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Deposition control: the pre-emptive strike against legionella. August 12, 2013. The Problem with Legionella. Only pathogen that enters the facility only through the water system Occurs naturally in water, but not managed by the water utility – 3000x more resistant to free chlorine
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Deposition control: the pre-emptive strike against legionella August 12, 2013
The Problem with Legionella • Only pathogen that enters the facility only through the water system • Occurs naturally in water, but not managed by the water utility – 3000x more resistant to free chlorine • Thrives in water system surface deposits – • Sloughing off -> outbreaks • Remove deposits & biofilms to limit • risk of growth & spread of legionella • How Legionella Subverts to Survive, • Medical Xpress News
Why Address The Problem Now? • Only way to stop a legionella outbreak is to prevent it – May not be legionella in your water system, but biofilms that harbor it are. • 7 – 10 day incubation data • Codes & standards mandate it • The Joint Commission & ASHRAE 188 • Maryland Department of Health & Mental Hygiene report recommends routine sampling for legionella in healthcare water systems
Methods of Legionella Control Thermal Remediation Super/Hyper Chlorination Chlorine Dioxide Copper Silver Chlorination & Deposit Control* Periodic, temporary solutions Continuous, but limited effectiveness & expensive Continuous, long-term, inexpensive
Chlorination & Deposit Control* • Chlorination Method (0.2–2 ppm Free Cl): • Use of incoming free chlorine residual • Augment residual with sodium hypochlorite • Deposit Control Method: • Clearitas 301 or Clearitas350 • Stable, patented product of an advanced oxidation chlor-alkali process • Only solution to address underlying biofilm build up • Disrupts internal deposit bonding mechanisms
Case Study: Medical Building • Case study performed by hospital’s third party engineering consultant • Consistent Legionella problem at Facility • Quarterly remediation required (Thermal) • Chlorine dioxide used in half of test building (not in case study water system) • Incoming from City: 0.2-0.3 ppm Free Cl
Methods of Study • Deposit control is injected into the incoming city water line • Deposit control is proportionally fed • Domestic cold and recirculating hot water systems. • 23 distal points measured for environmental changes • Sampling based on Mil Standard 105E 95% confidence chart • Baseline sampling for 4 weeks • 8 additional sampling periods over increasing time span (4 weeks) • Objective: to measure the impact on water quality and effectiveness of legionella control
Residuals and Legionella (Hot Water Loop) System Disruption High deposit control dose @ 500 ppm 0.45 ppm free Cl from deposit control
Water Quality Impact Summary Note: the data from sample period four was disregarded due to the system disruption
Conclusions • Clearitas deposition control does NOT: • Dissolve deposits (it disintegrates them) • Adversely affect water quality • Clearitas deposition control does: • Facilitate legionella control • Attack organic components of deposits • Actively inhibit future growth of legionella • Reduce chlorine demand • Take a pre-emptive strike & address legionella before it becomes a nightmare.
Thank You For additional information: Web: www.BlueEarthLabs.com Email: Ben.Santoli@BlueEarthLabs.com Phone: Resources: