Better Safe Than Sorry: NDA Member Helps Investigate Radiation Threat

According to the Environmental Protection Agency, radiation is all around us, emitted by the earth and even by our own bodies. However, higher levels of radiation may be harmful to humans and the environment. Radioactive materials and the radiation they emit are routinely used in industry, medicine, agriculture and research. It is the disposal of these wastes, combined with the radioactive wastes from nuclear power generation and nuclear weapons testing, that can lead to the pollution of the environment. Recently, Roberts Environmental Drilling, Inc. (Roberts) of Millstadt, Ill. completed a project to determine the extent of low-level radioactive contamination in the two largest lakes located in a Missouri wildlife area.

Roberts was contracted by MK-Ferguson, Weldon Springs, Mo., and Jacobs Engineering, St. Louis, Mo., to perform lake sediment sampling in lake number 34 and lake number 35 in the August A. Busch Wildlife Area, located near Weldon Spring, Mo. The possibility existed that some radioactive material may have reached the lakes due to runoff from the nearby Department of Energy's (DOE) former weapons plant site, The Weldon Springs Plant, located in St. Charles, Mo.

The DOE site has a history of radioactive contamination dating back to World War II. Radioactive materials related to the infamous "Manhattan Project," the name given to the development of the atomic bombs dropped on Hiroshima and Nagasaki, were processed and disposed of at the St. Charles DOE site. The Weldon Springs Plant was also one of the largest producers of trinitrotoluene (TNT) during the war, which contributed to a large degree of contamination on the several-hundred-acre site. The plant site is now in the final phase of clean-up and restoration.

The strict sampling specifications required for this job called for a series of borings, 314 total, to collect lake sediments and to penetrate a minimum of one foot into the natural soil beneath the sediment with at least a 95 percent recovery rate. Each boring was required to be located within one meter of the proposed sample location determined by a Global Positioning System (GPS) receiver with "real time" centimeter accuracy. The GPS consists of 24 Earth-orbiting satellites that allow anyone with a GPS receiver to determine precise latitude, longitude or altitude anywhere on the planet. GPS receivers measure the amount of time it takes a signal to travel from the satellite to the receiver using the speed of light as a reference. Due to the expense of GPS equipment and the cost involved to train or hire someone to operate the receiver, Roberts decided to subcontract for a GPS surveyor. They chose Kuhlman Design Group, a surveying and engineering company located in St. Charles, Mo., that owned a Trimble Pathfinder GPS receiver that met the specifications required.

Once awarded the contract, Roberts had 30 days to acquire and construct the equipment needed to access the lakes and collect the samples. Roberts purchased a rebuilt Mobile B-24 skid mounted rig and two used 24-foot pontoon boats for this project. They also modified a CME Continuous Soil Sampler; a tool specially designed to collect continuous soil samples in conjunction with hollow-stem auger drilling. Roberts modified this piece of equipment by extending the cutting shoes and fitting them with shop-made sediment retainers (designed by Roberts), creating finger-like catchers for the softer soil. Roberts also had a 10-foot sample barrel constructed. They purchased a few hundred feet of clear, polyethylene sample liner material and cut it to their specifications.

"We fabricated a few things we thought might work and, in the end, they worked quite well and made the job go more quickly and smoothly," said Charley Roberts, president and owner of Roberts Environmental Drilling, Inc.

Prior to commencing site work, Roberts mounted two additional pontoons for supplemental floatation under the pontoon boat designated for the drill rig. The contract required that Roberts be able to access areas in the lakes from 14 inches deep up to 20 feet deep. They cut a hole to drill through in the deck of the pontoon and mounted four removable spuds, or anchors, on each corner to secure the boat's location during drilling. The sampling crew used the other boat to process the sediment samples and transport personnel back to shore.

Although there was less sediment in the lakes than Roberts expected, it took time for them to set up at each location and push the sampler into new soil. The drill crew and GPS surveyor developed a navigation system for the drill-rig boat to ensure the boat stopped within three feet of the pre-established sampling locations. This was especially challenging during windy days.

Safety was of the utmost importance to Roberts during this project. Safety standards were strictly enforced, including extensive operator training, providing radiation education and training, and employing a high ratio of safety workers to operators to oversee all aspects of the project.

Roberts sampled 117 borings in lake number 34 and 197 borings in lake number 35. They completed the project in just less than two months, 30 days ahead of schedule and $38,000 under budget. In the end, no radiation levels were found that were above background, or naturally occurring, levels.

Upon completion of the project, MK-Ferguson provided a catered lunch for all personnel involved in the project and presented Roberts with a Certificate of Outstanding Performance from MK-Ferguson, Jacobs Engineering and the DOE.

"It's a great feeling to finish a job and exceed everyone's expectations," Roberts said.

Roberts Environmental Drilling, Inc. has been an NDA member for six years. It has been in business since 1992 and has 16 employees, seven drill rigs and several Geoprobes.

Resources:
Contracted by: MK-Ferguson, Jacobs Engineering
Location: Weldon Spring, MO
Drilling Contractor: Roberts Environmental Drilling
Tel: 618-476-7334
Fax: 618-476-3619
E-mail: redidrill@aol.com