129 
Water Pollution 
It is contended that no water from the area enters the city 
water system and hence there is no danger of pollution. It was 
admitted, however, that the trail which this rule will close up did 
cross an area draining into Nuuanu Reservoir No. 4, but that 
the danger of disease microbes being introduced into the city 
water system from this source is infinitesimal, if not impossible, 
because water purifies itself in flowing approximately 1,000 feet 
in a formation such as exists there. 
The Sanitary Engineer of the Territorial Board of Health 
informs me that this last statement is misleading and is based on 
a theory that has long been discarded by physicians and sanitary 
engineers. A single discharge of the bowels of a typhoid carrier 
may contain one billion typhoid bacilli, perhaps more at times, 
and 1 per cent of this is large enough to do immense damage. 
One person can discharge in one evacuation of urine enough 
typhoid germs to place one or more of these germs in every 
glassful of a 5,000,000,000 gallon reservoir. When nature calls, 
and her message is of a certain character, we all obey that call 
without unnecessary delay. In the self-purification of streams 
it is not a question of the distance that the water flows, but 
rather of the time it takes for the water to flow from one place 
to another. The majority of sanitary engineers today hold 
that water once contaminated is always dangerous until puri- 
fied, and that polluted water derived from a quick-spilling 
Avatershed, such as this, must always be relatively impure 
and dangerous. 
A sample of earth taken a few years ago from the trail be- 
tween Nuuanu road and Hillebrand Glen was found upon analy- 
sis to contain Bacillus coli, showing how readily the casual tres- 
passer carries germs on his boots from the polluted surface of 
the road into the watershed forest reserve. 
■ It will be seen from the above that there is today great danger 
in the contamination of the city water supply if the area em- 
braced by Rule V is to remain open to trampers, by the pollution 
of water running into Nuuanu Valley from the region of the 
Manoa-Nuuanu Ridge. As I have previously shown, there is 
danger also of pollution of the surface supply which is used for 
domestic purposes by the residents in upper Manoa Valley who 
are above the city mains. The headwaters of these surface 
streams are crossed by the trail which runs across Rule V area 
from Mt. Olympus to Pauoa Flats, and are exposed to direct 
contamination by trampers. 
This rule, however, does not contemplate only present needs, 
but looks to the future, when there will be a much greater de- 
mand for water. The surface water in the Palolo Stream was 
used in the city mains up to a year and a half ago, and the man- 
ager of the city water works informs me that it is needed; and 
