Legionella Prevention: Cleaning/Disinfection, Inspection, and Sampling for Cooling Units

New York State Department of Health (NYSDOH) Protection Against Legionella Regulations effective July 6, 2016 (Regulations) describe requirements to protect individuals that may be affected by Legionella bacteria as a result of cooling tower or evaporative cooler operations (cooling units). The NYSDOH Regulations aim to reduce the risk of Legionella transmission with periodic maintenance and quality control at all facilities which contain cooling units, under the guidance of a Professional Engineering firm.

The crucial actions required by the Regulations are as follows:

Cooling units must be physically cleaned and disinfected when turned off for more than five consecutive days. Additionally, chemical treatment must continue to be administered at all times while each cooling unit is in use.

Cooling units are typically used on a seasonal basis between April and October throughout New York State. A pre-startup cleaning and disinfection of each cooling unit must be performed immediately prior to seasonal startup. The most efficient way to perform this task is using a high-powered water source (power washer) combined with a USEPA-approved biocide to effectively remove accumulated scale, algae, and other debris which may form on both interior and exterior surfaces of cooling units. Facility owners may elect to perform the work in-house or have the work performed by a third-party contractor. The engineer shall directly oversee this work to certify that all actions comply with NYSDOH Regulations.

Furthermore, the process water for each cooling unit must be treated chemically with an approved biocide at all times while the cooling unit(s) is operational. This can be achieved through manual injection (e.g. floating dispenser) or through an automated injection system to maintain a consistent chemical concentration throughout the system.

Cooling units must be inspected every 90 days while in use.

The first inspection during the cooling season shall be performed by the engineer once the physical cleaning and disinfection work is complete, and every 90 days thereafter while each unit is operating. The inspection shall be an overall assessment of the physical condition of the cooling units with respect to Legionella transmission, and the effectiveness of the chemical treatment process in inhibiting future growth of the bacteria. Once the inspection is complete, the engineer shall share the findings with the facility owner. Both parties shall retain a copy of the inspection form(s) for their records in accordance with the Regulations.

Cooling units must be sampled every 90 days while in use, and no later than 14 days after system startup for the cooling season.

The engineer shall collect water samples from each cooling unit’s water basin for analysis via ISO Method 11731 for the presence of Legionella bacteria every 90 days while the cooling unit(s) are in use. The analysis must be performed by a Centers for Disease Control and Prevention ELITE (Environmental Legionella Isolation Techniques Evaluation) Program-certified laboratory. The sample results dictate whether the system can continue running at its current state, or if emergency response actions must be taken to prevent the spread of bacteria.

To learn more about how Walden can assist you in keeping your cooling units Legionella-free and in compliance with the NYSDOH, please give us a call at (516) 624-7200.

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