10 replies to this topic

[RazM4tt]

I perform quarterly testing on hand sinks in the facility. Normally I see a range of 0-40 APC (our limit is 500 but I prefer to see it under 100). I recently had a sink fail with a TNTC result (too numerous to count) which typically indicates a reading of over 1,000,000. I removed the aerator and tested the water, and it came back 17. Then I sanitized and replaced the aerator and it came back 57. Upon sanitizing the aerator again pulling the sample I got another TNTC result two times in a row. Moving further into the investigation, I pulled another set of samples with the aerator, without the aerator and then directly from the water source under the sink. The results are as follows:

 

With aerator - 5,400

Without aerator - 485

Water Source - 760

 

As you can see there are some inconsistencies but the problem is still identified - water directly from the wall is contaminated.

 

Aside of replacing the aerator and taking the sink out of service, what would your next steps be? I am going to have to communicate with maintenance on how to address this issue and I am trying to get an idea of what resources other facilities use to take care of issues such as this one. Thank you!

 

 

[Slab]

Are you on a well system or municipal supply?

 

You might want to check supply lines for dead legs or potential cross-connections.

[Scampi]

I would be replacing the water line

 

My guess is there is a small hole in the line somewhere large enough to allow infiltration of bacterium 

[RazM4tt]

Are you on a well system or municipal supply?

 

You might want to check supply lines for dead legs or potential cross-connections.

We are on municipal, and all water goes through a softening system before it gets to any production rooms, wash rooms or hand sinks. This specific sink does not get used a lot and it is on the 2nd floor. Im thinking air got into the pipes and there is a dead leg somewhere and it just sat for a long time and developed a film. Im hoping to not replace the pipes and instead just flush with chlorine or something but I dont want to propose ideas to the maintenance team that arent realistic. 

[jfrey123]

Are you able to sample prior to the softening system and then immediately post?  I'm just thinking about every variable here.

[RazM4tt]

Are you able to sample prior to the softening system and then immediately post?  I'm just thinking about every variable here.

I sampled 12 other sinks and they all passed (all less than 40 APC) otherwise I would consider this.

[G M]

We are on municipal, and all water goes through a softening system before it gets to any production rooms, wash rooms or hand sinks. This specific sink does not get used a lot and it is on the 2nd floor. Im thinking air got into the pipes and there is a dead leg somewhere and it just sat for a long time and developed a film. Im hoping to not replace the pipes and instead just flush with chlorine or something but I dont want to propose ideas to the maintenance team that arent realistic. 

 

Have them map the line, if it isn't already, to identify any possible entrapped spaces.  After that you can discuss cutting that section and flushing, possibly in both directions once its separated -- let it sit for an extended period full of a suitable sanitizing agent.  When the flush is done and water back in the line you can monitor for traces of the sanitizer and a return of the problem. 

 

I don't know the resources available to your maintenance team, but that should be relatively easy, if perhaps a little time consuming.  An alternative would be high pressure testing to look for leaks that could be intrusion points, but I would think your normal water pressure would be enough to reveal leaks.  After that I suppose the next alternative is replacing the line.

[UVCautomatic]

I recently joined this community and my background is medical so please forgive my ignorance.

 

We have UVC products that are specifically designed for water supplies, simply goes through a chamber with UVC bulb in it.

Also FAR uvc appliances can be installed above the sink to disinfect the sink.

FAR UVC is not harmful to human under 8 hrs of constant exposures. If you want to sanitize the sink without labor involved, they are easiest products.

 

If you want to know more, contact me

[kingstudruler1]

Aerators are a known micro issue in sinks.    Oddly, I think every water sampling kit ive seen instructs you to remove the aerator, which seems counter productive if you are looking for possible issues.  

 

https://www.scienced...omised patients.

 

I'd start there (maybe leave it our and test daily, etc ).  If that doesnt solve your problem and work your way back to the source as scampi and gm stated.

[ChristinaK]

Did you test for indicator organisms?

Even though the results from that sink deviate from the others sinks sampled, it doesn't necessarily mean the water is unsafe or unsanitary. The microbes are likely harmless if the water still tests negative for indicator organisms or pathogens (fecal coliform, e. coli). 

 

Is this the first time (or several times) that specific sink has been tested? You said you tested 12 other sinks this quarter...is that every sink in the building? Do you remove the aerator when testing those as well? How long do you let the water run before grabbing a sample? Was there a noticeable difference in the water pressure of that sink compared to the others? I only ask because if there's no consistent method to your sampling process, then the data you have is close to worthless.

[RazM4tt]

Did you test for indicator organisms?

Even though the results from that sink deviate from the others sinks sampled, it doesn't necessarily mean the water is unsafe or unsanitary. The microbes are likely harmless if the water still tests negative for indicator organisms or pathogens (fecal coliform, e. coli). 

 

Is this the first time (or several times) that specific sink has been tested? You said you tested 12 other sinks this quarter...is that every sink in the building? Do you remove the aerator when testing those as well? How long do you let the water run before grabbing a sample? Was there a noticeable difference in the water pressure of that sink compared to the others? I only ask because if there's no consistent method to your sampling process, then the data you have is close to worthless.

The procedure is to spray up into the aerator with "approved sanitizer" (we use Alpet D2) and allow to sit for 1 minute. Then we perform a 2 minute flush (allow free flow for 2 minutes with calibrated timer), after which we collect the sample. This was done on all production related hand sinks, washroom water and production room wash water. All results came back passing with 0 pathogenic hits on any of the sites. Here is the panel we test for, with the results of the initial failure site filled in.

 

HPC - TNTC

Coliforms - 0

Ecoli - 0

Staph aureus - 0

Yeast - 0

Mold - 0

Salmonella - 0 

Pseudomonas aeruginosa - 0