If your facility has a stagnant water system and needs to be re-opened, there are some key considerations when handling the process. This will help to prevent the spread of microorganisms and bacteria. Once you have completed these steps, you will be able to safely restart operations and continue with day-to-day business as usual.
Consequences Of Not Handling Stagnant Water In Plumbing Systems Properly
If stagnant water is not removed from plumbing systems regularly, it can lead to a range of problems, including mold and mildew growth, clogged drains, and even bacterial or viral infections.
Microbiological growth, heavy metal leaching, and corrosion may occur in our plumbing systems after many weeks of zero flow, low flow, and tempered water.
Understandably, company owners and government officials will welcome a return to routine a few months following a facility’s”reopening.” When restoring inactive buildings with sluggish water systems, however, new and unexpected problems may arise.
It Is Critical To Plan Ahead Of The Reopening
Let’s take a close look at steps building facility managers should consider in order to maintain water quality and safety in plumbing systems of unused or slightly used buildings (as defined by industry organizations including NSF International, Centers for Disease Control and Prevention (CDC), and the International Association of Plumbing & Mechanical Officials (IAPMO).
In commercial and institutional buildings, the IntelliStation digital water mixing system distributes mixed hot water across a hot water recirculation loop. Facilities managers can monitor and adjust water temps remotely using this digital technology, which can be connected to a building automation system (BAS).
Begin by compiling a list of safeguards for employees and visitors. Consider hiring a water quality specialist or expert. Also, ask the following questions to the local water utility:
- Have you had any recent water supply problems?
- Have all of the regular checkpoints been checked?
- What is the disinfectant concentration right now?
Make A Map Of The Building’s Plumbing System
Draw a diagram of the building’s water system to locate low-use water outlets before the first flush. Plan a unidirectional cleansing sequence that begins at the water supply’s point of entry and continues to the periphery distal points and point-of-use outputs such as faucets and showerheads.
The water supply in big buildings is often divided into zones and branches, such as various wings. Each wing or pair of branches is typically supplied by the same riser. Always begin planning out the plumbing system with the outlet closest to the water supply and work your way out to the furthest outlets. The complete recirculating loop, including cold and hot water, all accompanying equipment and appliances, and all outlets, including faucets, showerheads, eyewash stations, ice machines, hot tubs, therapeutic pools, and water features, should all be flushed along this path.
Create A Flushing And Cleaning Routine
Create or re-create a flushing and cleaning routine. Flushing is vital because it removes low-quality water that has been collected due to infrequent usage and replaces it with high-quality municipal water. Freshwater helps to prevent the loss of protective scale and biofilm formation that may occur when water is stagnant.
Following the first flush, regular flushes should be planned to assist restore destabilized scale and preventing biofilm formation. Watts’ OneFlow System, seen above, employs a specially developed medium to turn scale-forming molecules into harmless crystals that won’t attach to pipes or components, thereby eradicating scale.
These circumstances must be addressed because they encourage the spread of Legionella and other waterborne infections, putting persons with weakened immune systems in danger. An initial flush, scheduled flushing, cleaning of fixtures and equipment, testing and monitoring, and repeated flushing as required are all part of the proper flushing process.
Before resuming regular building operations, the first flushing and cleaning must be done. The sooner you start flushing, the better. Even if the building’s reopening date is still undetermined, have personnel begin flushing as soon as feasible. The sooner a flushing routine is started, the faster the water quality will improve. Prior to flushing, workers should get sufficient training and be equipped with PPE (personal protective equipment). On OSHA’s website, there is information on how to do this.
Flushing the whole pipe system from point of entry to point of usage is critical. This covers all water outlets, utility sinks, hose taps, and piping that is already in use, as well as pipe and fixtures that will be installed in the future. However, it’s not a bad idea to pay extra attention to the portions of the water system that are most likely to make people ill. These are some of them:
- Faucets for drinking water or preparing meals
- Fountains of water
- Refrigerators with ice makers and ice machines
- Sprayers for kitchen sinks
- Aerosol-producing water features (fountains, spas, etc.)
- Children, the elderly, and other vulnerable persons utilize parts of the water system.
An initial flush removes impurities that have collected during stagnation and introduces new, high-quality water into the pipe system. Cleaning the fixtures eliminates pollutants from the point of discharge’s complicated internal systems. Flushing includes an initial flush to remove low-quality water and pollutants, as well as subsequent flushes that may restore the building’s water quality to pre-COVID-19 levels. Continuous flushing removes particulates from the system and introduces disinfectant from the municipal system, which may assist prevent biological development. The longer the service is down, the more work it will take to get it back up and running.
Once the building has been reopened, check that the tempering valves are still maintaining the proper temperature.
Starting with the zone nearest to the water building supply, flush each zone one by one. Start with the cold water plumbing in each zone, then go on to the hot water. Open taps inside the zone, beginning with the outlet nearest to the zone origin and working your way out. The flushing process should not be completed until the furthest point-of-use tap has flushed for at least five minutes and the cold water temperature at the farthest tap has remained steady.
Consider the following factors to ensure that flushing is as effective as possible:
- During the whole flushing operation, all valves should be completely opened.
- Aerators should be eliminated entirely. If the aerators will be used again, clean or replace the screens before reinstalling them.
- Disinfecting and sterilizing showerheads and faucets is a good idea. If vulnerable people have access to outlets, consider replacing them.
- Adjust valves back to regular operating settings before running the system after flushing.
All sites where water is kept should be identified, emptied, and flushed with clean cold water as part of the flush. Humidifiers, ice makers, and dishwashers are just a few examples. Water treatment devices such as filters and water softeners are found in almost every building’s plumbing system. These should be run normally, included in the flush, and not skipped.
All hot water tanks should be evacuated after the flow has resumed after this first flush. The heater should not be switched off and the temperature should be maintained. It is critical to maintaining continuous functioning in order to avoid microbial growth. Ensure that the temperature of the water heater storage is high enough to destroy germs (131 to 140°F).
Following the first flush, regular flushes should be planned to assist in restoring a destabilized scale and preventing biofilm formation. Continue flushing for a minimum of 12 weeks, according to the American Water Works Association (AWWA). This permits the protective scale to re-establish itself and hazardous lead particles to be flushed out of the plumbing system.
For continued flushes, the following suggestions are made:
- At least once a day, open each point-of-use tap.
- During regular flushing, flush the whole building once a week.
- During continuous flushing, it is not essential to empty the water storage.
- Separately flush the cold and hot water systems; cold first, hot second.
Testing And Monitoring
Testing and monitoring should start for Legionella, other bacteria growth, and disinfectant levels prior to the initial flush, throughout the ongoing flushing, and on a predetermined schedule going forward. Testing and monitoring are the only ways to know the health of the plumbing system.
Disinfectant levels should be monitored at the conclusion of the first flush. After the tap has been flushed, the concentration level of chlorine, the most often used disinfectant, should be tested at the point of entry and in the cold water of the furthest tap in each zone. The protection offered to the whole plumbing system may be determined by comparing the point-of-entry concentration to the distal tap concentration.
If alternative disinfectants, such as monochloramine, are employed, be careful to monitor and compare their concentrations at the site of entry and at the distal outputs. The temperature of the water should be checked and documented on a regular basis.
A professional laboratory should test the system for Legionella. Many institutions will hire a consultant to help them with this procedure. Samples should be taken at least 48 hours after the water system has been flushed and returned to regular functioning. To guarantee accuracy and avoid false-negative findings, many samples should be obtained. From the point of entry to the point of usage, samples should be obtained at several points throughout the system.
If Legionella levels are found to be too high, hyper chlorination or shock disinfection should be used. This occurs when a higher-than-normal quantity of chlorine is pumped through the plumbing system for a certain period of time, and the water temperature is adjusted to speed up the death process. All fixtures in the cold water system should be flushed from point of entry to point of usage. The CT of the water should be at least 3,000 mg/min/L. The disinfectant concentration and contact time with the water being disinfected are referred to as the “CT” value.
Systems with a lot of Legionella or that are known to have a lot of biofilm and may need even higher CT objectives. Shorter disinfection contact periods may be possible with a higher chlorine dose. Always take care to ensure that occupants are not exposed inadvertently. There should be strict access constraints in place. At the end of the treatment, do tests to check that the chlorine levels are within normal limits. After the hyper chlorination is finished, the system should be given another heat flush.
Hyperchlorination should be considered even if unacceptable Legionella levels are not identified following thermal flushing, particularly in buildings where high-risk or immune-compromised populations may be exposed.
Keeping Track Of, Changing, And Developing A Water Management Strategy
A facility management team should record all testing and monitoring practices including the frequency, locations, and results. If there is a water management plan, those findings should be integrated into the record-keeping portion of the plan. If a water management plan does not exist, we strongly encouraged the creation of one. Most healthcare facilities are required under the Centers for Medicare & Medicaid (CMS) mandate to have a water management plan. Failing to do so can cause a facility to lose Medicaid and Medicare reimbursements.
A water management strategy, as specified in ASHRAE 188, will assist in maintaining a high degree of quality in a facility. The Centers for Disease Control and Prevention (CDC) has created a toolkit based on ASHRAE 188 for water management plans. The toolkit assists in determining the risk levels of various building types and technologies, as well as walking users through the needs of a healthy water management strategy step by step.
Recommissioning And Maintenance
All mechanical equipment should be examined as part of the process of reopening a building. Towers for cooling, boilers, pumps, backflow preventers and digital mixing stations are all examples. The water systems and equipment should be recommissioned as if they were a brand new structure. Ensure that any planned maintenance that was missed during facility closures is done and reported according to standard procedures.
The following are some basic guidelines:
Thermostatic Digital Mixing
- If the building will be closed for an extended period of time, drain the plumbing system before shutting.
- If emptying the system isn’t an option, raise the temperature of the hot water being produced and stored over 150° F, and keep the building pump operating at full speed by bypassing a TMV or setting the DMV to full hot.
- Purge any dead legs on a regular basis to maintain the system relatively clean.
- Perform a high-temperature water purge, a hyper chlorination shock, or both at the same time.
- In most cases, mixing valve calibration is unnecessary.
- Once the facility has been reopened, verify that the tempering valves are maintaining the proper temperature.
- Examine the area visually.
- All reduced pressure zone units must be repressurized appropriately, and the relief valve must be closed if the water supply was totally switched off and the pressure dropped.
- All pressure breaker valves must be properly repressurized, and the relief valve must be shut.
- Even though the pressure breaker valve should be spill-proof, it should still be examined.
Connectors For Gas
- Assuming that all equipment has been switched off, a device like the FloProTM-MD may help with a startup check to confirm that everything is working as it should.
- Ensure that any gas-burning device with a BTU rating of 325,000 BTUs or less, whether in a commercial kitchen or not, has a suitable gas supply.
System Of Drainage
- There are no specific criteria for common drains. A visual check, on the other hand, should be part of the reopening strategy.
Stainless steel piping and System of drainage
- Except for the lack of water in the traps due to reverse siphonage or evaporation, stainless steel pipe systems do not need any particular considerations when returning to full operation after periods of inactivity.
- Stainless steel pipe and fittings are resistant to corrosion induced by organic matter breakdown and subsequent generation of hydrogen sulfide gas, as well as microbiologically influenced corrosion.
- Purge the system with hose bibs or flush it out with flush valves open to provide a continuous flow of water.
- Check the tanks to see whether the aerator is working and the inflow pre-filter is in good working order.
Solutions for improving water quality It is recommended that most water quality equipment be flushed. However, it’s always a good idea to check the manufacturer’s instructions for each gadget.
- Check to see whether the light is operating properly.
- Verify that any planned maintenance hasn’t been overlooked.
- Examine the vessel visually.
Filtration At The Point Of Entrance (Sediment)
- Examine the situation visually.
- If there are any obstructions, clean them out and replace the filters as required.
Filters For Usage At The Point Of Use
- Examine the situation visually.
- If there are any obstructions, clean them out and replace the filters as required.
- Verify that any planned maintenance hasn’t been overlooked.
Instrumentation For Measuring
- If there is a rapid loss of power or power is off for a lengthy period of time in measuring instruments such as the CIX Instrument from HF scientific (chlorine measurement), reagents may precipitate in the tubes.
- If crystallization occurs during the inspection, the unit must be primed and the reagents must be changed.
- Cleaning the snow/ice detector with soap and water is recommended.
- Examine the controlled display for any problem warnings caused by defective sensors.
Heaters For Water
- Check with the manufacturer to see whether emptying the water heater after an extended period of inactivity is recommended.
- Ensure that all maintenance tasks are completed by experts or in accordance with the manufacturer’s guidelines.
- Make sure the water heater is set to at least 122°F, and for a faster kill, try higher temps (131°F-140°F).
- Ensure that measures are taken to prevent scalding if the water heater is set to >130°F
- Wipe off the exterior and use a disinfectant to keep it clean.
- An authorized service person should perform a proper setup.
- Perform a thorough blowdown of all components.
- Check combustion and calibration, test all safety devices, and double-check that all system operating parameters are right and working.
Inspection Of Additional Equipment
Spas, Treatment Pools, And Hot Tubs
- Before using, check for any existing rules from local or state regulatory agencies.
- Examine the situation visually. for slime and biofilm prior to refilling.
- Before using a hot tub or spa, follow the CDC’s instructions for disinfection.
Towers For Cooling
- Examine the starting and shutdown routines once again.
- Follow the manufacturer’s instructions as well as industry best practices.
- Examine the situation visually. for slime and biofilm prior to use
- Proceed with disinfection treatments assuming the cooling tower has been adequately maintained. The Cooling Technology Institute offers advice at http://www.cti.org/downloads/WTP-148.pdf.
After The System Has Been Reopened, It Must Be Maintained
The reopening procedure should include planned and detailed cleaning. This involves filter replacement from the point of input to the point of usage, as well as correct maintenance of all equipment and fixtures. Follow the manufacturer’s instructions and, if required, notify the appropriate authorities.
A set of inspections is advised twenty-four hours before reopening the building. Raise the temperature of the hot water system to 140 degrees Fahrenheit. Open all outlets and flush until they reach a temperature of at least 131 degrees Fahrenheit. Conduct a last round of sampling after flushing to confirm there is no pollution.
Once the building has resumed normal operation and the water system is back to standard function, the main priority will be maintaining water system quality and safety. If there is no water management plan prior to the disruption, create one immediately. This should include a schedule for Testing and monitoring disinfectants, bacteria levels, and water temperature. Follow the plan, document activities, and adjust as needed. If an issue arises, promptly address it and notify authorities if deemed necessary.
If the building is expected to reopen in less than a month, keep the standard control regime in place. There are actions that may be performed during this period to boost water quality prior to pre-open flushing and chlorination if the time to reopen the building is undetermined, or if it is slated to reopen more than one month away.
Take into account the following:
- Maintain your system on a weekly basis while it isn’t in use.
- Conduct visual checks once a week.
- To avoid seizure and failure, start operating moving components like pumps for at least 10 minutes every week.
- To minimize bacteria development, raise the water temperature to 140° F for at least 1 hour every week.
- If your water heater has a thermal sterilization cycle, use it according to the manufacturer’s instructions.
- Keep disinfectant levels at normal.
- Weekly outlets should be flushed.
- Ensure that all storage areas have adequate disinfectant levels.
- All monitoring, testing, and activities should be documented.
- Drain and dry if feasible if certain systems have to be shut off.
If the decision has been made to not heat water within the plumbing system during the closure, then Take into account the following:
- Do not drain the system or close the building.
- Turn off the water supply, the storage tanks, and the drain.
- Prior to the shutdown, consider doing thermal flushing and hyper chlorination.
If a facility is not completely shut down but will be used seldom, consider the following choices for system maintenance:
- To maintain temperature and disinfection, flush cold water systems on a frequent basis. The residual free chlorine should be at or above. 2 micrograms per liter
- At distant outlets, keep an eye on the hot water system and make sure it’s in good working order.
- Monitor and record the temperature of the supply water as well as the disinfectant concentration.
- Restrict access to any parts of the building that aren’t in use.
- All monitoring, testing, and maintenance should be documented.
When planning to reopen an underused or infrequently used facility, there are a variety of tools and guidelines available to help maximize water safety and minimize water risks:
- Model Aquatic Health Code from the Centers for Disease Control and Prevention.
- Following a Boil Water Advisory or Water Supply Disruption, CDC Healthcare Water System Repair and Recovery.
- Standard 188 of the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE): Legionellosis Risk Management for Building Water Systems.
- Minimizing the Risk of Legionellosis in Building Water Systems, ASHRAE Guideline 12.
- Legionellosis Guideline 2008, Cooling Technology Institute (WTP-148).
- Legionellosis Guideline 2019 (GLD 159) from the Cooling Technology Institute.
You can learn more about how to keep business buildings safe by reducing the danger of Legionella and other waterborne germs by doing further research.
The “is stagnant water a biological hazard” is a question that begs an answer. Stagnant water can cause many problems, and it is important to know how to handle the situation.
Once the building is re-opened, its systems must continue to be maintained. For more, see Maintaining Drain, Waste, And Vent Systems In Buildings.
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