GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 71-3
Presentation Time: 9:00 AM-5:30 PM


MARIETTI, Jenna Marie, Geology, California State Polytechnic University, Pomona, 3801 West Temple Ave., Pomona, CA 91768,

There has been some concern in California with regards to impacts of oil and gas to shallow groundwater resources, especially during the ongoing drought. Towsley Canyon, located in Newhall, California houses a complex system of oil seeps and saline springs with little publicly available water quality data that is up-gradient of the Santa Clarita watershed. This project assesses basic water quality by analyzing samples of discharged water collected from winter 2015 to spring 2016. Laboratory analyses were conducted in the hydrogeology laboratory at Cal Poly Pomona which included elemental salinity and alkalinity. Alkalinity throughout the system is high ranging from 1500-2400 mg/L, and is slightly higher among samples taken from springs. The pH of seep samples ranged from 6.97 to 8.22, while the pH of spring samples was somewhat lower, ranging from 6.07 to 7.76. Average chloride levels in the springs are twice that in the seeps and four times the EPA secondary standard. Bromine levels range from 15 to 25 mg/L versus those of seeps which range from 0.1 to 10 mg/L. High levels of chloride and bromide combined with the presence of oil and natural gas observed during field sampling possibly suggest a deep marine source of salinity and water. Trace metal analyses from select samples will be presented. Offset from faulting in the south of the canyon may explain the marked difference in chemical levels between seeps and associated springs. More data from the area is necessary to determine the possibility of impacts on the Santa Clarita watershed downgradient.