, Question 1
A Walmart distribution center's industrial stormwater permit requires quarterly
sampling for total suspended solids (TSS) and zinc. The facility's SWPPP
specifies a benchmark of 100 mg/L for TSS. During a recent storm event, the
sample result was 150 mg/L. According to EPA's 2021 MSGP, what is the most
appropriate immediate action?
A. Report the exceedance to the state regulatory agency within 24 hours
and implement additional BMPs.
B. Conduct a follow-up sampling event within 30 days to confirm the
exceedance.
C. Document the exceedance in the SWPPP and review BMP
effectiveness during the next annual inspection.
D. Recalculate the benchmark using the facility's long-term average and
adjust the SWPPP accordingly.
Correct Answer: B - Conduct a follow-up sampling event within
30 days to confirm the exceedance.
RATIONALE
Under the 2021 MSGP, if a benchmark is exceeded, the facility must
conduct follow-up sampling within 30 days and review BMPs.
Immediate reporting is only required for exceedances of numeric
effluent limits, not benchmarks. Annual review is insufficient, and
recalculating benchmarks is not allowed.
Question 2
In designing a bioretention cell for a Walmart parking lot in a region with
clayey soils, which modification is most critical to ensure long-term infiltration
performance?
A. Increasing the depth of the ponding area to 12 inches.
B. Incorporating an underdrain system with a sand layer.
C. Planting only native grasses with deep taproots.
Page 2
, D. Adding a geotextile liner at the bottom.
Correct Answer: B - Incorporating an underdrain system with a
sand layer.
RATIONALE
Clayey soils have low infiltration rates; an underdrain with a sand
layer ensures proper drainage and prevents prolonged ponding.
Increasing ponding depth can lead to mosquito breeding and safety
issues. Deep-rooted plants help but cannot overcome low
permeability. A liner would prevent infiltration, defeating the purpose.
Question 3
A Walmart supercenter is undergoing a 5-acre expansion. The construction
stormwater permit requires a SWPPP. Which element is NOT required in the
SWPPP under the 2022 Construction General Permit (CGP)?
A. A site map showing drainage patterns and locations of BMPs.
B. A description of the timing of major grading activities.
C. A detailed list of all subcontractors and their contact information.
D. A maintenance schedule for all BMPs.
Correct Answer: C - A detailed list of all subcontractors and their
contact information.
RATIONALE
The 2022 CGP requires a site map, description of grading timing, and
BMP maintenance schedule, but does not mandate a detailed list of all
subcontractors. Subcontractor information may be kept on-site but is
not a required SWPPP element. The other options are explicitly
required.
Page 3
, Question 4
A Walmart store's parking lot uses pervious concrete. After two years, the
infiltration rate has significantly decreased. Which maintenance practice is
most effective for restoring permeability?
A. Power washing the surface with high-pressure water.
B. Applying a sealant to prevent further clogging.
C. Vacuum sweeping with a regenerative air machine.
D. Overlaying with a thin layer of asphalt.
Correct Answer: C - Vacuum sweeping with a regenerative air
machine.
RATIONALE
Regenerative air vacuum sweeping removes fine sediments from pores
and is the recommended maintenance for pervious concrete. Power
washing can force particles deeper. Sealants clog pores. Asphalt
overlay defeats the purpose of pervious concrete.
Question 5
In a Walmart industrial facility, the SWPPP requires quarterly visual
monitoring of stormwater discharges. Which condition would exempt the
facility from sampling a particular outfall during a quarter?
A. The outfall is located in an arid region with no rainfall during the
quarter.
B. The outfall is equipped with an oil-water separator.
C. The facility has obtained a waiver from the state agency.
D. The outfall discharges only to a municipal separate storm sewer
system (MS4).
Correct Answer: A - The outfall is located in an arid region with
no rainfall during the quarter.
Page 4
A Walmart distribution center's industrial stormwater permit requires quarterly
sampling for total suspended solids (TSS) and zinc. The facility's SWPPP
specifies a benchmark of 100 mg/L for TSS. During a recent storm event, the
sample result was 150 mg/L. According to EPA's 2021 MSGP, what is the most
appropriate immediate action?
A. Report the exceedance to the state regulatory agency within 24 hours
and implement additional BMPs.
B. Conduct a follow-up sampling event within 30 days to confirm the
exceedance.
C. Document the exceedance in the SWPPP and review BMP
effectiveness during the next annual inspection.
D. Recalculate the benchmark using the facility's long-term average and
adjust the SWPPP accordingly.
Correct Answer: B - Conduct a follow-up sampling event within
30 days to confirm the exceedance.
RATIONALE
Under the 2021 MSGP, if a benchmark is exceeded, the facility must
conduct follow-up sampling within 30 days and review BMPs.
Immediate reporting is only required for exceedances of numeric
effluent limits, not benchmarks. Annual review is insufficient, and
recalculating benchmarks is not allowed.
Question 2
In designing a bioretention cell for a Walmart parking lot in a region with
clayey soils, which modification is most critical to ensure long-term infiltration
performance?
A. Increasing the depth of the ponding area to 12 inches.
B. Incorporating an underdrain system with a sand layer.
C. Planting only native grasses with deep taproots.
Page 2
, D. Adding a geotextile liner at the bottom.
Correct Answer: B - Incorporating an underdrain system with a
sand layer.
RATIONALE
Clayey soils have low infiltration rates; an underdrain with a sand
layer ensures proper drainage and prevents prolonged ponding.
Increasing ponding depth can lead to mosquito breeding and safety
issues. Deep-rooted plants help but cannot overcome low
permeability. A liner would prevent infiltration, defeating the purpose.
Question 3
A Walmart supercenter is undergoing a 5-acre expansion. The construction
stormwater permit requires a SWPPP. Which element is NOT required in the
SWPPP under the 2022 Construction General Permit (CGP)?
A. A site map showing drainage patterns and locations of BMPs.
B. A description of the timing of major grading activities.
C. A detailed list of all subcontractors and their contact information.
D. A maintenance schedule for all BMPs.
Correct Answer: C - A detailed list of all subcontractors and their
contact information.
RATIONALE
The 2022 CGP requires a site map, description of grading timing, and
BMP maintenance schedule, but does not mandate a detailed list of all
subcontractors. Subcontractor information may be kept on-site but is
not a required SWPPP element. The other options are explicitly
required.
Page 3
, Question 4
A Walmart store's parking lot uses pervious concrete. After two years, the
infiltration rate has significantly decreased. Which maintenance practice is
most effective for restoring permeability?
A. Power washing the surface with high-pressure water.
B. Applying a sealant to prevent further clogging.
C. Vacuum sweeping with a regenerative air machine.
D. Overlaying with a thin layer of asphalt.
Correct Answer: C - Vacuum sweeping with a regenerative air
machine.
RATIONALE
Regenerative air vacuum sweeping removes fine sediments from pores
and is the recommended maintenance for pervious concrete. Power
washing can force particles deeper. Sealants clog pores. Asphalt
overlay defeats the purpose of pervious concrete.
Question 5
In a Walmart industrial facility, the SWPPP requires quarterly visual
monitoring of stormwater discharges. Which condition would exempt the
facility from sampling a particular outfall during a quarter?
A. The outfall is located in an arid region with no rainfall during the
quarter.
B. The outfall is equipped with an oil-water separator.
C. The facility has obtained a waiver from the state agency.
D. The outfall discharges only to a municipal separate storm sewer
system (MS4).
Correct Answer: A - The outfall is located in an arid region with
no rainfall during the quarter.
Page 4
