NV Well Driller flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Minimum annular seal depth

Nevada requires at least 20 feet of neat cement or bentonite grout in the annular space, extending from land surface or top of casing downward, and deeper if needed to seal off unconfined aquifers or poor-quality water.

Casing height above ground

Well casing must extend at least 12 inches above land surface or above the concrete pad, and the pad must be at least 4 inches thick and slope away from the casing to prevent contamination.

Grout placement method

Grout must be placed by the pump-and-tremie method from the bottom up; free-fall dumping is prohibited because it can bridge and leave voids, compromising the seal.

Septic tank isolation distance

A well must be at least 50 feet from a septic tank, 100 feet from a septic drainfield, 100 feet from a feedlot, and 200 feet from a sanitary landfill or hazardous waste site, unless local ordinance requires greater distances.

Screen opening size selection

Well screen openings should be sized to retain 90% of the formation sand (D90) to prevent sand production while allowing adequate water flow into the well.

Well development purpose

Development removes drilling mud, fines, and debris from the borehole and screen, improving yield and water clarity; it continues until discharge water is clear and sand-free.

Abandoned well sealing

Abandoned wells must be filled with grout or approved sealing material, with the upper 20 feet sealed with neat cement, and the work documented on the appropriate Division form.

Prior appropriation doctrine

Nevada water law follows prior appropriation: the first person to put water to beneficial use obtains the right, and in times of shortage, senior rights are satisfied before junior rights.

State Engineer authority

The Nevada State Engineer administers water rights, issues permits for new appropriations, adjudicates conflicts, and regulates well drilling through the Office of the State Engineer.

Notice of Intent to Drill

Before drilling, a licensed well driller must file a Notice of Intent to Drill with the State Engineer, providing the proposed well location, depth, and intended use.

Domestic well exemption limit

Domestic wells are exempt from obtaining a water right permit only for uses of less than 1,800 gallons per day (0.0056 cfs) for household purposes; larger uses require a permit.

Designated groundwater basin

A groundwater basin designated by the State Engineer where preferred uses are established and new appropriations may be limited or denied based on available water supply.

Water right priority date

The priority date determines the order in which water rights are satisfied during shortage; earlier priority dates have seniority over later ones under prior appropriation.

Well Driller's Report deadline

A Well Driller's Report (Form 3) must be submitted to the State Engineer within 30 days after completion of drilling, modification, or abandonment of a well.

Required well log content

The well log must include owner information, well location, drilling method, total depth, casing diameter and depth, screen intervals, static water level, yield test data, and grout volume and method.

Well log retention period

The well driller must provide a copy of the well log to the well owner and retain a copy for at least 5 years for recordkeeping and potential inspection.

Lithologic log description

Drillers must record formations encountered using standard terms such as sand, gravel, clay, sandstone, or limestone, and note the depth of each change in the well log.

Abandonment report requirements

The abandonment report must document the sealing method and materials, including grout type, volume, and depth of seal, and be filed with the State Engineer on the appropriate form.

Consequence of incomplete log

Failure to file a complete and accurate well log is a violation that may result in a fine or license action; the well log is a public record maintained by the State Engineer.

Darcy's Law formula

Q = K * i * A, where Q is discharge (ft³/day), K is hydraulic conductivity (ft/day), i is hydraulic gradient (ft/ft), and A is cross-sectional area (ft²).

Transmissivity definition

Transmissivity (T) equals hydraulic conductivity (K) multiplied by saturated thickness (b); it indicates the aquifer's ability to transmit water and is derived from pump test analysis.

Specific yield

Specific yield (Sy) is the volume of water released from storage per unit volume of aquifer; unconfined aquifers have significant Sy, while confined aquifers have much smaller storativity.

Drawdown calculation

Drawdown (s) is the difference between the pumping water level and the static water level; it is measured during a pump test to evaluate well performance and aquifer properties.

Theis method use

The Theis method analyzes pump test data by matching drawdown versus time curves to type curves, yielding transmissivity and storativity for the aquifer.

Cooper-Jacob straight-line method

A pump test analysis method that plots drawdown versus log of time; the straight-line portion yields transmissivity from the slope and storativity from the intercept.

Static water level

The level of water in a well when it is not pumping, representing the natural hydraulic head of the aquifer at that location.

Pumping water level

The water level in a well during pumping, which is lower than the static level due to drawdown caused by extraction and aquifer response.

Site evaluation contamination sources

A site evaluation must identify potential contamination sources within required isolation distances, such as septic systems, fuel tanks, chemical storage, and animal waste.

Aquifer boundary effects

Faults and impermeable layers can affect well yield and water quality; a well near a fault may have higher yield but increased risk of contamination or connection to poor-quality water.

Well yield estimate

Well yield is estimated by pump test or bailer test; a minimum yield of 2-5 gpm is often required for a domestic well, but local requirements vary.

Hydraulic gradient

The change in hydraulic head per unit distance (ft/ft) that drives groundwater flow from areas of higher head to lower head.

Beneficial use concept

Under Nevada water law, beneficial use is the basis, measure, and limit of a water right; water must be put to a reasonable and useful purpose without waste.