Water quality recommendations for businesses reopening

Maureen BradyCity, Municipal Services and Operations

The City of Lawrence, as a community water provider, is offering tips for businesses and all water customers alike following the pandemic orders.

Because many businesses’ water lines laid dormant during the stay-at-home order, the necessary low levels of disinfectant to keep treated water safe may have dissipated, which increases the risk of microbial and bacteria Legionella contamination. Legionella contamination is additionally susceptible when hot water devices cool to temperatures that promote bacteria growth (77-108° F).


  1. Flush hot and cold water lines through all points of use (e.g., showers, sink faucets, soda fountains, automatic coffeemakers). Flushing may need to occur in segments (e.g., floors or individual rooms) due to facility size and water pressure. The purpose of building flushing is to replace all water inside the building piping with fresh water. Flush until hot water reaches its maximum temperature.
  2. Ensure water heater is properly maintained and temperature is set correctly. Determine if manufacturer recommends draining water heater after a prolonged period of disuse. Make sure water heater is set to at least 120°.
  3. Ensure cooling towers are clean and well maintained. Ensure the tower and basin are free of visible slime or biofilm before use. Ensure cooling towers are maintained (including start-up and shut-down procedures) per manufacturer’s guidelines.
  4. Clean all decorative water features, such as fountains. Ensure water features are free of visible slime or biofilm. Measure disinfectant levels after water feature has been refilled to ensure water is safe for use.
  5. Ensure hot tubs/spas are safe for use. Check existing guidelines from local and state regulatory agency before use. Ensure hot tubs/spas are free of visible slime or biofilm before filling with water.
  6. Ensure safety equipment including fire sprinklers systems, eye wash stations and safety showers are clean and well-maintained. Regularly flush, clean and disinfect these systems according to manufacturers’ specifications.
  7. Maintain your water system. After you water system has returned to normal, ensure that the risk of Legionella growth is minimized by regularly checking water quality parameters such as temperature, pH and disinfectant levels.

Low levels of disinfectant derived from chlorination in the treatment process serve as a critical safeguard against microbial contamination throughout the distribution system. Legionella is a pathogenic bacteria that can cause a pneumonia-type illness called Legionnaires’ disease and a mild flu-like illness called Pontiac fever. Luckily, these bacteria are not transmissible from person-to-person, and most people exposed to the bacteria do not become ill. For more information, please refer to the CDC Guidance for Building Water Systems.

Contact: Josh Carson, Public Information Officer, Municipal Services & Operations – jcarson@lawrenceks.org | 785-832-7822