Methods of chlorine treatment:
Bleach: Ordinary household bleach (such as Clorox) in the US contains 5.25% sodium
hypochlorite (NaOCL) and can be used to purify water if it contains no other active ingredients,
scents, or colorings. Bleach is far from an ideal source due to its bulkiness (only 5% active
ingredient), and the instability over time of the chlorine content in bleach. Chlorine loss is farther
increased by agitation or exposure to air. One source claims chlorine loss from a 5% solution at
10% over 6 months if stored at 70° F. Nevertheless, this may be the only chemical means
available to purify water, and it is far better than nothing. Normal dosage is 8 drops (0.4 ml) per
gallon. Allow the treated water to sit for 30 min., and if there isn’t a slight chlorine smell, retreat.
Note: USP standard medicine droppers are designed to dispense 0.045-0.055 ml per drop. Use of
other solvents or some chemicals can change this. The dropper can be calibrated against a
graduated cylinder for greater accuracy.
Some small treatment plants in Africa produce their own sodium hypochlorite on site from the
electrolysis of brine. Power demands range from 1.7 to 4 kWh per lb. of NaOCL. 2 to 3.5 lbs. of
salt are needed for each pound of NaOCL. These units are fairly simple and are made in both the
US and the UK. Another system, designed for China, where the suitable raw materials were
mined or manufactured locally, used a reaction between salt, manganese dioxide, and sulfuric
acid to produce chlorine gas. The gas was then allowed to react with slaked lime to produce a
bleaching powder that could then be used to treat water. A heat source is required
to speed the reaction up.
AquaCure: Designed for the South African military, these tablets contain chlorine and alum.
The alum causes the suspended solids to flocculate and the chlorine adds 8 PPM chlorine. This is
a great way to treat turbid water, though it will leave a lot of chlorine in clear water (The one
tablet/liter could be halved for clear water.)
The US distributor for Aqua Cure is:
Safesport Manufacturing, Box 11811, Denver, CO 80211 1 800 433 6506
Bleaching Powder (Chlorinated Lime): Can also be purchased and used as a purification means
if nothing else is available. Bleaching powder is 33-37% chlorine when produced, but losses its
chlorine rapidly, particularly when exposed to air, light or moisture.
Calcium Hypochlorite: Also known as High Test Hypochlorite (HTH). Supplied in crystal
form, it is nearly 70% available chlorine. One product, the Sanitizer (formally the Sierra Water
Purifier) uses these crystals to superchlorinate the water to insure pathogens were killed off, then
hydrogen peroxide is added to drive off the residual chlorine. This is the most effective method
of field chlorine treatment. The US military and most aid agencies also use HTH to treat their
water, though a test kit, rather than superchlorination, is used to insure enough chlorine is added.
This is preferable for largescale systems as the residual chlorine will prevent recontamination.
Usually bulk water treatment plants first dilute to HTH to make a 1% working solution at the rate
of 14g HTH per liter of water. While testing to determine exact chlorine needs are preferable, the
solution can be used at the dose rate of 8 drops/gallon, or for larger quantities, 1 part of 1%
solution to 10,000 parts clear water. Either of these doses will result in 1 PPM
From my Preparedness Manual downloadable at:
http://www.mediafire.com/?zghuhkgoqz4
I decided I didn't like drinking swimming pool water...and like you say, the water had to be tested and the chlorine was dissipated quickly.
But in emergency situations, chlorine would not be bad to add for safety...T Y for the info...