In days gone by most industrial facilities such as refineries chemical plants manufacturing plants etc. had an internal “water doctor” that had a good overall working knowledge of the cooling and boiler systems and the water technology needed to protect them from corrosion scale and microbiological growth. This individual audited the performance of water treatment chemical supplier (water treatment service company) prepared specifications for water treatment and stayed abreast of current water treatment technology. For the most part that position no longer exists in many corporations. Responsibility has been pushed mainly onto the water treatment service company with end user personnel having few resources to do a thorough job of providing oversight. This paper is intended to help the end user manage the activities of the water treatment service company in order to ensure that the cooling and boiler systems in the plant are properly treated and protected.