IA Well Driller cheat sheet

Iowa Code chapter 455B gives the DNR authority over water wells; the technical standards sit in 567 IAC chapter 49 (Water Well Construction and Closure), covering permits, location, casing, grout, disinfection, and plugging.

Construction, reconstruction, and plugging of a well may be performed only by a DNR-certified water well contractor, or by workers under that contractor's direct on-site supervision.

A site-specific construction permit must be obtained from the DNR before drilling starts; the permit fixes the approved location and use and must be available at the site while work proceeds.

A public water supply well needs a separate DNR construction permit under 567 IAC chapter 43 in addition to the nonpublic well authorization.

Every well is logged: total depth, formation changes, casing and screen intervals, grout method and volume, static water level, and yield, then submitted to the DNR as the well construction report.

Closure work is documented the same way; the plugging report records method, materials, seal depths, and date, and the owner keeps a copy.

Enforcement tools include suspension or revocation of certification and administrative penalties; drilling or plugging without certification is a violation of chapter 455B.

Where a county board of health or local ordinance sets a stricter siting or construction standard than the state rule, the stricter requirement controls.

Isolation distances are horizontal, measured from the well casing to the nearest point of the contaminant source, not from the property line or the pump house.

50 feet: minimum separation from a septic tank and from sanitary sewer lines.

100 feet: minimum separation from a soil absorption (leach) field, manure storage, feedlot or barnyard, and fuel or pesticide storage.

200 feet: minimum separation from a sanitary landfill, wastewater lagoon, or wastewater land-application area.

Avoid surface water, sinkholes, and drainageways; where the site lies in a mapped floodplain, the casing must finish above the 100-year flood elevation.

Put the well upgradient of contaminant sources on ground that falls away, then grade and mound the surface so runoff leaves the wellhead rather than ponding at it.

In northeast Iowa karst limestone, solution openings and sinkholes are direct conduits to groundwater: keep the well away from them and grout casing into sound bedrock.

Before fixing the site, review the DNR source water assessment and, for community systems, the wellhead protection area; note nearby underground tanks, animal feeding operations, and chemical storage.

Formation drives method choice: hollow-stem auger for unconsolidated glacial drift, mud rotary for deep sand, gravel and bedrock, air rotary or cable tool for cavernous limestone and boulder zones.

Drilling fluid must hold the borehole open and lift cuttings, but excess mud weight invades the producing sand and plugs it, cutting specific capacity.

Iowa sequence top-down: Pleistocene glacial till and outwash, alluvial sand and gravel in modern river valleys, Paleozoic limestone/dolomite/sandstone aquifers, and Precambrian granite and quartzite in the northwest.

Casing is set through the unconsolidated zone and seated into a competent confining layer or bedrock; site geology, not a fixed statewide depth, sets the casing point.

Identify zones of poor-quality water (high sulfate, iron, brackish) and grout them off so they cannot mix with the producing aquifer.

Borehole diameter must leave adequate annular clearance, typically at least 2 inches, so a continuous grout column can be placed around the casing.

Artesian or flowing conditions must be controlled with weighted fluid or casing before grouting; uncontrolled flow dilutes and displaces the seal.

Record first water struck, static level, and lost-circulation zones: they determine screen placement, seal depth, and where the pump can safely sit.

Casing must be new, watertight, and approved for potable water (NSF/ANSI 61 PVC or steel) with joints that seal: flush thread, welded, or properly coupled.

The casing top finishes at least 12 inches above finished grade, the annulus is grouted to the surface, and the ground is mounded to shed water away.

Acceptable annular seal materials are neat cement grout (cement plus no more than about 6 gallons of water per sack), bentonite grout slurry, or bentonite chips; drill cuttings, soil, and sand are not acceptable in the seal interval.

Grout is placed from the bottom up with a tremie pipe or positive-displacement pump so the discharge stays buried in rising grout; never dump grout from the top of the annulus.

The grout column must be continuous over the full sealed length; if the annulus caves, ream the hole rather than allowing a bridge that leaves an open channel.

Screen slot size is selected from sieve analysis of the formation sample and matched with a graded gravel pack in alluvial sand and gravel.

The casing-to-screen connection must be watertight with a reducer or packer so formation material cannot enter above the screen.

In bedrock wells an open borehole may serve as the intake, but the casing must be grouted into competent rock above the water-producing fractures.

Centralizers keep the casing centered in the borehole so the grout thickness is uniform on all sides.

Development continues until the discharge runs clear; methods include surging, jetting, bailing, airlift, overpumping, and brushing to break the mud cake.

Over-development of a fine-sand aquifer can pull fines permanently; match development energy to the formation gradation.

Disinfect after construction, repair, or pump replacement with a chlorine solution strong enough to leave a measurable residual, commonly 50 to 100 mg/L, held 12 to 24 hours.

Chlorine demand rises with turbidity, iron, and organics, so verify the residual by test rather than assuming the calculated dose was effective.

Pump to waste until the chlorine residual is gone before sampling, and draw the sample at the wellhead tap ahead of softeners, filters, and treatment.

Use a sterile bottle, do not rinse it, chill the sample, and deliver it to a certified laboratory within about 30 hours, with well identification and collection date recorded.

Total coliform present means unsatisfactory: re-disinfect, inspect the cap and grout for defects, and retest. E. coli present is an immediate health hazard requiring a boil-water advisory or treatment.

Iowa new-well testing covers coliform bacteria and nitrate; results go to the owner, and to the DNR for public water systems.

A pitless adapter is a watertight casing fitting that carries the discharge line out below frost depth, roughly 3 to 5 feet in Iowa, so the well can be sealed at the surface without a pit.

Pitless units must be approved for potable water and matched to casing material: welded or strapped body on steel casing, saddle-type adapter on plastic casing.

The well cap must be vermin-proof and vented with a screened, downward-facing vent; a loose, cracked, or missing cap is a direct contamination pathway.

Set the pump above the screen and off the bottom, checked against static level, pumping level, and specific capacity, to avoid sand and cavitation.

Install a check valve directly above the pump and set pressure-tank precharge about 2 psi below cut-in, for example 28 psi on a 30/50 switch.

Size wire and breaker from motor amps, voltage drop over the setting depth, and NEC rules; bond the casing and ground the circuit.

Verify the completed installation by pump output, drawdown, cut-in and cut-out pressures, and absence of air or sediment in the discharge.

A well is abandoned when it is no longer used, is unusable, or is not maintained in a sanitary condition; Iowa law requires plugging to protect the aquifer.

Plugging is performed by a certified well contractor, usually after removing the pump, drop pipe, and any obstructions from the borehole.

The preferred seal is neat cement or bentonite grout placed by tremie from total depth upward; sand or gravel may fill only below the seal and never across a confining layer.

Steel casing that cannot be pulled is perforated, ripped, or cut off and the surrounding space grouted so no open annular channel is left behind.

Casing is cut off below final grade, typically about 3 feet, the remaining stub filled with grout, and the site restored and graded to drain.

Flowing or artesian wells require the flow to be controlled before grouting; a packer and heavier grout keep the seal in place against pressure.

File the plugging report with the DNR recording location, depth, method, materials and quantities, and date, and give the owner a copy.

An abandoned well may never be converted to a drainage or waste-disposal hole; that creates a direct, uncontrolled path to groundwater.

Notify Iowa One Call by dialing 811 at least 48 hours before excavation, wait for markings, and hand-expose utilities inside the marked tolerance zone.

OSHA 1926 Subpart P: a protective system is required at 5 feet of depth, spoil and equipment stay at least 2 feet back from the edge, and a ladder is placed within 25 feet of travel in trenches 4 feet or deeper.

A competent person inspects the excavation daily and after rain; standing water or tension cracks mean stop work until it is made safe.

Rig setup requires level, stable ground and fully deployed outriggers, with OSHA power-line clearance maintained (10 feet for lines up to 50 kV, more at higher voltages).

Stay clear of rotating augers, drive shafts, and cathead lines: no loose clothing, no hands near the kelly, and lockout before servicing.

Drilling mud, cuttings, and development water are contained, not released to waters of the state, storm sewers, or roadside ditches; use a settling pit or frac tank.

Land application of drilling water needs landowner permission, a vegetated buffer, and no runoff to streams; a construction stormwater NPDES permit is required where an acre or more is disturbed.

Fuel and chemicals are stored in secondary containment with a spill kit on site, and releases are reported to the DNR promptly.

Chlorinated development or disinfection water is dechlorinated or land-applied rather than dumped, because high chlorine is toxic to aquatic life.