Department of Environmental Conservation

D E C banner

Cooling Towers & Pesticide Applications

Category 7G Certified Applicator - The application of biocides to HVAC systems (cooling towers, evaporative condensers) requires commercial pesticide applicator certification in Category 7G - Cooling Towers, Pulp & Paper Process issued by DEC. Please visit the Pesticide Applicator/Technician Certification webpage to view the eligibility requirements, training and exam information.

Individuals Applying Pesticides under the Supervision of a Certified Applicator - An individual making commercial application of pesticides who is not a certified applicator or technician must work under the supervision of a certified applicator, employed by the same facility, business or agency. Before the individual can apply general use products under the off-site direct supervision of a certified applicator they must receive 8 hours of core training and 40 hours of hands-on pesticide training. This individual, referred to as an apprentice, must also receive a determination from the supervising certified applicator that the apprentice is competent to apply pesticides as trained. The certified applicator must document this training and the determination of competence, and maintain a record of both.

Biocide/Pesticide Products - ALL products used to control pests MUST be registered with DEC and used in accordance with the product's label. Visit the NYS Pesticide Administration Database (NYSPAD) to confirm a product's registration status.

Product Label Notification - It is required that the pesticide applicator supply a copy of the pesticide label to the building owner (or owner's agent), which may then be supplied to the tenants of the building upon request. You may print a copy of the product's label from the NYSPAD database.

Business/Agency Registration - Any business location offering, advertising or providing the services of commercial application of pesticides and each agency that applies pesticides, must register with DEC. ALL businesses/agencies making biocide/pesticide applications, whether registration is required or not, MUST employ an individual that holds Category 7G Commercial Applicator certification.

Information, application and instructions for a Business/Agency registration can be found on DEC's Business/Agency Pesticide Information webpage, as well as, a complete list of all currently registered pesticide businesses and agencies.

Recordkeeping and Reporting of Pesticide Applications - Apprentices and certified applicators and technicians must keep records of their daily pesticide use. The Pesticide Reporting Law (PRL) requires all certified applicators and technicians file a report annually with the Department.

DEC Division of Water Requirements

The following requirements apply to batch treatment of cooling towers for treatment in accordance with the New York State Department of Health Legionella Regulations only.

Batch applications of chlorine and/or bromine based biocides for the above purpose shall comply with the following requirements:

  • The biocide shall be currently registered for application in New York;
  • The active biocidal ingredients consist solely of compounds which generate hypochlorous or hypobromous acid;
  • The inert/nonbiocidal ingredients in the biocide formulation shall consist solely of water, pH buffers, and stabilizers, and not contain any compounds at concentrations which may cause or contribute to a violation of water quality standards;
  • The water to be discharged shall be dehalogenated using sodium bisulfite or otherwise recirculated prior to discharge to a total residual chlorine or bromine of 0.02 mg/l or less, or comply with the currently effective SPDES permit effluent limit for total residual chlorine or bromine; and
  • The pH of the water must meet current effective SPDES permit effluent limit or, in the absence of a limit, between 6 and 9 SU prior to discharge.

The Water Treatment Chemical (WTC) Notification Form for the biocide to be used shall be scanned and submitted to Cooling Tower Submission email box. Test results verifying the pH and residual chlorine/bromine concentrations prior to discharge must be maintained on site for five years and made available to DEC upon request.

Individual approval is not required for applications of the aforementioned biocides in accordance with the above requirements. This approval is solely for and limited to the referenced application. Any other unapproved use of the above biocides will be subject to applicable and appropriate enforcement and/or penalty.

Use of other biocides or chemical for treatment of cooling towers in accordance with DOH Regulations must obtain individual approval by filing the WTC Notification Form to the Division of Water, Bureau of Water Permits.

For questions about these requirements, contact Brian Baker at Cooling Tower Questions email box.