Northwest Arkansas well water questions, answered.

There is no single number. Most home wells here draw from the Boone limestone of the Springfield Plateau aquifer, and the depth depends on where the bit meets water-bearing fractures and openings in that rock. Two wells a few hundred yards apart can finish at very different depths.

The best guide is the record of nearby wells. Arkansas requires a construction report for every well, so a local driller has a good sense of what neighboring properties hit. Some wells go much deeper to reach the older Ozark aquifer below, but that is a different, more expensive kind of well.

Because of the chert. The Boone Formation is limestone layered with chert, a flint-hard rock that wears bits and slows the drill. Add the red, rocky clay on top and the open cavities and fractures of karst, and every hole is a little different.

That is also why experience in this ground matters. A driller who knows where the clay gives way to rock, how to case through broken ground and how to seal the casing properly is protecting your water for decades.

Mostly depth, ground conditions and casing. A deeper hole costs more, broken or cavernous rock can need more casing and more time, and the pump, pressure tank and water line to the house are separate costs on top of the drilling.

Access matters too: a rig needs a reasonable path to the spot. Call with the property location and what the well will serve, and you’ll get an honest picture before work starts. We don’t publish prices because no two Ozark holes are the same.

Somewhere uphill or away from contamination sources, and at the distances Arkansas requires: at least 100 feet from a septic tank, cesspool, seepage line or manure pile in typical clay or loam soils, and at least 10 feet from buildings and power lines.

Those septic distances double in highly pervious gravel. Keep the well out of low spots where water stands after a storm, and leave room for a rig and, later, a pump truck to reach it.

The drilling itself usually takes a day or a few days, depending on depth and rock. Scheduling, weather, access and how fast the ground dries out after rain often matter more than the drilling time.

If you’re building, call early, before the driveway and foundation are in, so the well can go where it should rather than where it fits.

Often, yes, if you plan to water a lot of ground. An irrigation well is built for volume over a season, and Arkansas rules require an irrigation well to be at least 100 feet from any well producing drinking water.

Irrigation wells are also treated differently in the rules: they don’t have to be disinfected like a drinking-water well, which is one more reason not to drink from one.

The Arkansas Department of Agriculture’s Natural Resources Division, through its Water Well Construction Committee (the program long known as the Arkansas Water Well Construction Commission). Anyone who contracts for or performs well construction or pump installation must hold, or work for someone who holds, an Arkansas Water Well Contractor License.

Individual drillers and pump installers also need an Arkansas Certificate of Registration. Licensing has been required since Act 641 of 1969.

Use the state’s “Find a licensed water well contractor” dashboard or the downloadable contractor lists on the Arkansas Department of Agriculture’s Water Well Construction Committee page. Each entry shows the license number, home county and license category.

Bob Wade Drilling Co. appears on the 2025–2026 list as license C001315, Benton County, in the Drill Systems Only category.

There are three: Drill and Pump Systems (all well construction, including pump installation), Pump Systems Only, and Drill Systems Only. A Drill Systems Only contractor drills and builds the well; installing the pump is done under a Pump Systems license.

When you hire for a new well, ask how the pump, pressure tank and line to the house will be handled, and by whom.

Yes. The contractor must file a construction report with the state within 90 days, including the well’s latitude and longitude, and must give the owner a copy on request.

Keep that copy with your deed. It records the depth, casing and other details that make future pump work, testing and a home sale easier.

In rock, the casing must go at least 10 feet below the surface or at least a foot into the formation, and it must be sealed with cement or bentonite grout. The casing has to stand at least 8 inches above the ground, or 24 inches above the highest flood level where flooding happens.

Those details keep surface water, which in karst country can carry bacteria straight down, from running along the outside of the casing into your water.

Have it plugged properly. An open or abandoned well is a direct path for surface water into the aquifer and a danger to children and animals. Arkansas rules set out how unused wells must be filled and sealed, and a report must go to the state within 90 days of plugging.

Don’t drop trash, rock or dirt into an old well. That doesn’t seal it, and it can make proper plugging harder.

Karst is limestone country where water has dissolved the rock into fractures, caves, sinkholes and springs. Northwest Arkansas is classic karst. It holds a lot of water, but water from the surface can reach the aquifer fast, with little filtering on the way.

The U.S. Geological Survey notes that contaminants can move quickly into Ozark aquifers through sinkholes and losing streams. A sealed casing, a good site and regular testing are how a well owner stays ahead of that.

In karst, storm water can travel from the surface to the aquifer in hours or days through sinkholes and open fractures, carrying soil, bacteria and whatever was on the ground. Cloudiness after a big rain is a warning sign.

If your water suddenly changes color, smell or taste, or the well area flooded, don’t drink it until it has been tested. Use bottled water and follow the Arkansas Department of Health and your local health unit. A well that clouds up after every storm may have a casing or seal problem worth having looked at.

It’s not a good idea. A sinkhole is a direct drain to the rock below, so whatever washes into it can reach the aquifer quickly. Never use a sinkhole as a dump for trash, brush, chemicals or dead animals.

When siting a new well, keep it well away from sinkholes and losing streams, and don’t let surface water pond around the casing.

At least 100 feet from a septic tank, cesspool, seepage line or pit privy in clay or loam soils, under the state’s well construction rules. In highly pervious gravel, the distances double.

In karst country these distances are a minimum, not a target. If you’re planning both a well and a septic system on a new lot, place the well first in your planning and keep it uphill and as far from the system as the lot allows.

It can be. USGS sampling found higher nitrate in the shallow Springfield Plateau aquifer than in the deeper Ozark aquifer, and higher levels where more of the land is in agricultural use. A University of Arkansas study found more nitrate entering in wet seasons.

Sources include fertilizer, animal waste and septic systems. If there are infants or pregnant women in the home, test for nitrate. The Health Department’s lab tests only bacteria, so use a certified private lab for nitrate.

Usually not. USGS sampling in the Ozarks found that water from springs is generally more susceptible to surface contamination than water from wells. A spring is the aquifer’s outlet, fed by whatever drained into the karst upstream.

If your home uses a spring, test it often and treat it as surface water. A properly cased and sealed well is usually the more dependable source.

Start with your local health unit. The Arkansas Department of Health’s Water Microbiology Laboratory tests private well samples for total coliform bacteria and E. coli; you pick up a collection kit at the local health unit, and the sample must reach the lab within 30 hours of collection.

The state lab doesn’t test minerals or chemicals. For nitrate, hardness, iron or other chemistry, use a certified private laboratory.

At least once a year for bacteria, and any time the water changes color, smell or taste, after flooding, after the well is opened for work, or when there’s a new baby in the house (add nitrate).

In karst country, testing after a very wet spell is worth doing even if the water looks fine.

Because it comes from limestone. Groundwater moving through the Boone limestone dissolves calcium and magnesium, so most wells here give hard water that leaves white scale on fixtures and shortens water-heater life.

Hard water is a nuisance, not a health hazard. A water test tells you how hard it is, and a softener or scale treatment can be sized from that number.

Shock chlorination means putting a strong chlorine solution into the well and plumbing to kill bacteria, letting it sit, then flushing it out. Arkansas rules require new and repaired drinking-water wells to be disinfected before use, and pump installations to be chlorinated to at least 50 ppm for 24 hours.

It’s also used after a positive bacteria test or flooding. Retest afterward. If bacteria keep coming back, chlorinating again won’t fix the cause: look for a bad cap, a cracked casing, a poor seal or a contamination source nearby.

That smell is usually hydrogen sulfide, and at the levels found in household water it’s usually a nuisance, not a health hazard. It can come from the groundwater itself or from bacteria in the water heater.

If the smell appeared suddenly, or came with a change in color or taste, stop drinking it until it’s tested. Never treat a well with chemicals that aren’t made for drinking water.

Check the well pump’s breaker in the electrical panel. If it has tripped, reset it once. If it trips again, leave it off and call a licensed pump installer.

Never open the pressure switch, the pump control box or the wiring at the wellhead: they are live at 240 volts. No DIY pump wiring and no pulling the pump yourself.

That’s short cycling, and the usual cause is a pressure tank that has lost its air charge or has a failed bladder. It wears out the pump and the pressure switch quickly.

Have it checked soon. Pump and pressure-tank service is done under an Arkansas pump systems license.

Commonly around ten to fifteen years, depending on the tank, how hard it works and the water. Signs it’s going: short cycling, a waterlogged tank, sputtering faucets or rust at the seams.

A larger tank means fewer pump starts, which helps both the tank and the pump last.

Often eight to fifteen years or more. Short cycling, sand or grit, low water and lightning all shorten that. A pump that runs constantly or trips its breaker is telling you something.

Repeated pump failures in a short time can point to the well itself, such as a falling water level or sediment, which is worth checking before buying another pump.

Plan ahead. An electric well pump stops when the power does, which Northwest Arkansas learned in the January 2009 ice storm. Store drinking water, keep some in the tub for flushing, and talk to an electrician about a properly installed generator connection.

Never backfeed a house through an outlet. That can kill a lineworker or a neighbor.

The well itself rarely does, but exposed pipes, a pressure tank in an unheated shed and the line at the wellhead can. Insulate and, where it’s safe and done by a qualified installer, heat the well house or pump room.

If pipes freeze, shut the water off and call. Don’t use an open flame.

It depends on where the nearest water main is and what the connection costs compared with a well. Much of Northwest Arkansas’s fast-growing city area is served by public water drawn from Beaver Lake, but acreage outside city and rural water lines still relies on wells.

Ask the local water provider whether a line reaches your lot and what the tap fee is, then compare it with a well. A well has no monthly bill but needs testing and occasional pump and tank work.

Ask whether there’s an existing well, ask for its construction report, and have the water tested for bacteria (and nitrate) before closing. Federal home loans such as FHA, VA and USDA commonly require a private-well water test.

For bare land, ask neighbors about their wells and check whether public water reaches the road. A licensed local driller can tell you what to expect in that ground.

Often yes, for irrigation or livestock, but rules vary by city and water provider, and some require the private well to be physically separated from the public system so it can’t backflow into it.

If you stop using a well entirely, it must be properly plugged rather than left open.

It can change the ground around it. New roads, rooftops and parking lots change how storm water runs off and where it collects, and in karst that can affect what reaches the aquifer.

Watch for changes after heavy rain, test yearly, and if a neighboring project changes drainage around your wellhead, have the site and casing looked at.