Legionella Control Water Treatment Comparison Chart

Technology Comparison for Domestic Hot Water Treatment Methods to demonstrate why Copper Silver Ionisation should be your #1 long-term Legionella control and prevention choice.
The following is a water treatment comparison chart on chlorine dioxide (ClO2), chlorine (Cl2), ozone (O3), thermal eradication and copper silver (Cu-Ag) ionisation for Legionella control and prevention in domestic hot water systems. These domestic hot water systems are normally found in healthcare facilities, hotels, nursing homes and other large buildings.
The information presented is as accurate and factual as possible based on available data and field research.

	Cl2 Chlorine	ClO2 Chlorine Dioxide	O3 Ozone	UV Ultra Violet	High Temp Eradication	AquaLyse® (Industrial) Cu/Ag Ion
Biofilm Penetration	No (not 100%)	Yes (ClO2 Takes over 17 months)	No	No	Yes/No (difficult to get 100% penetration)	Yes at 100% (Saturation in under 4 hours)
Startup cost (Approx.) For 100M3 \| 25,000 GPD of domestic hot water:	$6,000 plus labour per application. Must be repeated every 3 to 6 weeks.	$55,000 plus installation, calibration and distal point water bleeding.	Not suitable for domestic hot water system.	Not suitable for domestic hot water system.	Labour requirements for water systems distal point water bleeding.	$17,447.00 plus installation and calibration. No water flushing required.
Yearly maintenance and replacement / replenishment costs for 100M3 \| 25,000 GPD of domestic hot water:	$40,000 to $70,000 plus approximately $175,000 for ongoing maintenance labour and water testing protocols. Must be re-applied ever 3 to 6 weeks in combination with distal water bleeds.	$15,000 per year in on-going chemical and cartridge costs alone. SodiumChlorite (NaCLO2): $4,000 to $8,000 for the drums. Then $3,000 to $8,000 per year for cartridges. Plus corrosion related replacement parts.	Not suitable for domestic hot water system. Ozone will not stay soluble.	Not suitable for domestic hot water system.	Must be re-applied ever 3 to 6 weeks in combination with distal water bleeds. Approx $225,000 for ongoing maintenance , labour, energy usage and water monitoring. Provokes accelerated corrosion.	$3,475 per year in on-going copper and silver electrode replacement
	Cl2 Chlorine	ClO2 Chlorine Dioxide	O3 Ozone	UV Ultra Violet	High Temp Eradication	AquaLyse® (Industrial) Cu/Ag Ion
Cost over 10 years to treat 100M3 \| 25,000 GPD of domestic hot water:	Between $500,000 and $2,000,000 with sever corrosion damage	Between $150,000 and $250,000 with corrosion damage.	Not suitable for domestic hot water system.	Not suitable for domestic hot water system.	Between $500,000 and $2,000,000 with accelerated corrosion damage.	Between $35,000 and $75,000.
Saturation Time required for open water loop	Time is proportional to concentration levels and distal water bleeding.	Time is proportional to concentration levels and distal water bleeding. Full distal point and dead-leg saturation in 17 months + No distal bleeding requirements.	O3 cannot reach distal points in domestic hot water systems due to solubility issues.	UV is a nonsystematic technology	time is proportional to maintained temperature and distal water bleeding.	Industrial Copper SIlver units take only minutes to saturate the water loop. Full distal point and dead-leg saturation in less than 45 days No distal bleeding requirements.
Systemic Biocide Properties (does it treat all of the water system including distal low flow areas and dead legs?)	No	No	No	No	No	Yes
Dangerous byproducts or side effects:	Yes THM carcinogenic	Yes Chlorites Chlorates Halogens	Yes Perchlorate and Bromate	No	Yes (Scalding) accelerated corrosion when combined with Cl2	No
	Cl2 Chlorine	ClO2 Chlorine Dioxide	O3 Ozone	UV Ultra Violet	High Temp Eradication	AquaLyse® (Industrial) Cu/Ag Ion
Corrosive facts when in domestic hot water systems.	Yes especially when introduces in domestic hot water systems.	Mechanical failure of technology pumps and on-going replacement of fender pumps.	Yes it is an oxidant yet solubility is more of an issue with this technology when used in domestic hot water systems.	No U.V. light causes genetic mutations and thus stops the microbiological reproductive process. It does not treat the biofilm where bacteria is normally protected and thrive.	Yes can accelerate the corrosion process.	No does not corrode (oxydate) by any means.
Operational system temperatures	No limitations.	No direct limitations. Some distal solubility issues in hot water loop dispersion.	Not suitable for domestic hot water system. Solubility issues in water loop dispersion.	Not applicable	Not applicable	No limitations. Excellent for cold and/or hot water applications.
Water pressures	Not applicable	40PSI.	Not applicable	Not applicable	Not applicable	AquaLyse® systems can operate in water pressures of up to 750 PSI


UK	CA	IT	USA

Biofilm Penetration

Saturation Time required for open water loop

Biofilm
Penetration

Saturation
Time required
for open water loop