HomeMy WebLinkAbout2015 ICR TMDL Status Rpt_final
South Tahoe Public Utility District Indian Creek Reservoir TMDL Progress Report for 2015 Final
2/26/2016
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1 Introduction
In April 2012, the Lahontan Regional Water Quality Control Board (LRWQCB) developed guidance (draft
Indian Creek Reservoir Total Maximum Daily Load (TMDL) Tracking Plan) to be used by the South Tahoe
Public Utility District (District) for the presentation and analysis of water quality data collected from
Indian Creek Reservoir, Alpine County, CA (LRWQCB, 2012). These data are to be reported annually to
evaluate Total Maximum Daily Load (TMDL) implementation progress and adaptively manage
expectations for meeting TMDL targets at Indian Creek Reservoir (ICR). The following has been prepared
to satisfy this annual TMDL reporting requirement for the 2015 calendar year.
2 Background
ICR is a 3,160 acre-foot (AF) capacity fresh water reservoir located approximately 26 miles southeast of
South Lake Tahoe, within Section 4, T. 10 N, R. 20 E in the northeast portion of Alpine County, California
(Figure 1). ICR was constructed in 1967 for the temporary storage of treated wastewater. Since 1989, all
make-up water to ICR is provided by fresh water diversions from Indian Creek and the West Fork of the
Carson River (WFCR). During 2015, the volume of WFCR water diverted to ICR was about 348 AF; which
is about 40% of the average annual volume diverted over the preceding five years (2011 – 2015).
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ICR is Section 303(d) listed for eutrophication. Since the 1970s, it has shown symptoms of
eutrophication including impairment of aquatic life and recreational uses and violation of narrative and
numerical water quality objectives. Phosphorus has been identified as the primary nutrient contributing
to eutrophication. The greatest source of phosphorus loading is believed to be from internal sources
(sediment load).
In July 2002, to evaluate water quality improvement, the LRWQCB established numeric targets for five
(5) indicator parameters: Total Phosphorus (TP); Dissolved Oxygen (DO); Secchi Depth (SD); Chlorophyll
a (Chl-a); and Carlson Trophic State Index (TSI). Interim and long-term numeric targets from the ICR
TMDL are summarized in Table 1.
Indicator Interim Target
(Attained by 2013)
Final Target
(Attained by 2024)
≤≤
7-day mean min. – 5.0 mg/L
1-day min. – 4.0 mg/L
i) DO depressed not more than 10%;
ii)DO % Saturation ≥ 80%; or
iii) DO ≥7.0 mg/L
≥
≤
≤
Table 1. Water quality indicator parameters and numeric targets
3 HOS Operation
In 2004, Kennedy Jenks Consultants (KJC) identified hypolimnetic oxygenation as a preferred alternative
to remove beneficial use impairment by reversing eutrophication in ICR (KJC, 2004). In 2005, Alex Horne
Associates researched the methods of hypolimnetic oxygenation employed in lakes and reservoirs and
recommended a submerged down-flow contact oxygenation system (SDCO or Speece Cone) as the best
device for use at ICR (A. Horne Associates, 2005). In December 2006, the District was awarded a Clean
Water Act Section 319 (h) Nonpoint Source Implementation Grant (Agreement No. 06-244-556-0) for
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the purpose of reducing internal loading of phosphorus to ICR and to optimize reservoir management
for protection and enhancement of aquatic life and recreational uses. In 2007, Brown & Caldwell
consultants developed an engineering pre-design for the ICR Hypolimnetic Oxygenation System (HOS)
(Brown & Caldwell, 2007). In 2008, the District acquired a BLM Right-of-Way Grant to permit the
construction, operation, maintenance and termination of the ICR HOS and completed the engineering
plans and specifications required for construction.
The ICR HOS consists of an:
• In-reservoir oxygen delivery system (Speece Cone);
• On-site oxygen generation system; and
• Underground and submerged utilities connecting the oxygen generator to the Speece Cone.
In June 2008, work for the on-site oxygen generation system started with construction of the equipment
building. In December 2008, the Speece Cone was installed in the deepest portion of ICR (water depth =
approximately 32 feet) and connected to the oxygen generator. The Speece Cone is a 10’ x 5’ diameter,
3/16” mild steel cone fitted with a 2’ x 5’ diameter skirt and bottom plate mounted on a 12’ x 6’ steel
equipment skid. The equipment skid is fitted with a 7.5 hp submersible pump and motor capable of
circulating approximately 2.1 cubic feet per second (cfs) of water through the Speece Cone. The oxygen
generation system connected to the Speece Cone includes a 25 hp rotary-screw compressor and
pressure swing adsorption (PSA) oxygen generator housed in an on-shore equipment building. The
oxygen generator is an Air Sep AS-450 capable of producing up to 880 pounds per day (lbs/day) of
oxygen, as a 95% purity gas. Utility connections between the Speece Cone and oxygen generator system
consists of a 1-inch HDPE oxygen delivery line and Type G power cable housed in an 8-inch HDPE
protective conduit.
The HOS is operated during the late spring and summer to deliver oxygen to ICR for water quality and
aquatic habitat improvement. Run time (in hours), average generation rate (in pounds per day) and
total amount of oxygen produced (in pounds) for each year of operation is provided below in Table 2. In
2015, the HOS delivered a total of 95,319 pounds of oxygen to ICR. The HOS operated for 3,218 hours,
generating oxygen at an average rate of 575 lbs/day.
YEAR OPERATING PERIOD
2009 6/01/2009 10/28/2009 2,345 72,819 489
2010 5/03/2010 10/29/2010 3,216 91,112 509
2011 4/06/2011 10/31/2011 3,856 109,300 525
2012 4/05/2012 10/12/2012 2,926 83,692 442
2013 4/15/2013 10/11/2013 3,590 106,340 551
2014 4/8/2014 10/10/2014 3,493 108,515 587
2015 4/14/2015 10/16/2015 3,218 95,319 515
Table 2. ICR hypolimnetic oxygenation system (HOS) operation periods.
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During operation, District personnel monitor the oxygen generation system on a regular basis (2 to 3
times per week). Operating parameters include run time, air pressures, air dryer temperature; oxygen
pressures; oxygen flow, pump amps and building temperature. In September 2011, the District
inspected the system to evaluate performance and determined that the oxygen generation system run
time is being limited by elevated building temperature and oxygen system output is being limited air
receiver tank volume.
The equipment building housing the oxygen generator includes electrical equipment and an air
compressor that generate large quantities of heat. The equipment building is ventilated using a 6,750
scfm direct-drive wall exhaust fan. The exhaust fan draws ambient air into the building through an air
vent and exhausts the air through a discharge vent to remove heat from the equipment room. During
hot weather, average high time temperatures at ICR can easily exceed 85 degrees Fahrenheit. In order
to prevent overheating of the air dryer, the District has not run the system during daytime hours. In
August 2012, the District installed new ductwork to better exhaust the discharge from the air
compressor and reduce the heat load in the building. Improving the ventilation should improve the
average oxygen generator run time.
The Air Sep AS-450 uses pressure-swing adsorption technology to produce pure oxygen for delivery to
ICR. The oxygen generator consists of two adsorber vessels filled with an inert ceramic material
(molecular sieve) that adsorbs nitrogen from air under pressure, separating the compressed air into
oxygen. As compressed air passes through one of the adsorbers, the molecular sieve adsorbs the
nitrogen. This allows the remaining oxygen to pass through and exit the adsorber as a product gas which
is delivered under pressure to the oxygen receiver tank where it is stored prior to discharge to ICR.
Before the adsorber becomes saturated with nitrogen; the inlet air flow switches to the second
adsorber. The first adsorber is then regenerated by desorbing the nitrogen through depressurization
(vented to atmosphere) and purging it with oxygen. The complete cycle is then repeated. During 2013, a
new 240-gallon air receiver tank was added to triple the existing air receiver volume; a complete service
inspection and repair of the oxygen generator (Air Sep AS-450) and annual service and repair of the Air
Dryer (Kaeser TC 44) were also completed. Addition of the air receiver tank increased air volume,
thereby increasing the flow and air pressure through the Air Sep AS-450 and oxygen output in pounds
per day (lbs/day) to the Speece Cone.
During 2015, the following HOS maintenance was performed:
• Oxygen Generation System - annual service inspection and maintenance:
o Maintain screw compressor (ASD 30): Major service; repaired Tecalan line, replaced oil,
oil filter, filter mat and oil separator cartridge;
o Maintain Air Dryer (TC 44): annual service inspection; replaced inline filter sleeves and
auto drains;
o Maintain compressor air filter (KOR-100): changed air filter cartridge;
o Maintain compressor air filter separator (KFS-100): no service; and
o Maintain compressor oil-water separator (Aquamat 2): no service.
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During the 2015 operating period, the oxygen generator ran at about 80% of its output capacity. The run
time for the oxygenation system averaged about 17.4 hours per day.
Estimated costs for construction, operation and monitoring of the ICR HOS are provided below in Table
3. Total costs for the engineering and construction of the ICR HOS is estimated at $837,300. During
2015, approximately $20,590 was expended by the District for the continued operation and
maintenance of the oxygenation system and ICR water quality monitoring.
YEAR
CO
N
T
R
A
C
T
O
R
$91,880 $39,615 $4,511 $1,850 $137,856
$232,559 $30,355 $60,700 $210,961 $21,003 $45 $1,322 $556,945
$91,733 $24,609 $16,234 $41,616 $266 $10,507 $276 $185,241
$11,431 $15,846 $27,277
$12,237 $17,745 $29,982
$8,490 $14,800 $23,290
$6,158 $7,494 $2,044 $17,058 $494 $33,248
$2,832 $9,236 ($265) $19,377 $559 $31,738
$2,055 $4,823 $13,712 $20,590
Table 3. ICR HOS annual construction, operation and monitoring costs.
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4 Current Data - 2015
The ICR TMDL Tracking Plan (LRWQCB, 2012) requires the reporting of water quality monitoring data
from reservoir stations: ICR-1, ICR-3 and ICR-5 (see Figure 2). ICR-1 is located nearest the Speece Cone,
at the north end and within the deepest portion of the reservoir. ICR-3 is located near the center of the
reservoir and within moderate water depths. ICR-5 is located near the south end of the reservoir within
relatively shallow water depths. Reservoir water quality samples and vertical profiles of field measured
temperature and dissolved oxygen are collected from each station on a monthly basis (weather
permitting). The analytical results for the 2015 raw water samples are provided in Appendix A. The
indicator parameter results are summarized in Table 4. A plot showing the dissolved oxygen monitoring
results is provided as Figure 4.
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INDICATOR UNITS Interim
Target
(2013)
REPORTING
REQUIREMENT
Total
Phosphorus
(TP)
Mean
≤ 0.04
ICR-3,
ICR-5
collected from all depths
from all sites over the
reporting period.
Oxygen
(DO)
Mean
min.
≥ 4.0
ICR-3,
ICR-5
collected from all depths
at each site measured
monthly over the
reporting period.
See Figure 4.
(SD) Mean
≥ 2
ICR-3,
ICR-5
collected over the
reporting period.
(Chl-a) Mean
≤ 10
ICR-3,
ICR-5
collected over the
reporting period.
Index - Secchi
Disk
[TSI(SD)]
Mean
TSI ≤ 45
units
ICR-3,
ICR-5
calculated from SD
readings (in meters)
collected from all sites
over the reporting
period.
Index -
Chlorophyll-a
[TSI(Chl-a)]
Mean
TSI ≤ 45
units
ICR-3,
ICR-5
calculated from Chl-a
concentrations (in µg/l)
collected from all sites
over the reporting
period.
Index - Total
Phosphorus
[TSI (TP)]
Mean
TSI ≤ 45
units
ICR-3,
ICR-5
calculated from TP
concentrations (in µg/l)
collected from all sites
over the reporting
period.
Table 4. ICR TMDL 2015 Summary of Results.
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5 TMDL Targets
The ICR TMDL Tracking Plan requires evaluation of the collected indicator parameter data to ascertain
progress toward achieving ICR numeric targets. The following graphs are provided for evaluation.
5.1 Total Phosphorus (TP)
The District collects water quality samples from each site at ICR, one day each month as weather
permits. The interim target for TP is less than or equal to 0.04 milligrams per liter (mg/L), as the mean
annual concentration in the water column. In order to evaluate TP levels in the reservoir, all available
data for sites ICR-1, ICR-3 and ICR-5 were combined and analyzed as an annual mean (see Figure 3).
Review of Figure 3 shows that TP annual mean remained at or below the target level of 0.04 mg/L from
2010 through 2014.
In 2015, the TP annual mean increased slightly to 0.045 mg/L; above the target level. During the July
sampling event (7/14/2015), exceptionally high levels of TP were reported in the shallow water samples
(0.5 ft depth) collected from two of the three reservoir stations as follows; ICR-1 (0.200 mg/L); and ICR-3
(0.141 mg/L)(see Appendix A). These exceptionally high concentrations are believed to have skewed the
TP annual mean to above the interim target.
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Figure 3. Total phosphorus levels at ICR, plotted as an annual mean, in milligrams per liter (mg/L). During
2015, the TP annual mean increased above the interim target level. This increase is attributed to the
exceptionally high TP concentrations reported in two of the three shallow water samples collected
during the July (7/14/2015) sampling event.
5.2 Dissolved Oxygen (DO)
The District collects DO readings one day each month, as weather permits, from each site at ICR. The
interim target value requires a single day minimum of greater than or equal to 4.0 mg/L, as the mean
concentration in the water column, at each monitoring site. In order to evaluate DO levels in the
reservoir, the data were analyzed by averaging DO readings collected through the water column at each
site (ICR-1, ICR-3 and ICR-5) and plotted as a daily mean for each month of the year (see Figure 4).
Review of Figure 4 shows that daily mean DO levels were greater than 4.0 mg/L at each site for each
monitoring day during 2015.
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
2007 2008 2009 2010 2011 2012 2013 2014 2015
AN
N
U
A
L
M
E
A
N
(
m
g
/
L
)
INDIAN CREEK RESERVOIR
TOTAL PHOSPHORUS
Interim Target (≤ 0.04 mg/L)
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Figure 4. Daily mean dissolved oxygen levels measured at ICR, in milligrams per liter (mg/L).
In order to evaluate ICR TMDL implementation progress, historical daily mean DO levels measured at
ICR-1, ICR-3 and ICR-5 were plotted from 2007 through 2015 (see Figure 5). Review of Figure 5 shows
that daily mean DO concentrations were less than 4.0 mg/L at ICR-1 during August 2007, August 2008
and August 2011. Since 2011, daily mean DO concentrations have steadily increased and remained
greater than 4.0 mg/L at all monitoring sites.
0.00
2.00
4.00
6.00
8.00
10.00
12.00
Di
s
s
o
l
v
e
d
O
x
y
g
e
n
(
i
n
m
g
/
L
)
INDIAN CREEK RESERVOIR
ICR-1 ICR-3 ICR-5
Interim Target (≥ 4.0 mg/L)
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Figure 5. Daily mean dissolved oxygen levels measured at ICR from 2007 through 2015, in milligrams per
liter (mg/L).
5.3 Secchi Depth (SD)
The District collects SD readings one day each month, as weather permits, from each site at ICR. The
interim target value requires a summer mean value of greater than or equal to 2.0 meters water depth
for the entire reservoir. In order to evaluate SD levels at ICR, the data were analyzed by averaging the
SD readings measured during the summer (June, July and August) at ICR-1, ICR-3 and ICR-5 and plotted
as a summer mean for each year (see Figure 6). Review of Figure 6 shows that, since 2009, summer
mean SD levels have increased to greater than 2.0 meters since 2010. During 2015, summer mean SD
(2.66 meters) increased compared to the previous year’s summer mean (2.20 meters).
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
Me
a
n
D
i
s
s
o
l
v
e
d
O
x
y
g
e
n
(
m
g
/
L
)
INDIAN CREEK RESERVOIR
ICR-1 ICR-3 ICR-5
Interim Target (≥ 4.0 mg/L)
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Figure 6. Summer mean secchi depth readings measured at ICR during June, July and August 2007
through 2015, in meters.
5.4 Chlorophyll a (Chl-a)
The District analyzes water quality samples collected one day each month, as weather permits, through
the entire water column for Chl-a at each site. The TMDL target value requires a summer mean value of
less than or equal to 10 milligrams per cubic meter (mg/m3), equivalent to micrograms per liter, for the
entire reservoir. In order to evaluate Chl-a levels at ICR, the data were evaluated by averaging the Chl-a
values measured during the summer (June, July and August) at ICR-1, ICR-3 and ICR-5 and plotted as a
summer mean for each year (see Figure 7). Prior to statistical evaluation, an imputed value of one-half
the method detection level (MDL) was substituted for Chl-a values below the MDL. Review of Figure 7
shows that, since 2008, Chl-a levels have been decreasing and have been less than 10 mg/m3 in 2012
and 2013.In In 2014 the Chl-a summer mean value (10.9 mg/m3) increased to slightly above the TMDL
target level.
In 2015, the Chl-a summer mean value further increased to 34.7 mg/m3. During the July sampling event
(7/14/2015), exceptionally high levels of Chl-a were reported in the shallow water samples (0.5 ft depth)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
2007 2008 2009 2010 2011 2012 2013 2014 2015
SE
C
C
H
I
D
E
P
T
H
(
m
e
t
e
r
s
)
- SU
M
M
E
R
M
E
A
N
INDIAN CREEK RESERVOIR
SECCHI DEPTH
TMDL Target (≥ 2.0 Meters)
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collected at each of the reservoir stations as follows; ICR-1 (200 mg/m3); 1CR-3 (240 mg/m3); and ICR-5
(84 mg/m3). Algae and weeds were visible at ICR-1 during the June, July and August sampling events (see
Appendix A).
Figure 7. Summer mean chlorophyll-a concentrations measured at ICR during June, July and August 2007
through 2015, in milligrams per cubic meter (mg/m3). The high chlorophyll-a summer mean value for
2015 is attributed to the exceptionally high chlorophyll-a concentrations reported in all three of the
shallow water samples collected during the July (7/14/2015) sampling event.
5.5 Trophic State Index
The ICR TMDL Tracking Plan requires that the summer (June, July and August) TP, SD and Chl-a values be
used to calculate a trophic state index (TSI) for each parameter using standard EPA calculations. The
TMDL target value requires a TSI of less than or equal to 45 units for the entire reservoir. In order to
evaluate TSI, a TSI for each parameter value [TSI(TP), TSI(SD) and TSI(Chl-a)] was calculated. The TSI for
all values were then used to produce an average reservoir TSI for each parameter (see Figure 8). Review
0
5
10
15
20
25
30
35
40
2007 2008 2009 2010 2011 2012 2013 2014 2015
CH
L
O
R
O
P
H
Y
L
L
- a
(
m
g
/
m
3
)
- SU
M
M
E
R
M
E
A
N
INDIAN CREEK RESERVOIR
CHLOROPHYLL - a
TMDL Target (≤ 10.0 mg/m3
14
of Figure 8 shows that, since 2009, average reservoir TSI (TP) and TSI (SD) have been decreasing. TSI (SD)
and TSI (Chl-a) were less than 45 units in 2012 and 2013. In 2014 and 2015 TSI(SD), TSI (Chl-a) and TSI
(TP) summer values increased to above TMDL Target levels. Compared to the previous year’s values;
average TSI (SD) slightly decreased (48 units); average TSI (Chl-a) remained unchanged (53 units); and
average TSI (TP) increased (58 units) during 2015.
Figure 8. Carlson trophic state index (TSI) values for sechhi depth, chlorophyll-a, and total phosphorus,
during June, July and August 2007 through 2015, in TSI units.
25
30
35
40
45
50
55
60
65
70
2007 2008 2009 2010 2011 2012 2013 2014 2015
TR
O
P
H
I
C
S
T
A
T
E
I
N
D
E
X
INDIAN CREEK RESERVOIR
TSI (SD)TSI (Chl-a)TSI (TP)
TMDL Target (≤ 45 TSI units)
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6 Summary & Conclusions
Evaluation of the 2015 ICR water quality data shows that:
1. Total Phosphorus (TP): the annual mean of samples collected at ICR-1, ICR-3 and ICR-5 is 0.045
mg/L, slightly above TMDL interim target levels. The increase in the TP annual mean above the
interim target is attributed to exceptionally high TP concentrations reported in two of the three
shallow water samples collected during the July 2015 sampling event; skewing the annual mean
to higher values.
2. Dissolved Oxygen (DO); the daily mean of samples collected at ICR-1, ICR-3 and ICR-5 are greater
than 4.0 mg/L, in compliance with TMDL interim target levels.
3. Secchi Depth (SD): the summer mean for all measurements collected at ICR-1, ICR-3 and ICR-5 is
2.66 meters, in compliance with TMDL numeric targets.
4. Chlorophyll-a (Chl-a): the summer mean for all samples collected at sites ICR-1, ICR-3 and ICR-5
is 34.7 mg/m3, significantly above TMDL numeric targets. The high summer mean is attributed to
the exceptionally high Chl-a concentrations reported in the shallow water samples collected
during the July 2015 sampling event; skewing the summer mean to higher values.
5. Trophic State Index (TSI): Using the TP, SD and Chl-a values collected during June, July and
August, the average reservoir TSI are as follows: TSI (TP) = 58; TSI (SD) = 48; and TSI (Chl-a) = 53.
The TSI (TP), TSI (SD) and TSI (Chl-a) are above TMDL numeric targets.
7 References
Alex Horne Associates, 2005. Water Quality Improvements in Indian Creek, Alpine County California:
Pre-Design for Hypolimnetic Oxygenation, June 25, 2005, revised August 22, 2005.
Brown and Caldwell, 2007. Technical Memorandum No. 1: South Tahoe PUD ICR Oxygenation Pre-Design
Tech Memo, September 11, 2007.
Kennedy Jenks Consultants, 2004. Indian Creek Reservoir TMDL Implementation Plan, December 9, 2004
Lahontan Regional Water Quality Control Board, 2012. Draft Indian Creek Reservoir Total Maximum
Daily Load (TMDL) Tracking Plan, April 27, 2012.
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APPENDIX A
ANALYTICAL RESULTS
2015 ICR WATER QUALITY DATA
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2015
Secchi NH3 +
Depth Total P D.O.D.O. Chlorophyll Depth NH4 NH3-N Org-N TKN NO3-N NO2-N Total N PO4-P
Date Site Ft mg/l mg/l % SAT mg/m3 ft. mg/L mg/l mg/l mg/l mg/l mg/l mg/L mg/l
01/13/15 ICR-01 0.0
02/11/15 ICR-01 0.9 0.039 11.05 88.0 19.0 5.45 0.059 <0.020 0.892 0.951 0.042 <0.010 0.993 <0.010
02/11/15 ICR-01 21.0 0.049 10.85 85.4 18.0 0.052 <0.020 0.988 1.040 0.038 <0.010 1.080 <0.010
02/11/15 ICR-01 36.0 0.040 10.73 84.3 18.0 0.067 <0.020 0.905 0.972 0.038 <0.010 1.010 <0.010
02/11/15 ICR-03 0.9 0.038 11.00 87.6 18.0 5.53 0.063 <0.020 0.901 0.964 0.036 <0.010 1.000 <0.010
02/11/15 ICR-03 21.0 0.053 10.66 83.8 16.0 0.067 <0.020 0.894 0.961 0.037 <0.010 0.998 <0.010
02/11/15 ICR-05 0.9 0.044 10.86 86.4 17.0 5.82 0.063 <0.020 0.957 1.020 0.045 <0.010 1.060 <0.010
03/18/15 ICR-01 0.9 0.035 9.69 84.7 11.0 6.30 0.023 <0.020 0.889 0.912 0.010 <0.010 0.922 <0.010
03/18/15 ICR-01 18.0 0.043 9.42 81.7 8.0 0.031 <0.020 0.944 0.975 0.010 <0.010 0.985 <0.010
03/18/15 ICR-01 36.0 0.044 9.24 79.6 7.0 0.031 <0.020 0.979 1.010 0.010 <0.010 1.020 <0.010
03/18/15 ICR-03 0.9 0.038 9.58 83.5 10.0 6.62 0.024 <0.020 0.884 0.908 <0.010 <0.010 0.908 <0.010
03/18/15 ICR-03 12.0 0.043 9.44 81.6 8.0 0.031 <0.020 0.939 0.970 <0.010 <0.010 0.970 <0.010
03/18/15 ICR-05 0.9 0.037 9.40 81.0 11.0 6.92 0.037 <0.020 0.873 0.910 0.013 <0.010 0.923 <0.010
04/21/15 ICR-01 3.0 0.034 10.54 98.7 7.0 6.05 <0.020 <0.020 0.867 0.887 <0.010 <0.010 0.887 <0.010
04/21/15 ICR-01 17.9 0.043 10.71 99.1 11.0 <0.020 <0.020 0.914 0.934 <0.010 <0.010 0.934 <0.010
04/21/15 ICR-01 36.0 0.040 9.70 88.3 8.0 <0.020 <0.020 0.871 0.891 <0.010 <0.010 0.891 <0.010
04/21/15 ICR-03 2.6 0.035 10.74 100.6 10.0 5.20 <0.020 <0.020 0.903 0.923 <0.010 <0.010 0.923 <0.010
04/21/15 ICR-03 18.0 0.043 10.15 91.5 6.0 <0.020 <0.020 0.980 1.000 <0.010 <0.010 1.000 <0.010
04/21/15 ICR-05 0.9 0.035 10.54 98.7 9.0 5.30 <0.020 <0.020 0.939 0.959 <0.010 <0.010 0.959 <0.010
05/20/15 ICR-01 0.5 0.024 10.60 100.6 <2.0 15.04 <0.020 <0.020 0.744 0.764 <0.010 <0.010 0.764 <0.010
05/20/15 ICR-01 18.1 0.031 10.60 99.8 3.0 <0.020 <0.020 0.777 0.797 <0.010 <0.010 0.797 <0.010
05/20/15 ICR-01 36.2 0.035 9.50 88.8 <2.0 0.020 <0.020 0.820 0.840 <0.010 <0.010 0.840 <0.010
05/20/15 ICR-03 0.5 0.026 10.50 100.1 <2.0 15.10 <0.020 <0.020 0.754 0.774 <0.010 <0.010 0.774 <0.010
05/20/15 ICR-03 21.1 0.046 10.50 97.9 2.0 <0.020 <0.020 0.844 0.864 <0.010 <0.010 0.864 <0.010
05/20/15 ICR-05 0.5 0.036 10.50 99.2 <2.0 <0.020 <0.020 0.795 0.815 <0.010 <0.010 0.815 <0.010
06/17/15 ICR-01 0.9 0.026 8.97 98.6 4.0 17.10 <0.020 <0.020 0.712 0.732 <0.010 <0.010 0.732 <0.010
06/17/15 ICR-01 18.0 0.028 8.97 97.6 4.0 <0.020 <0.020 0.711 0.731 <0.010 <0.010 0.731 <0.010
06/17/15 ICR-01 36.0 0.039 8.37 89.9 3.0 0.024 <0.020 0.739 0.763 <0.010 <0.010 0.763 <0.010
06/17/15 ICR-03 0.9 0.026 8.94 98.3 4.0 15.04 <0.020 <0.020 0.736 0.756 <0.010 <0.010 0.756 <0.010
06/17/15 ICR-03 21.0 0.031 9.04 97.3 3.0 <0.020 <0.020 0.708 0.728 <0.010 <0.010 0.728 <0.010
06/17/15 ICR-05 1.0 0.026 8.98 98.7 3.0 <0.020 <0.020 0.704 0.724 <0.010 <0.010 0.724 <0.010
07/14/15 ICR-01 0.5 0.200 12.14 137.2 200.0 3.20 <0.020 <0.020 4.030 4.050 <0.010 <0.010 4.050 <0.010
07/14/15 ICR-01 18.0 0.030 8.90 96.4 9.0 0.046 0.021 0.716 0.762 <0.010 <0.010 0.762 0.025
07/14/15 ICR-01 36.0 0.045 7.82 84.0 4.0 0.107 0.043 0.712 0.819 <0.010 <0.010 0.819 0.012
07/14/15 ICR-03 0.5 0.141 12.13 136.6 240.0 3.80 <0.020 <0.020 3.230 3.250 <0.010 <0.010 3.250 <0.010
07/14/15 ICR-03 21.0 0.024 8.37 90.3 6.0 0.029 <0.020 0.696 0.725 <0.010 <0.010 0.725 <0.010
07/14/15 ICR-05 0.5 0.056 10.75 120.8 84.0 7.20 <0.020 <0.020 1.250 1.270 <0.010 <0.010 1.270 <0.010
08/12/15 ICR-01 0.9 0.038 9.87 107.3 14.0 8.75 <0.020 <0.020 0.966 0.986 <0.010 <0.010 0.986 <0.010
08/12/15 ICR-01 18.0 0.040 9.18 98.8 7.0 <0.020 <0.020 0.886 0.906 <0.010 <0.010 0.906 <0.010
08/12/15 ICR-01 36.0 0.044 8.69 92.7 4.0 <0.020 <0.020 0.825 0.845 <0.010 <0.010 0.845 <0.010
08/12/15 ICR-03 0.9 0.036 9.61 104.3 11.0 8.25 <0.020 <0.020 0.887 0.907 <0.010 <0.010 0.907 <0.010
08/12/15 ICR-03 21.0 0.034 8.75 93.1 5.0 <0.020 <0.020 0.854 0.874 <0.010 <0.010 0.874 <0.010
08/12/15 ICR-05 1.0 0.044 9.30 99.5 20.0 6.50 <0.020 <0.020 1.000 1.020 <0.010 <0.010 1.020 <0.010
09/01/15 ICR-01 0.9 0.047 10.22 110.4 24.0 7.35 <0.020 <0.020 0.919 0.939 <0.010 <0.010 0.939 <0.010
09/01/15 ICR-01 17.8 0.047 8.81 94.1 15.0 0.022 <0.020 0.957 0.979 <0.010 <0.010 0.979 <0.010
09/01/15 ICR-01 36.0 0.056 7.03 74.6 13.0 0.065 0.043 0.932 0.997 <0.010 <0.010 0.997 0.014
09/01/15 ICR-03 0.9 0.050 10.32 111.5 23.0 7.65 0.054 0.043 1.176 1.230 <0.010 <0.010 1.230 <0.010
09/01/15 ICR-03 18.0 0.044 9.79 104.2 14.0 0.057 0.044 0.897 0.954 <0.010 <0.010 0.954 <0.010
09/01/15 ICR-05 1.0 0.051 10.33 111.1 26.0 5.40 0.048 0.038 1.032 1.080 <0.010 <0.010 1.080 <0.010
10/13/15 ICR-01 1.1 0.051 9.52 95.0 29.0 7.85 <0.020 <0.020 1.040 1.060 <0.010 <0.010 1.060 0.011
10/13/15 ICR-01 18.0 0.048 9.40 93.5 18.0 <0.020 <0.020 1.130 1.150 <0.010 <0.010 1.150 <0.010
10/13/15 ICR-01 36.0 0.049 8.95 88.8 16.0 <0.020 <0.020 1.020 1.040 <0.010 <0.010 1.040 <0.010
10/13/15 ICR-03 1.2 0.049 9.36 94.3 22.0 7.64 <0.020 <0.020 0.942 0.962 <0.010 <0.010 0.962 <0.010
10/13/15 ICR-03 21.3 0.043 8.29 81.4 11.0 0.020 <0.020 1.010 1.030 <0.010 <0.010 1.030 <0.010
10/13/15 ICR-05 1.1 0.042 8.90 89.2 14.0 7.10 0.020 <0.020 0.908 0.928 <0.010 <0.010 0.930 <0.010
11/18/15
12/15/15 ICR-01
Maximum 36.2 0.200 12.14 137.2 240.0 17.10 0.107 0.044 4.030 4.050 0.045 <0.010 4.050 0.025
Minimum 0.5 0.024 7.03 0.0 <2.0 3.20 <0.020 <0.020 0.696 0.724 <0.010 <0.010 0.724 <0.010
Average 12.8 0.045 9.74 93.8 19.9 7.85 0.031 0.022 0.992 1.023 0.013 <0.010 1.028 0.010
# Samples 54 54 54 55 54 25 54 54 54 54 54 54 54 54
Depth
Date Site Ft
01/13/15 ICR-01
02/11/15 ICR-01 0.9
02/11/15 ICR-01 21.0
02/11/15 ICR-01 36.0
02/11/15 ICR-03 0.9
02/11/15 ICR-03 21.0
02/11/15 ICR-05 0.9
03/18/15 ICR-01 0.9
03/18/15 ICR-01 18.0
03/18/15 ICR-01 36.0
03/18/15 ICR-03 0.9
03/18/15 ICR-03 12.0
03/18/15 ICR-05 0.9
04/21/15 ICR-01 3.0
04/21/15 ICR-01 17.9
04/21/15 ICR-01 36.0
04/21/15 ICR-03 2.6
04/21/15 ICR-03 18.0
04/21/15 ICR-05 0.9
05/20/15 ICR-01 0.5
05/20/15 ICR-01 18.1
05/20/15 ICR-01 36.2
05/20/15 ICR-03 0.5
05/20/15 ICR-03 21.1
05/20/15 ICR-05 0.5
06/17/15 ICR-01 0.9
06/17/15 ICR-01 18.0
06/17/15 ICR-01 36.0
06/17/15 ICR-03 0.9
06/17/15 ICR-03 21.0
06/17/15 ICR-05 1.0
07/14/15 ICR-01 0.5
07/14/15 ICR-01 18.0
07/14/15 ICR-01 36.0
07/14/15 ICR-03 0.5
07/14/15 ICR-03 21.0
07/14/15 ICR-05 0.5
08/12/15 ICR-01 0.9
08/12/15 ICR-01 18.0
08/12/15 ICR-01 36.0
08/12/15 ICR-03 0.9
08/12/15 ICR-03 21.0
08/12/15 ICR-05 1.0
09/01/15 ICR-01 0.9
09/01/15 ICR-01 17.8
09/01/15 ICR-01 36.0
09/01/15 ICR-03 0.9
09/01/15 ICR-03 18.0
09/01/15 ICR-05 1.0
10/13/15 ICR-01 1.1
10/13/15 ICR-01 18.0
10/13/15 ICR-01 36.0
10/13/15 ICR-03 1.2
10/13/15 ICR-03 21.3
10/13/15 ICR-05 1.1
11/18/15
12/15/15 ICR-01
Maximum 36.2
Minimum 0.5
Average 12.8
# Samples 54
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2015
Lake
Temp Alk MBAS COD BOD CL-TDS S.S.Turb EC Ca Na Mg SAR Level
C pH mg/l mg/l mg/l mg/l mg/l mg/l mg/l NTU uS/cm mg/l mg/l mg/l ft.
0.0
5.6 8.14 53.1 1.51 76 4.28 4.40 111
5.2 8.07 53.1 1.50 71 4.92 4.10 111
5.1 8.10 52.9 1.53 78 4.64 4.50 111
5.7 8.12 52.7 1.51 81 4.32 3.90 111
5.1 7.85 52.7 1.50 80 4.88 4.60 111
5.6 8.04 52.9 1.49 78 4.50 4.40 111
9.4 7.89 1.57 3.30 113
9.1 7.70 1.53 3.60 113
8.8 7.56 1.53 3.80 114
9.3 7.64 1.52 3.00 113
8.9 7.79 1.52 3.50 113
8.8 7.62 1.53 3.30 114
12.4 9.02 1.36 2.30 115
11.9 9.02 1.39 3.00 115
11.1 8.87 1.37 3.30 115
12.4 9.03 1.36 2.60 115
10.8 8.97 1.36 3.00 116
12.4 9.00 1.36 2.60 115
13.0 9.33 52.5 1.29 73 0.84 0.82 112
12.6 9.48 52.5 1.29 75 1.06 0.91 112
12.3 9.40 52.7 1.31 70 1.12 1.00 112
13.1 9.49 52.7 1.29 72 0.72 0.96 112
12.3 9.54 52.5 1.28 74 0.89 0.99 111
12.8 9.46 52.8 1.28 72 1.01 0.78 111
19.9 9.55 1.18 0.79 110
19.4 9.61 1.16 0.76 110
18.8 9.52 1.17 0.88 109
20.0 9.60 1.15 0.64 110
18.9 9.65 1.16 0.69 110
20.0 9.64 1.16 0.56 110
21.4 9.84 1.27 33.00 114
19.2 9.37 1.26 1.30 108
18.8 9.26 1.24 1.70 108
21.2 9.83 1.26 28.00 114
19.0 9.38 1.26 1.00 108
21.0 9.67 1.25 13.00 112
19.4 9.64 49.5 1.25 82 3.53 4.80 111
18.9 9.81 49.2 1.23 71 3.19 2.80 110
18.5 9.78 49.4 1.25 77 4.94 2.20 109
19.3 9.71 49.4 1.23 78 3.54 4.30 111
18.3 9.74 49.2 1.23 76 2.43 2.80 109
18.6 9.82 49.9 1.22 74 3.91 4.70 110
19.1 9.87 1.32 3.00 114
18.5 9.87 1.30 2.50 111
18.3 9.74 1.30 3.70 109
19.1 10.03 1.29 2.20 114
18.4 9.97 1.30 2.70 112
18.9 10.01 1.29 3.10 113
15.3 9.08 1.52 2.50 109
15.1 9.15 1.52 2.40 109
15.0 9.16 1.52 2.10 109
15.7 9.26 1.50 1.30 110
14.5 9.14 1.49 2.00 109
15.5 9.24 1.50 1.60 110
21.4 10.03 53.1 0.0 0.00 1.57 82 4.94 33.00 116 0.00 0.00 0.00 0.00 0.00
0.0 7.56 49.2 0.0 0.00 1.15 70 0.72 0.56 108 0.00 0.00 0.00 0.00 0.00
14.3 9.13 51.7 1.35 75 3.04 3.73 111
55 54 18 0 0 54 18 18 54 54 0 0 0 0 0
Depth
Date Site Ft
01/13/15 ICR-01
02/11/15 ICR-01 0.9
02/11/15 ICR-01 21.0
02/11/15 ICR-01 36.0
02/11/15 ICR-03 0.9
02/11/15 ICR-03 21.0
02/11/15 ICR-05 0.9
03/18/15 ICR-01 0.9
03/18/15 ICR-01 18.0
03/18/15 ICR-01 36.0
03/18/15 ICR-03 0.9
03/18/15 ICR-03 12.0
03/18/15 ICR-05 0.9
04/21/15 ICR-01 3.0
04/21/15 ICR-01 17.9
04/21/15 ICR-01 36.0
04/21/15 ICR-03 2.6
04/21/15 ICR-03 18.0
04/21/15 ICR-05 0.9
05/20/15 ICR-01 0.5
05/20/15 ICR-01 18.1
05/20/15 ICR-01 36.2
05/20/15 ICR-03 0.5
05/20/15 ICR-03 21.1
05/20/15 ICR-05 0.5
06/17/15 ICR-01 0.9
06/17/15 ICR-01 18.0
06/17/15 ICR-01 36.0
06/17/15 ICR-03 0.9
06/17/15 ICR-03 21.0
06/17/15 ICR-05 1.0
07/14/15 ICR-01 0.5
07/14/15 ICR-01 18.0
07/14/15 ICR-01 36.0
07/14/15 ICR-03 0.5
07/14/15 ICR-03 21.0
07/14/15 ICR-05 0.5
08/12/15 ICR-01 0.9
08/12/15 ICR-01 18.0
08/12/15 ICR-01 36.0
08/12/15 ICR-03 0.9
08/12/15 ICR-03 21.0
08/12/15 ICR-05 1.0
09/01/15 ICR-01 0.9
09/01/15 ICR-01 17.8
09/01/15 ICR-01 36.0
09/01/15 ICR-03 0.9
09/01/15 ICR-03 18.0
09/01/15 ICR-05 1.0
10/13/15 ICR-01 1.1
10/13/15 ICR-01 18.0
10/13/15 ICR-01 36.0
10/13/15 ICR-03 1.2
10/13/15 ICR-03 21.3
10/13/15 ICR-05 1.1
11/18/15
12/15/15 ICR-01
Maximum 36.2
Minimum 0.5
Average 12.8
# Samples 54
% Ice
Cover
90
0
0
0
0
0
0
0
0
0
90
90
0
16
11
Depth
Date Site Ft
01/13/15 ICR-01
02/11/15 ICR-01 0.9
02/11/15 ICR-01 21.0
02/11/15 ICR-01 36.0
02/11/15 ICR-03 0.9
02/11/15 ICR-03 21.0
02/11/15 ICR-05 0.9
03/18/15 ICR-01 0.9
03/18/15 ICR-01 18.0
03/18/15 ICR-01 36.0
03/18/15 ICR-03 0.9
03/18/15 ICR-03 12.0
03/18/15 ICR-05 0.9
04/21/15 ICR-01 3.0
04/21/15 ICR-01 17.9
04/21/15 ICR-01 36.0
04/21/15 ICR-03 2.6
04/21/15 ICR-03 18.0
04/21/15 ICR-05 0.9
05/20/15 ICR-01 0.5
05/20/15 ICR-01 18.1
05/20/15 ICR-01 36.2
05/20/15 ICR-03 0.5
05/20/15 ICR-03 21.1
05/20/15 ICR-05 0.5
06/17/15 ICR-01 0.9
06/17/15 ICR-01 18.0
06/17/15 ICR-01 36.0
06/17/15 ICR-03 0.9
06/17/15 ICR-03 21.0
06/17/15 ICR-05 1.0
07/14/15 ICR-01 0.5
07/14/15 ICR-01 18.0
07/14/15 ICR-01 36.0
07/14/15 ICR-03 0.5
07/14/15 ICR-03 21.0
07/14/15 ICR-05 0.5
08/12/15 ICR-01 0.9
08/12/15 ICR-01 18.0
08/12/15 ICR-01 36.0
08/12/15 ICR-03 0.9
08/12/15 ICR-03 21.0
08/12/15 ICR-05 1.0
09/01/15 ICR-01 0.9
09/01/15 ICR-01 17.8
09/01/15 ICR-01 36.0
09/01/15 ICR-03 0.9
09/01/15 ICR-03 18.0
09/01/15 ICR-05 1.0
10/13/15 ICR-01 1.1
10/13/15 ICR-01 18.0
10/13/15 ICR-01 36.0
10/13/15 ICR-03 1.2
10/13/15 ICR-03 21.3
10/13/15 ICR-05 1.1
11/18/15
12/15/15 ICR-01
Maximum 36.2
Minimum 0.5
Average 12.8
# Samples 54
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2015
Coliforms Fecal Air
Total Fecal/E. coli Strep Temp SO4 Boron Fe Mn
Algae Weeds MPN MPN MPN C mg/L mg/L ug/L ug/L
Yes No 7.5 3.35
3.21
2.98
50 <1 2.82
2.80
54 <1 2.80
Yes No 2 <1 12.0 2.42
3.35
2.60
<1 <1 3.11
3.09
1 <1 4.12
Yes No 5 <1 20.1 1.51
1.51
1.51
7 1 1.51
1.51
2 <1 1.51
No No 5 <1 14.0 2.56
2.60
2.63
3 <1 2.62
2.52
2 <1 2.57
Yes Yes 43 <1 22.4 2.53
2.74
2.70
38 <1 2.79
2.72
172 <1 2.80
Yes Yes 14 <1 2.43
2.99
2.99
12 <1 2.93
2.81
2.84
Yes Yes >2419 <1 22.5 2.41
2.95
2.99
>2419 <1 3.00
2.74
>2419 <1 2.78
Yes Yes 411 <1 22.4 2.46
2.61
2.59
238 <1 2.62
2.58
276 <1 2.59
Yes Yes 70 3 21.5 3.10
3.06
3.00
57 2 3.01
4.05
127 44 2.99
>2419 44 0 22.5 4.12
<1 <1 0 7.5 1.51
354 3 17.8 2.70
55 55 25 25 0 8 54 0 0 0
Depth
Date Site Ft
01/13/15 ICR-01
02/11/15 ICR-01 0.9
02/11/15 ICR-01 21.0
02/11/15 ICR-01 36.0
02/11/15 ICR-03 0.9
02/11/15 ICR-03 21.0
02/11/15 ICR-05 0.9
03/18/15 ICR-01 0.9
03/18/15 ICR-01 18.0
03/18/15 ICR-01 36.0
03/18/15 ICR-03 0.9
03/18/15 ICR-03 12.0
03/18/15 ICR-05 0.9
04/21/15 ICR-01 3.0
04/21/15 ICR-01 17.9
04/21/15 ICR-01 36.0
04/21/15 ICR-03 2.6
04/21/15 ICR-03 18.0
04/21/15 ICR-05 0.9
05/20/15 ICR-01 0.5
05/20/15 ICR-01 18.1
05/20/15 ICR-01 36.2
05/20/15 ICR-03 0.5
05/20/15 ICR-03 21.1
05/20/15 ICR-05 0.5
06/17/15 ICR-01 0.9
06/17/15 ICR-01 18.0
06/17/15 ICR-01 36.0
06/17/15 ICR-03 0.9
06/17/15 ICR-03 21.0
06/17/15 ICR-05 1.0
07/14/15 ICR-01 0.5
07/14/15 ICR-01 18.0
07/14/15 ICR-01 36.0
07/14/15 ICR-03 0.5
07/14/15 ICR-03 21.0
07/14/15 ICR-05 0.5
08/12/15 ICR-01 0.9
08/12/15 ICR-01 18.0
08/12/15 ICR-01 36.0
08/12/15 ICR-03 0.9
08/12/15 ICR-03 21.0
08/12/15 ICR-05 1.0
09/01/15 ICR-01 0.9
09/01/15 ICR-01 17.8
09/01/15 ICR-01 36.0
09/01/15 ICR-03 0.9
09/01/15 ICR-03 18.0
09/01/15 ICR-05 1.0
10/13/15 ICR-01 1.1
10/13/15 ICR-01 18.0
10/13/15 ICR-01 36.0
10/13/15 ICR-03 1.2
10/13/15 ICR-03 21.3
10/13/15 ICR-05 1.1
11/18/15
12/15/15 ICR-01
Maximum 36.2
Minimum 0.5
Average 12.8
# Samples 54
Comments
Data sonde broken
Frozen