Roofwater harvesting using slow sand filtration

Some common roofwater contaminants:
what to test for in harvested roofwater

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These are the tests that have already been done on the water from one of the systems referred to on this website: (the system we describe on this site with Filter 1 removes all of these 18 contaminants to beyond the requirments of the EPA for drinking water quality.)
  1. Coliform bacteria
  2. Arsenic
  3. Zinc
  4. Nitrites
  5. Nitrates
  6. Sodium
  7. Silver
  8. Barium
  9. Cadmium
  10. Selenium
  11. Chromium
  12. Mercury
  13. Lead
  14. Fluoride
  15. Total Petroleum Hydrocarbons sometimes called TPH
  16. Total Organic Carbon sometimes called TOC
  17. E Coli bacteria
  18. Fecal Coliform bacteria
At the very minimum do a test for coliform bacteria, and Arsenic. If there is any coliform bacteria present, it may indicate the presence of other very harmful bacteria. If Arsenic is present above the EPA limits of 10 parts per billion (.01 mg/L) the water is not safe.

The tests on Filter 4 for CHEMICAL CONTAMINANTS have NOT been done yet.

Other contaminants that may be present but have not been tested for in this research:
  • Asbestos
  • Copper
  • Tannins
  • Baylisascaris Procyonis (Raccoon roundworms)
  • Viruses (any type)
  • Industrial chemicals
Water can be contaminated by just about anything. This is only a list of contaminants that have been discovered in the study this site refers to. Do not drink or otherwise consume water from any of the sources or filters described on this website without first having it tested by someone who knows how to check for biological and/or chemical contaminants in water. The study includes information from 50 scholarly articles describing scientific studies on biological sand water filters; and 61 individual tests on water before and after being run through 7 different configurations of biological sand filters. All the water quality tests were performed by an EPA certified laboratory.

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