Cooling tower basins without effective filtration or good water treatment can be breeding grounds for Legionella and other bacteria. The American Society for Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) has developed standards and guidelines to prevent the growth of Legionella, which includes cooling tower filtration.
Guideline 12 in the ASHRAE Handbook points out that...“Keeping the system clean reduces nutrients available for Legionella growth...(and) centrifugal gravity-type separators and bag-type filters can be used to assist in removal of debris.” Fighting Legionella is just one of the advantages of using a centrifugal separator to clean a cooling tower water system.
The newly published ASHRAE Standard 188 (Risk Management for Legionella) requires building owners to document a plan for regular inspections and maintenance of cooling towers. Section 7.2.3 b clearly states that this plan “shall include requirements and schedule for basin or remote sump cleaning.” The ASHRAE white paper, “Benefits of Cooling Water Filtration,” explains other benefits of cooling water filtration.