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Phosphorous levels
Richard Roseburg, an associate professor at the Oregon
State University Research and
Extension
Center
in
Klamath
Falls
,
said he isn't surprised that new findings show
phosphorous is naturally occurring in
Upper
Klamath Lake
.
Roseburg
said phosphorous is a major element that contributes
to algae blooms in the lake and the
Klamath
River
.
When the blooms die, the decomposition process uses
oxygen in water, which can result in fish die-offs.
He said studies have shown lake sediments are high in
phosphorous and that other quantities come from
springs in and outside the lake.
While phosphorus is used in some fertilizers for such
row crops as potatoes, wheat and onions, he said
"not very much of that tends to move out of the
soil." Phosphorus is also found in cattle manure,
but
Roseburg
said the amounts are generally not significant unless
high quantities are deposited in moving streams.
Maps available
Copies of two geologic maps of
Klamath
Falls
and the
Upper
Klamath
Basin
are available from the Oregon Department of Geology
and Mineral Industries.
Geologic map GMS-118 was started primarily in response
to the 1993 earthquakes that caused widespread damage
to the Klamath County Courthouse, 16 other downtown
Klamath
Falls
buildings and the neighboring region.
Open-File Report O-07-05 is a mapping project that
began in support of GMS-118 and was expanded because
of the basin's increased focus on water issues.
"This compilation of 47 different geologic maps
provides critical information for understanding the
groundwater resources and the connections between
groundwater and surface water in the upper
Klamath
Basin
,"
said Ian Madin, the department's chief scientist.
"It also identifies hundreds of newly mapped
volcanoes in the area that have erupted over the past
few million years into an environment of giant
lakes."
The two maps are available on CD-ROM for $10 each.
Printed copies are $15 each. They are available from
the Nature of the
Northwest
Information
Center
,
800
NE Oregon St., Suite 177
,
Portland
,
OR
97232
;
by calling (503) 872-2750; or online at www.naturenw.org.
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Maps
put basin's water, fertilizer in perspective
Geologic
study changes thought on sources of irrigation, water quality
Lee
Juillerat
For the Capital Press
March 28, 2008
KLAMATH FALLS
,
Ore.
- Recent geological
studies in
Southern Oregon
's
Klamath
Basin
may change some
long-held assumptions about where to drill for water wells and the
impacts of fertilizer and manure on
Upper Klamath Lake
's water quality.
The Oregon Department of Geology and Mineral Industries recently
released two geologic maps of
Klamath Falls
and
Klamath
County
's
Upper
Klamath
Basin
.
Information-gathering for the maps began in 1998.
"It's very interesting to have an understanding of the
geologic history, and it's different than what we thought,"
said Ian Nadin, the department's chief scientist.
Among key points:
n Most of the volcanic activity that has shaped the
Upper
Klamath
Basin
has occurred within
the past 1 million to 2 million years. "If we go back 3
million years, (the terrain) was pretty much as flat as a
pancake," Nadin said.
n The upper basin has 464 volcanoes, which range from massive
mountains like Shasta and McLoughlin to small cinder cones.
n By identifying fault lines, which typically are sources of
underground water, the probability of locating and drilling less
expensive, high-volume water producing wells is improved.
n Many ridges and mountains previously thought to be lava flows
that contain underground aquifers are actually thin layers of lava
atop chalk rock and are not good prospects for drilling successful
wells.
n Higher-than-normal naturally occurring levels of phosphorus are
responsible for reducing water quality in Upper Klamath and other
lakes. Ranchers and farmers who use fertilizers, as well as cattle
manure, have historically been blamed for the unusually high
phosphorus levels.
Nadin said the findings involving phosphorus are important because
steps to reduce fertilizer or cattle grazing use could harm crop
production and ranching while having little or no impact on
improving water quality. Although the amount of naturally
occurring phosphorus is small, 1 percent, he said the amount is 10
times higher than in other areas. Phosphorous is found in rocks,
sediment and water from springs.
"Some of that impact of phosphorous is natural. If a large
percentage is natural and farmers are not allowed to use
phosphorous fertilizer, it could have no impact on the water
quality but could be detrimental to farmers," Nadin said.
"Changing when and how you till may have more impact than how
and when you fertilize."
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