Sample Disinfection Protocol

By Greg Reyneke

October 19, 2009

Sample Disinfection Protocol
Every location is different, with varying water-usage patterns and expectations of water quality. The annual service and disinfection model is clearly deficient, so service intervals should be based upon the aggregate amount of hardness and other inorganics processed by the system. Many industry experts agree that a system should be serviced and completely disinfected after processing approximately 1,000,000 grains or at least every 12 months, whichever is sooner. Disinfection frequency should be increased if there is any suspicion that the influent water supply is not microbiologically safe.
Industry standard employee safety precautions should always be taken before implementing this or any other disinfection protocol.

While every possible effort has been made to ensure the efficacy of this protocol, you are still ultimately responsible for the microbiological safety of the equipment in your facility and you should completely familiarize yourself with the advantages, disadvantages and liabilities of this or any other protocol before applying it. Proceed with caution at your own risk.

Disinfection of Contaminated Water Treatment Equipment
Quantities, types and concentrations as per manufacturer’s instructions

Chemicals required
Anionic Surfactant concentrate
Detergent
EDTA
Deionized Water
Concentrated Biodegradable Disinfectant

Tools required
Appropriate protective equipment (eye protection, respirator, gloves)
Mechanical scrubbing apparatus
Approved waste disposal materials

Procedure

o Discard all salt from regenerant tank in an environmentally friendly manner
o Disconnect regenerant tank & scrub until clean with detergent until residue is removed
o Rinse detergent from regenerant tank in an appropriate manner with clean water
o Apply concentrated detergent to all contact surfaces in regenerant tank
o Allow detergent to remain in contact with regenerant tank for at least 20 minutes
o Rinse regenerant tank with clean water
o Replace all regenerant tank tubing and fittings and reconnect to system
o Safely bypass and depressurize water treatment system
o Open pressure vessel and inspect for evidence of bacterial overgrowth
 If evidence of overgrowth is found, all media should be discarded
o Reassemble pressure vessel and pressurize with clean water
o Surfactant Injection
 Mix surfactant and deionized water to appropriate concentration & volume
 Educt 4 bed volumes of surfactant solution into pressure vessel
 Allow 10 minutes of contact time
 Rinse at least 8 bed volumes or until no surfactant residual remains
o EDTA Injection
 Educt 0.5 bed volume of EDTA into pressure vessel
 Allow 5 minutes of contact time
 Rinse at least 4 bed volumes or until no EDTA residual remains
o Disinfectant Injection
 Mix disinfectant and deionized water to appropriate concentration & volume
 Educt 2 bed volumes of disinfectant solution into pressure vessel
 Allow 60 minutes of contact time
 Rinse at least 4 bed volumes or until no disinfectant residual remains
o Testing and evaluation
 Swab inside of regenerant tank and culture as per instructions
 Draw sample of effluent water and culture as per instructions

Periodic Disinfection Procedure

Quantities, types and concentrations as per manufacturer’s instructions

Chemicals required
Anionic Surfactant concentrate
Detergent
EDTA
Deionized Water
Concentrated Biodegradable Disinfectant

Tools required
Appropriate protective equipment
Mixing apparatus

Procedure

o Surfactant Injection
 Mix surfactant and deionized water to appropriate concentration & volume
 Educt 0.1 bed volumes of surfactant solution into pressure vessel
 Allow 5 minutes of contact time
 Rinse at least 2 bed volumes or until no surfactant residual remains
o EDTA Injection
 Educt 0.1 bed volume of EDTA into pressure vessel
 Allow 5 minutes of contact time
 Rinse at least 2 bed volumes or until no EDTA residual remains
o Disinfectant Injection
 Mix disinfectant and deionized water to appropriate concentration & volume
 Educt 0.25 bed volumes of disinfectant solution into pressure vessel
 Allow 10 minutes of contact time
 Rinse at least 2 bed volumes or until no disinfectant residual remains
o Prophylactic application of disinfectant
 Mix disinfectant and deionized water to appropriate concentration & volume
 Add disinfectant solution directly to regenerant tank
 Initiate delayed regeneration/cleaning of water treatment equipment

NOTE – Surfactant, EDTA, and Disinfectant can be blended together to improve on-site efficiency if performed within manufacturer’s specifications and according to industry best-practices.

Greg Reyneke · Greg Knows Water

Water Quality Improvement Professional