Water Properties and Safety Quiz

Water Properties

• Water is a chemical compound of two hydrogen atoms and one oxygen atom.
• Water makes up most of bodies and food.
• Engineers aim to help clients conserve water while maintaining optimal interior environments.
• Water effectively absorbs and releases heat during evaporation.
• Water is used in cooling systems (e.g., sprays, evaporative coolers, cooling towers) for buildings.
• Water also offers fire protection.

General Properties of Water

• Water level: takes the shape of its container to the limit of volume; tends to level out.
• Mass: the amount of matter in a body; constant regardless of location in the universe.
• Force: changes rest or uniform motion of a body.
• Pressure: force per unit area.
• Head: vertical distance from liquid's surface to point of pressure measurement.
• Capillarity: spontaneous movement up or down narrow tubes/pipes due to molecular attraction differences at the boundary between water and pipe.

Water Safety

• Physical Properties:
  • Turbidity
  • Color changes
  • Unpleasant taste/odor
• Chemical Characteristics:
  • pH
  • Presence of toxic substances (lead, arsenic, nitrates, chlorides, copper, iron, sulfates, zinc, sodium)

Chemical Characteristics: Specifics

• Lead: poses greatest threat to infants/young children (nervous system development); adults can experience kidney issues or high blood pressure.
• Arsenic: naturally found in some water sources; causes symptoms like dry coughs, burning hands/feet, and elevated cancer risks (lung, skin, bladder).
• Nitrates: cause "blue baby" syndrome in infants.
• Chlorides: affect the taste of groundwater.
• Copper: gives water an undesirable taste.
• Iron: produces red, brown, or yellow color in water; causes stains on laundry; harmless to health.
• Sulfates: natural laxative.
• Zinc: no health risk; produces unpleasant taste.
• Sodium: high levels can be dangerous for people with heart, kidney, or circulation problems; some water softeners increase sodium levels.

Biological and Radiological Characteristics

• Biological: Bacteria, Protozoa, Viruses
• Radiological: contamination from mining, industrial radioactive materials, power plants, military installations.

Water Quality Problems and Solutions

• Problem: Turbidity
  • Cause: Silt/suspended matter in surface flow
  • Effect: Discoloration, bad taste, minor health concerns
  • Solution: Filtration
• Problem: Color
  • Cause: Presence of iron/magnesium
  • Effect: Discoloration on fixtures/laundry
  • Solution: Precipitation by oxidation filter
• Problem: Taste
  • Cause: Algae, decomposing organic matter, dissolved gases, phenolic substances
  • Effect: Bad taste
  • Solution: Water treatment process
• Problem: Odor
  • Cause: Contaminants
  • Effect: Bad odor
  • Solution: Water treatment process
• Problem: Hardness
  • Cause: Calcium and magnesium carbonates and bicarbonates, calcium and magnesium sulfate and chloride
  • Effect: Clogging of pipes, impairment of laundry/food preparation, reduction of thermal efficiency, restriction of flow
  • Solution: Boiling (carbonate hardness), chemical precipitation (sulfate/chloride hardness) use of water softeners (zeolite)
• Problem: Pollution (includes pathogen bacteria)
  • Cause: Organic matter from sewage
  • Effect: Disease
  • Solution: Chlorination

Water Origin and Cycle

• Water amount is finite.
• Distribution: 70% is oceans and seas (Saltwater = 67%; Freshwater = 3% — 2% frozen; 1% other);
• Hydrologic Cycle: The Earth receives solar energy, which drives water evaporation and precipitation to constantly circulate water through the cycle.
  • Main loops: Surface runoff, Evapotranspiration, Groundwater
  • Processes within loop: Water enters storm drain, sewage, improvement of surface/groundwater, absorption into soil.

Water Supply Systems

• Source: Precipitation, Runoff, Groundwater (sinks into soil, fills open spaces)
• Types: Groundwater, Rainwater - Rainwater = earliest agrarian societies' source/most accessible and pure; collects underground; forms springs/lakes/swamps; major concerns are pollutants from storm drains and sewage contamination.
  • Groundwater = reliable source of water; deep wells are expensive, but filtering of impurities during travel through soil and rock; potentially contains dissolved minerals.
  • Wells
    • Types: Dug, Bored, driven, Drilled (percussion/standard, truck-mounted drilling, and Jetting)
    • Quality/maintenance aspects: Dug wells range from 0.90 to 6 meters in diameter, carved through the upper soil, sides need masonry or concrete to prevent curving in. Impervious to a depth of minimum 3 meters
• Piping Systems in Public Infrastructure - Water mains transport water for public use, directed to buildings via service pipes. - Water meters record water usage, and control valves shut off water in emergencies or if bills are unpaid. - Distribution pipes supply water to fixtures; Fixture branches connect several fixtures. - Fixture Supplies link fixtures to branch/main pipes.

Hard Water

• Results from calcium salts, which can build up inside pipes (scaling) and convert soap to scum.
• A water softener controls hard water.

Municipal Water Supply Systems

• Water pressure in mains offsets friction and gravity.
• Pressure is usually 345 kPa.
• Pipe sizes alter pressure inside buildings; bigger pipes decrease pressure.
• Pressure at fixtures is 35–204 kPa; too much pressure (splashing), too little pressure (dribbling).
• Pressure reducers regulate fixtures.

Water Supply Systems in the Philippines

• Levels (DOH standards):
  • Level I: hand pumps, shallow wells, rainwater collectors for point-source gathering of water
  • Level II: bored wells and spring systems for communal water points
  • Level III: piped water supply via waterworks networks, with private connections.
• Sources: Rivers, lakes, and 1,830 sq km of watershed.
• Critical areas: NCR, Central Luzon, Southern Tagalog, Central Visayas.
• Water sources: Angat, Ipo, and La Mesa Dams; processed through treatment plants.
• Management Agencies: NWRB, PTFWRDM, DPWH, DOH, DENR, DILG, NPC, NIA, BSWM, MWSS, and LWUA.