(December 16)  The county this week upped by $158,000 its existing $675,000 project budget for the ongoing installation of groundwater monitoring wells at the Chino Airport.
On August 5, 2014 the board of supervisors awarded a contract to Yellow Jacket Drilling
Services, LLC  for the installation of thirty-two groundwater monitoring wells to determine the extent of the contamination in the groundwater beneath the Chino Airport and to track the progress of future plume mitigation measures implemented as part of the ongoing groundwater assessment effort.
A host of chemicals and substances used and cavalierly handled in the past have resulted in soil contamination below and around the airfield, located at 7000 Merrill Avenue in Chino.
On October 31, 1990, the Regional Water Quality Board issued Clean-up and Abatement Order No. 90-134 to the county of San Bernardino for suspected contamination of ground water beneath Chino Airport. At that time, it was suspected that the groundwater had been contaminated due to past usage of Perchloroethylene/Trichloroethene.
Perchloroethylene/Trichloroethene were solvents that were commonly used in the aeronautic industry from the 1930s until the 1990s.
The county complied with the order by conducting activities at the Chino Airport to identify all potential sources of contamination, characterizing identified source areas; remediating discovered soil contamination; characterizing ground water contamination; monitoring groundwater contamination; and mitigating identified groundwater contamination within the confines of Chino Airport.
In 2008, the county installed nine monitoring wells on and adjacent to Chino Airport to assist in the vertical characterization of the suspected contamination plume. In 2010, the county installed 10 additional monitoring wells on and adjacent to Chino Airport to assist in the horizontal characterization of the volatile organic chemical- impacted groundwater plume.
The concern about contamination at and around Chino Airport intensified after the July 22, 2010 discovery of the first three of what turned out to be 51 drums of napalm buried at the airport. The drums were found during trenching for installation of a storm drain pipeline for a Southern California Edison facility. The County of San Bernardino Department of Airports was notified and it contacted the county fire department’s hazardous materials division and Tetra Tech, an environmental engineering and consulting firm.  Tetra Tech retained Double Barrel, a commercial hazardous materials emergency responder, to assess the situation.
Additional drums were discovered that day and by sunset on July 22, 2010, eight buried drums had been removed from the excavation. The drums did not have lids and contained soil on top of a tan resinous material. The contents of the drums were field tested using a chemical identification kit and determined to be a non-explosive, flammable, non-corrosive, organic resin-type material.
Soil samples were delivered to Microbac Laboratory in Riverside for analysis. Microlab determined the drums contained high concentrations of benzene together with lesser amounts of  toluene, ethylbenzene, xylene, styrene, 1,2,4-trimethylbenzene, and naphthalene, leading to the conclusion that the tan resinous material was a jellied fuel mixture, most likely napalm. In all, 51 barrels were unearthed.
According to a report/recommendation to the county board of supervisors coauthored by  Carl Alben, the county’s director of architecture and engineering, and James Jenkins, the county’s department of airports director,  the county should lay out another $158,000 “with Yellow Jacket Drilling Services, LLC, increasing the total contract amount from $565,170 to $724,105, for unforeseen conditions that require increasing the depth of the wells and for the installation of additional groundwater monitoring wells as part of the ongoing groundwater assessment required at Chino Airport. The installation of these wells will allow the county to ensure public safety and promote development of a well-planned, balanced and sustainable county by continuing to take steps to ensure a clean and usable water supply for the region.”
According to Alben and Jenkins, “The additional required work resulted from a separate potential source area of groundwater contamination that was not discovered until after the original contract was awarded, when data was received from additional groundwater borings installed at Chino Airport.”
The additional work includes the collection of continuous cores during drilling required to understand the subsurface conditions through which the plume is migrating; an additional 1,305 feet of drilling for the 32 original groundwater monitoring wells for vertical delineation of the volatile organic compounds plume; and the installation of up to three additional groundwater monitoring wells at three additional locations to effectively monitor the plume over time.
The revised project budget of $811,000 is comprised of multiple components, including $12,000 for permit fees, $3,000 for project management, the $724,105 construction cost and a construction contingency of $71,895.