Water purification

Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water.

Contaminants

Aside from sediment, contaminants typically found in non-purified water are:

• Protozoa
  • Cryptosporidium
  • Giardia lamblia
• Bacteria
  • E. coli
  • Salmonella
  • Campylobacter
  • Shigella
  • (many others)
• Viruses
  • Hepatitis A
  • Enterovirus
  • Norovirus
  • Rotavirus
  • (many others)

Cryptosporidium

Potential health effects from ingestion of water contaminated with Cryptosporidium are:

• Gastrointestinal illness (for example, diarrhea, vomiting, cramps).

Sources of Cryptosporidium in drinking water are:

• Human and animal fecal waste.

Methods that are effective in removing Cryptosporidium from water are:

• Boiling (rolling boil for 1 minute) - very high effectiveness;
• Filtration - high effectiveness when using an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter);

Methods that are not sufficiently effective in removing Cryptosporidium:

• Disinfection with iodine or chlorine - not effective;
• Disinfection with chlorine dioxide - low to moderate effectiveness;

Combination filtration and disinfection has a very high effectiveness in removing and killing Cryptosporidium when used with chlorine dioxide and an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter).

Giardia lamblia

Also known as Giardia intestinalis.

Potential health effects from ingestion of water contaminated with Giardia are:

• Gastrointestinal illness (for example, diarrhea, vomiting, cramps).

Sources of Giardia in drinking water are:

• Human and animal fecal waste.

Methods that are effective in removing Giardia:

• Boiling (Rolling boil for 1 minute) - very high effectiveness;
• Disinfection with chlorine dioxide - high effectiveness;
• Filtration- high effectiveness when using an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter);

Methods that are not sufficiently effective in removing Giardia:

• Disinfection with iodine or chlorine - low to moderate effectiveness;

Combination filtration and disinfection has a very high effectiveness in removing and killing Giardia when used with chlorine dioxide and an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter).

Bacteria

Potential health effects from ingestion of water contaminated with bacteria are:

• Gastrointestinal illness (for example, diarrhea, vomiting, cramps).

Sources of bacteria in drinking water are:

• Human and animal fecal waste.

Methods that are effective in removing bacteria:

• Boiling (Rolling boil for 1 minute) - very high effectiveness;
• Disinfection with iodine or chlorine - high effectiveness;
• Disinfection with chlorine dioxide - high effectiveness;
• Filtration - moderate effectiveness when using an absolute less than or equal to 0.3 micron filter;

Combination filtration and disinfection has a very high effectiveness in removing and killing bacteria when used with iodine, chlorine, or chlorine dioxide and an absolute less than or equal to 0.3 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter).

Viruses

Potential health effects from ingestion of water contaminated with viruses are:

• Gastrointestinal illness (for example, diarrhea, vomiting, cramps), hepatitis, meningitis.

Sources of viruses in drinking water are:

• Human and animal fecal waste.

Methods that are effective at removing viruses:

• Boiling (Rolling boil for 1 minute minimum) - very high effectiveness;
• Disinfection with iodine, chlorine, or chlorine dioxide - high effectiveness;

Methods that are not effective at removing viruses:

• Filtration- not effective;