Frequently asked Questions

A constructed wetland is a kind of swamp. Scientists have discovered that nature had long ago found a solution to clean dirty water; that happened in swamps, among other places. Scientists started studying what kind of processes took place in it and then they started thinking about whether we humans could optimize that as well. And that was possible! So a constructed wetland is actually a kind of swamp 2.0. You can't sink into it, you can't get wet feet in it, no mosquitoes can develop in it - because everything takes place underground. The usual constructed wetland is a sand body that is planted with marsh plants and in which the waste water is brought into contact with plant roots and micro-organisms and both ensure that waste is converted into harmless substances.

The size of a constructed wetland is determined by the amount of water that has to be purified and the degree of contamination thereof. That's why you have them in all shapes and sizes. But when we talk about domestic waste water, the rule of thumb applies: between 3 and 4 m² per person. So for a family of 4 people we are talking about 12 to 16 m², which is about the size of the space occupied by the patio table with chairs in the garden.

Because constructed wetlands can be made in all possible sizes and shapes (see previous question), it is not possible to just put a price on them. You can, however, say how the price is structured: engineering (calculating which system is appropriate for the specific location), the materials, their transport and the labor costs (both manpower and machine labour). And of course: the bigger the system gets, the more expensive it will be. However, the quantum principle does also apply: the larger the system, the cheaper it gets per head - or per user, or per m³ of purified water.

The building kits that we offer for the self-builders, as well as the Tiny Wetland kits, are competitively priced, because the engineering has been done. In that sense, they are 'off the shelf items' and can be attached to a fixed price. See https://www.ecofyt.nl/en-gb/for-whom/home-builders

Constructed Wetland do not stink. (Fortunately, otherwise we probably had nothing to do!) There is a clear reason for this: waste water indeed stinks, but mainly when it comes into contact with oxygen. Technically it is possible to prevent this. Most helophyte filters are constructed in such a way that the wastewater is introduced into the filter about twice a day. This happens in the top layer of gravel, which is porous enough to receive all the water, so that no puddles form. From the gravel layer, the waste water (which is spread over the entire filter) can quickly and easily sink into the sandy bottom.

A Constructed Wetland for wastewater treatment is not a swamp in the sense that you can wade through the mud. The top layer consists of gravel and the whole is without doubt sturdy (and dry) enough to walk over. However, we prefer not to enter the filter: the plants can be easily damaged (especially in spring when the young shoots emerge) and there are pipes (to distribute the water) just below the surface. Digging pits, by (pets) animals or children is therefore not allowed. Furthermore, of course, the gravel cannot be clean, in the sense that children should be allowed to play with it. Practice does show that a helophyte filter is not particularly attractive to children, there is not much to see. 

This question has a lot to do with the previous two: vermin means 1) mosquitoes and other annoying insects and 2) rats or mice. Swamps are attractive to most insects due to their extensive reproductive potential: shallow puddles, stagnant water, and shelter is what matters. However, the helophyte filter does not meet those conditions. No puddles form (see question 1) and the top layer dries so quickly that insect eggs or mosquito larvae simply do not find the desired environment. As for rats, there is not enough water for them to make it attractive. We have never heard from practice (or from literature) that mosquitoes, rats or mice have been affected by a Constructed Wetland. 

Natural systems (Constructed Wetland, raised infiltration beds and underground infiltration facilities) of the small-scale wastewater treatment plants cost considerably more space than the technical systems (Biorotors, Biotowers, biodiscs, etc.). But to say that it takes a lot of space? An area of about three to five square meters is required per person. For a family of four, you should therefore count on a reed field of approximately four by four meters. It may be said quietly that it is not a lost space; it can be a very attractive piece of greenery in the garden. It is not without reason that Constructed Wetland are praised for their “natural adaptability”.

It is not necessary. Certainly with the type we usually use (the Vertical Flow Constructed Wetland), it can be realized in all kinds of fantasy forms. The reason that most filters are rectangular is more of a financial matter: in this way you can work without losing foil material. There are no further restrictions.

It can be very nice to combine a Constructed Wetland with a pond. However, one must take into account that a Constructed Wetland, as we usually make it, has a depth of about 1.23 m. And that it is a condition that the water is released at the bottom. If you want a filter that is at the top (approximately) level with the pond surface, the cleaned water must first be collected in a sump and then it can be pumped to the pond. Another possibility is, of course, to realize sufficient declination between the filter and the pond, so that the water automatically flows to the pond.

No, from 1 January 2005 it has been regulated by law that waste water may not be discharged untreated into surface water (or into the soil). This is European regulation, from which no one should deviate. If waste water is produced somewhere and there is no connection to the sewage system, it is mandatory to use some form of (adequate) treatment.

In the beginning, some weeding should be done to give the young reed plants more chance than, for example, grass or nettles. (Incidentally, this is not so bad due to the fact that the top layer is made of gravel, young weeds are not yet very firmly attached). The technical part must also be checked annually: check the pump and, if necessary, clean it, spray the pipes on the reed field and check the pre-treatment wells (septic tank and grease separator) for the thickness of the deposited material. For a reed bed for a family, it is usually enough for two to four hours (per year) for maintenance. Emptying the septic tank and grease trap is something that should be done about once every seven years. Furthermore, should there ever be a malfunction, you (especially) must also contact us. We keep a report on every project we have completed and in our care, also for minor faults.

Yes, since 2010 we have the possibility to expand our control box with the possibility to send an SMS in the event of a malfunction (including the exact type of malfunction). And you can choose: send the SMS to you or to us - or to both.

Most filters that we install have a pump to inject the water into the filter. That is why there is need for electricity. However, where almost all technical wastewater treatment systems work with (almost) continuously rotating parts, in a Constructed Wetland the pump is used twice a day only, for no more than about five minutes. This means that for a domestic situation the electricity costs per year are only about fifteen euros. (Instead of about € 100, - up to € 200, - for the technical systems!)

Yes, and the reason is the following: it is not so much the reed plants that do the purifying work, but the bacteria that live in the soil. In winter, the reed dies above ground (not the roots, reed is a perennial), but the bacteria continue to do their job. The condition they impose is that the soil temperature does not become too low. And it is precisely maintained because waste water ends up in the filter every day, which is often still somewhat lukewarm due to, among other things, the use of showers or washing machines. And that the system always continues to work has been proven in practice, it even applies in winter with an Elfstedentocht! (Google that , if you have no clue! ;-)

Planting reed can be done in two ways: root cuttings or potted plants. The most favorable time is always March - April, but (much) later is always possible, for root cuttings, reasonable results can be achieved until August, for potted plants it can be done all year round. The preference for March / April means that the plants will develop immediately that year, the later in the season, the more the expectations have to be shifted to the following summer. Root cuttings can be even more vigorous than pot plants, the most sensational growth in the first year we have achieved with cuttings, but they are also much more sensitive to dehydration (after harvest they must be protected from dehydration and planted as soon as possible). The potted plants are much easier in that.

Yes, of course. We can also say that there is no small-scale system that works as well and efficiently and sustainably as the Constructed Wetland. There are hardly any other systems that can meet the strictest requirement; IBA class IIIb… Nevertheless there are sometimes employees of municipalities and / or water boards who do not have as much confidence in Constructed Wetland…. Well, there are still people we don't reach… .. But by law it IS a recognized system and it has been officially praised for its efficiency. 

We dare not exclude that! Please don't think that a Constructed Wetland is "just a bucket of sand where you put reed plants." However, if you want to do a (large) part of the construction yourself, you can also find a good partner in us; we have no trouble assisting you with advice & assistance or with only advice! We can of course also help you in choosing the right materials. In fact, we have put together three construction kits for the do-it-yourselfers: the smallest is for 1 to 3 people, the middle one for 4-5 people and the largest for 6-8 people. We work together with, amongst others: tinystee.nl The Tiny House specialist) and groenebouwmaterialen.nl (the specialist in environmentally friendly, sustainable building materials where other specialists, self-builders and construction companies can turn to for materials and advice).

The construction kits contain, in addition to all components to ensure that these Constructed Wetlands meet the highest class (IBA 3b), a very thorough manual to guide you through the construction process. And then there is also the possibility to build yourself, but also to hire an ECOFYT specialist for one or more days.