NJ Well Driller cheat sheet

Rotary air (mud or foam) drilling suits hard rock and fractured aquifers; cable-tool drilling suits unconsolidated sand and gravel and boulder zones where circulation loss is severe.

Mud rotary uses bentonite or polymer slurry for hole stability and cuttings lift; air rotary requires a stable or cased hole above the water table to avoid collapse.

Casing advance systems (duplex, Odex, casing hammer) let the driller set casing through caving overburden while simultaneously drilling.

Reverse circulation moves cuttings up the drill pipe with high-volume, low-pressure flow; it is chosen for large-diameter wells and where formation damage from mud must be limited.

A top-head drive rig allows pipe handling without a kelly and is common for deep, large-diameter and angled holes.

Cuttings return velocity must exceed the settling velocity of the largest cuttings; check annular velocity when hole diameter increases or pump output drops.

Bit selection: tricone roller bits for hard formations, drag or PDC bits for soft to medium rock, down-the-hole hammers for hard abrasive rock.

Record drilling fluid weight, viscosity, and loss zone depths; lost circulation is a leading cause of hole collapse and must be remedied before continuing.

Minimum annular seal (grout) requirements in New Jersey generally extend from land surface to the top of the screen or the first water-producing zone, whichever is shallower.

Grout volume for an annulus equals pi/4 times (hole diameter squared minus casing outside diameter squared) times length, plus a calculated excess of roughly 10-25 percent.

Neat cement grout is commonly specified at 5-6 gallons of clean water per 94-lb sack; bentonite is added for shrinkage control and higher-solids mixes for void filling.

Screen slot size is selected so 40-50 percent of the formation material is retained; the slot opening is usually matched to the sieve analysis of the aquifer sample.

A gravel pack is placed where the aquifer is fine or uniform; the pack gradation is typically 4-6 times the D50 of the formation and the screen slot retains the pack.

Casing must be plumb and centered with centralizers so the grout annulus is continuous; an eccentric string creates thin spots that allow vertical leakage.

A wellhead must be sealed and vented; New Jersey requires a sanitary well cap and a flood-proof, vermin-proof seal at the surface.

Well yield testing should follow development; specific capacity equals pumping rate divided by drawdown and is a key comparison metric between wells.

Development goals: remove drilling fluid and fines from the screen and gravel pack, and increase hydraulic connection with the formation.

Surge block or surge plunger development works by cyclic pressure reversals; it is more effective than simple overpumping in screened wells.

Jetting with high-pressure water or air cleans screen slots and gravel packs; air-lift development is common in rock wells but can be less effective in fine sands.

Chemical rehabilitation uses dispersants (polyphosphates), acids for mineral scale, or chlorine for biological fouling; the choice must match the fouling mechanism.

Biological fouling shows iron bacteria sheen, sulfur odor, and declining specific capacity; shock chlorination followed by flushing is the standard first response.

Mechanical and chemical rehabilitation should be followed by a pumping test to verify recovery of specific capacity.

Overpumping during development risks pulling fines into the gravel pack and permanently reducing well efficiency.

Document pre- and post-rehabilitation specific capacity; a well that does not recover after proper rehabilitation may need redevelopment, re-screening, or replacement.

Submersible pump setting depth must keep the pump above the screen and below the estimated pumping water level, with margin for seasonal decline.

Total dynamic head equals static lift plus drawdown plus discharge pressure head plus friction losses in the drop pipe, fittings, and distribution.

Friction loss in the drop pipe increases with flow squared; undersized drop pipe is a common cause of poor performance.

Pump efficiency is best near the pump's design flow; throttling far from the design point wastes energy and can cause motor overheating.

A pressure tank's drawdown volume relates to precharge pressure and cut-in/cut-out settings; a tank precharge lower than cut-in pressure causes short cycling.

VFD or constant-pressure controllers reduce cycling and maintain steady pressure but require pump and motor ratings compatible with variable speed.

Check valve placement, torque arrestors, and cable guards protect the pump and drop pipe; a check valve near the pump prevents backspin and water hammer.

Electrical: verify voltage, phase, and motor amp draw against the nameplate; low voltage causes overheating and premature motor failure.

An aquifer is a saturated formation that yields water in usable quantities; an aquitard transmits water slowly and confines adjacent aquifers.

Porosity is the fraction of void space; specific yield is the drainable porosity, which governs how much water a unit releases under gravity.

Transmissivity equals hydraulic conductivity times saturated thickness; storativity is specific yield in unconfined aquifers and storage coefficient in confined aquifers.

Darcy's law: flow rate equals hydraulic conductivity times cross-sectional area times hydraulic gradient.

Theis and Cooper-Jacob analyses estimate transmissivity and storativity from pumping test drawdown data; Cooper-Jacob requires small drawdown relative to saturated thickness.

Cone of depression geometry depends on pumping rate, transmissivity, and boundary conditions; a nearby stream or recharge boundary flattens the cone.

Saltwater intrusion occurs where fresh water is drawn toward coastal wells; the Ghyben-Herzberg relation links freshwater head to the depth of the interface.

Recharge in New Jersey comes largely from precipitation infiltrating uplands; withdrawal from a well can capture nearby recharge or surface water rather than deplete storage.

New Jersey requires testing of new wells for coliform bacteria, nitrate, and other constituents; additional tests may apply for arsenic, iron, manganese, and volatile organics depending on the area.

Coliform presence indicates a pathway for contamination; it is a treatment and resampling trigger, not a health-based standard by itself.

Iron and manganese cause staining and taste complaints; treatment options include oxidation followed by filtration, greensand, or sequestration.

Arsenic in New Jersey groundwater is often naturally occurring; treatment includes anion exchange, adsorptive media, and coagulation-filtration.

Nitrate above the federal maximum contaminant level of 10 mg/L as nitrogen is a health concern, especially for infants; reverse osmosis and ion exchange are effective.

pH below 6.5 is corrosive and can leach metals; treatment includes acid neutralization with calcite or soda ash feed.

Hardness is reported as calcium carbonate equivalent; softening by ion exchange or sequestration is a treatment, not a health requirement.

Sample collection must use clean, approved containers and appropriate preservation; bacteria samples require sterile bottles and cool transport to the lab.

Abandonment requires removing or perforating obstructions, disinfecting, and filling the entire borehole with an approved sealant so vertical migration is prevented.

Approved sealing materials include neat cement grout, bentonite grout, and bentonite chips or pellets placed by tremie or dry methods appropriate to the hole.

Casing should be removed to the maximum practical depth or perforated so grout can fill the annulus and borehole; leaving an open annulus defeats the seal.

Sealing must extend from the bottom of the well to land surface, or to a specified depth where the well is under a structure or in a designated area.

Tremie placement from the bottom up avoids bridging and voids; free-fall placement of grout in a deep water column is not acceptable.

A sealed well must be documented with the sealant type, volume used, depths, and date; the record supports later land-use decisions.

Unsealed or improperly abandoned wells are direct pathways for surface contamination and must be reported and corrected.

Artesian or flowing wells require special attention because pressure can force sealant out; staged sealing and verification of the seal are needed.

New Jersey regulates well construction and abandonment under the Private Well Testing Act and the well construction rules administered by the Department of Environmental Protection.

A well permit is required before drilling; the licensed well driller submits the application and the permit number must be recorded on the well log.

Well records must be filed with the state within the required timeframe and include location, construction details, grout volumes, yield, and water quality results.

Licensing requires passing the state examination and meeting experience requirements; a licensed driller is responsible for the work performed under the license.

Private Well Testing Act requirements apply at the time of sale or lease of property served by a private well; the seller must test and share results with the buyer.

Wells must be located at required minimum distances from sources of contamination, septic systems, property lines, and buildings; verify the current setback table before siting.

Changes in ownership, well use, or abandonment must be reflected in state records; failure to file can delay property transfers.

Local health department approvals may be required in addition to state permits; check both before mobilizing.

Confined space entry requires atmospheric testing for oxygen, flammable gas, and hydrogen sulfide, plus a rescue plan and attendant.

Hydrogen sulfide and methane can accumulate in well pits and vaults; ventilate and test before entry, never rely on odor.

Lockout/tagout of pump and motor circuits is required before servicing; verify de-energization at the control panel.

Drilling fluid and cuttings must be contained and disposed of according to state and local rules; never discharge to storm drains or wetlands.

Fuel and oil storage on site requires secondary containment and spill response supplies; report releases immediately.

Hearing protection is required around air compressors and drill rigs; noise levels commonly exceed 85 dBA at the operator position.

Lifting operations require rated slings and shackles, inspected rigging, and exclusion zones beneath suspended loads.

Site restoration includes sealing unused boreholes, removing debris, and stabilizing access roads and pads to prevent erosion.

Maintain a job file per well containing the permit, drilling log, grout records, development records, pump test data, water quality results, and as-built construction details.

Contracts should state scope, payment terms, change-order procedures, exclusions, and warranty limits; verbal changes should be confirmed in writing.

Track costs by job: mobilization, drilling per foot, casing and screen, grout, development, pump installation, and testing.

Estimate pricing with unit costs for depth, casing, and grout, plus allowances for lost circulation, difficult formations, and standby time.

Keep equipment maintenance logs and calibration records for meters and test instruments; these support both safety and quality claims.

Retain records for the period required by state rules and by contract; well logs and water quality results may be requested long after completion.

Insurance should cover general liability, pollution/environmental liability, and workers' compensation; drilling work carries both subsurface and chemical exposure risks.

Change orders for unforeseen conditions (lost circulation, boulders, deeper casing) protect both parties and should be signed before the extra work proceeds.