What is ‘Excreta’?
Excreta refer to human waste, comprising both feces and urine. The methods of its disposal vary significantly based on cultural practices, economic conditions, water availability, and hygiene behaviors, such as the use of water or toilet paper for cleaning.
The Hazards of Improper Excreta Disposal
Improper disposal of excreta poses severe risks to public health and the environment. These include:
• Soil Contamination: Excreta can pollute the soil, rendering it unsafe for agriculture and other uses.
• Water Pollution: When excreta enter water sources, it contaminates them, leading to the spread of waterborne diseases.
• Food Contamination: Pathogens from excreta can transfer to food crops, especially when untreated human waste is used as fertilizer.
• Fly Breeding: Excreta serves as a breeding ground for houseflies, which act as vectors for disease transmission.
Excreta harbor harmful microorganisms that can re-enter the human body through contaminated food, water, or insects. These pathogens include:
• Viruses: Poliovirus, Hepatitis A virus, and those causing gastroenteritis.
• Bacteria: Vibrio cholerae (cholera), Salmonella typhi (typhoid), and Shigella (dysentery).
• Parasites: Roundworms, tapeworms, and pinworms.
Methods of Excreta Disposal
Various methods exist for the disposal of excreta, tailored to different settings, such as areas with or without sewer systems. Below, we explore these methods in detail.
Unsanitary Methods: Practices to Abandon
1. Open Defecation:
This practice is highly unsanitary and should only be considered in extreme emergencies, such as natural disasters. Even then, designated areas must be established far from water sources, food supplies, and human settlements to minimize health risks.
2. Service-Type Latrines (Conservancy System):
Historically, this system involved collecting excreta in buckets, which were then manually removed by workers and disposed of through burial or trenching. This method has been universally condemned and banned due to its unsanitary nature and social inequities. Key issues included:
• Disease Transmission: Exposure to untreated waste facilitated the spread of infections.
• Fly Infestation and Odor: The system attracted flies and produced intolerable smells.
• Exploitative Labor: It relied on manual labor, often under degrading and hazardous conditions.
- Recognizing its detrimental impact on public health and human dignity, this outdated practice has been banned.
The Path Forward: Hygienic and Sustainable Solutions
The Environmental Hygiene Committee (1949) advocated for the replacement of service-type latrines with hygienic ones. These systems ensure safe on-site disposal of excreta, even in the absence of sewer networks, thereby eliminating the need for manual handling and reducing health risks.
Non-Conservancy Systems: Sanitary Latrines
Sanitary latrines are hygienic solutions for excreta disposal that do not rely on manual handling or the outdated "conservancy system."
A ‘sanitary latrine’ is a toilet that effectively disposes of human waste in a way that prevents disease transmission and environmental contamination. Hence following criteria have to be met to call a latrine as ‘sanitary’:
1. Excreta should not contaminate any water source (ground-water or surface water)
2. Excreta should not pollute the surface soil
3. Excreta should not be accessible to flies and other vectors like rats, dogs, cattle, pigs etc.
4. Excreta should not be accessible to humans so that it is not a nuisance by either stink or nasty appearance
Sanitary latrines play a pivotal role in establishing what is known as the "sanitation barrier."
These latrines may need to be designed for various settings, including:
1. Unsewered Areas:
- In regions without access to sewer systems, sanitary latrines provide a safe and sustainable method for on-site excreta disposal. They prevent contamination of soil and water sources, ensuring public health and environmental safety.
2. Sewered Areas:
- Even in areas with sewer networks, sanitary latrines serve as an efficient and hygienic option. They can be connected to the sewer system, facilitating the safe transport and treatment of waste.
3. Temporary Situations:
- In temporary settings, such as construction sites, disaster relief camps, or outdoor events, sanitary latrines offer a practical and hygienic solution for waste management. They are easy to install, maintain, and remove as needed.
Unsewered Areas
When selecting an appropriate latrine for a particular situation, the following points should be considered:
• Availability of resources to be used.
• Affordability and social acceptability of the latrine.
• Availability of adequate land and space for future expansion.
• Repair and maintenance costs.
Non-service type or Sanitary Latrines
• Bore Hole Latrine
• Dug well Latrine
• Water seal Latrine
o PRAI
o RCA
• Sulabh sauchalaya
• Septic tank
• Aqua privy
Sewered areas
• All latrines drain into underground network of sewage pipes which drain into STP.
• In STP: Sewage undergoes primary treatment and then secondary Treatment followed by final disposal
Latrines suitable for camps and temporary use
• Shallow trench latrine
• Deep trench latrine
• Pit latrine
• Bore hole latrine
References:
• Park's Textbook of Preventive and Social Medicine. 26th ed. Jabalpur: M/S Banarsidas Bhanot; 2021. Environment and Health; p. 799-883.
• Park's Textbook of Preventive and Social Medicine. 27th ed. Jabalpur: M/S Banarsidas Bhanot; 2023. Environment and Health; p. 832-915.
• Bhalwar R. Textbook of Community Medicine. 5th ed. New Delhi: Wolters Kluwer; 2023. Chapter 8, Excreta Disposal; p. 89-101.
• Series 3, Sanitation; WHO website. Available at: https://apps.who.int/iris/bitstream/handle/10665/66334/WHO_EOS_96.4_2.p1... accessed on 28th March 2025
Excreta Disposal: https://ihatepsm.com/blog/proper-excreta-disposal-necessity-health-and-d...
Video on Sewage Treatment: https://youtu.be/M3iMq4-iFHg
Bore-Hole Latrine: https://ihatepsm.com/blog/bore-hole-latrine#google_vignette