When Alfred Lee started milking cows, his farm was a typical Wisconsin dairy operation. Today, the incorporated family business has embraced large-scale farming practices and ventured into a much bigger operation than Lee had ever dreamed. Large dairy barns use water for many reasons, some more obvious than others. For cows to produce milk, it is, of course, necessary for them to drink water – about 25 gallons each per day. At Norswiss Farms Inc., in Rice Lake, Wis., geothermal cooling is just as important as drinking water.

In total, five wells will supply water to the Norswiss farm. Aqua Service Inc., of Cameron, Wis., has drilled wells supplying 10 gallons per minute (gpm), 30 gpm and 50 gpm. But, as the cow herd continues to grow, so has the quantity of water needed on the farm. With the first of the two 100-gpm wells already completed for milk cooling and animal watering, the second 100-gpm well currently is being drilled, and will be used for the cow cooling system. To cool the animals in the summer months, a misting system will be installed in the 350-foot-by-1,000-foot dairy barn that currently is under construction.

Some 42 Million Gallons

The new barn will house 3,400 head of Holstein milk cows, with an additional 1,200 head in a separate barn. With 4,600 head consuming 25 gallons per day, that equals roughly 42 million gallons of drinking water per year. When temperatures heat up, cows get stressed. A research study published by Kansas State University, “Questions and Answers about Heat Stress,” indicates stressed cows consume 6 percent to 16 percent less food than thermal-neutral lactating cows. This equates to a 30-percent to 50-percent reduction in the efficiency of energy utilization for milk production, according to the study. To evaporate 1 pound of water off a cow’s back requires 1,000 BTUs, which the study says comes out of the cow’s body. As air is a poor conductor of heat compared to water, it is more efficient to evaporate water from a cow than to cool the air. Norswiss is installing misters and fans to cool the cattle, hence reducing cow stress in the hot Wisconsin summers.

The comparison to Alfred Lee’s advancement in the dairy business is about as great as that in the drilling technology from when Jerome Wojtkiewicz started Aqua Service in 1969 with a cable-tool rig. Today, the full-service drilling and well service company is operated by Wojtkiewicz’s son-in-law, Jeff Haughian. The company has grown over the years with the purchase of its first rotary drill rig in 1975 and Wojtkiewicz mounting his first casing hammer in 1977.

Haughian compliments his father-in-law, who was only the second driller in Wisconsin to use the casing hammer. Although mostly self-taught, Wojtkiewicz mastered the technology to the point that, “not only did he create a successful business for himself, he has converted many other drillers to air rotary drilling with a casing hammer,” says Haughian.

Varied Conditions

“We’ve really got it all when it comes to rock in northwest Wisconsin – igneous, sedimentary and metamorphic,” explains Haughian. With sandstone being the most common bedrock they drill, it can be encountered from a few feet to nearly 400 feet below ground surface. “About 90 percent of the time, we advance our casing with the casing hammer right from ground surface, through the overlying mixture of sand, gravel, clay, cobbles and boulders,” he adds.

Most wells are cased with 6-inch steel from surface to the optimum water-bearing formation, either sand and gravel or bedrock. Using the casing hammer is an advantage over mud drilling because it allows for greater borehole stabilization through the unconsolidated formation. Also, water from the unconsolidated aquifer can be analyzed as the casing advances. “If you’re drilling with mud, you can’t stop to test the quality of water at discrete places in the sand and gravel formation. We also feel that knowing exactly what the formation is greatly enhances the yield of screened wells,” notes Haughian. In this area, some unconsolidated aquifers have multiple water-bearing layers, each with its own unique water quality. The main water-quality concerns are high nitrate or iron levels.

Residential wells in the area range from 40 feet to 400 feet in depth. “It all depends on what the glacier put beneath your feet in a particular location,” explains Haughian. Commercial and irrigation wells can be drilled deeper than residential wells to get the desired flow of water.

At Norswiss Farms, the 100-gpm wells will run about 400 feet deep. The initial 200 feet will be mud drilled with a 10-inch bit, with 6-inch steel casing cement-grouted in the 10-inch hole. “It is a Wisconsin well code requirement that a well producing 70 gpm or more have at least 60 feet of cement grouted casing,” Haughian points out. Before the casing is cemented, the casing hammer gives the casing a firm seat in the sandstone. Wells without cement grout are sealed with granular bentonite as the casing is driven to prevent ground water contamination.

Getting There

The casing hammer method of drilling Aqua-Service uses for residential wells is to advance the drill bit 2 feet to 3 feet out in front of the casing, clean the hole with air and water, then pull it back into the casing before advancing the casing with the casing hammer. Once the casing is lowered to the bottom, the process is repeated. “You don’t want to get too far ahead of the casing because you don’t want deviation in the hole,” Haughian explains. The 640-pound weight on the casing hammer has no problem driving the casing into the smaller diameter hole. There are times, though, when friction becomes too great and the process has to stop, but, according to Haughian, “Nearly 100 percent of the time, the casing hammer gets you to where you’re supposed to be.”

Aqua-Service has installed up to16-inch casing with its casing hammer, and different models are available based on the work to be done. The casing hammer and handling system were installed by Aqua’s distributor, Atlas Copco’s Milwaukee branch, when the Aqua-Service purchased a new Atlas Copco TH60 drill. Unique to this rig is the swing-out rail system. The casing hammer travels on these additional rails, mounted to the outside of the tower. The rails hydraulically swing out, thus swinging the casing hammer out from over the hole, to allow for easier setting of casing and drill rod-handling. Haughian uses the Weldco-Beales casing hammer, which he sells as a dealer. The other feature Haughian is impressed with on the new TH60 is the air regulation system. “It makes developing out a sand and gravel aquifer prior to screening so much faster when you’re able to increase and decrease air pressure and volume with the turn of a button, rather than try to regulate it with engine rpm,” Haughian offers.

So, whether it’s telescoping a screen in a sand and gravel aquifer, or driving the casing to a firm seat in bedrock, using an air rotary drill with a casing hammer is much the same as cable-tool drilling.

“Ultimately, this process isn’t much different than the cable drill my father-in-law started with 40 years ago,” says Haughian. “Now we’re just doing it 10 times faster.”