Key Considerations for Reopening Facilities with Stagnant Water Systems

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通过贾纳Summey

A few months after the “reopening” of the economy, understandably, business owners and government officials welcomed a return to normalcy. However, new and different risks are faced when reopening dormant buildings with stagnant water systems.

Several weeks of zero flow, low flow, and tempered water can result in microbiological growth, leeching heavy metals, and corrosion within our plumbing systems.

规划是关键

让我们来仔细看步建立设备管理人员,以保持在管道系统水质安全应该考虑未使用或使用略微建筑(as defined by industry organizations including NSF International, Centers for Disease Control and Prevention (CDC), and the International Association of Plumbing & Mechanical Officials (IAPMO).

Key Considerations for Reopening Facilities with Stagnant Water Systems, COVID-19, post COVID, Watts Water Technology, Watts Intellistation, Watts OneFlow

The IntelliStation digital water mixing system delivers mixed hot water throughout a hot water recirculation loop in commercial and institutional facilities. This digital solution can be integrated into a building automation system (BAS) to allow facilities managers to remotely monitor and control water temperatures.

Begin by documenting protection measures for staff and visitors. Consider working with a water quality expert or consultant. And, ask the local water utility the following questions:

  • 是否有过任何近期供水中断?
  • 有标准的检查站被检查?
  • 什么是当前的消毒剂的浓度?

If one isn’t already in place, create a map of the building’s plumbing system.

在初始冲洗之前,勾勒出建筑给排水系统,以确定低使用出水口。绘制出一个单向的过程中冲洗方案开始在供水的点进入,到周边distalpoints,并点使用的店铺,如水龙头和淋浴花洒。

在大型建筑,供水常常被设计在地区和分支,如不同的翅膀。典型地,分支的每个翼或组将用相同的立管来服务。当映射出管道系统,总是从最近的供水出口开始并继续到最远端的出口。沿着这条路线,冲洗方案应包括整个循环回路,冷,热水,所有相关设备和用具及所有网点包括水龙头,淋浴花洒,洗眼器,制冰机,热水浴缸​​,治疗池,水景。

Establish or reestablish a flushing and cleaning regimen. Flushing is important because it clears out the low-quality water that accumulated during low use and replaces it with high-quality water from the municipal supply. The fresh water helps mitigate loss of protective scale as well as biofilm growth that emerged while the water was stagnant.

Key Considerations for Reopening Facilities with Stagnant Water Systems, COVID-19, post COVID, Watts Water Technology, Watts Intellistation, Watts OneFlow

After the initial flush, ongoing flushes should be scheduled; continual flushes help to repair destabilized scale and minimize biofilm growth. Watts’ OneFlow System, shown here, uses a specially designed media where scale forming molecules are transformed into harmless crystals that won’t stick to pipes and components, eliminating scale for good.

这些条件需要,因为它们繁殖军团菌和其他水生病原体的生长加以解决,从而为那些免疫系统受损的高风险环境。适当的冲洗是包括初始冲洗,冲洗测序,清洁装置和设备,检测和监测,并根据需要附加的冲洗一个多步骤的过程。

初步冲洗和清洁必须恢复正常建设运营之前完成。越早冲洗开始,就更好了。如果有可能,工作人员现在开始冲洗,即使建筑物的重新开放日期仍是未知数。冲水方案开始得越早,越早水质将恢复正常。法拉盛之前,适当的工作人员的培训应完成并应提供PPE(个人防护装备)。指导本可以在OSHA的网站上找到。

这是至关重要的,从点的进入点使用冲洗整个管道系统。这包括所有的出水口,实用水槽,软管接头,管道目前使用的,以及管道和装置的地方,以便将来安装。但是,它不会伤害采取特殊的通知水系统具有使人生病的最大机会的部分。这些包括:

  • 用于饮用的水或食物准备龙头
  • 饮水机
  • 制冰机和冰箱用制冰机
  • 阵雨
  • Kitchen sink sprayers
  • 产生气溶胶(喷泉,温泉等)水景
  • 儿童,老人以及其他易感人群使用的供水系统的部件

初始冲洗清除了污染物的停滞期间积累并在新鲜的,高品质的水汲取到管道。清洁夹具在放电点去除复杂的内部结构的污染物。法拉盛需要一个初始冲洗摆脱低质水和污染物,以及后续可能带来大楼回到前COVID-19水质冲洗。持续冲洗,并通过从系统中抽取颗粒和从市政系统,可以帮助控制生物生长消毒剂带来的。更长的服务中断,更多的精力将需要修复。

Key Considerations for Reopening Facilities with Stagnant Water Systems, COVID-19, post COVID, Watts Water Technology, Watts Intellistation, Watts OneFlow

一旦建筑物被重新打开时,进行确保回火阀正常过程中维持所希望的温度。

按区域冲洗区,从最接近水建材供应的区域。在每个区域,开始用冷水管道第一,其次是热水。在该区域,打开水龙头开始最接近区原产地出口,向着最远点的工作。冲洗不应结束,直到点的使用最远抽头已冲洗至少五分钟,冷水温度在最远端的抽头是恒定的。

为了冲洗是最有效的,考虑以下因素:

  • 在整个冲洗过程所有阀门应处于全开位置
  • 所有的每个都应该被删除。如果继续使用我s planned, clean or replace the screens prior to reinstalling the aerators
  • Showerheads and faucets should be disinfected and sterilized. Consider replacing outlets if vulnerable populations have access
  • 此前冲洗后运行系统,调节阀返回到正常工作位置

As part of the flush, all locations where water is stored should be identified, drained, and flushed with clean cold water. Examples include humidifiers, ice machines, and dishwashers. Most buildings have some form of water treatment in their plumbing system such as filters and water softeners. These should run as normal, be included in the flush, and should not be bypassed.

Once flow has returned after this initial flush, all hot water tanks should be drained. Temperature should be maintained, and the heater should not be turned off. Continual operation is important to prevent microorganisms from growing. Make sure that water heat storage temperature are sufficient to kill bacteria (131 to 140°F).

After the initial flush, ongoing flushes should be scheduled; continual flushes help to repair destabilized scale and minimize biofilm growth. The American Water Works Association (AWWA) recommends continued flushing for a minimum of 12 weeks. This allows the protective scale to re-stabilize and for harmful lead particles to be washed through the plumbing system.

Recommendations for ongoing flushes include:

  • Open each point-of-use tap at least once per day
  • Flush the entire building once per week during ongoing flushing
  • It is not necessary to drain water storage during ongoing flushing
  • 继续单独冲洗冷热水系统;冷第一,第二热

Monitoring and testing

Monitoring and testing 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. Monitoring and testing are the only ways to know the health of the plumbing system.

At the end of the initial flush, disinfectant levels should be checked. The concentration level of chlorine, the most commonly used disinfectant, should be measured at the point-of-entry and in the cold water of the most distant tap of each zone after the tap is flushed. Comparison of the point-of-entry concentration to the distal tap concentration will give an indication of the protection being provided to the entire plumbing system.

如果使用其他消毒剂,如氯胺,一定要测量并点入和远端网点比较其浓度。水温应定期进行测试和记录。

该系统应为军团菌通过认证的实验室进行测试。许多设备会选择工作,这个过程的顾问。样品应收集最后的冲洗和水系统的正常运行返回后至少48小时。多个样品应收集,以确保准确性和防止假阴性结果。样品应在整个系统中的多个位置进行拍摄,从点的进入点使用。

如果测试证明军团菌的不可接受的水平Hyperchlorination或休克消毒应进行。这是高于正常水平的氯通过管道系统冲洗特定的时间长度,并且水温度上升快速杀灭。冷水系统应该从点进入被刷新到点对点的使用,包括所有的灯具。水应该达到不低于3000 mg。分钟/ L的CT。“CT”值的消毒剂和接触时间的浓度与水被消毒。

Systems that have high levels of Legionella, or are known to have heavy biofilm, may require even higher CT targets. Higher chlorine dosage may allow for shorter disinfection contact times. Always take proper precautions to ensure there is no inadvertent exposure to occupants. Strict access controls should be in place. Conduct testing to ensure chlorine levels are in normal ranges at the conclusion of treatment. When hyperchlorination is complete, the system should go through an additional thermal flushing.

即使热冲洗后都没有发现不可接受水平的军团菌,hyperchlorination仍然应该考虑,特别是在建筑物中高风险或免疫受损的人群可能会暴露。

Following, adjusting, and creating a water management plan

A facility management team should record all monitoring and testing 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.

Implementing a water management plan as outlined in ASHRAE 188 will help maintain a high-quality level in a building. The Centers for Disease Control (CDC) has developed a water management plan toolkit based on ASHRAE 188. The toolkit aids in the understanding of risk levels of different building types and devices and walks step by step through the requirements of a healthy water management plan.

维护和重新调试

As part of the process of reopening a building, all mechanical equipment should be inspected. Examples include cooling towers, boilers, pumps, backflow preventers and digital mixing stations. Essentially, the water systems and equipment should be recommissioned as if it were a new building. Make sure any scheduled maintenance that may have been missed during building closings are completed and recorded in accordance with normal practices.

一些一般性的指导原则包括:

Digital thermostatic mixing

During/before closing

  • Drain the piping system prior to closing if planning for a long-term building closure
  • 如果排水系统不是一个选项,增加生产和热水贮存高于150°F,并通过绕过一个TMV或设置DMV完整热保持建筑物的泵在整个温度运行
  • Conduct a periodic purge of all dead legs to keep the system reasonably clean

At reopening

  • 行为或者是高温水清洗,hyperchlorination休克,或两者
  • Generally, calibration of mixing valves is not needed
  • 一旦建筑物被重新打开时,进行确保回火阀正常过程中维持所希望的温度

回流

  • Conduct a visual inspection
  • If the water supply was completely shut off and the pressure decreased, all reduced pressure zone units need to be repressurized correctly, and the relief valve should be closed
  • 所有的压力断路器的阀门也需要正确地再加压和泄压阀应关闭。
  • 压力破坏阀应防泼水,但它仍然应该检查

燃气连接器

  • Assuming equipment has been turned off, a device such as FloPro™-MD can assist with a startup check to ensure each piece is operating at manufacturer’s specification
  • 验证适当的气体供应的气体燃烧器具与325,000 BTU的或更少的BTU的评价,无论是在商业厨房或不

Drainage systems

  • For general drains, there are no special requirements. However, a visual inspection should be part of the reopening plan

不锈钢管道和排水系统

  • Other than the absence of water in the traps from either back siphonage or evaporation, stainless steel piping systems require no special considerations when being returned to full service after periods of non-use
  • Stainless steel pipe and fittings are resistant to corrosion caused by decomposition of organic matter and the subsequent formation of hydrogen sulfide gas or microbiologically-influenced corrosion

Rainwater harvesting

  • Purge the system via the hose bibs or flush out the system by opening the flush valves to create a steady flow of water
  • Check the tanks to ensure the aerator is functioning and the inlet pre-filter is in service

水质解决方案
对于大多数水质的设备,这是一个好主意,冲洗单元。然而,它总是最好请教制造商的指导方针为每个设备。

UV systems

  • Inspect to ensure the light is working correctly
  • Check to make sure any scheduled maintenance wasn’t missed
  • 目视检查船只

Sediment/point-of-entry filtration

  • Visually inspect
  • 清洁任何堵塞并在需要时更换过滤器

Point-of-use filters

  • Visually inspect
  • 清洁任何堵塞并在需要时更换过滤器
  • Check to make sure any scheduled maintenance wasn’t missed

测量仪器

  • In measuring instruments such as the CIX Instrument from HF scientific (chlorine measurement), there is a potential for reagents to crystallize in the tubes if there is a sudden loss of power or power is off for an extended time
  • During inspection, in the rare event that crystallization has occurred, the unit needs to be primed and reagents replaced

Snow melt

  • 雪/冰探测器应该用肥皂和水清洗
  • Inspect the control display to ensure there are no error messages due to faulty sensors

热水器

  • 如果确定制造商建议的非使用延长的时间段之后将水排出加热器
  • 确保所有维护活动都是由专业人士进行,或根据制造商的说明
  • Make sure the water heater is set to at least 122°F and consider higher temperatures (131°F -140°F) for a quicker kill
  • Ensure that measures are taken to prevent scalding if the water heater is set to >130°F
  • 擦拭外和控制用消毒液
  • 由授权服务代理进行适当的启动
  • Conduct a significant blowdown of all components
  • 检查燃烧和校准,执行所有安全装置试验,并确认所有的系统运行参数是否正确和运作

附加设备进行检查:

Hot tubs, spas, therapy pools

  • 开放使用前检查从当地或国家监管机构(IES)现有准则
  • Visually inspect for slime and biofilm prior to refilling
  • Perform a hot tub/spa disinfection procedure before use per CDC guidance

Cooling towers

  • Revisit startup and shutdown procedures
  • Follow manufacturer guidelines and industry best practices
  • 视觉在使用前检查是否有粘液和生物膜
  • Assuming the cooling tower has been well maintained, proceed with disinfection procedures. Guidance can be found from the Cooling Technology Institute:https://www.cti.org/downloads/WTP-148.pdf

重启后,系统维护

Planned and detail cleaning should be part of the reopening process. This includes proper maintenance of all equipment and fixtures, and the replacement of filters from point-of-entry to point-of-use. Be sure to follow manufacturer guidelines and contact the proper authorities when necessary.

前24小时开放,我t’s recommended to conduct a round of checks. Bring the hot water system back up to 140° F. Open all outlets and flush until they reach a minimum of 131° F. After flushing, conduct a final round of sampling to ensure there is no contamination.

一旦已经恢复正常运行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 monitoring and testing 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.

如果建筑物被安排在一个月内重新打开,继续正常的控制方案,如果可能的话。如果重新建设的时间是未知的,或者如果它计划再开1个月走更长,有可能在此期间提高水质之前预开冲洗和氯化采取预防措施。

考虑以下:

  • 开展低使用率每周例行维护
  • Conduct weekly visual inspections
  • Initiate operation of moving parts such as pumps for at least 10 minutes per week to prevent seizure and failure
  • Increase water temperature to 140° F for at least 1 hour per week to reduce bacteria growth
  • If equipment such as a water heater has a thermal sterilization cycle, utilize it per manufacturer recommendations
  • 维持正常水平消毒剂
  • 每周冲洗店
  • Ensure all storage maintains proper disinfectant levels
  • Document all activity, monitoring, and testing
  • 如果决定关闭某些系统,排水和干燥如果可能的话

If the decision has been made to not heat water within the plumbing system during closure, then consider the following:

  • Close the building and do not drain the system
  • Turn off storage tanks, drain, and the water supply
  • 考虑停机前进行热冲洗和hyperchlorination

如果建筑物没有被完全关闭,但将低使用条件下,可以考虑下列选项来维护系统:

  • Flush cold water systems on a regular schedule to maintain temperature and disinfectant. Free chlorine residual should be at or above .2 mg/L
  • 监控并保持在远端网点热水系统
  • 监控和记录供水温度和浓度的消毒剂
  • Restrict access to any unused portions of the building
  • Document all monitoring, testing, and maintenance

Additional Resources

There are a multitude of tools and guidance to assist in maximizing water safety and minimizing water risks when preparing to reopen an unused or slightly used building:

  • CDC型号水产健康守则
  • CDC保健水系统修复和恢复继沸水咨询或中断供水
  • ASHRAE Standard 188: Legionellosis Risk Management for Building Water Systems
  • ASHRAE指南12:最大限度地减少军团病相关的与建筑给水排水系统风险
  • Cooling Technology Institute Legionellosis Guideline 2008 (WTP-148)
  • 制冷技术研究所军团准则2019(GLD 159)

Learn more about ensuring safety in commercial buildings by mitigating the risk of Legionella and other waterborne bacteria atwww.legionella-strategies.com

Jana Summey, MBA, Watts Healthcare Vertical Market Manager, has nearly 20 years’ experience in the MEP (mechanical/electrical/plumbing) design and architectural design industries. She is a popular speaker on mitigating Legionella through a multi-barrier approach in on-premise plumbing systems – from point of source to tap. Recently Jana navigated her mother through the experience of being exposed to Legionnaires’ as a hospital patient, gaining valuable insight into the serious threat Legionella poses for at-risk populations.