Water Quality in the Lower Tuolumne River Watershed,

Transcription

1 Water Quality in the Lower Tuolumne River Watershed, Dominic Walker California State University Stanislaus January 18 th December 15 th 2014 Advisor: Dr. Matthew Cover California State University Stanislaus Biology Department December 15 th 2014

2 2 TABLE OF CONTENTS ACKNOWLEDGEMENTS... 3 PAGE ABSTRACT... 4 INTRODUCTION... 5 METHODS... 7 RESULTS CONCLUSION APPENDIX A: MONITORING PROTOCOLS LITERATURE CITED... 32

3 3 ACKNOWLEDGEMENTS This project was supported by Agriculture and Food Research Initiative Competitive Grant no from the USDA National Institute of Food and Agriculture. A special thanks to: Tuolumne River Trust, Modesto Junior College, California State University Stanislaus and members of the local community that helped in the monitoring of the Tuolumne River.

4 4 ABSTRACT Water quality affects whether rivers can support uses including domestic and agricultural water supply, recreational activities such as swimming, fish consumption, and healthy aquatic ecosystems. Our objectives were to investigate water quality conditions and raise awareness of the lower Tuolumne River watershed within the northern San Joaquin Valley. This project was collaboration among the Tuolumne River Trust, Modesto Junior College, and California State University Stanislaus, and also included members of the local community. Since 2011 we have surveyed water quality (including temperature, turbidity, nitrate, and phosphate) once per month at five locations in the watershed. High river flows occurred in 2011, while recent years have seen much lower flows. Turbidity, nitrate, and phosphate levels were generally below water quality standards in the Tuolumne River, which mainly receives water from snowmelt in the Sierra Nevada. However, Dry Creek, which receives water from urban and agricultural land uses, had higher pollutant levels, including nitrate and phosphate levels above water quality guidelines. Water temperature and conductivity in the main stem Tuolumne River were higher at downstream locations and correlated with urban and agricultural land use. The results of this study can serve as a baseline for future monitoring efforts, which should focus on maintaining water quality standards and the continual care for aquatic life in the lower Tuolumne River.

5 5 INTRODUCTION Why is water quality so important? In a general sense, water is the source of all life. The quality of water is so important because most organisms have a defined environment that must be maintained or those organisms will die. More locally water is an important asset. It helps to support uses including domestic and agricultural water supply, recreational activities such as swimming, fish consumption, and healthy aquatic ecosystems. Water quality in the lower Tuolumne River varies throughout the year. The variance of which is closely related to the seasons. Peaks are generally seen in the summer and during times of harvest. Lower levels are generally seen in the winter. Under the Federal Clean Water Act the State and Regional Water Boards assess water quality data in California every two years. It is here that pollutants are found that exceed water quality criteria and standards. The pollutants are then placed in a list that is categorized by the body of water from which they are found. The pollutants listed in the Final California 2010 Integrated Report (303(d) List/305(b) Report)(All California Regional Water Quality Control Boards) for the Lower Tuolumne River (Don Pedro Reservoir to San Joaquin River) included: metals (As, Cd, Cr, Cu, Pb, Ni), pesticides/herbicides(dacthal, Dimethoate, Malathion), pathogens (Escherichia coli), nutrients/minerals(b, Se, Zinc), and other water quality indicators (NH 3, Cl, Nitrate as Nitrate (NO3), Specific Conductivity, and ph). The Tuolumne River water quality monitoring program began in 2011 as a collaboration of Tuolumne River Trust, California State University Stanislaus, Modesto Junior College, with the goals of 1) collecting data on pollution levels within the lower Tuolumne River, 2) increasing potential involvement and education in the Tuolumne River.

6 6 Due to budget issues we were not able to test all of these pollutants but we were able to test a few that were listed. We tested for Nitrate (mg NO 3 as N/L), Phosphate (mg PO 4 /L), ph, and Conductivity (us/cm). We also tested for other parameters that were not listed by the State and Regional Water Boards. The monitoring events that occurred, took place were once a month, where one of three main facilitators oversaw the event. These main facilitators would then call on local community members and students to come out and help. It is with these monitoring events and data analyses that future students and community members will be educated so that local water supplies will be maintained for future use. We believe that due to decreasing water flow from the La Grange Dam, a negative correlation can be found from that of parameters such as Nitrate (mg NO 3 as N/L), and Phosphate (mg PO 4 /L). It is thought that an increase in these parameters might be directly correlated to an increase in impervious area. The thought being that as water flows further downstream from La Grange Dam; the river collects more runoff from both urban and agricultural areas.

7 7 METHODS STUDY SITES We monitored water quality consistently at five sites in the northern San Joaquin Valley (Fig.1). Four of these sites were on the lower Tuolumne River (upstream to downstream): Waterford, Ceres Riverbluff- Upstream, Ceres Riverbluff- Downstream, and Riverdale Park. One of the sites was Dry Creek, a tributary to the Tuolumne River that flows through agricultural lands and the city of Modesto. Impervious area increased in a downstream direction, and was highest in the Dry Creek watershed (Table 1). SAMPLING METHODS Monitoring was performed once per month from January, 2011 to June, Water samples were collected from m from the bank in flowing water between 9:00 am and 2:00 pm, and analyzed in the field for the following parameters: Temperature (ºC), Turbidity (NTU), Nitrate (mg NO 3 as N/L), Phosphate (mg PO 4 /L), Dissolved Oxygen (mg/l), ph, Conductivity (us/cm). Detailed monitoring protocols and descriptions of each field kit and given in Appendix A: Monitoring Protocols. We also recorded information on, weather conditions, and habitat conditions during each site visit. Generally parameters of water quality conditions were fairly consistent among the 5 sites on the mainstream Tuolumne River (Table 2). Consequently, we chose to present data from only one site on the mainstream, the Tuolumne River at Waterford. We contrast the results from the mainstream with data from Dry Creek, a tributary stream that enters the Tuolumne River at Modesto.

8 8 1 Site Percentage of impervious area Miles from La Grange Dam Longitude latitude Waterford '5.21"W 37 38'10.86" N Ceres Riverbluff- Upstream '41.62"W 37 36'58.08" N Ceres Riverbluff- Downstream '47.88"W 37 36'58.23" N Dry Creek '3.30"W 37 38'38.33" N Riverdale '25.29"W 37 36'46.11" N Table 1. Location and characteristics of study sites. 2 Median Value Site DO ph N P Turbidity Waterford Ceres Up Ceres Down Riverdale Dry Creek Table 2. Water quality in lower Tuolumne River in 2012 (Median Values).

9 9 1 FIG. 1. Locations of the six monitoring stations in the lower Tuolumne River of California, the Tuolumne River flows from east to west, and enters the San Joaquin River near Shiloh Road.

10 10 RESULTS HYDROLOGY: Stream flow for the lower Tuolumne River, owes its flow rates to agricultural and urban runoff, as well as owing the bulk of its rates to the La Grange Dam. The La Grange Dam is in fact the key factor in controlling stream flow in the lower Tuolumne River. Whereas tributaries like Dry Creek owe all discharge to agricultural and urban runoff. By acquiring data from USGS Current Water Data website ( we were able to build a graph showing discharge from below La Grange Dam. As seen (Fig.2) the amount of discharge from 2011 to 2014, has steadily decreased with each passing year. It is understood that with decreased discharge, there is decreased flow and therefore increased pollutant levels FIG. 2. Hydrograph of the Tuolumne River below La Grange Dam. Snowmelt from the Sierra Nevada is captured in Don Pedro Reservoir, and diverted for urban and agricultural uses. Flow in the lower Tuolumne River is highly regulated by dams was a very wet year, with high flow releases from the dams. Subsequent years (2012, 2013, and 2014) have been very dry, with minimal releases

11 11 WATER TEMPERATURE (⁰F): Water temperature is another important water quality parameter because like ph, aquatic life can only inhabit a certain range of water temperature. Water temperature has an effect on the amount of dissolved oxygen in the water; colder water can store more dissolved oxygen whereas warmer water is the opposite and has a more difficult time with storing dissolved oxygen. Water temperature also affects the speed of chemical and biological reactions. It can be affected by the seasons but also by the turbidity of the water. We found that when we collected data during the winter, water temperature was generally cooler and when we collected data during the summer, readings were generally higher (Figs. 3, 4). We found that as we moved from upstream to downstream, water temperature increased overall (Fig. 5). The average water temperature was 61.4 (⁰F) and the range of water temperature was (⁰F) (Figs. 3, 4 and 5). 3 FIG. 3. Water temperature ( F) in Dry Creek from November, 2011 to May, 2014.

12 12 4 FIG. 4. Water temperature ( F) in Waterford from January, 2011 to May, FIG. 5. Average water temperature (⁰F) as the river flows downstream (Waterford, Ceres Riverbluff- Downstream, and Riverdale) from January, 2011 to May, 2014.

13 13 AIR TEMPERATURE (⁰F): Air temperature is very similar to water temperature, in the fact that water temperature is affected by air temperature. Air temperature therefore directly affects water temperature and air temperature can be directly affected by the seasons. In our data collection we found that these statements were pretty sound. We found that when we collected data during the winter air temperature was generally cooler and when we collected data during the summer, readings were generally higher. In our data analysis we saw that the two graphs (Air Temperature ⁰C and Water Temperature ⁰C) within a single site displayed a similar pattern (Figs. 6 and 7).

14 14 6 FIG. 6. Air temperature ( F) in Dry Creek from November, 2011 to May, FIG. 7. Air temperature ( F) in Waterford from January, 2011 and was last monitored May, 2014.

15 15 PH: The ph is measured for water quality in order to indicate the alkalinity or acidity of the water. The ph data that was taken from the five sites ranged from 7 to 10 and had an average ph of 7.93 (Figs. 8 and 9). We found that Waterford had slightly higher ph readings, often ~0.1, than in the rest of the mainstream Tuolumne River which averaged a ph of 8 (Figs. 10 and 11). The highest ph readings in Waterford occurred in April, 2013 (ph 9.97). In general, ph readings tended to peak in April, FIG. 8. ph in Dry Creek from November, 2011 to May, 2014.

16 16 9 FIG. 9. ph in Waterford from January, 2011 to May, 2014.

17 17 CONDUCTIVITY: Conductivity is measured in water quality as a rough indicator on the amount of pollution within a body of water. We found that all five sites varied from month to month. This variance was seen at the Waterford site with the lowest reading being recorded in August, 2011 (20 us/cm) and the highest reading in December, 2012 (90 us/cm) (Fig.11). While all sites showed variance from month to month, the most significant readings were found at the site Dry Creek. Dry Creek is a tributary that flows into the Tuolumne River. The highest reading was recorded in February, 2013 (230 us/cm) and the lowest reading was in March, 2013 (50 us/cm) (Fig. 10). In our studies we believed that conductivity would mainly be affected by runoff from urban and agriculture. Unlike many other parameters, conductivity varied considerably among the mainstream Tuolumne River sampling sites. For example, conductivity levels at Waterford, the upstream site, were 40 us/cm to 90 us/cm (Fig.11). While levels at Riverdale Park, the downstream site, were 40 us/cm to 210 us/cm (Fig.12). The data that was analyzed, along with the data that was made available by SteamStats, suggests that as impervious area increases, conductivity increases (Fig.13).

18 18 10 FIG. 10. Spec. cond. (us/cm) in Dry Creek from November, 2011 to May, FIG. 11. Spec. cond. (us/cm) in Waterford from January, 2011 to May, 2014.

19 19 12 FIG. 12. Spec. cond. (us/cm) in Riverdale from January, 2011 to May, FIG. 13. Spec. cond. (us/cm) vs percentage of impervious area in the lower Tuolumne River, as well as the tributary Dry Creek from January, 2011 to May, 2014.

20 20 DISSOLVED OXYGEN: Dissolved oxygen is important in water quality because it has a direct effect on the aquatic ecosystem. The plants and the atmosphere provide dissolved oxygen but it can be consumed by: bacteria and even industrial and agricultural runoff. Dissolved oxygen data was consistently monitored between the five sites from November, 2011 to April, The sites Ceres Riverbluff- Downstream, Ceres Riverbluff- Upstream, were the most consistent ranging from about 8 to about 10 mg/l O2. Dry creek reached as low as 2.96 mg/l O2 in July, 2012 and 3.71 mg/l O2 in November, 2012 (Fig.14). Riverdale reached slightly higher than 10mg/L which was mg/l O2 recorded on September, Waterford ranged from 7 to about 12mg/L O2 (Fig. 15). 14 FIG. 14. Dissolved oxygen (mg/l) in Dry Creek from November, 2011 to April, 2013.

21 21 15 FIG. 15. Dissolved oxygen (mg/l) in Waterford from January, 2011 to April, ARSENIC: We studied this parameter due to the fact that it can enter the water as natural deposits in the earth or from agricultural and industrial run off. Arsenic was monitored from January, 2011 to September, Arsenic levels were fairly consistent as far as data analysis is concerned. The readings of the monitoring read either 4 or <4. There were only two sites that had readings of 4 ppb which were Riverbluff, Ceres- Upstream taken January, 2011 and Riverbluff, Ceres- Downstream taken February, 2011.

22 22 NITRATE: Nitrate is a necessary nutrient for plant growth, but in excess it can cause cycles of rapid algae and plant growth and decay, a process known as eutrophication. Eutophication can then cause low levels of dissolved oxygen, which is problematic for many forms of aquatic life, including fish. In this study we found that Dry Creek had higher nitrate levels, up to 5 mg/l, than in the mainstream Tuolumne River which was consistently <3 mg/l (Figs. 16 and 17). The highest nitrate levels in Dry Creek occurred in August, 2013 (4.1 mg/l) and June, 2014 (4.9 mg/l). In general, nitrate levels tended to be higher during the spring and summer (April- September) and lower in the winter, with some variation. 16 FIG. 16. Nitrate (ppm) in Dry Creek from September, 2011 to May, 2014.

23 23 17 FIG. 17. Nitrate (ppm) in Waterford from February, 2011 to May, PHOSPHATE: Phosphate is an important nutrient that, in high amounts, can contribute to blooms of algae and aquatic plants, which can reduce oxygen levels. In our studies we found that phosphate levels in the Tuolumne River were consistently <1 mg/l (Fig.19). Phosphate levels however, in the tributary Dry Creek were more variable, ranging from 0 3 mg/l (Fig.18).

24 24 18 FIG. 18. Phosphate (ppm) in Dry Creek from September, 2011 and was last monitored May, FIG. 19. Phosphate (ppm) in Waterford from February, 2011 to May, 2014.

25 25 TURBIDITY: Turbidity (i.e., cloudiness) reduces the amount of light that passes through the water, reducing photosynthesis, the production of oxygen, and feeding effectiveness of many animals. We found that Dry Creek had much higher turbidity, often >10 NTU, than in the mainstream Tuolumne River which was consistently <5 NTU (Figs. 20 and 21). The highest turbidity levels in Dry Creek occurred in May, 2012 (20.8 NTU) and December, 2012 (24.9 NTU). In general, turbidity levels tended to be higher during the spring and summer (April-September) and lower in the winter, with some variation. Turbidity was >5 NTU in the mainstream Tuolumne River on only one occasion (September 2012, 8.86 NTU at Waterford). 20 FIG. 20. Turbidity (NTU) in Dry Creek from September, 2011 to May, 2014.

26 26 21 FIG. 21. Turbidity (NTU) in Waterford from February, 2011 to May, 2014

27 27 CONCLUSION Studies have linked agricultural and domestic runoff to increased water pollutants in river systems (Kibena, 2013; Hongmei Bu, 2014). Furthermore, it has been found that the pollutant levels increase going from upstream to downstream (Kibena, 2013). Our study while noticing these patterns, also found that there was a seasonal link between high and low values. Our particular study was conceived with the idea of continual education. It is by this study that college students and local community members share in hands on monitoring of their local watershed. In this study there was one particular goal in mind which was to acquire baseline data that could help in understanding correlations between drought and seasonal flows of the local water supply. In conclusion we found out that the Phosphate, nitrate and turbidity levels were generally lower in the Tuolumne River compared to that of the tributary, Dry Creek. We also found that the difference in pollutant levels, as seen from data collected is due to two key factors: (1) the Tuolumne River has received less water flow due to decreased snow melt and precipitation, and (2) Dry Creek is a tributary which receives water mostly from urban runoff.

28 28 APPENDIX A: MONITORING PROTOCOLS PO 4 LEVELS: The Hach phosphate test kit (Model #: ) is used to determine phosphate (PO 4 ) levels in water to the nearest 0.01 mg/ml. The process of which was to obtain the two small test beakers that are inside the test kit. Then using the water collected at the site, pour the water into the two test beakers, each of which are marked to 10 ml. Make sure that the meniscus is even with the line on the small test beakers. Inside the test kit are little packets of reagent (PhosVer 3 Phosphate Reagent for 10 ml sample). Pour the reagent into the one of test beakers. Seal the test beaker and shake for 15 minutes. Then let the solution sit for 2 minutes. Afterwards grab the HACH Pocket Colorimeter II, and turn it on by pressing the button that looks like a light bulb. Once the system is on, put the test beaker without reagent (blank) into the test beaker slot, and cover the test beaker. Then press the blue button. Once the Colorimeter is zeroed out switch out the beaker without reagent to the beaker with reagent and press the green check mark button and record the PO 4 (mg/l) level. When done pour beaker with reagent into a waste container. Beaker without reagent does not need to be poured into waste container but does need to be poured out. Take both beakers and pour in some deionized water, seal, shake and pour into waste container. NO 3 -N LEVELS: Using a HACH test kit that generally read to the nearest 0.0, we were able to read levels of nitrate (NO 3 -N) in the water. The process of which was to obtain two small test beakers that are inside the test kit. Then using the water collected at the site, pour it into the two test beakers. Make sure that the meniscus is even with the indicated line of 10 ml on the test beakers. Inside

29 29 the test kit are little packets of reagent (NitraVer 5 Nitrate Reagent for 10 ml sample). Pour the reagent into one of the small test beakers. Seal the test beaker and shake for 15 minutes. Then let the solution sit for 5 minutes. Afterwards grab the HACH Pocket Colorimeter II, and turn it on by pressing the button that looks like a light bulb. Once on put small test beaker without reagent (blank) in test beaker slot, cover test beaker and press the blue button. When the Colorimeter is zeroed out, switch out the test beaker without reagent to the beaker with reagent and press the green check mark button and record the NO 3 -N (mg/l) level. Once done, pour test beaker with reagent into a waste container. Beaker without reagent does not need to be poured into waste container but does need to be poured out. Take both beakers and pour in some deionized water, seal, shake and pour into waste container. WATER TEMPERATURE/PH: Water temperature and ph are recorded by using a waterproof phtestr 30 double junction. The process of which is to take the phtestr30, and press (ON/OFF) once to turn on the phtestr30. Approach the water, stretch out your arm as far as possible and place the probe into the water. Press button (CAL) on the probe which will calculate both Water Temperature and ph. After about a minute press ( ), and the data will be held on the screen so that it will not be lost. Record data and then to turn off the phtestr30, press (ON/OFF) once again. Pour a small amount of deionized water over the probe. Temperature is recorded in ( C) and then converted to ( F) using the equation = (9/5 x C) +32. AIR TEMPERATURE ( C):

30 30 Air Temperature is obtained using a household thermometer. The thermometer is held outside, once stabilized, the air temperature is recorded. Temperature is recorded in ( C) and then converted to ( F) using the equation = (9/5 x C) +32. CONDUCTIVITY (US/CM): The instrument used is ECTestr low 0 to 1990 us/cm, Waterproof, Microprocession Series. The process of recording conductivity is to take the ECTestr, and press (ON/OFF) once to turn the system on. Then getting next to the water that is being tested, stretch your arm out as far as possible and place the probe into the water. The probe will then calculate Conductivity (us/cm). After about a minute press (HOLD), and the data will be held on the screen so that it will not be lost. Record data and then to turn off the system, press (ON/OFF) once again. Pour a small amount of deionized water over the probe. TURBIDITY (NTU): The instrument used for turbidity (NTU) is a LaMotte TC-3000e. In the LaMotte TC- 3000e there are two small beakers. Fill one to the indicated line with deionized water, this will be the blank. Fill the other small beaker to the indicated line with sample water, this will be the sample. Press (ON) button, a selection screen will come up look for Measurements and press (*/OK). Then another selection will appear on the screen look for Turbidity and press (*/OK). The system will then ask you to place the blank into the machine. Once it is placed into the slot, press (*/OK). The system will then ask for the sample to be placed in the small beaker slot. Once

31 31 it is placed into the slot, press (*/OK). Read the data, dispose of the sample and clean with deionized water.

32 32 LITERATURE CITED Bu Hongmei, Meng Wei, Zhang Yuan, and Wan Jun Relationships between land use patterns and water quality in the Taizi River basin, China. Ecological Indicators. 41: Kibena, J., I. Nhapi, and W. Gumindoga Assessing the relationship between water quality parameters and changes in landuse patterns in the Upper Manyame River, Zimbabwe. Physics and Chemistry of the Earth, Parts A/B/C :