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Revised: 2/13/2016
NTUA LABORATORY SAMPLING PROCEDURES
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Revised: 2/13/2016
Wet Chemistry
Equipment Needed:





1 – 1L plastic bottle
Thermometer
pH-meter
Ice chest
Ice
Procedures:
1.)
2.)
3.)
4.)
5.)
6.)
Flush out the well/line for 5 minutes.
Write the collection date, collection time, PWSID#, system name,
sampler ID #, and tribal well number on the label and the chain of
custody.
Fill the 1-liter bottle completely with water from the well.
Take the temperature and a field pH reading of the water. Write the
temperature and pH reading on the label.
Put sample on ice. Keep sample at 4° C.
Submit sample to NTUA Laboratory immediately, within 24 hours.
The holding time for Wet Chemistry samples is 48 hours.
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Revised: 2/13/2016
Heavy Metals
Equipment Needed:
 1 – 1L plastic bottle with HNO3
Procedures:
1.)
2.)
3.)
4.)
5.)
Flush out the well/line for 5 minutes.
Write the collection date, collection time, PWSID#,
sampler ID#, system name, and tribal well number
on the bottle label and the chain of custody.
Carefully fill the 1-liter bottle containing HNO3 to the first
curvature/shoulder of the bottle with well water. Stand upwind of the
bottle containing HNO3. Do Not Inhale HNO3 Fumes.
Put the sample on ice. Keep sample at 4°C. There should only be one
bottle submitted.
Submit sample to NTUA Laboratory within 24-48 hours. The holding
time for Heavy Metals samples is 28 days- 6 months.
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Revised: 2/13/2016
Nitrate (NO3) & Nitrite (NO2)
(NTUA Laboratory Technique)
Equipment Needed:
 1 - 1Liter plastic bottle
Procedures:
1.)
2.)
3.)
4.)
5.)
6.)
Flush out the well/line for 5 minutes.
Write the collection date, collection time, system name, tribal well
number, sampler ID #, and PWSID# on the bottle label and the chain
of custody.
Completely fill the 1-L bottle with sample by forming a bubble-like
property over the rim of the bottle.
Carefully cap and close the 1-L bottle to seal out air bubbles (If air
bubble is present when the bottle is inverted, add a few more drops
of well water until no air bubbles are present).
Put the sample on ice. Keep sample at 4°C.
Submit sample to NTUA Laboratory within 24-48 hours. The holding
time for Nitrate is 28 days and Nitrite is 48 hours.
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Revised: 2/13/2016
Bacteriological
Equipment Needed:
 1 - 120ml sealed vessel w/Sodium
Thiosulfate
 NTUA Lab Bacteriological Form
 Ice
 Ice chest
 Temperature gauge
Procedure:
1.)
2.)
3.)
4.)
5.)
6.)
7.)
8.)
Remove any attachments such as hoses, filters, or aerators from
faucet. (See Note 1)
Flush line for 3-5 minutes.
Wash hands thoroughly prior to sampling.
Place temperature gauge at bottom of sink if sampling inside. If
outside hold temperature gauge under water and allow to stabilize.
Note: Never put the temperature gauge inside the vessel.
Complete NTUA Laboratory Bacteriological form (see attachment).
Remove seal and cap from vessel being careful not to touch the
inside of the cap or bottle. Note: Do not rinse out vessel or use
vessel if seal is broken.
Fill to the 100ml mark on vessel.
Cap bottle tightly and place in ice chest with ice. Keep sample below
10C.
The holding time for bacteriological samples is 30 hours.
NOTE 1: Avoid sampling from leaking faucets. If tap cleanliness is
questionable, a solution of 100-ppm sodium hypochlorite (about 10 ml or 2
teaspoons of household bleach per gallon of water) can be used to
disinfect the faucet before sampling.
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Revised: 2/13/2016
Fill form with black/blue ink pen only. No felt pens or pencils. Write legibly.
Section 1
Enter Public Water Supply Identification (PWSID) number, ex. NM 3039. Enter Site
number, ex. A-3.
Section 2
Enter company/district name, ex. NTUA Ft. Defiance. Enter address, telephone
number and responsible district code number.
Section 3
Check off box that corresponds with the type of analysis requested. For bacti
samples you will be checking off the first box for Total Coliform/E.Coli
Presence/Absence.
Section 4
Check off according to type of sample being collected. Options are: routine, new
customer, repeat, and other/special. If the sample is a repeat indicate if it is: at
site, upstream, downstream, or additional.
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Revised: 2/13/2016
Section 5
This section is for field results only. Temperature during collection is written in
space provided. If chlorine residual is also measured record on form in space
provided. If temperature was not measured give justification under detailed
description, ex. No temp gauge.
Section 6
Under Collected By enter sampler’s NTUA employee number, ex.1435. Enter
collection date, 04/10/02 or April 10, 2002. Enter time using military time, ex. 14:30
is 2:30 pm. Then enter town/extension where sample is collected, ex.
Crownpoint/Dalton Pass, Shiprock or Kayenta.
Section 7
Laboratory results are entered in this area. This is to be used by lab personnel
only.
Section 8
This section is used for owner’s name.
Section 9
This section is used for detailed description of sampling point. Example: meter
yoke, kitchen faucet, etc.
Section 10
This section is used for laboratory remarks and comments only. Please do not write
in this area.
IF YOU NEED TO MAKE ANY CORRECTIONS PLEASE STRIKE THROUGH
ERROR ONCE AND INITIAL, EX. KITCHEN JY. SAMPLER SHOULD BE THE
ONLY ONE TO MAKE CORRECTIONS. PLEASE BE SURE SECTIONS 1, 2, 3, 4,
5, 6, 8, and 9 ABOVE ARE FILLED OUT COMPLETELY.