FIELD WATER SAMPLING AND ANALYSIS: “GREEN LAKE”
OBJECT:
The object of this experiment is to learn correct sample collection and preservation methods.
These techniques will be used by the student later in the semester when doing independent
sampling.
When the experiment is complete the student should know:
• How to differentiate between the various types of samples
• How to use automatic sampling equipment
• How to collect and preserve a sample
• How to use a chain of custody form
DISCUSSION:
Sampling
The importance of correctly collecting a sample cannot be over emphasized. If the sample is
collected in an improper container, the wrong amount obtained, or the sample is improperly
preserved, the analytical results will be very poor and will be considered invalid. Prior to
sampling it is essential to research the type of container to be used, the volume necessary for a
valid sample, the type of (if any) preservation method to be used, and the maximum storage time
allowed. These parameters are listed in tables such as the Standard Method Table 1060:I
"Summary of Special Sampling or Handling Requirements".
In addition to the sampling parameters listed above, care must be taken to insure that the correct
type of sample is taken. The following is a list of the three most commonly used sample types:
• Grab - A sample that is collected in a body of water that is more or less homogenous.
The single sample can represent the much larger volume of water.
• Composite - A sample that mixes several grab samples that are obtained from the same
sampling point but are collected at different times. These samples are used when the content of
the water changes with time.
• Integrated - A sample that mixes grab samples collected at the same time but at different
points in the body of water. These samples are used when the content of the water varies with its
location in the body.
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When preparing to sample, a decision must be made whether to sample manually or
automatically. Manual sampling only requires the use of basic field equipment but may be costly
and time-consuming for large, long term projects because it is a labor intensive means of
sampling.
Automatic samplers can sample frequently and continuously. Initial cost of equipment may be
costly but in the long run can reduce the cost of labor, especially on long term projects. Care
must be taken to properly maintain and service any automatic samplers.
During the sampling process it is essential that established protocol be followed to insure the
accuracy and legitimacy of the sample. Established protocol also facilitates routine control of the
sample. The following is a list of the major points of sampling protocol and chain of custody
procedures that must be followed:
• Sample Labels - Label sample to prevent sample misidentification. Printed gummed
labels are ideal but something as simple as masking tape will be adequate. Include, at the
minimum, sample number, place, time, and date of collection. Sampler identification should also
be on the label.
• Sample Seals - Seal samples to protect sample from being tampered with from the time
of collection to the time of analysis. The seal should contain the same information as the label.
Attach the seal in such a way that it is necessary to break it in order to open the sample container.
• Field Log Book - Record all field data in a bound log book. At the minimum include:
purpose, time, date, location (sketch a map of area if one is not available), type of sample,
amount of sample, field observation ( weather, turbulence, etc.) sample number, names of people
in field, signature of samplers, as well as any other pertinent information. Accuracy is essential
when recording information in the log book. This information may need to be recalled several
years later and accurate notes will be much more reliable than the human memory.
• Chain-of-Custody Record - The chain-of-custody record keeps track of possession of the
sample from the time of collection to time of analysis. It should include sample number, time
date, and location of sample collection. It should also include signatures of people involved in
the chain of possession and the dates they possessed the sample.
• Sample Analysis Request Sheet - The sample analysis request sheet accompanies the
sample to the laboratory and includes the types of samples to be performed, name of person
receiving the sample, sample number and date.
• Receipt and Logging of Sample - In the laboratory, the condition and seal of the sample
are inspected. The label and seal are compared to the information listed on the chain-of-custody
record. The laboratory assigns the sample a number and stores it in a secured place until analysis.
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PRIOR TO ANY FIELD SAMPLING, SUFFICIENT TIME MUST BE TAKEN TO
ORGANIZE THE EQUIPMENT THAT MUST BE TAKEN TO THE FIELD. THIS
PROCESS OFTEN WILL TAKE MORE TIME THAN THE ACTUAL SAMPLING.
CARE MUST BE TAKEN TO ENSURE THAT ALL EQUIPMENT IS IN WORKING
CONDITION AND THAT ALL ACCESSORIES THAT MAY BE NEEDED FOR
CALIBRATION, ETC. ARE BROUGHT ALONG TO THE FIELD. DUPLICATES OF
EXPENDABLE ITEMS (BATTERIES, MEMBRANES, FILLING SOLUTIONS, ETC.)
SHOULD BE PACKED. A THOROUGH "CHECK-OFF' LIST EXPEDITES THIS
PROCESS.
EQUIPMENT (check-off list)
notebook and calculator
pen/pencil
bucket
dry cloth
misc. tools for repair
manuals
Conductivity Meter and probe
pH meter and electrode
DO meter and probe
HACH colorimeter
HACH digital titrator
Sample containers
Filtration device
Preservation material - cooler, acid
Labels and seals
Thermometers
Accessories - batteries, membranes, filling solutions, scissors
Log book, chain of custody record, sample analysis sheet
GPS
3
PROCEDURE
1.
2.
3.
4.
5.
6.
7.
8.
9.
Review check-off list
Proceed to Green Lake
Locate best area for measurements
Sketch a map of the area for future reference, record GPS coordinates
Review sampling types and methods
Perform sampling that can be done on site
Properly fill out sample labels and “chain of custody form”
Pack equipment for return trip
Inspect site prior to leaving to ensure nothing is left behind
TO BE TURNED IN: A business letter addressed to me stating the ‘who, what, where, when”
of the sampling. Included in the letter should be a brief description of 3 of the results (your
choice). As an attachment include the field worksheet notes, description of samples collected for
future analysis, completed chain of custody form, and any other pertinent information. For THIS
LAB ONLY , you do not have to list individual procedures followed.
4
Field Sampling
EENV 243 Fall 2019
SOP
Standard Methods for the Examination
of Water and Wastewater Samples
Table 1060 Collection and Preservation of
Samples
Westside soils
Superfund RI/FS
Green lake
Water parameters
Temperature
pH
Conductivity
Turbidity
Metals
Turbidity
Expression of the optical property of a
sample which causes light to be
scattered and absorbed rather than
transmitted.
Units are the Nephelometric Turbidity
Unit
(NTU)
Turbidity
Measures the reduction of transparency
in water due to suspended matter such
as clay, silt, or organic matter.
Causes problems with
Aesthetics
Filterabilty
Disinfection – primary for Env Eng
Turbidity - Disinfection
When turbidity is caused by organic matter,
many pathogenic organisms can be encased
in the organic particles
These particles can be resistant to chemical
disinfection
Therefore, the EPA has placed a a limit of
1 NTU as the maximum allowable in public
water supplies
COLORIMETERY
Works on the principle of light transmittance
to determine the concentration of various
water parameters.
Each parameter being analyzed requires a
specific light wavelength and specific
chemicals used for transmittance comparison.
COLORIMETERY
Procedure – Compare the light transmittance
of a ‘blank’ sample to the light transmittance
to a ‘chemically treated’ sample
HACH
Units
Most commonly mg/l or µg/l
SAMPLE TYPES
GRAB
COMPOSITE
INTEGRATED
SAMPLE “VARIABLES”
CONTAINER
SAMPLE SIZE
PRESERVATION
STORAGE
SAMPLING “PROTOCOL”
Sample Labels
Sample Seals
Field Log Book
Chain Of Custody Record
Sample Analysis Request Sheet
Receipt And Logging Of Sample
Labs –
Preferably Certified
Will Supply:
Labels
Seals
Chain – of – Custody
Sample and Analysis Request Sheet
Labs
May or may not supply:
Bottles
Cooler
Preservation material
Green Lake
https://www.google.com/maps/place
/46%C2%B000'28.4%22N+112%C2%B0
34'26.0%22W/@46.007892,112.573877,184m/data=!3m2!1e3!4b1!4
m2!3m1!1s0x0:0x0
Dress appropriately
Boots
Coat
Gloves
Hat
Purchase answer to see full
attachment