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Year : 2014  |  Volume : 57  |  Issue : 3  |  Page : 435-438
Role of water quality assessments in hospital infection control: Experience from a new oncology center in eastern India

1 Department of Microbiology, Tata Medical Center, Kolkata, West Bengal, India
2 Department of Medical Administration, Tata Medical Center, Kolkata, West Bengal, India
3 Department of Maintenance Engineering, Tata Medical Center, Kolkata, West Bengal, India

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Date of Web Publication14-Aug-2014


Water quality assessment and timely intervention are essential for health. Microbiology, total dissolved solids (TDS) and free residual chlorine were measured for water quality maintenance in an oncology center in India. Impact of these interventions over a period of 22 months has been demonstrated with four cardinal events. Pseudomonas in hospital water was controlled by adequate chlorination, whereas high TDS in the central sterile supply department water was corrected by the installation of electro-deionization plant. Contaminated bottled water was replaced using quality controlled hospital supply. Timely detection and correction of water-related issues, including reverse osmosis plant was possible through multi-faceted approach to water quality.

Keywords: Chlorine, Pseudomonas, reverse osmosis, total dissolved solids, water quality

How to cite this article:
Bhalchandra R, Chandy M, Ramanan VR, Mahajan A, Soundaranayagam JR, Garai S, Bhattacharya S. Role of water quality assessments in hospital infection control: Experience from a new oncology center in eastern India. Indian J Pathol Microbiol 2014;57:435-8

How to cite this URL:
Bhalchandra R, Chandy M, Ramanan VR, Mahajan A, Soundaranayagam JR, Garai S, Bhattacharya S. Role of water quality assessments in hospital infection control: Experience from a new oncology center in eastern India. Indian J Pathol Microbiol [serial online] 2014 [cited 2023 Jun 3];57:435-8. Available from:

   Introduction Top

Good quality water is an essential prerequisite to ensure optimal patient care, and the well-being of the staff and visitors in a hospital environment. [1],[2] At the Tata Medical Center, we follow three parameters water quality assessment done randomly in various areas, but on a regular basis. The objective of this article is to demonstrate the impact of water quality assessment in hospital infection prevention and control.

   Methodology Top

This prospective observational study of water quality parameters with engineering interventions was done at Tata Medical Center, which is a newly built oncology and bone marrow transplantation (BMT) center in Kolkata (Eastern India). The hospital has 167 in-patient beds. In the last year 4971 and 10971 patients received in-patient and out-patient care, respectively.

The water quality was assessed using:

  • Total dissolved solids (TDS) meter: For the measurement of TDS (DiST 3 TDS meter, Hanna Instruments, Romania) [1]
  • Chlorine meter: For the measurement of free or residual chlorine (CL-2006, Lutron, Taiwan) [1],[3]
  • Membrane filtration technology for water microbiology (Millipore Microfiltration System 1-PL, India). [1],[2]

These findings have been consistently checked over a period from October 2011 to May 2013.

   Results Top

The impact of water quality assessment using the above three methodologies are being discussed using four cardinal events [Table 1]:
Table 1: List of events with regard to water quality assessment and actions taken

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Event 1: Pseudomonas in hospital water

Testing with these methods revealed the presence of Pseudomonas aeruginosa in numbers above the acceptable limits for hospital water (0/250 mL of water). [2] Manual as well as electronic chlorine measurements revealed low levels of free (residual) chlorine in hospital water supplies. Root-cause analysis showed that although chlorination of water (post-reverse osmosis [RO] filtration) was being done, by the time the water reached end-users, the chlorine level was falling below the WHO recommendations (0.2-0.5 ppm of residual chlorine). [3] As a follow-up action, additional chlorine using sodium hypochlorite (NaOCl) solution was added to overhead tanks regularly, and levels of residual chlorine maintained within acceptable limits (0.2-0.5 ppm). This intervention eliminated the presence of P. aeruginosa, from the hospital water supply and drastically reduced the aerobic colony count from the water provided to the end-users. The event also demonstrates the importance of chlorine meters in ensuring adequate chlorine in the water supply, and to spot breaks in the routine process. The event also substantiates the strengths of membrane filtration technology, which is very effective in detection of nonfermenters, since early detection could prevent colonization of the supply lines.

Event 2: Central sterile supply department water quality

Water quality was regularly monitored in the central sterile supply department (CSSD) and was between 60 and 70 ppm, which is unsuitable for the purpose of final rinsing of high-end surgical instruments, including endoscopes. High TDS water may lead to scale build up over pipelines and instruments, and is not ideal for the operation of washer-disinfectors and autoclaves. The recommendation from Aesculap (surgical instrument manufacturer) suggests that the TDS of supply water should be <10 ppm. Washer-disinfectors generally operate with water hardness values up to 125 mg/L CaCO 3 but are more effective and cheaper to operate when the hardness of the water is within 50 mg/L CaCO 3 . To avoid the risk of corrosion, it has been recommended by the UK Department of Health that water used in the cleaning of stainless steel instruments should have a chloride concentration <120 mg/L and for final rinse/disinfection, <10 mg/L Cl. Chloride concentrations >240 mg/L Cl - cause pitting to occur. The conductivity at 25°C should not exceed 30 μS/cm (TDS = 19.2 ppm) for RO water. [4] Based on regular TDS measurements and the above recommendation, the water purification system was changed to an electro-deionization system. Currently, the TDS has been reduced to 2-5 ppm.

Event 3: Replacement of bottled drinking water by hospital mains water for water dispensers

Routine analysis of some packaged drinking water bottles/jars, using membrane filtration technology revealed a persistently high aerobic colony count, and the occasional presence of coliforms and P. aeruginosa in the bottled drinking water (BDW) supply. The microbes were identified using standard microbiological methods. Consequent to the observation, expensive externally sourced BDW supply, that was incurring an expense to our institution, of about Rs. 50,000/- or approx $1000/month), was replaced by RO water from the main hospital water supply having TDS, chlorine levels and microbiology of satisfactory quality. The results were also communicated to the bottled water manufacturer for necessary action.

Event 4: Identifying a problem with the reverse osmosis plant

It was revealed in late March 2013 that the TDS in the RO plant (General Electric, USA) was high and the taste of drinking water was altered. This led the infection control team to check the quality of the drinking water since the TDS of the water coming from the main water supply had risen remarkably (median TDS: Readings ranged from 650 to 750 ppm). Further checks led to the finding that the residual chlorine was low, with a high aerobic colony count. Additional investigation in and around the RO plant revealed major problems with the RO system, triggered by a damaged strainer of the sand filter, which in turn had damaged the RO membranes. Identification of the problem led to a prompt replacement of the damaged membranes and subsequent restoration of normal water supply.

   Discussion Top

The importance of water quality in daily hospital operations is clear, but the means of maintaining that quality is not always well-defined. We can summarize the importance of this work in water quality assessment in hospital as follows:

  1. Self-reliance in assessing water quality,
  2. Relatively low cost, but high-impact intervention,
  3. Significance in the context of developing and tropical countries where water borne diseases are endemic,
  4. Significance for hospital, including those caring for immunocompromized patients emphasizing the need to focus on a fundamental aspect of health that is water.

The technology used in this hospital for water quality assessment is not unique, but in this instance, it has been used not just for a passive observation but for specific interventions, which improve the quality of water and by implication the safety of patient care services. The total investment required for the equipments were about Rs. 100,000 (about $2,000; Rs. 5000 for the TDS meter; Rs. 20,000 for the manual and electronic chlorine meter; and Rs. 75,000 for the membrane filtration system for water microbiology; cost of three parameter analysis per sample of water is about Rs. 50 or $1). Water in the hospital is used for general applications (drinking, bathing of patients, washing of linen, utensils, hand hygiene, cooking, toilets, etc.) as well as for specialized operations (such as medical equipment cleaning, disinfection, sterilization as in the CSSD, dialysis units, etc.). The quality standards for water in the hospital setting are not uniform. For example the final rinse cycle of washer-disinfectors of CSSD and the steam generators of the autoclave require water of very low TDS, whereas relatively high TDS water with satisfactory microbiological quality is acceptable for drinking or for general applications. [1],[2],[4] Similarly, the need for chlorination of water arises due to microbial contamination occurring within any part of the pipeline from generation to distribution [Figure 1], and could be perpetuated due to colonization of water lines by environmental organisms such as Pseudomonas and Legionella. Adequate chlorination may therefore be required as a reactive or a regular measure to ensure microbiological safety. Bacterial contamination of BDW and hospital mains water has been reported previously from various countries in the developed and the developing world including India, resulting in outbreaks of infection, and spread of antibiotic resistant and difficult to treat infections. [5],[6],[7],[8],[9],[10] Tata Medical Center being an oncology and BMT center has a significant number of patients who are immunocompromized due to disease, chemotherapy or radiotherapy. Providing microbiologically safe water to the patients, care providers and the staff is of paramount importance. It is hoped that the examples cited would help in highlighting the importance of this very basic aspect of patient and staff safety and infection control in the hospital setting.
Figure 1: Water circuit diagram at Tata Medical Center. Commonly used points of water quality assessments have been showed with a star mark. Note: (a) The positi on of the dummy filters is variable; (b) dashed border of boxes indicate proposed changes

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   Conclusion Top

Relatively inexpensive and simple technology can have a high impact in hospital infection control. Regular assessment of water quality is one of them. Microbes present in water pose a significant health risk to patients and care providers. Ensuring water supply of adequate quality and quantity is essential for health. In addition, water of specific standards is required for surgical instrument cleaning, disinfection and sterilization. Investing and maintaining water of good quality is worthwhile since it is a fundamental step in infection prevention.

   References Top

World Health Organization. Guidelines for Drinking-Water Quality. 3 rd ed. Geneva: World Health Organization; 2008.  Back to cited text no. 1
Health Protection Agency. The Microbiological Examination of Water Samples Issue No: 2 Issue Date: 06.12.05 Issued by: Standards Unit, Evaluations & Standards Laboratory. Reference no: QSOP 57i2. UK: Health Protection Agency; 2005.  Back to cited text no. 2
How to measure chlorine residual in water. World Health Organization. Technical Note No. 11, 2005.  Back to cited text no. 3
Department of Health. Choice Framework for local Policy and Procedures 01-01 - Management and decontamination of surgical instruments (medical devices) used in acute care. Part D: Washer-disinfectors. Crown copyright; 2013.  Back to cited text no. 4
Fujikawa H, Wauke T, Kusunoki J, Noguchi Y, Takahashi Y, Ohta K, et al. Contamination of microbial foreign bodies in bottled mineral water in Tokyo, Japan. J Appl Microbiol 1997;82:287-91.  Back to cited text no. 5
Jeena MI, Deepa P, Mujeeb Rahiman KM, Shanthi RT, Hatha AA. Risk assessment of heterotrophic bacteria from bottled drinking water sold in Indian markets. Int J Hyg Environ Health 2006;209:191-6.  Back to cited text no. 6
Shin GA, Sobsey MD. Inactivation of norovirus by chlorine disinfection of water. Water Res 2008;42:4562-8.  Back to cited text no. 7
Trautmann M, Halder S, Hoegel J, Royer H, Haller M. Point-of-use water filtration reduces endemic Pseudomonas aeruginosa infections on a surgical intensive care unit. Am J Infect Control 2008;36:421-9.  Back to cited text no. 8
Trautmann M, Lepper PM, Haller M. Ecology of Pseudomonas aeruginosa in the intensive care unit and the evolving role of water outlets as a reservoir of the organism. Am J Infect Control 2005;33:S41-9.  Back to cited text no. 9
Wong V, Levi K, Baddal B, Turton J, Boswell TC. Spread of Pseudomonas fluorescens due to contaminated drinking water in a bone marrow transplant unit. J Clin Microbiol 2011;49:2093-6.  Back to cited text no. 10

Correspondence Address:
Sanjay Bhattacharya
Tata Medical Center, South Lab, 14 Major Arterial Road (E-W), New Town, Rajarhat, Kolkata - 700 156, West Bengal
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0377-4929.138745

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