1. Official Journal 2001.62.627 Environmental protection code.
2. Official Journal 2009.27.169 Regulation of the Minister of Environment from 28 January 2009.
3. Council Directive 91/271/ECC from 21 May 1991.
4. Podedworna J., Umiejewska K. (2008) Technologia osadow sciekowych, Publishing House of the Warsaw University of Technology, Warsaw.
5. Statistical Yearbook of the Republic of Poland (2008) Statistical Publications House, Warsaw.