Module III: Litter Traps and Clean Up Actions

General introduction

As explained in other modules, we want to get rid of litter and especially plastics in the environment. It threatens the environment of humans and animals, which themselves can also suffer damage. Of course, the best option for preventing damage from plastic is to prevent plastic from entering the environment. Modules 1 and module 2 provide insight into how plastic gets and ends up in our environment and which path it then takes there before it is either deposited locally or transported to the sea.

This module is about trapping litter that has landed in a stream or river and cleaning up the river embankments with coordinated actions once it arrived there.

To do so we prepared some videos, figures and informative texts which will help to answer the following questions:

• What are the essentials of litter traps in relation with river and embankment characteristics?
• How can you analyse the possibilities of litter traps with regard to effectiveness, operation, organization and costs?
• What ingredients will lead to successful clean-up actions along river banks? 

Litter traps & cleanups educational intro 

This introduction video is about the removing litter from the river itself and from the river banks because if we fail to prevent litter entering our river basins we have to act accordingly. See the video Educational introduction litter traps and cleanups. This video is made in the context of the educational program of the InterReg project LIVES. More information you can find at https://litterfreeriversandstreams.eu/education-program/

This module is structured in the following subchapters:

1. Capturing litter, where and how?
2. Functions and parts of litter traps
3. Variety in litter traps
4. What makes an effective clean up action?

The focus in this module, with reference to the LIVES project (Litter free rivers and streams), is on litter, more specific the macro plastics. Module 1 and module 2 discuss definition of this material. 

Catching litter is a rewarding task for people (recreation value, safety) and nature (environment, flora, fauna). Litter traps are very diverse, both due to the requirements set and the environment in which they operate. This module will provide insight into the main points of Litter traps. The aim is to encourage ideas to be taken further so that knowledge about Litter traps is increased.

Intro on Litter traps for removing litter
Cleaning can start once litter lands in a stream or river. This video deals with the possibility of capturing litter from the stream itself, using litter traps. The kind of litter trap, its parts with functions, location and problems will be discussed. Examples are included. See the video Intro on litter traps for removing litter 

This video is made in the context of the educational program of the InterReg project LIVES, that you can find at https://litterfreeriversandstreams.eu/education-program/ 

1. Capturing litter, where and how?

How do we get rid of litter in streams, once it entered? This chapter describes where to start. 

Below you find in figure 1 two pictures of a litter trap, both aiming at clearing the river of litter, but different in layout. This chapter is about capturing litter related to the circumstances of the river, flow, embankment and other issues involved.

Figure 1: Two different traps for litter (source: https://stormwatersystems.com)  

Litter can be in suspension as well as floating. Most of the litter floats. This means that for capturing of most litter, the focus can be on the top layer of running water. According to (Simone Lechthaler, 2020) 90% of the macroplastic volume can be found in the top 0,5 m of the water column. 

Figure 2:  [Watercolumn with upper part floating litter; source: Monitoring en ingrepen op zwerfvuil in rivieren (Case De Leie) Eindrapport, K. Van Craenenbroeck, Msc.; ir. M. Faasse; dra. L. Van Cauwenberghe, 2013], photo of floating plastic bag in upper water column.

Heavier floating debris may have a draft of 20 cm. Considering the upper part of the water column is therefore sufficient in determining a technique for capturing floating litter. This will partly depend on the capture method and capture installation used. 

Apart from its position in the water column litter is also being moved by the surrounding waterflow. Because of different layouts of rivers, litter will be moved as well accordingly. Inner and outer bends in rivers result in differences between flow currents.  In an outside bend, the water flows faster, so more waste is taken along and less remains. In the inner bend it flows more slowly, so more waste can be deposited. Water level changes occur often as well making it possible for waste be deposited on the banks.

Figure 3: Inner and outer bends of a river with erosion and deposition

The slope of the river banks also plays an important role: the gentler the slope, the more waste remains. Another factor is the wind. Strong winds can push up the water and create waves. In the Netherlands, the predominant wind direction is west, meaning that most waste can be found on eastern banks. 

An important secondary goal of catching litter from the water column is to gain insight into the amount of litter that is transported by streams and rivers. The diversity of the amount of litter carried along is known globally, and can indeed also be mapped, but especially the amount of material removed is shown.

2. Functions and parts of a litter trap

The principle of the litter trap is quite simple. Strain the water and the litter remains. While the principle is indeed so simple, there are several variables that add to the complexity. Isn’t the current-carrying river bed too narrow and shallow, or too wide? Is the amount of water and therefore the water level always the same and is the flow rate sometimes not too high? Can you also empty the device? These questions call for the analysis of the necessary functions of the litter trap. When the functions are known, the design of the litter trap can be made.
But before continuing try a small exercise with a homemade litter trap.

Small home exercise – a homemade litter trap

Basically, a litter trap is a large sieve in a river or stream to collect litter. In the next paragraph we explain the challenges and aspects that need to be taken into account when you design a litter trap. To get a feeling for these aspects, you are invited to try it out yourself in a small experiment.

Necessary equipment for experiment:

• a small kitchen sieve
• flowing water (either a small stream in your environment or your bath tub or sink where you manually create a flow in the water with your hands)
• some floating objects (like leaves or frozen pies, do not use plastics in the environment for this experiment!)

Experiment:

Place the sieve in one position in the water and try to collect the floating objects by creating flow.

Answer the following questions:

• What made it difficult or easy to collect the floating material?
• Did you also collect items that you were not intended to collect?
• What did you do when your sieve was full?
• What is your idea about improving the catch?

After this experience you will recognize important aspects that are required for litter traps: guiding the floating litter, holding the litter in place and emptying the litter trap. 

In order to capture litter, a litter trap can literally run after the litter, but a more effective starting point is that the litter is swallowed up by a static litter trap located at one location. Of course, this location should be chosen carefully. Several arguments will count for a valid location. Such as reachability (you want to get rid of the catch via infrastructure), efficiency (you rather position the litter trap near a hotspot or where a solid flow is expected), environmental reasons (a lot of fauna disturbed will not be your aim). And should the only aim be to prevent litter entering the ocean, a river mouth should be the most effective. 

But once the location is chosen the focus is on entering all litter into the litter trap. For this to happen it is necessary that a guiding construction is present to ensure that the litter is led to one place where it is collected. 

Figure 4: A guiding construction to collect waste (source: https://www.theoceancleanup.com) 

For the sake of convenience, the function of guiding litter into the litter trap is included here as part of the task of the litter trap itself. Naturally, there may also be several objects located in the water flow that are responsible for the guiding of the litter. Certainly, if there is a narrowing of the watercourse, the guidance of the litter can be realized with relatively simple aids. It goes without saying that the possible presence of passing, fish, boats, kayaks, ships is something to be taken into account.

Holding litter

After litter has been routed to one location, the second important function is to hold or retain the litter. The litter will have to be hold (until the litter trap is emptied. This means that either the volume of the litter trap must be large enough until the next emptying or the litter trap must be emptied on a continuous basis. In either case, the litter, in its variety of material and size, should not be lost. Retaining litter in a current by definition means that there is an obstruction of the watercourse (backwater effect). This obstruction results in water pressure on the litter trap. To prevent damage to the litter trap due to this increasing water pressure, the water must be able to find its way through or around the litter trap. It means that the construction of the litter trap must have a sieving effect. It does introduce a dilemma: the larger the sieve opening, the more (small) litter parts will not be caught. A small sieve opening will result in more water pressure and will not benefit the construction. With this variable it is clear that it directly affects the amount and size of the litter that is caught. Defining the desired size of litter in advance is therefore an important first step that must be taken. Apart from the litter that is aimed to be captured also organical material (leaves, branches) will be part of the catch. Therefor a big enough construction is desired. It will not always be easy to predict the amount of litter (and organic waste) on forehand, therefor a test period will be useful. During the test period the probable amount of waste can be determined. Also, attention must be paid to local biota. It can be wise taking precautions to prevent fish entering (for example with a shallow litter trap.  

For holding litter it is important to understand the ultimate aim for the litter trap at site. Holding litter to prevent it entering a hydroelectric power station with sensible turbines does differ essentially from holding litter to prevent it continuing downstream the river (see figure 5).

Figure 5: Sieve opening 15 mm (bars) at ECI centrale and 40 x40 mm (mesh) in this litter cage (source: http://www.waterradmolens.nl/LimburgM/ECI.htm)

Holding of litter implies as well that the whole litter trap system (guiding, holding, emptying) must be fixed in place. At least if we aim at trapping litter on a fixed spot in a river. To get this fixing point an anchoring system is used. 

The last essential function of the litter trap is to allow the litter to be removed from the device. Only then does the litter trap work as intended. Removing the litter from the litter trap can be done continuously or batchwise. Continuous removal of litter can be done, for example, with a conveyor belt (figure 6).

Figure 6: Mr. Trashweel (Baltimore, USA), a pontoon with conveyor belt, powered by a water wheel (source: https://www.mrtrashwheel.com).

In a batchwise removal of the litter from the litter trap, this can be done by personnel, mechanically, or through a combination of both. Being able to easily remove litter from the litter trap increases efficiency and reduces the risk of damage to the device. Moreover, it will have to be done in a safe manner (for people, machines and the environment). 

How often the litter trap must be emptied is depending on the batch size. The smaller the litter trap holding capacity, the more often it must be emptied. There is no best size for all litter traps, but for several found litter trap initiatives some typical lay-out add up from 3 (1,5 x 2) to 6 (2 x 3) m2. 

Figure 7: Home made litter trap (manual emptying) and Bandalong litter trap (mechanical cage lifting) (source: https://www.stormwatersystems.com)

The process of litter removal is not yet finished by emptying only. The litter has to be taken ashore and carried away to fulfill the process via disposing or recycling (figure 8). It means that for disposal reasons the location for a litter trap must be chosen carefully. A nearby road for trucks to get loaded will be needed.

Figure 8: The process of litter removal

Check your understanding of some litter trap issues by answering the following small quiz.  

Parts of a litter trap

Litter traps can be designed in different shapes and sizes, as long as they fulfill the functions of a litter trap. That is why when designing a litter trap, the parts are linked to the functions they have to perform. We start with the guidance function. The litter is located in the top disc of the water column, as described before. Because of the possibility of water level rising the most convenient way for guiding litter is to use a floating construction for this. It can consist of simple floating beams of hollow material or wood or by floating screens (figure 7). For all these guiding constructions an anchorage is needed to withstand the forces introduced by the river flow.

Figure 9: Guiding construction. Wooden beam, (plastic) dirt screen, bolinea boom screen (source: https://www.bolinabooms.com) . 

In these cases, the driving force for guiding the litter is the flow of the water. In many cases this will suffice, certainly in the cases as shown in figure 9. However, if it concerns a waterway where shipping is present, guidance over the entire width of the watercourse is not applicable. In those cases, it is possible to opt for a division of the guidance in two different places that overlap in the width of the river, through which shipping then navigates (figure 10).

Figure 10: Litter trapping but ships allowing passage

Another form of guidance is to introduce a water movement that directs the litter to one side. The use of air bubbles is a good example of this. This method is currently under research (The Great Bubble Barrier, figure 11) and is used in Amsterdam, among other places, where shipping must be able to pass and where therefore no floating guidance can be used.

Figure 11: Air bubbles used to force litter to one side of the river where it can be collected (source:  https://thegreatbubblebarrier.com). 

Guiding of the litter to one side of the flow is also aided by external factors. For example, the wind can play an important role here. In the Netherlands, a predominantly westerly wind ensures that (apart from other factors) litter drifts past, especially along the eastern banks. Curves of watercourses also make litter being maneuvered to the outside of the current. In many cases, however, it will not be enough to capture there the greatest amount of litter.

When litter is guided, the flow speed of the water and the angle of the guide screen with the direction of flow are of great importance. High flow velocity puts great pressure on the anchoring of the guiding structure, as does also a too great angle with the flow direction. A high water thrust also increases the risk of the guide screen “tipping over”, reducing its effectiveness. Depending on the parts / materials used, an angle must be determined. A first approximation can be found with an angle of 1: 1 (45 degrees with the flow direction).

The “guidance” function will be followed by “holding” the litter. The litter is directed to the part of the litter trap where it is held. However, if the holding capacity is insufficient, an extra pressure will arise on the guidance part, or the emptying capacity must be increased. It shows that the guidance must always be viewed together with the holding.

Retention of the litter must be done if it is not removed immediately. The longer you wait before emptying the amount of retained litter again, the larger the volume of the retention location must be. This volume will therefore depend on the quantity of litter supplied in the relevant watercourse. Often there is some idea of the amount of litter that is being supplied with a particular watercourse. At this point it is important to introduce some flexibility in the design. After all, if the volume is too small, the clearing frequency must be increased, and in many cases this is not desirable. To prevent the construction from failing when the disposal facility becomes overloaded, a spillway construction for the litter can be provided. The disadvantage, of course, is that some of the trapped litter is then lost and still ends up in the environment.

Litter can be retained both inside and outside the current. In the current means that there will be some pushing up effect and forces on the litter trap construction. Outside the current gives the opportunity to integrate easily with a nearby emptying system (figure 12).

Figure 12: Guiding and holding litter in or out the current, the latter giving easy emptying options.

The design of the object in which the litter is held will be dictated by various factors:

• an easy way of emptying, by hand or by machine
• the volume required for holding
• the anchorage possibilities for the floating device

In many cases, a (square) cage is used for this that can be lifted via lifting eyes. The cage is situated with its bottom at a water depth just below the top disc of the water column (approx. 40 cm below the water surface). The bandalong litter trap (see figure 13) is an example of this construction.

Figure 13: Sequence for Bandalong litter trap: capturing, emptying, disposing (source: https://stormwatersystems.com/bandalong-litter-trap )

Another example of a litter trap is the one situated in the River Darwen in Lancashire (UK), which has a fixed location (and anchorage) and is also emptied by a crane through lifting eyes on a frame (figure 14). Emptying management has become a major challenge here. Emptying the litter trap is often viewed by tourists and local residents who are encouraged to do so. It means a very conscious clean up of the entire area around the watercourse.

Figure 14: River Darwen litter trap (UK) (source: http://www.merseybasin.org.uk/archive/assets/228/original/Darwen_Litter_Trap.pdf )

Litter can also be emptied automatically with the help of a conveyor belt. It means that a structure must be installed that anchors and controls the conveyor belt. The advantage is that in principle everything can be done automatically without (many) personnel. The disadvantage will be a high investment for this system. An example can be found in the litter trap emptying system at the Port of Brussels (source: https://youtu.be/XurnSlI58JMsource).

The anchoring system is an important last part of the litter traps indicated before. Although the litter trap will float, it must be held in place. This can be achieved by driving a pile through the river bed (such as the one used in the Lancashire litter trap (figure 14). It means that the litter trap has a fixed location, which may be desirable depending on the circumstances. 

More often, there is a litter trap that must be kept mobile, especially in order to be able to remove the entire system at extremely high water levels and thus preventing it from being dragged along by the river. This can be achieved by either a rope or chain attached to the system and the embankment. The advantage is that the litterholding construction can be maneuvered to one side of the river and thus emptied out relatively easily.

3. Variety in litter traps

Watercourses differ enormously, due to the flow speed, width, depth, shape and material of the embankment and whether or not shipping is present. Requirements may also differ when using litter traps, such as retrievability at high water, whether or not fixed in the watercourse, emptying by machine or not, and of course also available budget for installing and maintaining a litter trap. One single design litter trap is therefore not sufficient for all situations. This chapter intends to give an overview of litter traps.

In this module we have focused on litter that will be captured in rivers and streams. We did describe that the best option is to prevent litter entering these rivers. One of these entering points can be an outlet construction for the emergency overflow of a sewerage system. Once a sewerage system has reached its maximum capacity a discharge overflow will start working. We can think of a construction to prevent litter at this point entering our streams. Although we can name this construction a litter trap too, it is not the kind discussed in this module. However in figure 15 some formats for this type of catching litter are shown.

Figure 15: Systems to trap litter. From left to right: at emergency overflow of a sewerage system (2x) and a “heliscreen”, a large sieve for litter in a sewer pipe (source: https://stormwatersystems.com/stormx-netting-trash-trap ; heliscreen in gemeente Landgraaf https://landgraaf.nieuws.nl/nieuws/55723/landgraaf-heliscreen/).

Many variables do relate to the kind of litter trap that is useful. If the location is a harbor with a wide span and a lot of ships crossing it’s not obvious to make a guiding construction along the width of the waterway. It will be more convenient to have a manned vessel clearing the waterway every now and then. Or a guiding construction in a corner where the flow is heading to with at the end a litter trap construction existing of a cage with emptying possibilities.

Imaginable also is a system that actively searches for litter by moving towards it. It’s more a vessel but can be called a litter trap as well. Therefor in an overview for different types of litter traps a distinction is made between functioning with or without its own energy source.

In order to gain some kind of overview, the field of litter traps is divided into categories that are reasonably obvious. A distinction is made between the following items:

• Is there a possibility for the litter trap for falling dry? If so, the litter trap will not flow anymore and can be damaged or lose its function.
• Is passing of ships present along the river? If so, no guiding construction can lead across the river towards a litter holding trap.
• The flow velocity of the river. A strong current implies a strong anchorage system and more accurate emptying tideschedule
• The width of the watercourse
• The method of emptying. This can be done by boat, crane or by personell

Last but not least, a distinction is made between the costs that are required for the purchase and use of the litter trap. The global categorization for this in the following overview is low, medium and high.

Based on the above classification, an overview can be made for different types of litter traps. The asked questions in the poster (figure 18) help finding the applicable litter trap.

Apart from the litter traps mentioned in below poster, sometimes new concepts do pop up. One of these is the “waterwokkel”. The concept of the waterwokkel can be imagined by a floating augerlike construction. Propelled by the river flow the wokkel starts turning. River litter will bump to the wokkel while the pitch of the auger blades defines the speed of moving the litter sideways (see figures 16 and 17). The wokkel is still under study.

Figure 16: The wokkel (in study) in action. The floating wokkel is hold by a buoy, anchored to the embankment. 

Figure 17: The wokkel from above, moving river litter to one side where it can be removed.

Answer the following questions to find out that often more solutions are available, but that depending on the circumstances some solutions will fit better than other. Click here for another small exercise!

Figure 18: Poster for different applicable litter traps depending on requirements.

Download here the poster for different applicable litter traps depending on requirements.

Many examples are available in the field of litter traps. Litter traps are often described in a project environment. Various parties (mostly public parties such as municipalities, provinces, central government and water boards) describe the use, operation and results of litter traps in projects. In addition, as previously described, the number of variables surrounding litter traps is very large. For this reason, there is hardly any literature available on the concept of litter trap. This module aims to contribute to this. One exception is (Emma Schmaltz, 2020) a recent study to contribute to Plastic pollution solutions: emerging technologies to prevent and collect marine plastic pollution. 

Finally

Due to the many ways in which litter can be trapped in watercourses, one solution for all situations cannot be provided. What matters is that by disseminating knowledge about litter traps and describing good practices, the effectiveness and efficiency of litter capture is increased. New projects use information that is underlined in this module and that may be useful to be considered in practice. 

The sources mentioned below are mostly applications in projects, products and ideas where inspiration can be obtained.

4. What makes a clean-up (action) effective?

In Module 5 monitoring is discussed. Via monitoring we learn about the effectiveness of clean-up actions. In this paragraph we consider some ingrediënts of clean up actions.

When waste is failed to be extracted from rivers using litter traps, it will most likely end up in larger rivers or the ocean. However, some of it will get trapped on the bottom of a river or end up on the riverbeds. Thus, these riverbeds need to be cleaned. But when can a clean-up action be considered successful?

Introduction video on river bank cleanups for removing litter

Cleaning can start once litter lands in a stream or river. But often litter is deposited on the river banks. This video deals with the ins and outs of capturing litter from these river banks. The actions needed, the way of organizing and which people to connect to for making an effective cleanup action will be discussed.

Watch the video Introduction video on river bank cleanups for removing litter. 

This video is made in the context of the educational program of the InterReg project LIVES, that you can find at https://litterfreeriversandstreams.eu/education-program/ 

The answer to this question might be obvious: when no more litter can be found on the riverbeds. The more difficult question is how this can be achieved. This section will describe how clean-up actions can be organised and coordinated to achieve successful results. Of course, this is applicable to riverbeds that require to be cleaned. When talking about cleaning we imply the restauration of the riverbed’s “natural appearance”. Visible litter should be removed with a focus on large pieces (>1-10 cm). This prevents these pieces from continuing to fall apart and becoming so small that it is impossible to clean manually.

An important first step is the initiative to organise a clean-up. Dependent on the goals of the initiator there are two possibilities for such organisation:

• Somebody/an organisation such as the IVN (Instituut voor Natuureducatie)/ a company wants to organise a clean-up with a group of volunteers. (coordination and facilitation)
• Somebody/an organisation/ a company wants to enable the organisation of a clean-up. (coordination) 

We will discuss the most important activities pointwise. The knowledge about these activities has been developed through years of experience with clean-ups. Trial and error was an often-used method, and best practices will be described below:

Option 1 – Clean-up which is coordinated and facilitated

1. Reach out to municipalities and landowners/management 

A. Ask whether they are willing to participate in the facilitation of materials and services, such as litter picks, plastic bags, gloves, the permission to access terrain and the removal of litter.

B. Based on the local knowledge of municipalities and terrain management, the most suitable cleaning locations can be chosen (safe, accessible, presence of litter, permission to enter). Then make an overview of these locations.

C. When making such an overview, clearly depict the collection site, the area that has to be cleaned, the meeting time and the number of participants. 

D. Important! Both the breeding season (in the Netherlands lawfully so) and the high amount of overgrowth on the riverbeds during the summer months, need to be considered.

2. Find a group of volunteers 

A. Imagine you chose five areas to clean. Then find five volunteers who are willing to coordinate such an area (the same for any other number). 

B. Organise a meeting with these five volunteers in which you explain to them what is expected.

C. A coordinating volunteer makes sure that:
I. A group of participants is recruited and informed;
II. This group of participants is received and welcomed;
III. The materials, such as litter picks, bags and gloves are collected at the concerning municipality or terrain management;
IV. Ensures that the litter is collected in one location and notifies the municipality or terrain management about this and the number of bags gathered. These results are collected, and the municipality or terrain management knows to communicate this to the coordinator of the project. In the case of the Netherlands this is the IVN. 

D.
Tip 1:
In the Netherlands, the department of Waterways and Public Work offers to collect trash from the river floodplains. When a municipality or terrain management isn’t willing to do this, it is helpful to find a similar organisation to the Dutch department to do this.
Tip II:
In the Netherlands we have educated river researchers. Through citizen science, the origin of waste is researched. This is done using the OSPAR method. An explanation about this can be found on www.schonerivieren.nl.
Tip3:
It is also useful to download the Literraty app. This app can be used by everybody and facilitates the documentation of the sources of waste. 

3. Offer a platform where people can sign up for the clean-ups.

A. Choose an already existing platform or create a platform where the different clean-ups can be registered and where volunteers can register. In the Netherlands we for instance use www.maascleanup.nl
B. Design the registration in such a way that the local coordinator of the clean-up receives the contact details of the participants.
C. Further design the application process in a way that the participants will automatically receive an email with the google-maps link with the location, the meeting time and the contact details of the coordinator.
D. Tip I: In the standard email include information about the preparation, such as not to remove liquids from bottles, the obligation to wear gloves and the recommendation to wear sturdy shoes and clothes that cover the body.
E. Tip II: Send the volunteers who coordinated the clean-ups a thank-you present and send them a follow up regarding the results of the clean-ups.

Option 2 – A clean-up which is coordinated only

1. Reach out to municipalities and landowners/management 

A. Ask whether they are willing to participate in the facilitation of materials and services, such as litter picks, plastic bags, gloves, the permission to access terrain and the removal of litter.
B. Based on the local knowledge of municipalities and terrain management, the most suitable cleaning locations can be chosen (safe, accessible, presence of litter, permission to enter). Then make an overview of these locations.
C. When making such overview, clearly depict the collection site, the area that has to be cleaned, the meeting time and the number of participants.
D. Important! Both the breeding season (in the Netherlands lawfully so) and the high amount of overgrowth on the riverbeds during the summer months, need to be considered.

2. Ensure that the municipality or terrain management clearly aligns with local associations who cleans what area on which date and at what time.

A. Make an overview of the clean-up areas together with the municipality or terrain management. Attach a code to each area which the municipality can distribute over the different associations. This ensures that an area isn’t accidentally cleaned by multiple groups.
B. This overview can be shared between the municipality/terrain management and the associations to align who wants to clean what area.
C. The municipality/terrain management facilitates the associations by providing them with litter picks, plastic bags and gloves.
D. The municipality/terrain management facilitates the associations by helping them in the collection and disposal of litter.
      Tip: this can also be done by an organisation which manages waterways, such as the Dutch Rijkswaterstaat.
E. Afterwards the associations receive a reimbursement. In the Netherlands we reserve between 100 and 250 euros per group. A group usually consists of around 20 people, who clean around 2 kilometres of riverbank. However, this is largely dependent on the amount of litter that can be found. On average, a group cleans for 3 hours. If the area isn’t finished, we will organise another clean-up for this area. The associations receive this reimbursement when they deliver the results of the clean-up, such as the number of participants and the number of bags of litter collected.
F. The municipality or terrain management will pass on the following information to the coordinating party: the number of participants and the amount of litter cleaned (number of bags of 60 liters) per association. As coordinator you make an overview of this and ensure everything is reported. You then share the end-result with the outside world to demonstrate the impact.
G. As Coordinator you are responsible for the coordination between the different clean-ups and will ensure that this is communicated clearly between the municipalities.

3. Offer a platform

A. Choose an already existing platform or create a platform where the different clean-ups can be registered, and a clear overview can be found.
B. Clearly display the vulnerable or dangerous nature areas, which are thus forbidden to enter.
C. Furthermore, use this platform to present your results. 

Finally, we encourage you to have a look at the website Schone Rivieren Publiek (rijkswaterstaat.nl).  Here you can find an overview of the different clean-up areas along the Dutch riverbeds. Moreover, you can see our methods and how we inform people. When a clean-up has finished, we also display the results, if possible including some pictures. When people zoom in on their clean-up action, the results of this clean-up action including pictures can be found. 

This is an example of the details we receive of the coordinators and municipalities per clean-up:

• Date clean-up: 23-03-2019
• Number of volunteers: 35
• Number of bags (60 litre): 18
• Estimated weight (kg): 10 kg

References

Click here if you are interested in the references of this module.