The Condition of the Sanitary Infrastructure in the Bialski District in Poland and the Need for its Development

The aim of this paper was to present the current state and the need for development of the sanitary infrastructure in the communes of the Bialski District located in the Lublin Voivodeship. The Bialski District encompasses 2 urban communes: Miedzyrzec Podlaski and Terespol and 17 rural communes: Biała Podlaska, Drelów, Janów Podlaski, Kodeń, Konstantynów, Leśna Podlaska, Łomazy, Międzyrzec Podlaski, Piszcząc, Rokitno, Rossosz, Sławatycze, Sosnówka, Terespol, Tuczna, Wisznice and Zalesie. The present paper uses the data from the surveys conducted in these communes in 2016. On average, 79.2% of the population used the water supply system in the surveyed communes, while 39.4% of the inhabitants had the possibility of discharging wastewater to the sewerage system. In the area of the communes, there were 20 collective, mechanical and biological wastewater treatment plants with a capacity exceeding 5 m3/d. The households which were not connected to the wastewater network, discharged wastewater mainly to non-return tanks. In the surveyed communes, there were 4437 household wastewater treatment plants. Most of them (above 80%) were the systems with infiltration drainage, which do not ensure high efficiency of pollutants removal and may even contribute to the degradation of the groundwater quality. In order to solve the existing problems of wastewater and water management occurring in the communes where the Bialski District is located, it is necessary to further develop collective wastewater systems and equip the areas characterized by dispersed housing with highly efficient household treatment plants, e.g. constructed wetlands.


INTRODUCTION
After the accession to the European Union, Poland undertook to comply with the legal provisions on the rational management of water resources and their protection. The changes that occurred in the national law concerning water management have prompted local government units to take action in the field of development of water and sewage infrastructure [Jóźwiakowski et al. 2012]. This contributed to the growth of investments in the area of urban and rural sewerage. Apart from the ecological and economic effects, the development of technical and sanitary infrastructure brings many social and economic benefits, as they contribute to the improvement of living conditions of the inhabitants and the development of entrepreneurship.
The statistical data from recent years indicate a significant increase not only in the length of the water and sewage system but also the number of facilities used for water supply and wastewater disposal in Poland. In recent years, the length of the water supply network has increased from 245.6 thousand km in 2005 to 301 thousand km in 2016. It was observed that the length of water supply network increased by 146% in rural areas and by about 47% in cities [CSO 2016]. The number of people using sewerage network and the number of wastewater treatment plants is still increasing. In urban areas, characterized by huge population, the majority of sewage is treated in collective facilities that are joined for the whole cities or communes. However, in rural areas, often characterized by dispersed settlement, people generally use septic tanks and different household wastewater treatment plants.
Although the general state of sanitary infrastructure in Poland has improved over the recent years, the disproportions in equipping cities and villages with water supply and sewage systems still exist, especially in rural areas.
The aim of this study was to assess the state and needs of the development of sanitary infrastructure in the Ryki District. The basis of the study were the results of a survey conducted in 2016 by the Department of Environ mental Engineering and Geodesy of the Univer sity of Life Sciences in Lublin and the data from the Statistical Office in Lublin [CSO 2016]. Questionnaires were sent to all the communes of the Ryki District, but sometimes no feedback was received. Then, the data from CSO was used [2016]. The researchers wanted to investigate, among others, the length of the water supply network and the sewage system as well as number of people with an access to them, number and types of collective and household wastewater treatment plants but also the number of non-effluent tanks (septic tanks) functioning in each commune. The obtained data was analyzed and the results were presented in tabu lar and graphical forms.

THE CHARACTERISTICS OF THE RYKI DISTRICT
The Ryki District is located in the northwestern part of the Lublin Voivodeship in Poland (Fig. 1). The Ryki District borders with the following districts: the Łuków District -to the north-east, the Lubartów District -to the east, the Puławy District -to the west and the Garwolin District (Masovian Voivodeship) -to the northwest. The area of the Ryki District is 615.5 km², so it is one of the smallest districts in the Lublin Voivodeship (2.5% of the voivodeship area). Within the discussed district there are both 4 rural communes -Stężyca, Ułęż, Nowodwór and Kłoczew, 1 urban commune -Dęblin and 1 urban-rural commune -Ryki, which is the official seat of the Ryki District (Fig. 2). It is also the largest commune in the whole district (26% of the district area), whereas the urban Dęblin Commune constitutes only 6% of the Ryki District area (Table 1).
In 2016, above 57 thousand people lived in the discussed district; the average value of population density was 93 people/km² [CSO 2016]. According to the collected data in 2016, the most people lived in the Ryki Commune (about 37%) and the Ułęż Commune had the least inhabitants (about 6% of the whole district population). When it comes to the share of people living in rural and urban areas, it was observed that in 2016 about 54% of the district inhabitants lived in the countryside and 46% -in towns. The Ryki District is marked not only by a negative natural growth, but also a negative net migration rate [CSO 2016]. The land utilization in the discussed district is quite diverse and the largest part of the area is occupied by arable farming (above 50%) forests (above 21%) and grassland (above 13%) [Waste management plan for the Ryki District for the years 2010-2013 with an outlook until 2017]. Generally, the Ryki District is poorly industrialized, the most of people work in the agricultural sector. In 2016, about 5.5 thousand farms existed in the district, most of which were quite small (2-10 ha). It is estimated that about 70% of the farm produce is allocated for the market and the remaining part for own purposes. The specialization of agricultural production is oriented to the needs of agri-food processing plants. Among the crops, a significant area is occupied by strawberries, raspberries, currants and cherry orchards. A special kind of agricultural production in the district are fish farms, which are located, among others in: Jagodne (the Kłoczew Commune) -about 220 ha, Sobieszyn -205 ha, Ułęż -about 77 ha and in Ryki -283 ha (http 3). The Ryki District is characterized by a quite small share of areas with nature protection -about 11%.

Water supply network and sewage system
Polish water and wastewater management is still in the development phase. The length of water supply system and sewage network is still growing but definitely too slowly. Over the recent years, a huge disproportion in the rate of these two systems extension has been observed, also in the Ryki District described in this paper, which is depicted in Figure 3.
While comparing the length of the elements of the sanitary infrastructure in 2016 in individual communes of the Ryki District (Table 2) it can be noticed that the longest water supply network was observed in the Kłoczew Commune, while the shortest in the Ułęż Commune. On the other hand, the urban Ryki Commune had the longest sewage system, while the Ułęż Commune had the shortest one. Totally, in 2016 the length of the water supply network in the whole Ryki District amounted to about 710 km, while the length of the sewage system was about 130 km.
However, only on the basis of the length of these two systems, it cannot be stated which commune is the one with the poorest state of the sanitary infrastructure. This is determined by many different factors, such as the size of the discussed territorial unit or the housing density [Jóźwiakowska and Marzec 2020]. Another very important indicator is the percentage of people with an access to the water supply network and to the sewage system (Table 3).
On the basis of the data presented in the Table 3 it can stated that in 2016 the Stężyca Commune had the smallest level of water supply, because only 9.8% of its inhabitants were connected to water pipe. The opposite was the Ułęż Commune, where all the inhabitants had an access to the water supply network. In 2016, the commune with the smallest level of wastewater management was the Kłoczew Commune, because only 1.5% its inhabitants had an access to the sewage system. On the other hand nearly 90% of the inhabitants of the Dęblin Commune had an access to the sewage system and in 2016 this was the prime commune according to the sewage system in the whole Ryki District. Totally, in 2016 the percentage of the inhabitants of the Ryki District who were connected to the water supply network amounted to above 71% and to the sewage system -about 42%.
Another aspect that is very important while comparing the state of the sanitary infrastructure in different territorial units is the indicator expressing the length of the water supply network or the sewage system per one inhabitant using the discussed system. Thus, Table 4 shows the calculated indicators.
It was calculated that the communes with the longest water supply network per one inhabitant were the communes of Stężyca and  In order to assess the state of the water supply and sewage system independently, the Ryki District was compared with some other districts, also located in the Lublin Voivodeship (Fig. 4). The water supply network occurred to be the poorest in the Ryki District and in 2016 only 71% of this district inhabitants had connection to water, while the situation was better in other districts: 79% of the population in the Biała Podlaska District [Jóźwiakowska and Marzec 2020], 88% in Parczew [Micek et al. 2018] and 90% in Radzyń [Bogusz et al. 2020]. Although in 2016, the Radzyń District was characterized by the highest percentage of the inhabitants with connection to the water supply network, this district had also the least people (35%) with an access to the sewage system. In other districts of the discussed group, the situation was a bit better -in the Biała Podlaska District, joint sewage disposal was used by 39% of the inhabitants, 42% in Ryki and 48% in Parczew. Huge disproportions can be observed in the rate of the development of the water supply network and the sewage system and it seems to be the characteristic feature of the sanitary infrastructure in the rural areas in the Lublin Voivodeship

Collective wastewater treatment plants and joint sewage disposal
Another important aspect of the state of the sanitary infrastructure of the Ryki District that must be discussed corresponds to wastewater treatment plants. According to the data collected in 2016, there were 5 collective wastewater treatment plants with a capacity greater than 5 m 3 /d ( Table 5).
The data presented in the table above shows that the largest collective wastewater treatment plant was functioning in the urban Dęblin Commune and it treated 6000 m 3 of sewage per day. The second largest object was located in the Ryki Commune -3607 m 3 /d. Other wastewater treatment plants were projected for many times smaller capacity. The Ryki Commune was equipped with the smallest collective wastewater treatment plant and its capacity was only 12 m 3 /d. The Stężyca Commune did not have its own object and the sewage produced by the inhabitants of this commune was delivered to the wastewater treatment plant in Dęblin.
While comparing four different districts of the Lublin Voivodeship (Table 6) it should be emphasized that although the Ryki Distrct had only 5 collective wastewater treatment plants, their total capacity was the greatest from all the other districts and amounted up to 9819 m 3 /d. In 2016, the Biała Podlaska District was the one with the greatest number of collective wastewater treatment plants that amounted up to 20 objects with a total capacity of more than 6805 m 3 /d [Jóźwiakowska and Marzec 2020].

Local systems of wastewater disposal
Rural areas are often characterized by dispersed building and on such areas it is not viable to develop joint sewage disposal systems. The National Urban Wastewater Treatment Programme (KPOŚK) states that the number of inhabitants per one kilometer of the wastewater network should exceed 120 people, so as to connect them to a collective wastewater system. Otherwise, this would enforce huge length of the network and the inhabitants would be forced to pay a lot for the sewage connection. The households that have no access to the sewage network discharge wastewater to non-return tanks or invest in own household wastewater treatment plants.
Septic tanks that hold sewage which is then delivered to the collective wastewater treatment plants are popular in rural areas and they have been used for many years. However, this solution   Household wastewater treatment plants seem to be a better solution to cope with sewage in the same place where it is produced. There are many different types of such small objects but their capacity is always less than 5 m 3 /d [Water Law 2017 with further changes]. The type of a household wastewater treatment plant used in every situation is chosen on the basis of many factors, such as land availability, number of people in a household, technological reliability and also an economic aspect Mikosz 2009, Jóźwiakowski et al. 2015]. There are many different types of small wastewater treatment plants, such as: settling tank with drainage system, settling tank with sand filter, container objects with activated sludge or biological bed and constructed wetlends [Pawełek and Bugajski 2017]. According to the data collected in the survey in 2016, only 3 out of 6 communes of the Ryki District recorded the number and types of household wastewater treatment plants. In the rural Kłoczew Commune, only one hybrid household wastewater treatment plant was identified, it combined the method of activated sludge and biological bed. In the Nowodwór Commune, 12 objects with drainage systems and also 221 facilities with activated sludge and 13 constructed wetland wastewater treatment plants were found. Moreover, in the Ułęż Commune, 9 drainage systems and 185 facilities with activated sludge were identified. Generally, it was shown that the activated sludge method was the most popular type of all the household wastewater treatment plants in the Ryki District. The share of selected small wastewater treatment plants in the discussed area was shown in figure 5. The overwhelming majority of the household wastewater treatment plants in the discussed district were activated sludge systems (92%). There were also some objects containing settling tank and drainage systems (4.8%).
While comparing the discussed area with other districts in the same voivodeship, it was observed that for example, primarily drainage systems were found in the Biała Podlaska District -above 75% of all the small wastewater treatment plants [Jóźwiakowska and Marzec 2020]. The similar situation was found in the Parczew District, where in 2016 all the existing household wastewater treatment plants were the systems consisting of a settling tank and infiltration drainage [Micek et al. 2018]. However, in the Radzyń District, conventional biological wastewater treatment plants played in 2016 a significant role [Bogusz et al. 2020]. According to many authors, greater emphasis should be placed on promoting different solutions of highly-effective domestic wastewater treatment. There still seems to be a strong need to implement constructed wetland systems, which are recommended for rural areas.