Legionella: A Rising Threat to Water Management Health & Safety Part 3
Developing and maintaining a water management program is a multi-step, continuous process. It is important to have a plan that is comprehensive and tested for effectiveness. The steps listed here will outline the key elements of an efficient water management system:
1. Establish a water management program team
Consider who among your employees, partners, and outside experts can provide these skills so that you can develop the most effective program possible. Those who might be part of your water management program team include:
-Maintenance or engineering employees
-Equipment or chemical suppliers
-Contractors/consultants (e.g., water treatment professionals)
-Certified industrial hygienists
-Environmental health specialists
-State and local health officials
In some cases, you may need to train your in-house personnel or hire professionals with specific experience in Legionella bacteria in building water systems.
2. Describe the building water systems using text and flow diagrams
This description should include details like where the building connects to the municipal water supply, how water is distributed, and where pools, hot tubs, cooling towers, and water heaters or boilers are located. An existing as-built diagram of the plumbing system and fixtures may be useful in developing this description. In addition to developing a written description of your building water systems, you should also develop a process flow diagram.
3. Identify areas where Legionella could grow and spread
Once you have developed your process flow diagram, identify where potentially hazardous conditions could occur in your building water systems. If you find that a control limit (i.e., temperature levels, disinfectant levels) is not being met, you need to take corrective actions to get conditions back to within an acceptable range.
4. Decide where control measures should be applied and how to monitor them
Control measures and limits should be established for each control point. Control limits, in which a chemical or physical parameter must be maintained, should include a minimum and a maximum value. Examples of chemical and physical control measures and limits to reduce the risk of Legionella growth:
-Water quality should be measured throughout the system to ensure that changes that may lead to Legionella growth (such as a drop in chlorine levels) are not occurring.
-Water heaters should be maintained at appropriate temperatures.
-Decorative fountains should be kept free of debris and visible biofilm.
-Disinfectant and other chemical levels in cooling towers and hot tubs should be continuously maintained and regularly monitored. Surfaces with any visible biofilm (i.e., slime) should be cleaned.
5. Establish ways to intervene when control limits are not met
Building water systems are dynamic. You should plan for your monitoring results to vary over time and be prepared to apply corrective actions. Corrective actions are taken in response to
systems performing outside of control limits. For examples of corrective actions, review: ASHRAE 188: Legionellosis: Risk Management for Building Water Systems June 26, 2015.
ASHRAE: Atlanta. www.ashrae.org
Next week, Alliance Environmental Group and Airtek Indoor Solutions will discuss how to insure that your water management system is running as designed and is effective. Though our assistance is in line
with industry standards, it is imperative to follow all relevant federal, state, and local laws, regulations, and ordinances for your specific building.
For additional information about the growth and spread of Legionnaires’ disease, visit: www.cdc.gov/legionella.
Alliance Environmental Group, Inc. is a leading environmental contractor in California, with more than 75 years of experience. Alliance Environmental Group and Airtek Indoor Solutions provides innovative resolutions in the areas of: asbestos, lead, and mold abatement; air and HVAC duct cleaning; heat treatment for pest control; structural pasteurization; demolition and emergency response. The company has successfully completed over 120,000 remediation projects in California and surrounding areas.
For additional information about the company and its services, visit: www.alliance-enviro.com.