# Municipal Sewage Sludge Disposal in the Republic of Poland
## 5 Methods of Disposal of Sewage Sludge  
### Agriculture  
As mentioned earlier, in 2022, agriculture was the most popular method of sewage sludge management in Poland (27.1%), accounting for 157.4 thousand Mg of total solids in the sludge [22]. Biological and chemical safety are important when using municipal sewage sludge to grow plants intended for human consumption and feed production. It is impossible to allow large amounts of harmful chemicals to enter the soil or groundwater [4; 41; 42]. In the Republic of Poland, according to the Act on Waste, the R10 recovery process involves processing on the ground surface, which benefits agriculture or improves the condition of the environment. According to the implementation regulations, municipal sewage sludge may be used on land if the following conditions are met [31]:  
1. \"The content of heavy metals in the sludge does not exceed the amounts specified in Annex No. 1;
2. In the case of using this sludge in agriculture and for land reclamation for agricultural purposes, no bacteria of the Salmonella genus were isolated from a representative sample of sludge weighing 100 g obtained in SS 5;
3. The total number of live eggs of the intestinal parasites _Ascaris_ sp., _Trichuris_ sp., and _Toxcanx_ sp. in 1 kg of total solids, hereafter referred to as \"TS.\" of sludge intended for research use: 1. In agriculture and for land reclamation for agricultural purposes is 0; 2. For land reclamation is no more than 300; 3. For adapting land to specific needs resulting from waste management plans; spatial development plans, or decisions on the conditions of development and land development is no more than 300; 4. For growing plants intended for compost production is no more than 300; 5. For growing plants not intended for consumption and the production of feed is no more than 300\". In addition, the amount of heavy metals in the top layer of soil at a depth of 0-25 cm, on which these sludges are to be applied, does not exceed the permissible values specified in Annexes 2 and 3, and the pH value of the soil is not lower than 5.6. The use of sludge must not cause deterioration of the quality of soil, earth, and surface and underground waters. The use of sludge is possible outside the period of growth and development of plants intended for direct human consumption. The regulation specifies the permissible dose of municipal sewage sludge depending on the type of land, its use, the quality of municipal sewage sludge and soil, and the demand of plants for phosphorus and nitrogen. The permissible doses of municipal sewage sludge may be used during the year per unit of land area provided that the allowable content of heavy metals in municipal sewage sludge specified in Annex 1 to the regulation is observed [31]. The conditions that municipal sewage sludge must meet and the land on which it can be used have been strictly defined in the regulation. This recovery method can be implemented by sewage treatment plants that produce sludge that meets the required quality standards, especially regarding heavy metal content. In addition, there are areas within the province where municipal sewage sludge can be used. The requirements set in the regulation create restrictions, especially for large sewage treatment plants located in agglomerations that produce sludge containing heavy metals. In such cases, treatment plant operators are forced to use other methods of processing municipal sewage sludge. Municipal sewage sludge is permitted on agricultural land in both Czechia and Japan. In the field of sewage sludge processing, the legislation of Czechia, as a Member State of the European Union (EU), is based on Directive 86/278/EEC [24], which sets limits for heavy metals and other pollutants in sludge. Japan also has limits for heavy metals for the agricultural use of sewage sludge. However, organic pollutants and pathogens do not have direct limits. In Czechia, as shown in the literature, two-thirds of the produced sludge is disposed of by direct application in agriculture or composting [43].