RADON REVIEW QUIZ 6 (MITIGATION)
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS
A measurement of the differential pressure across a slab is carried out by a mitigator
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on a day characterized by gusts of wind. In comparison to measurements made on a
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calm day, the windy day pressure differential readings across the slab will:
fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. Remain constant
fx fx
b. Increase
fx
c. Fluctuate
fx
d. Decrease - ANSWERS-c. Fluctuate
fx fx fx fx
A mitigator is called to a house with a basement that has a radon reading of 20 pCi/
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L. Half of the basement is finished, and it has parquet flooring. Since all diagnostic te
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sting is to be performed, which of the following would be the most logical test to perfor
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m FIRST? fx
Select one: fx
a. Suction-
fx
field extension testing in the unfinished portion of the basement, with one or two vacu
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
um-cleaner suction holes, and with pressure- fx fx fx fx fx
test holes at distances of 1, 5, 10, and 15 feet in at least two directions away from eac
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
h test hole.
fx fx
b. Suction-field extension testing, with one vacuum-
fx fx fx fx fx fx
cleaner suction hole each in the finished and unfinished portions of the basement, an
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d four pressure-test holes (one in each corner) in each portion.
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c. Sub-
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slab radon concentration measurements, through three or four sample holes each in t
fx fx fx fx fx fx fx fx fx fx fx fx
he finished and unfinished portions of the basement.
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d. Suction-field extension testing in the unfinished port - ANSWERS-d. Suction-
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field extension testing in the unfinished portion of the basement, with one vacuum-
fx fx fx fx fx fx fx fx fx fx fx fx
cleaner suction hole, and one to four pressure-
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test holes at remote corners of the unfinished portion.
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A Pressure Field Extension (PFE) diagnostic test has been conducted with a vacuum
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xcleaner attached at preferred sub-slab suction point via a 2-foot length of 3-
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inch pipe. Three pitot tube measurements to determine air volume were made with re
fx fx fx fx fx fx fx fx fx fx fx fx fx
sults of 0.045, 0.036 and 0.058 inches of water column. How much air is being extrac
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
ted by your shop vacuum (assuming an air temperature of 70 degrees F)?
fx fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. 41 CFMfx fx
b. 5,828 CFM
fx fx
c. 72 CFM
fx fx
d. 88 CFM - ANSWERS-a. 41 CFM
fx fx fx fx fx fx
, Assuming a pipe diameter of 3 inches since that is what you made the pitot tube mea
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surements inside, one multiplies the velocity obtained by the cross-
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sectional area of the pipe. fx fx fx fx
Cross sectional Area = п r2 fx fx fx fx fx
Cross sectional area of 3 inch pipe = 3.14 x 1.52 = 3.14 x 2.25 = 7.065 sq inches.
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Cross Sectional Area =7.065 sq in / 144 = 0.049 sq ft
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825 Feet per minute x 0.049 Sq feet = 40.5 CFM Cubic Feet per Minute (round up to
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
41 CFM) fx
A radon mitigation worker spends a day and a half working in a house that had been
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
previously tested at 12 pCi/L with a follow-up test of 8 pCi/
fx fx fx fx fx fx fx fx fx fx fx
L. What exposure has the worker received that would be recorded in their file, assumi
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
ng after completing the job he/she went fishing rather than start another radon job?
fx fx fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. 0.080 WLM
fx fx
b. 0.0085 WLM
fx fx
c. 0.0094 WLM
fx fx
d. 0.0042 WLM - ANSWERS-b. 0.0085 WLM
fx fx fx fx fx fx
Calculate radon decay products in units of WL assuming a 100% Equilibrium Factor
fx fx fx fx fx fx fx fx fx fx fx fx
WL = 12 * 1.0/100 = 0.12 WL
fx fx fx fx fx fx fx
WLM = WL x hours/170 hours fx fx fx fx fx
A single point sub-
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slab suction system was installed in a basement house, with a 200-
fx fx fx fx fx fx fx fx fx fx fx
cfm fan capable of drawing 1.5 inches of water (WC) suction. Radon levels, however,
fx fx fx fx fx fx fx fx fx fx fx fx fx f
xare still somewhat elevated. During cold weather, suctions are measured under the s
fx fx fx fx fx fx fx fx fx fx fx fx
lab in four test holes, each 15 feet away from the suction pipe in a different direction.
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
The pressure differentials across the slab at the four holes are: Hole A: -
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0.015 inch of water (WC); Hole B: -0.02 inch of water (WC); Hole C: -
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
0.002 inch of water (WC); Hole D: +0.002 inch of water (WC). Measurements in the s
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
uction pipe indicate flows of 150 cfm and suction of 0.1 inch of water (WC). From the
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
available information, which of the following would be the most reasonable next respo
fx fx fx fx fx fx fx fx fx fx fx fx
nse?
Select one: fx
a. Immediately install two additional suction pipes in the vicinity of holes C and D.
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b. Remove the pipe and excavate a hole of at least 2 cubic feet underneath the slab a
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t - ANSWERS-
fx fx
c. Inspect the system piping and the slab for sites where basement air could be leakin
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g into the system; close any leaks discovered.
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A sole proprietor is required to develop a Mitigation Installer Protection Plan.
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QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS
A measurement of the differential pressure across a slab is carried out by a mitigator
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
on a day characterized by gusts of wind. In comparison to measurements made on a
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
calm day, the windy day pressure differential readings across the slab will:
fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. Remain constant
fx fx
b. Increase
fx
c. Fluctuate
fx
d. Decrease - ANSWERS-c. Fluctuate
fx fx fx fx
A mitigator is called to a house with a basement that has a radon reading of 20 pCi/
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
L. Half of the basement is finished, and it has parquet flooring. Since all diagnostic te
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
sting is to be performed, which of the following would be the most logical test to perfor
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
m FIRST? fx
Select one: fx
a. Suction-
fx
field extension testing in the unfinished portion of the basement, with one or two vacu
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
um-cleaner suction holes, and with pressure- fx fx fx fx fx
test holes at distances of 1, 5, 10, and 15 feet in at least two directions away from eac
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
h test hole.
fx fx
b. Suction-field extension testing, with one vacuum-
fx fx fx fx fx fx
cleaner suction hole each in the finished and unfinished portions of the basement, an
fx fx fx fx fx fx fx fx fx fx fx fx fx
d four pressure-test holes (one in each corner) in each portion.
fx fx fx fx fx fx fx fx fx fx
c. Sub-
fx
slab radon concentration measurements, through three or four sample holes each in t
fx fx fx fx fx fx fx fx fx fx fx fx
he finished and unfinished portions of the basement.
fx fx fx fx fx fx fx
d. Suction-field extension testing in the unfinished port - ANSWERS-d. Suction-
fx fx fx fx fx fx fx fx fx fx
field extension testing in the unfinished portion of the basement, with one vacuum-
fx fx fx fx fx fx fx fx fx fx fx fx
cleaner suction hole, and one to four pressure-
fx fx fx fx fx fx fx
test holes at remote corners of the unfinished portion.
fx fx fx fx fx fx fx fx
A Pressure Field Extension (PFE) diagnostic test has been conducted with a vacuum
fx fx fx fx fx fx fx fx fx fx fx fx f
xcleaner attached at preferred sub-slab suction point via a 2-foot length of 3-
fx fx fx fx fx fx fx fx fx fx fx fx
inch pipe. Three pitot tube measurements to determine air volume were made with re
fx fx fx fx fx fx fx fx fx fx fx fx fx
sults of 0.045, 0.036 and 0.058 inches of water column. How much air is being extrac
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
ted by your shop vacuum (assuming an air temperature of 70 degrees F)?
fx fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. 41 CFMfx fx
b. 5,828 CFM
fx fx
c. 72 CFM
fx fx
d. 88 CFM - ANSWERS-a. 41 CFM
fx fx fx fx fx fx
, Assuming a pipe diameter of 3 inches since that is what you made the pitot tube mea
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
surements inside, one multiplies the velocity obtained by the cross-
fx fx fx fx fx fx fx fx fx
sectional area of the pipe. fx fx fx fx
Cross sectional Area = п r2 fx fx fx fx fx
Cross sectional area of 3 inch pipe = 3.14 x 1.52 = 3.14 x 2.25 = 7.065 sq inches.
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
Cross Sectional Area =7.065 sq in / 144 = 0.049 sq ft
fx fx fx fx fx fx fx fx fx fx fx
825 Feet per minute x 0.049 Sq feet = 40.5 CFM Cubic Feet per Minute (round up to
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
41 CFM) fx
A radon mitigation worker spends a day and a half working in a house that had been
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
previously tested at 12 pCi/L with a follow-up test of 8 pCi/
fx fx fx fx fx fx fx fx fx fx fx
L. What exposure has the worker received that would be recorded in their file, assumi
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
ng after completing the job he/she went fishing rather than start another radon job?
fx fx fx fx fx fx fx fx fx fx fx fx fx
Select one: fx
a. 0.080 WLM
fx fx
b. 0.0085 WLM
fx fx
c. 0.0094 WLM
fx fx
d. 0.0042 WLM - ANSWERS-b. 0.0085 WLM
fx fx fx fx fx fx
Calculate radon decay products in units of WL assuming a 100% Equilibrium Factor
fx fx fx fx fx fx fx fx fx fx fx fx
WL = 12 * 1.0/100 = 0.12 WL
fx fx fx fx fx fx fx
WLM = WL x hours/170 hours fx fx fx fx fx
A single point sub-
fx fx fx
slab suction system was installed in a basement house, with a 200-
fx fx fx fx fx fx fx fx fx fx fx
cfm fan capable of drawing 1.5 inches of water (WC) suction. Radon levels, however,
fx fx fx fx fx fx fx fx fx fx fx fx fx f
xare still somewhat elevated. During cold weather, suctions are measured under the s
fx fx fx fx fx fx fx fx fx fx fx fx
lab in four test holes, each 15 feet away from the suction pipe in a different direction.
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
The pressure differentials across the slab at the four holes are: Hole A: -
fx fx fx fx fx fx fx fx fx fx fx fx fx
0.015 inch of water (WC); Hole B: -0.02 inch of water (WC); Hole C: -
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
0.002 inch of water (WC); Hole D: +0.002 inch of water (WC). Measurements in the s
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
uction pipe indicate flows of 150 cfm and suction of 0.1 inch of water (WC). From the
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
available information, which of the following would be the most reasonable next respo
fx fx fx fx fx fx fx fx fx fx fx fx
nse?
Select one: fx
a. Immediately install two additional suction pipes in the vicinity of holes C and D.
fx fx fx fx fx fx fx fx fx fx fx fx fx fx
b. Remove the pipe and excavate a hole of at least 2 cubic feet underneath the slab a
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
t - ANSWERS-
fx fx
c. Inspect the system piping and the slab for sites where basement air could be leakin
fx fx fx fx fx fx fx fx fx fx fx fx fx fx fx
g into the system; close any leaks discovered.
fx fx fx fx fx fx fx
A sole proprietor is required to develop a Mitigation Installer Protection Plan.
fx fx fx fx fx fx fx fx fx fx fx
