water quality

• Water Action Decade, 2018-2028: Averting a global water crisis
• 4 billion people lack access to basic sanitation services
• Floods and other water-related disasters account for 70 per cent of all deaths related to natural disasters
• Access to safe drinking water and sanitation is a basic human rights of nations; i.e. water is a right not a privilege
• Determinants of Community Water

  • Quantity determinants
  • Quality determinants
  • Economical determinants
• Quantity Determinants


  • Water demand
  • Water supply / person (L/day)
• Domestic (BWR) Use


  Basic Water Requirements (BWR) 50L/day/person minimum, 20L/day/person in emergency situation
• To conduct a community water supply project, quantity demands need to be assessed. Studies must be conducted to estimate sustainability of the water source.
• Quality Determinants

  • Improper disposal of domestic wastewater (Sewage)
  • Surface washings drainage into surface water or reaching ground water aquifer through sink holes
  • Contamination of water reservoirs
  • Agriculture run-offs into surface and groundwater
  • Cross contamination (water pipes and wastewater collection network)
  • Improper disposal of industrial wastes into surface and ground water
• Major Physical Characteristics

  • Temperature
  • Water hardness
  • Taste and Odor
  • Color
  • Turbidity (cloudiness or haziness of a fluid)
  • Dissolved Solids
• Water hardness

  The amount of dissolved calcium and magnesium in the water. Hard water is high in dissolved minerals, largely calcium and magnesium.
• Major Chemical characteristics


  • Micro - elements: Calcium, Magnesium, Chloride, Sulfate, Phosphate, Iron
• Major Physical Characteristics of water

  • Temperature
  • Water hardness
  • Taste and Odor
  • Color
  • Turbidity (cloudiness or haziness of a fluid)
  • Dissolved Solids
• Water hardness


  The amount of dissolved calcium and magnesium in the water
• Hard water is high in dissolved minerals, largely calcium and magnesium
• In hard water, soap reacts with the calcium (which is relatively high in hard water) to form "soap scum"
• When using hard water, more soap or detergent is needed to get things clean, be it your hands, hair, or your laundry
• The presence of pathogenic microorganisms is critical, although they do not occur naturally in aquatic environments they are transmitted by natural water systems
• Biological indicators of contamination

  • Fecal Coliform Bacteria (E. coli)
  • Fecal Streptococci (Strep. faecalis)
• Certain rock types have naturally occurring trace amounts of "mildly radioactive" elements
• These radioactive contaminants may accumulate in drinking water sources at levels of concern
• Industrial radioactive reactors may also form an industrials radiological contaminants to water
• Economic Considerations for a successful community water supply project


  • Analyze costs of utilizing safe potable water sources
  • Cost of collection and conveyance (transfer/distribution)
  • Cost of storage facilities
  • Cost of pumping stations
  • Cost of desired treatment processes
  • Ensure acceptance of project by community
• Hydrological Cycle


  Pumping system, driven by the sun, which moves fresh water from the oceans to landmasses then returns it to the ocean
• Treatment of Domestic Water Supplies

  • Screening
  • Coagulation
  • Settling/Sedimentation/precipitation
  • Filtration
  • Disinfection
• Determinants of Community Water Programs


  • Public acceptance of the final plan
  • Community Awareness
  • Community Mobilization
  • Developing Community Consensus and Commitment
  • Plan, Monitor, and Construct
  • Operation and Maintenance
  • Community Assessment and Evaluation