Download - WATER ASSESSMENT AND TESTING
WATER ASSESSMENT AND TESTING
Introduction to Watershed ScienceIntroduction to Watershed Science
Merritt CollegeMerritt College
Marc Epstein, InstructorMarc Epstein, Instructor
WATER MONITORING BASICS
Collection of Data Episodic (such as a spill) Synoptic (like snapshot day) Periodic and on a regular basis Continuous over long period of time
Consistent collection methods
ANALYSIS DEFINED
An investigation into whether a waterbody can support the beneficial uses assigned to it.
Water quality monitoring is commonly defined as the
sampling and analysis of water (lake, stream, river, estuary, or ocean) and conditions of the
waterbody.
TYPES OF MONITOING
Biological
Chemical
Physical
BIOLOGICAL Include measures related
to the plant and animal life of the water body, such as:
Fish species diversity and abundance;
Presence or absence of indicator fishes, aquatic invertebrates, or aquatic plants.
CHEMICAL
Include contaminants such as: Metals Dissolved nutrients Oils Pesticides
Chemical properties of the aquatic system such as: Dissolved oxygen Chemical oxygen demand Acid neutralizing capacity
PHYSICAL
Include general conditions such as: Temperature Flow Sediment characteristics Water color Within-channel habitat structure
WHAT IS KWEST MONITORING Total Maximum Daily Load (TMDL) A calculation of the maximum amount of a pollutant that a
waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources.
Water quality standards are set by States, Territories, and Tribes. They identify the uses for each waterbody, for example, drinking water supply, contact recreation (swimming), and aquatic life support (fishing), and the scientific criteria to support that use.
A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources.
The calculation must include a margin of safety to ensure that the waterbody can be used for the purposes the State has designated.
The calculation must also account for seasonal variation in water quality. (From federal Clean Water Act)
THE BASIC FIVE WATER QUALITY VITAL SIGNS
Temperature Dissolved Oxygen pH Conductivity and
Salinity Turbidity
TEMPERATURE Measure of average kinetic energy of water
molecules Affects water chemistry and aquatic organisms Influences: Amount of oxygen that can be dissolved Rate of photosynthesis Metabolic rate of organisms Sensitivity of organisms to toxic waste,
parasites, and diseases Timing of reproduction and migration of
organisms
Code(Note a)
Device Cost Labor Application Limitations Major sources of error
TR Bulb thermometers
$5-20 1 minute Air, Surface water, or sample in jar
Low resolution (0.5 C to 1 C)
Inaccurate setting by manufacturer, disconnection of capillary tube from scale, air bubbles in tube
TRM U-shaped Min-Max thermometer
$25 1 minute Air, incubation chambers
Low resolution (1 C). Not recommended for field use (mercury)
Inaccurate setting by manufacturer, disconnection of capillary tube from scale, air bubbles in tube, incomplete resetting
TT Digital Thermometer
$25 2 min Air, Surface water, inside soil or sediment
Needs batteries
Inaccurate setting by manufacturer, drift from original setting
TT Thermistor probes var Vertical gradients Response depends on length of cable
Inaccurate setting by manufacturer, drift from original setting
TH Hobo-Temperature Data loggers
$60-100
10 min (program) 10 min download, plus deployment labor
Continuous measurements of temperature in the environment
Requires use of computer, need to buy software
Inaccurate setting by manufacturer, drift from original setting
TTP Sonde/datalogger probe
~$4,000 for entire Sonde
1 min Discrete or continuous measurements
Requires use of computer, need to buy software
Inaccurate setting by manufacturer, drift from original setting
DISSOLVED OXYGEN
The amount of oxygen dissolved in water Aquatic organisms need oxygen to survive and grow
Consequences of insufficient dissolved oxygen: Death of adults and juveniles Reduction of growth Failure of eggs/larvae to survive Change of species in given water body
Code (Note a)
Principle
Device Resolution
(@range)
Cost(Note b)
Labor Limitations Extent of Error(Note c)
DOC Colorimetric
Reagent ampoules (Note c) and comparator (e.g., “CHEMets” by Chemetrics)
1 mg/l (1-6)2 mg/l (6-12)
$36/20 tests measure 3 min.
1 mg/l (1-4)2 mg/l (4-8)4 mg/l (8-12)
DOC Colorimetric
Reagent ampoules (Note d) and comparator (e.g., “AccuVac” by Hach)
0.2 mg/l (0-15)
$78/25 tests measure 3 min.
Leaky seal leads to continuous color development
1 mg/l
DOW Titrimetric Modified Winkler Method kit: DO bottle, reagents, vial and syringe for titration
0.2 mg/l (0-15)
$50 /100 tests measure 8 min.
“Sliding” endpoint.
0.5 mg/l
DOE Polarographic
D.O. meter+electrode 0.05-0.2 mg/l (0-20)
$800 prep/calib. 1 hmeasure 0.5-3 min.
Requires expertise and experience
5%
DOP Polarographic
Rapid-Pulse probe, for Sonde (e.g., YSI or Hydrolab)
0.1 mg/l (0-20)
~$4,000 for entire Sonde
prep/calib. 2 hDownload 1 hr
Requires expertise and experience
5%
pH Measure of acidic vs. basic – strength of
Hydrogen ion Lower value more acidic – Higher value
more alkaline Aquatic organisms require narrow pH Extreme pH damages fish gills,
exoskeleton, and fins Changes in pH may cause or change
chemical reactions
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Code (Note a)
Device Range Resolution (pH units)
Cost Labor Limitations Extent & Sources of Error (pH units)
PHLQ Liquid pH kit 2-10 2 $4 /50 tests
2 min Daylight only
2; Aging of indicator
PHLQ Liquid pH kit 5-10 0.5 $8 /50 tests
2 min Daylight only
1 Aging of indicator
PHST Universal pH strip (Note b)
1-14 1 $12 /100 tests
3 min Daylight only
1 Aging of indicator, slow response
PHST “Environmental” pH strip (Note b)
5-10 0.5 $12 /100 tests
3 min Daylight only
0.5 Aging of indicator, slow response
PHST “Physiological” pH strip (Note b)
6.5-10 0.3 $12 /100 tests
3 min Daylight only
0.3 Aging of indicator slow response r
PHEL Pocket meter with dry electrode
1-14 0.1 $60 10 min cal, 3 min measure
Need to rehydrate
0.3 Standard buffer drift, slow response
PHEL Multi-meter pH probe
1-14 0.1 variable 10 min cal, 3 min measure
0.3
PHP Sonde/datalogger probe
1-14 0.01 ~$4,000 for entire Sonde
10 min cal, 3 min measure
0.1
CONDUCTIVITY / SALINITY Conductivity is the ability of the water to conduct
electrical current Salinity is a measure of the amount of salts in
the water Salts (solids in dissolved form) break into
positively and negatively charged ions Conductivity and salinity increase with the
amount of salts in the water Salts affect the quality of water for drinking and
irrigation Various species have specific salinity tolerances
Code (Note a)
Principle Device Range Resolution Cost Labor Applications Extent & Sources of Error (percent of measured value)
EC Electrical conductance
Conductivity meter
0 to 200 microS
1 microS $60 2 min Snowmelt, rainwater
5% uncompensated temperature effectDrift, source of Standard
EC Electrical conductance
Conductivity meter
0 to1990 microS
10 microS $60 2 min Freshwater “
EC Electrical conductance
Conductivity meter
0 to19.90 miliS
100 microS (0.1 mS)
$60 2 min Freshwater, Brackish water
“
ECP Electrical conductance
Sonde/data logger probe
var var ~$4,000 for entire Sonde
2 min all 5% Drift, source of Standard
SAL Electrical conductance
Salinity probe
2 to 40 ppt(Note b)
varies Part of a package $800 or more
Brackish and Seawater
5%Drift, source of Standard
REF Refractive index
Refractometer
2-100 ppt(Note c)
1 or 2 ppt $150 1 min Brackish, Seawater,hypersaline ponds
10%
HYD Specific gravity
Hydrometer 16-40 ppt(Note d)
1 ppt $10 1 min Brackish and Seawater
10%
HYD Specific gravity
Hydrometer 2-100 ppt 1 ppt $30 (inc jar) 3 min Brackish, Seawater,hypersaline ponds
5
Gravimetric Total dissolved solids (TDS)
all 0.1 mg/l Lab method 5
TURBIDITY
Amount of suspended particles including Algae, suspended sediment, and organic matter
Suspended particles: Diffuse sunlight – reducing light Absorb heat – Increase temperature Clog fish gills Foul gravel beds Smother fish eggs and benthic insects
Code (Note a)
Principle Method name (Parameter, unit)
Cost Labor Application Limitation Extent & Sources of Error
Transparency Murkiness (Note b)
None 30 sec Turbidity watch, source ID
Not Applicable
SEC Transparency Secchi disk (Secchi depth, cm)
~$30 2 min Status of Lakes and pools
Need to deploy from above Daylight only
30%; Individual operator’s vision, Lighting, surface reflection, depth measurements
TRT Transparency Transparency tube (Transparency, cm)
$40 5 min Turbidity in streams Source ID
Daylight only 30%; Individual operator’s vision Length measurement, deposition
TUJ Transparency match
Dual cylinder (Jackson turbidity, JTU)
$40 5 min Turbidity in streams Source ID
Daylight only 40%; Individual operator’s vision, quality of standard, volume measurements
TUN Light-scattering Nephelometer (Turbidity, NTU)
$300 and up
10 min cal 1 min measure
Turbidity in streams and lakes, Source ID
Error variable, depending on instrument
TUN Light-scattering Automated Nephelometer (Turbidity, NTU)
$1000 and up
Installation, calibration, download.
Use with data logger and/or trigger, storm events
Fouling of light absorbing surfaces, drift from the calibrated state
TSS Gravimetric: Dry Weight per volume of sample aliquot (Note c)
Filtration for Total Suspended Solids (TSS, mg/l)
$2000 and up
20 min Sediment loads assessments
Requires laboratory facility
Error variable, depending on operating procedures
SSC Gravimetric: Dry Weight per volume (by water weight) of whole sample
Filtration for Suspended Sediment Concentration (SSC, mg/l)
$2000 and up
20-60 min Sediment loads assessments
Requires laboratory facility
Error variable, depending on operating procedures
IC Sinking Imhoff Cone Method
~$30 5 min (setup and read)
Finer Separation by density
Requires cones 30%; Lighting, surface identification, volume measurements
BEYOND THE FIVE BASIC VITAL SIGNS
Nitrogen Large amount introduced creates
excessive algal growth resulting in depleted dissolved oxygen
Phosphate When amounts become elevated algal
blooms can occur depleting dissolved oxygen
Bio-Assessment
Survey of benthic aquatic macro invertebrates
Survey of physical habitat