The Multi-Barrier Approach to Safe Water
* water hygiene
Safe Storage
Treatment
Disinfection Filtration Sedimentation
Each step in the process incrementally reduces risks.
A multi-barrier approach is the best way to reduce the risk of drinking unsafe water.
50%
More often than not, people focus on a particular technology that is directed towards one step, rather than considering the whole water treatment process. The entire process is essential to provide the best water quality possible for improved health.
What is the best technology? There is no “silver bullet” technology. Context-appropriate solutions take into account the local water situation, communities’ needs and preferences, economic factors, availability of local skills, and local or national regulations. It’s not just about the technology - it’s mostly how it is implemented. We need to understand what has or hasn't worked and why.
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Households do a lot of work to collect, transport and treat their drinking water. After the water is treated, it needs to be handled and stored properly to keep it safe. Recontamination of safe drinking water is a significant issue.
Household water treatment (also called point of use) follows the same basic water treatment process as community systems. The main difference is the scale of the systems. HWTS is primarily focused on removing pathogens - the biggest health threat.
sanitation
100% 90%
to inactivate
any remaining pathogens
to remove
smaller particles and often >90% of
pathogens
to remove
larger particles and up to >50% of
pathogens
Source Protection
Household Water Treatment & Safe Storage (HWTS)
DISINFECT FILTER
SEDIMENT
Safe Storage
Treatment
Hygiene Hygiene refers to the conditions and practices that help to maintain health and prevent the spread of diseases.
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STEPS to improve water quality
Hygiene promotion: Systematic approaches to encourage the widespread adoption of safe hygiene practices to reduce diarrheal and other water- and sanitation-related diseases. There are many factors that motivate changes in behaviour. These may or may not be related to knowledge of the health consequences of poor hygiene. Individual behaviour and a hygienic environment
are important to protect individual health.
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Sanitation is the safe management of human excreta. The objective is to protect public health by protecting the water source, preventing excreta from contaminating the environment and breaking the cycle of disease.
Sanitation
Sanitation system: Also called a sanitation chain, value chain or sanitation service chain. A collection of technologies that deals with human excreta, from the time it is generated until it is used or disposed of safely. It is a general term for both sewered and non-sewered sanitation systems.
User Interface
Excreta Storage
Treatment Use or
Disposal
Treatment Sewer
Fecal Sludge Management (FSM)
Use or Disposal
Sewered Sanitation System
Fecal sludge: Excreta from an on-site sanitation technology that may also contain used water, anal cleansing materials, and solid waste.
Treatment: Any process to inactivate pathogens, stabilize, dewater, or manage nutrients in fecal sludge.
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On-site sanitation technology: Included in the first two components of a sanitation system: user interface and excreta storage. Excreta is collected and stored where it is produced (for example, a pit latrine, septic tank, aqua privy, and non-sewered public toilets).
Fecal sludge management: Includes the emptying, transport, treatment, and safe use or disposal of fecal sludge from an on-site sanitation technology.
Online WASH Resources Find more definitions at
cawst.org/WASHglossary
Find over 3,000 WASH education & training resources at
cawst.org/resources
Get support today from our Technical & Education Advisors at
References at cawst.org/miniWASHGuide
Emptying & Transport
Non-sewered system: Also called on-plot or on-site sanitation. A sanitation system in which excreta and used water are collected and stored on the location where it is produced. Often, the fecal sludge has to be transported off-site for treatment, use or disposal.
Non-Sewered Sanitation System
Wastewater: Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff (stormwater), and any sewer inflow (infiltration). Wastewater can be managed on-site or off-site. Wastewater managed off-site is often called sewage.
User Interface
Sewered system: Also called a sewer system, sewerage system, sewers, connected sanitation, and networked sanitation. A sanitation system that transports wastewater through a pipe network (like a simplified sewer or conventional sewer) to another location for treatment, use or discharge. This includes centralized systems and decentralized wastewater treatment systems.
Sanitation system illustrations by Bill and Melinda Gates Foundation (BMGF); CC by 2.0
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