Mark Shapley.

Geologic, geomorphic and chemical characteristics of wetlands selected for use in biocriteria development by the Montana Department of Environmental Quality (Volume Appendix B) online

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C MONTANA STATE LIBRARY

551-41 , III \

Nllggc 3 0864 0015 6118 5

1995
Appendix B



Geologic, Geomorphic and Chemical Characteristics

of Wetlands Selected for Use in Biocriteria

Development by the Montana Department of

Environmental Quality



by

Mark D. Shapley

Montana Natural Heritage Program

151 5 East 6th Avenue

Helena, MT 59620

for the

Montana Department of Environmental Quality
Water Quality Division

December, 1995



STATE DOCUMENTS COLLECTION

' ;ay 1 D 2001

MONTANA STATE LIBRARY
,, 1515 E. 6th AVE.
HELENA, MONTANA 59S20



Pro)«ct funding from the U S EnvironmertBl Pro«»ctlor Afleocy tfirough tfie
State WeOand* Protection Projram Swrtxw 104(b)(3) o« ttw Clean W«ef Act



MONTANA STATE LIBRARY

:riiMB:i;ii!ti" ■ ■



3 0864 0015 61



18 5



Geologic, Geomorphic and Chemical Characteristics

of Wetlands Selected for Use in Biocriteria

Developnnent by the Montana Department of

Environmental Quality



by

Mark D. Shapley

Montana Natural Heritage Program

1 51 5 East 6th Avenue

Helena, MT 59620

for the

Montana Department of Environmental Quality
Water Quality Division

December, 1995



STATE DOCUMENTS COLLECTION

';ay 1 O200I

MONTANA STATE LIBRARY
ij^, 1515 E. 6th AVE.
HELENA, MONTANA 59520



Projact funding from ttw U S Environmental Prot»ctK)n Agency thnxiflh tJie
State Weflands Protection Program Section 104(b)(3) o« the Clean Wjtei Act



m 6 2003



Appendix B.



Narrative Summaries of the Physical Setting and Chemical
Characteristics of the DEQ Wetland Characterization Sites



Alkali Lake

Climatic setting. The net annual precipitation balance for Alkali
Lake (from the MAPS database) is approximately -13 inches. This
places the site toward the less evaporative end of the climatic
spectrum for closed basin sites, but near the more evaporative
extreme for Rocky Mountain sample sites. Monthly average
precipitation for the Fortine climatic station shows relatively
even distribution throughout the year, with a moderate peak in May
and June. Annual records from the Fortine station show the 3-year
running average precipitation has been below the long-term mean
during most of the last 30 years. Annual precipitation during the
sample year of 1993 exceeded the average for the period of record
by approximately 5 inches.

Geologic setting. The Alkali Lake basin is underlain by calcareous
till and possibly other glacial sediment types of late(?) Wisconsin
age. Shorelines are composed of coarse-grained sediments in high
energy areas, marly mud in deeper water and sheltered littoral
areas. Bedrock geologic units are of the Proterozoic Belt Series,
probably including the calcareous and dolomitic Helena Formation.

Hydrologic type. Alkali Lake is a glacial depression lacking
surface drainage at current water levels. Strandlines represented
by tree kills indicate historic water levels within the past few
decades which would have allowed surface discharge. Groundwater
outflow is inferred from moderate salinity of this topographically
closed basin.

Basin characteristics. Alkali Lake has a small surface catchment
with respect to lake area and volume. The basin is linear and
shallow at both ends, with a maximum measured depth in mid-basin
of 37 feet. The cluster of lakes in the vicinity display disjunct
water quality; Thirsty Lake, nearby and at a lower elevation,
exceeds Alkali Lake in specific conductance by more than an order
of magnitude. Road construction has partially isolated the eastern
arm of the lake during high-water conditions.

Water chemistry- Alkali Lake is proportionately high in magnesium
and is almost completely depleted in calcium; low calcium
concentrations appear to be maintained by solubility controls,
evidenced by deposition of authigenic carbonate minerals. High
relative magnesium concentrations are typical of hydrologically
similar sample sites. Equilibrium calculations indicate
supersaturation with calcium and magnesium carbonate species.

In comparison to hydrologically similar sample sites, Alkali
Lake exhibits relatively low water-column concentrations of trace
elements. Total organic carbon concentrations are at the high end
for the region and for hydrologically similar sites.

Chemical history. Specific conductance measurements from 1968 were



approximately 25% lower than 1993 and 1994 measurements. Seasonal
measurements in 1993 and 1994 show approximately 10% difference in
salinity. Vegetation indicators show considerably higher lake
volume within the past few decades, implying significantly more
dilute water chemistry. The measured salinity range within the
lake basin was minor, amounting to approximately 5% in specific
conductance .

Sediments. Sediment trace element concentrations are generally low
with respect to regionally and hydrologically similar sample sites.
Trace elements found above detection limits (arsenic, boron, copper
and zinc) occurred at concentrations below the regional mean soil
concentrations for these parameters (Shacklette and Boerngen,
1984) .



Beindy Reservoir

Climatic setting. The net annual precipitation balance for the
Bandy Reservoir site (from the MAPS database) is -15 inches,
placing the site toward the more humid end of the range for
hydrologically and regionally similar sites. Monthly average
precipitation for the Ovando 9 SSE climatic station shows a bimodal
distribution, with a primary June peak and a secondary January
peak. The 3-year moving average of total annual precipitation
remained below (often considerably below) the long-term average
from the mid-1970s through 1993. The total precipitation for 1993
(the year prior to sampling) was very near the long-term average.

Geologic setting. Bandy Reservoir is underlain by calcareous late
Pleistocene till deposited by ice advancing down Monture Creek from
sources in the Swan Range. Bandy Reservoir lies along the kettle-
pocked lateral moraine marking the westward extent of the Monture
advance. The till is described as variable in texture and may
overlie glacial deposits (including outwash) deposited by the
slightly earlier Clearwater glacial advance. Fine-grained Tertiary
aged valley fill deposits underlie glacial deposits at unknown (but
probably shallow) depths.

Bedrock geologic units in the source area for sediments deposited
by the Monture advance include several distinct formations of the
Proterozoic-aged Belt series; large areas are underlain by the
calcareous and dolomitic Helena Formation.

Hydrologic type. Bandy Reservoir is an artificial impoundment of
a natural basin that probably had a prior history as a smaller
natural water body. Presently it provides off -stream storage of
water diverted from Shanley Creek. Discharge is back to Shanley
Creek (and to local irrigated areas?). Water levels are
manipulated for irrigation storage purposes, and probably do not
reflect natural water level fluctuations of unmanipulated nearby
lakes.

Basin characteristics. The natural (closed) catchment of Bandy
Reservoir is small and probably supported only a minor (perhaps
seasonal) pond or wetland similar to many others along the Monture
moraine. As a reservoir, it receives inflow from a large catchment
and has a relatively high catchment to wetland area ratio.
Diversion rates and lake volume are unknown, but the flux of water
through the reservoir is probably relatively rapid.

Water chemistry. At the time of sampling, Bandy Reservoir
contained dilute ("fresh") but highly alkaline calcium-
magnesium/carbonate water. Equilibrium calculations indicate
oversaturation with carbonate species at the sampled pH.
Phosphorous, nitrogen and total organic carbon concentrations were
near the low end of the ranges for hydrologically and regionally
similar sites. Most trace element concentrations were below
detection limits. Arsenic and copper were found at concentrations



near the low end of ranges for similar sites.

Cheaiical history. No chemical data other than those from the DHES
sampling are known for Bandy Reservoir. It is reasonable to infer
that flushing with dilute, high-quality water from Shanley Creek
maintains dissolved constituents within a relatively narrow range.
Prior to hydrologic manipulation, the basin may have developed
somewhat more saline water similar to nearby closed ponds and
wetlands.

Sediments. Arsenic, boron, copper and zinc were found at low to
mid-range concentrations in comparison to hydrologically similar
sites. Selenium and mercury were reported at their respective
detection limits; values for both elements approximate mean
concentrations in soil and other surficial material of the western
U.S. .



Beaver Creek Wetland



Climatic setting. The net annual precipitation balance for the
Beaver Creek site (from the MAPS database) is -6 inches, placing
the site near mid-range in evaporative intensity for Rocky Mountain
sample sites. [At absolute values in this range, the "annual
precipitation balance" should definitely be considered only a
relative scaler of evaporative intensity, not an indicator of the
true sign of the site's moisture balance.] Mean monthly
precipitation for the Seeley Lake Ranger Station climatic station
shows a bimodal distribution with the primary peak in January and
a secondary June maximum. The 3-year running average at Seeley
Lake shows an apparent periodicity in annual precipitation, with
a period of five to six years. Since the early 1970 's, the three-
year average has been mainly below the average for the period of
record. Total precipitation in 1993 (the year prior to sampling)
was about 3 inches below average.

Geologic setting. The Beaver Creek site is underlain by till (and
other glacial sediments?) deposited by the late Pleistocene advance
of glacial ice down Placid Creek. The texture of the till in the
general area is described as sandy; soil drainage, however, is
described as poor. Bedrock formations underlying the area inferred
to have contributed glacial sediments to the site include mainly
noncalcareous formations of the late Proterozoic Belt series.

Hydrologic type. The Beaver Creek wetland is an apparent kettle
lacking discrete surface water inflow or outflow. Mineral
equilibria (see below) may reflect either a ground-water recharge
position for this site, or a lack of carbonate lithologies in local
geologic materials.

Basin characteristics. The WET03 site is one of a cluster of
poorly integrated depressions forming a stepwise profile across an
interfluvial plateau. Ground-water flow between depressions is
inferred from the lack of surface drainage and dilute water quality
of the sample site. The calculated ratio of catchment to wetland
area is toward the higher end for sites included in this type; the
surface catchment used, however, does not discriminate small
internally drained areas and so may not be meaningful to the
hydrology of the wetland site. Road construction may have altered
drainage from this wetland.

Water chemistry. The Beaver Creek wetland displays very dilute
calcium bicarbonate chemistry. The measured total dissolved solids
concentration was among the lowest in the sample set. Mineral
equilibria indicate substantial undersaturation with carbonate
species. Phosphorous concentrations were near the low end of the
range for all sample sites, nitrate was below detection limits, and
the ammonium concentration was mid-range for hydrologically similar
sites. The total organic carbon concentration was among the upper
50% of hydrologically similar sample sites.



Most trace elements were below detection limits; the copper
concentration was mid-range among hydrologically similar sample
sites.

Chemical history. No chemical data other than that provided by the
DHES sampling are known for this site.

Sediments. Extractable concentrations of most trace elements are
below detection limits or well within the range for hydrologically
similar sites. Selenium and nickel were found near the high end
of their ranges for similar sites. Mercury was reported at the
detection limit. Copper, nickel, boron and mercury concentrations
approximated mean values for soils and other surficial materials
in the western U.S. Selenium exceeded the western U.S. mean by a
factor of about 2 .



Bent Flat Fen Proposed RNA

Climatic setting. The net annual precipitation balance for the
Bent Flat fen (from the MAPS database) is -4 inches, placing this
wetland toward the middle of the range shown by Rocky Mountain
sites. Mean monthly precipitation values for the Hungry Horse Dam
climatic station shows a bimodal distribution with June and January
peaks. The recent record for this climatic station is fragmentary;
annual totals for 1991 and 1992 were below average for the period
of record.

Geologic setting. Bent Flat is a calcareous fen underlain by 2
meters of less of peat and organic-rich marl. The fen sediments
are deposited over a surface of dense, clay-rich till. Active
precipitation of carbonate minerals occurs in a complex of pools,
channels and vegetation mats forming string-and-f lark patterning
approximately along the topographic contour of the fen surface.
The fen is supported by ground-water discharge from upland springs
within a few hundred meters upgradient. Adjacent upland slopes are
underlain by tufa and travertine deposited by these springs.

The springs are believed to represent ground-water discharge from
Cambrian limestones underlying slopes and peaks to the east and
northeast.

Hydrologic type. Bent Flat is a patterned fen (unusual in Montana)
with inflow provided by short streams fed by nearby ground-water
discharge. Outflow occurs by a peripheral stream and by
channelized outflow from the toe of the wetland.

Basin characteristics. Ground-water supporting the Bent Flat fen
is recharged over an unknown area. Flow within the fen is complex,
following convoluted surface pathways through interconnected pools
(f larks) and moving as shallow groundwater flow through the
vegetation mat. The fen is developed on a low-gradient slope at the
base of a steep glaciated ridge. Where examined, the hydraulic
conductivity of the underlying glacial materials appears to be low.

Water chemistry. Bent Flat Fen contains relatively dilute, mildly
alkaline calcium-bicarbonate water which actively precipitates
calcite as it moves from the ground-water environment to the fen.
Saturation with calcium carbonate phases is shown by the ubiquitous
deposition of authigenic calcite (and/or aragonite?) around the
outlet springs and within the fen. Deposition may be seasonal, as
equilibrium calculations indicate slight calcite undersaturation
under cold (3 degrees C) temperatures.

Nitrogen (nitrate plus ammonium) concentrations rank in the upper
third among hydrologically similar sites; phosphorous
concentrations are near the lower end of the range. The total
organic carbon concentration at the time of sampling was toward the
upper end of the range shown by hydrologically similar sample
sites.



Chemical history. Prior to the DHES sampling, two water quality
samples were collected from Bent Flat in November of 1993. One
sample came from the immediate area of the springs supplying the
fen. The other was collected from near the lower end of the fen,
bracketing the WET04 site. Generally, major ion chemistry varied
little between the three samples; the springs probably provide
quite stable inlet water chemistry. Minor differences should be
expected due to dilution and concentration effects and possibly
because of changing rates of carbonate precipitation.

Nutrients, however, are more directly tied to biological activity
within the fen and appear to show important spatial and seasonal
variability. In November of 1993, nitrate and ammonium
concentrations both decreased substantially (and disproportionately
to minor dilution effects) between the inlet and lower fen sites,
while total phosphorous and total organic carbon concentrations
increased by factors of four and five respectively. In September
1994, the WET04 site showed total phosphorous and TOC
concentrations respectively seven and ten times higher than the
lower fen site of November 1993.

Sediments. An exceptionally high concentration of extractable
calcium (24%) reflects the marly nature of Bent Flat sediments.
Arsenic, boron, mercury, selenium and zinc occurred in detectable
concentrations in the sample of Bent Flat sediment. All were found
at low concentrations in comparison to the rest of the data set,
with the exception of mercury and selenium. The reported mercury
concentration was slightly above the western U.S. mean for soils
and other surficial materials, and the selenium concentration
exceeded the western U.S. mean by a factor of about 2.



Benton Lake National Wildlife Refuge

Climatic setting. The net annual precipitation balance for Benton
Lake (from the MAPS database) is -27 inches, placing the site
toward the more evaporative end of the range for it's class.
Average monthly precipitation for the Great Falls Airport climatic
station shows a strong May-June peak. Between 1980 and 1993, the
three-year running average of annual precipitation remained near
the mean for the period of record, despite several extreme years.
In 1993 (the year of sampling), annual precipitation exceeded the
average by more than 7 inches. The 1992 total was about 2.5 inches
below average.

Geologic setting. Benton Lake is underlain by a thick sequence of
glaciolacustrine sediments deposited in Glacial Lake Great Falls
during late Pleistocene time. Glacial Lake Great Falls sediments
in the Benton Lake basin are described as composed dominantly of
plastic clay. Till and other surficial materials underlie other
portions of the catchment. Underlying pre-Quaternary formations
include the Marias River Shale and the Blackleaf Formation.

Hydrologic type. Benton Lake is a highly managed system relying on
pumped importation of water from Muddy Creek. There is no surface
water outflow and due to topographic position and geologic
characteristics, no likelihood of significant ground-water outflow.
A large fraction of the Muddy Creek water delivered to Benton Lake
consists of irrigation return flows from the Greenfields Division
of the Sun River Irrigation Project.

Basin cheiracteristics . The catchment to wetland area ratio for
Benton Lake is toward the low end of the range for the sample set.
However, Benton Lake inflows are managed by manipulation of imports
from Muddy Creek. Benton Lake itself is subdivided by dikes into
six separate pools with sequentially lower interconnecting
spillways from the inlet pool to the southeastern end of the lake.
Salinity and disease management involves flooding only some of the
pools during any given year, while others stand dry.

Water chemistry. At the time of sampling in August 1993, Benton
Lake Pool #1 contained alkaline, "oligosaline" water of mixed
cation/sulfate chemistry. Mineral equilibria indicate
oversaturation with carbonate phases and moderate undersaturation
with respect to gypsum. The nitrate concentration was very high,
while phosphorous (total and orthophosphate) and total organic
carbon concentrations were toward the low end of the range for the
wetland type and region. The water column selenium concentration
was the highest of the five sample sites for which detectable
selenium was reported. WET05 was also among the five sites with
detectable nickel reported from the water column. The reported
arsenic concentration was among the lowest for the sample sites.

Chemical history. Monitoring programs of the U.S. Fish and
Wildlife Service and the USGS have generated an intensive (if



brief) water quality data set for Benton Lake. Since 1990,
specific conductance in pond #1 has varied across more than an
order of magnitude, with a maximiam reported concentration of 10920
microsiemens/cm. Three reported selenium concentrations ranged from
.001 to .011 mg/1. Spatial variability within the Benton Lake
complex can also be substantial. Synoptic sampling in August of
1986 showed pool #5 (the southeastern quadrant of the lake) to have
specific conductance approximately four times higher than pool #1;
reported boron concentrations were higher in pool #5 by a factor
of about 3, and arsenic was reported from pool #5 at 63 times the
concentration reported for pool #1.

Sediments. The WET05 site exhibited the highest sampled
concentration of nickel and the highest zinc and second highest
selenium concentrations for a site in it's classification. WET05
was one of only five sites with a reported (barely) detectable
concentration of extractable cobalt. Sediment trace element
concentrations appear to show less spatial variability within the
Benton Lake complex than do water column concentrations. The
reported nickel concentration exceeds mean values for soils and
other surficial materials of the western U.S. by a factor of 4.
Selenium, zinc and cobalt exceed the regional soil means by factors
of 1.5 to 2.



Big Lake

Climatic setting. The MAPS database value for the net annual
precipitation balance at Big Lake is -28 inches, placing the site
among the most strongly evaporative of the sample wetlands. Mean
monthly values for the Rapelje climatic station show a strong May-
June peak in precipitation. The 3-year running average of total
annual precipitation appears to show periodicity, with 6 to 9 years
between peaks. Between 1975 and 1992, the 3-year average remained
at or above the long-term mean during most year. Data for 1993 and
1994 were not retrieved for this station.

Geologic setting. According to published geologic mapping, the Big
Lake basin is underlain by the Bearpaw Shale and lies along the
eastern limb of the Lake Basin Anticline, a structural trap for
hydrocarbons which supports oil and gas production in the area.
Outcrops in the immediate vicinity of WET06 are a well-cemented,
medium grained sandstone believed to be the Virgelle Sandstone.
Surficial sediments at the sampling site are composed of moderately
well-sorted sand, with finer grained material accumulated in
surface depressions created during the alteration excavation and
alteration of the site.

Hydrologic type. Big Lake proper is a structurally controlled
depression lacking surface outflow, which receives runoff from the
entire Cedar Creek basin. The WET06 site is a reconstructed basin
at the inlet to Cedar Creek, intended to retain water from Cedar
Creek during low-water periods. The WET06 site drains to the
greater Big Lake basin, which has slightly lower elevation than the
reconstructed wetland. Water also probably exits the sample site
by infiltration into the sandy, recently disturbed substrate.

Basin characteristics. The large ephemerally flooded Big Lake
basin has a low ratio of catchment to wetland area. The small
wildlife enhancement site sampled at WET06, however, has a very
high catchment to wetland ratio. The enhancement site is controlled
by overflow to Big Lake proper at a maximum water depth of
approximately 3 feet, or about 1.5 feet deeper than during the
conditions observed in October 1994. Turnover of water in the
sample site would be relatively rapid during Cedar Creek runoff
events. Excavated depths vary within the enhancement site.

Water chemistry. At the time of sampling, the WET06 site contained
"hypersaline" sodium sulfate water with relatively low bicarbonate
and carbonate concentrations. Mineral equilibria indicate
substantial oversaturation with carbonate species and near-
equilibrium with gypsum (corroborated by the formation of
authigenic gypsum(?) in samples collected in October 1994).

Phosphorous concentrations were moderate in comparison to
hydrologically similar sites, while the ammonium and total organic
carbon concentrations were toward the high end of the range for
sites of this type.



Along with nearby Hailstone and Half breed Wildlife Refuges, Big
Lake was one of a small handful of sample sites with detectable
nickel found in the water column. Boron and zinc concentrations
were relatively high in comparison to hydrologically similar sample
sites. The arsenic concentration was below detection, unusual
among the sampled sites.

Chemical history. No water quality analyses prior to the DHES
sampling are known. During October of 1994 (six months after
sample collection) field chemical parameters (pH and specific
conductance) were spatially variable within the small constructed
wetland area. Specific conductance measurements ranged from less
than half that reported at the time of sampling, to 10% higher;
the configuration of the constructed site may discourage rapid


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Online LibraryMark ShapleyGeologic, geomorphic and chemical characteristics of wetlands selected for use in biocriteria development by the Montana Department of Environmental Quality (Volume Appendix B) → online text (page 1 of 14)