How the Orca system compares
Unlike any other technique, the Orca system destroys biofilm; a slimy layer that rapidly forms on the inner side of pipework. Biofilm should be a concern because Legionella bacteria multiple to high levels in it and hide away from chemicals and heat that do not penetrate it. Complete water systems become colonised by Legionella bacteria from biofilms. Biofilm is the biggest source of Legionella bacteria.
Unlike UV, ultrasound, filtration, and chemical treatment that have a very short term residual effect, the Orca system has a long term residual effect and will remain actively fighting bacteria not only over distance but also for a long time. It has proven to have been effective for months even when the system was turned off.
Unlike UV, ultrasound, filtration which are only effective at the place of contact, the Orca system can destroy Legionella even in stagnant water because the copper and silver ions are active until they are ‘consumed’.
The Orca system has been proven to even penetrate deadlegs of 3 metres long and penetrates not only biofilm but any other material that can reduce the diameter of pipes.
Indeed, copper and silver ionisation out-competes its rivals across the board. As documented in the chart below:
Parameters |
Copper and Silver Ionisation |
Continuous Chlorination |
Heat and Flush |
Chlorine Dioxide |
Ultra Violet Light (U.V.) |
| Concentration required at outlets | Cu = 0.2 - 0.8 mg/l Ag = 0.02 - 0.08 mg/l |
2 - 4 mg/l as free chlorine |
80°C for 30 min |
0.5 - 1 mg/l as CLO2 |
300 nm |
| On-site efficacy documented in literature | Yes |
Yes |
Yes |
Yes |
Yes |
| Residual effect | Yes |
No |
No |
More stable than Chlorine |
No |
| Time to re-colonization | 6 - 12 weeks |
1 - 2 weeks |
Varies |
No information available |
Only works at point of entry |
| Temperature | Residuals uneffected by high temperature |
Residuals decrease as temperature increases |
NA |
Residuals decrease as temperature increases |
Only works at point of entry |
| pH | Elevated pH (>8.5) may affect efficacy |
Elevated pH (>8.5) affect efficacy |
No effect |
No effect |
No effect |
| Disinfection by-product | None known |
Trihalomethane (THMs) |
None |
Chlorate and Chlorite |
None |
Taste and odors |
None |
Yes |
No |
Minimal at high concentrations |
None |
Pipe corrosion |
Non observed |
Highly corrosive |
Old pipe may be affected |
Corrosive |
None |
Maintenance issues |
Routine ion monitoring Routine inspection of electrodes |
COSHH Applies Concentration control and monitoring Corrosion control |
Scalding possible Labour intensive |
COSHH Applies Concentration control and monitoring Corrosion control |
Routine cleaning |
Efficacy issues |
None |
Does not penetrate biofilm Loses efficacy at elevated pH. Decays at elevated temperature and over distance |
Does not penetrate biofilm Legionella bacteria only lay dormant below 20°C and above 60°C |
Decays at elevated temperature and over distance |
Can only be effective at point of entry Does not work with shadows |