Archiwa Knowledge - Ecol-Unicon

Periodic river flooding, whether as a result of prolonged rainfall or spring thaw, is perfectly natural in our geographical area. Unfortunately, in the face of serious climate change, we are increasingly confronted with dangerous torrential rainfall that leads to more serious phenomena such as flooding. We therefore need specific solutions to increase the retention and use of rainwater.

What is flooding?
Climate change and human interference with water management
Flood risk management
Modern flood protection – HYDROZONE retention tanks
HYDROZONE – implementations and benefits

What is flooding?

According to the definition adopted by the Water Law, flooding is to be understood as the temporary covering by water of land that is not normally covered by water, in particular caused by the surge of water in natural watercourses, reservoirs, canals and from the sea, excluding the covering by water of land caused by the surge of water in sewerage systems[1].

In reality, it is one of the most dangerous and violent phenomena, with huge economic, environmental and even human losses.

According to UN data, natural disasters account for more than 90 per cent of all major recorded events, and of these, floods, inundation and waterlogging are responsible for more than 40 per cent of the damages[2]. These dangerous and catastrophic phenomena are the result of severe climate change, but also of an irrational human economy.

On one hand, climate change has resulted in prolonged periods of drought, but also in extreme events such as heavy torrential rainfall. On the other, the development of riverbeds and increasing areas of impermeable surfaces, such as concrete plazas, paved roads or buildings, do not allow rainwater to naturally infiltrate into groundwater. Instead, they run off at a rapid rate causing the water level of rivers or reservoirs to rise rapidly.

Flood risk management

Flood risk obviously cannot be eliminated, but we can manage flood risk. On 23 October 2007. The European Parliament adopted the Floods Directive[3], which requires Member States to take measures to reduce the risk of flooding.

In Poland, protection against flooding is the responsibility of the State Water Management Company Wody Polskie (PGW WP) as well as the central and local government authorities. In accordance with the Floods Directive and the Water Law Act, flood risk management plans as well as hazard maps and flood risk maps are prepared periodically to increase the safety of the Polish population.

It is also necessary to coordinate measures within entire catchments so that those taken in the upper part of the catchment, such as construction of dykes, do not increase flood risk in the lower part.

When planning such activities, it is extremely important to use solutions to increase natural retention and protect environmentally neutral ecosystems. Natural retention will not only allow excess water to be retained in the event of heavy rainfall, but also to be used in periods of prolonged drought.

Modern flood protection – HYDROZONE retention tanks

HYDROZONE systems from Ecol-Unicon are an innovative approach to the retention problem. The distinguishing feature of such solutions is their modular design and the possibility to freely configure equipment elements to meet the needs of rainwater and snowmelt pretreatment, retention and utilisation.

The stored and pretreated rainwater is reused to wash streets, car parks, water green areas or flush toilets. It can also be infiltrated into the ground, significantly reducing the costs associated with lost retention charges. Our range includes water retention systems to suit different needs, such as BASIC, CLEAN and BENEFIT.

HYDROZONE – tangible solutions and benefits

HYDROZONE BASIC tanks were used, among others, during the construction of the Hillwood Łódź Górna logistics centre located in the southern part of the city. The facility consists of a large area of roofs and sealed surfaces, which required an appropriate rainwater collection system. Water entering the retention tank is successively pumped out into the storm sewer system, which provides a backup for the capacity of the entire system.

Two tanks founded in Józefów Street in Łódź have a capacity of 1,500 m³ and a length of almost 70 m. In addition, they are equipped with a pumping station consisting of a chamber and modern water treatment devices.

The HYDROZONE BENEFIT system, on the other hand, has proved its worth in Międzywodzie, a small coastal town. For years, residents there have struggled to cope with the effects of torrential rainfall along the coast and droughts in the northern part of the town.

The system, with a capacity of 115 m³, provides storage for water from rainwater systems and, through the use of additional water treatment modules, allows it to be used for other purposes, such as watering greenery.

*Implementation of the HYDROZONE BENEFIT tank and the BUMERANG SMART system in Międzywodzie*

HYDROZONE BENEFIT was also used in the construction of a floodplain polder in Rawicz. A prefabricated reinforced concrete retention tank with a capacity of 550 m3 was used to temporarily collect rainwater fed by the planned canal at Kadecka Street. It consists of flat closing modules, an extension module, internal supports and covers

The system comprises of an integrated mineral suspended solids and oil derivatives separator and two pumping systems. The solution effectively relieved the pressure on the existing rainwater drainage system and dewatered the surrounding area.

In turn, HYDROZONE BENEFIT modular retention tanks with a capacity of 500 m3 in Gorzów Wielkopolski made it possible to eliminate local flooding in the area of Szarych Szeregów Street, Ogińskiego Street, Prądzyńskiego Street, Sosnkowskiego Street, Jarocki Street and Załuskich Street. They also made it possible to regulate the management of rainwater and snowmelt in the WS-1 catchment area in the Szmaragdowa Street.

The BUMERANG SMART system was used in all systems. This is an innovative solution for monitoring the operation of equipment and facilities in water and wastewater systems, and is an integral component of HYDROZONE tanks. It not only enables better management of rainwater retention and use, but also economical and efficient management of the operation of the entire water and sewage network.

[1] Act of 20 July 2017. Water Law (Article 16(43))
[2] Economic Losses, Poverty & Disasters 1998-2017
[3] Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007

The world is running out of drinking water, so it is important to manage the available resources efficiently. The use of rainwater is becoming increasingly popular, both in households and in urban spaces.

By using rainwater in your household, you can reduce your water consumption by up to half. It is perfect for flushing toilets, cleaning, or watering the garden. On a larger scale, rainwater is used in agriculture, industry or for flushing sewage systems. Most often, retention reservoirs are used to collect precipitation, allowing water to be stored until it is actually needed. We decided to investigate and present interesting solutions for the use of rainwater in countries where the technology of rainwater harvesting has been perfected, reaping both the economic and ecological benefits.

New Orleans (USA)

In this city, a neighbourhood was built on previously drained, rather marshy land. Unfortunately, the site suffered during the famous Hurricane Katrina and was once again flooded. The authorities decided not to deal with the excess water in the area any longer and, after rebuilding the district, relied on the accumulation of rainwater. The Mirabeau Water Garden project was created and is currently being implemented. It will have a surface area of 100,000 square metres and the capacity to store around 35,000 square metres of water. Numerous mini-parks have also been created in this difficult area to collect water from the neighbouring plots.

Copenhagen – Tasigne Plads (Denmark)

Umbrella-shaped installations have been set up in the Copenhagen square to collect rainwater, which is then used to water the urban vegetation. In addition, the area has been deliberately landscaped so that the hollows with trees and flowers accumulate as much rainwater as possible, with any excess going into underground tanks.

Industrial estate in Kingston (Australia)

Three streets were renovated and their surfaces replaced with a permeable layer. New rain collectors were installed and 54 infiltration ditches were created along the roads. Special infrastructure was also created to collect water from roofs and streets, which feeds the underground retention tanks. The filtered rainwater is used to water the urban vegetation and is also pumped to hydrophytic systems where plants take care of its treatment. The Kingston Renewal provides annual storage of approximately 4,000 cubic metres of water.

Warrnambool (Australia)

Here, a comprehensive system was created to collect water from the housing estate’s roofs into an above-ground retention tank. In order to do this, a separate rainwater drainage system was run from each house, which then transports the water to the tank. The collected rainwater undergoes a treatment process in which it is given the quality of drinking water. Thanks to the measures taken in Warrnambool, more than 16 million litres of water are collected annually. This impressive amount is the equivalent of what the local population drinks in a year.

Houtan Park (Shanghai)

It is an example of a comprehensive use of space, not limited to the use of rainwater, but extending its properties to purify the air, filtering water from the surrounding river, protecting against floods and providing a place for leisure and recreation. Houtan Park was developed as part of the 2010 World Expo project on a brownfield site adjacent to the polluted Huangpu River. The park area has been arranged in a terraced and cascading manner, with lush vegetation developing on each floor, which filters river water and rainwater in a completely natural way, purifying and aerating it. The water thus collected is used in the Expo Park below.

Rainwater use in low developed coutries

While there are many examples of rainwater harvesting in rich countries, it is still not popular in low-industrialised countries. One reason for this is the very low rainfall in regions such as Central Asia, India and Africa. A second obstacle is the lack of funds to build retention tanks or implement systems to collect water from the roofs. Therefore, in underdeveloped countries, rainwater is used on a small scale, people collect it for their own use in domestic tanks and use it in everyday activities such as washing, washing and even personal hygiene. The water collected in this way is also used in local agriculture to irrigate fields.

Trees, both in the forest and in the city, play an important role in the hydrological cycle by reducing the risk of flooding. The retention of vegetation is able to effectively support not only soil retention, but also ground retention. This is because diverse vegetation simultaneously absorbs and stores moisture, actively participating in the infiltration process. Furthermore, it is largely responsible for avoiding soil erosion by slowing down surface runoff.

Ecological function of the forest

Rainwater retention – by means of the properties of the forest soil – has a positive effect on runoff. This is due in large part to the topsoil, which is protected by undergrowth, mulch, underbrush and, above all, tree crowns. This allows most of the rainwater to soak into the soil and then drain off very slowly. Thanks to the presence of highly absorbent organic soils, rainwater is still “looked after” for some time by the forest vegetation, especially trees.

Forests are responsible for the natural regulation of water relations, acting over vast areas to reduce the risk of flooding. Thus they have a great influence on agricultural crops and even on the water supply of cities, settlements and industrial facilities.

Natural retention reservoir

Forests, like peat bogs and soil, act as natural retention reservoirs, effectively protecting against floods which can cause huge damage. This is why it is so important to take care of vegetation that is able to collect and retain water. In the event of drought, the forest gives back the stored water, regenerating itself. At the same time, it is in charge of the rivers, guaranteeing biological flow. As a result, it is possible to obtain water for the industrial and agricultural purposes.

Natural retention reservoirs are maintained by the State Forests staff, who additionally choose to enhance retention by reconstructing existing natural retention capacities. This is necessary so that rainwater does not run off too quickly. This applies especially to mountain forests, as their natural retention capacities allow the regulation of water resources in river basins. Deforestation of these areas and consequent soil erosion or soil drought must therefore be prevented.

Look after the urban vegetation!

Apart from the obvious aesthetic reasons, trees have a very practical function – they lower the temperature, create cool, shady places for protection from the sun, and absorb many pollutants such as NO, PM, SO2, O3 and greenhouse gases, including CO2. The leaves of trees act as filters: through a process of gas exchange, they absorb the air together with dust and chemical compounds, and they do so extremely effectively: dust in urban spaces can be reduced by up to 75%! Trees produce vital oxygen and contribute to reducing greenhouse gases.

However, the most important – and most difficult – task is to retain water, increase retention and prevent the soil from drying out. If we do not take care of the drainage system, there is a risk of sewage failure and periodic flooding. In urban conditions, all vegetation has a beneficial effect on retention phenomena. Unfortunately, as a result of accelerated surface run-off and lowered groundwater table, maintaining green areas and parks in the city is becoming increasingly difficult and expensive. If nothing is done, trees dry out and green areas in cities gradually disappear as a result of these phenomena and urbanisation. Trees are cut down and replaced by shopping centres or supermarkets, which, without ensuring retention, is an example of anthropopression, i.e. the negative impact of human activity on the natural environment.

An important element for the maintenance of green areas in cities may be the use of rainwater and snowmelt collected in multi-functional tanks for the alimentation of green areas, implemented in a cyclic “smart way”. The city should become like a sponge – naturally absorbing rainwater the moment it appears and giving it back later for various purposes for the benefit of vegetation and people.

HYDROZONE retention tanks are one of these smart solutions that are ideal for use in tight urban environments thanks to their compact, modular design. The use of pre-treatment systems offers a wide range of possibilities not only for retention, but also for the use of the stored water. This has a significant impact on stopping urban drying out, i.e. reducing surface water run-off in order to protect and restore water resources.

Proflieration of concrete is affecting more and more Polish cities, and replacing green areas with concrete slabs is a common phenomenon. This not only drastically changes the landscape, but is also a real danger to residents – if only because of the constantly rising temperatures. So let’s take a look at a few Polish cities where concretitis is at a particularly high level.

Skierniewice facing the threat of water shortage

Skierniewice is a flagship example of concretitis. In the 1970s it was a city full of greenery, trees and flowers. In 2005-2006, however, the Skierniewice market square underwent a total metamorphosis – it was deprived of vegetation and replaced with “modern” concrete slabs.

*Skierniewice market square devoid of greenery*

The effects of the change have been disastrous. Through overheating of the slabs and the lack of the natural tree cover, the perceived temperature has risen dramatically. Moreover, during summer months the city faces the threat of water shortage. However, Skierniewice authorities have decided to take a step towards improving the situation and restoring green areas. The city will take part in the project “De-concretised”. Based on a survey conducted among residents on what should be changed in the city, green areas, relaxation spots as well as sun and rain shelters will be created in the market square.

Włocławek with the costly removal of greenery

The once green Włocławek was “revitalised” in 2014 in a rather peculiar way. The change consisted mainly of removing green areas and replacing them with large-format concrete slabs. Residents even hailed the market as a “concrete desert”. However, the most controversial was the fact that as much as PLN 6.3 million was paid for getting rid of trees, grass and hedges.

*Changes in the Old Market Square in Włocławek / fot. Sławomir Bieńkowski*

Over time, the authorities of Włocławek have also concluded that there is not enough vegetation in the city. Although an attempt has been made to change this, there will be significantly fewer green areas than before the revitalisation. The amount of money that can be allocated for this purpose is also much lower (about 600 thousand zlotys). Another problem is that the city only owns 5% of all real estate in the city centre, which limits the possibility to carry out major changes.

Krzeszowice hot as a pan

Krzeszowice became infamous recently for an event carried out by 19-year-old Kacper Ropek. Observing the aggravating problem of rising temperatures, he decided to test the heat level in practice. On a sunny day Kacper went to the paved market square in Krzeszowice with a frying pan and eggs. What was the result? Without any additional heat source, using only the heating concrete slabs, he cooked scrambled eggs in 80 minutes.

Kacper’s experiment shows just how great a danger the paved areas can be. Overheating slabs not only cause discomfort, but can also have a negative impact on health. Residents are also aware of the problem and have prepared a petition to restore green areas in public spaces. The problem, however, is the lack of funds for this purpose.

The modern, concrete Poznań

Poznan has also followed the example of many Polish concrete cities. The authorities undertook the renovation of Rynek Łazarski (costing almost 43 million PLN), which consisted in introducing modern blocks and an aesthetic, consistent finish. Unfortunately, the authorities of Poznań forgot about vegetation, replacing almost all trees and bushes with stone and concrete.

According to those in charge of the project, the trees were cut down to make way for new water supply and sewage networks. They also wanted to increase the capacity of the roads and widen the pavements. However, apart from small pots, there was not enough free space for plants.

*The only vegetation present in the Łazarski Square / fot. Piotr Skórnicki, Agencja Gazeta*

And it does not have to be like that at all! One of our projects – the Hydrozone Benefit retention tank along with stormwater drainage in Międzywodzie – shows that the construction of new water facilities does not have to bring negative consequences for green areas. What is more, the adopted infrastructure actually supports the plants – e.g. through the implementation of pre-treatment systems thanks to which water can be successfully reused for watering. The project is supervised by the Bumerang SMART system, which allows for monitoring and management of the entire facility.

Łódź and its rain problems

Large quantities of concrete are also taking their toll in Łódź. A side effect of removing some of the green areas in Łódź is not only an increase in temperatures, but also frequent flooding of the streets. Despite strenuous efforts and modernisation of sewage systems, heavier rainfalls often turn the roads into rivers.

*Dąbrowski Square in Łódź covered in concrete*

However, the Łódź authorities are trying to combat concretitis by introducing more vegetation in public spaces. One of the latest projects is the complete reconstruction of the Wolności Square so that it features more trees, lawn and bushes. The so-called rain gardens and systems for self-sufficient retention will also be created.

The problem of concretitis in the Polish cities is unfortunately still a widespread phenomenon. Apart from the five cities mentioned above, in many other parts of our country we see situations where stone, cobblestone and concrete cover areas much larger than green spaces. It is good that some of the cities are slowly reflecting and are trying to restore vegetation in the urban landscape. However, the path towards green balance is still long and, nomen omen, paved with many problems…

Rainwater and process wastewater may contain oil-derived substances (such as oils, petrol or grease), which pose a serious threat to the environment. However, there is a way to significantly reduce the risk of such problems occurring – the use of oil separators. These are devices that separate mineral suspended solids and oil-derived substances before the water enters the reservoir or sewage system.

Oil separators and how they work

Oil separators, or otherwise known as hydrocarbon separators, are used for treating rainwater and process wastewater. They are used for separating and storing accumulated and separated light liquids with a density no greater than 0.95 g/cm3.

Devices of this type take advantage of difference in density of hydrocarbons in relation to water. Hydrocarbons accumulate on the surface of wastewater, increase their volume and form a suspension which is then filtered out. Depending on the size of the catchment area and the type of facility, sedimentation, flotation or coalescence is used to achieve this purpose.

When choosing a particular model of oil separator, it is worth taking into account not only its features and specifics of operation, but also its suitability for the current needs. Selecting a device which ensures efficient filtration is a guarantee of adequate water treatment.

Coalescence separators – what are they and how do they work?

Coalescence separators are free-standing flow-through or in-soil devices for separating and storing light liquids or oils from wastewater. To increase efficiency, unlike conventional oil/water separators, they are additionally equipped with a coalescing insert.

Separators of this type isolate oil-derived pollutants in the separation part due to the gravitational phenomenon, further assisted by the coalescence phenomenon. As a result of sedimentation, suspension is settled and then filtered.

Larger oil particles float upwards thanks to the floatation phenomenon, and those that have been broken down several times by adsorption are deposited on the surface of the coalescing filter, combined into larger particles, and then float to the surface.

The treated water flows out of the separator through an outlet equipped with a float shut-off, which closes as soon as the accumulated oil substances overflow. This prevents contamination of the sewage system or the natural waters.

Coalescence separators are typically used for treating rainwater and snowmelt originating from roads, motorways, car parks, fuel distribution points, storage depots. They are also used for process water from car washes and garages.

*Coalescence separators are used wherever there are lots of cars*

Lamella separators instead of coalescence separators?

How do lamella separators, frequently used instead of coalescence separators, work? In this type of device, rainwater is directed to the first part of the device, which is an inlet chamber with a deflector. This calms the flow and directs the effluent stream to the filtration chamber.

Separation of pollutants takes place during the flow of contaminated water through the specially constructed lamella sections.

Inserts contained in lamella separators force a multi-stream flow, which results in a reduction of the wastewater flow velocity. Oil-derived substances are then separated using the flotation and sedimentation processes.

The treated wastewater is then directed to an outlet chamber fitted with a lid, which prevents the contents of the separation chamber from overflowing into it when the wastewater is backpressured into the unit.

Oil separators with lamella insert can be used to treat rainwater run-off from industrial areas, municipal catchment areas, roads, car parks, forecourts and other paved areas.

What is the role of settling tanks?

Settling tanks are devices for treating wastewater of easily settling suspended solids with a density greater than 1 kg/dm3, which can provide further assistance for the operation of oil separators.

They work by releasing suspended solids when the flow is slowed down, which is achieved by increasing the surface area per unit of wastewater received.

Depending on the type of catchment area and the required level of wastewater treatment, two types of settling tanks are used: horizontal or vortex ones.

How do horizontal settling tanks work?

Horizontal settling tanks use the phenomenon of sedimentation for retaining suspended particles and solids. The efficiency of the device is additionally increased by the installed deflector.

How do vortex settling tanks work?

Vortex settling tanks are most often installed in urbanised areas, where it is recommended to use devices with high suspended solids removal efficiency and a small footprint.

This type of device uses centrifugal force, which aids the separation of fine suspended particles and improves the efficiency of separation at high hydraulic loads.

Additional support, as in the case of a horizontal settling tank, is provided by a deflector which ensures better distribution of wastewater over the surface of the device and reduces the so-called dead zones. Ecol-Unicon offers both single- and double-chamber devices of this type.

The full range of oil separators and the associated settling tanks can naturally be obtained from Ecol-Unicon!

With the growth of cities and industry, more and more pollutants have started to find their way into Polish waters. What is more, the problem of poor water quality, due to ongoing climate change, will only get worse. The situation is exacerbated by leaking septic tanks, irrational fertilisation, growing tourism and, above all, the lack of a long-term vision for water management in Poland.

Water is the basis for the functioning of Poland’s ecosystems and the country’s entire economy. It is also a source of serious social concern. On one hand we fear prolonged periods of drought and serious water shortages, and on the other we fear violent phenomena such as storms or flooding.

According to the report “Water resources in Poland – protection and utilisation” commissioned by the “Przyjazny Kraj” (Friendly Country) Foundation, it is not the lack of water, or its availability, that is a problem in Poland but mainly its quality[1]. This is because we have at our disposal resources which are typical for our climatic zone, and the existing water shortages are rather of a local or temporary nature

What is the quality of water in Poland?

Water is contaminated when it contains an increased amount of chemicals, bacteria and micro-organisms which are not natural components (and simultaneously have a negative impact on water properties).

According to the report, poor condition of Polish waters concerns 91.5% of river resources, around 88% of lakes and nearly 100% of transitional and coastal surface waters. Waters are polluted primarily with benzo(a)pyrene, as well as with fertilising substances such as nitrogen and phosphorus.

*Most rivers and lakes in Poland are polluted*

Where are the greatest risks?

It turns out that it is no longer cities and industry that pose the biggest problem for Polish waters. The improvement in this area is the result of numerous investments in environmental infrastructure and major legal changes. As a result, over 95% of city dwellers currently benefit from sewage treatment plants.

Unfortunately, the situation is much worse in rural areas. Only just over 44% of rural residents treat their wastewater. It is not only fertilisers that are a problem here, but also leaking domestic septic tanks. In addition, progressive eutrophication, followed by the formation of oxygen deserts in which life is dying, is becoming an extremely serious threat. Agriculture is the sector which most seriously threatens the quality of Polish groundwater and surface waters.

Growing tourism is also a serious problem, affecting the development of coastal and lakeside areas. Holiday homes, recreation centres and private cottages are springing up like mushrooms, resulting in more and more municipal and industrial pollution.

What is eutrophication?

Eutrophication, or ‘water bloom’, refers to overfertilisation of aquatic environments caused by excessive amounts of nitrogen and phosphorus compounds. Dead algae sink to the bottom of the tank and decompose, which is accompanied by increased oxygen consumption. Anaerobic bacteria are formed as a result, and as they decompose they emit pollutants – harmful hydrogen sulphide.

Eutrophication is favoured by the regulation of rivers and the decline in their self-purification capacity. This phenomenon, however, mainly affects the still waters of the Baltic Sea and the Great Mazurian Lakes.

The dead zones constitute about 17% of the seabed area, while nearly 30% are oxygen-deficient zones. More than 50% of sea bathing sites are temporarily closed due to blue-green algae. These problems are exacerbated by increasingly severe climate change leading to rising water temperatures.

The effect of agriculture on the pollution of Polish waters

Agriculture in turn affects both the quantity and quality of water available in Poland. As much as 50% of nutrients flowing into the sea and lakes come from this sector of economy. The most important sources are fertilisers and pesticides as well as animal faeces.

Excessive use of fertilisers by farmers (inadequate for plant needs), as well as fertilisation at inappropriate times, result in the transmission of nitrogen and phosphorus compounds to surface waters.

Simultaneously, as forecasts show, agricultural production will continue to increase in the coming years, as a result of both population growth and increased meat consumption. It is therefore important to take action to protect the aquatic environment from the nitrates and phosphates present in manure and fertilisers.

*Agriculture often has a negative impact on water quality*

Harmful effects of mining

Water relations in Poland are also strongly affected by the mining industry. Lignite opencast mines in Bełchatów, Konin and Turów have created huge depression funnels, which contribute to lowering the water table. As a result, local water shortages and even lake drying up phenomena are becoming more frequent.

How to improve water quality in Poland?

The recommended strategic direction is renaturalization, which may bring significant benefits in terms of quality and quantity. It is the best and at the same time simple and inexpensive way to improve the quality of surface waters in Poland. To a large extent it is implemented through… abandonment of negative activities carried out so far.

Education and investment in the development of infrastructure for the collection of pollutants is also extremely important. Systematic and extended monitoring of water conditions may also be a strong incentive to change social awareness and to take active protective measures.

[1] http://przyjaznykraj.pl/wp-content/uploads/2021/06/Fundacja_Przyjazny_Kraj_Raport_Zasoby-wodne-w-Polsce_29062021.pdf

One of the biggest challenges of the still ongoing pandemic is the rapid identification of mutated, unknown variants of COVID-19. As it turns out, sewage can be helpful in monitoring the spread of the virus! Or rather, the information that can be read from it.

Biological content monitoring

Monitoring wastewater for biological content has been a common practice for many years. However, the coronavirus pandemic has increased the importance of this type of activity. Detailed analyses of wastewater are increasingly being carried out to identify the viruses and pathogens present.

Indeed, microbiologists have discovered that sewage surveillance can be successfully used to detect the presence of coronavirus. This is a way of tracking the development of individual variants of the virus. This also makes it possible to identify completely new outbreaks and discover previously unknown strains.

Currently, in some countries, wastewater monitoring is one of the main sources of information on pandemic progress. Despite the complexity of the VOC analysis process, more and more entities are taking an active part in wastewater testing. This is not surprising. This is because it makes it possible to determine the dynamics of the virus and the effectiveness of the vaccination carried out in particular areas.

Wastewater – a valuable source of information for identification of mutations?

Two distinct approaches are used in the wastewater surveillance process:

The first is based on procedures for sequencing the viral genome and searching for it in the analysed effluents.
The second is based on polymerase chain reaction (PCR) by identifying the presence and amount of coronavirus RNA.

And it is this second method that allows the identification of mutations and their characteristics. Each mutation is assigned a unique code, which allows the information acquired to be organised. A few individual drops of contaminated water are usually enough to acquire variant data. At the same time, the methods used are incredibly effective. It is estimated that by analysing the obtained fragments of the genome, even small mutations can be identified (with a contribution to all infections of less than 1%).

*One drop of water can tell a lot of information!*

Extending findings from tests

Analysis of biological fragments in wastewater provides data that were not possible to obtain with traditional coronavirus testing in patients.

An interesting experiment in this area was conducted in the Netherlands. Researchers compared around 1,000 clinical samples from patients with wastewater samples taken from the same locations.

Testing the contaminated water allowed for obtaining faster and more extensive data. Indeed, it turned out that the effluent sequences reveal mutations that were not recognised when clinical tests were performed. It is even speculated that these mutations may represent completely new, previously unknown variants of viruses – hence the lack of clear identification by traditional tests.

Such knowledge can be used successfully to prevent the spread of new mutations. Indeed, the data obtained from wastewater can provide an indication in the area of the direction of change and the potential risks involved. This is what happened in December 2020, when mutated variants were identified in wastewater. Just a few weeks later, it was these mutations that were seen in new variants of the virus.

Could the future be in wastewater?

Testing wastewater samples can determine the concentration of infected people in an area. Italian scientists even claim that the analysis of contaminated water can be an alternative to rapid screening tests. This is because it enables simultaneous analysis of data from a much larger number of people. And thus, the effectiveness of the carried out measures is higher.

Based on experience to date, Dutch Professor Medema recommends the development of technologies to monitor wastewater content. He sees a need to build a consortium including healthcare institutions, research institutes and water supply companies. Thanks to such cooperation, obtaining information on the course and development of virus transmission will be more efficient than ever.

Water makes up more than 70% of the surface of our planet. Unfortunately, fresh, drinkable water accounts for barely 3%, 70% of which is found in glaciers and snow, mainly in Antarctica. Meanwhile, Poland is one of the European countries with the least fresh water resources per capita. No wonder that the costs of supplying water to households are becoming an increasingly serious burden on local authority budgets and on the budgets of individual Polish families. Can we change this?

Why is water consumption increasing?

Water consumption is constantly increasing, and not just because of population growth. Our hygiene needs and overall consumption are also increasing. Water is needed to produce all the goods we use every day.

Meanwhile, we are buying more and more and getting rid of unwanted items or products faster and faster. Do you realise, for example, that it takes more than 17,000 litres of water to produce 1 kg of chocolate?

Excessive water consumption is also often due to our everyday small negligence within the household, such as a leaky tap, unnecessary running water when brushing teeth or washing dishes, or even an underloaded washing machine.

How to optimise water consumption?

Above all, by saving it and managing it rationally. “Appreciate water!” is the slogan for the last year’s World Water Day, reminding us what a priceless resource it is.

It turns out that we can significantly reduce our water consumption, especially drinking water, which is still being used for watering gardens, washing cars and other household sanitary purposes. How to reduce water costs? Smart retention and responsible rainwater management may be the solution.

Since joining the European Union, Poland has allocated over PLN 60 billion to construction and modernisation of water and sewage infrastructure. This is still not enough, however, and our environmental awareness leaves much to be desired…

Meanwhile, thanks to rainwater we can reduce consumption of tap water by up to a half, and thus significantly lower water costs and reduce the load on the sewage system. From a roof of 100 m2 we can collect up to 60 thousand litres of water per year!

Therefore, it is not surprising that both the Polish government and individual local authorities are increasingly willing to reach for various types of retention solutions and support them financially.

*By collecting rainwater you can save thousands of litres of water a year!*

What do water costs depend on?

Scale matters above all. Where the population density is higher, the price for water and sewage is relatively lower. It is assumed that it makes economic sense to build a sewerage network when there are more than 120 inhabitants per km of network. Therefore, as a rule, charges for water and sewage services are lower in large cities.

Often water and sewerage companies, especially in smaller towns and cities, have no competition, which allows them to exaggerate prices. If, at the same time, they do not try to reduce costs (which the competition forces them to do), prices for water and sewage can be really high there.

The cost of water in a city is also influenced by local geological conditions, financial means of the local authorities or, finally, economic potential of the community.

The last but extremely important element is the existing infrastructure and network efficiency, i.e. the level of expenses related to carrying out current repairs or removing failures. It also includes the often enormous losses of water and penalties associated with environmental pollution.

Who sets water tariffs?

Rates for water and sewage disposal are set by water and sewage companies. Price proposals are then submitted in a tariff application to the State Water Management Company Wody Polskie.

It is it that since 1 January 2018, based on the amendment of the Act of 20 July 2017 Water Law and the Act of 7 June 2001 on collective water supply and collective sewage disposal, it verifies the validity of proposed charges, which is supposed to protect citizens from unjustified price increases. If PGW Wody Polskie considers the water tariffs to be too high, they may reject the application.

Optimising urban water costs

A water and sewage company, like any company operating in the market, should have competition to offer its product at the lowest possible price. This is because it is then motivated to seek savings in production and operations. As a result, it effectively optimises its own costs.

So, how do you optimise water costs? The basis is a well thought-out strategy and consistent implementation of modern and responsible investments or modernisation of existing networks, which will reduce water consumption and improve its efficient use.

Such measures make it possible not only to reduce water consumption costs, but also to improve the quality of wastewater treatment and its processing. They are also necessary to ensure that the network will serve us for many years to come and that the price for the water supplied and sewage discharged will be socially acceptable.

Modern, more efficient and, above all, ecologically safe water and sewage networks based on modular systems of retention tanks, equipped with separators, pumping stations, dry-well pumping stations and other solutions for wastewater treatment or rainwater pre-treatment is certainly a major investment. In the long term, however, it can bring about a really significant reduction in the daily operating costs of such facilities.

What is smart retention about?

Smart retention is not only a modern solution for urban water and sewage networks, but also a way to manage and monitor them. Monitoring systems and remote control of devices installed in sewerage networks are slowly becoming a standard.

They contribute to an increased level of flood protection, enable better management of rainwater retention and use, efficiently manage the operation of the entire network, increase environmental safety, and ultimately significantly reduce costs.

One such system is the Bumerang SMART, which is an integral part of Ecol-Unicon’s range of water protection devices.

This state-of-the-art solution makes it possible to control (via the GSM network) the operation of individual devices in real time. If necessary, it also enables an immediate response to any undesirable events from any location – using mobile devices such as a laptop, tablet or phone.

All data, statuses and device states return to users like a boomerang and are made available to them from a web browser, along with the ability to remotely control individual components.

Thus, smart retention management systems represent the future of water cost optimisation in cities. As these solutions are both environmentally friendly and cost-effective, they are becoming increasingly popular with municipal authorities. An example is the investment in the Budziwój housing estate in Rzeszów.

New technologies are applied in more and more areas of everyday life. However, as Ecol-Unicon’s CCO, Grzegorz Boguś, argued during the 2021 Stormwater Poland conference, implementation of modern solutions in the water management sector is particularly beneficial to both people and the natural environment. We decided to collect the most important conclusions from his presentation!

Water, the most precious resource on earth

When people think of resources, they immediately picture energy, chemicals and minerals. However, a very underestimated resource is water, whose importance for each of us is absolutely indisputable. So it is worth considering what can be done to make the most of its potential.

This is where new technologies come in. With access to devices that monitor flows or precipitation, we are able to adjust the operation of devices used in the water cycle. Combine this with the ability to report any emergent failures or malfunctions and you have a comprehensive approach to managing the water ecosystem.

*Water is the earth’s most precious and often underestimated resource*

How to do smart water management in urban areas?

Swiss scientist Robert Horbaty once created a definition of a truly smart city. It is a place that offers its inhabitants the maximum quality of life while using the minimum amount of resources – thanks to the right combination of infrastructural systems. So it is not only important to manage resources efficiently. It is essential to maintain balance and minimum impact on the environment.

How to manage rainwater?

One of the biggest challenges is rainwater management. In the process of sustainable yet efficient retention management 6 steps can be identified:

Knowledge of how much rainfall occurs in a given city, for which we can use e.g. the PANDa system precipitation model,
Water management including information on how water falls and runs off,
Taking stock of the capacity of retention facilities and reacting quickly to changes,
Forecasting the weather and upcoming precipitation,
Collection of precipitation data by means of rain gauges,
Smart rainwater management using ICT systems, e.g. Bumerang SMART.

Bumerang SMART at the pinnacle of smart retention

Creating a pyramid of smart rainwater retention, at the base we can find all the objects that accumulate rain. Higher up are the devices that allow measurements (for example, rain gauges and probes) and the software that collects data, analyses changes and predicts what will happen in the near future.

At the top are the devices and systems that allow for the comprehensive management of facilities from the base of the smart retention pyramid using data collected and analysed at the middle levels of the entire ecosystem. Bumerang SMART is one such a solution

Bumerang SMART in practice

Practical application of the described capabilities of the Bumerang SMART system can already be observed in several Polish cities. For example, in 2020 it was introduced in Rzeszów, allowing for smart, automatic retention management. System operation is based on real-time weather forecasts downloaded for a given area. In the case of predicted increased precipitation, the system activates an active mode.

From the onset of rainfall, the water collection process is initiated. It remains active until the storage tanks are filled to their maximum capacity and the excess is discharged into the sewer by automatically opening the discharge valves. The most important thing, however, is that the water accumulated in the tanks can be used at a later time, for example, during a dry period. Dedicated barrel trucks collect the water and distribute it, for example, when watering urban vegetation or washing the streets.

As water is stored in the retention tanks, it is constantly being monitored to ensure that the quality is maintained and emerging contaminants are eliminated. If poor quality is detected, the collected rainwater is drained from the tanks. The system also detects impurities entering the tanks during rainfall. In particular, the system closely monitors the level of oil-derived substances in the water.

Similar solutions are also being implemented in other cities. For example, in Starogard Gdański, the Bumerang SMART system was applied to on an open retention reservoir, together with the necessary sensors for managing, forecasting and monitoring water quality. Another project is being implemented in Chojnice, where an smart management system for an open retention reservoir is also being developed.