IA Well Driller key terms

An Iowa DNR-issued credential authorizing a person or firm to construct, reconstruct, or plug water wells in the state. Certification requires documented experience, passing an examination, and renewal under departmental rules.

Written DNR authorization that must be obtained before constructing, reconstructing, or plugging a well. It identifies the site, describes proposed construction, and carries conditions the driller must follow.

The Iowa administrative rules chapter governing water well construction, siting, casing, grouting, disinfection, and closure. Drillers and inspectors use it as the enforceable technical standard for well work in Iowa.

A required record filed after well construction documenting location, depth, formations penetrated, casing and screen settings, grout placement, and yield. It feeds the state geologic and well-construction database.

A written DNR approval permitting an alternative to a specific rule requirement when strict compliance is impractical but groundwater protection is maintained. It must be granted before the affected work proceeds.

The required horizontal separation between a well and a potential contamination source such as a septic system, feedlot, fuel tank, or sewer line. Iowa rules set specific minimum distances that must be verified at siting.

The land surface contributing water to a public well or wellfield, delineated so contamination prevention efforts can be focused. Land uses within it may be managed voluntarily or through local ordinances.

Locating and completing a well so that floodwater cannot enter or inundate the wellhead. The casing must terminate high enough above expected flood levels and the cap must remain watertight.

Unconsolidated soil, sand, gravel, or clay lying above bedrock. Drillers case and seal through overburden because it is the pathway most likely to carry surface contamination downward.

A method using a rotating bit and circulating drilling fluid that lifts cuttings to the surface and stabilizes the borehole with a filter cake. Fluid properties must be controlled to avoid plugging producing zones.

A percussion method that fractures rock by repeatedly dropping a heavy bit suspended on a cable. It yields reliable formation samples and a clean borehole without drilling mud, but penetration is slow.

A continuous-flight auger with a hollow center through which sampling tools and casing can pass. It is common in unconsolidated material but requires planning to seal the annulus properly.

A low-permeability bed such as clay or dense rock that restricts water movement between aquifers. Grouting across it prevents one water-bearing zone from contaminating another through the borehole.

The escape of drilling fluid into a permeable, fractured, or cavernous formation so that returns at the surface diminish. It signals a high-permeability zone and may require additives or fluid changes.

Pipe installed in a borehole to keep the hole open and block contaminants from entering the well. Iowa rules set minimum material, wall thickness, and seating depth based on the well's intended use.

The gap between the borehole wall and the outside of the casing. Sealing it with grout creates the main barrier against surface water and shallow contamination moving down along the casing.

A cement-and-water mixture containing no sand, used to seal the annular space. It forms a strong, low-permeability barrier and is often specified for public water supply wells.

A clay-based sealing material supplied as slurry, chips, or pellets that swells when hydrated to seal the annulus. It must be placed so it does not bridge and leave voids.

Placing grout by pumping it through a pipe whose discharge end stays submerged in grout already in the hole. This displaces water upward and prevents dilution, bridging, and voids in the seal.

Uniformly graded sand or gravel placed between the formation and the screen to hold back formation particles while admitting water. Its gradation is selected to match the aquifer material.

A slotted or perforated section of casing that lets water enter from the aquifer while retaining filter pack material. Slot size is chosen from sieve analysis of the formation sample.

The work of removing drilling mud, cuttings, and fines from the filter pack and adjacent formation so the well yields clear water at full capacity. Methods include surging, jetting, and airlifting.

Introducing a strong chlorine solution into a well, circulating it through the piping, and allowing contact time before flushing. It disinfects the well and distribution system after construction or repair.

A laboratory analysis of a water sample that detects indicator bacteria signaling possible contamination. Unsatisfactory results require investigation, corrective action, and resampling before the water is accepted.

A laboratory measurement of nitrate-nitrogen in well water, commonly required for new wells and for real estate transactions. Elevated results near feedlots or cropland point to agricultural contamination.

Well yield divided by drawdown, usually expressed as gallons per minute per foot of drawdown. Comparing it over time reveals plugging, screen deterioration, or declining aquifer performance.

A fitting attached to the casing below the frost line that connects the pump discharge to the buried service line while keeping the casing watertight. It allows the well to be sealed at the surface.

A multistage pump and motor assembly installed below the water level in the well. Motor size and setting depth depend on yield, drawdown, and total dynamic head of the system.

The vertical pipe that carries water from a submersible pump up to the pitless adapter or wellhead. It must be sized for the flow rate and supported so the pump is not hung on its wiring.

A rubber or plastic device clamped to the drop pipe above the pump that cushions the assembly and limits spinning during startup. It also helps center the pump in the casing.

A vermin-proof, watertight cover that seals the top of the casing and admits the drop pipe and wiring through tight grommets. It keeps insects, surface water, and debris out of the well.

A well that is no longer used for its intended purpose, or one that is unusable, unsafe, or improperly constructed. Iowa rules require it to be plugged so it cannot act as a contamination pathway.

Filling a well bore with approved sealing material so the natural barriers between aquifers are restored. The method chosen depends on well depth, diameter, and whether casing is removed.

Placing dry bentonite chips or pellets into a well so they hydrate, swell, and seal the borehole, often used where slurry would be lost. Chips must be poured slowly to avoid bridging.

The free notification service drillers contact before excavating so utilities can mark buried lines. Iowa law requires advance notice before digging to prevent damage and injury.

Managing drilling fluids, cuttings, and development water so they do not reach streams, drainage tile, or wetlands. Discharge must follow permit conditions and be contained or dispersed on the site.

Entering a well pit or vault with limited access and possible oxygen deficiency or toxic gas. It requires atmospheric testing, an attendant outside, and a rescue plan before anyone enters.