Evaporative cooling systems, cooling towers, and wet separators; Notices and announcements
Operators of evaporative cooling systems, cooling towers, and wet scrubbers are required, among other things, to use state-of-the-art technology during installation and operation and to implement organizational measures.
Status: 17.09.2026. Link zum BayernPortal
Online Procedures
Cadastral Register for the Recording of Evaporative Cooling Systems (KaVKA-42.BV)
Evaporative cooling systems, cooling towers, and wet scrubbers that fall within the scope of the Regulation Implementing the Federal Immission Control Act (Regulation on Evaporative Cooling Systems, Cooling Towers, and Wet Scrubbers — 42nd BImSchV) must be reported to the competent air pollution control authority. Operators of these systems must also comply with additional requirements.
Under the 42nd Ordinance Implementing the Federal Immission Control Act, operators of such systems are required, among other things, to apply state-of-the-art technology during construction and operation. Systems falling within the scope of this regulation must be designed, constructed, and operated in such a way that contamination of the process water by microorganisms, particularly Legionella, is prevented in accordance with the state of the art. Pursuant to the 42nd BImSchV, these systems must be reported to the competent immission control authority. This can be done nationwide via the KaVKA Cadastre website (https://kavka.bund.de/). In Bavaria, a general ruling stipulates that the notification must be submitted exclusively through this portal. In addition, the 42nd BImSchV specifies test and action values for concentrations of Legionella in potable water.
Legionella are aerobic bacteria classified as potentially pathogenic to humans. They are widespread environmental microorganisms that occur, for example, in small numbers in surface waters. Inhaling water droplets (aerosols) containing Legionella can lead to pneumonia, which in some cases may even result in life-threatening infections. Human cases occur repeatedly worldwide, either sporadically or as part of outbreaks. In recent years, there have also been Legionella outbreaks in Germany resulting in fatalities, for example in Ulm in 2010 and in Warstein in 2013. In addition to contaminated drinking water, evaporative cooling systems, cooling towers, and wet separators can also be sources of Legionella. Under certain conditions, these systems can release water droplets containing Legionella into the outside air. The goal of legal regulations is to inhibit Legionella growth and reduce the emission of Legionella-containing aerosols from these systems.
The ordinance includes, among other things, the following legally binding reporting and notification requirements for the operator:
- Obligation to inform the competent authorities if the action thresholds are exceeded (Section 10, sentence 1)
- Obligation to report a new system (Section 13, paragraph 1)
- Obligation to report an existing system (Section 13, paragraph 2)
- Obligation to report changes to the system or the decommissioning of the system (Section 13, paragraph 3)
- Obligation to report a change in operator (Section 13, paragraph 4)
- Obligation to have the facility inspected by an expert (Section 14(1) in conjunction with (2), first sentence)
- Requirement to report the results to the authority (Section 14(2), second sentence)
- Submission of an application for exemptions, if required (§ 15).
Notifications pursuant to Section 13 of the 42nd BImSchV and reports pursuant to Section 10 of the 42nd BImSchV must be submitted online via the website of the “Register for the Recording of Evaporative Cooling Systems under the 42nd BImSchV — KaVKA-42.BV.”
Notifications pursuant to Section 14 of the 42nd BImSchV may also be submitted via this website.
Applications for exemptions under Section 15 of the 42nd BImSchV may be submitted informally to the competent district administrative authorities.
The reporting requirement under Section 13 of the 42nd BImSchV took effect on July 19, 2018. The operator of a new facility must report it to the competent authority no later than one month after the initial filling with process water. Existing facilities had to be reported to the competent authority by August 19, 2018, at the latest. Section 13 also specifies additional deadlines for reporting changes to or decommissioning of a facility, as well as a change in operator.
Pursuant to § 10, the operator must immediately notify the competent authorities in accordance with Annex 3, Part 1, and must notify them within four weeks in accordance with Annex 3, Part 2, as soon as a laboratory analysis reveals that action levels have been exceeded.
Pursuant to § 14(2), the operator must report the results of the inspections required under § 14(1) to the competent authority within four weeks of the inspection’s completion.