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FAQ Rainwater

What is greywater?

Greywater is the water that comes from sinks, bath and shower. However, the term greywater or gray water is often used incorrectly. People often speak of a gray water system while referring to a rain water system. So for the sake of clarity: a rainwater system uses water from a roof, a gray water system uses gray water that comes from a bath, shower or sink.

What is rain water?

Rainwater is all the rainwater that comes out of the sky during precipitation. So rainwater is more than just rainwater, it is also the rain melting water that comes from hail and snow. We use rainwater for rainwater systems. We do not use rainwater that comes from parking places and the street in a rainwater system, so only rainwater that flows from a roof.

What is household water?

Household water is the water that can be used for everything except drinking water applications. Consider, for example, water for your washing machine, garden watering, cooling water and toilet flushing. The concepts of rainwater and household water are often confused. It can sometimes be the same but that is not always the case.

What is black water?

Black water is a term we use when we refer to household wastewater, which includes water used to flush the toilet. Black water is considerably more difficult to reuse than, for example, rain water or gray water. That is why we see significant in Western Europe.

What is a rainwater tank or rainwater well?

Rainwater tanks provide for the storage of rainwater so that there is sufficient rainwater available for the rainwater system in case of drought. After all, a rainwater system that runs frequently on drinking water is unprofitable. Therefore always calculate the optimum volume before installing a rainwater tank. A rainwater tank should be able to meet the water requirement for around 24 days in order to be able to bridge longer periods of drought. GEP is happy to advise you in this, you can also make a calculation online in the GEP calculation module. GEP supplies various types of rainwater tanks. The plastic tanks are available in cylindrical form but also in square flat tanks. The concrete versions are usually referred to as rainwater wells and are round or oval-shaped. In addition to the concrete and plastic rainwater tanks, GEP also makes water bags that are perfectly suitable for crawl spaces under homes.

What is a break tank?

A break tank, also called a break tank or disconnection tank, is a reservoir that is placed between the water meter and the “dangerous” taps within a building. That is, the tapping points that are classified as category 5 water. These tapping points must be secured by me- ans of an AA interruption or an AB interruption. This is laid down in the EN1717 standard, those who want to know all the details can consult the relevant standard via the following link. The bottom line is that it is prevented, for example that rainwater, the water supply network from becoming polluted as a result of possible backflow of rainwater. The break tank therefore serves as a safety buffer, this buffer ensures that the polluted rainwater cannot flow back. A break tank is used when a break in the water pipe is desired or required.

What is a rainwater pump?

A rainwater pump is used for the transport of rainwater. The rainwater pump is the heart of every rainwater system. The rainwater is sucked up by the pump and then pumped further to the drainage points within the plot. These taps can be: toilet flush, garden taps and washing machine. There are also pressure submersible pumps for rainwater, these do not suck up the rainwater from the well, but they press it out of the rainwater tank. Pressure submersible pumps are therefore submerged. There are also “normal” submersible mpumps for rainwater. They are suitable for pumping rainwater, but they do not bring much pressure. So they are suitable for rainwater drainage, think from a basement or pump sump, but not suitable for connecting toilets or taps because there is hardly any pressure on the pipe. It is therefore important to carefully consider where and for what you want to use the rainwater before choosing a rainwaterpump.

Usefulness of a rainwater filter?

The rainwater must first be filtered before it is stored in a rainwater tank or well. The emphasis is on “first” a filter, then the rainwater only in the rainwater tank to be able to use it. Sometimes rainwater filters are placed in the pressure pipe, so after the pump, but that does not bring optimum water quality. It is of great importance for the quality of the rainwater to ensure that as much organic load as possible has been filtered out before the rainwater is stored in the rainwater well. If this step in the filtration is “forgotten”, the organic pollution is “decayed” on the bottom of the rainwater tank, with all its consequences for the water quality. The Trident filters from GEP ensure that the dirt particles in the rainwater tank are separated before the clean rainwater is stored in the tank. So in that respect the rainwater filter is the most important part of a rainwater system, so we like to talk about “the heart of the rainwater system”.

How do you know what size of rainwater tank you need? (tank volume)

An average tank capacity contains around 3,000 or 4,000 liters. However, this must be calculated. In Flanders, the volume is a legal requirement, which is generally higher than the calculated volume. This calculation is mainly based on the consumption and the roof surface of the building. Naturally, GEP can calculate this for you, and GEP also has an online calculation module where you can calculate your rainwater system yourself. This module calculates how large the pump should be but also what size of rainwater tank is required. If the volume of the rainwater tank is determined in the context of BREEAM, then what 5 indicates that it must be possible to buffer 50% of the consumption or 50% of the collection for 18 days. See also BREEAM for this. GEP is happy to help you make a calculation for this.

What about rainwater systems at large companies, or for example large schools?

The larger the roof surface, the more rainwater can be collected. A huge amount of drinking water can be saved here. So a rainwater system is not only for residential construction, but also for utility and industrial construction. After all, consumption is often higher here, especially for applications where expensive drinking water quality is not required, such as flushing the toilets. So here the rainwater can be used perfectly in the many toilets. Feel free to contact GEP for a complete design of a rainwater system. Of course you can also make a calculation of the rainwater system online.

How much drinking water do I actually use?

The average water consumption per family of 4 people is around 169m3 per year. Most of the drinking water goes on in the shower, the toilet flush and the washing machine. These are applications where no expensive drinking water quality is actually required. With the collection and use of rainwater through a rainwater system a lot of drinking water could already be saved. The following link provides an overview of the consumption of drinking water of an average Dutch family. Source: www.gemiddeldwater

What is a rainwater system?

A rainwater system is simply a system that collects rainwater and then prepares it for use. The use of rainwater can be used for different applications, it can be used for toilet flushing, for your washing machine and garden watering and for example washing your car. Use of rainwater for showers and dishwashers is generally discouraged. In terms of technology, it has come to pass that the KIWA and
Belgaqua rainwater system is certified in accordance with the mandatory EN1717 standard.

What are the advantages of a rainwater harvesting system?

With a rainwater harvesting system, you can save up to 55% of your drinking water needs. This not only saves you money, but also contributes to an environmentally conscious society. By storing the rainwater you take pressure from the canals during heavy rain events and thus prevent flooding. Rainwater is free, soft and contains no lime. You are in a good mood, both in the sun and in the rain. :-)

Can I wash my clothes with rain water?

Excellent clothing can be washed with rain water. In fact, it is better than drinking water. Rainwater is soft, contains no lime and is ideal for washing clothes. An additional advantage is that less detergent is also required.

What is rainwater infiltration?

Rainwater infiltration is increasingly being used. It is the penetration of rainwater into the ground instead of into the sewer. Most parts of the city consist of paved surface. All rain water that falls on roofs, sidewalks and streets is drained directly through the sewer system. Rainwater infiltration through dry parts of the subsurface is a good method. In many parts of the Netherlands this is impossible due to the high groundwater level. Rainwater infiltration can be done in various ways. Rainwater infiltration can make an important contribution to the recovery of groundwater supplies and the prevention of drying out. You are also working on uncoupling rainwater at the same time. GEP Rainwater offers you the right rainwater infiltration solution!

What is a submersible pump?

Submersible pumps or clock pumps are pumps that are completely immersed in the rainwater to be pumped. Submersible pumps ensure that the water in which the submersible pump is submerged is pumped away. This type of submersible pump is mainly used for: lowering groundwater, pumping up groundwater for drinking water or extinguishing water, pumping away drainage water, effluent, waste water and for reusing rainwater.

How does a submersible pump work?

The water is drawn directly into the pump via the suction grille at the bottom of a submersible pump. Then the submersible pump pumps the water through the pump housing but the connection. Here the water can leave the pump, to drain points within the plot in this case. The pump must be immersed in the water in the tank, or: the storage. In manual mode, submersible pumps cannot run dry due to a lack of rainwater. Submersible pumps are screwed to work, then insert the plug into the socket and the submersible pump can be started.

What is a drainage plate?

A drainage plate is a plate that drains rainwater to a rainwater collection tank. These drainage plates ultimately ensure a better drainage of the rainwater. A drainage plate ensures optimum soil condition and prevents flooding. A drainage plate can drain around 240 liters of rainwater per square meter per minute. There is horizontal drainage through pipes or plates and vertical drainage through a deep hole in the ground through pipes or real sand piles.

Wat is het nut van een breaktank?

Een breaktank, ook wel breektank of disconnectietank genoemd, voorkomt verontreiniging van de waterleiding. De afgelopen jaren is er steeds meer aandacht gekomen voor de veiligheid van technische installaties, met name voor de waterleiding. Er is steeds meer aandacht voor legionella ontstaan. Daar zien we tegenwoordig vaak dat er preventieve maatregelen genomen worden die gericht zijn op het bestrijden van legionella. Maar er worden ook steeds meer beveiligingen geplaatst die ons drinkwaternet beveiligen tegen verontreiniging, de zogenaamde breaktanks. Al deze breaktanks dienen allemaal een belangrijk doel; het voorkomen dat er verontreinigd water in ons drinkwatersysteem terecht komt. Oftewel: ze zorgen voor veilig drinkwatersysteem.

Wat is de noodzaak van een breaktank?

Er is een Europese norm die beschrijft hoe onze waterleiding beveiligd dient te worden, dat is de EN1717. Deze norm is uiteraard ook in Nederland verplicht en deze maakt onderscheid in 5 verschillende waterkwaliteiten, de zogenaamde vloeistofklassen. Deze varieren van klasse I tot klasse IV. De belangrijkste reden om een breaktank toe te passen, is om te voorkomen dat er vervuiling van het waterleidingnet optreedt door aanwezigheid van stoffen bij terugstroming van het water. Een breaktank is een beveiliging voor vloeistofklasse IV en dient te worden toegepast waar er met drinkwater en met afvalwater, rioolwater, veevoederbakken, zwembadwater en regenwater gewerkt wordt. We zien breaktanks in de praktijk daarom vaak bij slachterijen, mortuaria, tandartspraktijken, operatiekamers, tuin beregening, irrigatie, laboratoria, drinkwaterbakken voor vee, autowasserettes, wasserijen, etc.. En uiteraard zien we breaktanks op plaatsen waar men stoffen toevoegt aan water, zoals bijvoorbeeld antibiotica of chloor. Dus feitenlijk zijn er veel praktijksituaties waar breaktanks toegepast worden.

Wat zijn breaktanks?

Een breaktank is een beveiliging van de hoogste categorie, het is een vrij drastische maatregel want feitelijk onderbreekt de breaktank de drinkwaterleiding van alle aftappunten volledig. Een breaktank is een reservoir dat geplaatst wordt tussen de watermeter en de aftappunten. Op dit reservoir zijn dus niet enkel de aftappunten aangesloten maar ook de drinkwaterleiding. Aansluiting van die betreffende drinkwaterleiding is slechts onder speciale voorwaarden geoorloofd. In theorie zijn er drie uitvoeringen breaktanks die toegestaan zijn. Daarvan worden er in Nederland en Vlaanderen twee in de praktijk toegepast. Dat zijn de AA en AB-beveiligingen. Beide zijn atmosferische onderbekingen waarbij er geen water terug kan stromen richting de drinkwaterleiding.

Wat is een type AA beveiliging?

De Europese norm EN1717, min of meer de opvolger van het oude werkblad 3.8, omschrijft een AA beveiliging als een ‘atmosferische onderbreking met vrije uitloop boven de rand’ Deze vrije uitloop is een permanente onderbreking tussen het laagste punt van de drinkwaterleiding en het hoogste overlooppeil. Simpel gezegd is het een een tank waar wel drinkwater in kan stromen maar nooit meer terug. Niet als gevolg van zuiging maar ook niet door druk. Dergelijke type AA beveiligingen zijn bekender dan menigeen denkt. In vrijwel iedere cv-installatie zit altijd een klein trechtertje onder het overdrukventiel dat loost op een afvoer. Dat is een AA beveiliging.

Wat is een type AB beveiliging?

Een AB beveiliging lijkt op een AA beveilinging maar is iets gecompliceerder van opbouw. Het is nemelijk een watertankje (breaktank) met een vrije overloop. Deze zogenaamde AB-uitloop is een verticale en permanente onderbreking tussen het laagste punt van de voedingsopening van de drinkwaterleiding en het overloopniveau in het breaktankje. De norm omschrijft dit als ‘atmosferische onderbreking met niet-ronde overloop’ De overloop mag dus niet cirkelvormig zijn en dient ‘het maximum intlaatdebiet kunnen afvoeren onder foutcondities bij een positieve druk.’ Dergelijke beveiligingen zien we niet zo vaak binnen de woningbouw maar ze kunnen hele praktische oplossingen bieden. Zeker in combinatie met een pomp voor de drukverhoging kunnen hele compacte en normgerechte beveiligingen gerealiseerd worden.

Zijn er alternatieven voor breaktanks?

Over de alternatieven voor een breaktank kunnen we kort zijn; die zijn er niet! In de installatietechniek worden veelvuldig de bekende EB, EA en BA kleppen in de drinkwaterleiding gebruikt maar die zijn niet toegestaan voor water dat onder de categorie 5 valt. Kortom: bij categorie 5 water moet altijd een breaktank toegepast worden, aan u de keuze of dat een breaktank type AA of AB is.