HomeMy WebLinkAboutVAR_Option_1_FINAL_05_19_2022VAR Option:1 Page 1
Rev 05/19/2022
NC DEQ/DWR WASTEWATER/GROUNDWATER LABORATORY CERTIFICATION BRANCH
LABORATORY NAME: CERT #:
PRIMARY ANALYST: DATE:
NAME OF PERSON COMPLETING CHECKLIST (PRINT):
SIGNATURE OF PERSON COMPLETING CHECKLIST:
Parameter: Vector Attraction Reduction
Method: Option 1: Reduction in Volatile Solids Content [40 CFR 503.33(b)(1)]
Control of Pathogens and Vector Attraction in Sewage Sludge, EPA/625/R-92/013
Equipment:
Muffle furnace for operation at 550°C Mixing Paddle
Desiccator, provided with a desiccant
containing a color indicator of moisture
concentration or an instrumental
indicator
Drying oven, for operation at 103 to
105°C Evaporating dishes of 100-mL
capacity Analytical balance, capable of
weighing to 10 mg
PLEASE COMPLETE CHECKLIST IN INDELIBLE INK
Please mark Y, N or NA in the column labeled LAB to indicate the common lab practice
and in the column labeled SOP to indicate whether it is addressed in the SOP.
GENERAL
L
A
B
S
O
P
EXPLANATION
1
Is the SOP reviewed at least every 2 years? What is the
most recent review/revision date of the SOP? [15A NCAC
2H .0805 (a) (7)]
Date:
Quality assurance, quality control, and Standard
Operating Procedure documentation shall indicate the
effective date of the document and be reviewed every two
years and updated if changes in procedures are made.
Verify proper method reference. During review notate
deviations from the approved method and SOP.
2 Are all review/revision dates and procedural edits tracked
and documented? [15A NCAC 2H .0805 (a) (7)]
Each laboratory shall have a formal process to track and
document review dates and any revisions made in all
quality assurance, quality control and SOP documents.
3
Has the laboratory developed and implemented a
documented training program? [15A NCAC 2H .0805 (a) (7)
(P)]
Each laboratory shall develop and implement a
documented training program that includes documentation
that: (i) that staff have the education, training, experience,
or demonstrated skills needed to generate quality control
results within method-specified limits and that meet the
requirements of these Rules; (ii) that staff have read the
laboratory quality assurance manual or applicable Standard
Operating Procedures; (iii) that staff have obtained
acceptable results on Proficiency Testing samples pursuant
to Rule .0803(1) of this Section or other demonstrations of
proficiency (e.g., side-by-side comparison with a trained
analyst, acceptable results on a single-blind performance
evaluation sample, an initial demonstration of capability
study prescribed by the reference method).
4 Is there North Carolina data available for review?
PROCEDURE – Sample Preparation
L
A
B
S
O
P
EXPLANATION
5 Are clean evaporating dishes ignited at 550°C ±50°C for
≥15 min in a muffle furnace? [SM 2540 G-2015 (3) (a) (1)]
6 Are ignited dishes then cooled in a desiccator to ambient
temperature and weighed? [SM 2540 G-2015 (3) (a) (1)]
7 Are evaporating dishes stored in a desiccator or 103-
105°C oven until needed? [SM 2540 G-2015 (3) (a) (1)]
8
Do samples qualify to be analyzed according to Option 1?
[Control of Pathogens and Vector Attraction in Sewage
Sludge, EPA/625/R-92/013, (July 2003) (8.2)]
This option is intended for use with biological treatment
systems only. Under Option 1, reduction of vector
attraction is achieved if the mass of volatile solids in the
sewage sludge is reduced by at least 38%. This is the
percentage of volatile solids reduction that can generally
be attained by the “good practice” recommended
conditions for anaerobic digestion of 15 days residence
VAR Option:1 Page 2
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time at 35°C [95°F] in a completely mixed high-rate
digester. The percent volatile solids reduction can include
any additional volatile solids reduction that occurs before
the biosolids leave the treatment works, such as might
occur when the sewage sludge is processed on drying
beds or in lagoons.
9
What is the starting point where the samples are
collected? [Control of Pathogens and Vector Attraction in
Sewage Sludge, EPA/625/R-92/013, (July 2003) (8.2)]
[Control of Pathogens and Vector Attraction in Sewage
Sludge, EPA/625/R-92/013, (July 2003) Appendix C]
Answer:
The starting point for measuring volatile solids in
sewage sludge is at the point at which sewage sludge
enters a sewage sludge treatment process. This can
be problematic for facilities in which wastewater is
treated in systems like oxidation ditches or by
extended aeration. Sewage sludges generated in these
processes are already substantially reduced in volatile
solids content by their long exposure to oxidizing
conditions in the process. If sewage sludge removed
from these processes is further treated by anaerobic
or aerobic digestion to meet VAR requirements, it is
unlikely that the 38% reduction required to meet
Option 1 can be met. In these cases, use of Options 2,
3, or 4 is more appropriate.
For most processing sequences, the processing steps
downstream from the digester, such as short-term storage
or dewatering, have no influence on volatile solids
content. Consequently, the appropriate comparison is
between the sewage sludge entering the digester and the
sewage sludge leaving the digester.
10
What is the end point where the samples are collected?
[Control of Pathogens and Vector Attraction in Sewage
Sludge, EPA/625/R-92/013, (July 2003) (8.2)] [Control of
Pathogens and Vector Attraction in Sewage Sludge,
EPA/625/R-92/013, (July 2003) Appendix C]
Answer:
The end point where volatile solids are measured to
calculate volatile solids losses can be at any point in the
process. Because volatile solids continue to degrade
throughout sewage sludge treatment, it is recommended
that samples be taken at the end point of treatment.
For most processing sequences, the processing steps
downstream from the digester, such as short-term storage
or dewatering, have no influence on volatile solids
content. Consequently, the appropriate comparison is
between the sewage sludge entering the digester and the
sewage sludge leaving the digester.
The sampling point for the “after treatment” measurement
can be immediately leaving the processing unit or at the
point of use or disposal, provided there has been no
significant dilution downstream with inert solids.
PROCEDURE – Sample Analysis
L
A
B
S
O
P
EXPLANATION
11
What amount of biosolids were used or disposed in the
previous year? [Control of Pathogens and Vector
Attraction in Sewage Sludge, EPA/625/R-92/013, (July
2003) (9.5)]
Answer:
12
What is the lab’s sampling frequency? [15A NCAC
02T .1111 (c) and Control of Pathogens and Vector
Attraction in Sewage Sludge, EPA/625/R-92/013, (July
2003) (9.5)]
Answer:
It is obviously not feasible to sample and analyze every
load of biosolids leaving a facility, nor is it necessary.
However, a sampling plan does need to adequately
account for the variability of the biosolids. This entails
collecting samples at an adequate frequency and
analyzing a sufficient number of samples. The minimum
sampling frequency and number of samples to be
analyzed are shown in 40 CFR Part 503. As shown in
Table 3-4, the sample collection frequency is determined
by the amount of biosolids used or disposed.
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13
How are samples collected? [Control of Pathogens and
Vector Attraction in Sewage Sludge, EPA/625/R-92/013,
(July 2003) Appendix C]
Answer:
The principal cause of error is poor sampling. Samples
should be representative, covering the entire charging
and withdrawal periods. Averages should cover extended
periods of time during which changes in process
conditions are minimal.
14
How is the sample homogenized? [SM 2540 G-2015 (3)
(a) (2) (a) and (b)]
Answer:
Fluid samples: If sample contains enough moisture to
flow readily, then stir or shake to homogenize
Solid samples: If sample consists of discrete pieces of
solid material (e.g., dewatered sludge) then take care to
obtain a representative sample whose particle size will
not impede drying…
Manually process samples as quickly as possible to
prevent moisture loss. Processing via mechanical
grinding is not recommended because moisture levels
could drop during processing.
15
Is 25 to 50 grams of homogenized sample placed in a
prepared evaporating dish and weighed? [SM 2540 G-
2015 (3) (a) (2) (a) and (b)]
16
Are fluid samples evaporated to dryness and then dried in
an oven at 103 to 105°C for ≥ 1 hour? [SM 2540 G-2015
(3) (a) (2) (a)]
Evaporate to dryness on a water bath, on a hot plate or
block, or in a drying oven, then dry the evaporated
sample at 103 -105°C for ≥ 1 h.
17 Are solid samples placed in a 103 to 105°C oven for ≥ 1
hour? [SM 2540 G-2015 (3) (a) (2) (b)]
18
Are samples cooled to ambient temperature in a
desiccator, and weighed? [SM 2540 G-2015 (3) (a) (2) (a)
and (b)]
cool to ambient temperature in a desiccator, and weigh.
19
Is the heating, cooling, desiccating, and weighing
procedure repeated until the weight change is <50 mg?
[SM 2540 G-2015 (3) (a) (2) (a) and (b)]
Repeat cycle (drying, cooling, desiccating, and weighing)
until the weight change is <50 mg.
20
Is the dried residue transferred to a cool muffle furnace,
and then ignited at 550°C ±50°C for ≥ 1 hour? [SM 2540
G-2015 (3) (b)]
Fixed and volatile solids: Transfer the dried residue to a
cool muffle furnace, heat furnace to 550°C ±50°C, and
the allow ignition to occur for ≥ 1 h.
21 Are samples cooled to ambient temperature in a
desiccator, and weighed? [SM 2540 G-2015 (3) (b)] Cool in desiccator to ambient temperature and weigh.
22
Are the igniting, cooling, desiccating and weighing steps
repeated until the weight change is <50 mg? [SM 2540 G-
2015 (3) (b)]
Repeat cycle (igniting, cooling, desiccating, and weighing)
until the weight change is <50 mg.
23
How are percent volatile solids calculated? [SM 2540 G-
2015 (4)]
Answer:
This equation is simpilified from SM to determine percent
volatile solids in the decimal form.
Percent volatile solids (in decimal form) =
24 How is the fractional volatile solids reduction calculated?
VAR Option:1 Page 4
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[Control of Pathogens and Vector Attraction in Sewage
Sludge, EPA/625/R-92/013, (July 2003) Appendix C]
Answer:
The following equation appears on the NC Operator’s
Exam formulas page as a version of the Van Kleek
formula.
% Volatile Solids Destroyed in a digester:
25 Is the calculated fractional volatile solids reduction result
at least 38%? [15A NCAC 02T .1107 (a) (1)]
The mass of the volatile solids in the biological residuals
shall be reduced by a minimum of 38 percent between the
time that the biological residuals enter the digestion
process and the time it is land applied.
QUALITY ASSURANCE
L
A
B
S
O
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EXPLANATION
26
Are duplicates analyzed at a frequency of ≥5% of a batch
of ≤20 samples each day? [SM 2540 A-2015 (5)]
Analyze ≥5% of all samples in duplicate or at least one
duplicate sample with each batch of ≤20 samples.
27
What is the acceptance criterion for duplicates? [15A
NCAC 2H .0805 (a) (7) (A)]
Answer:
SM 2540 A-2015 (5) states: Typically, the relative percent
difference (RPD) of duplicates should not exceed 10%,
but RPDs may vary considerably due to sample matrix
and concentration.
This is not required, and the acceptance criterion is to be
set by the laboratory.
28
What corrective action does the laboratory take if the
duplicate samples results are outside of established control
limits? [15A NCAC 2H .0805 (a) (7) (B)]
Answer:
If quality control results fall outside established limits or
show an analytical problem, the laboratory shall identify
the Root Cause of the failure. The problem shall be
resolved through corrective action, the corrective action
process documented, and any samples involved shall be
reanalyzed, if possible.
29
Is the analytical balance being serviced every 12 months by
a qualified vendor/technician? [15A NCAC 2H .0805 (a) (7)
(J)]
Laboratory analytical balances shall be serviced by a
metrology vendor or technician every 12 months to verify
that the balance is functioning within manufacturer's
specifications.
30
Does the laboratory have documentation to verify that the
balance has been serviced? [15A NCAC 2H .0805 (a) (7)
and (a) (7) (E)]
Supporting Records shall be maintained as evidence that
these practices are implemented.
All analytical data and records pertinent to each certified
analysis shall be available for inspection upon request.
31 Is the laboratory using ASTM Type 1, Class 1 or 2, or
equivalent weights? [15A NCAC 2H .0805 (a) (7) (J)]
The analytical balance shall be checked with one ASTM
Type 1, Class 1 or 2, or equivalent standard weight each
day used.
32
Are the weights being verified every 5 years? [15A NCAC
2H .0805 (a) (7) (J)] [NC WW/GW LCB Policy]
These weights shall be verified every five years.
Verification may be accomplished by:
1. Sending laboratory weights back to the manufacturer
for recertification - reference weights shall be calibrated
by a body that can provide traceability to ASTM
specifications, or
2. Checking laboratory weights against certified reference
weights (i.e., weights that have been recertified as
above) and found to be within ASTM Type I tolerances
(see Weight Verification policy) - often the balance
service technician may provide this service.
33
Does the laboratory have documentation indicating that the
weights were verified? [15A NCAC 2H .0805 (a) (7)]
Supporting Records shall be maintained as evidence that
these practices are implemented.
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Date Verified:
Documentation of weight verifications or recertification must
be maintained for 5 years. If the condition of a weight(s) is in
question at any time due to damage (e.g., corrosion, nicks,
scratching, etc.), the laboratory must have that weight(s) re-
verified as described above.
34
Is the balance checked with a weight each day of use?
[15A NCAC 2H .0805 (a) (7) (J)]
List weight:
The analytical balance shall be checked with one ASTM
Type 1, Class 1 or 2, or equivalent standard weight each
day used.
35 Is this documented? [15A NCAC 2H .0805 (a) (7) (J)] The values obtained shall be recorded, dated, and initialed.
36
Is the balance checked with at least three weights monthly?
[15A NCAC 2H .0805 (a) (7) (J)]
List weights:
The analytical balance shall be verified monthly with three
ASTM Type 1, Class 1 or 2, or equivalent standard weights
across the range of use.
37 Is this documented? [15A NCAC 2H .0805 (a) (7) (J)] The values obtained shall be recorded, dated, and initialed.
38
Is the data qualified on the EPA Biosolids Annual Report
(NPDES Form 6100-035) or client report if Quality Control
(QC) requirements are not met? [15A NCAC 2H .0805 (a)
(7) (B)]
If quality control results fall outside established limits or
show an analytical problem, the laboratory shall identify
the Root Cause of the failure. The problem shall be
resolved through corrective action, the corrective action
process documented, and any samples involved shall be
reanalyzed, if possible. If the sample cannot be
reanalyzed, or if the quality control results continue to fall
outside established limits or show an analytical problem,
the results shall be qualified as such.
Additional Comments:
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Inspector: ______________________________________________________Date:_________________________________________