Boards must also keep a Maintenance Program and Plan onsite for each cooling tower, test the water every week, and test for Legionella bacteria every 90 days. Building owners are also required to enlist a responsible person(s) defined as someone retained by an owner who is capable of making recommendations and diagnosing conditions that require corrective actions, under the guidance of a qualified person to conduct: 

  • Routine System Monitoring (at least weekly) 
  • Routine System Maintenance (frequency based on manufacturer recommendations and/or industry best practices) 
  • Water Quality Monitoring (three times per week, with no more than two consecutive days without measurement) 

Dip Slide – Weekly 

The method to test for microorganisms (such as HPC) consisting of a sterile culture medium affixed to a sterile slide, that is dipped directly into the liquid that is to be sampled. 

Weekly Chemical Usage – Weekly 

A bacteriological indicator to estimate microbial content of recirculating water must be collected at least once each week while the cooling tower system is operating. Indicators must be taken at times and from water sampling points, as detailed in the maintenance program and plan, that will be representative of water microbial content. 

Water Quality Parameter – 3x per week 

Manual measurements. At least three times each week, provided that no more than two days pass without such measurement when the cooling tower system is operating. 

Visual Inspection – Weekly 

The responsible person must enter on a written or electronic checklist provided and maintained by the owner all visual observations of the cooling tower system and associated equipment.