The idea of constructing a treatment plant for wastewater of the areas of the then municipalities of Domžale and Kamnik goes back to 1975, when in July a document titled »A Study of industrial wastewater of the towns of Domžale, Kamnik, and Mengeš« was drawn up for this purpose by the Institute for Waters of the Republic of Slovenia. Due to its developed and diverse industry, the area of Domžale-Kamnik was already at that time one of the potentially most polluted areas in Slovenia. However, the result of the care and efforts of our forerunners in the field of river protection led to the beginning of the construction of the Central wasterwater treatment plant of Domžale – Kamnik in 1975. The construction itself was funded not only by the state, but also the biggest water polluters in the area, the current municipalities of Domžale and Kamnik as the then municipalities of Domžale and Kamnik, and the owners of the Central wastewater treatment plant of Domžale-Kamnik (hereafter referred to as the CČN).
The current workload of the CČN, treating municipal wastewater, rainwater and industrial wastewater from the areas of the municipalities of Domžale, Kamnik, Mengeš, Komenda, Cerklje na Gorenjskem and Trzin, ranks this plant the fourth biggest municipal wastewater treatment plant in operation in the Republic of Slovenia. Our treatment plant is of conventional type and is responsible for the removal of carbon from wastewater. The plant is a classic, two-stage, mechanical-biological wastewater treatment plant with anaerobic digestion and biogas use in its biogas engines. The process is finished with the treated wastewater released into Kamniška Bistrica, a mountain river with fast current which flows into the Sava river.
|Development of the CČN Domžale-Kamnik in chronological order:|
|construction of the sewer network||1972–1975|
|construction of the treatment plant||1975–1980|
|launch of CČN (without anaerobic digestion and sludge dumping ground)||1981|
|modernization of the plant||1981–2000|
|construction of the wastewater dehydration system||1986|
|digestion plants for stage II||1991|
|power supply building||1993|
|facility A - skimmers||1990|
|change of the ventilation system||1999|
|mechanical level of treatment: sludge skimming optimization||1999|
|old digestion plants, capacity expansion in the heating system||1999–2000|
|sanitation of the primary sediment tank||2003–2004|
|change of biogas engines||2004|
|upgrade of CČN||2014–2017|
With the addition of processes for the removal of carbon and phosphorus, as well as with the increased wastewater inflow capacity of the plant, the CČN was upgraded, representing a model of the current state-of-the-art technique in wastewater treatment in the world.
This upgrade allows additional wastewater reception from the areas where the sewer system is still in works, more precisely from the current reception municipalities as well as from the municipality of Cerklje na Gorenjskem. The upgrade of CČN is by all means bound to lower substantially the levels of organic material in Kamniška Bistrica, including less carbon and phosphorus content, which shall effect positively both chemical and biological conditions of the river.