How’s the Water in There?

It plays a key role in how well your SPD cleans, sterilizes and maintains your instruments, so you should regularly monitor its various qualities.

The focus in sterile processing is often on processes and technology, but the quality of the water being used in sterile processing departments (SPDs) is all too often overlooked.

Safety hazard

Poor water quality can negatively impact sterilization of your facility’s surgical instruments. It can corrode them or produce deposits, stains or rust. Ultimately, it can delay or even cancel surgeries when OR staff open trays with damaged or unclean instrumentation that is unsafe for use on the patient.

Many surgical facilities simply don’t understand the finer points of water quality or assume they already have the right infrastructure. I’ve visited centers that believe they have water purification equipment, critical water plumbing or water quality monitoring systems in place when they don’t. Because of this limited knowledge, omissions on the part of architects, engineers and designers during the build often go unnoticed until after the fact — if at all. By then, costs to install or deal with the effects of the absence of the needed utilities are much higher, and workflow is impacted or halted.

Bottom line: Unless you’re an expert in water quality or have been suitably educated about what it takes to monitor your supply at your particular facility in your particular area, you could potentially find yourself in a situation that can negatively impact your surgical instruments and equipment, and even your patients.

To maintain appropriate water quality, the first step is admitting you don’t know what you don’t know and getting qualified help to reboot your water management strategy.

New standard

To ensure the adequacy of your SPD’s water supply for cleaning and sterilization, get to know the Association for the Advancement of Medical Instrumentation’s ANSI/AAMI ST108 standard, “Water for the processing of medical devices,” or find someone like me who is intimately familiar with it. Published in August 2023, this standard revises and replaces AAMI TIR34:2014/(R)2021, which was previously in wide use but only provided recommendations as opposed to this new evidence-based consensus standard.

ST108 covers quite a lot of ground. It defines categories of water quality that should be used during each stage of sterile processing, provides risk analysis insight and assesses water quality based on a variety of factors. It also details maintenance, monitoring and quality improvement procedures for your water treatment system and informs you on what actions to take during service interruptions and boil water advisories.

Of course, you’re a healthcare provider or executive, not a water quality expert. If you feel lost in the weeds on ST108 or unsure about water at your facility, third-party consultants like me can help. All we do is think about H2O.

Types of water

FULL SUBMERSION The water used for endoscope reprocessing can’t be tap water; it must be treated prior to its use in the sterile processing department.

Typically, surgery centers should have ample supply of three types of water.

• Utility water. This is tap water from your local municipal supply that can be used for initial rinsing of instruments and other general purposes.

• Critical water. This type is filtered and processed in your facility to meet ST108’s purity requirements. Critical water is necessary for proper final rinsing of instruments to remove all residual materials and ensure instruments are as clean as possible. If they aren’t clean, they can’t be sterilized completely. Critical water should run through plastic or stainless steel piping as opposed to copper to avoid shedding of metal ions into the supply.

To produce critical water, surgery centers need a reverse osmosis or reverse osmosis/deionization system, which usually includes a water softener, ion exchange columns and a storage tank, because production of critical water usually can’t keep up with instantaneous usage levels. Using these systems, utility water should be circulated through a loop that includes an ultraviolet disinfector. Disinfected critical water travels to the SPD and any other designated points of use, then returns to pass again through the loop.

Steam. ST108 also defines the purity levels for steam used in sterilization. Ideally, steam is made from critical water in stainless-steel boilers if the boilers are built into the sterilizers. For iron or steel boilers, softened water is a good answer that reduces the buildup of residual contaminants in the boiler. Note that steam generated from softened water may not meet all of the requirements of either ST108 and AAMI ST79 for purity and steam quality, but it is a great improvement over tap water feeds.

Key metrics

To avoid filming, rusting and staining, these are aspects of your center’s water supply you should regularly monitor and adjust to extend the lifespan of your surgical instruments.

• Particulates. Too many facilities do not adequately protect themselves from the vagaries of their municipal water supply. I had a client whose facility was located in a high snow area. Once the snow started melting in the spring, there was a big uptick in microparticulates and mineral content dissolving in the ground on the way to the water table and then to the municipal supply. The water would be very clean in summer, horrible in spring due to the runoff, and great in fall and winter when the water table was rather clean.

To maintain appropriate water quality, the first step is admitting you don’t know what you don’t know.

Coarse filtration such as sand filters or other particulate filters can remove this variability by bringing your water’s level of particulates down to the preferable five or 10 microns no matter what time of year it is, but their utility goes beyond seasonal concerns. For example, consider a water main break in your area. After the utility company fixes the break and turns the water back on, everything that’s been sitting quietly at the bottom of the municipal piping for however many years flows right into your facility. These types of filters ensure the great majority of these materials never make it to your SPD. Without these filters, you’re not protecting yourself from changes in the municipal water supply.

• Hardness. The AAMI limit from ST108 for water hardness is 150 milligrams per liter, a good working number. If it goes above that, you’ll start seeing lime encrustation on instruments. Water softening is crucial for effective instrument reprocessing.

• Chloride. Watch out for chloride. You want to try to get it to a reasonably low level, because this mineral will eat stainless steel for breakfast, lunch and dinner. When water has a high chloride level, the resulting corrosion can turn nice, shiny instruments into rust buckets. The chloride limit in ST108 is 250 milligrams per liter, which comes from EPA drinking water standards. I think a more reasonable limit is 100 milligrams per liter. Most facilities can meet this number, but it can be an issue in certain areas of the country.

The only solution to mitigate elevated chloride levels in your water, unfortunately, is to mix critical water with your utility water and then pump it through the plumbing. This requires a fair amount of infrastructure, particularly a mixing tank and high-capacity pumps.

• pH level. This is commonly not a problem. The pH level of utility water usually ranges from about 7 to 9, while your critical water supply should have a pH level between 5 and 7.5. As long as the utility water is not below pH 7, there should be no issues, but softened, low-pH water might start to cause trouble with copper piping.

• Total dissolved solids. This is usually measured using conductivity as a proxy, which is an easy measurement you can do in seconds rather than sending samples to a lab. If you’re above 500 microSiemens per centimeter, you’ll start to see deposits on sinks, washers and instruments. These won’t present like water hardness deposits do, and a high level of total dissolved solids especially can foul boilers for steam generation, hinder the smooth operation of instruments with sliding parts or hinges, and may lead to staining or corrosion.

Surgery centers tend to have dedicated boilers either on-board their sterilizers or close to their sterilizers. A high level of total dissolved solids will increase the maintenance frequency of the boilers. The only way to deal with it is to admix critical water to reach a compliant level.

Measure and monitor

REMOVE THE MYSTERY How safe is the water that’s piped into your sterile processing department for your instruments and patients? If you don’t know, it’s easy to find out.  |  Northwell Health

Ensuring your water quality is suitable for reprocessing isn’t a set-it-and-forget-it proposition. It requires regular, consistent monitoring because conditions change and evolve both internally and externally to your center. You need to keep an eye on it and know how to correct problems.

ST108’s Table 6 provides a minimum monitoring schedule. For example, you should monitor the conductivity of your critical water continuously. Normally, conductivity monitors will be built into your water processing system so you’ll have that continuous measurement, which is best practice. These systems will alarm if things go bad. Alarms, by the way, should not just be in the water utility room. They must be visible or audible outside that room so people are informed that there is an issue in a timely manner.

For critical water, testing should be no less frequent than monthly. It’s the last water that touches the instrument before sterilization and removes almost all residual contaminants.

Semicritical items that are not sterilized should not be contaminated with bacteria or endotoxins, the presence of which could conceivably cause surgical site infections (SSIs) or morbidity.

ST108 provides ranges that have safety margins. If your water is within those ranges, you very likely won’t have a situation where an SSI could result from your water supply. You can bet that a lawyer will ask if you can prove that your water supply did not cause an SSI in their client. In response, you should be able to show them that, on a monthly basis, your water has no appreciable amount of bacteria or endotoxins.

The tests and monitoring required for water quality assessment aren’t free, but they’re not expensive either. We’re talking an annual budget of about $5,000 for this, which is much less costly than a huge settlement of an SSI case or cancelled surgeries. You can buy a lot of the testing equipment for very little expense, but you need to know which tests you need to perform and how to perform and document them correctly. Once you know what you need, the self-testing is not hard to do.

ST108 requires that your facility have a water management committee that includes leadership, facilities engineering (in-house or third-party), infection prevention, sterile processing, clinical engineering (whoever maintains equipment such as your sterilizers and washers, for example), a representative from the surgical department and a water treatment specialist (like me). This committee is tasked with ensuring that the water delivered to point-of-use meets established quality requirements.

It’s a good idea to have a water expert visit once a year to perform an independent assessment of your center’s water quality through lab analysis and system review. Once you get a good-to-go response from that annual audit, you can follow the ST108 monthly and quarterly monitoring schedules yourself. But if things go wrong, have someone available to call on to demystify the situation for you.

Water consultants aren’t cheap, but used judiciously, they’re good insurance. If all you know is that you are having problems with corrosion, with deposits, with articulated instruments that feel like they have gravel on them, you don’t need to become a water chemist. You’re supposed to be providing medical care. It is critical to have somebody who will pick up the phone, not charge you an arm and a leg, and give you informed advice and insight to defend your center against potential issues.

Don’t drown in water problems

Water issues can shut down your facility, and that’s really what this comes down to. Sometimes you get lucky, and there’s a smoking gun to pinpoint your problem — a piece of equipment isn’t working, or you don’t have the right filter. Sometimes, though, it’s death by a thousand cuts, and you need someone who can identify and investigate each of those cuts to fix the problem.

If you’d prefer not to shut down surgeries or procedures because of a water problem, it’s worth the expense. OSM