Sammamish River Diel pH and Dissolved Oxygen Study · Sammamish River Diel pH and Dissolved Oxygen Study King County i March 2005 Acknowledgements The results and analyses presented

Sammamish River Diel pH and Dissolved Oxygen Study

March 2005

Alternate Formats Available 206-296-7380 TTY Relay: 711


Submitted by: Curtis DeGasperi King County Water and Land Resources Division Department of Natural Resources and Parks

Department of Natural Resources and ParksWater and Land Resources Division201 S Jackson St. Ste 600Seattle, WA 98104(206) 296-6519


King County i March 2005

Acknowledgements The results and analyses presented in this report were the result of work and support provided by a diverse group of researchers, technicians, and project managers. Special thanks to Doug Houck (King County Wastewater Treatment Division) and David Robinson (King County Environmental Sampling Services) for use of and assistance with the maintenance and trouble shooting of the YSI sondes. The report greatly benefited from critical reviews by Betsy Cooper (King County Wastewater Treatment Division), Doug Houck, and Mindy Roberts (Washington State Department of Ecology).

Citation King County. 2005. Sammamish River Diel pH and Dissolved Oxygen Study. Prepared by

Curtis DeGasperi, Water and Land Resources Division. Seattle, Washington.


King County ii March 2005

Table of Contents Executive Summary ....................................................................................................................... iv

1.0. Introduction......................................................................................................................... 1

1.1 Study Area ...................................................................................................................... 1

1.2 Project Background......................................................................................................... 3

1.3 Goals and Objectives ...................................................................................................... 3

1.4 Historical Data Review................................................................................................... 3

2.0. Methods............................................................................................................................... 6

2.1 Study Approach .............................................................................................................. 6

2.2 Field Study...................................................................................................................... 6

3.0. Results................................................................................................................................. 7

3.1 Deployment History........................................................................................................ 7

3.2 Continuous EDS Sonde Data .......................................................................................... 8

3.3 Short-term Deployments............................................................................................... 11

4.0. Discussion......................................................................................................................... 18

5.0. Conclusions and Recommendations ................................................................................. 26

6.0. References......................................................................................................................... 28

Figures Figure 1. Sammamish River study area, King County routine ambient monitoring

locations (open circles) and continuous sonde deployment locations occupied during this study (closed circles). ......................................................................................... 2

Figure 2. Sammamish River diel DO and pH data collected in 2000. .............................................. 4

Figure 3. Sammamish River diel DO and pH data collected in 2002. .............................................. 5

Figure 4. Sammamish River sonde deployment history, 2003. ......................................................... 7

Figure 5. Sammamish River YSI EDS raw data, 2003. ...................................................................... 9

Figure 6. Comparison of YSI EDS and YSI 6000 sonde DO data collected at the Redmond Rowing Club, early September 2003. .............................................................. 10

Figure 7. Comparison of YSI EDS and YSI 6000 sonde DO data collected at the Redmond Rowing Club, late September 2003.................................................................. 10

Figure 8. Sammamish River YSI EDS unqualified data, 2003........................................................ 12


King County iii March 2005

Figure 9. Sammamish River YSI unqualified data from the first deployment, 5/29/03 through 6/6/03. ...................................................................................................................... 13

Figure 10. Sammamish River YSI unqualified data from the second deployment, 6/24/03 through 7/2/03. ...................................................................................................................... 14

Figure 11. Sammamish River YSI unqualified data from the third deployment, 7/22/03 through 7/30/03..................................................................................................................... 15

Figure 12. Sammamish River YSI unqualified data from the fourth deployment, 8/22/03 through 9/2/03. ...................................................................................................................... 16

Figure 13. Sammamish River YSI unqualified data from the fifth deployment, 9/25/03 through 10/3/03..................................................................................................................... 17

Figure 14. Longitudinal profiles of Sammamish River maximum temperature, temperature range, minimum DO, and DO range for selected days in 2003...................................... 19

Figure 15. Longitudinal profiles of Sammamish River maximum pH, pH range, minimum DO percent saturation, and DO percent saturation range for selected days in 2003. ....................................................................................................................................... 20

Figure 16. Comparison of 2003 Sammamish River YSI continuous temperature, DO and pH data to water quality standards. .................................................................................... 21

Figure 17. Daily maximum discharge and total daily precipitation recorded by local King County gauges in the Little Bear and Big Bear Creek basins during the study. .......... 23

Figure 18. Temperature, specific conductance, DO and pH data recorded by the YSI EDS sondes, 9/1/2003 through 9/14/2003. ................................................................................. 24

Figure 19. Longitudinal trend in specific conductance, 8/22/2003 through 9/2/2003. .................. 25

Tables Table 1. Continuous YSI deployment locations, 2003 ................................................................8


King County iv March 2005

EXECUTIVE SUMMARY The Sammamish River has recently been the focus of a number of water quality studies, primarily due to the use of the river by Endangered Species Act (ESA) listed species of salmon. A review of Sammamish River monitoring data has also lead the Washington State Department of Ecology to identify water quality problems related to elevated levels of fecal coliform bacteria, temperature, and pH and reduced levels of dissolved oxygen in the river [Washington State Department of Ecology 2000 303(d) list of impaired waters]. King County Department of Natural Resources and Parks (King County) is also currently developing hydrodynamic and water quality models of the river as part of the Sammamish-Washington Analysis and Modeling Program (SWAMP). One goal of this modeling effort is the simulation of diel temperature, dissolved oxygen (DO), and pH dynamics in the river.

Although continuous (15 minute to hourly interval) monitoring of temperature has been conducted at a number of locations along the river and at major tributary mouths since 1998, the current routine sampling program for DO and pH provides only monthly grab sample data. In order to evaluate dynamic model-predictions of DO and pH, more frequent sampling is likely needed. Exploratory data collection conducted during mid- to late summer in 2000 and 2002 indicates that relatively large diel fluctuations of DO and pH occur in the upper river. It is suspected that these fluctuations are driven in large part by the photosynthesis and respiration of dense beds of submerged aquatic plants and attached algae that occupy much of the river channel during summer. Therefore, data on the diel variation of DO and pH are needed to evaluate the significant processes that affect DO and pH levels and make quantitative comparisons between the model and field observations.

In addition to support of water quality modeling, the diel data also provide information that is more suitable than the current monthly grab samples for the evaluation of river water quality with respect to DO and pH.

This report provides a brief description of the field study sampling design and presents the study results. Implications of the monitoring results are discussed and recommendations are also made for future study of the Sammamish River and for continuous DO and pH studies in other King County river and stream systems.

Yellow Springs Instruments (YSI) 6600 series sondes were successfully deployed to collect up to seven days of reliable continuous data on temperature, specific conductance, DO and pH during the summer of 2003. YSI Extended Deployment System (EDS) 6600 sondes were also successfully deployed for up to 30 days in the Sammamish River during the same period. The collected data confirm the significant summer diel variation in DO and pH observed in the initial reconnaissance studies conducted in 2000 and 2002. These fluctuations are most likely due to production and respiration of submerged plants and attached algae that are found throughout the river during summer. One of the goals for development of a water quality model of the Sammamish River is to include the influence of aquatic plants on DO and pH. The data collected provide information needed to develop and test the water quality model.


King County v March 2005

The study also confirmed previous findings that river temperature and DO concentrations in the river often exceed state standard limits that suggest uses of the river by aquatic life (particularly salmon and trout migration and rearing) are impaired. To some extent this is an unavoidable consequence of the inflow of warm lake surface water at the upstream end of the river. However, significant alteration of the river channel and adjacent wetlands and loss of riparian cover along the river and in tributary streams has undoubtedly affected the nature and extent of thermal refugia (Tetra Tech 2002) and possibly created conditions more suitable for aquatic plant growth.

Although not the intended focus of the study, a number of other interesting phenomena were apparent from the data collected. A general increasing trend in specific conductance from upstream to downstream during the summer study period indicates inputs of water with relatively higher conductance along the study reach relative to the upstream inflow from Lake Sammamish. Tributaries and groundwater inputs are the most likely sources of water with higher conductance than the upstream lake inflow. Daily and more frequent oscillations in specific conductance were observed in Big Bear Creek near the mouth. These oscillations suggest a time varying source of either high or low conductance water to the river. Further investigation is required to identify the cause of these fluctuations.

The following specific recommendations are made:

• This type of data collection should be considered for other streams in which water quality impairment due to aquatic plants or attached algae is suspected.

• A synoptic temperature/conductance study focusing on identifying significant surface and groundwater inputs to the Sammamish River should be conducted.

• The cause of the oscillation in specific conductance in Big Bear Creek should be investigated.

• Continuous and/or synoptic temperature and specific conductance monitoring should be considered for other streams in which surface water/groundwater interactions are of interest.

• A study should be conducted to evaluate the distribution and biomass of aquatic plants and benthic algae in the Sammamish River to support the water quality model development.

• A time-of-travel study should be conducted of the Sammamish River during low flow to support water quality model development.


King County 1 March 2005

1.0. INTRODUCTION The Sammamish River has recently been the focus of a number of water quality studies, primarily due to the use of the river by Endangered Species Act (ESA) listed species of salmon. A review of Sammamish River monitoring data has also lead the Washington State Department of Ecology to identify water quality problems related to elevated levels of fecal coliform bacteria, temperature, and pH and reduced levels of dissolved oxygen in the river [Washington State Department of Ecology 2000 303(d) list of impaired waters]. King County Department of Natural Resources and Parks (King County) is also currently developing hydrodynamic and water quality models of the river as part of the Sammamish-Washington Analysis and Modeling Program (SWAMP). One goal of this modeling effort is the simulation of diel temperature, dissolved oxygen (DO), and pH dynamics in the river.

Although continuous (15 minute to hourly interval) monitoring of temperature has been conducted at a number of locations along the river and at major tributary mouths since 1998 (King County, unpublished data), the current routine sampling program for DO and pH provides only monthly grab sample data. In order to evaluate dynamic model-predictions of DO and pH, more frequent sampling is likely needed. Exploratory data collection conducted during mid- to late summer in 2000 and 2002 indicates that relatively large diel fluctuations of DO and pH occur in the upper river. It is suspected that these fluctuations are driven in large part by the photosynthesis and respiration of dense beds of submerged aquatic plants and attached algae that occupy much of the river channel during summer. Therefore, data on the diel variation of DO and pH are needed to evaluate the significant processes that affect DO and pH levels and make quantitative comparisons between the model and field observations.

In addition to support of water quality modeling, the diel data should provide information that is more suitable than the current monthly grab samples for the evaluation of river water quality with respect to DO and pH.

This report provides a brief description of the field study sampling design and presents the study results. Implications of the monitoring results are discussed and recommendations are also made for future study of the Sammamish River and for continuous DO and pH studies in other King County river and stream systems.

In general, continuous sampling for temperature, specific conductance, DO, and pH was conducted at up to eight locations over a 5- to 7-day period in each month from June through the beginning of October 2003. Sampling covered the period of greatest warming, salmonid migration, and time when submerged aquatic plant cover in the river was greatest.

1.1 Study Area The study area included the Sammamish River from the Redmond Rowing Club dock at the outlet of Lake Sammamish to Blyth Park in Bothell (see Figure 1).



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Blyth Park I-405

Woodinville Railroad Bridge

NE 145th Street

NE 116th StreetBig Bear Creek

Redmond Rowing Club

Redmond Railroad Bridge

8000 0 8000 16000 Feet

N

Figure 1. Sammamish River study area, King County routine ambient monitoring locations (open circles) and continuous sonde deployment locations occupied during this study (closed circles).



1.2 Project Background A 2-dimensional water quality model (CE-QUAL-W2) of the Sammamish River is currently under development by King County. The water quality model allows for multiple state variables for phytoplankton that can be used to represent diatoms, green algae, and cyanobacteria. The current version of the model (version 3.2) also has the capability of simulating the growth and decay of algae attached to the river bottom and the effect of attached algal photosynthesis and respiration on DO, pH, and nutrient dynamics. The addition of model components that simulate the effect of submerged aquatic plants on water quality and hydrodynamics is planned in the next version release (Cole and Wells 2003). Current sampling of DO and pH occurs on a monthly basis. However, exploratory diel sampling of DO and pH in the upper reach of the Sammamish River indicates that significant variation occurs over a 24-hour period. In order to understand and model the underlying processes that result in the observed spatial and temporal variation of DO and pH, field measurements that can resolve the diel variation are needed.

1.3 Goals and Objectives The overall goal of this study is the collection of data that will facilitate the development and calibration of the Sammamish River water-quality model. An additional goal is to provide data for the evaluation of river water quality.

1.4 Historical Data Review A limited number of diel DO and pH data have been collected from the Sammamish River. The first continuous (15-minute) recordings were made for 23 days in 2000 at the Redmond Railroad Bridge below the confluence with Big Bear Creek (Figure 2). Additional diel data were collected during four separate 5-to 7-day periods between August 2 and September 27, 2002 at the Redmond Rowing Club, Redmond Railroad Bridge, NE 116th Street Bridge on the Sammamish River and on Big Bear Creek near the confluence with the Sammamish River (Figure 3).

Presently, King County monitors DO and pH (and a number of other parameters) on a monthly basis at a number of locations along the river (see Figure 1).



pH

8/7/00 00:00 8/21/00 00:00 9/4/00 00:00 9/18/00 00:00

pH

7.07.27.47.67.88.08.2

Dissolved Oxygen Concentration

8/7/00 00:00 8/21/00 00:00 9/4/00 00:00 9/18/00 00:00

DO

(mg/

L)

02468

101214

Redmond Railroad Bridge

Dissolved Oxygen Saturation

8/7/00 00:00 8/21/00 00:00 9/4/00 00:00 9/18/00 00:00

DO

% s

at.

020406080

100120140

Figure 2. Sammamish River diel DO and pH data collected in 2000.

DO sensor failure



Redmond Rowing ClubRedmond Railroad Bridge116th Avenue BridgeBig Bear Creek near Mouth


8/5/02 00:00 8/19/02 00:00 9/2/02 00:00 9/16/02 00:00

DO

% s

at.

020406080

100120140


8/5/02 00:00 8/19/02 00:00 9/2/02 00:00 9/16/02 00:00

DO

(mg/

L)

02468

101214

pH

8/5/02 00:00 8/19/02 00:00 9/2/02 00:00 9/16/02 00:00

pH

6.5

7.0

7.5

8.0

8.5

9.0

YSI DO sensor at 116th failed

YSI DO sensor at 116th failed

Noted drift of pH probe at Redmond Rowing Club

Deployment at:Redmond Rowing Club

Deployment at:Redmond Rowing Club116th Ave Bridge

Deployment at:Redmond Rowing ClubRedmond Railroad Bridge

Deployment at:Redmond Rowing ClubBig Bear Creek near mouthRedmond Railroad Bridge

Figure 3. Sammamish River diel DO and pH data collected in 2002.



2.0. METHODS

2.1 Study Approach The study was designed to provide adequate spatial and temporal resolution of DO and pH along the river within the limitations of the available resources. Stations at 7 locations along the Sammamish River (including the upstream boundary) were proposed to provide longitudinal resolution of DO and pH variation. A station on Big Bear Creek near the mouth was proposed to evaluate the influence of tributary DO and pH fluctuations on the Sammamish River. Therefore, the plan was to monitor 8 stations during this study. Proposed station locations are shown in Figure 4. An instantaneous 15-minute sampling interval was used to capture the diel temporal variation of temperature, DO, and pH.

The field study is briefly summarized below. The interested reader is referred to the Sampling and Analysis Project Plan (SAPP) for further details (King County 2003).

2.2 Field Study Diel sampling began in June when the river begins to warm and ended in October when the Chinook salmon migration is nearly complete. Sampling was conducted simultaneously at as many of these stations as was feasible for a period of up to 7 days (Monday-Monday or Friday-Friday) in each month. Sampling instrumentation consisted of calibrated Yellow Springs Instruments (YSI) 6600 and 6600 Extended Deployment System (EDS) sondes capable of relatively long-term autonomous deployment and equipped with temperature, DO, pH, and conductivity probes. Computers and sondes used in the project were set to record in Pacific Standard Time (PST).

Sondes were attached to shore by a stainless steel cable and anchored near the center of the channel using a small weight. The sonde probes were suspended above the bottom by attaching a small float to the sonde’s probe guard. The sondes underwent pre- and post-calibration checks according to the current King County Environmental Laboratory (KCEL) Standard Operating Procedures (SOP) for these instruments (KCEL 2002).

Three YSI 6600 EDS sondes were used to continuously monitor temperature, DO and pH at 3 locations along the river (see Figure 1). These locations were: (1) the upstream boundary at the Redmond Rowing Club; (2) below the confluence with Big Bear Creek at the Redmond Railroad Bridge; and (3) just above the confluence with Little Bear Creek at the Woodinville Railroad Bridge. Depending on availability, an additional five YSI 6600 sondes were deployed for one week each month in June through October at 5 locations (see Figure 1). These locations included Big Bear Creek, NE 116th Bridge, NE 145th Bridge, I-405 overpass and the railroad/pedestrian bridge near Blyth Park. Although stratified conditions have been observed in the Sammamish River below North Creek (DeGasperi 2001), only 1 sonde was available for deployment near Blyth Park to monitor near bottom fluctuations in temperature, DO, and pH.



3.0. RESULTS

3.1 Deployment History Although the performance of individual probes varied, five synoptic week long deployments were made at up to 8 locations during 2003 (Table1, Figure 4). Continuous data collection using the EDS sondes did not begin until late June, but data were collected nearly continuously during the study thereafter except for short periods (up to 4 days) required for sonde maintenance and redeployment. Due to the limited number of working sondes that were available, fewer deployments were made at the NE 145th St. Bridge and Blyth Park locations.

Sammamish River 2003 YSI Sonde Deployment History

Jun Jul Aug Sep Oct

BLYTH

I-405

WRB

145th

116th

RRB

BBC

RRC

RRC = Redmond Rowing ClubBBC = Big Bear CreekRRB = Redmond Railroad Bridge116th = NE 116th St Bridge

145th = NE 145th St BridgeWRB = Woodinville Railroad BridgeI-405 = I-405 BridgeBLYTH = Blyth Park Railroad Bridge

Figure 4. Sammamish River sonde deployment history, 2003.



Table 1. Continuous YSI deployment locations, 2003

Station ID Location Northing Easting Notes

RRC Redmond Rowing Club

241464 1325158 Suspended from club dock

BBC Big Bear Creek 246213 1322758 Upstream of mouth

RRC Redmond Railroad Bridge

248968 1320305 Tethered on left bank

NE116th NE 116th St Bridge 259586 1317941 USGS gaging station

NE 145th NE 145th St Bridge 270120 1317494 Tethered on right bank downstream of bridge

WRB Woodinville Railroad Bridge

278120 1311987 Tethered on right bank in pool upstream of Little Bear Creek

I405 I-405 Bridges 278963 1307984 Between center spans tethered on left bank

Blyth_1 Blyth Park Railroad Bridge (pedestrian)

276814 1301750 Suspended off bottom from left bank bridge pilings

Northing/Easting are in State Plane feet, Washington North, NAD83/91 (HPGN)

3.2 Continuous EDS Sonde Data The raw (unqualified) temperature, specific conductance, dissolved oxygen, and pH data from the continuous EDS sondes placed at the Redmond Rowing Club, Redmond Railroad Bridge, and the Woodinville Railroad Bridge are shown in Figure 5. A number of problems occurred during the initial deployment at the end of May, which was mostly resolved before the sondes were redeployed in late June. However, curious morning spikes in DO were noted in the data reported by the sonde placed at the Redmond Rowing Club before it failed. The sonde underwent additional maintenance and initially performed well until about the end of July when the morning spikes in DO again appeared (see Figure 5). To verify that the DO spikes were artificial, a second sonde was placed next to the EDS sonde and the data were compared (Figure 6). The comparison shown in Figure 6 indicates that the spikes are artificial and should be ignored. The comparison also suggests some spatial or sonde-related variation in measured DO, although a later paired deployment indicated smaller differences between the EDS and 6600 sondes (Figure 7).



Temperature

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

o C

121416182022242628

Redmond Rowing ClubRedmond Railroad BridgeWoodinville Railroad Bridge

Specific Conductance

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

µS/c

m

80

100

120

140

160


5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

mg/

L

02468

1012141618

Dissolved Oxygen Percent Saturation

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

%

020406080

100120140160180200

pH

Date/Time

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

pH

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

DO probe failure and spikes at RRC

Spikes due to redeploymentand calibration checks

DO probe failure and spikes at RRC

Figure 5. Sammamish River YSI EDS raw data, 2003.




8/25/03 0:00 8/29/03 0:00 9/2/03 0:00 9/6/03 0:00 9/10/03 0:00

mg/

L

5

7

9

11

13

15

Redmond Rowing Club (Homer)Redmond Rowing Club (Poirot)

DO Charge

8/25/03 0:00 8/29/03 0:00 9/2/03 0:00 9/6/03 0:00 9/10/03 0:00

#

30

35

40

45

50

55

60

Placed second sonde (Poirot) at same Redmond Rowing Club location (Homer) on 9/2/2003

Figure 6. Comparison of YSI EDS and YSI 6000 sonde DO data collected at the Redmond Rowing Club, early September 2003.


9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

mg/

L

7

8

9

10

11

12

Redmond Rowing Club (EDS-Homer)Redmond Rowing Club (6600-Monica)

DO Charge

9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

#

30

35

40

45

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55

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Placed second sonde (Monica) at same Redmond Rowing Club location (Homer) on 9/22/2003

Figure 7. Comparison of YSI EDS and YSI 6000 sonde DO data collected at the Redmond Rowing Club, late September 2003.



Post-calibration data sheets and additional quality control data recorded by the instruments (e.g., DO charge and battery voltage) were used to qualify bad or unusable data (“R”) and identify unqualified data suitable for use in the water quality modeling effort. The artificial DO spiking of the EDS sonde used at the Redmond Rowing Club presented an unusual problem – the DO probe typically passed post-calibration checks. Therefore, the raw data were reviewed for consistencies in the spiking pattern. Spikes tended to begin between 8:15 and 9:15 AM and return to baseline before noon. Therefore, these data were qualified on the days large DO spikes were observed using “R_SP” for spike. Due to the spiking problem and the relatively poor agreement in the side-by-side sonde DO comparison, the unqualified Redmond Rowing Club data should be used with caution. The unqualified data for all EDS sondes are presented in Figure 8.

3.3 Short-term Deployments Data from the week-long deployments were reviewed and qualified in the same manner as the long-term EDS deployments, resulting in the qualification of some data as unusable (“R”). The unqualified temperature, specific conductance, DO, and pH data collected during each deployment are presented in Figure 9 through Figure.



Temperature

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

o C

121416182022242628



5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

µS/c

m

80

100

120

140

160


5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

mg/

L

2468

10121416


5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

%

20406080

100120140160180

pH

Date/Time

5/1/03 0:00 6/1/03 0:00 7/1/03 0:00 8/1/03 0:00 9/1/03 0:00 10/1/03 0:00 11/1/03 0:00

pH

6.5

7.0

7.5

8.0

8.5

9.0

9.5

Figure 8. Sammamish River YSI EDS unqualified data, 2003.



Temperature

5/29/03 0:00 5/31/03 0:00 6/2/03 0:00 6/4/03 0:00 6/6/03 0:00

o C

12

14

16

18

20

22

NE 116thI-405 Big Bear Creek


5/29/03 0:00 5/31/03 0:00 6/2/03 0:00 6/4/03 0:00 6/6/03 0:00

µS/c

m

8090

100110120130140150160


5/29/03 0:00 5/31/03 0:00 6/2/03 0:00 6/4/03 0:00 6/6/03 0:00

mg/

L

6

8

10

12

14

16


5/29/03 0:00 5/31/03 0:00 6/2/03 0:00 6/4/03 0:00 6/6/03 0:00

%

60

80

100

120

140

160

180

pH

5/29/03 0:00 5/31/03 0:00 6/2/03 0:00 6/4/03 0:00 6/6/03 0:006.8

7.2

7.6

8.0

8.4

8.8

Figure 9. Sammamish River YSI unqualified data from the first deployment, 5/29/03 through 6/6/03.



Temperature

6/24/03 0:00 6/26/03 0:00 6/28/03 0:00 6/30/03 0:00 7/2/03 0:00

o C

12

14

16

18

20

22

24

NE 116thI-405 Big Bear Creek


6/24/03 0:00 6/26/03 0:00 6/28/03 0:00 6/30/03 0:00 7/2/03 0:00

µS/c

m

130135140145150155160165

Dissolved Oxygen Concentration6/24/03 0:00 6/26/03 0:00 6/28/03 0:00 6/30/03 0:00 7/2/03 0:00

mg/

L

4

6

8

10

12

14


6/24/03 0:00 6/26/03 0:00 6/28/03 0:00 6/30/03 0:00 7/2/03 0:00

%

60

80

100

120

140

160

pH

6/24/03 0:00 6/26/03 0:00 6/28/03 0:00 6/30/03 0:00 7/2/03 0:006.8

7.2

7.6

8.0

8.4

8.8

9.2

Figure 10. Sammamish River YSI unqualified data from the second deployment, 6/24/03 through 7/2/03.



Temperature

7/22/03 0:00 7/24/03 0:00 7/26/03 0:00 7/28/03 0:00 7/30/03 0:00

o C

16

18

20

22

24

26

NE 116thNE 145thI-405 Blyth ParkBig Bear Creek


7/22/03 0:00 7/24/03 0:00 7/26/03 0:00 7/28/03 0:00 7/30/03 0:00

/cm

120

130

140

150

160

170


7/22/03 0:00 7/24/03 0:00 7/26/03 0:00 7/28/03 0:00 7/30/03 0:00

mg/

L

56789

10111213

Dissolved Oxygen Saturation7/22/03 0:00 7/24/03 0:00 7/26/03 0:00 7/28/03 0:00 7/30/03 0:00

%

40

60

80

100

120

140

160

pH

7/22/03 0:00 7/24/03 0:00 7/26/03 0:00 7/28/03 0:00 7/30/03 0:006.4

6.8

7.2

7.6

8.0

8.4

8.8

Figure 11. Sammamish River YSI unqualified data from the third deployment, 7/22/03 through 7/30/03.



Temperature

8/22/03 0:00 8/24/03 0:00 8/26/03 0:00 8/28/03 0:00 8/30/03 0:00 9/1/03 0:00 9/3/03 0:00

o C

12

14

16

18

20

22

24

NE 116thNE 145thI-405 Blyth ParkBig Bear Creek


8/22/03 0:00 8/24/03 0:00 8/26/03 0:00 8/28/03 0:00 8/30/03 0:00 9/1/03 0:00 9/3/03 0:00

µS/c

m

110120130140150160170180190


8/22/03 0:00 8/24/03 0:00 8/26/03 0:00 8/28/03 0:00 8/30/03 0:00 9/1/03 0:00 9/3/03 0:00

mg/

L

6789

1011121314

Dissolved Oxygen Saturation8/22/03 0:00 8/24/03 0:00 8/26/03 0:00 8/28/03 0:00 8/30/03 0:00 9/1/03 0:00 9/3/03 0:00

%

60

80

100

120

140

160

pH

8/22/03 0:00 8/24/03 0:00 8/26/03 0:00 8/28/03 0:00 8/30/03 0:00 9/1/03 0:00 9/3/03 0:006.8

7.2

7.6

8.0

8.4

8.8

9.2

Figure 12. Sammamish River YSI unqualified data from the fourth deployment, 8/22/03 through 9/2/03.



Temperature

9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

o C

1213141516171819

NE 116thNE 145thBig Bear Creek


9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

µS/c

m

124126128130132134136138140142


9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

mg/

L

56789

10111213

Dissolved Oxygen Saturation9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:00

%

40

60

80

100

120

140

pH

9/25/03 0:00 9/27/03 0:00 9/29/03 0:00 10/1/03 0:00 10/3/03 0:006.8

7.2

7.6

8.0

8.4

Figure 13. Sammamish River YSI unqualified data from the fifth deployment, 9/25/03 through 10/3/03.



4.0. DISCUSSION In general, it appears that long-term (weekly to monthly) continuous monitoring of DO and pH is feasible. However, the amount of testing and initial maintenance required to bring the available sondes into reliable use was not anticipated. Therefore, the number of stations monitored and the amount of usable data gathered increased over the study period. A large vessel of aerated water capable of holding several sondes was found to be very useful for testing and trouble-shooting the sondes. This vessel is typically used by the King County laboratory to calibrate the SeaBird water quality monitoring instrument. However, some problems were not discovered until the sondes were deployed. Many of the initial problems were resolved after malfunctioning probes were identified and replaced.

Dense beds of aquatic plants and attached algae were observed during the study at Redmond Rowing Club, Redmond Railroad Bridge, NE 116th Street, NE 145th Street and I-405 sampling locations. Due to the depth and/or turbidity of the water at the Blyth Park and Woodinville Railroad Bridge locations, dense beds of aquatic plants were not observed. Submerged vascular plants were not observed at the Big Bear Creek location and the growth of attached algae on the rocky stream bottom was not strikingly heavy. A quantitative survey of aquatic vegetation and/or benthic algae would provide additional support for the development of the Sammamish River water quality model.

Plots of the longitudinal variation of maximum temperature, temperature range, minimum DO, and DO range for five selected days during the 2003 study indicate that temperatures peak throughout the river in late July and that maximum temperatures tend to decrease in the downstream direction (Figure 14). The diel temperature range also tends to be highest in late July and is greatest during this time at the Redmond Railroad Bridge and NE 116th Street locations (Figure 14). DO concentrations reach their minimum levels and DO concentration ranges are at their maximum at these same two locations (Figure 14). Longitudinal profiles of pH maximum, pH range, DO percent saturation minimum, and DO percent saturation range present similar patterns (Figure 15). These patterns are consistent with the observed aquatic plant coverage and longitudinal changes in water depth observed during the study. The locations of greatest maximum temperature and temperature range, lowest DO and largest DO range, and greatest pH and pH range (Redmond Railroad Bridge and NE 116th Street) happen to be in relatively slow moving and shallow reaches of the river. Under these conditions, the dense beds of aquatic plants have the greatest influence on water column carbon and oxygen dynamics. The development of a water quality model of the Sammamish River will provide the means to verify the connection between aquatic plants and DO-pH dynamics and evaluate management approaches that might improve the temperature, DO and pH conditions in the river.

The data collected in 2003 also confirm previous 1998 303(d) listing of the Sammamish River by Ecology for water quality concerns associated with temperature, DO, and pH (Figure 16). Daily maximum temperatures were routinely above the current 18oC standard for Class A freshwaters between June and mid-September throughout the river and daily maximum temperatures



Maximum Temperature

River Mile above confluence with Lake Washington

0 2 4 6 8 10 12 14

o C

1618202224262830

May 31June 27July 26August 25October 1

Temperature Range


0 2 4 6 8 10 12 14

o C

0

1

2

3

4

5

Minimum Dissolved Oxygen


0 2 4 6 8 10 12 14

mg/

L

56789

101112131415

Dissolved Oxygen Range


0 2 4 6 8 10 12 14

mg/

L

0123456789

10

Figure 14. Longitudinal profiles of Sammamish River maximum temperature, temperature range, minimum DO, and DO range for selected days in 2003.



Maximum pH


0 2 4 6 8 10 12 145

6

7

8

9

10

May 31June 27July 26August 25October 1

pH Range


0 2 4 6 8 10 12 140

1

2

Minimum Dissolved Oxygen Saturation


0 2 4 6 8 10 12 14

%

60

80

100

120

140

Dissolved Oxygen Saturation Range


0 2 4 6 8 10 12 14

mg/

L

020406080

100120140

Figure 15. Longitudinal profiles of Sammamish River maximum pH, pH range, minimum DO percent saturation, and DO percent saturation range for selected days in 2003.



7-Day Moving Average of Daily Maximum Temperature

May Jun Jul Aug Sep Oct Nov

o C

14

16

18

20

22

24

26

28

RRCBBCRRBNE116thNE145th WRBI405BLYTHWQS

Daily Minimum Dissolved Oxygen Concentration


mg/

L

2

4

6

8

10

12

14

Daily Minimum and Maximum pH

2003

May Jun Jul Aug Sep Oct Nov 6

7

8

9

10

Figure 16. Comparison of 2003 Sammamish River YSI continuous temperature, DO and pH data to water quality standards.



remained above 18oC through mid-October at the Redmond Rowing Club station located in the Lake Sammamish outlet to the Sammamish River. Daily minimum DO concentrations were below the Class A Standard of 8 mg/L at one time or another at all stations, although concentrations below 8 mg/L were less frequent at the Big Bear Creek and Woodinville Railroad Bridge locations. Excursions of pH above the water quality standard upper limit of 8.5 occurred at a more limited number of stations – primarily Redmond Rowing Club, Big Bear Creek, and the Redmond Railroad Bridge locations in the upper portion of the river basin.

The lowest DO (3.77 mg/L) and pH (6.73) were measured on September 9, 2003 at the Woodinville Railroad Bridge location following the first significant rainfall after an extended dry period (Figure 17). Unfortunately, this rain event occurred between the fourth and fifth sonde deployment so it was only recorded by the three long-term EDS sondes along the Sammamish River mainstem (Figure 18). Rainfall during this event was scattered and variable as evidenced by the difference in response between the rainfall and flow gauges on Little Bear and Big Bear Creeks (see Figure 17). A relatively small rainfall event (0.2 in) and peak flow response was recorded on September 7, 2003 on Little Bear Creek, while 0.8 inches of precipitation were recorded on September 8, 2003 at the Marymoor Park station near the mouth of Big Bear Creek. Big Bear Creek flow responded with an increase in daily maximum flow from 12 to 24 cfs between September 7 and 8. The rain event on September 8, 2003 is recorded as an initial increase and then decrease in specific conductance at the Redmond Railroad Bridge station, presumably due to changes in specific conductance of Big Bear Creek since no change was observed at the Redmond Rowing Club location during the event. The specific conductance at Woodville Railroad Bridge decreased to a minimum value about one day later. Interestingly, larger precipitation events after September 8, 2003 (see Figure 17) did not have as significant of an effect on DO, pH and specific conductance as this particular event, suggesting a “first-flush” type of response to the first late summer/early fall rain event.

Although continuous specific conductance monitoring was not the focus of this study, interesting patterns in the specific conductance data1 other than the storm response noted above can be highlighted. For example, a consistent increase in specific conductance from the most upstream location at the Lake Sammamish outlet to the most downstream Blyth Park location below Little Bear and North Creek inflows is apparent (for examples see Figure 8 and Figure 12). Longitudinal box plots from the fourth deployment between August 22 and September 2, 2003 illustrate this pattern with a few caveats (Figure 19). The lowest conductance was measured in the outlet of Lake Sammamish. The increase in conductance at the Redmond Railroad Bridge is largely due to the input of higher conductance water from Big Bear Creek. Conductance measured at NE 116th St Bridge indicates a further increase that is likely due to higher conductance stream or groundwater inflow. An interesting decrease is noted between the NE 116th and NE 145th St. Bridge locations, suggesting input of lower conductance water along this reach.

1 Specific conductance is a surrogate measure of the concentration dissolved cations and anions in the monitored waters. Due to the relatively conservative nature of these dissolved ions, specific conductance can be used to differentiate among various water sources (e.g., relatively high conductance groundwater vs. low conductance rainfall runoff).




Prec

ipita

tion

(in)

0

1

2

3

4

Flow

(cfs

)

1

10

100

1000

Little Bear I&I rainfall gaugeLittle Bear Creek (30a) stream gauge


Prec

ipita

tion

(in)

0

1

2

3

4

Flow

(cfs

)

1

10

100

1000

Marymoor Park I&I rainfall gaugeBig Bear Creek (02a) stream gauge

Sept. 8

Figure 17. Daily maximum discharge and total daily precipitation recorded by local King County gauges in the Little Bear and Big Bear Creek basins during the study.



Temperature

9/1/03 0:00 9/5/03 0:00 9/9/03 0:00 9/13/03 0:00

o C

121416182022242628



9/1/03 0:00 9/5/03 0:00 9/9/03 0:00 9/13/03 0:00

µS/c

m

60

80

100

120

140

160


9/1/03 0:00 9/5/03 0:00 9/9/03 0:00 9/13/03 0:00

mg/

L

2468

10121416


9/1/03 0:00 9/5/03 0:00 9/9/03 0:00 9/13/03 0:00

%

20406080

100120140160180

pH

Date/Time

9/1/03 0:00 9/5/03 0:00 9/9/03 0:00 9/13/03 0:00

pH

6.5

7.0

7.5

8.0

8.5

9.0

9.5

Figure 18. Temperature, specific conductance, DO and pH data recorded by the YSI EDS sondes, 9/1/2003 through 9/14/2003.




0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

µS c

m-1

100

120

140

160

180

200

RRC

BBC

RRB

NE116th

NE145th

WRB

I405

BLYTH

Big BearCreek

Little Bear Creek

NorthCreek

SwampCreek

Figure 19. Longitudinal trend in specific conductance, 8/22/2003 through 9/2/2003.

A larger increase is noted between the NE 145th St and Woodinville Railroad Bridge locations, which indicates a source of high conductance water. The decrease between the Woodinville Railroad Bridge and I-405 locations is most likely due to the input of lower conductance water from Little Bear Creek. Conductance again increases significantly between the I-405 and Blyth Park locations, suggesting input of water with relatively high conductance. More detailed synoptic surveys performed during the summer low flow period could be performed to better identify the sources of high conductance water entering the river between these monitoring locations.

Another interesting pattern in the specific conductance data is the oscillation observed at the Big Bear Creek monitoring location. The best example of this oscillation pattern appears during the third deployment in late July (see Figure 11) in which the maximum conductance typically occurred just before noon each day. The oscillations in specific conductance at the Big Bear Creek location suggest a daily (or more frequent) variation in input of high or low conductance water to the creek. One possible “source” would be variable groundwater input to the stream resulting from variable groundwater pumping from local municipal water supply wells located in the basin. Evapotranspiration of shallow groundwater by riparian vegetation would be another potential influence. Additional investigation would be required to identify the cause of the observed conductance oscillations.



5.0. CONCLUSIONS AND RECOMMENDATIONS

With sufficient initial maintenance and testing, the YSI 6600 series sondes were successfully deployed to collect up to 7 days of reliable continuous data on temperature, specific conductance, DO and pH. With the same attention to maintenance and testing, the YSI EDS 6600 sondes were successfully deployed for up to 30 days in the Sammamish River. The collected data confirm the significant summer diel variation in DO and pH observed in the initial reconnaissance studies conducted in 2000 and 2002. These fluctuations are most likely due to production and respiration of submerged plants and attached algae that are found throughout the river during summer. One of the goals for development of a water quality model of the Sammamish River is to include the influence of aquatic plants on DO and pH. The data collected provide information needed to test aquatic plant portions of the model.

The study also confirmed previous findings that river temperature and DO concentrations in the river often exceed state standard limits that suggest uses of the river by aquatic life (particularly salmon and trout migration and rearing) are impaired. To some extent this is an unavoidable consequence of the inflow of warm lake surface water at the upstream end of the river. However, significant alteration of the river channel and adjacent wetlands and loss of riparian cover along the river and in tributary streams has undoubtedly affected the nature and extent of thermal refugia (Tetra Tech 2002) and possibly created conditions more suitable for aquatic plant growth.

Although not the intended focus of the study, a number of other interesting phenomena were apparent from the data collected. A general increasing trend in specific conductance from upstream to downstream during the summer study period indicates inputs of water with relatively higher conductance than the upstream inflow from Lake Sammamish. Tributaries and groundwater inputs are the most likely sources of water with higher conductance than the upstream lake inflow. Daily and more frequent oscillations in specific conductance were observed at the Big Bear Creek monitoring location. These oscillations suggest a time varying source of either high or low conductance water to the river. Further investigation is required to identify the cause of these fluctuations.

The following specific recommendations are made:

• This type of data collection should be considered for other streams in which water quality impairment due to aquatic plants or attached algae is suspected.

• A synoptic temperature/conductance study focusing on identifying significant surface and groundwater inputs to the Sammamish River should be conducted.

• The cause of the oscillation in specific conductance in Big Bear Creek should be investigated.



• Continuous and/or synoptic temperature and specific conductance monitoring should be considered for other streams in which surface water/groundwater interactions are of interest.

• A study should be conducted to evaluate the distribution and biomass of aquatic plants and benthic algae in the Sammamish River to support the water quality model development.

• A time-of-travel study should be conducted of the Sammamish River during low flow to support water quality model development.



6.0. REFERENCES Buchak, E.M., R. Jain, and G.A. Krallis. 2001. Sammamish River temperature study: 1998 and

1999 CE-QUAL-W2 calibration and management scenarios. February 2001 Addendum. Prepared for Seattle District, Corps of Engineers, Seattle, WA. J.E. Edinger and Associates, Inc., Wayne, PA.

Cole, T.M. and S.A. Wells. 2003. CE-QUAL-W2: A 2-Dimensional, Laterally Averaged Hydrodynamic and Water Quality Model, Version 3.2. Instruction Manual EL-03-1. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, MS.

DeGasperi, C. 7 November 2001. Brief Summary of the August 2001 Temperature Reconnaissance Study of the lower Sammamish River. Draft Technical Memo to Bob Swarner, King County DNRP, Wastewater Treatment Division, Seattle, WA.

King County. 2003. Sammamish-Washington Analysis and Modeling Program: Sammamish River Diurnal Dissolved Oxygen and pH Study Sampling and Analysis Project Plan. King County, Department of Natural Resources and Parks (KCDNRP), Water and Land Division, Seattle, WA.

King County Environmental Laboratory (KCEL). 2002. Standard Operating Procedure for Unattended SI Multiprobe Operation (SP #: 02-01-008-000). Approved 1/23/2002.

Tetra Tech. 2002. Sammamish River Corridor Action Plan. Final Report. Prepared for U.S. Army Corps of Engineers, Seattle District in partnership with King County Department of Natural Resources and Parks, Water and Land Resources Division. Seattle, WA. http://dnr.metrokc.gov/wlr/waterres/streams/sammrivercorridoractionplan.htm

Documents

Sammamish River Diel pH and Dissolved Oxygen Study · Sammamish River Diel pH and Dissolved Oxygen Study King County i March 2005 Acknowledgements The results and analyses presented