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ME Well Driller practice questions

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Question 1Well Construction and Siting

Under the Maine well driller rules, what is the minimum required separation between a new drilled well and a subsurface wastewater disposal (septic) system?

  1. 25 feet
  2. 50 feet Correct answer.
  3. 100 feet
  4. 75 feet

Explanation

Maine's well siting rules require a minimum 50-foot horizontal separation between a well and any subsurface wastewater disposal system to reduce the risk of bacteriological and nitrate contamination. Larger separations may be required where site conditions or local ordinances demand it.

Question 2Well Construction and Siting

A well driller is siting a new well on a lot where the property line is close to the proposed location. What is the standard minimum setback from a property line for a drilled well in Maine?

  1. 10 feet Correct answer.
  2. 50 feet
  3. 20 feet
  4. 30 feet

Explanation

The standard minimum setback from a property line for a well is 10 feet, which protects neighboring property and reduces disputes over shared aquifer use. Local ordinances may impose a larger setback, so the driller should always check municipal requirements.

Question 3Well Construction and Siting

Why must a drilled well be cased and grouted from the surface down through the overburden?

  1. To allow the well to be used as a monitoring well
  2. To reduce the cost of the well construction
  3. To increase the pumping rate of the well
  4. To prevent surface water and shallow groundwater from entering the well bore Correct answer.

Explanation

Casing and grouting form a sanitary seal that blocks surface runoff and shallow, potentially contaminated groundwater from migrating down the borehole into the producing aquifer. This seal is a core public-health protection in well construction.

Question 4Well Construction and Siting

What is the primary purpose of a well cap on a drilled well?

  1. To increase the pressure in the water system
  2. To anchor the pump in the well
  3. To filter sediment from the produced water
  4. To keep out insects, surface water, and debris while allowing access for service Correct answer.

Explanation

A properly fitted, vermin-proof well cap seals the top of the casing against insects, surface water, and debris while remaining removable for service and inspection. It is a sanitary protection component, not a pressure or filtration device.

Question 5Well Construction and Siting

Which type of well is typically completed by driving a casing with a drive shoe and screen into unconsolidated sand and gravel?

  1. Bedrock (artesian) well
  2. Dug well
  3. Driven point (sand point) well Correct answer.
  4. Rock-bored well

Explanation

A driven point well uses a pointed screen and casing driven into shallow unconsolidated sand and gravel to draw water from the surrounding formation. It is limited to shallow depths and suitable loose materials.

Question 6Well Construction and Siting

What is the purpose of a pitless adapter in a drilled well installation?

  1. To provide a backup power source for the pump
  2. To filter iron and manganese from the water
  3. To increase the well's yield
  4. To allow the water line to exit the casing below the frost line while keeping the wellhead sealed Correct answer.

Explanation

A pitless adapter lets the service line pass through the casing wall below frost depth and connects to the drop pipe, so no pit is needed and the wellhead remains sanitary and freeze-protected. It does not affect yield or water treatment.

Question 7Well Construction and Siting

Which of the following is the best evidence that a proposed well location may be affected by nearby contamination?

  1. The site is far from any roads
  2. The site has a thick layer of clay at the surface
  3. The site is on a ridge above the surrounding terrain
  4. The site is downslope from a septic system and a fuel storage tank Correct answer.

Explanation

Being downslope from a septic system and a fuel tank places the well in the likely path of groundwater flow from those contamination sources. Topographic position and proximity to potential sources are central to siting analysis.

Question 8Well Construction and Siting

What does the static water level in a well represent?

  1. The level of water in the well when the pump is not running and the water has stabilized Correct answer.
  2. The depth of the well screen
  3. The maximum pumping rate the well can sustain
  4. The depth at which the pump is set

Explanation

Static water level is the stabilized water level measured when the well is at rest, reflecting the natural piezometric head of the aquifer. It is used to calculate drawdown and pump setting depth.

Question 9Well Construction and Siting

A driller observes that the water level in a well drops significantly while the pump is running and recovers slowly after shutoff. What does this most likely indicate?

  1. The well has a high specific capacity
  2. The casing is oversized
  3. The pump is set too shallow
  4. The well is drawing down more than the aquifer can readily recharge at that pumping rate Correct answer.

Explanation

Large drawdown with slow recovery indicates the pumping rate exceeds the aquifer's ability to supply water to the well, or that the formation has low transmissivity. Reducing the pumping rate or improving the well may be needed.

Question 10Well Construction and Siting

During a pumping test, a well produces 15 gallons per minute with a drawdown of 5 feet. What is the specific capacity of the well?

  1. 75 gpm per foot
  2. 3 gpm per foot Correct answer.
  3. 0.33 gpm per foot
  4. 10 gpm per foot

Explanation

Specific capacity is the pumping rate divided by drawdown: 15 gpm ÷ 5 ft = 3 gpm per foot. It expresses how much water the well yields per foot of water-level decline and is used to compare well performance.

Question 11Well Construction and Siting

Why is a bentonite grout seal preferred over a sand or gravel seal in the annular space above the screen?

  1. Bentonite is cheaper than any other material
  2. Bentonite dissolves slowly to feed the aquifer
  3. Bentonite increases the well yield
  4. Bentonite expands when hydrated and forms a low-permeability barrier Correct answer.

Explanation

Hydrated bentonite swells and creates a dense, low-permeability seal that prevents vertical migration of water and contaminants along the annulus. This is why it is used for sanitary seals and grouting.

Question 12Well Construction and Siting

A driller is completing a well in fractured bedrock. What is the most important factor in locating the well to achieve adequate yield?

  1. The color of the bedrock
  2. The depth of the overburden
  3. The diameter of the casing
  4. The presence and orientation of water-bearing fractures and lineaments Correct answer.

Explanation

In bedrock, water is stored and transmitted mainly through fractures, so identifying fracture zones and lineaments greatly improves the chance of a productive well. Overburden depth and casing size matter less than intersecting transmissive fractures.

Question 13Well Construction and Siting

What is the primary reason for developing a new well after drilling?

  1. To sterilize the well permanently
  2. To lower the static water level
  3. To increase the casing diameter
  4. To remove drilling fines and improve the connection between the well and the aquifer Correct answer.

Explanation

Well development removes drilling mud, cuttings, and fines from the screen and surrounding formation, improving hydraulic connection and yield. It also helps stabilize the formation around the intake.

Question 14Well Construction and Siting

A driller is installing a submersible pump in a well with a static water level of 40 feet and a pumping water level of 60 feet. Where should the pump intake be set to avoid running dry?

  1. At the very bottom of the well
  2. Above the static water level at 30 feet
  3. Below the pumping water level with adequate submergence, such as 70 to 80 feet Correct answer.
  4. Just below the static water level at 45 feet

Explanation

The pump should be set below the pumping water level so it remains submerged during operation, with enough clearance above the well bottom. Setting it at or above the static level risks the pump breaking suction and running dry.

Question 15Well Construction and Siting

What does a well log (driller's log) primarily record?

  1. The cost of the well
  2. The geologic materials encountered, depths, water-bearing zones, and construction details Correct answer.
  3. The daily weather conditions during drilling
  4. The customer's water-use habits

Explanation

A driller's log documents the stratigraphy, depth of water strikes, casing and screen intervals, and grouting details, providing a permanent record for future service and regulatory review. It is a technical construction record.

Question 16Well Construction and Siting

Which practice best protects a well during construction from contamination by surface water?

  1. Storing fuel and oil next to the wellhead
  2. Maintaining a temporary seal or cap on the casing and grading the site to drain away from the well Correct answer.
  3. Washing tools in the well bore
  4. Leaving the casing open overnight during drilling

Explanation

Keeping the casing sealed when work stops and grading the surface to divert runoff protects the borehole from surface contamination during construction. Good housekeeping around the wellhead further reduces risk.

Question 17Well Construction and Siting

Why is it important to verify that a proposed well location is not within a designated wellhead protection area for a public water system?

  1. Because drilling is faster in these areas
  2. Because activities in these areas are regulated to protect the public supply from contamination Correct answer.
  3. Because new wells are prohibited by law in all areas
  4. Because the water is always deeper in these areas

Explanation

Wellhead protection areas are delineated around public supply wells to manage land uses that could contaminate the source. A new well may be restricted or require review because of the potential to introduce contamination or interfere with the public supply.

Question 18Well Construction and Siting

A well is drilled to 300 feet with casing to 60 feet and an open borehole below. The driller wants to grout the annulus. What is the most appropriate method?

  1. Pump grout through a tremie pipe from the bottom of the annular space upward Correct answer.
  2. Leave the annulus open to allow groundwater to drain
  3. Backfill with drill cuttings
  4. Pour dry bentonite chips from the surface without measuring the volume

Explanation

Tremie grouting places grout at the bottom of the annulus and displaces it upward, ensuring a continuous seal without voids or bridging. Surface pouring and backfilling with cuttings do not reliably seal the annular space.

Question 19Well Construction and Siting

What is the main purpose of a well screen in a sand and gravel well?

  1. To seal the well from surface water
  2. To support the pump
  3. To hold back formation material while allowing water to enter the well Correct answer.
  4. To increase the static water level

Explanation

The screen retains sand and gravel while admitting water, and its slot size is matched to the formation gradation. It prevents sediment from entering the well and damaging the pump.

Question 20Well Construction and Siting

A driller is evaluating a site where the water table is shallow and the soil is sandy. Which design consideration is most important for preventing contamination?

  1. Increasing the casing diameter
  2. Extending the casing and grout seal to a sufficient depth and properly sealing the wellhead Correct answer.
  3. Drilling deeper than necessary
  4. Using a larger pump

Explanation

Shallow sandy sites are vulnerable to rapid downward movement of surface water, so a deep, continuous casing and grout seal with a sanitary wellhead is critical. Casing diameter and pump size do not address contamination pathways.

Question 21Well Construction and Siting

What is the purpose of a yield test on a newly completed well?

  1. To test the electrical wiring of the pump
  2. To determine the sustainable pumping rate and the associated drawdown Correct answer.
  3. To measure the depth of the well
  4. To confirm the casing is the correct color

Explanation

A yield test measures the well's response to pumping, including the pumping rate, drawdown, and recovery, to establish a sustainable operating rate. It is a performance evaluation of the well and aquifer.

Question 22Well Construction and Siting

A driller encounters a large void or cavern in limestone during drilling. What is the most significant risk to well construction?

  1. The well log may be too short
  2. The pump may run too slowly
  3. Loss of drilling fluid, collapse of the borehole, and uncontrolled water flow Correct answer.
  4. The casing may become too warm

Explanation

Solution cavities in limestone can cause sudden loss of circulation, borehole collapse, and unpredictable water flow, complicating drilling and completion. The driller must address these conditions before finalizing the well design.

Question 23Well Construction and Siting

A well is located 80 feet from a septic system and 15 feet from a property line. Which statement best describes the regulatory status of this siting?

  1. It meets the wastewater setback but violates the property-line setback Correct answer.
  2. It violates both setbacks
  3. It violates the wastewater setback but meets the property-line setback
  4. It meets both the wastewater and property-line setbacks

Explanation

The 80-foot distance exceeds the 50-foot wastewater separation, but the 15-foot distance is less than the 10-foot minimum required from a property line. The property-line violation means the siting does not comply.

Question 24Well Construction and Siting

During a pumping test, drawdown measurements show that the water level continues to decline steadily without stabilizing after several hours. What is the most likely interpretation?

  1. The well has reached steady-state conditions
  2. The pump is operating below its rated capacity
  3. The static water level has risen
  4. The pumping rate exceeds the sustainable yield or there is a boundary effect such as recharge limitation Correct answer.

Explanation

Continued decline without stabilization suggests the aquifer cannot sustain the pumping rate or that a low-permeability boundary limits recharge. The driller should reduce the rate or investigate the hydrogeologic setting.

Question 25Well Construction and Siting

A driller plans to grout the annulus of a well completed in a confined aquifer. Why must the grout seal extend above the confining layer and to the surface?

  1. To allow surface water to recharge the aquifer
  2. To prevent the confined aquifer from flowing uncontrolled and to block vertical migration between aquifers Correct answer.
  3. To increase the artesian pressure
  4. To reduce the depth of the well

Explanation

A continuous seal above the confining unit prevents the confined aquifer from leaking along the annulus and stops cross-contamination between water-bearing zones. It also controls artesian flow at the surface.

Question 26Well Construction and Siting

Before drilling, a well contractor must obtain which document that establishes the legal right to use groundwater at the site?

  1. A bill of sale for the drilling equipment
  2. A water well permit or approval issued by the state or local regulatory authority Correct answer.
  3. A site plan approved by the local planning board
  4. A warranty deed recorded with the county registry of deeds

Explanation

Groundwater use is regulated at the state or local level, and a well permit or similar approval authorizes construction and withdrawal. A deed transfers real property but does not authorize water use, and planning or equipment documents have no bearing on water rights.

Question 27Well Construction and Siting

Which setback is most commonly required between a new private well and a septic tank or leach field under state well construction rules?

  1. No separation, provided the well casing is grouted
  2. A separation equal to the depth of the well
  3. A minimum separation distance, often 50 feet or more, specified in state code Correct answer.
  4. A separation of only 5 feet measured from the well cap

Explanation

State well codes typically require a specified minimum horizontal separation between a well and sources of contamination such as septic systems, commonly 50 feet or more. Grouting protects the annulus but does not replace the required setback distance.

Question 28Well Construction and Siting

What does the term 'zone of influence' describe in the context of a pumping well?

  1. The interval of the borehole that contains the well screen
  2. The area around the well where pumping measurably lowers the water table or potentiometric surface Correct answer.
  3. The vertical distance between the land surface and the top of the casing
  4. The region of the aquifer that contains no recoverable water

Explanation

The zone of influence is the areal extent over which drawdown from a pumping well can be detected. It is a response of the aquifer to pumping, not a physical part of the well construction.

Question 29Well Construction and Siting

Why is a topographic map useful when selecting a well site on a hillside?

  1. It indicates the yield of nearby wells
  2. It identifies the exact depth to bedrock at the site
  3. It shows the chemical quality of the groundwater
  4. It shows slope and drainage direction, helping the driller avoid placing the well below contaminant sources Correct answer.

Explanation

Contours reveal slope and the direction surface water drains, which helps keep a well upslope of septic systems, barnyards, and other contamination sources. Topographic maps do not provide subsurface geology, water chemistry, or well yields.

Question 30Well Construction and Siting

What is the purpose of a sanitary well cap on a completed well?

  1. To vent dissolved gases from the aquifer
  2. To support the weight of the pump and drop pipe
  3. To measure the static water level in the well
  4. To seal the top of the casing against the entry of surface water, insects, and debris Correct answer.

Explanation

A sanitary cap provides a vermin-proof, watertight seal at the top of the casing while allowing access for service. It is not a structural support for the pump assembly or a measuring device.

Question 31Well Construction and Siting

A driller is siting a well on a lot where the only practical location is within 25 feet of a barnyard used for livestock. What is the most appropriate action?

  1. Proceed because the well cap will keep animals out of the casing
  2. Relocate the well to meet the required separation from the livestock area or obtain approval for an alternative design Correct answer.
  3. Proceed and increase the grout depth to compensate for the close spacing
  4. Proceed because livestock waste is not considered a contamination source

Explanation

Livestock areas are recognized contamination sources, and state codes set minimum separations from them. Where the setback cannot be met, the driller should relocate the well or seek regulatory approval for an approved alternative rather than rely on construction details alone.

Question 32Well Construction and Siting

Which of the following is a primary purpose of a preliminary site assessment before drilling a new well?

  1. To determine the final pump horsepower needed for the installation
  2. To establish the grout volume required for the annulus
  3. To calculate the exact specific capacity of the completed well
  4. To identify potential contamination sources and confirm that required setbacks can be met Correct answer.

Explanation

A preliminary assessment surveys the site for contamination sources, property lines, and setbacks before the rig is moved. Pump sizing, specific capacity, and grout volume are determined later from test data and construction dimensions.

Question 33Well Construction and Siting

Which statement best describes the role of a property line in well siting?

  1. State codes commonly require a minimum setback from property lines to protect neighboring land and water rights Correct answer.
  2. Setbacks from property lines apply only to public water supply wells
  3. Property lines have no bearing on well location once a permit is issued
  4. A well may be placed directly on a property line if both owners agree verbally

Explanation

Well codes typically specify a minimum distance from property lines so that drawdown and construction do not adversely affect neighboring parcels. Verbal agreements do not override the codified setback.

Question 34Well Construction and Siting

A driller is choosing between a site in a low swale and a site on a gentle rise 60 feet away, both on the same property and both meeting setbacks. Which choice is preferable and why?

  1. The swale, because the surrounding soil filters runoff before it reaches the well
  2. The swale, because shallow groundwater is closer to the surface and easier to reach
  3. The rise, because surface water drains away from the wellhead rather than ponding around the casing Correct answer.
  4. Either site, because the sanitary cap makes surface drainage irrelevant

Explanation

Siting on higher ground that drains away from the wellhead reduces the chance of ponded surface water entering the annular space or casing. A low swale concentrates runoff at the well, increasing contamination risk regardless of cap design.

Question 35Well Construction and Siting

A driller plans a well on a lot where a nearby abandoned hand-dug well is visible. What is the most appropriate siting response?

  1. Place the new well as close as possible to the old one to tap the same water-bearing zone
  2. Ignore the old well because it predates current regulations
  3. Fill the old well with gravel and drill immediately adjacent to it
  4. Treat the old well as a potential contamination pathway and maintain the required separation or properly abandon it before proceeding Correct answer.

Explanation

An unsealed old well can funnel surface water and contaminants directly into the aquifer, so it must be considered in siting and separation decisions. Proper abandonment under state rules removes the pathway and may allow the new well to be placed appropriately.

Question 36Well Construction and Siting

Which investigation method provides the most direct information about the depth and thickness of water-bearing formations before a well is drilled?

  1. An inspection of the well cap on a neighboring well
  2. A test boring or exploratory hole logged by the driller Correct answer.
  3. An interview with the property owner about lawn watering habits
  4. A review of the county road map

Explanation

An exploratory boring or test hole allows the driller to observe and log the actual materials and saturated zones at the site. Maps, interviews, and surface inspections provide indirect or unrelated information.

Question 37Well Construction and Siting

A driller is siting a well in an area underlain by karst limestone. Which siting concern is most significant?

  1. Difficulty in obtaining a permit from the local health department
  2. Low static water levels during the summer months
  3. Excessive groundwater hardness requiring a water softener
  4. Rapid movement of surface contaminants through solution openings with little natural filtration Correct answer.

Explanation

Karst aquifers transmit water rapidly through solution channels, so contaminants can travel long distances with minimal filtration. Siting must emphasize separation from contamination sources and careful annular sealing.

Question 38Well Construction and Siting

A well is proposed on a lot that slopes steeply toward the wellhead from an upgradient neighbor's septic system. What is the most appropriate siting conclusion?

  1. The site is acceptable if the casing is extended 2 feet above grade
  2. The site is acceptable because the septic system is on another parcel
  3. The site is unfavorable because subsurface flow follows the slope toward the well, so an alternative location should be evaluated Correct answer.
  4. The site is acceptable because gravity carries contaminants away from the well

Explanation

Where the land slopes toward the proposed wellhead from an upgradient contamination source, both surface and shallow subsurface flow can move toward the well. Property boundaries do not shield a well from contaminants, so an alternative location should be considered.

Question 39Well Construction and Siting

What is the primary reason state codes require the well casing to extend a minimum height above the finished grade?

  1. To reduce the cost of the pump installation
  2. To make the well easier to locate with a metal detector
  3. To increase the storage volume of the pressure tank
  4. To keep the wellhead above floodwater, snow, and surface runoff that could enter the casing Correct answer.

Explanation

Extending the casing above grade keeps the wellhead above likely surface water and snow accumulation, reducing the chance of contamination entering the well. Height above grade has no relationship to tank storage or pump cost.

Question 40Well Construction and Siting

A driller is evaluating two candidate sites on the same parcel. Site A is 100 feet from a seasonal stream; Site B is 30 feet from the same stream. Both meet the minimum setback in the state code. Which statement best justifies the final choice?

  1. Site B is preferable because proximity to the stream guarantees a shallow, productive aquifer
  2. Site A is preferable because greater separation from surface water reduces the risk of contamination and flooding Correct answer.
  3. Site B is preferable because the stream will recharge the well more quickly
  4. Either site is equally acceptable because both meet the minimum setback

Explanation

Meeting the minimum setback makes a site legal, but greater separation from surface water generally lowers contamination and flood risk. Professional judgment favors the more protective location when both are otherwise permissible.

Question 41Well Construction and Siting

Which of the following best describes how a driller should use state well records for neighboring properties during siting?

  1. Copy the neighboring well design exactly without modification
  2. Rely on the records to establish the property boundary
  3. Review logged depths, yields, and water levels to anticipate subsurface conditions and required casing depths Correct answer.
  4. Use the records to bypass the need for a site visit

Explanation

Neighboring well records give the driller advance information on expected geology, productive zones, and casing requirements. They supplement, but do not replace, a site visit and site-specific design.

Question 42Well Construction and Siting

A driller finds that the proposed well location lies within a mapped floodplain. What is the most appropriate siting consideration?

  1. Floodplain location is ideal because the aquifer is always shallow there
  2. The well may proceed unchanged because floodwater is naturally filtered by soil
  3. The wellhead should be protected from inundation, or the well relocated, because floodwater can carry contaminants into the well Correct answer.
  4. The well should be drilled deeper to avoid floodwater entirely

Explanation

Floodwater commonly carries bacteria, sediment, and chemicals, and an inundated wellhead can allow contaminated water to enter the casing. Codes often require the casing to be extended above the flood level or the well to be relocated.

Question 43Well Construction and Siting

During siting, a driller notes an old cistern, a dry stock pond, and a buried fuel tank on the proposed lot. Which combination represents the greatest concern for well placement?

  1. The cistern alone, because it is the largest structure
  2. The buried fuel tank and old cistern, because both can channel or release contaminants near the well Correct answer.
  3. None of these, because all are abandoned features
  4. The dry stock pond alone, because it holds no water

Explanation

A buried fuel tank is a direct chemical source, and an old cistern can act as a preferential pathway for surface water and contaminants. Abandoned features still pose risks and must be evaluated before siting.

Question 44Well Construction and Siting

A driller is asked to place a well in a location that satisfies all state setbacks but sits in a depression where runoff collects. Which action best reflects sound professional practice?

  1. Recommend an alternative location or site drainage improvements so runoff does not pond at the wellhead Correct answer.
  2. Install a taller casing and ignore the ponding
  3. Drill at the specified location because the setbacks are met
  4. Reduce the grout depth to allow drainage into the annulus

Explanation

Meeting setbacks is necessary but not sufficient; a wellhead that collects runoff remains vulnerable to contamination. Good practice is to relocate the well or regrade and drain the area so water moves away from the casing.

Question 45Well Construction and Siting

Which factor is most important when deciding whether a proposed well site can reliably supply a household in a low-yield fractured bedrock setting?

  1. The color of the overburden soil at the surface
  2. The size of the pressure tank selected for the system
  3. The presence and orientation of intersecting fracture sets that store and transmit water Correct answer.
  4. The distance from the house to the nearest paved road

Explanation

In fractured bedrock, groundwater is stored and transmitted mainly through fractures, so intersecting fracture zones are the key to a productive well. Surface soil color, road distance, and tank size do not determine bedrock yield.

Question 46Well Construction and Siting

A driller must site a well on a parcel where the only compliant location is under the drip line of a large tree. What is the most defensible professional decision?

  1. Proceed because the drip line is irrelevant to well construction
  2. Evaluate root interference and consider relocating the well or removing the tree, since roots can damage casing and grout Correct answer.
  3. Proceed because tree roots improve the sealing of the annulus
  4. Proceed and reduce the casing depth to avoid the roots

Explanation

Roots can penetrate, deform, or crack casing and disrupt the annular seal over time, creating contamination pathways. The driller should assess the interference and choose a location or measure that protects the well's integrity.

Question 47Well Construction and Siting

A driller is siting a well on a property where the water table is shallow and the soil is predominantly sand. Which combination of concerns should drive the final location and design?

  1. Contamination from surface sources and potential for the wellhead to be affected by a rising water table Correct answer.
  2. Depth to bedrock and the cost of casing
  3. Excessive pump horsepower and oversized pressure tanks
  4. The color of the well cap and the height of the pump house

Explanation

A shallow water table in sandy soil allows rapid downward movement of surface contaminants and can rise to affect the wellhead. Siting should maximize separation from contamination sources and ensure the casing and seal are appropriate for the conditions.

Question 48Well Construction and Siting

A driller is comparing a site on a floodplain terrace with a site 200 feet upslope on till. Both meet setbacks from known sources. Which reasoning best supports selecting the upslope site?

  1. The upslope site is always more productive because higher elevation means more recharge
  2. The floodplain site is preferable because the water table is closer to the surface
  3. The upslope site reduces flood and surface-water contamination risk, though it may require deeper drilling to reach a reliable aquifer Correct answer.
  4. The floodplain site is preferable because till has no permeability

Explanation

Upslope siting on till lowers exposure to flooding and surface contamination but may mean drilling deeper to reach adequate saturated thickness. Higher elevation does not by itself guarantee greater productivity.

Question 49Well Construction and Siting

A driller discovers that a proposed well location is 40 feet from a neighbor's unsealed, unused dug well that is not yet abandoned under state rules. Which action is most appropriate?

  1. Proceed and grout only the new well's annulus
  2. Proceed because the old well is unused
  3. Proceed because the old well is on the neighbor's property
  4. Evaluate the old well as a contamination pathway and coordinate with the owner and regulator to abandon it properly or adjust the location Correct answer.

Explanation

An unsealed dug well can convey surface contaminants into the shared aquifer, so its proximity is a legitimate siting concern even across a property line. Coordinating proper abandonment or relocating the new well addresses the pathway directly.

Question 50Well Construction and Siting

Which siting practice best reduces the chance that a new well will interfere with a neighboring well's water supply?

  1. Drilling as close as possible to the property line to maximize yield
  2. Maintaining adequate spacing between wells and evaluating drawdown effects on nearby wells Correct answer.
  3. Increasing the pump size to draw water away from the neighbor
  4. Installing a larger pressure tank to store more water

Explanation

Wells that are too close can interfere through overlapping cones of depression, especially in low-transmissivity formations. Adequate spacing and evaluation of drawdown effects protect both supplies.