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Glossary
Absorption pitAbsorption fieldActivated carbon filterAeration tankAnaerobic batch reactorAquarium aeratorArtificial wetlandBEVBiochemical oxygen demand (BOD5)Biocompatible waterBiocontrolled litter toiletBioelectronics of Vincent (BEV)BioenergyBiofilmBioLitter Toilet (BLT)Biomass energyBioreactorBOD5Black waterBLTChemical oxygen demand (COD)CisternCODCompostingCompost binCompost boilerConductance meterConstructed wetlandConventional sanitationDeep-bedding housing systemsDeep-litter housing systemsDejectaDispersal drainDrainage wellDry toiletEAUTARCIEEAUTARCIE systemEcological sanitationECOSANElectrolyteEnvironmental performanceEutrophicationFilter pitFirst flush water diverterGreywaterGreywater batch reactorHumanureHumanure toiletHumusHydrophor systemInhabitant-equivalentInnocuous waterJean Pain methodLagooning purification systemLeaf interceptorMesophilic bacteriaMicrofiltrationNanofiltrationOxidantOxidation-reductionOxidising agentPedogenesisPeri-urban zonespHPhoto-purificationPhyto-purificationPlanted soilbox filterPlanted trench filterPLUVALORPLUVALOR systemPotable waterPopulation-equivalent (PE)Purification efficiencyRainwater harvestingRamial chipped wood technique (RCW)RedoxReducing agentReductantReverse osmosisrH2RhizosphereSAINECOSAINECO systemSanitationSawdust toiletSedimentation tankSewageSoakawaySoil Moisture regimeSulphonatesThermophilic bacteriaTRAISELECTTRAISELECT systemWastewater Wastewater treatment Water closet (WC)Water tableWater tank level gaugeWaste stabilization pondWCWell-pump systemWetlandWetland finishing treatment pondFAQ'sDocumentationLast update: 2017-05-10
Glossary
Developed, adapted and translated by André Leguerrier on the basis of Joseph Országh's writings.
Absorption pit
A pit, trench or well that is usually a few meters deep, filled with permeable material and receiving treated wastewater that will percolate into the ground. When the water table is deep enough and soil permeability permits, an absorption pit constitutes an efficient and inexpensive alternative to a dispersal drain for the treatment of greywater, after its prior treatment through an anaerobic batch reactor. As such, the absorption pit is the end-component of a simple greywater dispersion system, as an alternative to a dispersal drain. Never discharge black water into an absorption pit.
Absorption field
A planted field that is reserved for the dispersion and infiltration into the ground of stormwater or treated greywater. Infiltration of urban residential greywater using this technique constitutes an urban-scale equivalent to the absorption pit or dispersal drain in single home applications of a greywater treatment system. Treated this way, the entirety of water used by a household is returned to groundwater reserves. The water cycle thus remains unperturbed. This option is useful in dry regions.
Activated carbon filter
A type of water filter that removes impurities composed of organic molecules, such as pesticide and hydrocarbon residues, detergents, etc. For potable water production, this filter also helps improve taste: considering a concrete cistern, any potential taste of cement is altogether removed. It also eliminates any eventual colouring of the water (yellowish) that could come from sediment fermentation. To prevent bacterial development amongst the activated carbon granules, the filtering component is treated with silver ions. Filtration is thenceforth defined as bacteriostatic. In a PLUVALOR System, an activated carbon filter is not necessary or useful to treat the entirety of water issuing from the well-pump system. Activated carbon filtering should be reserved solely for potable water production, by placing it downstream from the microfiltration system's ceramic filter. Some of the commercially-available ceramic filter systems come already equipped with a bacteriostatic activated carbon filter.
Aeration tank
A small underground holding tank placed downstream from the anaerobic batch reactor, equipped with an aquarium aerator, to make greywater purification more efficient and reduce greywater odours at the system's outflow. This is a necessary component of the TRAISELECT System.
Anaerobic batch reactor
A two-compartment underground tank that is used as a bioreactor to treat a household's greywater effluent by holding it for a minimum 2 to 3 weeks during the process. It works biologically whereby anaerobic bacteria will thrive due to the normally warmer greywater temperatures. These bacteria will in turn decompose grease, detergents and soaps contained in greywater, thereby dramatically reducing the pollutant load at the outflow of the tank. This is a fundamental component of the TRAISELECT System.
Aquarium aerator
Aquarium aeration equipment that is useful for the control of odours in a rainwater cistern. The same apparatus can also be used to reduce odours from treated greywater effluent issuing from a anaerobic batch reactor. The aeration set-up must also include a bubble diffuser, to be placed at the bottom of the tank.
Artificial wetland
See Constructed Wetland.
BEV
The acronym for Bioelectronics of Vincent
Biochemical oxygen demand (BOD5)
The amount of oxygen used up by microorganisms as they decompose organic matter contained in water, measured after 5 days of bacterial oxidation. Testing for BOD is done to assess the amount of organic matter in water, especially in the context of wastewater management.
Biocompatible Water
Concept proposed by Joseph Országh in 1995 based on BEV criteria, which defines drinking water that conforms to values different from those of legally-compliant potable water, the prolonged consumption of which does not represent a health risk. It is weakly mineralized (less than 250 mg/l), lightly acid to neutral (pH between 5 and 7.5) and chemically « indifferent » or neutral (rH2 below 29). These values are much stricter than for legally potable water. Yet, biocompatible water may also contain a few faecal-contaminated bacteria (less than a dozen per 100ml) and over a hundred common germs. This bacterial content is very well tolerated by the human organism.
Biocontrolled litter toilet
An earlier designation for the BioLitter Toilet.
Bioelectronics of Vincent (BEV)
A multidisciplinary scientific theory situated at the crossroads of electrochemistry, thermodynamics and biology. It is a scientific branch that was developed in the 1950's by Professor Louis-Claude Vincent. His research revealed a set of optimal values that were determined to be the most biocompatible for the human organism. It is based on four postulates, which centre upon correlations that exist between proton and electron exchanges in water and its biological properties. By applying the BEV theory, Joseph Országh first proposed a definition for biocompatible water in 1995. Measurement of the three key bioelectronic values (pH, rH2, and electric conductivity) is but the starting point for various applications in fields as diverse as medicine, metallurgy, and the agro-food industry. Since Professor Vincent's death in 1986, BEV has made some headway, mainly theoretical, yet little known in scientific spheres. On the basis of Louis Kervran's theories on biological transmutations, a French biologist, Daniel Pinon, formulated a theory that explains the process of cancer formation, as well as the healing of cancer by the use of medicine that acts upon blood's bioelectronic attributes.
Bioenergy
A neologism for Biomass Energy.
Biofilm
A relatively thin bacterial layer that lines the walls of tanks and conduits containing water that has not been chemically disinfected. When the stored water is exposed to light, the biofilm takes on a green colour, due to the presence of algae. A biofilm is indispensable to maintain the stored water's biological equilibrium. Water that has been polluted with detergents, soaps and fats is spontaneously purified thanks to the development of a biofilm. Initially turbid water clarifies to eventually become crystal clear. This process is much quicker in the presence of daylight. In a rainwater cistern, the biofilm ensures good water conservation. This is also the case within reverse osmosis tanks or canisters. Water that comes into contact with a biofilm can sometimes contain many hundreds of commonplace bacteria per 100ml. These bacteria are quite inoffensive. Yet to eliminate this « problem », some will occasionally choose to treat their reverse osmosis unit with diluted hydrogen peroxide.
BioLitter Toilet (BLT)
A third-generation dry toilet that is actually a collecting device that requires composting at a separate location. It requires the addition of cellulose-rich litter to the toilet contents immediately after toilet use, thereby inhibiting odours. But most importantly, this set-up aims to reclaim the entirety of human dejecta by restoring them as humus into the environment to renew the process of soil formation. In this sense, source-separation of urine and faeces is regarded as regrettable wastage, and a source of pollution.
Biomass energy
Also called Bioenergy. The intrinsic energy embodied in organic matter that composes the tissues of plants and animals, which is released when chemical bonds are broken by microbial digestion, combustion or decomposition. The energy in biomass is derived from solar energy that has been stored directly in plants through the process of photosynthesis and indirectly in animals that participate in the food chain originating with plants. Biomass is therefore regarded as a renewable energy source. Although current worldwide efforts aim to convert biomass into biofuels for combustion purposes (to generate heat, electricity, transportation fuels, etc.), microbial digestion of biomass to generate heat (via composting) is herein propounded as a more sustainable ecological approach.
Bioreactor
Any device or system that supports a biologically active environment. For greywater, see Anaerobic batch reactor.
BOD5
The acronym for Biochemical Oxygen Demand.
Black water
Wastewater from WCs and urinals, including faecal water. Unlike greywater, black water contains lots of nitrogen (98% of urban wastewater comes from WCs) and lots of faecal bacteria contamination.
BLT
The acronym for Biolitter Toilet.
Chemical oxygen demand (COD)
A measurement of the overall pollutant load in terms of chemically oxidisable (degradable) solids, especially in the field of wastewater management. Unlike BOD, COD measurements are taken by chemical oxidation in controlled standardized conditions.
Cistern
An underground water-storage tank, built of concrete or limestone/concrete masonry to ensure an ideal mineral balance in harvested rainwater. The underground location minimizes temperature fluctuations and improves water conservation. The cistern will include a distinct sedimentation compartment within, or a remote sedimentation tank, located upstream from the storage tank. Actually, a properly conceived rainwater cistern is none other than the artificial reproduction of a natural underground rock cavity in which water conserves well. Plastic or metal tanks are inappropriate for rainwater storage when considering whole house domestic reuse of harvested rainwater.
COD
An acronym for Chemical Oxygen Demand.
Composting
When properly done, composting is the artificial reproduction of natural humus formation. The gardener builds his compost by piling up his garden/yard residues, kitchen scraps and other cellulose-based litter. To these, it is best to add animal or human manure for a more efficient composting process and better-balanced compost.
In reality, there are three types of composting techniques: conventional composting for agricultural purposes (as described above), calorigenic composting to produce heat energy, and bioremediative composting, which aims to « de-pollute » soils. The first one combines nitrogen-rich animal biomass with carbon-rich plant biomass. The second one is limited to plant-based biomass, while the third uses other adapted combinations.
Compost Bin
The term « bin » herein applies to those built compost enclosures that are open to the ground. Worldwide, the « composting bin » is a carryall term for all types of compost enclosures, including closed containers or floored enclosures that prevent direct contact of the compost with the soil. These are improper compost enclosures: efficient composting requires that bins be open to the ground, to maintain the necessary migratory link between compost and natural soil for earthworms and other soil fauna that play a decisive role in the digestion of organic matter.
Compost boiler
An experimental system for pre-heating the home using thermogenic composting of a pile of RCW that has been first soaked (somewhat like the Jean Pain Method), to which is added BioLitter dry toilet effluent. A heat exchanger in the pile is connected to a floor heating system in the home, thereby providing a base heating during winter.
Conductance meter
Apparatus recommended to check a reverse osmosis filtration unit's good working order, so that can be determined for example, the exact moment the unit's membrane needs to be replaced (not too early, nor too late). This is especially recommended for those who produce their own biocompatible water from mains water supply. Water's electric conductivity is an important parameter in assessing its quality. Drinking water's conductivity is practically proportional to its electrolyte content (i.e. mineral salts). Water containing lots of mineral salts has a high conductivity. Weakly mineralized water is less conductive. Thanks to the almost linear relationship between salt content and conductivity, measuring the latter provides a good estimate of the residual dry matter in a water sample. One can find digital conductance meters on the market, which measure water's salinity or dry residual matter.
Constructed wetland
An artificial marsh or swamp, created for treatment of the anthropogenic discharge of wastewater, including sewage, stormwater runoff and greywater. Constructed wetlands can be designed to emulate natural wetland features, to act as biofilters, removing sediments and pollutants such as heavy metals from the water. They usually include impervious bottom linings, sand or gravel media and selected plants for purification.
Conventional sanitation
An anthropocentric approach to sanitation that is mainly concerned with hygienics – preventing the population's contact with pathogenic germs (sanitize = make clean) – at the expense of global environmental health. Wastewater is first collected and treated, than the liquid effluent is usually discharged in streams and rivers while the solids are usually eliminated by incineration, buried in landfills or spread on agricultural land. Environmental pollution is the outcome in all cases. Also see Wastewater Treatment.
Deep-bedding housing systems
See Deep-litter Housing Systems.
Deep-litter housing systems
Livestock and poultry housing systems where floors (usually concrete slabs, although it is clearly better to have exposed earth floors) are covered with litter (most often straw, but also wood, paper, shredded cardboard, plant weeds, etc.) that must be renewed on a daily basis. These systems represent about 5% of Western industrial livestock systems. They purpose to improve air quality for those people working in such facilities, but when correctly implemented, they also improve animal manure management and disposal by the application of the BLT's operational principles (combining plant-based cellulose with animal dejecta). Such housing systems are the solution to prevent pollution from liquid pig manure. In fact, agricultural reuse of impregnated and composted litter no longer pollutes waters with nitrates.
Dejecta
Animal or human excreta, including urine and faeces.
Dispersal drain
An underground pipe or network of pipes, which aims to infiltrate wastewater directly into the ground. This water dispersion technique is often used at the outflow of domestic on-site sewage facilities (such as septic tank + leach field systems). As these systems usually service conventional household sewage, infiltration of such treated water in soil will inevitably seep nitrates in groundwater, meaning that efficient black water treatment leads to greater groundwater pollution. Thus, the dispersal drain technique can only be appropriate for infiltration of sole greywater, and only after its prior treatment through an anaerobic batch reactor. It is an alternative to an absorption pit.
Drainage well
See Absorption Pit.
Dry toilet
Toilet that evacuates human excreta without it being discharged in water. Contrary to standard views, all dry toilets do not have the same impact on the environment. They can be classified along different criteria. For example, self-contained systems are usually classified as internal or external composting toilets. Dry toilets can also be classified by their method of operation, which has led us to define three generations of dry toilets.
EAUTARCIE
A neologism (pronounced « Oh-Tar-See ») for « Water Autarky », which abbreviates from the French « EAU », meaning « water », « AUTARCIE » meaning « autarky », or a self-sufficient system independent of outside influences.
EAUTARCIE system
One of the possible forms of Ecological Sanitation, which goes to the source of the problems with EAUTARCIE's version of ECOSAN (SAINECO), and proposes efficient, simple and inexpensive solutions, including rainwater harvesting for whole-house reuse (PLUVALOR System), selective treatment of dejecta through the use of BioLitter Toilets and composting, and selective greywater purification. In short, the concept of EAUTARCIE seeks to restore domestic water-related activities within nature's great cycles: water, carbon, nitrogen and phosphorus.
Ecological sanitation
A holistic reuse-oriented approach to sanitation that is concerned with sustainable environmental practices, notably reuse and recycling of water and biomass in a hygienically safe, closed-loop system. It is also concerned with the influence of sanitation installations on land's soil moisture regime. Unlike conventional sanitation, household water supply is also a fundamental concern in ecological sanitation. EAUTARCIE’s version of Ecological Sanitation ( called SAINECO in French) takes a more coherent approach than the carryall version of ECOSAN, with respect to the environment at large.
ECOSAN
A neologism for Ecological Sanitation.
Electrolyte
A substance, the ions of which are formed by dissociation of its component elements. This is called electrolytic dissociation, which can take place when mineral salts are dissolved in water, but also when salts are molten. An electrolyte always contains positively-charged cations and negatively-charged anions. A state of electro-neutrality is always maintained: the number of positive and negative electrical charges is identical. Dissolution of mineral salts, acids and bases in water always leads to their dissociation into component elements, but at varying levels. When dissociation is complete, the substance is called a strong electrolyte. A weak electrolyte is when most of the solute does not dissociate. The electric conductivity of a solution is directly proportional to the concentration of ions, after electrolytic dissociation.
Environmental performance
A set of environmental parameters that are taken into consideration within ecological sanitation. The evaluation of a sanitation system goes beyond the notion of simple wastewater purification efficiency to include a holistic assessment of its impacts on the environment, including energy and water consumption, air, water and land pollution, disruptions to the soil moisture regime, recycling versus waste production, land remediation, humus regeneration, etc.
Eutrophication
The excessive multiplication of algae in rivers, lakes or seawaters. It is the result of too high nitrate content in the water. The presence of small quantities of phosphates is equally necessary for eutrophication.
Filter pit
A rainwater collecting device that goes at the bottom of gutter downspouts to intercept leaves and other organic residues and prevent them from entering the rainwater cistern, thus reducing cistern maintenance. It is typically set in the ground at the convergence point of multiple downspouts, upstream from the cistern.
First flush water diverter
A rainwater harvesting apparatus or device designed to reduce contaminant influx in a rainwater cistern by diverting the first portion of the flow from a roof catchment at the start of a first rainfall, following an extended dry spell. The water volume that needs to be diverted is usually sized with respect to roof area and predicted flow rates. This device is installed upstream from the cistern, and downstream from roof downspouts.
Greywater
Domestic wastewater from bathing, dishwashing, laundry, and cleaning, as opposed to black water.
Greywater batch reactor
Humanure
A neologism coined by Joseph Jenkins (author of The Humanure Handbook), a fusion of the words « Human manure », to define human dejecta (combined faeces and urine) to be composted.
Humanure toilet
Joseph Jenkins' Humanure toilet corresponds to our definition of a BioLitter Toilet. The expression was coined by Jenkins in his book The Humanure Handbook). Initially called a « sawdust toilet », it was designed and developed by Joseph Jenkins at about the same time Joseph Országh developed his « Toilette à Litière Biomaitrisée », or BioLitter Toilet, in the early 1980's.
Humus
A brown organic matter resulting from the decay of plants and animals. It is a substance of great complexity that is always present in arable land and is the basis of soil's natural fertility and intrinsic structure.
Hydrophor system
A domestic supply water pump system that necessarily involves the use of a pressure tank to regularize household water pressure and reduce pump cycling. See Well-pump System.
Inhabitant-equivalent
See Population Equivalent (PE).
Innocuous water
Concept launched by Joseph Országh in 1996, as « innocuous water » (eau de qualité inoffensive), that can otherwise be considered as sanitary water. Even if it is not of « potable » quality, the accidental absorption of small amounts of such water can in no way be harmful to someone's health. It can be used for all domestic non-food purposes. Starting from harvested rainwater, innocuous water is obtained by simple 10-micron filtering. Innocuous water is a key element for sustainable water management worldwide. Its use derives directly from SAINECO's sixth principle, i.e. adapt water quality to its end-use. Using expensively-produced potable water for all domestic usages is totally unreasonable, and quite incompatible with sustainable water management practices. The concept of sanitary water at household faucets that is reserved for other purposes than human consumption is starting to make headways, even being qualified as a « new paradigm » in water management.
Jean Pain method
A compost-based bioenergy system developed by Jean Pain that produced 100% of his energy needs. By aerobic composting of brushwood, he heated water to 60°C at a rate of 4 litres a minute, which he used for washing and heating. By applying an anaerobic process to the same compost materials, he also distilled enough methane to run an electrical generator, cooking elements and his truck.
Lagoon
See Phyto-purification.
Leaf interceptor
A device that goes at the top of gutter downspouts to intercept leaves and other organic residues and prevent them from entering the rainwater cistern, thus reducing cistern maintenance and premature clogging of filters in the household's water purification system.
Mesophilic bacteria
Microorganisms that can live at temperatures from 20°C to 45°C, but that thrive around 37°C. In a biogas digester used to produce biomethane from organic waste, different types of bacteria can spontaneously develop depending on the temperature. Greywater sludge in a batch reactor usually generates temperatures that are ideal for mesophilic bacteria. When temperatures go above 40°C (even up to 50°C), other thermophilic bacteria appear. Starting from a given quantity of digestible matter, low-temperature digesters (with mesophilic bacteria) produce more methane, but at a much slower rate than high-temperature digesters (with thermophiles).
Microfiltration
A water filtering process that aims to remove bacteria below one micron in diameter. It does not modify water's chemical composition: solutes (dissolved salts) remain in water. Microfiltration removes contaminants from water by its passage through a microporous membrane, such as a ceramic membrane. It's an interesting alternative to chemical disinfection, without its drawbacks (i.e. the altering of water's electrochemical and biological properties). Microfiltration is often completed with additional activated carbon filtration in order to remove organic chemical pollutants (e.g. pesticides), bad smell and taste. When combined with activated carbon, microfiltration is useful to make rainwater (or any other chemically-suitable water) potable, when bacterial content is a concern. Microfiltration's usefulness is dubious if one wishes to improve mains water supply, since bacteria in such water have already been chemically killed off. It is totally useless for water that is chemically inadequate.
Nanofiltration
A water filtering process that is used to transform a highly polluted water source (or highly loaded with salt, as in seawater) into drinking water. It works by using high pressure to force a solution through a semi-permeable membrane. The membrane pores are slightly larger than those in reverse osmosis membranes, filtering particle sizes between 1 and 10 nanometres.
Oxidant
See Oxidising agent.
Oxidation-reduction
A double phenomenon in chemistry whereby one or more electrons are transferred from one ion, atom or molecule to another.
Oxidising agent
An oxidising agent is any substance capable of wrenching electrons from another substance. For example: when oxygen removes electrons from iron, iron oxide is produced, better known as rust. A common effect of oxidation is corrosion. When an oxidising substance effectively removes electrons in this way, it reduces itself in the course of the reaction. Reduction (or electron capture) is therefore the opposite of oxidation (see Reducing agent).
Pedogenesis
The process of soil formation, which goes through two stages. First, the fracturing and breaking-up of rock by erosion and freezing. Second, organic detrition resulting from all plant and animal life that thrives in topsoil. This natural process occurs in symbiosis with plant cover and soil organisms. It's the most important element of the biosphere to regulate a land's soil moisture regime. It takes only a few dozen years of intensive agro-chemical farming to totally destroy a dozen centimetres of arable soil that took thousands of years for plants and soil organisms to generate. In many cases, irrigating non-marshy land (rice paddies for example) ends up in the soil's destruction by salination – even if irrigation was done with unsalty water.
Peri-urban zones
Urban-rural fringe areas, where the countryside meets city peripheries or suburbs. In these areas, especially with single-family housing, the use of BLTs is technically feasible, and selective greywater treatment with the TRAISELECT system can be realized within the garden (or « yard » as it is known in North America).
pH
The acronym for « potential hydrogen »: a unit measure of the hydrogen ion concentration in a fluid. The range of pH values extends from 0 to 14, with 7 being neutral. Figures below 7 express increasing acidity, and those above 7 express increasing alkalinity.
Photo-purification
Photo-purification is an experimental greywater purification technique using daylight. It's been observed that soapy water that has been exposed to daylight and air spontaneously becomes clear. It eventually becomes crystal clear and can even meet the strictest discharge standards.
Phyto-purification
Often called phytoremediation. A constructed wetland system that is used to purify wastewater, or otherwise-polluted water (e.g. a lagoon or a waste stabilization pond). It complies with conventional sanitation imperatives: purify wastewater to obtain pure water, while disregarding everything else. Plants are called upon to absorb nitrogen and phosphorus (tertiary treatment). They also harbour bacterial colonies that play a specific role in the purification process. This is quite unlike TRAISELECT's wetland finishing treatment pond, which is a greywater filtering system. In the present case, we are talking about a more complex lagooning system, i.e. a combined wastewater treatment system, which can only be justified when persisting in the use of WC flush toilets. It is definitely not an Ecological Sanitation technique.
Planted soilbox filter
A variant of the planted trench filter (plants, drainage layer, impervious bottom), but built as a wooden box set aboveground. This solution is sometimes necessary when the wetland finishing treatment pond in which the planted filter must discharge is at a slightly higher elevation. When site topography permits, a trench in the soil is the better solution than the soil box.
Planted trench filter
A greywater filtration system that is a simple trench in the ground with a gravel or pebble drainage substrate for plants (without soil), and an impervious bottom lining. It is designed to allow greywater to filter through it while plants grow on top of it. In the trench substrate, the plant roots fill in the voids to form a sort of filtration sieve. It's important to point out that this is not a purification system using plants (or phyto-purification system). As greywater issuing from an Anaerobic Batch Reactor is nitrogen-free, plants don't absorb elements from the water. Their role is simply limited to physical filtering of suspended particles in greywater.
PLUVALOR
A neologism that has double meanings in French. It comes from the words « PLUie », meaning « rain » and « VALORisation », meaning « valorization » (or maximum reuse) combined in a word that suggests added value (« plus-value ») for the home. The suffix « OR » meaning « gold » is symbolical of water as a precious substance.
PLUVALOR system
A rainwater harvesting and recycling system for whole-house reuse, including drinking water. It is not a manufactured off-the-shelf system, but rather a concept accessible to all.
Potable water
Water that is generally considered fit for human consumption. Actually, « potable water » is a legal concept defined by law. Such water must comply with fifty or so physicochemical and microbiological parameters, yet it doesn't provide full safeguards for a person's health. Furthermore, legal limits for potable water vary between countries: the same water can be considered « potable » in one country, and not « potable » in a neighbouring country. In many countries, « potability » is imposed on all water intended for consumption. To establish legal limits on potable water's microbiological parameters, rather than doing epidemiological studies on the human organism's tolerance levels, legislators have simply imposed standards that in fact, make chemical disinfection inescapable. Such disinfection is detrimental to a person's health.
Population-equivalent (PE)
Definition for the amount of substance released by one person, legally defined (in Belgium) as representing 60 g/day of BOD5 contained in 180 litres of wastewater. This value is the mean value measured in combined wastewater, containing black water and greywater.
Purification efficiency
The measurement standard that is used in conventional sanitation to measure the degree of elimination of wastewater's pollutant load after having gone through a treatment system. It is calculated as the ratio between the pollutant load that enters a facility (as untreated water) and that which exits the same facility (as treated water), expressed as a percentage.
Rainwater harvesting
The process of collecting, filtering and storing water from rooftops, paved and unpaved areas for multiple uses. For whole house reuse, see the PLUVALOR System.
Ramial chipped wood technique (RCW)
A technique that seeks to emulate the way deciduous forests generate humus in soils, using branches from hardwood species that are chipped so as to be spread and incorporated in cultivated (and degraded) soil as an organic amendment. RCW constitutes one of the techniques available to regenerate damaged ecosystems, just like the Jean Pain method and the Paul Moray tree seeding technique.
Redox
Abbreviation of « reduction » + « oxidation », representing this double phenomenon in chemistry. See Oxidising agent.
Reducing agent
A reducing agent is any substance capable of yielding electrons, as opposed to an oxidising agent. Vitamin C or ascorbic acid is a reducing agent.
Reductant
See Reducing agent.
Reverse osmosis
A water filtering process that is often used for water. It works by using high pressure to force a solution through a semi-permeable membrane, retaining the dissolved salts and other solutes on the surface of the membrane and allowing the pure solvent to pass to the other side. It typically filters particulates, micro-organisms, organic compounds and ions above 0.5 nanometres in diameter. Unlike microfiltration, reverse osmosis modifies water's chemical composition. For each litre of filtered water obtained, such a system will use up – and reject – 3 to 10 litres of water used to backwash the membrane of its accumulated impurities. Nowadays, reverse osmosis is an inevitable technique for those who wish to get biocompatible water from mains water. It relinquishes (fortunately) some of the mineral salts in water after filtration. In contrast to what filtering system dealers will recommend, it is actually detrimental to place a primary filter upstream from the reverse osmosis unit to remove the last trace minerals from water.
rH2
A measurement of the available electrons in a fluid, providing an indication of oxidation / reduction potential. The range of rH2 values extends from 0 to 42, with 28 being redox neutral. Values above 28 are considered oxidizing (with respect to chemically pure water), below 28 reducing. The rH2 unit is one of the 3 key values considered by BEV.
Rhizosphere
The immediate neighbourhood of plant roots. This zone is where nitrates and phosphates are absorbed, but also where profuse bacterial denitrification occurs. In the absence of nitrogen (from black water), the soaps' and detergents' electrically-polarized macromolecules adsorb to soil particles, where they are decomposed by soil microorganisms into water and carbon dioxide. Infiltrating black water in the rhizosphere, or its dispersal in an enclosed trench where plants grow constitutes a much more efficient solution to protect the environment than the best activated sludge on-site sewage facilities available for single homes.
SAINECO
A neologism that comes from the French expression « asSAINissement ÉCOlogique » (or ecological sanitation). Yet it is different from ECOSAN.
SAINECO system
SAINECO, or EAUTARCIE’s version of ECOSAN is distinct from the popular ECOSAN concept, a « carry-all » expression that lacks consistent guidelines. SAINECO’s distinctive strongpoint is the integration of mutually dependent relations that involve water management, plant and animal biomass and their influences on climate change, as expressed under SAINECO’s six principles that aim to replace the 6 paradigms of current sanitary engineering.
Sanitation
Sawdust toilet
A variant of (or equivalent to) the BioLitter Toilet, functioning along the same basic biological (BioLitter) principle, but where sawdust is the preferred litter used, as developed by Joseph Jenkins (author of The Humanure Handbook). This expression has now been replaced by Humanure Toilet.
Sedimentation tank
A tank through which harvested rainwater or wastewater is passed so that suspended matter may settle to the bottom.
Sewage
See Black water.
Soakaway
See Absorption Pit.
Soil moisture regime
The manner by which precipitation is distributed on land, between surface run-off, infiltration in soil and evaporation. In this sense, the moisture regime is an integral part of the water cycle.
Sulphonates
Dodecylbenzene sulphonate and its derivatives constitute a class of synthetic detergents that have long been used for cleaning products, due to their relative low cost and high cleaning efficiency. In lab tests carried out in 1998 at the Université de Mons to measure greywater effluent from a greywater batch reactor, readings showed that these petrochemicals decompose twice as fast as traditional soaps. The petrochemical residues in such effluent is still more potentially harmful to the environment than traditional soaps (potassium/sodium stearates and oleates), when discharged in surface waters. On the other hand, when infiltrated into the ground, greywater's environmental impact is nil, whatever the detergents used, beit for treated or untreated greywater. This experimental fact has led to the formulation of Ecological Sanitation's 4th principle.
Thermophilic bacteria
Microorganisms that can live at temperatures from 40°C to 70°C, but that thrive around 55°C. In a biogas digester used to produce biomethane from organic waste, different types of bacteria can spontaneously develop depending on the temperature: mesophilic and thermophilic bacteria. Starting from a given quantity of digestible matter, low-temperature digesters (with mesophilic bacteria) produce more methane, but at a much slower rate than high-temperature digesters (with thermophiles)
TRAISELECT
A neologism that abbreviates from the French words « TRAItement SÉLECTif » (selective treatment).
TRAISELECT system
An extensive selective biological greywater purification system that involves an anaerobic batch reactor, which aims to treat grey wastewater distinctly from black water. It is not a manufactured off-the-shelf system, but rather a concept accessible to all.
Wastewater
Wastewater that is discarded either as greywater, black water, roadway stormwater or all combined. Domestic wastewater is usually limited to greywater and black water. In conventional sanitation, both these types of domestic wastewater are combined and treated together. In ecological sanitation, the impetus is to not produce black water. If black water must be produced, it will be collected and treated separately from greywater.
Wastewater treatment
Wastewater treatment is the process of removing contaminants from wastewater, including domestic sewage and greywater as well as roadway stormwater runoff. It aims to reduce environmental impact caused by wastewater disposal. To this end, conventional sanitation advocates discharging water that is as clean as possible, back into the receiving milieu, while disregarding other consequences (including those from sewage sludge, chemical treatment and the destruction of organic matter). Conventional treatment techniques consist in eliminating the pollutant load by biological oxidation, and by various chemical processes. The impetus is to discharge purified water back into surface water. In contrast, ecological sanitation does not aim to purify water, but rather endeavours to restore domestic activities within Nature's great cycles. Overall, this approach yields the least harmful environmental impacts.
Water closet (WC)
A flush tank toilet, simply called a flush toilet (as opposed to a dry toilet).
Water table
That part of the subsoil that is totally saturated with groundwater. It is an underground stretch of water located above impervious subsoil strata, forming a relatively horizontal layer, varying in thickness from a few centimetres to a few meters, and even hundreds of meters thick. It is replenished by infiltration from water precipitation. Water tables constitute our main groundwater reserves. In the absence of pollution, water quality is only influenced by the geological formations through which water percolates. Pollution (e.g. agricultural, industrial) takes a certain time to reach the water table. This « percolation time » varies from a few years to a few centuries, depending on the depth of the water table and the nature of the geological formations through which water migrates. A polluted underground water reserve can result from chemicals spread on land by farmers perhaps dozens of years prior. Remediation of a polluted water table is therefore a slow process. Even if pollution ceases immediately, the first signs of improvement will only show up at the end of the percolation stage. Comparatively, surface water such as in a river, can be « de-polluted » within a few years after the stoppage of pollution. And again, rainwater pollution immediately disappears after stoppage of atmospheric pollution. This means that in a foreseeable future, rain will constitute the sole source of quality drinking water worldwide, accessible to all. Furthermore, water from water tables, even when disregarding current pollution problems, is most often loaded with calcium carbonate (e.g. hard water) or other mineral salts. It is rarely biocompatible. To ensure sustainable agriculture and ecosystem preservation, replenishing water tables is indispensable. This can only be assured by sufficient ground plant cover, and especially by the presence of humus in soil.
Water tank level gauge
Apparatus used to measure a rainwater cistern's water level. Different technologies are available, such as float/weight/pulley systems, digital ultrasonic systems, or manometer-type capillary tubing assemblies, commonly sold by the fuel tank industry and becoming increasingly available in the rainwater harvesting industry. The latter usually indicate the fluid level as a percentage, 100% corresponding to a full cistern, 0% representing an empty one.
Waste stabilization pond
See Phyto-purification.
WC
See Water Closet.
Well-pump system
A household pump system that pressurizes and injects water from a cistern or a well in the home's plumbing system. When the set-up includes an intermediate pressure tank (with appropriate pressure-switch) to regulate water supply at the faucets, that is when we call it a « Hydrophor System ».
Wetland
An area of land the soil of which is saturated with water either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water. Wetlands include areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water (as defined by the Ramsar Convention)
Wetland finishing treatment pond
A greywater filtration system that is a constructed wetland designed as a simple decorative pond with a waterproof bottom lining. The pond is the finishing-off stage of the TRAISELECT System. In the pond, daylight is the primary bio-filtration catalyst.