Chapter 4: Open Water Systems

4.1 General

• 4.1.1 This section deals with open water systems located inside or outside buildings, as part of the facility.
• 4.1.2 Open water systems include decorative water features such as fountains, waterfalls, and open pools.
• 4.1.3 Decorative water features are often located in the foyers or in common areas of many buildings and can pose a risk for Legionella bacterial growth.
• 4.1.4 In decorative water features, water is often sprayed or cascades over media, resulting in aerosols contaminated with bacteria.

4.2 Design Requirements

• 4.2.1 This section applies to new systems and to upgrades to existing systems.
• 4.2.2 Incorporate provision for maintenance at the design stage.
• 4.2.3 Locate drains or sumps at the lowest level of the reservoir, with no low points that are not served by drains or sumps.
• 4.2.4 Provide access to equipment for maintenance.
• 4.2.5 Avoid stagnant areas or areas that are difficult to clean; use circulating pumps to maintain water flow.
• 4.2.6 Do not locate decorative water features near kitchen exhausts, plants, truck bays, or other sources of contamination.
• 4.2.7 Avoid water stagnation near submerged lighting, to reduce the risk of Legionella growth due to warmer temperatures.
• 4.2.8 Airflows should be directed toward the water feature, to reduce the risk of exposure for people in the vicinity.

4.3 Operation and Maintenance

• 4.3.1 Any open water system not in operation for three or more consecutive days must be drained and shall have all components cleaned, disinfected, and then refilled.
• 4.3.2 Inspect visually for signs of microbial activity, algae, or debris.; inspection frequency to be at least once a week.
• 4.3.3 Clean all equipment and component water features at least once a week to reduce build-up of dirt, debris, and organic matter that can serve as nutrients for Legionella bacteria.
• 4.3.4 Disinfect system when bacterial testing results exceed action limits.
• 4.3.5 For disinfection, use an effective biocide program for microbiological control, complying with all federal, provincial/territorial, or municipal requirements.

4.4 Minimum Bacterial Testing Requirements

Water Sampling Locations

• 4.4.1 Water sampling locations for bacterial testing shall be in accordance with the facility Legionella Bacteria Control Management Program (LBCMP).
• 4.4.2 The facility LBCMP should consider, at a minimum, the following locations for water sampling:
  • 4.4.2.1 Water reservoirs
  • 4.4.2.2 Filter assemblies

Bacterial Testing Results

• 4.4.3 Record the bacterial testing results on the facility LBCMP testing form (LBCMP-4).
• 4.4.4 Report the bacterial testing results in accordance with the regional and national reporting protocols.

Minimum Bacterial Testing Requirements and Frequency (Normal Operation)

• 4.4.5 While the system is in normal operation, perform weekly dipslide tests to determine the total bacteria count (TBC) at each water sampling location. Refer to Figure 2 located in Appendix D.
• 4.4.6 While the system is in normal operation, every two months perform Legionella bacteria culture tests to identify Legionella pneumophila serogroup 1 (LPSG1), total Legionella pneumophila including all serogroups (LPTOT) and the Non-Legionella pneumophila Legionella (NLPL) bacteria levels. Refer to Figure 2 located in Appendix D.
• 4.4.7 One week after system start-up, perform a Legionella bacteria culture test to identify the LPSG1, LPTOT and the NLPL bacteria levels. Refer to Figure 2 located in Appendix D.

Minimum Bacterial Testing Requirements (Emergency Mode)

• 4.4.8 Use the emergency-mode bacterial test procedure if:
  • 4.4.8.1 There have been multiple reported cases of Legionnaires' disease in the past 30 days in the region within a 10 km radius of the building location and/or,
  • 4.4.8.2 The building has had recurring Legionella bacteria levels detected by the Legionella bacteria culture test that required disinfection of the system within the past 90 days and/or,
  • 4.4.8.3 Regional Health authorities direct more stringent bacterial testing.
• 4.4.9 Unless directed otherwise by the regional health authority, or due to regional restrictions, a weekly Quantitative Polymerase Chain Reaction (qPCR) test should be performed to obtain rapid, Legionella specific results, to determine the Legionella Pneumophila bacteria count at each water sampling location.

Dipslide Testing Limits and Actions

• 4.4.10 When the TBC is less than 10,000 colony forming unit (cfu):
  • 4.4.10.1 Continue with normal Operation and Maintenance (O&M).
• 4.4.11 When TBC is between 10,000 and 100,000 cfu:
  • 4.4.11.1 Review and adjust the O&M procedures and the water treatment program as required to ensure acceptable bacterial levels in the system.
• 4.4.12 When TBC exceeds 100,000 colony forming unit per millilitre (cfu/mL):
  • 4.4.12.1 Clean and disinfect the system within 48 hours.
  • 4.4.12.2 Review and adjust the O&M procedures and the water treatment program as required to ensure acceptable bacterial levels in the system.
  • 4.4.12.3 Wait one week then perform a Legionella bacteria culture test in accordance with clauses 4.4.13 through 4.4.16 below.

Legionella Bacteria Culture Testing Limits and Actions

• 4.4.13 Perform Legionella bacteria culture test in accordance with ISO 11731-1998 and ISO/TS 11731-2-2004.
• 4.4.14 When the LPSG1 count and/or the LPTOT count is less than 1 cfu/mL, and/or the NLPL count is less than 1,000 cfu/mL:
  • 4.4.14.1 Continue with normal O&M.
• 4.4.15 When the LPSG1 count is between 1 and 10 cfu/mL, and/or the LPTOT count is between 1 and 100 cfu/mL, and/or the NLPL count is between 1,000 and 10,000 cfu/mL:
  • 4.4.15.1 Clean and disinfect the system within 48 hours.
  • 4.4.15.2 Review and adjust the O&M procedures and the water treatment program as required to ensure acceptable bacterial levels in the system.
  • 4.4.15.3 Repeat the Legionella bacteria culture test after one week.
• 4.4.16 When the LPSG1 count exceeds 10 cfu/mL, and/or the LPTOT count exceeds 100 cfu/mL, and/or the NLPL count exceeds 10,000 cfu/mL:
  • 4.4.16.1 Shut down the system and immediately clean and disinfect the system.
  • 4.4.16.2 Review and adjust the O&M procedures and water treatment program to ensure acceptable bacterial levels in the system.
  • 4.4.16.3 Repeat the Legionella bacteria culture test after one week.

qPCR Testing Limits and Actions

• 4.4.17 Perform qPCR Test in accordance with ISO/TS 12869.
• 4.4.18 When the Legionella pneumophila bacteria count is less than 10 genome equivalents per millilitre (GE/mL):
  • 4.4.18.1 Continue with normal O&M.
• 4.4.19 When the Legionella pneumophila bacteria count is between 10 and 100 GE/mL:
  • 4.4.19.1 Review and adjust the O&M procedures and adjust the water treatment plan as required to ensure acceptable bacterial levels in the system.
• 4.4.20 When the Legionella pneumophila bacteria count exceeds 100 GE/mL:
  • 4.4.20.1 Clean and disinfect the system within 48 hours.
  • 4.4.20.2 Review and adjust the O&M procedures and the water treatment program as required to ensure acceptable bacterial levels in the system.
  • 4.4.20.3 Wait one week, then perform a Legionella bacteria culture test in accordance with clauses 4.4.13 through 4.4.16 above.

4.5 Operation, Maintenance and Testing Schedule

• 4.5.1 Table 4.1 below indicates a summary of the minimum frequency for operation, maintenance and testing requirements of open water systems.

Table Summary

This table indicates a summary of the minimum frequency for operation, maintenance and testing requirements of open water systems.

Table 4.1: Open Water Systems O&M and Testing Summary

Activity	Item	Frequency
Operation & Maintenance	Inspection	Weekly
	Cleaning	Weekly
	Disinfection	When required by bacterial testing results
Testing	Dip-slide test	Weekly, when system is in operation
	Legionella bacteria culture test	One week after system start-up When dip-slide test results indicate TBC > 100,000 cfu or qPCR test results indicate Legionella Pneumophila > 100 GE/mL Every two months when system is in operation
	qPCR Test	Weekly, when used during emergency mode