June 11, 2007

CITY OF PASADENA CHALLENGES NASA
CONCLUSIONS ON PERCHLORATE SOURCE

The city of Pasadena has challenged a National Aeronautics and Space Administration (NASA) report that concludes that the source of perchlorate impacting five of the city’s Sunset Reservoir wells is not from the Jet Propulsion Laboratory (JPL) area.

The report was submitted to the Environmental Protection Agency (EPA), the federal agency overseeing NASA’s environmental cleanup. An agreement between the city and NASA was reached after a long negotiation process during which the city of Pasadena claimed NASA was responsible for perchlorate in the city’s Monk Hill wells as well as the Sunset Reservoir wells. Upon completion of negotiations in January 2006, NASA agreed to fund cleanup of the Monk Hill wells and conduct a study of the perchlorate contamination origin of the Sunset Reservoir wells.

“A final determination from the EPA will take some time, so we’re not going to wait,” said Phyllis Currie, general manager of Pasadena Water and Power (PWP). “We have tolerated the loss of some of our most important water resources for far too long.”

PWP recently completed environmental work for its own treatment plant for the five Sunset Reservoir wells; engineering plans are in progress and funding is being secured. The plant is scheduled to be constructed in fall 2008, with operation beginning in January 2009.

During 1997 tests of Monk Hill and Sunset Reservoir wells, PWP detected perchlorate, a common component of solid rocket fuel. In the late 1990s, when the California Department of Health Services began issuing new regulatory standards for perchlorate, PWP shut down four of the five Sunset Reservoir wells, located southeast of JPL, because the perchlorate levels were too high to meet state standards.

Federal law requires NASA to conduct investigations of perchlorate detection in groundwater. NASA’s study claims the source of perchlorate affecting the five Sunset Reservoir wells is of a different origin than perchlorate disposed of by the U.S. Army in the upper Arroyo Seco in the 1940s and 1950s. The report states that results from four analytical tools – groundwater modeling, groundwater geochemistry, groundwater chemical concentrations and perchlorate isotope analysis – support NASA’s conclusion.

The city of Pasadena retained the services of Geoscience Support Services Inc. of Upland, Calif., to review the NASA report and assess the accuracy of the data and the soundness of the scientific and engineering practices used to reach the conclusions. Geoscience Support Services concluded that the NASA report was not entirely correct and would ultimately lead to inaccurate conclusions.

Geoscience Support Service’s findings regarding NASA’s four analytical tools include the following:

• Groundwater Modeling – A predictive pumping scenario was applied in the NASA report when in fact a historical pumping scenario would have resulted
in a more accurate picture of past groundwater movement. By applying a historical pumping scenario, results would show groundwater movement from the JPL area to the Sunset wells.
 
• Groundwater Geochemistry – The NASA report did not adequately characterize the chemical makeup of water imported into the Raymond Basin which recharged the aquifer below the city, including the JPL area. Claims of imported water impacts to ambient groundwater quality were not supported by data.

• Groundwater Chemical Concentrations – NASA claimed that a type of volatile organic compound, carbon tetrachloride, is an ideal tracer that shows how chemicals originating from JPL travel in groundwater. JPL disposed of these chemicals in the area during the 1940s and 1950s. The Sunset wells do not produce groundwater containing carbon tetrachloride; therefore NASA concluded that perchlorate from JPL is not reaching the Sunset wells.However, Geoscience Support Services found that the association of carbon tetrachloride and perchlorate is not supported by data and that the report did not take into account the differences in how these two chemicals migrate in the groundwater.

• Perchlorate Isotope Analysis – The NASA report did not consider the isotopic fingerprint of perchlorate in water that is imported to the city from Metropolitan Water District of Southern California. Also, NASA did not measure the isotopic signature of the perchlorate source material responsible for the JPL contamination. In addition, the isotope method for perchlorate was applied only for distinguishing between natural and man-made perchlorate sources. The NASA report did not take into consideration other factors which make it much more difficult to compare between different man-made sources versus comparing between natural and man-made perchlorate.

As a result of these findings, the city of Pasadena sent a letter to NASA Remedial Project Manager Steve Slaten on June 5 challenging NASA’s conclusion that the perchlorate source impacting the Sunset wells is not from the JPL area. The Geoscience Support Services report and its response to the NASA study were attached to the letter.