grease interceptor]] *[[Latrine]] *[[Mound system]] (a type of septic system) *[[Outhouse]] *[[Perc test]] (Percolation testing for the capacity of soil to absorb water) *[[Pit toilet]] *[[Plumber]] *[[Plumbing]] **[[Domestic water system|Potable cold and hot water supply]] **[[Plumbing drainage venting|Traps, drains, and vents]] **[[Drainage|Rainwater, surface, and subsurface water drainage]] **[[Piping|Fuel gas piping]] *[[Sepsis]] *[[Septage]] *[[Sewage treatment]] *[[Sewer]] *[[Stink pipe]] *[[Waste disposal]] *[[Wastewater]] == References == <references/> ==External links== *[http://www.epa.gov/owm/septic/index.html EPA on septic tanks] *[http://listenv.homestead.com/files/septic.htm Dos, Don'ts & Problem-solving, at a range of costs] *[http://www.ferrocement.com/casa-ca8/ch8.en-ferroHouse-web.html How to design and build a ferrocement septic tank] * USEPA's [[National Small Flows Clearinghouse]], Morgantown, West Virginia, USA (http://www.epa.gov/owm/mab/smcomm/nsfc.htm) [[Category:Sewerage]] [[Category:Toilets]] [[Category:Waste treatment technology]] [[cs:Žumpa]] [[da:Septiktank]] [[de:Klärgrube]] [[es:Fosa séptica]] [[fr:Fosse septique]] [[nl:Septic tank]] [[ja:浄化槽]] [[no:Septiktank]] [[pl:Szambo]] [[pt:Fossa séptica]] [[sv:Septiktank]] [[zh:化糞池]]