Case Studies

Water Treatment

Case Studies:

Legionella Management Plans installed across multiple locations for government customer in New York


A Government service provider had 16 facilities in a managing district. Each of these buildings contained at least one cooling tower, along with other water systems such as closed loops and boilers. Operations at each building were permitted to choose their own water treatment supplier. Six different water treatment suppliers serviced the sixteen buildings. The results at each facility varied; with each facility operating under different chemistries and programs, key factors such as cycles of concentration varied. Also, the methods of communication between service provider and facility management (as well as management at the district level,) varied as well.

Following the Bronx Legionella outbreak in July 2015, and the subsequent laws and regulations that followed, the status quo was deemed unsuccessful. A comprehensive program applied across all facilities in the district was desired.

The DuBois Solution

DuBois developed a complete Legionella Risk Minimization program for cooling applications at all 16 facilities. The programs used innovative Monitrol technology to deliver consistent results across all facilities. Routine service visits would monitor all key system parameters including bacteria and Legionella monitoring. Communication concerning test results, service reports, and any necessary corrective actions would be handled through the Data Management Program.

Results and Benefits

  • ASHRAE 188 compliant Legionella Water Management Plans were developed for all 16 sites.
  • The Monitrol chemical and equipment program installed across all the sites allowed for reliable, predictable, and consistent results across all facilities.
  • Legionella counts have remained under control.
  • Communication within specific facilities, as well as across all facilities, is easily handled by, which allows for easy generation of trend reports to evaluate results and find possible areas for continuous improvement.
  • When audited by government officials, the ease of access of records within easily demonstrated that the plan was being implemented as designed, and the plan was working to limit Legionella risk.