Water Quality Chemistry Shakoora Azimi-Gaylon State Water Board

Water Quality Chemistry
Shakoora Azimi-Gaylon
State Water Board
Water Quality Chemistry
•
•
•
•
Introduction
Objectives
Logistics
Agenda: Course topics
Course Topics (Day 1)
FIELD SAMPLING AND TESTING
Introduction
purpose of sample collection
monitoring data should answer questions asked
in the monitoring plan
Sampling Design
– when and where to collect samples
– frequency of monitoring
Course Topics (Day 1)
FIELD SAMPLING AND TESTING cont.
Field Sampling and Quality Assurance
– Field & Sampling preparation
• Sample containers and preservatives
– appropriate sample containers
– maintaining appropriate sample
temperature and sample hold time
– Chemical Preservation
• Chain of custody record
• Field quality control
• Field testing
Course Topics (Day 1 & 2)
DATA QUALITY OBJECTIVES
Monitoring program must have a data quality
objective
Precision
Accuracy
Representative
Completeness
Comparability
Course Topics (Day 2)
LABORATORY ANALYSES
 Introduction
 Laboratory Accreditation
 Quality assurance program
 PE samples
 Wastewater Treatment Plant Operator
Certification
 Sample receiving and preparation






Laboratory automation
Standard Operating Procedures (SOP)
Staff training
Laboratory equipment
Standards (solvents)
Quality control samples
Course Topics (Day 2)
LABORATORY DATA
 Laboratory Data Collection and Results
 Staff qualification
 Instrumentation
 Standard procedures
 Calculating final data
 External or internal standard
 Review and approval of final data
 Quality Assurance Check
 Independent of lab business and operation
 Procedure for rejecting data and re-analyses when QA fails
Course Topics (Day 2)
DATA VALIDATION
 Evaluation of sample and data from time of
collection to reporting
 Correct sample collected?
 Correct sample analyzed?
 Correct methods (standard) used to identify the pollutant (s)
of concern?
 Quality Assurance Program and QC Samples
 QA review to verify the results reported independent of lab
business and operation- qualifiers are used
 Quality control samples met the acceptance criteria?
Course Topics (Day 2)
HOW TO READ THE DATA
– Don’t just read the reported pollutant
concentration
– Is the correct chemical or pollutant
analyzed?
– What is the unit of measurement?
– What is the lab reporting limits (detection
& quantitation)?
Water Quality Chemistry
COURSE OBJECTIVES:
• Learn the basic field sampling and laboratory
protocols
– learn the water quality sampling procedure
– learn how to read laboratory data
• when inspecting the sampling site
• when reviewing the data
Field Sampling and Testing
• Sample Collection
– Why samples are needed
– What questions need to be answered
• When to collect samples
• Where to collect samples
• How much to collect
Field Sampling and Testing
• Sampling Design
– Why is selecting an appropriate sampling
design important?
• The sampling design is a fundamental part of
data collection
• A well-developed sampling design ensure that
data are sufficient to draw conclusions
Field Sampling and Testing
• Sampling Design Cont.
• Appropriate sampling design helps in
generating accurate information about the
level of contamination in the environment
Field Sampling and Testing
• Sampling Design Cont.
• When designing a sampling plan consider the
following elements in relate to the study objective:
» sample location, sampling time and frequency
of sampling,
» the appropriateness and accuracy of the sample
collection and handling method,
» the quality and appropriateness of the
laboratory analysis, and
» the representativeness of the data collected
with respect to the objective of the study
Representativeness
• Representativeness should be addressed
through the sampling design
– Sample is representative of the environment
– Sample concentration is representative of the level
of contamination
• To determine the water quality impairment the
following information may be needed:
– variation in seasons
– variations at sampling points
– the amount of pollutant & extent of contamination
Representativeness
Accurate Information
Representativeness
• Developing a sampling design is a critical
step
– defensible data is needed for developing
regulatory tools
– data needed to investigate a problem
Sampling Designs
Two main categories of sampling designs
1) Probability-based
designs
2) Judgmental sampling
designs
Probabilistic and Judgmental
Sampling Designs
 Probabilistic Random Sampling Design
 apply sampling theory
 involve random selection of sampling
 Judgmental Sampling Design
 involve the selection of sampling units on the
basis of expert knowledge or professional
judgment
Probability-based versus
Judgmental Sampling Designs
Probability-based
Judgmental
• Provides ability to calculate
uncertainty associated with
estimates
• Provides reproducible results
within uncertainty limits
• Provides ability to make statistical
inferences
•Can be less expensive
than probabilistic designs
• Can be very efficient with
knowledge of the site
• Easy to implement
Disadvantages • Random locations may be difficult
to locate
• An optimal design depends on an
accurate conceptual model
•Depends upon expert
knowledge
• Cannot reliably evaluate
precision of estimates
• Depends on personal
judgment to interpret data
relative to study objectives
Advantages
What do you need to do?
• What are the objectives of the sampling
design process?
– The sampling design process should match the
needs of the project with the available resources
– when and where to collect samples
• If seasonal variation
• If temporal and spatial
– frequency of monitoring
Field Sampling and Testing
Field Sampling and Quality
Assurance
• Sample containers and
preservatives
• Chain of custody record
• Field quality control
samples
• Field testing
Field Sampling Quality Assurance
Field and Sample preparation
• Sample containers and preservatives
– Glass, polyethylene or others
– Keeping samples at prescribed temperature
– Use of chemical preservatives and prescribed
temperature
• Sample holding time
– Degradation of chemicals
– Regulatory requirements
Field Sampling Quality Assurance
Sample preservation
• Methods of preservation are relatively limited
• Preservation achieve the following:
– retard hydrolysis of chemical compounds and
complexes,
– retard biological action,
– reduce volatility of constituents, and
– reduce absorption effects.
– preservation methods are generally limited to pH
control, chemical addition, refrigeration, and freezing.
Field Sampling Quality Assurance
• Field sampling
Sampling procedures
• Integrated sampling
– To represent average concentration
• Composite sampling
– A sample of material which is obtained by blending
two or more individual samples
• Grab
– A sample collected at a specific time and specific
location, used to determine the nature of the water
for that specific time and location only
Mercury Low Level Sampling
• EPA Method 1669: Sampling Ambient
Water for Trace Metals at EPA Water
Quality Criteria Levels
• Known as the “Clean hands, Dirty
Hands”sample collection technique
• Use An ultra-clean sample collection
technique
• Two-Person Sample Collection
Mercury Low Level Sampling
• Equipment:
– 1000-ml Teflon Beaker Dipper with 6-foot handle
• Supplies:
–
–
–
–
–
TyvekSuits
Standard Gloves
Shoulder Length Gloves
40 ml VOA Vials
Cooler for Sample Transportation
Mercury Low Level sampling
• Sample Collection Procedure
• Two Samplers are required
1. “Clean Hands”sampler
2. “Dirty Hands”sampler
• The bottom two feet of the Teflon dipper (near the
beaker) and the 40 ml sample vials are pre-cleaned at the
laboratory and double-bagged prior to the sample
collection event
Mercury Low Level Sampling
• Both samplers put on PPE
– Tyveksuits
– Shoulder-length gloves
– Standard gloves
• Dirty handles the top of the Teflon dipper and removes
the outer bag
• Clean removes the inner bag and handles only the
pre-cleaned and double-bagged portion of the Teflon
dipper
Field Sampling Quality Assurance
• Field quality control samples
– Trip blank
– Field blank or equipment blank
– Field duplicate (split sample)
– Field spike (Matrix Spike)
• Procedure for spiking sample
Field Sampling Quality Assurance
• Trip Blank
– To check contamination during sample handling and shipment from
field to the laboratory
• Field Blank:
– To check cross contamination during sample collection, sample
shipment, and in the laboratory. Also to check sample containers
• Field Duplicate
– To check reproducibility of laboratory and field procedures. To
indicate non-homogeneity.
• Matrix Spike (Field spike)
– Required by laboratory’s contract to check accuracy and precision of
organic analyses.
Field Sampling Quality Assurance
• Trip Blank
– Every sampling trip
• Field Blank
– Every sampling day
• Field Duplicate
– One per 20 samples (5%)
• Matrix Spike (Field spike)
– One per 20 samples (5%) when required
Field Sampling Quality Assurance
• Chain of Custody Record
– Recording the correct information
 Pollutant specific instead of a method number or scan
 Sample preservation
 Date and time of sample collection
 Other appropriate communication with the laboratory
Field Sampling Quality Assurance
• Field Testing
– Field equipment
• Supplies
– Equipment calibration
– Record keeping
Field Testing
Procedure for basic field equipment
– At each station, turn the meter on and place the probe
into the water column
– Obtain the reading for each station
– Rinse the probe with distilled water
– Turn the meter off
– Be careful to handle the probe carefully so as not to
damage it while in the field
– Recheck the standard (calibration) at the end of the day
and record the reading
Field Testing
•
•
•
•
•
•
•
pH
Dissolved oxygen
Temperature
Conductivity/ TDS
Turbidity
Chlorine
Nitrate, nitrite, ammonia nitrogen
Field Testing
• pH
– pH, "potential of hydrogen", is a measure of the concentration
of hydrogen ion in the water
– pH measurement indicates the acidity or alkalinity of the water
– On the pH scale of 0-14, a reading of 7 is considered to be
"neutral“
– Naturally occurring fresh waters have a pH range between 6
and 8
– pH of the water affects the solubility and availability of nutrients,
and how they can be utilized by aquatic organisms
Testing pH Level
Field Testing
• Dissolved Oxygen
• DO is the amount of oxygen dissolved in water,
measured in milligrams per liter (mg/L)
– DO in water is critical to the survival of various
aquatic life in streams, such as fish
– The ability of water to hold oxygen in solution is
inversely proportional to the temperature of the
water
Dissolved Oxygen
• Dissolved Oxygen (dissolved gas)
decreased as temperature increased in the
Ocean
Field Testing
• Temperature
• Temperature is a measure of how cool or
how warm the water is
• expressed in degrees Celsius (C).
• critical water quality parameter
• directly influences the amount of dissolved oxygen
that is available to aquatic organisms.
• water temperature that exceeds 18 degrees
Celsius has a deleterious effect on several fish
species in streams.
• Salmonids, for example, prefer waters of
approximately 12 to 14 degrees Celsius
Field Testing
• Temperature
• Temperature of Cold and Warm waters not to
increase more than 5 degree (F)
• After taking the pH reading from the pH meter, obtain
the temperature reading at each station and record it
on the data sheet.
• Place the thermometer or pH meter in the water column.
• After the reading stabilizes, record it on the data
sheet.
Field Testing
• Conductivity
Conductivity is the ability of the water to
conduct an electrical current
• an indirect measure of the ion concentration.
– The more ions present, the more electricity can be
conducted by the water.
– This measurement is expressed in microsiemens per
centimeter (uS/cm) at 25 degrees Celsius.
Total Dissolved Solid
• Total dissolved solids is a measure of the
amount of particulate solids that are in
solution.
• TDS shall not exceed 125 mg/l
• This is an indicator of nonpoint source
pollution problems associated with various
land use practices.
• The TDS measurement is expressed in
(mg/L).
Turbidity
• Turbidity is a measure of the clarity of the
water.
• Turbidity is the amount of solids suspended in
the water.
• Turbidity can be in the form of minerals or
organic matter.
• Turbidity is a measure of the light scattering
properties of water, thus an increase in the
amount of suspended solid particles may be
visually described as cloudiness or
muddiness.
• Turbidity is measured in Nephelometric
Turbidity Units (NTU).
Field Testing
• Turbidity
• Where natural turbidity is between 0 and 5
NTU's, increase shall not exceed 1 NTU
• Equipment- Turbidity Meter Kit, sterile tissues
(kimwipes), distilled water, and data sheet.
• Using a clean sterile , empty water bottle
unscrew the cap
• DO NOT touch the inside of the bottle, nor the
inside of the cap. It should remain as sterile as is
possible.
• With the cap off the bottle, turn the bottle upside
down and place the open end into the column of
water.
Field Testing
• Turbidity
• With the bottle upside down in the water column,
turn the bottle to face upstream to fill with stream
water.
• Bring the bottle back out of the water column and
secure the cap.
• While preparing the turbidity meter for use, let the
turbidity sample bottles adjust to room
temperature
Field Testing
• Chlorine
Two methods are recognized by the EPA for
mandated testing on wastewater discharge:
– DPD and the Ion Selective Electrode (ISE)
method.
– Because of the fragility of the sample
conditions, these tests are most accurate when
done on site.
– DPD is a colorimetric method, and is affected
by turbidity and color in the sample, scratches
on the sample vial, and stray sunlight.
– The ISE method is unaffected by these issues,
making it an accurate as well as convenient
method to make these measurements in the
field.
Residual Chlorine
• The amount of measurable chlorine remaining after
treating the water with chlorine
• There are 3 primary types of chlorine residual
– Free Residual - Strong disinfecting power, relatively
unstable
– Combined Residual - Weak disinfecting power, relatively
stable
– Total Residual - Free Residual + Combined Residual
– Surface water may have free and/or some combined
residuals.
– Wastewater have combined and free residuals, depending
on the treatment process.
Chlorine Residual
• The most common field test method for determining
chlorine residual concentration is the (N,N-diethyl-pphenylenediamine) DPD Colorimetric
– Using DPD Colorimetric, DPD is added to a sample
and, through a series of reactions, a chemical is
produced that is red in color.
– The color intensity correlates to the residual chlorine
concentration
• A spectrophotometer is used to measure this intensity of
the red color
• For a quick non-NPDES check, the sample’s color is
compared to DPD- specific color wheel to determine
chlorine concentration.
– The easiest method to use
– But it is affected by a number of interferences, most
notably color, turbidity, and oxidizing agents.
Conventional Parameters
•Biological Oxygen Demand (BOD)
• BOD is a measure of how much oxygen is used
by microorganisms in the aerobic oxidation
• Usually, the higher the amount of organic
material found in the stream, the more oxygen is
used for aerobic oxidation.
• This depletes the amount of dissolved oxygen
available to other aquatic life.
• BOD measurement is obtained over a period of
five days, and is expressed in mg/L.
Biological Oxygen Demand (BOD)
• No
Standard for BOD 5-day.
• Equipment Needed: BOD Bottles, various
reagents, 250mL graduated cylinder, 25mL
buret, 2 droppers, and data sheet.
Biological Oxygen Demand (BOD)
Field sampling
• Collect a water sample in a clean 300mL glassstoppered BOD bottle.
• Add one Sulfate Powder Pillow and one Alkaline
Iodide-Azide Reagent Powder Pillow.
• Insert the stopper immediately into the bottle so that
no air is trapped in the bottle. Invert several times to
mix.
• Wait for the precipitate (floc) to form in the solution
and settle. Again invert the bottle several times and
wait until the floc has settled.
• Remove the stopper and add one Sulfamic Acid
Powder Pillow. Replace the stopper without trapping
air bubbles, and invert to mix several times.
Biological Oxygen Demand (BOD)
Field Sampling Cont.
• Pour the prepared sample into a 250mL graduated
cylinder to the 200mL mark
• Pour the contents of the graduated cylinder into a 250mL
erlenmeyer flask.
• Fill a 25mL buret to the zero mark with PAO Titrant,
0.025 N
• Titrate the prepared sample with PAO Titrant to a pale
yellow color, and record the number of mL used
• Add two droppers full of Starch Indicator Solution and
swirl to mix
• Continue the titration until the solution changes color
from dark blue to colorless, and record the number of mL
used
Bacteriological Test
• A bacteriological test shows if water is free from
disease-causing bacteria
• It is possible to test for virtually every water-borne
disease-causing bacteria and virus, but such a test
would be costly
• The most common test is total coliform bacteria
– Because coliform bacteria commonly inhabits the
gastrointestinal tract of warm-blooded animals,
– They serve as indicators of fecal contamination and
as a marker for other, possibly pathogenic
microorganisms
Flow measurement
• When monitoring water quality, a flow measurement
should be obtained.
• Follow the manufacturer's instructions and calibrate the
flow meter.
• Determine where to take the flow measurement in the
stream
– Do not take the measurement in a pool.
– Take the measurement in a riffle or the tail out of a pool.
– The cross section of stream should be fairly uniform in
depths across the section you will measure.
– There should be no major obstructions upstream or
downstream of where the measurement is taken.
– Remove any movable obstructions from the stream such
as debris, leaves, large rocks, sticks, etc. that would
disrupt the flow or divert the flow of the stream.
Flow measurement
• There should be enough water to submerge the
flow meter
– If there is no available water at the station, for example, the
water has gone subsurface, record this observation on the
data sheets.
• Spread the measuring tape out from left stream
bank to right stream bank.
• The tape should be secured above the surface of
the water on each bank and pulled taught.
• The tape should be within the wetted perimeter of
the stream.
• Record the entire width distance from left to right
bank on the data sheet. Leave the tape in place.
Flow Measurement
• Prepare the flow meter for use.
• Depending on the width of the stream, determine the
increments across the width of the stream to obtain
an accurate flow measurement.
– Approximately 10 to 20 measurements may be
necessary for accurate recordings of flows.
– Increments should be equal distances apart. At each
increment, record the tape value, or distance (width),
depth, and velocity.
Flow measurement
• To begin, read the measuring tape out to where the
water starts from the bank and record the distance.
– If there is no water at this distance record "no flow" on
data sheet.
– Take the first flow measurement at the edge of the
bank where the bank meets the water, and record the
flow data.
– This will be your second width distance recording, but
probably your first depth, and velocity measurement.
– Record all flow measurements on data sheet.
• Proceed across the width of the stream recording
the distance, depth, and velocity (as above) until
you reach the other bank.
Flow Measurement
• When all flow data has been collected, reel up
the measuring tape, secure all equipment, and
travel to next station.
• The actual discharge factor will be derived at the
office with the use of a calculator and discharge
formula.
Questions?
Why Field Testing?
• Water samples are in a chemically
dynamic state chemical, biological,
and/or physical processes change their
compositions
• Analyte concentrations may become
altered due to volatilization, sorption,
diffusion, precipitation, hydrolysis,
oxidation, and photochemical and
microbiological effects
Field Measurements
• Choosing Appropriate Field
Methods
– Each method has advantages and
disadvantages
– Inexpensive and easy-to-use methods are
usually not as accurate, while highly
accurate methods often cost more
– Select a method that fits the goals of your
water quality project
Field Instrument
• Field instruments are portable batterypowered instruments
– with a probe that can be dropped into a stream to
get a digital water quality reading
• These instruments are relatively easy to use
and are moderately expensive
– Once purchased they can be used over and over,
and in the long run are cheaper than test kits
when measuring a large quantity of samples
• Field instruments are available for limited
water quality parameters
– dissolved oxygen, pH, temperature, and
conductivity and other conventional parameters.
Field Instrument
• Significant Advantage
– can be used directly in the stream or river, thus
avoiding errors that occur when you handle samples
• when collecting a dissolved oxygen sample must be
very careful not to trap extra air bubbles in the sample
bottle
• Using a dissolved oxygen
• field equipment
– can simply drop the probe
into the river and get a direct
reading of dissolved oxygen
Field Test Kits
• Field test kits can measure water
quality in the field and require very
little training or equipment
• The exact methods vary, but most
involve adding tablets to a 5- to 10milliliter water sample
– The tablet contains a chemical that reacts
with the water sample, causing it to change
color after a short period of time
– The concentration of the chemical is then
shown by the intensity of the color
Field Test Kits
• These test kits are great teaching tools, but
are too imprecise and inaccurate for
detailed scientific studies
– difficult to get repeatable results, since different
people will see different colors depending on their
eyesight and the amount of light
• Field test kits are most often used for
educational monitoring and as a quick way
to identify gross water quality problems
– not appropriate for studies designed to measure
changes in water quality or to check if a water
body is meeting water quality standards.
Field Testing Training
• Multiparameter sensor instruments
provide reliable data for baseline water
quality studies
–
–
–
–
–
Easy to use in the field
Calibration capability
Store the data
Most are portable
If calibrated and used correctly, produce
reliable and reproducible data
Colorimetric Analysis
• Colorimetric – the measurement of color
– Technique used to evaluate an unknown
color in reference to known colors
– The intensity of the color from the reaction
is mostly proportional to the concentration
of the substance
• Accurate results are limited by eyesight or
inconsistency in the light source
• To eliminate inconsistencies a colorimeter can
be used to photoelectrically measure the
amount of colored light absorbed by a colored
sample in reference to a colorless sample
(blank)
Course Topics (Day 1 & 2)
Data Quality Objectives
• Monitoring program must have a data quality
objective
–
–
–
–
–
Precision
Accuracy
Representative
Completeness
Comparability
Course Topics (Day 2)
LABORATORY ANALYSES
 Introduction
 Laboratory Accreditation Certification
 Quality assurance program
 PE samples
 Wastewater Operator Certification
 Sample receiving and preparation
 Laboratory automation
 Standard Operating Procedures (SOP)
 Staff training
 Laboratory equipment
 Standards (solvents)
 Quality control samples
Course Topics (Day 2)
LABORATORY DATA
 Laboratory Data Collection and Results
 Staff qualification
 Instrumentation
 Standard procedures
 Calculating final data
 External or internal standard
 Review and approval of final data
 Quality Assurance Check
 Independent of lab business and operation
 Procedure for rejecting data and re-analyses when QA fails
Field Instrument
• These instruments are accurate if they are
calibrated frequently
– Calibration is done by checking the meter against
a sample with a known concentration of chemical
being measured (standard solution)
• If the instrument reading is in error, the
instrument is adjusted to match the correct
value
– Calibration should be done using a range of
standard solution concentrations, to ensure that
the instrument reads both low and high
concentrations correctly
Course Topics (Day 2)
DATA VALIDATION
 Evaluation of sample and data from time of collection to
reporting
 Correct sample collected?
 Correct sample analyzed?
 Correct methods (standard) used to identify the pollutant (s) of
concern?
 Quality Assurance Program and QC Samples
 QA review to verify the results reported independent of lab
business and operation- qualifiers are used
 Quality control samples met the acceptance criteria?
Course Topics (Day 2)
HOW TO READ THE DATA
– Don’t just read the reported pollutant concentration.
– Is the same pollutant listed on the report as listed on
COC?
– What is the unit of measurement?
– What is the lab reporting limits (detection &
quantitation)?
Data Quality Objectives
• Precision
• Accuracy
• Representative
• Completeness
• Comparability
Precision
• Precision is a measure of how reproducible the
data collected
– It determines the consistency of procedures for collecting
samples
– It determines the consistency of repeated samples that
are tested.
• Precision measurements are obtained by taking
duplicate samples each sampling day for each
parameter recorded.
– The samples should be taken at the same time and the
same place
– The relative percent difference will show how precise the
data is for the parameters sampled.
Accuracy
• Accuracy is a measure of confidence that the data
collected in the field and in the laboratory reflect the
true value of a given parameter.
• Each instrument will have various ranges of
expected values.
– for example, when calibrating the pH meter, a known pH buffer
solution of 7.0 will be sampled using the pH probe.
– If the value of the pH measured shows a reading of 8.1, the
difference between the average pH value is off, or biased, by
1.1 unit.
• Accuracy is a quantification of the difference
between the measured value and the true value.
Representative
• Representativeness is a measure of the extent to
which the measurements obtained actually depict
the true environmental condition being evaluated.
– for example, a sample taken near a manure spill
will not be indicative of the entire stream.
– Or samples taken from upstream location will not
be indicative of the water quality.
Completeness
• The completeness of data relies on how many
samples need to be taken to be able to use the
information that is collected.
– for example, when monitoring includes required
parameters at each of the fifteen stations plus a duplicate
sample at each station, if all samples are collected, the
completeness factor will have been met.
– however, should only 10 stations be sampled out of 15,
then the percent completeness would be approximately
67%.
– percent completeness is the number of planned
measurements judged valid divided by the total number
of measurements taken multiplied by 100.
Comparability
• Comparability can only be measured by data
gathered on the same stream or on a similar
stream with similar conditions.
– Data are compared for various reasons
– If the data is gathered over a period of two years,
the data may be compared on an annual basis
LABORATORY ANALYSES
Laboratory Procedure
Sample Analyses
Data Collection & Report
Generation
Reading and Reviewing
Laboratory Data
Laboratory Analyses
Laboratory Accreditation
 Certification
 Performance Evaluation (PE) samples
 Staff qualification and training
 Provision for utility owned lab
Wastewater Operator Certification (being certify as
wastewater operator is not sufficient lab analyses)
 Required by Water Code
Public wastewater treatment, public industrial treatment plant
Private wastewater or industrial plants, regulated by PUC
Private sewage plants with WDR
Sample receiving system
– Interpretation of chain of custody
– Tracking samples in the laboratory
– Sample storage
Utility Owned Laboratory
• Health & Safety Code: 100825
– Level of certification for utility owned lab
• Utility own lab staff certification
– Required for utility staff that conduct analyses
for compliance
– Certification offered by California Water
Environmental Association
– Apply to Lab Director and analysts
– Certification are specific to types of analyses
Certification
• Laboratory Accreditation
– Audit by DPH
– Qualification, instrumentations, procedures
• Wastewater Operator Certification
– Five level of operator certification
– Must meet the minimum experience and
education requirements and pass a written test
• Minimum experience requires depends on level
of certification
Laboratory Analyses
Sample Analyses
Standard procedure
Instrument calibration
Calculating sample results
Internal QA – frequency
Data collection and Report
Generation
Errors that can occur during
analysis
Laboratory Analyses
Reading laboratory data
Pollutants and concentration
Unit of measurement
Reporting limits
Qualifiers used by the laboratory
total vs. dissolved
non detect results
internal QA relation with data
Laboratory Analyses
• Laboratory Quality Assurance
• Internal Quality Control Samples
– Laboratory Standards
– Equipment blanks
• Extraction
• Analyses
– Laboratory Control Spikes
– Matrix Spikes
Laboratory Analyses
Data Validation
Begin with Chain of custody record
Is the correct pollutant analyzed?
Is correct sample analyzed?
Is the unit of measurement lower than
WQO?
Is result lower than reporting limits?
What does qualifier mean?
Does internal QA verify the data is
useable?
Laboratory Analyses
•
•
•
•
•
•
Volatile Organic
Pesticides
Petroleum Hydrocarbons
Metals
Mercury
Bacteria
Laboratory Analyses
• Volatile Organic
– Gas chromatograph Purge and
Trap
– Clean environment
– No headspace in samples
– Surrogates and Internal
Standards to check sample
recovery
Laboratory Analyses
• Pesticides
– Gas Chromatograph
– Sample extraction
– Surrogate added prior to extraction
Laboratory Analyses
• Petroleum
Hydrocarbons
– Sample extraction
– Gas chromatography
Analyses
– Multination peaks
– Fingerprinting
techniques
Laboratory Analyses
• Metals
– Sample digestion techniques
– Different laboratory instruments used
– Low level metals
Organic Analyses
Volatile Organic Analyses
QUESTIONS?