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Category: Ecology

Poland Surface Waters: Navigating the Ecological Challenges

The ecological state of surface waters in Poland, as reported by the Main Inspectorate of Environmental Protection in 2022, does not inspire optimism. Over 94% of waters (examined as “individual parts of surface waters”) failed to achieve the good ecological status required by the Water Framework Directive. When it comes to chemical status, a mere 12% showed a “good state”. It’s crucial to note that in such studies, exceeding the concentration of even one required indicator determines the classification. Nonetheless, the data presented paints a grim picture of water quality in Poland. This is especially significant in the era of advancing climate change.

The report in question reveals a rise in the average temperature in our country by as much as 1.5°C when comparing 30-year periods, namely 1951-1980 vs. 1991-2020. It’s worth mentioning that the average temperature in 2022 was 1°C higher than the last 30-year period mentioned. Such a significant increase in average temperatures should sound alarm bells, as the frequency of extreme events will only escalate with ongoing climate change. Our commitment to adaptive and mitigative actions against climate change can be implemented across various sectors, with a particular emphasis on energy. However, in this article, I’d like to focus on rivers, which serve as the “cardiovascular network of a living ecosystem” that is our natural environment.

A River is Not a Highway

In cases of prolonged heatwaves, which result in both reduced flow and increased water temperature, the biological life of rivers becomes extremely endangered. Last year’s disaster on the Oder River serves as a case in point: according to government institutions, pollutant discharges were in compliance with issued water-legal permits, yet the catastrophe still occurred. So, what can be done to counter such threats? The government and its subordinate state administrative units are attempting to save rivers through LEGISLATION.

To this end, the so-called “Specustawa Odrzańska” (Oder Special Act) has been submitted to the parliament. It’s a unique occurrence in Europe for lawmakers to dictate what should be built, modernized, and renaturalized at specific kilometers along the river, instead of establishing universal principles for the protection of the Oder. While there are positive provisions, such as increased river monitoring, higher fines for illegal sewage discharges, sealing off illegal discharges, and promoting dispersed retention, they are woefully insufficient. Many crucial aspects of biodiversity protection are overlooked, with the focus mainly on hydraulic structures.

Reading the act, one gets the impression that the primary objective, under the guise of river protection, is to enhance its transport capabilities. Many proposed investments diminish the Oder’s resilience to climate change and localized pollutant discharges—especially saline waters—leading to the death of the river as a natural entity. A significant “sin” of the mentioned act is the manner of its preparation, specifically the near absence of dialogue with the public, including non-governmental organizations. After all, a river is not a water highway generating transport profits but a biologically vibrant environment that constitutes a societies collective good.

You pollute – you pay

Contrary to the newly drafted Water Directive (RDW), the special act still allows for permissible amounts of discharges for stormwater overflows. It doesn’t matter whether we discharge 100 times at 1 m³ of sewage—which won’t negatively impact the river’s self-cleaning abilities—or a one-time 1000 m³. It’s the latter that could jeopardize the river’s biological life. The draft legislation contains many troubling provisions, including those related to specific hydraulic investments. There’s a lack of assessment on the impact of these investments on the receiving body of water. There’s also no attempt to study the river’s resilience to sudden discharges and loads of sewage—this raises my strong objection. I wonder if the authors of the act don’t see the difference between sipping one glass of liquor daily for a specific period and downing several liters in one day? The impact of a large amount of alcohol won’t be beneficial for our bodies, phrasing it lightly. Perhaps this is too stark of a comparison, but like alcohol for the body, sewage for surface waters, when administered in large quantities in a short time, can lead to irreversible consequences.

If, after the Oder disaster, the institutions responsible for the cleanliness of our waters want to bring them to a good ecological state, I suggest starting a broad public debate. A substantive debate will allow for the exchange of knowledge and the preparation of solutions that take into account the needs of society, living nature, and the inland economy. An extremely important aspect of actions for the cleanliness of our waters is respecting the principle: the polluter pays, and the one who manages water and sewage benefits. Unfortunately, I only find the first part of this principle in the described draft legislation. Implementing the whole requires respecting the following values: responsibility, knowledge, passion, and perseverance.

Values to guide us

The first of these values — responsibility — is unfortunately often passed around like a hot potato between various administrative units. Let me give you an example of the wall-like obstacles experienced by employees of a company participating in the “Clean River” project on the Motława River. They approached the local municipality through which the final stretch of the river flows, and the municipality, in turn, contacted Polish Waters to secure a container for collected trash. Regrettably, neither the municipality nor Polish Waters supported the initiative, citing either a lack of competence or the need to adhere to financial discipline. Hopefully, after the next elections, there will be fewer such officials or local leaders. It’s the decisions of such individuals and their failure to take appropriate actions that result in the water transparency in the Motława River, located just a few kilometers away in the historic center of Gdańsk, not exceeding 30 cm. For comparison, the average transparency of Baltic Sea waters is around 500 cm. The trash collected during the campaign—mostly discarded by tourists and local residents—was disposed of at the company’s expense. SCANDAL or “business as usual”? Or perhaps the officials are guided by the idea of not touching certain matters. Why should the water in the Motława be clean? What if it turns out that the sediments contain a whole “Periodic Table” of pollutants? By flowing through rivers, most illegal outlets and unregulated runoff from fields can be detected. In the case of our main rivers, the Vistula and the Oder, the primary sources of pollution are saline water discharges from mining areas, diffuse pollution from agricultural lands, and inadequately treated industrial or municipal sewage. All these pollutants eventually end up in the Baltic Sea, which, as we know, is also an endangered body of water. Due to the lack of continuous water exchange with the North Sea and low salinity, the Baltic has limited self-cleaning capabilities. This is evidenced by frequent cyanobacterial blooms (at the time of writing this article, most of the Tri-City beaches were closed) and the recent burst of the Nord Stream 1 pipeline, which contaminated significant amounts of water with pollutants deposited in the seabed. Despite this, mainly due to rational sewage management in coastal areas, the cleanliness of the Baltic waters is gradually improving. This shows how important responsible water management is in the catchment areas of rivers that feed our sea, and for such good stewards, big applause is due.

The second value — knowledge — determines the scope and possibilities for implementing best practices in water management. The level of expertise in wastewater treatment technology, retention and management of rainwater, sediment management, and intelligent watershed management is continually increasing. Numerous opportunities exist for knowledge exchange in the water environment: specialized conferences, seminars, and webinars are organized both domestically and internationally. Higher education institutions are initiating courses in water engineering and even studies in climate change mitigation and adaptation. One such initiative is the Inter-University Climate Academy (MAK), where students gain knowledge from the best experts and practitioners. I deeply hope that education at all levels will play a significant role in mitigating the climate crisis and restoring clean water in Polish rivers. Leveraging access to the best knowledge, a Gdańsk-based company has developed a concept for an intelligent stormwater overflow chamber. The primary goal of the project is watershed management, which involves managing the flow of rainwater and sewage within designated catchment areas. The project includes the development of a hydrodynamic model with a water demand analysis, spatial planning of the catchment, precipitation sizes and intensities, and determining the load and quantity of sewage and their impact on the receiving body, such as a river or lake. The program promotes large-scale, dispersed retention and cleaning technologies based on natural methods (NBS).

Values like passion and perseverance belong to the social domain. Non-governmental organizations, foundations, businesses, and ultimately, the civic society, hold the authorities accountable to ensure that when creating laws and fighting for clean water, the voice of the community is heard. Perhaps it’s worth reaching for broader technical, environmental, and legal arguments to meet the European Union’s requirements for clean rivers? With the common good in mind, I believe that substantive discussions involving all stakeholders will yield positive results.

Legal Entity Status for the Vistula River

Is solving the problem of river pollution simple? Trendy terms exist, like SUSTAINABLE DEVELOPMENT and DATA MANAGEMENT. To manage something [in this case, bodies of water – water management ], you need reliable data. This data should be publicly available and continuously updated. I advocate for the centralized collection of data on the quantities and loads of discharged sewage. An essential aspect of such a database should be its accessibility to every citizen. There are already cities in the world where anyone can see when and how much was discharged into the river, what load of pollutants was released, and what impact it had on its biological balance. These cities include Yorkshire [United Kingdom], Hamilton [Canada], and Washington [USA].

Beyond data transparency, some countries are introducing legal entity status for rivers, especially those important to a particular region. A river with a legal persona can more effectively defend itself against excessive exploitation or predatory management. Anyone who contaminates it must face the consequences. In Canada, granting legal entity status to the Magpie River has preserved its wild character and protected the heritage of the indigenous tribe inhabiting its watershed. Other rivers with legal entity status include the Whanganui in New Zealand and the Klamath in the United States. Ecological institutions have also taken steps to grant legal entity status to the Colorado River.

Perhaps our Vistula deserves this as well? After all, it is one of the wildest and largest rivers in Europe. Or maybe, to protect its rights, we should establish an Ombudsman for our largest and most polluted rivers, such as the Vistula and Oder? We will ask these questions during this year’s Stormwater Poland conference in Katowice on September 28. I am curious about the public opinion on this matter. We will invite the best specialists from Poland and abroad to the discussion. These will include engineers, hydro technicians, and ecologists. Perhaps a substantive debate will bring us closer to providing special protection for our water heritage?

Doesn’t the ‘wild’ and clean Vistula — our national treasure — deserve special protection? It may turn out that, for the broadly understood common good, the Vistula will better fulfill its role by supporting the inland economy. We will soon know opinions on these interesting issues. To better prepare for the September debate, I invite you to an open discussion on our blog today: www.biznesdlaklimatu.pl.

Wojciech Falkowski

Protecting residents from sanitary hazards – HST solutions for combined sewers

The combined sewerage system discharges domestic sewage and rainwater through a common channel. Therefore, in the event of overflows, e.g. during heavy rains, there is a serious risk of exceeding the capacity of the treatment plant and discharging untreated wastewater to the receiving water body. Sludge removal systems and HST flow control devices can provide a solution to such problems.

  • Sanitation risks posed by wastewater decay
  • Technology to prevent wastewater decay
  • HST equipment and comprehensive support from Ecol-Unicon
  • AWS Jet Cleaner aeration and flushing nozzle
  • AWS Flush Gate

Sanitary wastewater decay is a serious sanitary risk

Sewage decay and the accompanying noxious odours are caused by oxygen deficiency in extensive sewer systems and long delivery pipelines. This occurs after the wastewater has been in the pipeline for only a few hours, and its consequences can be hazardous to the health and lives of both residents and maintenance crews. At the same time, treatment of such wastewater becomes less efficient and more energy-intensive.

Insufficient aeration of wastewater results in wastewater decay. It leads to the oxidation of hydrogen sulphide and the formation of sulphuric acid, which is harmful to the wastewater network components.

Hydrogen sulphide causes corrosion of concrete and metal structures and equipment. It also contributes to the foaming of wastewater and the growth of filamentous bacteria and aerobic chemotrophic sulphur bacteria. It is the gas that causes the most poisoning and deaths among workers associated with the operation of water and wastewater systems. It is particularly dangerous because it cannot be smelled in high concentrations.

Technologies to prevent decay of wastewater

Contrary to expectations, the investment and operating expenses of solutions aimed at preventing wastewater from decay are not high and should already be foreseen at the design stage of the sewage system. They make it possible not only to operate the wastewater treatment plant more efficiently, but also to seriously reduce operating costs.

The most common systems used are aeration of wastewater or disposal with air or water, such as:

  • pipeline blowing with compressed air
  • aeration of wastewater with compressed air
  • water flushing

Another solution used is the application of chemical agents that bind hydrogen sulphide compounds or inhibit bacterial growth. However, this method generates higher costs and increases the risk of corrosion of concrete or metals. It also requires appropriate dosing pumps and equipment to measure the concentration of hydrogen sulphide. In addition, chemical compounds such as nitrates or iron salts are not completely removed during wastewater treatment and may end up in the environment.

HST devices and comprehensive support from Ecol-Unicon

German-made solutions from HST Systemtechnik, such as sludge removal systems, keep sewer networks in optimum condition. These are innovative and effective products that integrate information technology into the operation and management of facilities.

The exclusive distributor of HST products in Poland is Ecol-Unicon, a company that, together with its German partner, provides comprehensive services from the design itself, through the implementation stage, to service.  Ecol-Unicon offers full support in planning, consultancy, assessment, dimensioning or planning documentation of the entire water and sewage system.

AWS Jet Cleaner aeration and flushing nozzle

The AWS Jet Cleaner aeration and flushing jet is a powerful and highly efficient pump with nozzle set. It can be used in combined sewers, wastewater treatment plants, storage tanks and in process water treatment.

The AWS Jet Cleaner produces a water-air mixture as a driving and cleaning jet. This effectively eliminates wastewater decay processes during prolonged retention.

It is a fully automatic cleaning unit which, in its standard version, consists of a pump unit and a set of injectors. The AWS rotary nozzle is equipped with a set of injectors, which allow a large flushing radius even with very different tank geometries. The contaminants are discharged here as the tank is emptied. During the emptying process, the nozzle operates in intermittent or continuous mode, according to predetermined switching points. In addition, cleaning is assisted by rotating movements.

The HydroMatic software used in the streamer allows for energy-efficient control of the entire process with real-time monitoring of the results. It is also possible to individually adapt the operating mode of the unit to local conditions.

Flushing efficiency data is continuously recorded by a screen located at the bottom of the tank. This makes it easy to monitor the effectiveness of ongoing activity. The location and intensity of sludge can be determined by entering the data manually into the control panel or automatically using an optical camera.

AWS Flush Gate

AWS Flush Gate is an extremely effective and fully automatic system used to remove sludge from combined sewers and holding tanks. It works by using sensors mounted in the tanks and relies on the use of stored water to flush the bottom of the tank. Opening the manhole creates a strong wave that safely flushes out accumulated sludge.

A chamber closed by a flap is placed above the section that requires flushing. This allows the chamber to be opened automatically when it is required to remove the sludge from the system. For the remaining time, water is stored in the chamber, ensuring that the sewer can be cleaned even in dry weather.

Thanks to its lightweight housing and compression system, the AWS Flush Gate does not require additional delayed closing mechanisms, minimises hydraulic losses and allows the tank to be completely emptied.

You can find more about the equipment supporting HST’s combined sewer solutions on our website. We also invite you to sign up to our newsletter to keep up to date with all the latest news from the wastewater industry.

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

According to the Intergovernmental Panel on Climate Change (IPCC), climate change is one of the most serious, if not the most serious, challenge to civilisation that we will face in the 21st century. Therefore, the most important step is to understand the mechanisms of the phenomena taking place and to find and apply solutions that will counteract the catastrophic hydrological effects.

  • Hydrological drought in Poland
  • Hydrological warnings from the Institute of Meteorology and Water Management
  • Heavy rainfall and flooding
  • The solution – retention and green infrastructure
  • HYDROZONE retention tanks

Cities occupy a relatively small area on a national scale or even on the scale of the entire Earth’s surface. However, they generate 75% of global GDP, 70% of greenhouse gases, 70% of waste and absorb 60% of energy production. Thus, they have a key impact on climate change and the resulting unfavourable hydrological situation and decline in plant biodiversity.

Most commonly, we can distinguish between three basic challenges involving water:

  • there is too little of it
  • there is too much of it
  • it is too polluted

While the average water supply per capita in Europe is 4 500 m3, in Poland the figure is only 1 600 m3, and in times of drought as little as 1 000 m3. Why such a colossal difference? The situation is largely blamed on much lower rainfall than in western Europe, but also on rapid run-off and the poor retention of the geological substrate.

It is also the result of years of poor water management decisions. Land reclamation, the draining of wetlands, the concreting of riverbeds, species changes in forests, the decreasing amount of mid-field afforestation and the paving of urban areas have all had a disastrous effect on natural retention.

Warmer winters and a lack of snowfall are also an effect of climate change. Meanwhile, it is the spring snowmelt that improves soil moisture and consequently surface and groundwater levels. According to experts, if we do not take decisive action, in 10 years’ time we will have 40% less usable water than today.

Ongoing several years of hydrological drought in Poland

Drought is a condition that is defined in different ways depending on the climate zone and region. In Poland, the accepted definition is 20 days without rainfall, in which case we speak of atmospheric drought. When plants start to lack water, we are dealing with soil drought, and when the level of surface and underground water decreases, the result is hydrogeological drought. The consequences of the latter can be really serious.

In the meantime, we have been experiencing a permanent drought in Poland for about seven years now, and it covers an increasingly large area of the country every year. The country’s hydrological situation is very difficult, and water deficits are so serious that they result in soil and agricultural drought. This is a huge problem, which will not go unchallenged in terms of the amount and quality of crop yields, and thus the already high prices of food.

Vistula from Wyszogród bridge at the lowest water level on record

Latest IMGW hydrological drought warnings

Hydrological drought warnings are issued when, for a minimum of 10 days, values at representative water gauge stations are below the multi-annual average of the lowest annual flows (SNQ).

Water levels in rivers in Poland at the end of May 2022 were mostly at low or medium levels. The most serious problem is observed in Wielkopolska in the Warta river basin, where there has been a marked decrease in river water levels, below multi-year averages.

Warnings were also issued for the Małopolskie, Zachodniopomorskie, Lubuskie, Dolnośląskie, Śląskie, Łódzkie and Opolskie Voivodeships. Despite the recent rains, low water flows are still below the SNQ.

In contrast, torrential rains and floods

Another major challenge, especially in urban areas, is the heavy rainfall that follows long periods of drought. This increased rainfall is caused, among others, by increased temperatures in urban areas (heat islands), leading to a heat exchange phenomenon known as convection.

In cities, there are fewer and fewer green spaces and places where water can freely drain into the ground. Often, surface development and road infrastructure is also a problem, with almost the entire volume of precipitation draining into storm drains and surface waters. If the sewer system is not efficient enough or not fully operational, inundations, localised flooding and even floods can occur, which destabilise the functioning of the city and the lives of the inhabitants, but also generate serious economic impacts and financial losses.

Changing mindsets, or let’s start with ourselves

First of all, we need to completely change our attitude to water. We still think that water is something that was, is and always will be. All we have to do is turn on the tap. However, drinking water is an increasingly scarce commodity and needs to be saved. Yet we are still, more or less consciously, wasting huge amounts.

Did you know that during a 3-minute tooth-brushing session with the tap turned on, we waste about 15 litres of water? In an average Polish household, more than 90% of all water is used for household activities such as washing, cleaning, laundry, dishes and flushing the toilet! Drinking and cooking water accounts for only 3%.

Another serious and yet not very controllable problem is the irrigation of fields and the watering of green areas. If certain requirements are met, the construction of groundwater intakes does not require a special water permit. Therefore, farmers, in order to save their crops, create irrigation systems and drill deep wells. The groundwater used for this is irretrievably lost, whereas it should only serve as a source of drinking water. Even when watering our lawns, gardens or flowerbeds, we use drinkable water from the municipal water supply.

The solution – retention and green infrastructure

Retention is the real challenge. In Poland, it stands at 6.5%, while in Spain, for example, it is as high as 40%.

Large-scale implementation of small-scale retention solutions, blue and blue-green infrastructure in agricultural areas and cities is essential. We need specific solutions for delaying runoff, retaining water and reducing evaporation losses. These should be provided by comprehensive government and local government programmes, but also by our own initiatives and actions.

The development of blue-green infrastructure is the future of cities and municipalities in adapting to climate change. Green and blue areas are one of the most important tools for the prevention of flooding, heat waves and also a greater chance for the ever so important plant biodiversity. The construction of green roofs, green walls or the creation of new plantings, combined with water management solutions, increase water retention and the chance to reuse water.

HYDROZONE smart retention tanks

HYDROZONE is an advanced range of modular tanks for the retention of rainwater and snowmelt. By using supplementary components and equipment, it is additionally possible to pretreat and reuse the medium. The configuration options of the equipment elements can be individually adapted to the needs of rainwater treatment and collection.

On one hand, they allow us to avoid the effects of drought and, on the other, they prevent flooding and inundation in situations of heavy rainfall.  An example of this is the implementation of the Hydrozone Benefit tank together with the construction of a storm water drainage system in the town of Międzywodzie.

A HYDROZONE BENEFIT tank with additional functional modules was used, allowing rainwater to be used for watering the green areas. The BUMERANG SMART system, an innovative tool for monitoring the operation of water and wastewater system equipment and facilities, was also implemented.

The solution has eliminated the problem of flooding during the rainy season and facilitated the drainage of rainwater and snowmelt. In addition, during the non-rainy season in the northern part of the city, the water collected in the tank is used to water the green areas.

Pumping of rainwater and sewage involves pumping a specific quantity of the aforementioned raw medium to a specific height and distance in a given unit of time. What distinguishes dry-well pumping stations from traditional pumping systems is the use of the so-called dry pumps, which are placed outside the retention module filled with sewage or rainwater, so that not only they are safer and more hygienic, but also incomparably more comfortable to operate. Simply speaking, during service operations contact of workers with toxic substances, effluents and sludge of various kinds is reduced to a minimum.

Advantages of using a dry-well pumping station

The advantages of using a dry-well pumping station are numerous. Not only is it possible to service only the selected inflow and outflow circuit while the entire unit is in operation, but access to each of the components is greatly facilitated. Thanks to the solid separation system in front of the pumps, that are not directly immersed in wastewater, we reduce the risk of failure and also make it easier to maintain the cleanliness of the unit, which decisively affects the comfort of servicing, as well as the operation itself by eliminating odours. It is precisely thanks to the removal of unpleasant odours that the dry-well pumping stations can be easily located near residential buildings, inside the buildings and in their surroundings.

The ETS PE model by Ecol-Unicon is a good  example of a dry-well pumping station. ETS PE is equipped with two single-channel solids separators, which are located directly at the discharge connections of the pumps operating alternately, in the external part of the retention module. This solution allows for efficient servicing of the unit and all its modules. This model significantly stands out in the market through the innovative construction of the HDPE chamber. The retention module is integrated into the chamber, thus providing a compact unit. In addition, the pump, as well as additional installations, such as a ladder, an operating platform or a flushing installation, are selected on the basis of project specifications and individual user requirements, which facilitates a comprehensive adjustment of the unit to the needs of the user.

Presentation of the dry-well pumping station ETS PE 80 at the Wod-Kan trade fair in Bydgoszcz

Fading popularity of traditional pumping stations

At first glance, traditional pumping stations seem to be a more popular solution than the above-mentioned dry-well pumping stations. All because of their universality, as well as simplicity of construction, which is usually limited to a tank and submersible pump, resulting in relatively low investment cost. And, although at the design stage we often care about reducing costs, it is worth considering whether the subsequent servicing of such a device will not generate additional budget costs.

Engineers highlight cumbersome operation as the biggest drawback of traditional pumping stations. As previously mentioned, traditional pumping stations, the so-called wet ones, assume the foundation of the pumping system directly in sewage or rainwater. It is because of this fact that maintenance of this type of technology is connected with close contact of sewage workers with wastewater.

It is also worth mentioning that due to the direct contact of waste with the pumping system, such a system is considered to be more prone to failure and has a shortened service life. Traditional pumping stations do not have systems to separate solids from wastewater, so they are easier to fail. Of course, there are solutions in the form of installing screens to retain sand or stones, but these only represent additional costs.

Is this the end of traditional pumping stations?

The growing installation market forces contractors, but also investors, to adapt to its pace, so it is not surprising that dry-well pumping stations are an increasingly popular solution. Their numerous advantages compensate for the disadvantages of pumping stations, which are considered to be the most troublesome. At the moment, it is the dry-well pumping stations that guarantee better comfort of use, lower energy consumption and trouble-free service, but it is not said that traditional pumping stations are a technology to be abandoned. It is worth remembering that the choice between these variants depends on many factors, starting with the location or the amount of sewage we need to pump, and ending with the available budget, including both the installation of the system itself and its subsequent operation. However, it is hard to resist the conclusion that it is the dry-well pumping stations that will surpass wet-well pumping stations in the popularity contest, and for good reason.

The choice of wastewater treatment method is a complex process that depends on several factors. The applied solution should be friendly – both for the environment and the users. Discover the innovative BIOFIT technology and find out why it is the right choice.  

Types of wastewater treatment plants

The importance of wastewater treatment is one of the most significant, and at the same time most often overlooked, aspects of environmental planning. Wastewater poses a threat not only to the environment but also to people. Pollutants can contribute to the deterioration of surface water and groundwater and are a source of unpleasant odours and toxic substances.

The task of the treatment plant is to decompose the collected pollutants into mineral compounds – in this form they will not pose a threat to the environment.

The two most common types of domestic treatment plants can be divided into:

  • drainage treatment plants
  • biological treatment plants

How does each of these solutions work?

Biological or drainage treatment plant – which one to choose?

Drainage plants are based on the two-stage wastewater treatment method. Treatment takes place in the settling tank of the wastewater treatment plant, and in the medium in which the drain distributes the wastewater – this may be soil, sand and gravel filter or reed bed. The water treated in this way poses no threat to the environment, but cannot be reused.

Biological treatment plants, on the other hand, are a more recent method of wastewater management. Its main advantage is a higher degree of treatment than the drainage method. The system is based on mechanical and biological treatment. The biomass used in the process can be in the form of activated sludge or a biological bed.

Construction of treatment plant, retention tank and pumping station for S3 expressway MOP Polkowice

BIOFIT wastewater treatment plant – construction

One of the types of treatment plants offering biological treatment is the BIOFIT system. The device has been designed in compliance with the ATV-A135-P standard relating to the dimensioning of sprinklered and submerged sumps.

The BIOFIT treatment plant consists of four basic components:

  • preliminary settling tank
  • submerged fixed-bed bioreactor
  • clarifying chamber
  • installation chamber

All components of the treatment plant are made of high grade C35/45 concrete and additional materials. Apart from the basic elements of the tank, the set includes also blowers of the aeration system together with a control cabinet.

How does the BIOFIT the treatment process work?

How is wastewater treated using BIOFIT technology? An aerated biological bed populated with micro-organisms is used to break down pollutants.

The wastewater first enters the preliminary settling chamber, where pollutants not dissolved in water are separated.

The treated wastewater is transported to the bioreactor. There is a submerged biological bed inside. The biomass growing in the bed uses the substances dissolved in the sewage as food. Air is pumped into the bioreactor with the aid of diffusers, which guarantees the optimal course of microbiological processes.

The next stage is the clarifying chamber. Here the excess sludge is removed from the treated wastewater. All the sludge is pumped from the secondary settling tank into the primary tank. In this way, it is sufficient to remove it from a single settling tank.

The treated effluent from the secondary settling tank goes to the receiving tank. Thanks to the use of blowers and air lift pumps, the moving and mechanical parts of the treatment plant are not in direct contact with the pollutants. The installation well remains dry and has no contact with wastewater.

Why choose a BIOFIT wastewater treatment plant?

What are the advantages of biological wastewater treatment with BIOFIT? The system itself features a modular design, which makes it easy to adapt the treatment plant to the conditions offered by the environment. The devices can support, among others, residents of small towns, housing estates or buildings remote from the sanitary infrastructure. The plant can also be used for service and road facilities (e.g. petrol stations, traveller service areas). Thanks to the use of prefabricated elements, the BIOFIT WWTP can be built and commissioned within a short period of time from ordering.

Another advantage is the ease of operation and maintenance of the plant components. Thanks to the use of blowers and air lift pumps, the moving and mechanical parts of the treatment plant are not in direct contact with the pollutants. This solution makes it possible to dispense with the use of submersible pumps, which are potentially exposed to impeller clogging. This innovative technology not only improves the efficiency of the plant, but also reduces maintenance expenses.

The gravitational flow of wastewater in the treatment plant also contributes to reducing the operating costs of BIOFIT units. Thanks to this, the treatment plant consumes less energy than when using traditional pumps. The solution also ensures even flow of wastewater in the device.

BIOFIT treatment plants – operation

Does the BIOFIT wastewater treatment plant require constant maintenance during operation? You can additionally equip the kit with management software, which is able to report on the operation.

The BUMERANG system fitted with special oxygen probes and a sludge level sensor reports on blower run time, oxygen concentration and sludge level in the settling tank.

BIOFIT sewage treatment plants does not require constant supervision. Regular equipment inspection and sludge removal (1 to 5 times per year) should ensure high efficiency and failure-free operation of the system.

Concrete squares, trees cut down, tiny lawns and ubiquitous asphalt – this is more or less how most Polish cities look today. This phenomenon is called conretitis. The word perfectly reflects the nature of the problem, emphasising the almost morbid intensification of the trend of making the cities look concrete. Unfortunately, it is associated not only with a purely aesthetic issue, but also – or even primarily – with great difficulties for the Polish cities. Water drainage is inadequate, resulting in increasingly frequent flooding and inundation.

Concretitis – what does it actully mean?

In scientific and media discussions, as well as in public space, the word concretitis can be heard more and more often. The term, invented by Jakub Madrjas and popularised by Jan Mencwel, has become a symbol of the changes taking place in many Polish cities. Changes for the worse.

The trend to talk about concretitis in Poland began in 2019. It was then, during a summer heat wave, that Mencwel began publishing on Twitter a series of posts with photos of Polish town squares and urban spaces that, as part of an ill-conceived revitalisation, had turned from green squares into concrete-covered courtyards.

This has many unpleasant consequences. A simple thermometer test is enough to discover how rapidly the temperature rises in areas where trees have been felled. In the summer, trees serve as natural umbrellas that effectively protect us from the sun, giving us respite in the heat. Places without them become hotspots, deserts in which it is impossible to stand.

Trees provide shade, are great at storing water, inhibit street dust from entering homes, and filter the air. And these are just a few of their functions. Activists from the Krakow for Residents group took temperature measurements on streets planted with trees and those without. The conclusions are shocking. In certain spots without trees the temperature rises by as much as 20 degrees!

Floodingsof the Polish cities – where does the problem come from?

But the problem of tree felling is not everything. Concretitis is affecting the urban fabric in a wider context. Lawns are disappearing and being replaced by asphalt, cobblestones and other water-repellent materials. And this has serious consequences. One of these is flooding and flooding associated with heavy rainfall.

An example of poorly conceived revitalisation that has taken place in Poznań is the renewal of the Łazarski Square. Unfortunately, the modern design did not take vegetation into account, replacing it with geometric blocks and single flower pots.

Green-blue infrastructure

Urban concretitis is a disease that affects many cities, making it difficult for residents to function normally. Problems arise both in hot weather and during heavy rainfall. To stop this phenomenon, systemic measures are needed.

One of the changes Polish cities should make is to invest in green-blue infrastructure. This is based on a modern approach to climate change and the problems associated with it. As part of such work, localities are to change the way they are being developed. Green roofs, facades or elements related to sustainable water management should appear.

In urban, highly developed environments, these nature-based solutions (NBS) can support ecological activities. They can be successfully placed, for example, among elements of road infrastructure, in housing estates or office buildings. NBS are supposed to eliminate problems connected with concretitis in the cities by introducing elements necessary for reasonable management of, for example, water. In this way, a single element of such infrastructure can simultaneously contribute to safe rainwater collection, drainage and mitigation of urban heat island effects.

The Bydgoszcz revolution, a step towards a sustainable future

Bydgoszcz is one of the cities that have decided to carry out such a green-blue revolution. The city’s authorities decided to adapt it to climate change and invest more than 230 million PLN in the expansion of the rainwater system. Almost 20 kilometres of rainwater canals, numerous retention tanks and almost 30 rainwater treatment plants are currently being built.

A Hydrozone retention tank with a diameter of 8000 mm, a height of 5.4 m and an internal length of 17 m was installed in Bydgoszcz at Równa Street. The entire structure was made of high quality watertight concrete, and the capacity of the retention tank was 312 m3.

Construction of a rainwater retention tank on Równa Street in Bydgoszcz

Thanks to the changes that are taking place in the city, the problem of flooding and inundation will be reduced or perhaps eliminated altogether.

HYDROZONE retention tanks allow the retention, treatment and use of rainwater and snowmelt. There is also an increase in the possibility of safely draining excess water from city centres, which translates directly into more effective flood control measures.

This, fortunately, is already happening. More and more local authorities are recognising the importance of the problem and are starting to invest in green-blue infrastructure elements. And this saves us from the serious consequences of short-sightedness.

Rapid industrial growth, urbanisation and increasing consumerism are leading to an increase in the volume of generated wastewater. The waste stored and transported in sewer systems is not only a threat to health and the environment, but also generates offensive odours. An effective solution to this problem is to install filters that eliminate the smell and toxic substances.

Sewage treatment process and sewage odour nuisance

In order to explain the operation of anti-odour filters, we need to briefly outline the wastewater treatment process. It usually starts with mechanical filtration, where solid and liquid contaminants are separated by means of various grids or sieves. Mechanical treatment takes place in the primary settling tank, where sedimentation and flotation processes are used. Biological treatment, on the other hand, takes place in a reactor chamber with a fixed, submerged biological bed, which breaks down the pollutants into more environmentally friendly substances.

Unfortunately, each stage of this process can give rise to unpleasant odours. Their source (besides sewage treatment plants) are also pumping stations, grease separators, sewage wells, septic tanks or collection chambers.

Furthermore, we now have ever longer pressure pipes with ever smaller flow rates. Such large sewer systems result in wastewater being held for long periods of time in oxygen-restricted conditions, with the result that it rots and the systems become more foul.

Carbon based anti-odour filters – the solution to sewer smells

Anti-odour filters are usually installed where there is the greatest danger of odorous substances escaping. These are most often manholes leading to tanks with contaminants or vents.

This type of equipment uses the properties of activated carbon, as it has a high absorption capacity. It is this carbon that minimises the release of odorous and odourless substances. Additionally, the process of odour elimination is supported by an alkaline impregnation (chemisorption).

Activated carbon has an extremely porous structure, so that the surface area that comes into contact with airborne substances is exceptionally large. This affects both the effectiveness of the operation and the service life of the anti-odour filter itself.

Anti-odour filters effectively inhibit sewer smells

Anti-odour filters from Ecol-Unicon

Ecol-Unicon offers modern and robust sub-manhole and chimney filters belonging to the category of so-called passive neutralisers.

For example, in the KF model, a pipe chimney is fitted on the tank by sliding it into a sealed passage or socket previously embedded in the cover. The KFW fireplace inserts, on the other hand, have a ring with a rubber gasket at the top of the pipe, which rests on the fireplace housing. Unlike the first two models, the EZK system is equipped with a plate that allows installation with anchors.

Chimney filters are mainly designed for dry- and wet-well sewage pumping stations, as well as for domestic sewage treatment plants.

In the ENPeco sub-manhole filters the entire system consists of (apart from the carbon insert and neutraliser) a casing, supports, fastening elements, expansion plugs, screws, nuts and a threaded rod. The sub-manhole units are installed in collection wells and sewage sumps, infiltration systems and food processing plants.

In contrast, the ENA active neutraliser consists of a HDPE tank with activated carbon, a blower and a control system. Unlike passive devices, the insert used here does not filter mechanically, but neutralises odours and toxic substances using a chemisorption and adsorption reaction.

Key advantages of the Ecol-Unicon anti-odour filters

All models are made of materials highly resistant to prolonged contact with aggressive substances found in pumping stations and treatment plants.

Most importantly, the applied modern technical solutions enable simple, safe and independent replacement of just the insert without the need to replace the whole device, which significantly reduces operating costs.

Interested? Naturally, you will find our complete range of filters in the Ecol-Unicon! We would also be happy to advise you on choosing the right device for your particular facility and requirements.

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.

Grease separators are required in the sewer system by the Environmental Protection Act. Water contaminated with oils or fats must not be discharged into the public sewage system. Wastewater containing oils and fats easily clogs pipes if the fat hardens upon cooling. Corrosive vapours and fatty acids also attack cast iron pipes and quickly lead to damage.

Where does this need occur and how does it work?

The mandatory installation of fat separators applies to catering facilities, kitchens in mass catering facilities, butchers, meat and sausage factories, oil presses, canneries, abattoirs, fish processing plants, dairies and catering companies. Grease separators are essential because introducing fat into sewer systems causes many operational problems and has a negative impact on the operation of sewage treatment plants.

These problems are due to the fact that fat is not soluble in water, but rather is present in form of hardly decomposable, sticky lumps. Fat separators are therefore used to separate fats from waste water.

This is achieved by flotation, i.e. according to the gravity principle. Lighter, lipophilic substances move upwards inside the separator as a result of density differences. Lipophilic substances are those that tend to dissolve in fats and oils.  The sludge is collected in the lower part or in a separate chamber upstream of the separator and the grease-treated effluent is discharged further.

Before the water is treated, fat must be separated from it

How often should the grease trap be cleaned?

The frequency of cleaning depends on the amount of inflowing wastewater and its characteristics (concentration of grease and suspended solids). The recommended frequency of inspection and removal of pollutants is once every two weeks. According to EN 1825-2, fat separators should be drained and washed at least once a month, but it is safer to do it every 14 days.

When deciding on the type of separator, the most important factor to bear in mind is that emptying the separator should be as safe as possible for the environment. Below-ground separators are the most popular due to their price and practicality during emptying. After opening the covers of the device, the tank truck pumps out the contents of the separator. If there is not enough space outside to place the separator or if it is necessary to run a long waste water pipe, the separator should be placed inside the building. Otherwise a pipe that is too long will become overgrown.

It is best to consider installing two devices at the same time: a settling tank and a separator, or to choose a device integrated in one chamber. The advantage of the latter solution is, besides saving space necessary for installation, a faster and simpler assembly. Ecol Unicon grease separator EST-H has these exact advantages and is designed to treat wastewater with a hydraulic flow from 1 m³/s to 25 m³/s.

Never forget about checking the operation and cleaning of the existing separators

Scope of inspection

When emptying the unit each time, pay attention to:

  • visual assessment of technical condition of components,
  • checking the amount of accumulated fat and sludge layer (also in devices without a sludge section).

Current operations do not require going inside the manholes and can be carried out from the ground level. Removal of accumulated pollutants should be performed by a licensed company with appropriate equipment for collection, transport and disposal of pollutants and holding relevant permits. In order to ensure full comfort of users, together with the grease trap we also recommend using of sub-manhole odour neutralisers.