1. MODULE 23: Management of Healthcare Wastewater
The training modules are part of the United Nations Development Programme-supported, Global Environment Facility-funded Project on Healthcare Waste, in cooperation with the World Health Organization and Health Care Without Harm. The modules were completed in 2012 by Preethi Pratap, PhD, and Leslie Nickels, PhD, of the University of Illinois at Chicago School of Public Health, and Jorge Emmanuel, PhD, Chief Technical Advisor of the UNDP GEF Project, with input from Yves Chartier (WHO), Mohammad-Ali Hamandi, MPH, Ashley Iwanaga, MPH, Glenn McRae, PhD, Megha Rathi, PhD, Ruth Stringer (Health Care Without Harm), and Emily Warren, MSES.
This module may be used as a resource to improve healthcare waste management. The module is copyrighted but may be reproduced in its original unaltered form without permission for advocacy, campaigning and teaching purposes. Reproduction and distribution for commercial resale is strictly prohibited. UNDP GEF does not warrant that the information contained in this document is complete and correct and shall not be liable for any damages incurred as a result of its use.

2. Module Overview
Describe sources of wastewater in a healthcare facility
Describe characteristics and hazards associated with wastewater from healthcare facilities
Describe treatment and disposal options for wastewater from healthcare facilities

3. Learning Objectives
Identify sources and hazards of wastewater in your healthcare facility
Identify appropriate methods collection, treatment and disposal of wastewater
Describe your facility’s wastewater management program
Discuss possible options to improve management of wastewater in your facility
Participant Assignment Prior to Session:
Each participant obtains information about what happens to the wastewater from his or her healthcare facility.

4. Healthcare Wastewater
Any water adversely affected in quality during provision of healthcare services
It is mainly liquid waste
containing some solids disposed by staff and patients, or
during other healthcare-related processes, such as cooking, cleaning or laundry

5. Categories of Healthcare Wastewater
Blackwater (sewage) is heavily polluted wastewater containing high concentrations of:
faecal matter and urine
food residues
toxic chemicals
Greywater (sullage) is low polluted wastewater with residues from:
– washing, bathing, laboratory processes, laundry, or technical processes such as cooling water or the rinsing of X-ray films
Stormwater is technically not wastewater but consists of rainfall collected on hospital roofs, grounds, and paved surfaces
- It may seep into groundwater, or be used for irrigation of hospital grounds or toilet flushing.

6. Sources of Healthcare Wastewater
Administration and wards
Kitchen
Laundry
Operating rooms and ICU
Laboratories
Radiology
Haemodialysis
Dental departments
Toilets
Engineering and maintenance department
Runoff from paved areas,
Administration and wards generate waste water, comparable to domestic wastewater. The urine of patients from some wards (surgery wards, oncology, infectious disease ward, etc.) might contain higher amounts of antibiotics, cytotoxic and X-ray contrast media. Additionally higher amount of disinfectants can occur.
Kitchen of hospitals often generate the most polluted wastewater stream as it contains leftovers, waste from food processing and high rates of disinfectants and detergents. Starch, grease, oil and the high organic content might create problems during the waste water management.
The Laundry is the place with the highest quantity of produced grey waster. The waste water often is hot, has a high pH (alkaline) and might content high rate of phosphate and AOX (absorbable organically bound halogens) if chlorine based disinfectants are used.
Operating theatre and ICU generate a wastewater with higher contents of disinfectants (glutaraldehyde), detergents and pharmaceuticals. Additionally the organic content can be high due to the disposal of body fluids and rinsing liquids (suction containers).
Laboratories are a possible source for chemicals in the wastewater stream. Of special relevance are halogenated and organic solvents, colourants from the histology and haematology (gram staining), cyanides (haematology) and formaldehyde and xylem (pathology).
The Radiology department is the main generator of photochemical (developing and fixing solutions) containing waste water and potentially contaminated rinsing water.
Haemodialysis requires the disinfection of the dialysers and sometimes the used filters. Accordingly the disinfectant content in the waste water can be high.
Dental departments might contaminate the wastewater with mercury (Amalgam) if no amalgam separators are installed

7. Health and Environmental Hazards of Healthcare Wastewater
Wastewater contaminants:
Important chemicals in hospital wastewater include anesthetics, disinfectants (formaldehyde, glutaraldehyde), chemicals from laboratory activities, photochemical solutions (hydroquinone), and X-ray contrast media containing absorbable organohalogen compounds (AOX)
Mercury from dental amalgams or lab chemicals
Excessive nutrients and nitrates
Pharmaceuticals, including antibiotics
Radioactive wastes
Infectious agents, including bacteria, viruses and parasites

8. Health and Environmental Hazards of Wastewater
Wastewater is potentially infectious
Some healthcare facilities in low-income areas have no sewer systems
Some sewers of healthcare facilities are not watertight, and wastewater can leak into groundwater
Improper wastewater management, collection, treatment, and disposal may result in the pollution of local drinking water sources, or the contamination of natural resources
As domestic wastewater is considered as potential infectious, also wastewater from health care facilities must be considered as potential infectious and pre-cautions must be taken.
the wastewater might contain chemicals, pharmaceutical and contagious biological agents and might even contain radioisotopes. Sewers of health care establishments are often not watertight and a significant part of the wastewater is leaking into the groundwater. Often hospitals are not connected to efficient working sewage treatment plants, and sometimes municipal sewer networks may not even exist.

9. Health and Environmental Hazards of Wastewater
Environmental implications
Excessive nutrients cause biological degradation in groundwater, lakes and rivers by using up oxygen (eutrophication) resulting in algal blooms and biotoxins
Pharmaceuticals in water may act as endocrine disruptors
Antibiotics could result in antibiotic-resistant pathogens
Mercury and heavy metal poisoning
Water-borne disease outbreaks in communities
Campylobacterosis, cholera, Hepatitis A and E, schistosomiasis, and typhoid fever
Vector-borne diseases and parasites
Dengue fever, malaria, roundworms
Improper management, collection, treatment and disposal of wastewater and/or sludge will result in the pollution of local water sources with pathogens. This can cause numerous water borne diseases and vector borne diseases (e.g. malaria and dengue fever by providing breeding place to the vectors) and favours the spreading of parasites (e.g. roundworms or Ascaris lumbricoidesNitrate in the groundwater from untreated wastewater can result in Methaemoglobinaemia. Waterborne diseases are today one of the big thread to human life, especially in developing countries.
Eutrophication = oxygen depletion

10. Wastewater Management
Basic underlying principle of effective wastewater management
Strictly limit the discharge of hazardous liquids to sewers.
Segregation, waste minimization, and safe storage are just as important for liquid wastes as for solid wastes
Chemical and pharmaceutical wastes—such as photographic chemicals, aldehydes, colorants and antibiotics—should not be discharged directly into the sewer drain

11. Wastewater Management
Two traditional collection arrangements:
“Central system” of sewage pipes bringing wastewater from throughout the facility to a central underground location for treatment or disposal
“De-centralized system” wherein pipes from some medical areas pass wastewater to septic tanks or cesspits (not a preferred approach)
segregation, minimization of the generation of liquid waste and safe storage of hazardous liquid waste is of importance. Further information about minimization can be found in Chapter 6.
A system of sewer pipes (sewerage) shall collect sewage in a health care establishment and takes it for treatment or disposal (central system). The de-central collection and treatment is not recommended. Only where a main sewerage system has not been provided, sewage may be collected from the wards by pipes into septic tanks or cesspits, where it may be treated or collected in vehicles and taken for treatment or disposal (de-central system).
The separate collection of grey- and blackwater is normally not recommended, as this might result in hydraulically problems (blockages) during the collection of the blackwater. The separating of brown water (faeces water) and yellow water (urine and water) might make sense if a new sewage system is planned and the sewerage system will be dimensioned on the water quantity.

12. Wastewater Management
Recommended set-up
Construction of two separate collection systems
Sewage system for wastewater
Stormwater system for rainwater, which can be used for gardens, toilet flushing or washing of paved areas
Manholes to allow access for maintenance every 50 meters or less
Watertight sewage pipes and manholes
Pre-treatment to reduce or eliminate contaminants in non-domestic wastewater, or in altering its nature before discharging it into the sewer
segregation, minimization of the generation of liquid waste and safe storage of hazardous liquid waste is of importance. Further information about minimization can be found in Chapter 6.
A system of sewer pipes (sewerage) shall collect sewage in a health care establishment and takes it for treatment or disposal (central system). The de-central collection and treatment is not recommended. Only where a main sewerage system has not been provided, sewage may be collected from the wards by pipes into septic tanks or cesspits, where it may be treated or collected in vehicles and taken for treatment or disposal (de-central system).
The separate collection of grey- and blackwater is normally not recommended, as this might result in hydraulically problems (blockages) during the collection of the blackwater. The separating of brown water (faeces water) and yellow water (urine and water) might make sense if a new sewage system is planned and the sewerage system will be dimensioned on the water quantity.

13. Pre-Treatment of Hazardous Liquids
Pre-treatment for the medical laboratory (recommended) includes acid-base neutralization, filtration and sedimentation, or autoclaving
Pre-treatment for feaces or vomit during an outbreak such as cholera involves decontamination with lime milk (hydrated calcium oxide or calcium hydroxide) – ratio of 1:2 for stool and vomit with lime for 6 hours minimum; ratio of 1:1 for urine with lime for 2 hours minimum.
Blood can be discharged in the sewer (using PPE to protect from blood splatter) if a risk assessment shows that the organic loading does not require pre-treatment. Otherwise, blood can be pre-treated by a thermal method or disposed directly into a septic tank if safety measure are used. NOTE: 5% hypochlorite is not effective for high organic loads like blood.
Collected body fluids, small quantities of blood and rinsing liquids from the OT and the ICU can be discharged in the sewer system without pre-treatment if the patient is not suffering on an infectious disease, otherwise it shall be first disinfected, preferably with a thermal method. Larger amount of blood should not be emptied in the sewer as it will result in blockages and shall be disposed of as pathological waste. However, blood can be disposed of directly to a septic tank system (see section 9.6.2) if safety measures are followed.

14. Pre-treatment of Hazardous Liquids
Pre-treatment for the dental department entails installing amalgam separators in sinks, especially by patient treatment chairs; the separated mercury waste must be safely stored.
Pre-treatment for the radiotherapy department involves separate collection of radioactive wastewater (e.g. urine of patients from the thyroid treatment) and storage for decay in a secured die-away basin until background concentrations have decreased; after the required storage time, the wastewater can be disposed of in the sewer system.
Pre-treatment for kitchens entails a grease trap to remove grease, oil, and other floating materials

15. Liquids That Do Not Require Pre-Treatment
Non-hazardous chemicals such as syrups, vitamins, or eye drops
Small quantities of blood and rinsing liquids from surgical theaters can be discharged in the sewer system without pre-treatment
Large quantities of blood may require pre-treatment if it is indicated by a risk assessment.

16. Healthcare Sewage System
The preferred method is to connect the healthcare sewage system to the municipal sewage system and to discharge healthcare wastewater after adequate pre- treatment to municipal sewage if the municipal sewage treatment plant meets the following minimum requirements:
Use of primary, secondary and tertiary treatment
Removal of >95% of bacteria
Treatment of sewage sludge to destroy helminth eggs to < 1 egg per liter
Compliance with local regulatory requirements

17. Healthcare Sewage System
If no municipal sewage system exists, or
If the municipal sewage system does not meet basic requirements, or
If the area experiences epidemics of enteric diseases or endemic intestinal helminthiasis
The recommended option is on-site wastewater treatment
The objective is to treat effluent so it is suitable for reuse or discharge into the environment, usually into surface water
Typically, wastewater treatment involves three stages. The first stage is the removal of solids, which are separated by sedimentation (primary treatment). Then dissolved biological matter is progressively converted into a solid mass by using indigenous, water-borne bacteria. Some ingredients will be eliminated by adsorption to the sludge, which will separated by sedimentation afterwards (secondary treatment). At the end, solid and liquid materials are separated and the treated water may be further treated to remove suspended solids, phosphates or other chemical contaminants; or it may be disinfected (tertiary treatment).
Chlorine is commonly used as the disinfectant in tertiary treatment of healthcare wastewater. Its effectiveness will depend upon a number of water quality parameters of the water being treated (pH, turbidity, etc.). It will only be effective if the wastewater contains less than 10mg/L of suspended organic matter.

18. On-Site Wastewater Treatment for Large Healthcare Facilities
3 Stages for efficient on-site treatment:
Primary treatment: to remove of heavy solids
Secondary treatment: to remove dissolved and suspended biological matter using indigenous bacteria
Tertiary treatment: to further treat the wastewater for the purpose of reducing pathogens, suspended solids, excessive phosphorus and nitrogen nutrients, and/or chemical contaminants
Typically, wastewater treatment involves three stages. The first stage is the removal of solids, which are separated by sedimentation (primary treatment). Then dissolved biological matter is progressively converted into a solid mass by using indigenous, water-borne bacteria. Some ingredients will be eliminated by adsorption to the sludge, which will separated by sedimentation afterwards (secondary treatment). At the end, solid and liquid materials are separated and the treated water may be further treated to remove suspended solids, phosphates or other chemical contaminants; or it may be disinfected (tertiary treatment).
Chlorine is commonly used as the disinfectant in tertiary treatment of healthcare wastewater. Its effectiveness will depend upon a number of water quality parameters of the water being treated (pH, turbidity, etc.). It will only be effective if the wastewater contains less than 10mg/L of suspended organic matter.

19. Example of On-Site Wastewater Treatment for a Large Healthcare Facility
PRIMARY TREATMENT
Healthcare sewage
Equalization Tank
Aeration Tank
Bar Screen
Grit Chamber
SECONDARY TREATMENT
filtrate
filtrate
activated sludge
Sludge dewatering press
Aerobic digester
Thickener
Clarifier
SLUDGE TREATMENT
Filter
(pressed sand or carbon filter)
Sludge cake
TERTIARY TREATMENT
Composting, landfilling, land reclamation, silviculture, or other uses (depending on levels of heavy metals, toxic organics and pathogens)
Chlorine or UV disinfection
Treated wastewater

20. On-Site Wastewater Treatment
On-site wastewater treatment produces sludge which contains high concentrations of pathogens
Options for treatment of sludge:
Anaerobic digestion
Aerobic digestion
Composting
Reed beds
On-site treatment of hospital sewage will produce a sludge that contains high concentrations of helminths and other pathogens and therefore must be treated prior disposal. The most common treatment options include anaerobic digestion, aerobic digestion, and composting.
Horizontal reed bed

21. On-Site Wastewater Treatment
Common parameters for monitoring the effluent quality
Temperature pH
Total suspended solids
BOD5 (biochemical oxygen demand for 5 days at 20ºC)
Chemical oxygen demand
Nitrate
Total phosphorus
E. coli concentration

22. Minimum Approach to Wastewater Management
Sufficient toilets (WHO 2008)
1 toilet per 20 users for inpatient settings
4 toilets per outpatient setting (per setting: 1 each for male and female staff, 1 for female patients, 1 for male patients).
toilets should ideally be connected to a sewerage system.

23. Minimum Approach to Wastewater Management
Two-chamber septic tank with a lined soakaway

24. Minimum Approach to a Liquid Hazardous Waste Management System
Body-fluids and the contents of suction systems from highly infectious patients (e.g., cholera)
Should be thermally treated (e.g. in a waste treatment autoclave) and then discharged via the drain, or
Disinfected with hydrated calcium oxide for several hours before being discharged via the drain
Stool, vomit and mucus from infectious patients should be separately collected
thermally treated prior to disposal or treatment with hydrated calcium oxide for several hours

25. Minimum Approach to a Liquid Hazardous Waste Management System
Hazardous pharmaceuticals and chemicals should never be disposed of via the wastewater system.
Liquid laboratory hazardous waste (colorants, formalin) should be separately collected, mixed with an absorbent (e.g., saw dust), and immobilized or encapsulated.
Chlorine based disinfectants should be diluted to reach a concentration of <0.5% active chlorine.
Liquid pharmaceuticals in vials (but not cytotoxic materials) could be crushed in a closed bucket, mixed with sawdust and encapsulated
Glutaraldehyde should be stored after use, neutralized with glycine, and slowly disposed of via a soak away pit

26. Minimum Approach to a Liquid Hazardous Waste Management System
Options for management of expired blood bags:
PPE and other precautions should be taken to protect against blood splatter
Dispose of at a controlled sanitary landfill, or
Treat in a high temperature incinerator (1100 0C) , or
Treat in an autoclave with a special liquid treatment cycle, or
Bury unopened in a protected pit within the healthcare facility or other secure location

27. New Technology
Ask participants if they are aware of any new technology available in their country.

28. National and Local Regulations Related to Wastewater Discharges
Add information on any national and/or local regulations

29. Discussion
What are some major sources of wastewater within your healthcare facility? What about minor sources?
What are some public and environmental health hazards associated with healthcare wastewater? Are there certain hazards you perceive within your own facility?
What happens to the wastewater in your facility after it goes down the drain? What procedures does your facility use in the overall management of wastewater and other hazardous liquid wastes? What safety measures are in place? Does the facility use waste minimization techniques to limit the amount of discharged liquids?
Instructor: if this is a large facility- then they may have a wastewater treatment facility on-site.
If they don’t then discuss what pre-treatment methods are used before discharging waste waters into the main municipal sewers.
If they have septic tanks or cess-pits then discuss what the issues are currently. Do they perceive any hazards?

30. Discussion
Does your facility have wastewater treatment on- site? If not, what pre-treatment methods are used, if any, before release to the main municipal sewer system? Are septic tanks and cesspools used?
What are the country/region-specific regulations and guidelines for managing wastewater (segregation, treatment, disposal, etc.) from healthcare facilities?
Discuss some ways to minimize wastewater in your facility.