Verifying product water. The NCOIC of the Water Supply Section must also know how to verify the product
water and determine if it is potable. Once the water has been treated the quality must be checked to determine if it
meets the standards developed by the international agreements among NATO Forces and the Quadpartite Armies.
These organizations have agreed, when operations are on land, to adopt minimum requirements for potability of
drinking water to be issued to troops in combat zones or in any other strictly emergency situation. As a member
of both organizations, the United States has agreed to accept and provide water meeting standards when
participating in mutual logistical water support under these field conditions. The standards are based on the
anticipated duration of consumption and are broken down into three categories.
Emergency situations. No standards apply when personnel are cut off from supply lines and treated water
is not available from QM supplies. Each individual should select the clearest, cleanest water with the least odor
and then treat the water using individual water purification procedures.
Short-term consumption. The standards listed for short-term consumption apply to units operating for
seven consecutive days or less, when the commander, upon medical advice, determines that a field operation
exists which prevents troop access to drinking water meeting long-term consumption standards. Units can
consume this quality of water for only seven consecutive days. The commander imposing the short-term
consumption standards must accept potential troop performance degradation, increase of disease, casualties from
toxic substances, and reduced combat efficiency with each day the imposition remains in effect.
Long-Term consumption. The standards listed for long-term consumption apply to all situations where
treated water is produced by water purification units. These are the standards which must be met and verified by
the water supply NCO.
Chlorine disinfection. Chlorination will be used for disinfection of potable water in all cases with the exception
of individual or small unit water purification for which iodine tablets may be used. The efficiency of chlorine
disinfection is affected by the following variables: the form of the chlorine present, the pH of the water, and the
contact time. As the pH of the water increases from 5 to 9, the form of the chlorine residual changes from
hypochlorous acid (HOC1)(the most effective form) to hypochlorite ion (OCI-) which is less effective. The most
effective disinfection occurs when the pH is between 5.5 and 6.5.
Chlorine residuals. Under normal operating conditions, water purification personnel will add sufficient chlorine
to treated water to produce a chlorine residual of at least 2.0 PPM after 30 minutes contact time at a pH between
6.5 and 7.5. For the ROWPU, chlorine is added after the RO process because chlorine will damage the