7 replies to this topic

[NicoD]

Hello everyone,

 

so we tested the tap water as every year. Total aerobic flora, coliforms, and E.coli.

 

Everything was great (<1 CFU/mL for the total and <1 CFU/100mL for the 2 indicators), except for 1 large sink in the processing room.

The other sink (small one) in the same room is fine. This one is not, and it's a newly installed one:

 

Total aerobic count: 125 CFU/mL

Coliforms: 58 CFU/100mL

E. coli: <1 CFU/100mL

 

What do we do in your opinion?

 

Thanks.

[FurFarmandFork]

Assuming you properly sanitized and flushed the outlet (removed screen from faucet etc.) and there wasn't a sampling error, my assumption would be that the lines were contaminated during installation. Perhaps test the water coming out of the wall connection before it passes through the sink, that would help you know if the contamination came from the water itself or from the sink.

 

IBWA has a coliform retesting procedure for bottled water that would be somewhat valid for you to use in your follow up testing:

 

If positive for total coliform, an E. coli determination is performed from that test. When a unit of production results in a positive result for coliform organisms by a total coliform method in Standard Methods for the Examination of Water and Wastewater, 20th Edition, the following policy and procedure should be employed:

 

1. Immediately analyze 10 additional samples from the same production lot for total coliform. Also examine the original sample for presence of Escherichia coli (E. coli) by a method in Standard Methods, 20th Edition.

 

2. Review sampling and analytical procedures to determine if the original sample contamination may have occurred due to sampling or laboratory error. If the review of sampling and analytical procedures demonstrates a source of contamination, such as contaminated media or analyst error, INVALIDATE results and proceed with total coliform analysis of five additional samples from the same lot using uncontaminated media and proper technique.

 

3. Company plant personnel should use the following guidelines for decisions on the disposition of the lot: a. If the re-sampling does not show E. coli or total coliform, consider the first sample an invalid result. b. If the original sample AND any of the additional four samples collected are positive for total coliforms or E. coli, consider the results valid and conduct follow up actions pursuant to the company’s plan.

 

http://www.bottledwa...212_FINAL_0.pdf

 

 

If it is contamination at the sink, then you could somehow plumb the fittings up to some pressurized sanitizer and essentially CIP the internal components (chlorine would work well since presumably the sink's materials should be somewhat resistant). Alternatively it may be easier/cheaper to just replace the faucet and fittings on the sink. Then talk about handling them in a sanitary manner with your maintenance crew, who may have done the drain plumbing first then worked with the water connections without a hand wash in between.

[Charles.C]

Hello everyone,

 

so we tested the tap water as every year. Total aerobic flora, coliforms, and E.coli.

 

Everything was great (<1 CFU/mL for the total and <1 CFU/100mL for the 2 indicators), except for 1 large sink in the processing room.

The other sink (small one) in the same room is fine. This one is not, and it's a newly installed one:

 

Total aerobic count: 125 CFU/mL

Coliforms: 58 CFU/100mL

E. coli: <1 CFU/100mL

 

What do we do in your opinion?

 

Thanks.

 

Hi Nico,

 

I hope yr post is not based on results for one sample of each sink ?.

 

BTW, what is the free chlorine level in the water ?

[NicoD]

Assuming you properly sanitized and flushed the outlet (removed screen from faucet etc.) and there wasn't a sampling error, my assumption would be that the lines were contaminated during installation. Perhaps test the water coming out of the wall connection before it passes through the sink, that would help you know if the contamination came from the water itself or from the sink.

 

IBWA has a coliform retesting procedure for bottled water that would be somewhat valid for you to use in your follow up testing:

 

 

If it is contamination at the sink, then you could somehow plumb the fittings up to some pressurized sanitizer and essentially CIP the internal components (chlorine would work well since presumably the sink's materials should be somewhat resistant). Alternatively it may be easier/cheaper to just replace the faucet and fittings on the sink. Then talk about handling them in a sanitary manner with your maintenance crew, who may have done the drain plumbing first then worked with the water connections without a hand wash in between.

 

Thanks so much FurFarmandFork! Wonderfully thorough!!

 

 

Hi Nico,

 

I hope yr post is not based on results for one sample of each sink ?.

 

BTW, what is the free chlorine level in the water ?

 

Hi Charles, thanks so much. Good question the second! I don't know.

 

About the first question, well, I wish I could double- or triple- test things.

 

I made sure, however, the sampler let water run for 2 minutes and collect it aseptically in the ready sterile bottles. 2 x 100mL bottles, then mixed aseptically by the testing lab.

 

Thanks.

[Charles.C]

Thanks so much FurFarmandFork! Wonderfully thorough!!

 

 

 

Hi Charles, thanks so much. Good question the second! I don't know.

 

About the first question, well, I wish I could double- or triple- test things.

 

I made sure, however, the sampler let water run for 2 minutes and collect it aseptically in the ready sterile bottles. 2 x 100mL bottles, then mixed aseptically by the testing lab.

 

Thanks.

 

Hi Nico,

 

A detectable free chlorine level would suggest yr sample/data for the new sink might be "atypical".

[sqflady]

Did you sanitize the outlet before taking the sample?  I use a torch to "heat" sanitize the faucet outlet before taking samples.  Then continue your procedure of letting water run for 2 minutes and collect aseptically.  

[NicoD]

Did you sanitize the outlet before taking the sample?  I use a torch to "heat" sanitize the faucet outlet before taking samples.  Then continue your procedure of letting water run for 2 minutes and collect aseptically.  

 

Thanks sqflady.

I used to spray 91% isopropyl alcohol thoroughly all over the faucet in the past, before running the water.

However, I then realized that it's not the normal use of the station. I thought the purpose of water testing is to test the system entirely, from the water source to the faucet. So, if for any reason normal processing contaminates the faucet, I need to know.

 

I might know what you're thinking now: I should have taken at least double samples: before and after sanitizing the faucet, if I wanted to assess/isolate problems!

[FurFarmandFork]

Thanks sqflady.

I used to spray 91% isopropyl alcohol thoroughly all over the faucet in the past, before running the water.

However, I then realized that it's not the normal use of the station. I thought the purpose of water testing is to test the system entirely, from the water source to the faucet. So, if for any reason normal processing contaminates the faucet, I need to know.

 

I might know what you're thinking now: I should have taken at least double samples: before and after sanitizing the faucet, if I wanted to assess/isolate problems!

In water land we call that "first draw" testing, often done for things like lead to make sure that if they are leaching into standing water that we get the levels someone is likely to drink.

 

I appreciate your realistic view of your EMP. It's bold and I hope you can handle the corrective actions it may generate, definitely a thorough approach though!