PROMONTORY, Box Elder County — Concerns over potential groundwater or soil contamination from ATK's testing of powerful solid rocket motors used in the space shuttle program prompted a state and federal inquiry to determine if there were any harmful public health effects.
The site investigation, done by the Environmental Protection Agency in tandem with the state Division of Environmental Response and Remediation, found no long-term health or environmental risks to soil or water that would come from the result of rocket motor testing.
The agencies closed their investigations in December after holding an open house in the neighboring community of Tremonton, where residents were briefed on sampling results and actions taken in the inquiry.
The probe was prompted by a resident who petitioned the EPA in August 2010, asking for sampling to determine safety or relative risk related to ATK's test firing of solid rocket motors. The large-scale motors produced by ATK are tested a couple times a year to ensure their safety when launching astronauts or payloads into space.
"Basically, what we were trying to determine was if there were any long-term residual impacts or effects as a result of that test-fired soil," said Dale Urban, the division's site assessment program manager.
Urban said the tremendous heat and energy released during the motor testing blasts away soil and rock, essentially pulverizing the natural limestone rock at the test site.
The tests not only draw a crowd of space industry executives and media, but attract busloads of children and others who want to feel the ground rumble and watch the spectacular plumes fill the sky.
Urban said environmental regulators took samples from nine drinking wells and six soil samples in 2011. The testing spanned private well locations in the towns of Penrose and Thatcher and community wells that serve Marble Hills, Bothwell, Thatcher-Penrose, West-Corrine and the Bear River Water Conservancy District, which supplies agricultural and municipal water to much of the area.
Scientists were looking to determine if samples from the wells, groundwater and soil contained elevated levels of metals or other contaminants. The EPA and state air quality regulators also collected airborne debris samples during rocket motor testing.
Analysis of some of the debris indicated a presence of high pH, which can cause brief irritation and a burning association if it comes in contact with the skin, Urban said. The pH may become neutralized as it is falling from the sky and mixing with native soils, he said.
As a precaution, the division recommends avoiding direct contact with the debris during any future testing events.
The state and federal governments organized the informational open house in early December to update residents on their findings, a move Urban said officials believed was important in the investigation.
"This was beyond the typical response. We normally just provide a copy of the lab results and reports," he said, "but the EPA felt it was appropriate to follow up with community outreach."
Urban said ATK completed a major hillside modification project in early 2011 that may be helping corral the debris on its property.
The flame trench at the primary testing site was deepened and expanded by excavating 15,000 tons of rock and sand that were hauled away in 1,000 dump truck loads, according to ATK officials. The area was also revegetated.
ATK spokeswoman Trina Helquist said the expansion has been effective in helping to reduce the amount of debris that becomes airborne, adding that the company also follows strict protocols to assess wind and weather conditions.