More than fifty 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, documents obtained by the Sentinel show.
While the material represented a potential ecological hazard to the ground and groundwater beneath the airport, the prompt removal of the drums and their contents by county officials alleviated that danger and most or all of the contamination has been remediated, a state water resources official said.
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 TetraTech, an environmental assessment company under contract to the county. TetraTech 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. The eight drums were placed in a roll-off bin. Two more drums were visible in the excavation, but were left in place due to limited remaining daylight. Samples were collected of the soil, the material in the drums, and the liquid in one of the drums. The samples were delivered to Microbac Laboratory in Riverside, and analyzed for volatile organic compounds, semi-yolatile organic compounds, total petroleum hydrocarbons carbon range, polynuclear aromatic hydrocarbons, flashpoint and their content of antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, thallium, vanadium, and zinc. The analytical results 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. TetraTech 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-offbins. 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.
Patricia Hannon, a staff member of the California Regional Water Quality Control Board, observed the collection of the final confirmation soil samples on August 26, 2010. Personnel from the U.S. Environmental Protection Agency and the California Department of Toxic Substances Control were also present. The samples were submitted to a California certified laboratory for analysis. The analytical results for the soil samples showed very low concentrations of benzene, ethylbenzene, xylene, trimethylbenzene, naphthalene, gasoline, diesel and motor oil.
The analytical results were reviewed by Hannon and discussed by phone with TetraTech employees Ben Wienk and David Bertolacci on August 31, 2010. Hannon informed TetraTech that based on the results of the confirmation samples, no further sampling of the excavation was needed and the excavation could be backfilled.
TetraTech’s analysis of the soil samples for volatile organic compounds, semi-volatile organic compounds, and total petroleum hydrocarbons showed concentrations of benzene up to 17.3 I-Ig/kg, ethylbenzene up to 3.2 I-Ig/kg, toluene up to 17.2 I-Ig/kg, xylene up to 7.54 I-Ig/kg, total petroleum hydrocarbons diesel range up to 32.2 mg/kg, and total petroleum hydrocarbons motor oil range up to 149 mg/kg. 1,2,4-trimethylbenzene was detected in only one sample at 5.91 pg/kg. Based on the analytical results of the stockpiled soil, TetraTech determined that the soil was non-hazardous and it was transported to TPS Technologies in Adelanto, California for disposal on August 20 and 21, 2010.
Based on the high benzene concentrations detected in the contents of the drums, the waste materials placed in the roll-off-bins were classified as hazardous. On October 11, 2010, the sealed bins, containing waste product, drums and debris, were transported and disposed of at Rineco in Benton, Arkansas.
Kurt Bechtold, the executive director at the Riverside office of the California Regional Water Quality Control Board for the Santa Ana Region, told the Sentinel, “Our staff oversaw and verified the adequacy of the clean-up. We were satisfied the county had done a thorough job of cleaning up. The material that was found in the drums was never conclusively identified. It was a jellied petroleum substance consistent with napalm. There was a chemical analysis to figure out what was in it and there were a number of petroleum compounds present in the material. The surrounding soil was removed. It appeared that the contamination of the soil was fairly minimal. The material in the drums was not particularly fluid. It was described as resinous in nature, which meant that was not particularly mobile in the environment. Nearly all of the material appeared to be contained within the drums. There was some amount of contamination in the vicinity of drums but the contaminated soil was removed with the drums.”
The county had acted responsibly with regard to the circumstance, Berchtold said. “We are satisfied the county has adequately investigated any potential source on the airport property and the county is adequately addressing the contamination found to date,” he said.
Chino Airport is an asset of the county overseen by the county’s airports division. Another problem there consists of a plume of perchloroethylene (PCE) and trichloroethene (TCE) that originated at Chino Airport migrating south-southwest from the western end of the airport property. The plume has reached a point about 7,500 feet from the airport, just south of Bickmore Avenue. There are 28 permanent wells in the area and 33 additional sample ground water collection probes that have monitored the extent of contamination and its movement. The highest level of TCE detected is 420 parts per billion. The allowable California safe drinking water standard is 5.0 parts of TCE per billion, such that some of the water in the basin is testing at a level that is 84 times higher than is considered safe.
There are multiple points within the plume where readings of over 100 parts per billion have been encountered.
Some of the plume is being captured by a desalter project that has wells within the area of the plume. The desalter plant was built to capture water and remove the high concentration of salt and nitrates present in the water as a consequence of the significant number of dairies in the area before the water reaches the Santa Ana River. The plant also pulls in TCE, so a portion of the TCE is not making it into the river but the desalter plant is inadequate to the task of effectuating the whole clean-up. The county is working with TetraTech in an effort to devise a plan to remediate the TCE and PCE contamination. That plan has yet to be effectuated.
Berchthold said the TCE and PCE contamination, which is likely to have originated as a consequence of the use of those solvents on aircraft at the airport, is unrelated to the drums of what appears to be napalm that were buried at the airport.