Most tests at depot negative
Although traces of diesel-related chemicals have been found in two recent soil and groundwater samples taken below BNSF Railway’s refueling depot, most other samples have shown no signs of contamination.
Both BNSF and officials with the Idaho Department of Environmental Quality caution against jumping to conclusions from the pair of tainted samples, which were gathered directly below the depot’s cracked refueling platform.
“Until we get all the information, we can’t really come to any conclusions,” said Marc Kalbaugh, site manager for DEQ. “There’s a lot of variables that need to be evaluated.”
Testing of vapor, water and soil samples is fast and furious as the railroad prepares for an April 5 court date in Coeur d’Alene, where the company is expected to present a case that the six-month-old depot can resume operations without further contaminating the region’s drinking water aquifer 160 feet below the site.
In December, fuel and oil from a crushed pipe were discovered to have been leaking unchecked into the ground. Last month, new leaks were discovered and a Kootenai County judge ordered the depot closed until the problems are fixed. BNSF has insisted the latest problems have been contained by a plastic membrane buried below the 35,000-square-foot concrete platform.
Recent lab tests cast doubt on the claim. Groundwater from a monitoring well drilled at an angle directly below the heart of the refueling platform – upstream, as the groundwater flows, from the crushed pipe found in December – has been found to contain traces of methylnaphthalene. The chemical is a hazardous component of diesel fuel that can leave a detectable odor at concentrations as faint as 10 parts per billion, according to the federal Agency for Toxic Substances and Disease Registry. Water sampled from other nearby wells has not shown any contaminants.
Trace amounts of petroleum have also been found in one of 12 soil samples taken beneath the outermost fuel barrier below the fueling platform, said Gus Melonas, a spokesman for BNSF. Eleven other soil samples have come back clean.
Melonas pointed out that the tainted groundwater was found to contain only one of diesel’s 24 components.
“BNSF is further analyzing samples collected to ensure accuracy,” Melonas said. “The data is not conclusive at this point.”
BNSF and the state of Idaho each take separate samples, which are sent to different labs, said DEQ’s Kalbaugh. Results from the spilled samples are compared to ensure accuracy.
Within a few days, results are expected from air vapor samples taken from a series of eight horizontal wells below the platform. The vapor samples should provide some of the most accurate indications yet of whether any fuel has breached the containment barriers, Kalbaugh said.
Specialized drilling rigs allowed crews to install the wells, which are capable of gathering air samples from just 10 feet below the underground fuel membrane. The tests will allow for rapid detection of any fuel leaks, Kalbaugh said.
Air, water and soil samples will play an important role in the upcoming court hearing and extra caution is being taken to ensure the samples are free from outside contamination. The drilling rigs are even using a special biodegradable lubricant rather than conventional grease, according to engineering reports on file with DEQ.
Construction crews continue to work around the clock to fix problems at the facility, including a major overhaul of the underground fuel containment barrier system. BNSF hopes the remodel will be finished by Monday to allow time for additional testing.
The depot is the fastest refueling station on the railroad’s northern mainline. It has been out of service for the past month following the emergency shut-down order from Idaho District Judge Charles Hosack.
Meanwhile, DEQ scientists and engineers are trying to make sense of the growing pile of lab reports before the April 5 court date. The agency is also trying to update its monitoring and inspection program for the depot. More than 20 new wells will make detecting any new leaks easier, but closer attention will need to be given to the extensive cracks identified on the refueling platform, Kalbaugh said. The cracks have been sealed, but they will need “frequent inspection,” he said.