This paper by IMEG’s Jeff Boldt and Joshua Ince, P.Eng., of DuBois Chemicals, summarizes the most important items for the HVAC designer to know about master specifications for water treatment, which is required on projects for many reasons. Reprinted with permission from ASHRAE, this paper was originally published as the “Engineer’s Notebook” in the March 22, 2022, issue of the ASHRAE Journal.