Investigating CAFOs with Geoprobe® Equipment and Direct Push Methods

Cattle have been in the spotlight lately. A few years ago, Clara Peller wanted to know “Where’s the beef?” The dairy industry asks if we’ve “Got Milk?”, and the beef industry tells us, “Beef! It’s What’s For Dinner!”. Today, television proudly announces that happy cows live in California! What makes these beefy bovines so popular? Americans are in love with hamburgers; so much so we consume more than 14 billion burgers per year! That translates in to a lot of cattle in feedyards around the nation, and especially in Nebraska. If you add dairy, pork, and poultry to the equation, waste management, or more appropriately nutrient management, at Concentrated Animal Feeding Operations (CAFOs) becomes extremely important.

The U.S. Environmental Protection Agency (EPA) divides CAFOs into large, medium, and small facilities based on the number and types of animals that are maintained at the facility. So what is done with all of the waste? Manure is a source of nutrients, and is applied to cropland as part of the rancher’s/farmer’s nutrient management plan. Depending on the type of animals and the methods of housing, manure may be handled in either a dry or liquid form. Liquid manure is either “treated” in an anaerobic lagoon or stored for application to cropland in earthen, concrete, or steel structures. CAFOs exposed to storm water must construct runoff control structures designed to catch and hold a specified volume until it, too, can be applied to cropland. If waste control structures are not designed and managed properly, there is the potential that local groundwater may be impacted. The contaminants that are most likely to impact groundwater at a CAFO include nitrates, phosphorous, ammonia, and chlorides. Several states have developed, or are developing, regulations on groundwater quality near CAFOs. Nebraska, however, is one of the very few who are researching the issue so as to craft guidance for investigating potential impact on groundwater from waste control facilities located at CAFOs. Surface water impacts from CAFO discharges are regulated under the National Pollution Discharge Elimination System (NPDES) program.

Richard Holmgren (left) and Steve Knobbe run HPT logs using a Geoprobe® 6625CPT machine near one of six lagoons at a Concentrated Animal Feeding Operation (CAFO) site in Nebraska. At the request of the Nebraska Department of Environmental Quality (NDEQ), six Geoprobe® Field Team members demonstrated direct push equipment and tooling for NDEQ staff.

So what is the connection between Geoprobe Systems® and CAFOs? Dave Miesbach, Groundwater Unit Supervisor for the Nebraska Department of Environmental Quality, Water Quality Division, requested a demonstration of Geoprobe® equipment earlier this year to find out if direct push tooling could be useful for investigating the subsurface at a CAFO facility. Dave selected a 10,000-head beef facility as the demonstration site. According to Dave, the subsurface at the facility consisted of about 50 feet of alluvial sediments (largely sand and gravel with some silt and clay) overlying weathered bedrock.

In mid-June, six Geoprobe® field team members mobilized to the Nebraska demo site. They equipped themselves with a 7720DT and 6625CPT machine along with the Hydraulic Profiling Tool (HPT), DT325 and MC5 soil sampling systems, SP16 groundwater sampler, a GS2000 grout/injection machine, and the pneumatic slug test system. “The field demonstration provided valuable subsurface information,” Dave said. “The machines and tooling were a great fit for the site. We’re excited about using the Geoprobe® tools and methods to help perform groundwater and subsurface investigations at CAFOs in Nebraska.”

Jeff Gottula (left), Geologist with the NDEQ Water Quality Division; Tom Christopherson, Program Manager for Water Well Construction with the Nebraska Department of Health and Human Services; and Dave Miesbach, Groundwater Unit Supervisor with NDEQ Water Quality Division, participated in the two-day field demonstration.

The investigation was a cooperative research project involving Nebraska Cattlemen, USDA - Ag Research Service, Settje Agri-Services & Engineering, and the Nebraska DEQ. The Nebraska Cattlemen’s lead role in this project is an example of their proactive leadership in protecting the state’s natural resources. Chuck Folken, a feedyard owner/ operator, serves as Chairman of the association’s Natural Resources and Environment Committee, and Duane Gangwish is Vice President of Environmental Affairs for the Cattlemen.