US Environmental Protection Agency
Office of Pesticide Programs

Office of Pesticide Programs

Microbiology Laboratory

Environmental Science Center, Ft. Meade, MD

Standard Operating Procedure for
Quality Assurance of Purified Water

SOP Number: QC-01-05

Date Revised: 10-25-11


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SOP No. QC-01-05
Date Revised 10-25-11
Page 1 of 18

EPA/OPP MICROBIOLOGY LABORATORY
ESC, Ft. Meade, MD

Standard Operating Procedure
for

Quality Assurance of Purified Water

SOP Number: QC-01-05

Date Revised: 10-25-11

Initiated By:		Date: / /

Print Name:	

Technical Review:	Date: / /

Print Name:

Technical Staff

QA Review:		Date: / /

Print Name:	

QA Officer

Approved By:		Date: / /

Print Name:	

Branch Chief

Effective Date: 	/	/	

Controlled Copy No.:	

Withdrawn By:

Date: / /


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SOP No. QC-01-05
Date Revised 10-25-11
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TABLE OF CONTENTS

Contents	Page Number

1.0	SCOPE AM) APPLICATION	3

2.0	DEFINITIONS	3

3.0	HEALTH AND SAFETY	3

4.0	CAUTIONS	3

5.0	INTERFERENCES	3

6.0	PERSONNEL QUALIFICATIONS	4

7.0	SPECIAL APPARATUS AND MATERIALS	4

8.0	INSTRUMENT OR METHOD CALIBRATION	5

9.0	SAMPLE HANDLING AND STORAGE	5

10.0	PROCEDURE AM) ANALYSIS	5

11.0	DATA ANALYSIS/CALCULATIONS	10

12.0	DATA MANAGEMENT/RECORDS MANAGEMENT	11

13.0	QUALITY CONTROL	11

14.0	NONCONFORMANCE AND CORRECTIVE ACTION	11

15.0	REFERENCES	12

16.0	FORMS AM) DATA SHEETS	 13


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1.0 SCOPE AND APPLICATION:

1.1 This protocol outlines the procedures for monitoring the quality of the deionized
water used in the laboratory to make media, reagents and disinfectants.

2.0 DEFINITIONS: None.

3.0 HEALTH AND SAFETY:

3.1 Several of the tests to be performed on the purified water require that the sample
water be preserved with sulfuric or nitric acid. To protect against possible
chemical burns, the laboratory worker must wear a lab coat, gloves, and
protective eyewear (e.g., glasses or goggles) while filling water sample bottles
containing sulfuric or nitric acid.

4.0 CAUTIONS:

4.1	Let the water run for approximately 30 seconds prior to filling sample collection
bottles.

4.2	The water collected for the heterotrophic plate counts must be analyzed by QC
Laboratories within 30 hours of collection and must be kept cold during transit by
packing the container with ice packs. The samples should be collected on the
same day, and as close to the FedEx pickup time as practicable.

4.3	To maintain evidence of chain of custody and to ensure that the testing laboratory
performs the analyses requested by the ESC/OPP Microbiology Laboratory, the
vendor chain of custody forms and the sample identification labels must be
legibly completed.

4.4	Ship water samples to vendors on Mondays, Tuesdays, and Wednesdays only to
ensure that the samples arrive prior to a weekend.

5.0 INTERFERENCES:

5.1 Each new lot of the DPD Powder Pillows reagent (i.e., DPD [salt of N,N-Di ethyl-
p-Phenylenediamine Potassium Iodide Sodium Phosphate, Dibasic] Total
Chlorine Reagent Powder Pillows) should be checked for reagent accuracy. If the
DPD Powder Pillows do not demonstrate reagent accuracy, the total chlorine
residual test may be jeopardized. See section 10.13 for a description of the
method to check reagent accuracy.

5.2 Discard expired DPD Total Chlorine Reagent Powder Pillows.


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5.3	All test parameters will be conducted at the monitoring frequency indicated in
Table 1. Monitoring Frequency and Acceptable Limits for Water Quality
Parameters (section 10.2).

5.4	Individual test parameters will be tested more frequently than described in Table
1. Monitoring Frequency and Acceptable Limits for Water Quality Parameters
(section 10.2) if a problem with water quality is identified (see 11.0 and 14.0).
The laboratory may opt to test the water whenever the source of the water is
changed, there is an upgrade, or there is a known failure of the building's
deionized water system.

6.0 PERSONNEL QUALIFICATIONS:

6.1 Personnel are required to be knowledgeable of the procedures in this SOP.

Documentation of training and familiarization with this SOP can be found in the
training file for each employee.

7.0 SPECIAL APPARATUS AND MATERIALS:

7.1	The deionized water port on the north wall of room B206 is outfitted with a
Barnstead B-pure Pressure Cartridge System. The Barnstead B-pure Pressure
Cartridge System contains cartridges which raise the quality of the deionized
water. Refer to the Barnstead B-pure Pressure Cartridge System Operation
Manual and Parts List, Series 583 for operation and maintenance of the equipment
and instructions on changing filters (see ref. 15.1).

7.2	Vendor-supplied test request/chain of custody forms and water collection bottles.
Contact vendor to obtain additional forms and bottles.

7.3	Styrofoam shipping container

7.4	Refrigerant packs

7.5	Hach Total Chlorine Test Kit, 0-3.5 mg/L (Hach catalog number 2231-03)

7.6	Isopropyl alcohol

7.7	Soft cloth (e.g., Texwipe TX409 absorbent wipers)

7.8	Chlorine Standard Solution, 50-75 mg/L, 2-mL PourRite ampule (Hach catalog
number 14268-20)


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7.9 Nalgene 16 oz. leak-proof environmental sampling bottles (Nalgene part number
332189-0016).

8.0 INSTRUMENT OR METHOD CALIBRATION: Not applicable

9.0 SAMPLE HANDLING AND STORAGE:

9.1 Refer to section 4.0 for sample handling and storage conditions.

10.0 PROCEDURE AND ANALYSIS:

10.1	The water used in the laboratory to make media and reagents and to dilute
disinfectants during efficacy testing is taken from the Barnstead B-pure Pressure
Cartridge System filtration unit on the north wall of room B206. Consequently,
this is the source of the water collected for quality assurance testing (see 4.1).

10.2	The water is checked for specific heavy metals (cadmium [Cd], lead [Pb], nickel
[Ni], zinc [Zn], copper [Cu], and chromium [Cr]), total heavy metals (cumulative
value of the six specific heavy metals), total organic carbon, conductivity, total
chlorine residual, heterotrophic plate counts, and water quality/suitability. The
frequency of testing and accepted limits of water quality as specified in "Standard
Methods", Table 9020: II (see ref. 15.2) are presented in Table 1 below:

Table 1. Monitoring frequency and acceptable limits for water quality parameters.

Test

Monitoring Frequency

Accepted Limits

Heavy Metals, Total

Annually

<0.10 mg/L*

Heavy Metals, Single
(Cd, Cr, Cu, Ni, Pb, and
Zn)

Annually

< 0.05 mg/L

Water Quality (or Water Suitability)
Test

Annually

0.8 to 3.0 ratio

Total Organic Carbon

Monthly

<1.0 mg/L

Conductivity

Monthly

< 2 umhos/cm at 25EC

Total Chlorine Residual

Monthly

<0.1 mg/L**

Heterotrophic Plate Counts

Monthly

< 500 Colony Forming
Units/mL (CFU/mL)

*The accepted limit for total heavy metals is determined by finding the cumulative value of the six
specific heavy metals. If the testing result for the specific heavy metals are "not detected",
determine the cumulative value of the reportable limits (RL). This value must be below 0.10 mg/L.
**As detected by Hach Total Chlorine Test Kit (0.0-3.5 mg/L)


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10.2.1	The Barnstead B-pure Pressure Cartridge System filtration unit in room
B206 has an in-line resistivity meter which continuously reads and
displays the resistivity of the water (in megohms resistance, inverse of
umhos/cm). When using water for any purpose, the lab staff must monitor
the resistivity meter, while the water is flowing, to ensure that the water
demonstrates > 0.5 megohms resistance (same as < 2 umhos/cm). The
resistance reading must be recorded once for every day of use in the
Purified Water Resistivity Record (see 16.4). If the resistivity falls below
0.5 megohms, see 14.0 for suggested corrective actions or inform the
analyst currently responsible for verifying the quality of the deionized
water.

10.2.2	The Use test specified in Table 9020:11 (see reference 15.2 page 9-7) is
performed only when a new source of reagent grade water is used (i.e.,
new source or lot of bottled water). This test is not applicable to the
laboratory.

10.3	Monitoring of total heavy metals, specific heavy metals, total organic carbon,
conductivity, heterotrophic plate counts, and water suitability is performed by a
competent vendor.

10.4	When sampling each month, legibly, in ink, complete the vendors test
request/chain of custody form.

10.5	Collect the water for analysis from the Barnstead B-Pure filtration unit on the
north wall of room B206 by filling the appropriate sample collection bottle as
indicated in Table 2 below:

Table 2. Collection specifications for water quality parameters.

Test

Type of Collection Bottle/
Preservative

Heavy Metals, Single
(Cd, Cr, Cu, Ni, Pb, and Zn)

One Pint/Nitric Acid

Total Organic Carbon

One Pint/Sulfuric Acid*

Conductivity

One Pint/No Preservative

Heterotrophic Plate Counts

Sterile Bottle/No
Preservative

Water Quality (or Water
Suitability Test)

Square, Glass Bottle/No
Preservative

*Note: Collect the water for analysis by filling one Nalgene 16 oz. leak-proof environmental
sampling bottle. Close the sample bottle and transport it to the fume hood in B203. Remove the
cap from the sample bottle. While wearing nitrile gloves, use a glass Pasteur pipet to add 4-6


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drops of sulfuric acid to the water sample. Remove the bulb and place the Pasteur pipet, tip down,
in a sterile beaker. Put the cap back on the sample bottle and invert the sample bottle several
times. Turn on the tap water. Pour out the excess sulfuric acid from the beaker into the sink and
rinse out the beaker with water. Set it aside to be washed. Place the Pasteur pipets under gently-
running water and rinse out the excess acid. Dispose of the pipets in a broken glass box.

10.6	As each individual sample collection bottle is filled, legibly write the collection
time (in military time) on the appropriate vendor sample identification label and
on the test request/chain of custody form.

10.6.1	After filling the heterotrophic plate count sample collection bottle,

place the bottle in the refrigerator until all other bottles have been
filled, labeled, and placed in the shipping container.

10.7	Water Suitability Test: Collect deionized water in the bottle supplied by the
vendor. Place the glass bottle (loosely capped) on a hotplate and bring the water
slowly to a boil over medium-high heat. Do not turn the hotplate dial to "high" as
the rapid heating process may cause the glass bottle to break. After the water has
boiled for 2 minutes, remove the bottle from the hotplate and let cool on the bench
top. Once cool, tighten the cap and package the bottle for shipment.

10.8	Once all sample collection bottles have been filled and the collection time
recorded on the vendor sample identification labels and the test request/chain of
custody form, place the bottles in a styrofoam shipping container. Remove the
heterotrophic plate count sample collection bottle from the refrigerator, place it in
a plastic bag with one to two ice packs, and tape or tie the bag closed. Place the
bag in the shipping container.

10.9	Add packing material to the sample collection bottles to prevent the bottles from
moving during shipment.

10.10	Complete the vendor chain of custody form and prepare for shipment.

10.10.1	Place the vendor test request/chain of custody form in a plastic bag

and tape or tie it closed. Place the bag in the shipping container
and tape the container closed.

10.11	Ship the package by priority overnight shipping.

10.12	Chlorine Residual Test: Monitor the total chlorine residual of the water each
month using the Hach Total Chlorine Test Kit, 0-3.5 mg/L (Hach catalog number
2231-03).

10.12.1

Clean a beaker and the kit's plastic viewing tubes and caps with


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SOP No. QC-01-05
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isopropyl alcohol or a non-abrasive detergent prior to commencing
the test. Rinse several times with the sample deionized water
(from the Barnstead B-Pure filtration unit on the north wall of
room B206). Use a soft cloth for wiping or drying the plastic
viewing tubes. Do not use paper towels or tissue as this may
scratch the plastic.

10.12.2	Collect sample water from the Barnstead B-Pure filtration unit on
the north wall of room B206 in the beaker. Pour water from the
beaker into one plastic viewing tube until the water level reaches
the first line (bottom edge of the frosted area-equals 5 mL). This is
the blank.

10.12.3	Place the blank in the top left opening of the color comparator.

10.12.4	Fill the second plastic viewing tube to the first line (bottom edge of
the frosted area) with sample water from the beaker.

10.12.5	Add the contents of one DPD (salt of N,N-Diethyl-p-
Phenylenediamine Potassium Iodide Sodium Phosphate, Dibasic)
Total Chlorine Reagent Powder Pillow to the second tube. To
open the powder pillow, tap the bottom of the packet on a hard
surface, tear open the packet along the dashed line, open the packet
and form a spout by squeezing the side edges, and pour the
contents into the sample. (Note: Check reagent accuracy of each
new lot of DPD Total Chlorine Reagent Powder Pillows. See
10.13).

10.12.6	Cap the second tube and swirl to mix. Accuracy of the test is not
affected by undissolved powder.

10.12.7	Wait 3 minutes. The result of the test must be read within 6
minutes of the addition of the powder.

10.12.8	Place the second tube in the top right opening of the color
comparator. Hold the comparator up to a light source such as a
window or lamp. Look through the openings in the front of the
comparator.

10.12.9	Rotate the color disc until the color matches in the two openings.

10.12.10	Read the mg/L total chlorine in the scale window. Record the
mg/L total chlorine on the Total Chlorine Residual of Purified


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Water form (see 16.2).

10.12.11	Rinse the viewing tubes several times with de-ionized water and
allow to dry before putting them back in the kit.

10.12.12	Return the color disc to its plastic storage envelope.

10.13 Accuracy check of each new lot of DPP. -When a new lot of DPD Powder

Pillows is received, conduct the following test prior to using the DPD Powder

Pillows to monitor the total chlorine residual of the laboratory's deionized water

(see 10.12).

10.13.1	Clean two beakers and the kit's plastic viewing tubes and caps
with isopropyl alcohol or a non-abrasive detergent prior to
commencing the test. Rinse several times with deionized water
(from the Barnstead B-Pure filtration unit on the north wall of
room B206). Use a soft cloth for wiping or drying the plastic
viewing tubes. Do not use paper towels or tissue as this may
scratch the plastic.

10.13.2	In a beaker, collect approximately 100 mL sample water from the
Barnstead B-Pure filtration unit on the north wall of room B206.
Pour water from the beaker into one plastic viewing tube until the
water level reaches the first line (bottom edge of the frosted area-
equals 5 mL). This is the blank.

10.13.3	Cap the blank and place it in the top left opening of the color
comparator (containing color disc).

10.13.4	Snap open an ampule of the Chlorine Standard Solution, (50-75
mg/L, 2-mL PourRite ampule). Note the amount of free chlorine
at the time that the ampules were filled. This value can be found
on the first page of the instructions accompanying the chlorine
standard.

10.13.5	Prepare a dilution of the standard to yield anywhere from 1 to 3
mg/L free chlorine. For example, if the amount of free chlorine in
the standard is 64.2 mg/L, adding 1 mL of the chlorine standard to
49 mL water will yield a water sample with approximately 1.3
mg/L chlorine (calculation: [64.2 mg/L][l mL]=[X mg/L][50 mL];
solving for X yields X=1.28 mg/L). Using a sterile 25 mL pipet,
pipet 49 mL of water from the beaker and add it to a second, empty
beaker. Using a sterile 1 mL pipet, add 1 mL of the chlorine


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standard to the 49 mL of water. Swirl to mix.

10.13.6	Fill the second plastic viewing tube to the first line (bottom edge of
the frosted area) with chlorinated water from the second beaker.

10.13.7	Add the contents of one DPD Total Chlorine Reagent Powder
Pillow to the second tube. To open the powder pillow, tap the
bottom of the packet on a hard surface, tear open the packet along
the dashed line, open the packet and form a spout by squeezing the
side edges, and pour the contents into the sample.

10.13.8	Cap the second tube and swirl to mix. Accuracy of the test is not
affected by undissolved powder.

10.13.9	Wait 3 minutes. The result of the test must be read within 6
minutes of the addition of the powder.

10.13.10	Place the second tube in the top right opening of the color
comparator. Hold the comparator up to a light source such as a
window or lamp. Look through the openings in the front of the
comparator.

10.13.11	Rotate the color disc until the color matches in the two openings.

10.13.12	Read the mg/L total chlorine in the scale window. The mg/L total
chlorine read from the color comparator must approximate the
chlorine concentration (mg/L) in the prepared dilution in order for
the reagents to be used in the total chlorine residual test.

10.13.13	Record the results in the DPD Reagent Accuracy Form (see 16.1).

10.13.14	Discard the remaining chlorine standard in the ampule by pouring
it down the sink. Rinse the ampule with water and place it in a box
for broken glass.

10.13.15	Rinse the viewing tubes several times with deionized water and
allow to dry before putting them back in the kit.

10.13.16	Return the color disc to its plastic storage envelope.

11.0 DATA ANALYSIS/CALCULATIONS:

11.1 When the report of water sample analysis is received from the vendor laboratory,


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SOP No. QC-01-05
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record the testing results legibly and in indelible ink under the "Test Results"
column of form 16.3, Quality Assurance of Purified Water Form. Compare the
testing results with the "Accepted Limits". For each parameter, if the testing
results for that parameter fall within the accepted limits, indicate in form 16.3 that
the water quality is acceptable. If the testing results for that parameter fall outside
of the accepted limits, indicate that the water quality is not acceptable, and record
the corrective action taken (see section 14.0).

11.2	Record the results of the total chlorine residual test in the Quality Assurance of
Purified Water Form (see 16.3). Compare the testing results with the "Accepted
Limits". If the testing results fall within the accepted limits, indicate in form 16.3
that the water quality is acceptable. If the testing results fall outside of the
accepted limits, indicate that the water quality is not acceptable, and record the
corrective action taken (see section 14.0).

11.3	The water quality is acceptable only if the results for all parameters fall within the
accepted limits.

12.0 DATA MANAGEMENT/RECORDS MANAGEMENT:

12.1	The reports of water sample analysis must be placed in the Quality Assurance of
Purified Water Record Book along with the carbon copy of the vendor chain of
custody form.

12.2	Data will be recorded promptly, legibly, and in indelible ink on all forms (see
16.0). The forms will be kept in the Quality Assurance of Purified Water Record
Book. The Record Book is kept in a secured file cabinet in the file room D217.
Archived data is subject to OPP's official retention schedule contained in SOP
ADM-03, Records and Archives.

13.0 QUALITY CONTROL: None

14.0 NONCONFORMANCE AND CORRECTIVE ACTION:

14.1	If the water quality, including residual chlorine, falls outside of acceptable limits
take corrective actions and retest the water to demonstrate that the water quality
parameter(s) that previously fell outside of acceptable limits is/are now within
acceptable limits.

14.2	Disinfectant efficacy tests may have been performed between the time the water
quality fell outside of acceptable limits (i.e., potentially one day after the date of
the previous sampling for that test parameter) and the time that results of
successful retesting are received. If the media and reagent controls associated


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with each test indicate that the media and reagents perform(ed) acceptably, the
test data are considered valid.

14.3 Refer to Table 3 below for examples of corrective measures to take if water
quality parameters fall outside of the acceptable limits:

Table 3. Water quality parameters and suggested corrective measures.

Parameter

Suggested Corrective Measures

Heavy Metals, Total

Replace the cartridges in the B-pure Pressure Cartridge System.
See ref. 15.1

Heavy Metals, Single
(Cd, Cr, Cu, Ni, Pb, and Zn)

Replace cartridges in the B-pure Pressure Cartridge System. See
ref. 15.1

Total Organic Carbon

Replace the cartridges in the B-pure Pressure Cartridge System.
See ref. 15.1

Conductivity/Resistivity

Replace the cartridges in the B-pure Pressure Cartridge System.
See ref. 15.1

Heterotrophic Plate Counts

Replace the final filter in the B-pure Pressure Cartridge System.
See ref. 15.1

Water Quality (or Water
Suitability) Test

Replace the cartridges in the B-pure Pressure Cartridge System.
See ref. 15.1

14.4 If the corrective measures in 14.3 have been taken and retesting demonstrates that
the water quality parameter(s) that previously fell outside of acceptable limits
continue to fall outside of acceptable limits, take one or more of the following
courses of action:

14.4.1	Discuss the problem with the Facility Operation Branch
Mechanical Engineer (410-305-4357). The problem may stem
from the Environmental Science Center's deionized water system,
which is the feedwater for the Barnstead B-pure Pressure Cartridge
System filtration unit. Retest the water following any corrective
measures taken by the Facility Operation Branch Mechanical
Engineer.

14.4.2	Consult with Region III scientists to determine if they have
experienced a similar problem. Retest the water following any
corrective measures taken.

14.4.3	Call the vendor laboratory and seek advice from technical staff.
Retest the water following any corrective measures taken.

15.0 REFERENCES:

15.1 Barnstead B-pure Pressure Cartridge System Operation Manual and Parts List,


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Series 583.

15.2	Eaton, A.D., Clesceri, L.S., Rice, E.W., Greenberg, A.E. eds. Standard Methods
for the Examination of Water and Wastewater, Online Edition. American Public
Health Association, American Water Works Association, Water Environment
Federation, Section 9020 approved 2005.

15.3	U.S. EPA Region III and OPPTS Environmental Science Center Specifications,
Volume 2, November 7, 1996.

16.0 FORMS AND DATA SHEETS:

16.1	DPD Reagent Accuracy F orm

16.2	Total Chlorine Residual of Purified Water Form

16.3	Quality Assurance of Purified Water Form

16.4 Purified Water Resistivity Record Form


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16.1 DPD* Reagent Accuracy Form
OPP Microbiology Laboratory

DPD Reagent Accuracy Form

Dale

Time

Initials

Lot
Number
ofDPD
Powder
Pillows

Date
DPD
Powder
Pillows
Rcvd

Dilution

Chlorine
Cone, of
dilution as
determined
bv Hach Kit

Test Kit Reagents
Acceptable?

Ampule
Chlorine

Cone.
(mg/L)

Amount
Chlorine
Sid (niL)

Amount

Water
(mL)

Chlorine
Cone, in
Dilution

(mg/L)

YES

NO





























































































































































































































*DPD=salt of N,N-Diethyl-p-Phenylenediamine Potassium Iodide Sodium Phosphate, Dibasic


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16.2 Total Chlorine Residual of Purified Water Form
OPP Microbiology Laboratory

TOTAL CHLORINE RESIDUAL OF PURIFIED WATER FORM

Date

Time

Initials

Total Chlorine (mg/L)










































































































































































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16.3 Quality Assurance of Purified Water Form
OPP Microbiology Laboratory

QUALITY ASSURANCE OF PURIFIED WATER FORM

Month/Year



Initials



Parameters**

Accepted Limits

Test Results

Acceptable?

Corrective Action
Taken

Yes

No

Heavy Metals. Total

.< 0.10 mg/L









Heavy Metals. Single:
Chromium

< 0.05 mg/L









Copper

< 0.05 mg/L









Nickel

< 0.05 mg/L









Zinc

< 0.05 mg/L









Cadmium

< 0.05 mg/L









Lead

< 0.05 mg/L









Total Organic Carbon

<1.0 mg/L









Conductivity

<2 umhos/cm at
25EC









Total Chlorine
Residual

<0.1 mg/L*









Heterotrophic Plate
Counts

< 500 CFU/mL









Water Quality (or
Water Suitability)

Test

0.8 to 3.0 ratio









*As detected by Hach Total Chlorine Test Kit (0.0-3.5 mg/L)

**Heavy metals analyses and the Water Quality Test are performed annually.


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16.4 Purified Water Resistivity Record Form
OPP Microbiology Laboratory

PURIFIED WATER RESISTIVITY RECORD

Date

Time

Initials

Resistivity Meter

Reading
(megohms-cm)

Actions Taken










































































































































































































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