HomeMy WebLinkAbout2016 ICR TMDL Status Rpt_03.02.2017
South Tahoe Public Utility District Indian Creek Reservoir TMDL Progress Report for 2016
3/2/2017
1
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 2016 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 from Indian Creek and diversions from the West Fork of
the Carson River (WFCR). During 2016, the inflow of fresh water from the WFCR is about 828 AF (Figure
2). This is about 95% of the average volume of fresh water inflow from the WFCR over the preceding five
year period (2011 – 2015).
2
Figure 2. Fresh water inflow from the West Fork of the Carson River to Indian Creek Reservoir,
measured at the District’s Upper Dressler Ditch Parshall flume (in acre-feet).
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.
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
2011 2012 2013 2014 2015 2016
VO
L
U
M
E
(
a
c
r
e
-fe
e
t
)
WATER YEAR
UPPER DRESSLER DITCH FLUME
Annual Discharge
3
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
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
4
• 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 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. The added air
receiver volume allows for increased flow and air pressure through the Air Sep AS-450 resulting in
increased oxygen production ( lbs/day) for delivery to the Speece Cone.
The onsite oxygen generator is housed within an equipment building which also 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 August 2012, the District installed new ductwork to better exhaust the discharge
from the air compressor; thereby reducing the heat load in the building.
The HOS is operated during the late spring and summer to provide oxygen to ICR for water quality and
aquatic habitat improvement. 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. The
operating periods, run times, total pounds of oxygen produced and generation rates for each year of
operations are listed in Table 2.
5
During 2016, the oxygen generator ran at about 63% of its output capacity over a 170 day operating
period, producing 74,773 pounds (lbs.) of oxygen for delivery to ICR at an average production rate of
440 pounds per day (lbs/day). The output capacity and accompanying production rate for the oxygen
generator were significantly below the preceding 5-years of operations (2011 – 2015) averages of 80%
output capacity and 524 lbs/day production rate. The abnormally low output capacity resulted from an
extended period of down time due to the air compressor overheating. This occurred for nearly two
months from early June until the air compressor was serviced and repaired in early August. This period
of abnormally low oxygen production is clearly evident in Figure 3.
YEAR OPERATING PERIOD RUN TIME TOTAL O2
PRODUCED
AVERAGE O2
PRODUCTION RATE
Start Date End Date (hrs.)(lbs.) (lbs/day)
Table 2. Operating period and oxygen production for the on-site oxygen generation system.
Figure 3. Pounds of oxygen produced by the on-site oxygen generation system during the 2016
operating period.
0
25,000
50,000
75,000
100,000
Ox
y
g
e
n
M
a
s
s
,
i
n
l
b
s
O
2
ICR OXYGEN PRODUCTION
6
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
2016, approximately $16,900 was expended by the District for 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
$2,841 $14,056 $16,897
Table 3. ICR HOS annual construction, operation and monitoring costs.
7
4 ICR TMDL Monitoring
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 2016 raw water samples are provided in Appendix A. The
indicator parameter results are summarized in Table 4.
Figure 4. ICRTMDL reservoir station sites.
8
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 6.
(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 2016 Summary of Results.
9
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. Figure 5 shows
that TP annual mean remained at or below the target level of 0.04 mg/L from 2010 through 2014.
During 2015, the TP annual mean increased slightly above the target level to 0.045 mg/L. In 2016, the TP
annual mean declined to 0.03 mg/L; below the target level.
Figure 5. Total phosphorus levels at ICR, plotted as an annual mean, in milligrams per liter (mg/L).
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 2016
AN
N
U
A
L
M
E
A
N
(
m
g
/
L
)
INDIAN CREEK RESERVOIR
TOTAL PHOSPHORUS
Interim Target (≤ 0.04 mg/L)
10
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, DO readings collected through the water column at each site (ICR-1, ICR-3 and ICR-5) were
averaged and plotted as a daily mean for each month of the year. Figure 6 shows that daily mean DO
levels were greater than 4.0 mg/L at each site for each monitoring day during 2016.Note that the lowest
DO readings were measured near the end of the 2-month period when the oxygenation system was not
operating (Section 3).
Figure 6. 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 2016. Figure 7 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
14.00
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)
11
Figure 7. Daily mean dissolved oxygen levels measured at ICR (2007 through 2016), 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. Figure 8 shows that, since 2010, summer mean SD levels have
increased to greater than 2.0 meters. During 2016, summer mean SD (3.42 meters) increased compared
to the previous year’s summer mean (2.66 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)
12
Figure 8. Summer mean secchi depth readings measured at ICR during June, July and August (2007
through 2016), 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 (Figure 9). Prior to statistical evaluation, an imputed value of one-half the
method detection level (MDL) was substituted for Chl-a values below the MDL. Figure 9 shows that,
since 2008, Chl-a levels have been decreasing and have been less than 10 mg/m3 in 2012 and 2013. In
2014, the Chl-a summer mean value (10.9 mg/m3) increased slightly above the TMDL target level and
further increased during 2015 (34.7 mg/m3). In 2016, Chl-a levels decreased again below target levels to
a summer mean value of 4.2 mg/m3.
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 2016
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)
13
Figure 9. Summer mean chlorophyll-a concentrations measured at ICR during June, July and August
(2007 through 2016), in milligrams per cubic meter (mg/m3).
5.5 Trophic State Index
The ICR TMDL Tracking Plan requires that the summer (June, July and August) TP, SD and Chl-a values
are 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. Figure 10 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. During 2014 and 2015 TSI (SD), TSI (Chl-a) and TSI (TP) summer
values increased to above TMDL Target levels. In 2016, TSI (SD)(42 units) and TSI (Chl-a) (40 units)
summer values fell below TMDL Target levels; while TSI (TP) (53 units) summer values remained above
TMDL Target levels.
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
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
Figure 10. Carlson trophic state index (TSI) values for sechhi depth, chlorophyll-a, and total phosphorus,
during June, July and August (2007 through 2016), in TSI units.
25
30
35
40
45
50
55
60
65
70
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
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)
15
6 Summary & Conclusions
Evaluation of the 2016 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 0.03
mg/L, in compliance with TMDL interim target levels.
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
3.42 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 4.2 mg/m3, in compliance with TMDL numeric targets.
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) = 53; TSI (SD) = 42; and TSI (Chl-a) = 40.
The TSI (SD) and TSI (Chl-a) are in compliance with TMDL numeric targets; while TSI (TP) exceeds
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.
16
APPENDIX A
ANALYTICAL RESULTS
2016 ICR WATER QUALITY DATA
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2016
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
02/10/16 ICR-01 0.5 0.037 11.40 86.3 7.0 7.50 0.068 <0.020 0.758 0.826 0.110 <0.010 0.936 0.011
02/10/16 ICR-01 18.0 0.045 11.40 86.1 5.0 0.067 <0.020 0.693 0.760 0.110 <0.010 0.870 0.012
02/10/16 ICR-01 36.0 0.034 11.30 85.4 4.0 0.067 <0.020 0.669 0.736 0.113 <0.010 0.849 0.012
02/10/16 ICR-03 0.5 0.036 11.60 90.5 6.0 6.81 0.056 <0.020 0.673 0.729 0.109 <0.010 0.838 0.011
02/10/16 ICR-03 21.0 0.042 11.40 87.1 6.0 0.059 <0.020 0.706 0.765 0.108 <0.010 0.873 0.012
02/10/16 ICR-05 0.5 0.034 11.70 90.7 6.0 6.90 0.051 <0.020 0.632 0.683 0.106 <0.010 0.789 0.011
03/16/16 ICR-01 0.5 0.026 11.80 96.8 3.0 11.30 0.036 <0.020 0.573 0.609 0.042 <0.010 0.651 <0.010
03/16/16 ICR-01 21.0 0.034 11.70 96.6 4.0 0.025 <0.020 0.607 0.632 0.042 <0.010 0.674 <0.010
03/16/16 ICR-01 42.0 0.029 7.54 61.4 4.0 0.025 <0.020 0.675 0.700 0.039 <0.010 0.739 <0.010
03/16/16 ICR-03 0.5 0.029 11.90 97.7 3.0 9.70 0.032 <0.020 0.632 0.664 0.039 <0.010 0.703 <0.010
03/16/16 ICR-03 24.0 0.031 11.60 93.9 3.0 0.031 <0.020 0.614 0.645 0.043 <0.010 0.688 <0.010
03/16/16 ICR-05 0.5 0.033 11.80 97.1 3.0 9.65 0.025 <0.020 0.638 0.663 0.042 <0.010 0.705 <0.010
04/12/16 ICR-01 0.5 0.026 8.91 83.3 4.0 12.75 0.041 <0.020 0.563 0.604 0.016 <0.010 0.620 <0.010
04/12/16 ICR-01 18.0 0.031 8.47 76.6 3.0 0.045 <0.020 0.563 0.608 0.020 <0.010 0.628 <0.010
04/12/16 ICR-01 36.0 0.034 7.08 60.9 3.0 0.078 <0.020 0.556 0.634 0.049 <0.010 0.683 0.014
04/12/16 ICR-03 0.5 0.025 8.97 83.2 4.0 10.54 0.040 <0.020 0.606 0.646 0.015 <0.010 0.661 <0.010
04/12/16 ICR-03 21.0 0.026 8.55 76.9 3.0 0.039 <0.020 0.496 0.535 0.015 <0.010 0.550 <0.010
04/12/16 ICR-05 0.5 0.026 8.97 82.6 4.0 10.73 0.041 <0.020 0.566 0.607 0.015 <0.010 0.622 <0.010
05/10/16 ICR-01 0.5 0.023 10.74 104.9 2.0 14.05 <0.020 <0.020 0.619 0.619 <0.010 <0.010 0.619 <0.010
05/10/16 ICR-01 18.0 0.025 11.40 107.5 2.0 <0.020 <0.020 0.567 0.567 <0.010 <0.010 0.567 <0.010
05/10/16 ICR-01 36.0 0.033 10.78 100.7 <2.0 <0.020 <0.020 0.645 0.645 <0.010 <0.010 0.645 <0.010
05/10/16 ICR-03 0.5 0.023 10.69 105.1 4.0 12.40 0.020 <0.020 0.584 0.604 <0.010 <0.010 0.604 <0.010
05/10/16 ICR-03 21.0 0.021 11.87 112.2 <2.0 <0.020 <0.020 0.587 0.587 <0.010 <0.010 0.587 <0.010
05/10/16 ICR-05 0.5 0.023 10.96 107.4 <2.0 13.20 <0.020 <0.020 0.628 0.628 <0.010 <0.010 0.628 <0.010
06/22/16 ICR-01 0.5 0.026 8.99 95.8 8.0 10.80 <0.020 <0.020 0.508 0.508 <0.010 <0.010 0.508 <0.010
06/22/16 ICR-01 14.0 0.023 8.99 95.5 5.0 <0.020 <0.020 0.516 0.516 <0.010 <0.010 0.516 <0.010
06/22/16 ICR-01 38.8 0.031 7.71 78.5 <2.0 0.053 <0.020 0.447 0.500 <0.010 <0.010 0.500 0.012
06/22/16 ICR-03 0.5 0.021 9.04 95.5 <2.0 0.023 <0.020 0.436 0.459 <0.010 <0.010 0.459 <0.010
06/22/16 ICR-03 26.0 0.023 7.68 78.4 <2.0 0.035 <0.020 0.448 0.483 <0.010 <0.010 0.483 0.010
06/22/16 ICR-05 0.5 0.020 9.19 97.0 <2.0 <0.020 <0.020 0.477 0.477 <0.010 <0.010 0.477 <0.010
07/14/16 ICR-01 0.5 0.029 9.44 104.4 7.0 14.40 0.021 <0.020 0.614 0.635 <0.010 <0.010 0.635 <0.010
07/14/16 ICR-01 21.0 0.031 8.88 95.8 <2.0 0.028 <0.020 0.527 0.555 <0.010 <0.010 0.555 <0.010
07/14/16 ICR-01 39.0 0.044 8.09 86.9 <2.0 0.061 <0.020 0.629 0.690 0.010 <0.010 0.700 <0.010
07/14/16 ICR-03 0.5 0.028 9.49 104.8 9.0 12.40 <0.020 <0.020 0.588 0.588 0.048 <0.010 0.636 <0.010
07/14/16 ICR-03 24.0 0.030 9.14 98.7 2.0 0.028 <0.020 0.508 0.536 0.010 <0.010 0.546 <0.010
07/14/16 ICR-05 0.5 0.028 9.83 109.2 7.0 10.80 <0.020 <0.020 0.594 0.594 <0.010 <0.010 0.594 <0.010
08/03/16 ICR-01 0.5 0.029 7.88 90.8 8.0 9.25 <0.020 <0.020 0.641 0.641 <0.010 <0.010 0.641 <0.010
08/03/16 ICR-01 21.0 0.024 5.44 58.9 <2.0 0.055 <0.020 0.456 0.511 <0.010 <0.010 0.511 <0.010
08/03/16 ICR-01 39.0 0.135 0.49 5.3 <2.0 0.339 <0.020 0.527 0.866 0.012 <0.010 0.878 0.062
08/03/16 ICR-03 0.5 0.028 7.95 91.4 13.0 10.23 <0.020 <0.020 0.665 0.665 <0.010 <0.010 0.665 <0.010
08/03/16 ICR-03 24.0 0.042 3.75 40.4 3.0 0.106 <0.020 0.458 0.564 0.015 <0.010 0.579 0.018
08/03/16 ICR-05 0.5 0.024 8.10 92.5 5.0 10.74 <0.020 <0.020 0.673 0.673 <0.010 <0.010 0.673 <0.010
09/15/16 ICR-01 1.1 0.034 9.69 99.3 14.0 8.65 <0.020 <0.020 0.770 0.770 <0.010 <0.010 0.770 <0.010
09/15/16 ICR-01 17.7 0.036 9.65 98.4 18.0 <0.020 <0.020 0.757 0.757 <0.010 <0.010 0.757 <0.010
09/15/16 ICR-01 36.1 0.038 9.38 95.1 9.0 <0.020 <0.020 0.807 0.807 <0.010 <0.010 0.807 <0.010
09/15/16 ICR-03 1.1 0.034 9.67 99.4 16.0 8.30 <0.020 <0.020 0.752 0.752 <0.010 <0.010 0.752 <0.010
09/15/16 ICR-03 21.2 0.039 9.40 95.7 15.0 <0.020 <0.020 0.833 0.833 <0.010 <0.010 0.833 <0.010
09/15/16 ICR-05 1.0 0.039 9.53 97.6 15.0 8.70 <0.020 <0.020 0.809 0.809 <0.010 <0.010 0.809 <0.010
10/26/16 ICR-01 0.5 Too windy
11/03/16 ICR-01 0.5 0.055 9.67 82.9 130.0 4.50 <0.020 <0.020 1.520 1.520 0.020 <0.010 1.540 <0.010
11/03/16 ICR-01 18.0 0.052 9.31 79.4 36.0 <0.020 <0.020 1.120 1.120 0.015 <0.010 1.140 <0.010
11/03/16 ICR-01 36.0 0.040 9.27 78.9 39.0 <0.020 <0.020 0.977 0.977 0.013 <0.010 0.990 <0.010
11/03/16 ICR-03 0.5 0.041 9.37 80.0 45.0 6.39 0.025 <0.020 0.927 0.952 0.013 <0.010 0.965 <0.010
11/03/16 ICR-03 21.0 0.039 9.21 78.5 25.0 0.022 <0.020 0.928 0.950 0.014 <0.010 0.964 <0.010
11/03/16 ICR-05 0.5 0.033 9.34 79.6 24.0 5.95 0.030 <0.020 0.887 0.917 0.013 <0.010 0.930 <0.010
12/28/16 ICR-01 Frozen
Maximum 42.0 0.135 11.90 112.2 130.0 14.40 0.339 0.020 1.520 1.520 0.113 <0.010 1.540 0.062
Minimum 0.5 0.020 0.49 5.3 <2.0 4.50 <0.020 <0.020 0.436 0.459 <0.010 <0.010 0.459 <0.010
Average 13.2 0.034 9.37 88.1 10.3 9.87 0.039 0.020 0.660 0.691 0.027 <0.010 0.714 0.011
# Samples 55 54 54 54 54 25 54 54 54 54 54 54 54 54
Depth
Date Site Ft
02/10/16 ICR-01 0.5
02/10/16 ICR-01 18.0
02/10/16 ICR-01 36.0
02/10/16 ICR-03 0.5
02/10/16 ICR-03 21.0
02/10/16 ICR-05 0.5
03/16/16 ICR-01 0.5
03/16/16 ICR-01 21.0
03/16/16 ICR-01 42.0
03/16/16 ICR-03 0.5
03/16/16 ICR-03 24.0
03/16/16 ICR-05 0.5
04/12/16 ICR-01 0.5
04/12/16 ICR-01 18.0
04/12/16 ICR-01 36.0
04/12/16 ICR-03 0.5
04/12/16 ICR-03 21.0
04/12/16 ICR-05 0.5
05/10/16 ICR-01 0.5
05/10/16 ICR-01 18.0
05/10/16 ICR-01 36.0
05/10/16 ICR-03 0.5
05/10/16 ICR-03 21.0
05/10/16 ICR-05 0.5
06/22/16 ICR-01 0.5
06/22/16 ICR-01 14.0
06/22/16 ICR-01 38.8
06/22/16 ICR-03 0.5
06/22/16 ICR-03 26.0
06/22/16 ICR-05 0.5
07/14/16 ICR-01 0.5
07/14/16 ICR-01 21.0
07/14/16 ICR-01 39.0
07/14/16 ICR-03 0.5
07/14/16 ICR-03 24.0
07/14/16 ICR-05 0.5
08/03/16 ICR-01 0.5
08/03/16 ICR-01 21.0
08/03/16 ICR-01 39.0
08/03/16 ICR-03 0.5
08/03/16 ICR-03 24.0
08/03/16 ICR-05 0.5
09/15/16 ICR-01 1.1
09/15/16 ICR-01 17.7
09/15/16 ICR-01 36.1
09/15/16 ICR-03 1.1
09/15/16 ICR-03 21.2
09/15/16 ICR-05 1.0
10/26/16 ICR-01 0.5
11/03/16 ICR-01 0.5
11/03/16 ICR-01 18.0
11/03/16 ICR-01 36.0
11/03/16 ICR-03 0.5
11/03/16 ICR-03 21.0
11/03/16 ICR-05 0.5
12/28/16 ICR-01
Maximum 42.0
Minimum 0.5
Average 13.2
# Samples 55
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2016
Lake
Temp Alk MBAS COD BOD CL-TDS S.S.Turb EC Ca Na Mg SAR Level % Ice
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.Cover Algae Weeds
3.8 7.90 50.3 1.77 78 1.37 2.80 104 0 No yes
3.7 7.82 49.9 1.75 78 1.69 2.80 104
3.8 7.66 50.1 1.74 76 1.64 2.80 104
4.8 7.94 49.9 1.74 76 1.84 3.00 104
3.9 7.93 50.3 1.72 79 1.71 2.90 104
4.6 7.96 50.7 1.75 77 1.89 3.10 103
7.9 6.81 2.14 2.50 101 0 Yes No
7.8 6.66 2.15 2.30 101
7.8 6.56 2.07 2.40 102
8.0 6.98 2.03 2.20 101
7.9 6.44 2.03 2.40 101
7.9 7.06 2.02 2.20 101
12.4 7.83 2.25 1.80 99 0 Yes No
10.9 7.95 2.22 1.90 98
8.7 7.67 2.24 2.40 103
12.0 8.00 2.19 1.80 99
10.6 7.92 2.16 1.90 98
11.7 7.90 2.16 1.80 99
14.3 8.63 45.4 1.54 66 0.54 1.40 94 0 Yes Yes
12.7 8.41 45.0 1.54 68 0.65 1.30 94
12.3 8.43 45.0 1.54 76 0.82 1.50 94
14.6 8.95 44.8 1.55 70 0.91 1.30 95
12.8 8.96 44.6 1.50 67 0.56 1.30 93
14.4 8.96 44.9 1.55 59 0.50 1.30 94
18.4 7.24 1.37 1.20 94 0 Yes No
18.3 7.76 1.36 1.10 94
16.2 7.20 1.36 1.30 94
18.0 8.16 1.36 0.82 94
16.3 7.71 1.36 0.97 94
17.9 7.98 1.36 1.10 94
20.3 8.87 1.37 1.60 98 0 Yes Yes
19.0 8.73 1.39 1.10 97
18.8 8.57 1.34 1.20 98
20.2 8.91 1.43 1.60 98
19.1 8.79 1.36 1.20 97
20.5 9.04 1.35 1.80 97
22.4 9.23 47.3 1.35 71 1.90 2.50 100 0 Yes Yes
19.2 8.39 46.6 1.31 66 0.44 0.71 98
18.5 7.61 50.0 1.34 75 1.68 1.80 106
22.3 9.22 47.2 1.38 67 2.36 4.00 99
18.9 8.07 47.8 1.32 68 0.38 1.00 100
21.9 9.24 47.2 1.33 67 1.10 1.90 99
16.5 9.50 1.33 2.20 101 0 Yes Yes
16.3 9.42 1.33 2.10 101
16.0 9.33 1.31 3.80 100
16.7 9.41 1.33 3.20 101
16.2 9.40 1.33 3.80 101
16.5 9.44 1.34 2.60 101
0
8.6 8.71 49.0 1.64 76 8.10 8.60 102 0 Yes Yes
8.4 8.65 49.4 1.65 81 6.38 4.70 102
8.3 8.57 48.8 1.63 78 4.48 3.30 102
8.4 8.56 49.4 1.66 75 5.50 3.40 102
8.4 8.61 49.0 1.66 78 4.46 2.80 102
8.3 8.22 49.3 1.66 77 4.60 3.40 102
80
22.4 9.50 50.7 0.0 0.00 2.25 81 8.10 8.60 106 0.00 0.00 0.00 0.00 0.00 80
3.7 6.44 44.6 0.0 0.00 1.31 59 0.38 0.71 93 0.00 0.00 0.00 0.00 0.00 0
13.2 8.26 48.0 1.62 73 2.31 2.26 99 7
54 54 24 0 0 54 24 24 54 54 0 0 0 0 0 11 56 56
Depth
Date Site Ft
02/10/16 ICR-01 0.5
02/10/16 ICR-01 18.0
02/10/16 ICR-01 36.0
02/10/16 ICR-03 0.5
02/10/16 ICR-03 21.0
02/10/16 ICR-05 0.5
03/16/16 ICR-01 0.5
03/16/16 ICR-01 21.0
03/16/16 ICR-01 42.0
03/16/16 ICR-03 0.5
03/16/16 ICR-03 24.0
03/16/16 ICR-05 0.5
04/12/16 ICR-01 0.5
04/12/16 ICR-01 18.0
04/12/16 ICR-01 36.0
04/12/16 ICR-03 0.5
04/12/16 ICR-03 21.0
04/12/16 ICR-05 0.5
05/10/16 ICR-01 0.5
05/10/16 ICR-01 18.0
05/10/16 ICR-01 36.0
05/10/16 ICR-03 0.5
05/10/16 ICR-03 21.0
05/10/16 ICR-05 0.5
06/22/16 ICR-01 0.5
06/22/16 ICR-01 14.0
06/22/16 ICR-01 38.8
06/22/16 ICR-03 0.5
06/22/16 ICR-03 26.0
06/22/16 ICR-05 0.5
07/14/16 ICR-01 0.5
07/14/16 ICR-01 21.0
07/14/16 ICR-01 39.0
07/14/16 ICR-03 0.5
07/14/16 ICR-03 24.0
07/14/16 ICR-05 0.5
08/03/16 ICR-01 0.5
08/03/16 ICR-01 21.0
08/03/16 ICR-01 39.0
08/03/16 ICR-03 0.5
08/03/16 ICR-03 24.0
08/03/16 ICR-05 0.5
09/15/16 ICR-01 1.1
09/15/16 ICR-01 17.7
09/15/16 ICR-01 36.1
09/15/16 ICR-03 1.1
09/15/16 ICR-03 21.2
09/15/16 ICR-05 1.0
10/26/16 ICR-01 0.5
11/03/16 ICR-01 0.5
11/03/16 ICR-01 18.0
11/03/16 ICR-01 36.0
11/03/16 ICR-03 0.5
11/03/16 ICR-03 21.0
11/03/16 ICR-05 0.5
12/28/16 ICR-01
Maximum 42.0
Minimum 0.5
Average 13.2
# Samples 55
SOUTH TAHOE PUBLIC UTILITY DISTRICT
INDIAN CREEK RESERVOIR DATA SUMMARY
2016
Coliforms Fecal Air
Total Fecal/E. coli Strep Temp SO4 Boron Fe Mn
MPN MPN MPN C mg/L mg/L ug/L ug/L Comments
35 <1 13.4 3.26
3.26
3.42
33 <1 3.41
3.24
19 <1 3.31
12 <1 7.8 3.29
3.03
3.28
15 <1 3.39
3.24
16 1 3.19
37 <1 14.2 3.60
3.44
3.55
23 <1 3.27
3.60
25 <1 2.94
63 1 14.5 3.43
3.17
2.92
96 <1 2.84
2.96
23 <1 3.16
435 <1 24.5 2.45
2.56
2.52
214 <1 2.68
2.51
345 1 3.66
43 <1 26.1 1.90
3.37
3.80
28 <1 3.83
4.37
99 1 3.92
>2419 <1 22.4 3.10
3.24
2.97
>2419 <1 3.17
3.65
>2419 <1 3.90
86 <1 18.6 5.73
1.89
1.76
72 <1 1.86
1.84
140 1 1.80
Too windy to sample
32 2 7.1 2.70
2.50
2.63
23 1 2.70
2.60
43 5 2.60
Frozen
>2419 5 0 26.1 5.73
<12 <1 0 7.1 1.76
341 1 16.5 3.08
27 27 0 9 54 0 0 0