Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-10-01
TAKEN AT 6-MILE ISLAND.
Col. T. P. Roberts Warmly Urges a
Carefully Considered Scheme.
BACTERIA SHUT OUT ENTIRELY
By an Arrangement of Screens, Broken
Stone and sand as Filters
ITS CHEAPNEsS AND FEASIBILITY

full study Of the question of Pittsburg's and
Allegheny's water supply is Colonel I. p.
Roberts, and as usual with this eminent
engineer and public-spirited citizen, the
plan he suggests by which pure and suffi-
cient supply of water may be assured both
cities is strictly practical Colonel Roberts
has revealed already, in a general way, his
views at a meeting of the Chamber of Com
merce and on other occasions recently, when
the subject has been discussed.
He is not one of those who despair
utterly of getting good water from
the Allegheny river, but is rather
an optimist about that streams qualities.
He thinks that Allegheny at least can get
as good water as she needs at once by
merely going up the river as far as Six Mile
Island. Pittsburg, he contends, can do the
same. This is no recent invention OF
Colonel Roberts, for in studying the ever
increasing need for a better water supply,
some years ago he evolved the scheme
which is outlined below. Yesterday,
Colonel Roberts explained this scheme to a
DISPATCH reporter, and illustrated it with
plans involving considerable minute
detail.
An Extensive Plan.
At the northern end of Six-Mile Island
there is wing dam, or United States dyke,
which turns the current away from the
island, and defects it toward the opposite
shore where Negley's Run enters. Colonel
Roberts proposes to make the influent pipes
project from the bead of the island about
600 feet into mid-stream, where the crib
would be located. The water passes through
he infuonf 10 ,r1,ot ie 1aI g.
bay, a sort of reservoir running parallel
with the river and divided from it by rip
rap not necessarily water tight. From this
pool the water would fow through filter
ing screens, arranged upon a plan
which experience in other places
shas proven efficacious. The water
passes first through a wire netting and then
through a succession of tiltering chambers
filed with broken stone and sand, begin
ming with granite in chips as big as your
hand in the first chamber, then sand of a to
a grain coarseness then finer sand, say 1-12
grain, and finally 1-16 grain sand in tine last
chamber Colonel Roberts believes this
filter to be the best adapted to the purpose.
The broken stone and sand are bound to
catch all the mud the water carries with it.
Ii the mud be removed from the water it is
tolerably certain that all the bacteria and
noXious natter of nitrogenOus character
will be deposited in the filter also. Bacteria
stay with their food. The mud is their
larder. The water freed from most if
not all of its injurious impurities by the fl
tiers will flow thence into conduit. 1t will
be practically pure water then: the mud
with its many inhabitants will remain in
the filters, coating the stone chips and
grains of sand. The filters may be cleaned
whenever necessary with reverse stream.
Wells Below the River Bed.
1t is Colonel Roberts idea to break the
conduit in its first stage with two or more
storage wells to be drilled in Six Mile
Island. These wells being dug to a depth
far below the river bed Will add to the
supply of filtered water, for it has been
proven time and again that we'll sunk
close to the river bank will fill up from the
river, and vet supply clear pure water
when the stream from which it draws
its water is at its muddiest. This
has been shown in the we'll put down by the
Monongahela Company on the Southside,
and several other wells drilled under simi-
lar circumstances in this vicinity.
The water having been carried to the
mainland from the island In a conduit is
then to be pumped up by small and mex
pensive engine to a reservoir 40 feet above
low water in the river In case Allegheny
City is alone to be supplied, Colonel Rob-
erts thinks a reservoir covering an acre
would be sufficient. From the reservoir
of course the water could easily be taken
in suitable mains to the city water works.
In the reservoir the water would have an
other chance to deposit any deleterious
substance remaining and would have the
benefit of the action of sun and air
before it passed on to the city. The filter
ing gallery, the storage wells and the whole
service, in short, could be easily enlarged so
as 10 supply Pittsburg as well as Allegheny,
and Colonel Roberts firmly believes that
everyone who investigates the subject full
and carefully will come to the conclusion
that here Is the best method to get pure
water Tor both cities
Intercepting Sewers to Be Built. .
One of the objections likely to be urged
at once to the scheme is that the workhouse
sewers empty into the Allegheny short
distance above the point where it is pro-
posed to locate the crib of the inf1uent
pipes. Colonel Roberts waves this obiec-
tion aside, and all others like it.
Build an intercepting sewer to beyond
the workhouse, and carry tine sewage
below Six-Mile Island as far as NAV be
deemed necessary. In the same way inter-
cepting sewers might be laid on the other
sue Vi lIe AlleSueuy IL the increase OF
population renders it necessary, so as to
give the river the best chance to purify
itself for few miles above the infuent
pipes
Colonel Roberts is not afraid of ALLIE
gheny water. He thinks it bas been ma
Hgned. The sewage of such small towns as
dot its banks at wide intervals does not
contaminate the water of the Allegheny
till the gates of Allegheny City are reached.
Barring oil the water is free from harmful
matter at Si1-Mile ISLAND, and every year sees
the oil refneries decaying and less oil get
ting into the river. No advantage is ap-
parent to Colonel Roberts in going up the
Allegheny river any further than the point
named, as far as getting pure water is con-
eerned Separate the water from the mud
at Six Mile Island and you have as good
drinking water as anyone needs. The saw
ing in money by refraining from long
flights will be immense There is no COM
parison to be made between Colonel Rob
erts' scheme and the other plans, such as
that in which it is proposed to lay mains to
Indian creek, for the cost of the former
would be thousands where the others would
involve millions