(April 12) The cost of monitoring the spread of contamination from Chino Airport has escalated.
This week, the county board of supervisors upped its contract with an environmental services company from $964,100 to $1,695,880 for work relating to an assessment of the extent of the underground pollution at and around the airfield.
San Bernardino-based Tetra Tech, Inc. was given a previous contract for that work, necessitated by known contamination of the water table around the airport, including a perchloroethylene and trichloroethene (PCE/TCE) plume. Subsequently, it was discovered that fifty-one drums of what is believed to have been napalm were buried at Chino Airport decades ago and remained there until they were discovered in 2010, according to documents in the possession of the Sentinel.
Leakage from those drums partially accounts for the pollution of the area’s aquifer, technicians say.
On the afternoon of July 22, 2010, three buried drums were discovered at the airport during trenching for installation of a storm drain pipeline for a new 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, with which the county has an ongoing contract for environmental assessment. 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. Results of those tests indicated that high concentrations of benzene were present in all of the samples. Benzene concentrations ranging from 1,600 milligrams/kilogram (mg/kg) to 6,800 mg/kg were detected in the resinous material in the drums. The benzene concentration in the soil sample was 170 mg/kg. Also detected were toluene, ethylbenzene, xylene, styrene, 1,2,4-trimethylbenzene, and naphthalene. The tan resinous material appeared to be a jellied fuel mixture.
On July 28, 2010, a geophysical survey was conducted in an effort to locate any additional buried drums. During the survey, anomalies were found in several areas to the east and west of the original excavation, and were marked as possible targets for further investigation. Tetra Tech formulated a removal strategy and submitted it to the California Regional Water Quality Control Board office in Riverside on August 9, 2010 and the staff for the board provided same-day verbal approval of that plan. Excavation and removal of the remaining drums was conducted between August 16 and August 25, 2010. A total of 51 drums, several aluminum canisters and pieces of wood were removed from the excavation and placed into six vapor tight closed top roll-off bins. Excavated soil without obvious contamination was stockpiled and additional soil was excavated from beneath the drums, placed in stockpiles and covered. The resulting excavation measured approximately 100 feet from east to west and 20 feet from north to south. The bottom of the excavation varied from 10 to 15 feet below ground surface.
Well prior to these events, on October 17, 2006, the San Bernardino County Board of Supervisors approved a $200,000 contract with Tetra Tech to conduct a ground water assessment of the water table at the Chino Airport and investigate possible sources of contamination from the airport property. On September 11, 2007, the board approved a $200,000 amendment to extend the assessment services, including investigation, characterization, testing and quarterly report preparation required to identify and mitigate soil and water contamination together with preparing bid documents for an additional 24 months. On September 22, 2009, the board approved a $185,000 amendment to extend the assessment services an additional 12 months to continue the same efforts. A third amendment in the amount of $148,000 was approved by the board on February 15, 2011 to continue investigation, characterization, testing report preparation through February 2012 and perform historical research. On December 13, 2011, the board approved a $231,100 amendment to provide continued inspection and testing services and quarterly sampling/reports.
As a result of Tetra Tech’s work to this point, the county has now completed its required work to characterize the extent of the offsite plume and has filed a timely report with the California Regional Water Quality Control Board. The cleanup and abatement order now requires the county to do more work to investigate sources of contamination on the airport property that are contaminating the groundwater.
This week, the board voted to make a fifth amendment to the contract with Tetra Tech, Inc., increasing the total contract amount by $731,780 from $964,100 to $1,695,880 and extending the contract through April 30, 2015 for professional services related to required compliance with the cleanup and abatement order, including historical site assessment, Phase ll environmental site assessments, environmental compliance audits and the ongoing annual monitoring program.
According to James E. Jenkins, the director of the San Bernardino County Department of Airports, “At times, the California Regional Water Quality Control Board staff have expressed some frustration with the time being taken by the county to come into compliance with the orders. Unfortunately, this resulted in the issuance of a notice of violation on March 28, 2012. The informed and competent representation by Tetra Tech was essential to the county being released by the water board in February 2013 from the obligation to submit monthly status reports on the county’s compliance with its clean-up and abatement orders. These efforts resulted in the water board rescinding the notice of violation. Tetra Tech has proven to be a successful advocate and credible representative of the county to the California Regional Water Quality Control Board and this continued representation will be of great value to the county as it works to complete the investigation at the airport property.”
Jenkins said the contamination survey and cleanup effort at Chino Airport has been complicated by the emergence of information, such as that represented by the discovery of the drums of napalm. “At that time, neither the actual extent nor the chemical make-up of the plume was known, and little was known about contamination on the airport property,” Jenkins said. “The work started by Tetra Tech over the last 6 1/2 years has identified the extent of the plume and its chemical make-up and has identified suspected source areas of contamination. The time needed to complete this part of the work was sometimes delayed by off-site access and permitting problems, but also it appears now that the original time estimation was simply too short to complete the work required by the California Water Quality Control Board. In order to maintain compliance with the water board orders, it is now necessary to extend the contract with Tetra Tech to continue the investigation work on the airport property to locate and identify the sources of the contaminants in the plume.”
Tetra Tech will collect water samples from each of the 33 previously installed monitoring wells at and around the airport, test the samples collected; compile and evaluate the data obtained on a quarterly basis; and prepare reports as mandated by the water board.