Discharge and Geochemical Characteristics of Evey Canyon and Icehouse. Canyon Springs, San Gabriel Mountains, During Extended Drought.

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1 1 Discharge and Geochemical Characteristics of Evey Canyon and Icehouse Canyon Springs, San Gabriel Mountains, During Extended Drought Paula Soto California State Polytechnic University, Pomona Internship Dates: March 4, 2014 to March 3, 2015 Dr. Jonathan Nourse and Dr. Stephen Osborn California State Polytechnic University, Pomona March 4, 2015

2 2 Table of Contents Acknowledgements page 3 Executive Summary...page 4 Project Objectives...page 5 Project Approach...page 6 Project Outcomes pages 7-10 Conclusions.pages 11-13

3 3 Acknowledgements This project was supported by the Hispanic-Serving Institution s Education Program Grant no from the USDA National Institute of Food and Agriculture. A special thanks to the Water Resources Institute at California State University, San Bernardino and the SEES program for funding of this project. Thanks are to Dr. Jonathan Nourse and Dr. Stephen Osborn for advising this thesis project and to the Cal Poly Pomona Geological Sciences Department as well as the University of Arizona for the use of the Hydrology and Water Quality Lab.

4 4 Executive Summary Evey Canyon and Icehouse Canyon (IH Cyn) are major tributaries that feed the San Antonio Creek watershed in the San Gabriel Mountains. An improved understanding of flow rates and water quality is important for water resources management of downstream cities and stakeholders. The following data and results were recorded during years 2 and 3 of an extended drought. Since May 2013, we gauged and sampled two types of springs: 1) direct discharge from the cracks and fractures of fault zones in the quartz diorite bedrock, and 2) drainage from the Cedar Glen landslide in contact with bedrock. Evey Creek discharge varied from gpm; with 2014 base flow values lower than the previous year despite a minor recharge event in December Total dissolved solid concentrations particularly sulfate levels increased systematically downstream from the source springs. These trends suggest increased interaction with the surrounding rock and soil units. In IH Cyn, we sampled four springs for oxygen-hydrogen isotope and tritium analysis to assess the degree mixing of deeper bedrock-sourced groundwater with shallower waters related to landslide discharge. The 18 O and deuterium analyses plot on the local meteoric water line, indicating that the original meteoric source water has not been mixing with anomalous sources. IH Cyn data have more negative values on the meteoric line than Evey Canyon data, consistent with colder, higher elevations of IH Cyn watershed. Results of tritium analyses conclude that the ages of these IH Cyn waters range between 24 to 32 years meaning they tap a deeper, older groundwater source that originated from local precipitation.

5 5 Project Objectives The project was used for research on the watersheds of San Antonio Creek in the San Gabriel Mountains. Little water quality assessment has been done within the area of study and as such, a better understanding will lead to better decisions made concerning water resources management. The results of this would be especially beneficial to the stakeholders who lay claim to the groundwater resources, which include the City of Mt. Baldy, Snow Crest Heights Home owners association, San Antonio Water Corporation (water rights owner), and the U.S. Forestry Service. The watershed also serves the cities of Claremont, Upland, and Montclair. Due to the ever-growing demand for fresh water resources, becoming a hydrologist would serve a greater purpose to the community. Water is important not only for human consumption but also for agricultural use in terms of crop maintenance and other needs. Originally, this project was set out to monitor the changes in the sources of groundwater over a time period of El Niño conditions. However, due to unexpected extended drought conditions, the goal of the project changed to monitoring the effects of an extreme drought on local watershed resources. Flow readings were assessed by using a flow meter and calculating the cross sectional area of the stream at the point taken. Geochemistry samples were also taken from three main geographical points along Evey Canyon Springs and two main geographical points in Ice House Canyon.

6 6 Project Approach Although the goal of the project changed, the methods and means by which we achieved our goals remained unchanged. Water samples taken over the time span from May 2013 till October 2014 were analyzed for alkalinity, anion concentration, cation concentration, and ph levels. The alkalinity was measured in the Cal Poly Pomona geochemistry lab by means of titration using hydrochloric acid with 0.1 normality. The samples were also run through an ion chromatograph to determine the concentration of anions (fluoride, nitrate, sulfate, chloride, and bromide) in the water. Samples were also sent to the University of Arizona s geochemistry lab for cation (iron, aluminum, silica, and) and isotope ( 18 O and deuterium) concentration analysis. The results were then plotted on Excel sheets to show any apparent trend. Flow readings were also taken using a flow meter at the main geographical points: Upper, Mid, and Lower Evey Canyon as well as Ice House Canyon Spring #1 and #2. The cross sectional area of the streams were taken and from there, multiplied by the velocity of the current thus yielding the flow output in volume.

7 7 Project Outcomes Upon analyses of the data, the following results were yielded: Sulfate Anion Concentrations Amount (ppm) Upper Evey Cyn Mid Evey Cyn Lower Evey Cyn 13-Jul 13-Dec 14-Mar 14-Jul 14-Aug This sulfate ion concentration plot shows a reproducible upstream to downstream increase, which is consistent over time. This may record groundwater contributions from fractured meta-sedimentary bedrock sources known to contain oxidized pyrite. Elevated SO4 levels are probably not from gypsum as these rocks are not part of the sedimentary protoliths. There is also an obvious decrease in concentrations during March when there was a minor recharge event at the beginning of the month.

8 8 Amount (ppm) Chlorine Anion Concentrations Jul 13-Dec 14-Mar 14-Jul 14-Aug 0.00 Upper Evey Cyn Mid Evey Cyn Lower Evey Cyn Although chlorine ion concentration levels are significantly lower, the same trend displayed with sulfate concentrations is apparent in chlorine. The lower levels of both sulfate and chlorine in the above figures during March 2014 can be attributed to a large rainstorm event in early March thus resulting in what appears to be a dilution event.

9 9 Mid Evey Canyon Flow Rates June 2013 to August Flow Rate (gpm) May-13 Aug-13 Nov-13 Mar-14 Jun-14 Sep-14 Dec-14 Flow rate data taken over years 2 and 3 of a severe drought show an increase during the wet season, and a drastic base flow recession period between March 2014 and September 2014, interrupted by a rain event in August Base Flow Recession at Mid Evey Canyon lnq (in ft 3 /s) y = x Jan-14 Mar-14 Apr-14 Jun-14 Jul-14 Sep-14 In the above figure, Q was measured in ft 3 /s between March 2014 and September 2014 when this period of base flow recession began. The base flow recession constant is calculated to be

10 10 This chart was originally used in Wicks, 2014; Nourse and Osborn unpublished. Samples were collected on October 9, Two adjacent springs, Cedar Glen Spring and IH Canyon Spring 1, vary considerably in tritium age. This could be due to Cedar glen tapping into deeper, older groundwater and IH Spring 1 mixing with modern rainwater and snow melt. Throughout the entire project, time management was extremely important in terms as to taking measurements at consistent time intervals. The importance of detailed notes with accurate drawings is also crucial to being able to go back and accurately recall certain information and correlate data collected at a specific site.

11 11 Conclusions The results of this experiment have proven to be very interesting. Evey Canyon anion concentrations from the results recorded over the past year have consistently shown a reproducible increasing trend in concentrations from upstream to downstream. As the flow path increases, more interaction between the stream waters and the surrounding geology increases as well. All anion concentration levels ranged from 0 ppm to 8 ppm in previous preliminary results and the results presented here today. However, sulfate concentrations range from 23 ppm to 40 ppm, much higher than other ion concentrations. This may record groundwater contributions from fractured meta- sedimentary bedrock sources in the surrounding area, containing oxidized pyrite. Gypsum is probably not a likely source of contribution since it is not part of the local sedimentary protolith. Low levels of chlorine indicate that the mixing of seawater with these waters is not important. It could also possibly point towards halite not being an important source in chlorine either. Low nitrate levels also indicate relatively clean water in the sense that there was little anthropogenic interaction at the test sites. Lower concentrations of sulfate and chlorine ions during the March 2014 sampling indicate some kind of dilution event due to a rainstorm event in early March. While sulfate levels at all three sites were lower than usual, Upper Evey Canyon chlorine levels remained normal during the sampling date. This can possibly be attributed to a higher abundance of vegetation in the area and therefore the vegetation may be taking up some of the water or intercepting the precipitation. We used chlorine as a reference point for dilution due to its conservative nature. These

12 12 samples were taken a few days after the rainstorm event. Evey Canyon flow rates have changed dramatically. Flow in gpm went from 90 gpm to 18 gpm in about a one year time period. This is consistent with water levels during years 2 and 3 of a severe drought. Icehouse Canyon tritium samples have displayed two possible groundwater sources for the springs in the area. IH Spring #1 is lower in tritium age than the adjacent Cedar Glen Spring. This could possibly be due to IH Spring #1 mixing with modern rainwater and snow melt while Cedar Glen may be tapping into a deeper source of groundwater from fractured bedrock. Questions for further research include: 1) How much groundwater discharge is contributed by the Ice House Canyon fault as opposed to the Cedar Canyon landslide 2) Can the two potential groundwater sources be distinguished with tritium ages 3) How will hydro-chemistry be affected during and after the next heavy precipitation season 4) What is the source of the high sulfate levels found in the Evey Canyon Springs? Beginning the mapping of the area of the springs would also be a next step forward. Upon coming to a conclusion of the geology of the area, those results could then be compared to the geochemical results to make sure they correlate. Upon completion of this internship, this project has enabled for me to experience the duties I would have should I choose to work at an environmental consulting firm. I can now properly collect water samples, monitor water levels,

13 13 asses water quality through geochemical tests, understand the importance of time management and commitment, and know how to run an ion chromatograph. With respect to my prospective career with the USDA, I am now closer to understanding the importance of hydrology and the geochemistry of water in today s society. I am also able to preform the certain duties that may be required of me as a field geologist or hydrologist.