Question 1 — Groundwater rights and stream depletion
A municipal utility proposes a production well in an alluvial aquifer hydraulically connected to a
stream subject to existing senior water rights. An aquifer test indicates that the proposed
withdrawal will eventually reduce groundwater discharge to the stream.
The utility argues that the well is sufficiently far from the stream to avoid affecting existing
water rights.
What is the most appropriate professional conclusion?
A) The distance from the stream establishes that existing water rights cannot be affected.
B) Groundwater withdrawals cannot impair surface-water rights because they involve different
water sources.
C) The potential magnitude and timing of streamflow depletion must be evaluated before
concluding that the proposed withdrawal will not impair existing rights.
D) The proposed withdrawal can be approved on the basis of aquifer transmissivity alone.
Correct Answer: C) The potential magnitude and timing of streamflow depletion must be
evaluated before concluding that the proposed withdrawal will not impair existing rights.
Rationale: Hydraulic connectivity means that pumping can affect surface-water flows even when
a production well is located some distance from a stream. Aquifer properties, pumping rates,
distance and boundary conditions determine the timing and magnitude of depletion.
Washington's groundwater laws require consideration of existing water rights, making a
defensible interference assessment essential to the proposed development.
Blueprint alignment: Professional Practice, Task T2 — Identify water-rights implications from
groundwater information.
Question 2 — Contamination assessment and regulatory obligations
A hydrogeologist is retained to investigate a former industrial property in Washington. Historical
records indicate that chlorinated solvents were stored in underground tanks. Groundwater
samples from a nearby property contain trichloroethylene, but the extent and source of
contamination have not been established.
The property owner asks the hydrogeologist to limit the investigation to the former tank
locations.
Which approach is most defensible?
,A) Develop an investigation that addresses the suspected sources, potential migration pathways,
receptors and applicable cleanup requirements.
B) Restrict sampling to the former tank locations because off-property groundwater conditions
are outside the original scope.
C) Assume that contamination found on the neighboring property originated from the former
underground tanks.
D) Select a remediation technology before determining the extent of contamination.
Correct Answer: A) Develop an investigation that addresses the suspected sources, potential
migration pathways, receptors and applicable cleanup requirements.
Rationale: An appropriate investigation must distinguish suspected contamination sources from
demonstrated sources and characterize relevant migration pathways. Washington's Model Toxics
Control Act cleanup regulations provide the regulatory framework for investigating and cleaning
up contaminated sites. The hydrogeologist should establish an investigation scope that addresses
the applicable requirements without prematurely attributing contamination to a particular source.
Blueprint alignment: Professional Practice, Tasks T1 and T3 — Contamination assessment and
applicable regulations.
Reference:
Chapter 173-340 WAC — Model Toxics Control Act cleanup regulations
.
Question 3 — Water-well construction compliance
A hydrogeologist is reviewing the construction records for a new municipal production well. The
records show that the well penetrates two aquifers separated by a clay confining unit. The
annular seal was not installed across the full interval needed to preserve the separation between
the aquifers.
The drilling contractor states that the well is acceptable because it produces the required quantity
of water.
What is the most appropriate response?
A) Accept the well because production capacity demonstrates that construction requirements
have been satisfied.
B) Evaluate only the well's pumping efficiency, because aquifer separation is unrelated to well
performance.
,C) Increase the pumping rate to determine whether the missing seal affects well yield.
D) Evaluate the construction against Washington's applicable well-construction standards and
determine the corrective measures needed to prevent interaquifer flow.
Correct Answer: D) Evaluate the construction against Washington's applicable well-construction
standards and determine the corrective measures needed to prevent interaquifer flow.
Rationale: Well yield alone does not establish that a production well complies with construction
standards or adequately protects groundwater resources. An improperly sealed annulus may
allow groundwater movement between aquifers, potentially transferring contaminants or altering
hydraulic conditions. Washington's minimum well-construction standards establish applicable
requirements for preventing unwanted hydraulic communication between formations.
Blueprint alignment: Professional Practice, Task T3 — Application of hydrogeology regulations.
Reference:
Chapter 173-160 WAC — Minimum standards for construction and maintenance of wells
.
Question 4 — Public water-supply protection
A public water system obtains drinking water from a confined aquifer. A proposed industrial
development is located within the estimated groundwater capture area of the production well.
The aquifer is overlain by a clay unit, but existing geological records indicate that the clay is
discontinuous.
The developer argues that the aquifer's confined status makes additional groundwater protection
unnecessary.
Which conclusion is most appropriate?
A) Confined aquifers are always protected from contamination originating at the land surface.
B) The potential for contaminant migration should be evaluated using site-specific
hydrostratigraphy, groundwater flow conditions and applicable wellhead protection
requirements.
C) The clay unit can be assumed to prevent all vertical groundwater movement regardless of its
continuity.
D) The capture area is irrelevant because the production well penetrates a confined aquifer.
, Correct Answer: B) The potential for contaminant migration should be evaluated using site-
specific hydrostratigraphy, groundwater flow conditions and applicable wellhead protection
requirements.
Rationale: Confining units can reduce contaminant migration but do not necessarily eliminate it.
Discontinuities, fractures, improperly constructed wells and other preferential pathways may
permit contaminants to reach deeper groundwater systems. A defensible water-supply protection
assessment should consider the capture area, potential contaminant sources, hydraulic conditions
and the applicable requirements for public water supplies.
Blueprint alignment: Professional Practice, Task T3 — Regulatory application, with supporting
concepts from Project Planning, Task T4 — Water-supply protection.
Reference:
Chapter 246-290 WAC — Group A public water supplies
.
Question 5 — Groundwater withdrawal and potential impairment
A hydrogeologist evaluates a proposed groundwater withdrawal near an existing agricultural
production well. Aquifer testing suggests that the proposed withdrawal will produce additional
drawdown at the existing well. However, the available records do not establish whether that
drawdown would prevent the existing well from exercising its authorized water right.
What should the hydrogeologist recommend?
A) Conclude that any measurable drawdown automatically constitutes legal impairment.
B) Conclude that the proposed withdrawal cannot cause impairment because both wells penetrate
the same aquifer.
C) Evaluate the predicted drawdown in relation to the existing well's construction, pumping
conditions and authorized use, and document the remaining uncertainty.
D) Ignore the predicted drawdown unless the existing well has already stopped producing water.
Correct Answer: C) Evaluate the predicted drawdown in relation to the existing well's
construction, pumping conditions and authorized use, and document the remaining uncertainty.
Rationale: Measurable drawdown does not, by itself, establish whether an existing groundwater
right will be impaired. The assessment should consider the affected well's construction, pumping
conditions, available drawdown and relevant regulatory criteria. Washington's groundwater
regulations address the protection of withdrawal facilities, so technical findings must distinguish
predicted hydraulic effects from conclusions requiring additional evidence.
A municipal utility proposes a production well in an alluvial aquifer hydraulically connected to a
stream subject to existing senior water rights. An aquifer test indicates that the proposed
withdrawal will eventually reduce groundwater discharge to the stream.
The utility argues that the well is sufficiently far from the stream to avoid affecting existing
water rights.
What is the most appropriate professional conclusion?
A) The distance from the stream establishes that existing water rights cannot be affected.
B) Groundwater withdrawals cannot impair surface-water rights because they involve different
water sources.
C) The potential magnitude and timing of streamflow depletion must be evaluated before
concluding that the proposed withdrawal will not impair existing rights.
D) The proposed withdrawal can be approved on the basis of aquifer transmissivity alone.
Correct Answer: C) The potential magnitude and timing of streamflow depletion must be
evaluated before concluding that the proposed withdrawal will not impair existing rights.
Rationale: Hydraulic connectivity means that pumping can affect surface-water flows even when
a production well is located some distance from a stream. Aquifer properties, pumping rates,
distance and boundary conditions determine the timing and magnitude of depletion.
Washington's groundwater laws require consideration of existing water rights, making a
defensible interference assessment essential to the proposed development.
Blueprint alignment: Professional Practice, Task T2 — Identify water-rights implications from
groundwater information.
Question 2 — Contamination assessment and regulatory obligations
A hydrogeologist is retained to investigate a former industrial property in Washington. Historical
records indicate that chlorinated solvents were stored in underground tanks. Groundwater
samples from a nearby property contain trichloroethylene, but the extent and source of
contamination have not been established.
The property owner asks the hydrogeologist to limit the investigation to the former tank
locations.
Which approach is most defensible?
,A) Develop an investigation that addresses the suspected sources, potential migration pathways,
receptors and applicable cleanup requirements.
B) Restrict sampling to the former tank locations because off-property groundwater conditions
are outside the original scope.
C) Assume that contamination found on the neighboring property originated from the former
underground tanks.
D) Select a remediation technology before determining the extent of contamination.
Correct Answer: A) Develop an investigation that addresses the suspected sources, potential
migration pathways, receptors and applicable cleanup requirements.
Rationale: An appropriate investigation must distinguish suspected contamination sources from
demonstrated sources and characterize relevant migration pathways. Washington's Model Toxics
Control Act cleanup regulations provide the regulatory framework for investigating and cleaning
up contaminated sites. The hydrogeologist should establish an investigation scope that addresses
the applicable requirements without prematurely attributing contamination to a particular source.
Blueprint alignment: Professional Practice, Tasks T1 and T3 — Contamination assessment and
applicable regulations.
Reference:
Chapter 173-340 WAC — Model Toxics Control Act cleanup regulations
.
Question 3 — Water-well construction compliance
A hydrogeologist is reviewing the construction records for a new municipal production well. The
records show that the well penetrates two aquifers separated by a clay confining unit. The
annular seal was not installed across the full interval needed to preserve the separation between
the aquifers.
The drilling contractor states that the well is acceptable because it produces the required quantity
of water.
What is the most appropriate response?
A) Accept the well because production capacity demonstrates that construction requirements
have been satisfied.
B) Evaluate only the well's pumping efficiency, because aquifer separation is unrelated to well
performance.
,C) Increase the pumping rate to determine whether the missing seal affects well yield.
D) Evaluate the construction against Washington's applicable well-construction standards and
determine the corrective measures needed to prevent interaquifer flow.
Correct Answer: D) Evaluate the construction against Washington's applicable well-construction
standards and determine the corrective measures needed to prevent interaquifer flow.
Rationale: Well yield alone does not establish that a production well complies with construction
standards or adequately protects groundwater resources. An improperly sealed annulus may
allow groundwater movement between aquifers, potentially transferring contaminants or altering
hydraulic conditions. Washington's minimum well-construction standards establish applicable
requirements for preventing unwanted hydraulic communication between formations.
Blueprint alignment: Professional Practice, Task T3 — Application of hydrogeology regulations.
Reference:
Chapter 173-160 WAC — Minimum standards for construction and maintenance of wells
.
Question 4 — Public water-supply protection
A public water system obtains drinking water from a confined aquifer. A proposed industrial
development is located within the estimated groundwater capture area of the production well.
The aquifer is overlain by a clay unit, but existing geological records indicate that the clay is
discontinuous.
The developer argues that the aquifer's confined status makes additional groundwater protection
unnecessary.
Which conclusion is most appropriate?
A) Confined aquifers are always protected from contamination originating at the land surface.
B) The potential for contaminant migration should be evaluated using site-specific
hydrostratigraphy, groundwater flow conditions and applicable wellhead protection
requirements.
C) The clay unit can be assumed to prevent all vertical groundwater movement regardless of its
continuity.
D) The capture area is irrelevant because the production well penetrates a confined aquifer.
, Correct Answer: B) The potential for contaminant migration should be evaluated using site-
specific hydrostratigraphy, groundwater flow conditions and applicable wellhead protection
requirements.
Rationale: Confining units can reduce contaminant migration but do not necessarily eliminate it.
Discontinuities, fractures, improperly constructed wells and other preferential pathways may
permit contaminants to reach deeper groundwater systems. A defensible water-supply protection
assessment should consider the capture area, potential contaminant sources, hydraulic conditions
and the applicable requirements for public water supplies.
Blueprint alignment: Professional Practice, Task T3 — Regulatory application, with supporting
concepts from Project Planning, Task T4 — Water-supply protection.
Reference:
Chapter 246-290 WAC — Group A public water supplies
.
Question 5 — Groundwater withdrawal and potential impairment
A hydrogeologist evaluates a proposed groundwater withdrawal near an existing agricultural
production well. Aquifer testing suggests that the proposed withdrawal will produce additional
drawdown at the existing well. However, the available records do not establish whether that
drawdown would prevent the existing well from exercising its authorized water right.
What should the hydrogeologist recommend?
A) Conclude that any measurable drawdown automatically constitutes legal impairment.
B) Conclude that the proposed withdrawal cannot cause impairment because both wells penetrate
the same aquifer.
C) Evaluate the predicted drawdown in relation to the existing well's construction, pumping
conditions and authorized use, and document the remaining uncertainty.
D) Ignore the predicted drawdown unless the existing well has already stopped producing water.
Correct Answer: C) Evaluate the predicted drawdown in relation to the existing well's
construction, pumping conditions and authorized use, and document the remaining uncertainty.
Rationale: Measurable drawdown does not, by itself, establish whether an existing groundwater
right will be impaired. The assessment should consider the affected well's construction, pumping
conditions, available drawdown and relevant regulatory criteria. Washington's groundwater
regulations address the protection of withdrawal facilities, so technical findings must distinguish
predicted hydraulic effects from conclusions requiring additional evidence.
