When two residents of a Midtown Manhattan building contracted Legionnaires’ disease within six months, hospitals were required to notify the NYC Department of Health (DOH), triggering an urgent investigation. Testing revealed widespread Legionella bacteria contamination in the building’s hot water system, posing a serious health risk to 400 residential units, four commercial spaces, and a school.
The DOH commissioner issued an order with strict deadlines, mandating the building to take immediate action:
• Within 24 hours: Notify occupants of test results.
• Within 3 days: Submit ownership details and a full plumbing system distribution report.
• Within 7 days: Hire a Legionella-specific consultant, complete a risk assessment, and provide a water distribution schematic.
• Within 10 days: Develop a Legionella sampling plan and implement it upon DOH approval.
• Within 3 additional days (if needed): Revise the plan per DOH feedback.
• Within 3 days of DOH approval: Complete the revised sampling plan.
If Legionella is detected, the building must quickly escalate response efforts:
• Within 3 days: Assemble a water management team, including building representatives, a Legionella consultant, and an independent third-party expert.
• Within 21 days: Develop an Acute Remedial Treatment Plan (ARTP).
• Within 7 days off DOH approval: Implement the ARTP, including follow-up sampling.
• Within 7 days post-remediation: Conduct initial post-ARTP sampling, followed by another round 30 days later.
• Within 10 days: Establish and implement a Long-Term Water Management Plan.
Metro Group’s Rapid Legionella Remediation
The building first turned to its existing water treatment vendor for help but found they lacked the expertise to navigate the DOH process, prompting the property manager to turn to Metro Group. With extensive experience in Legionella remediation, Metro Group immediately took charge, serving as the building’s Legionella-specific consultant. Led by Account Manager, Sal Flores and Water Treatment Product Specialist, Rakesh Budhu, our team compiled the required documentation, mapped the water distribution system, and developed a comprehensive sampling plan within DOH’s tight deadlines.
Legionella Sampling Plan & Results
Metro Group conducted extensive water sampling across all 27 floors, uncovering alarming poor results. 75% of hot water samples tested positive for Legionella. Throughout the process, we coordinated with building representatives, the DOH, and independent auditors, providing clear guidance on the necessary steps.
Acute Remedial Treatment Plan for Water System Decontamination
Metro’s expert recommendation to disinfect the building’s drinking water system involved a powerful two-step process: chlorine dioxide to break down the layers of bacteria-filled biofilm in the pipes, followed by a prescribed dose of chlorine to eliminate any remaining bacteria. This proven approach offers the most effective scientific solution to bacterial fouling in a drinking water system.
In preparation for the remediation, we worked with the building management, who encouraged residents to vacate during the project. We set up portable luxury restrooms, provided backup water for toilet flushing, and coordinated access to all water fixtures.
Following DOH’s directive, we implemented a full-scale decontamination plan as part of our approved ARTP.
Our water technicians worked tirelessly for 34 hours, performing three cycles of chemical treatment throughout the building’s water lines. From Friday morning to Saturday afternoon, we visited every residential unit, commercial space, and school to ensure thorough remediation. This rapid response mitigated the risk and restored the water to standard city water quality.
Here’s a general timeline of how the actual project unfolded:
• Friday 9:00 AM: Metro Group took control of the water system, making it off-limits to residents while chlorine dioxide was introduced to achieve the prescribed dosage.
• Friday 6:00 PM: Proper chemistry levels were verified throughout the building by testing at distal water fixtures. A 3-hour hold time began to allow the chemistry to penetrate the biofilm.
• Friday 11:00 PM: Chlorine was added to achieve the prescribed levels.
• Saturday 5:00 AM: A 3-hour hold time was initiated for chlorine to achieve the maximum contact time for optimal bacteria elimination.
• Saturday 8:00 AM: High-volume flushing and neutralization began to remove biofilm, dead bacteria, and residual chemicals. Access to every water fixture was gained to test and verify that water quality met standard city water parameters.
• Saturday 7:00 PM: The building’s water system was deemed free of contaminants and was returned to the building staff.
The required follow-up sampling will be conducted to assess the effectiveness of the acute remedial treatment plan, and the Long-Term Water Management Plan will be implemented over the next 12 months.
Thanks to Metro Group’s swift action, the building met the DOH’s required timeline. Residents, tenants, and staff can now safely use the water, with a comprehensive plan in place to monitor, test, and respond to any future water quality issues.
How to Prevent Legionella with a Water Management Plan
Legionella bacteria thrive in stagnant or poorly managed water systems. To reduce the risk, proactive measures such as regular water testing, flushing unused lines, and maintaining water temperatures between 120°F–140°F are essential. A customized water management plan provides continuous monitoring and ensures compliance with industry standards. Metro Group can design a tailored plan for your facility, helping you safeguard against Legionella and other waterborne hazards.
Trust Metro Group for Comprehensive Water Management Solutions
Metro Group has been the trusted source for building solutions since 1925. Our team of water experts offer water management plans, testing, maintenance, and decontamination. If Legionella is detected, we respond quickly to contain and remediate the issue, ensuring your building remains compliant.
Contact us today to learn more about our Turnkey Water Management Plans and receive a FREE quote on a comprehensive legionella water analysis from our in-house CDC ELITE & ELAP certified lab.
