Cleaning raw water tanks for Renal plant

[Chris Bates]

Hi,
Our trust water safety group is looking at the cleaning and disinfection of the raw water tanks for all our water plants.
Do any renal techs out there do this, or is it normally an estates issue?

I did have to stop an estates contractor a few years ago when they wanted to use silver stabilised peroxide to disinfect a tank - this was blamed for a death and serious injuries in one dialysis unit a few years ago.

Chris

[fraser gilmour]

Hi Chris,
did they give any reason why they would see this as beneficial for a renal application? Are they just applying the principles for hospital water safety generally, without an understanding of how we use water in renal?
What quality of water are they trying to achieve at this point in the system and why? how often are they planning to do this disinfection? why stop at the tank and not all the pipework up to the RO?
So many questions, but to answer yours, no we haven't ever done regular disinfection of our break tanks.
There will be an elevated micro level at this point, higher still after carbon stage and then filtered out by RO. I suppose the micro levels will vary across the country depending on mains water conditions, and that should influence RO disinfection regime.
hopefully see you next week  
 

[Chris Pearson]

Won't the raw tanks have trace levels of bleach in them keeping biofilm down ?

[fraser gilmour]

The incoming water will have a residual chlorine level but bacteria will try to colonise the tank surface and develop a protective biofilm layer regardless.

[Chris Pearson]

https://ccforum.biomedcentral.com/articles/10.1186/cc8158

[Garry]

Performed by our estates department in line with the other tanks on the roof.

I've asked multiple times for use to be made aware when this happens so we can apply enhanced monitoring if required.

In conjunction with our water management group,  we've also offered to input to a specific renal water escalation process should anything affect potable water to the building.

[fraser gilmour]

By coincidence I had raised a query with our municipal water provider at one unit where we had seen abnormally low residual chloramine levels on the incoming, down to 0.03mg/L.
They came out to investigate and were not concerned about the low chlorine levels, but offered to take bacteriology samples from before and after the tank anyway.
Incoming was slightly above 100cfu/ml and post tank was less, 56cfu/ml at 22 degrees and 19 at 37 degrees after two days. Ecoli was negative.
They didn't disinfect the run off point for fear of putting disinfectant into the live system, so we might have picked up some growth in from the tap, but they reported the results were still in line with what they would expect for a tank with high turnover.