water treatment Potable water…water that is drinkable; safe for consumption Drinking water treatment is widespread in developed countries today However, developing countries lack safe drinking water…result in many deaths Developing countries also lack adequate sewage treatment

Drinking water treatment Reservoir or aquifer water is pumped to a facility where it is treated with chemicals to remove any particulate matter Water is then passed through filters of sand, gravel, and charcoal to further remove impurities Water is treated with chlorine &/or undergoes UV treatment for final disinfection

Waste water Water that people have used in some way Sewage Showers/sinks washing machines/dishwashers Manufacturing Industrial cleaning processes Storm water runoff

Septic systems Method of wastewater disposal in rural areas Separates solids from liquid Digests & store organic matter Clarified liquid is discharged into an underground drain/leach field & into surrounding soil Soil microorganisms degrade & decompose the septage

Municipal Wastewater treatment Routine in urban, densely populated areas in developed countries Primary & secondary treatment is required by US federal law

Primary treatment Physical removal of contaminants in settling tanks or clarifiers Approximately 60% of suspended solids are removed

Secondary treatment Biological process that involves wastewater proceeding to aeration basins Stirred & oxygenated Aerobic bacteria degrade the organic pollutants 90% suspended organic solids are removed

Tertiary (advanced) treatment Physical & chemical process of removing specific pollutants left in the water EX: removing specific toxic chemicals (heavy metals) from local industrial plants EX: excess nitrates from water contaminated with excess fertilizers Expensive process…occurs only in a few locations

Final stages Water treated with chlorine…ozone…or uv light to kill infectious agents Effluent piped into river or ocean

sludge solid material that is removed during the wastewater treatment process Partially dried on site then transported to local municipal incinerator or disposed of in a landfill May be used as fertilizer on croplands in areas where industrial & manufacturing byproducts are not present in wastewater