Given the recent events on Florida’s Gulf Coast, thanks to Hurricane Ian, and other water supply issues in Jackson, Mississippi, and even Baltimore, it’s time for me to climb down from the ivory tower of scientific purity and get my hands dirty and feet wet like we all have to do when things like this happen.
What happens to the water supply when any of those items in the title happen? Water treatment facilities can’t keep up and:
It probably doesn’t meet the EPA drinking water standards, which means that if you are using municipal water as utility water for instrument processing, stop now.
- The bacterial loading goes up. A lot. Which has obvious issues relative to safety and, if you run the load through a washer-disinfector, may result in high endotoxin levels from thermal disinfection.
- The particulate level goes up. A lot. A client of mine had $5 million in instruments destroyed following three water-main breaks due to the particulates being stirred up from the bottom of the water main when the breaks were repaired and the water supply reestablished.
- If chemical shocking is used to get bacterial loading down and make the water safer to drink or bathe in, the residual chemicals may destroy your softeners, RO, or DI systems.
What can you do? Boiling water in response to bacterial issues is adequate for minimal home use to inactivate bacteria, but how are you going to do that on the scale needed for SPD volumes of water consumption? You can’t.
There are two answers here: one is in response to the emergent situation when a natural disaster takes place; the other is a planned preparation so that your work can continue when needed most with little impact on SPD operations.
Emergency!
In this case, any and every part of the water system is suspect and should be treated as a source of infectious agents. Rinsing instruments with purchased sterile water with thorough agitation and operation if there are moving parts after normal processing prior to prep and pack is a necessity. This will help to remove any bacterial residue and endotoxin.
But if the water is turbid, cloudy, and disgusting when it comes into the decontam sinks and other visible points of use, how can you possibly clean things in that disgusting water? You can’t. You need to get water that has been purified to some extent trucked in or otherwise supplied to keep the processing going.
In the meantime, it’s time to order some filters to protect the water supply. More about that in the next section.
After the boil-water alert is rescinded, here’s what you have to do with your water supply system in the building:
Utility Water
- Flush the building water supply system with chlorine disinfectant.
- Ensure that chlorine is detected at the farthest point of use from the point in which the chlorine is introduced.
- After the disinfectant application is complete—and it should be done at least twice, possibly three times—flush until residual chlorine is no longer detected at the feed water source or at the farthest point of use.
- Test for bacterial contamination. If it is below the allowed levels (500 CFU/ml for bacteria), you are back in business. If not, disinfect again until below this level and preferably near your historical average level.
Critical Water
- Get the utility water back to a good state using the procedure shown above.
- Flush the critical water feedwater supply system with chlorine disinfectant.
- Once chlorine is detected, flush the feedwater source to drain.
- After the disinfectant application is complete—and it should be done at least twice, possibly three times—flush until residual disinfectant is no longer detected at the entry to the critical water generation system.
- Drain, disinfect, flush, and refill the water storage tank.
- Change pretreatment filters, backwash carbon tanks, regenerate the softener, and clean and disinfect the distribution loop using chlorine.
- If chlorine is not detected at points of use off the distribution loop, it has been used up already. Repeated chlorine disinfection is required until chlorine is detected at all points of use.
- Rinse the system until chlorine is no longer detected at any point of use.
- Replace the loop final filter.
- Ensure any disinfection lamp’s plumbing is not obstructed with biofilm or its remainders.
- Change out any deionization tanks.
- Replace the loop’s final filter.
- Test for bacterial contamination. If it is below the allowed levels (10 CFU/ml and 10 EU/ml for bacteria and endotoxin, respectively), you are back in business. If not, repeat the cleanout and disinfection until below this level and preferably near your historical average level.
Be prepared
Most healthcare facilities in which I have consulted place entirely too much trust in the municipal water supply for their utility water supply. You shouldn’t. What you should do is practice safe water delivery, which means:
- Provide protective initial filtration of the water supply as soon as it enters the building. This is done most inexpensively and effectively with sand filters, which use sand to filter water. You can get different sand grades to get different levels of filtration based on particle size. It is probably best to have a rough filter first to get the larger particles out, followed by a finer filter to get smaller particles (fines) out. These would be around 25 microns for the rough filter and two to five microns for the fines filter. If there is no desire to do this on a large scale for the entire facility, it should at least be done for SPD’s water supply.
- Okay, the particulates are taken care of, but E. coli is a rod-shaped bacterium about two microns long and one micron in diameter for the rod (i.e., probably smaller than your fines filter’s pore size rating). How do we stop it? With a smaller filter. Once the large particulates are gone, you don’t have to worry (as much) about clogging fine-pore filters with particulates. You can go after known, problematic bacteria with a filter of, say, 0.5 micron. Or go for ultrafiltration. This last option is not absolutely necessary, but it is available and has the advantage that it can be set up to automate filter backwash. The critical issue in any attempt to capture bacteria is to ensure that the filter is changed regularly and the filter housing and plumbing are cleaned and disinfected when the filter is changed to avoid creating a biofilm-based factory for bacteria and endotoxins.
- The water generated in a system like this will provide a good start for generating critical water. Since most fines filters don’t get along well with hot water above 125°F, you may need to generate hot water after the filtration station. The good news is that you only need one filter system if you use the same supply for cold and hot water.
Natural disasters are projected by some to increase in the coming years. Maybe yes, maybe no. Water systems issues will increase in direct proportion to the number of natural disasters. If they do or if they don’t increase, they will still happen. In the SPD, we should always consider the worst case possible to protect our ability to help save lives in healthcare. This means prepare for the worst and maintain the system to ensure that those preparations are not wasted.