Groundwater Quality and Contaminants and Groundwater Investigation Flashcards
Water quality is determined by the
dissolved solutes and gases
suspended matter
Water quality is a consequence of the
natural physical and chemical state
alterations owing to human activities
what does TDS mean?
Total dissolved solids
what does TSS mean?
Total suspended solids
difference between TDS and TSS
TDS cannot be seen by the naked eye
is the total amount of
solids, in milligrams per liter, that remain when a water sample is evaporated to dryness
Total Dissolved Solids
unit for TDS
mg/L
1000 mg/L in ppm
1000 ppm
Classification of water based on TDS
Fresh = 0-1,000
Brackish = 1,000-10,000
Saline = 10,000-100,000
Brine = >100,000
it is the most important water quality parameter
TDS
t or f: dissolved gases are present in both surface and groundwater
t
most common dissolved gases in waters
Oxygen (O)
Carbon Dioxide (CO2)
Nitrogen (N)
Hydrogen Sulfide (H2S)
Methane (CH4)
occurs when the environment becomes enriched with nutrients, increasing the amount of plant and algae growth to estuaries and coastal waters
Eutrophication
common foreign substances during eutrophication
Nitrogen, Phosphorus, Potassium
brown water
sewage
black water
septage
degradation of water quality
due to human influences
anthropogenic effects
Groundwater contamination is
commonly marked by a ______
plume
A concentrated form of liquid contaminants
contamination plume
release pollutants from discrete conveyances.
Point sources
a combination of
pollutants from a large area
rather than from specific
identifiable sources
Nonpoint sources
Effects of Pumping
- Accelerates ground water flow to well
- Captures contamination within cone of depression
- May reverse ground water flow
- Can draw contamination up hill
- Will cause saltwater intrusion
t or f: freshwater is denser than saltwater
F
basis for future monitoring of waters
baseline data
Effects of water pollution
-Devastating to people and animals, fish, and birds.
-Unsuitable for drinking, recreation, agriculture, and industry.
-Destroys water life.
Challenges
Purpose
the act of collecting a portion of material for analytical purposes that accurately represents the material being sampled with respect to stated objectives
sampling
Pre sampling preparation
-alertness to representativeness
- plan to collect quality-control samples
- checklist of equipment
- review important information
- establish sample sites
-equipment calibration
-sampling information label
- selection of equipment and other apparatus
what important information are to be reviewed during pre-sampling preparation?
-maps, schedule, specific water quality parameters
- verify classification and water quality standards (DAO 34, DAO 35)
what are needed in establishing sampling locations?
-background information
- discharge water quality
- downstream impacts
a base/site map should depict:
-project
-sampling locations
-major water, land and road characteristics
equipment in sampling can include __, _______, _____, and _____
glass, plastic, ceramics, and metals
what gloves should be used?
disposable glove (powderless nitrile gloves)
Sampling information label
Parameters ___________________
Sample Site ___________________
Place ________________________
Source _______________________
Date of Sampling _______________
Time of Sampling ______________
Field condition _________________
Sampled by ___________________
No. of monthly samples for <5000 population
1
No. of monthly samples for 5000-100000 population
1 per 5000 population
No. of monthly samples for >100000
1 per 10,000 population, plus 10 additional samples
Equipment can include
glass, plastics, ceramics, and metals
gloves to use
powderless nitrile gloves
equipment for turbidity
turbidimeter
equipment for pH and temp
pH meter and thermometer
equipment for water sampling
rod and cup
rain measurement equipment
rain gauge
sample size and holding time for BOD
1000 mL ; 6 hrs
sample size and holding time for COD
100 mL ; 7 days
sample size and holding time for color
500 mL ; 48 hrs
sample size and holding time for oil and grease
1000 mL ; 28 days
preservation for BOD
Refrigerate, storage at 4 degree Celsius
preservation for COD
Analyze immediately; or
refrigerate and add
H2SO4 (sulfuric acid) to pH<2
preservation for color
Refrigerate, storage
at 4 degree Celsius
preservation for oil and grease
Add HCl or H2SO4 (sulfuric acid) to pH<2; refrigerate
significant wastewater parameters
pH
Color
Total suspended solids
Oil and grease
Turbidity
COD - chemical oxygen demand
BOD - biological oxygen demand
DO - dissolved oxygen
Temperature
what to consider when selecting sampling site?
-study objectives
- types of data needed
- equipment needs
- sampling methods
- historical information
-physical characteristics of area
- chemical and biological characteristics of the area (aquatic and terrestrial)
physical characteristics of area to be considered when selecting sampling site
-size and shape
-land use
- tributary and runoff characteristics
- geology
- point and nonpoint sources of contamination
- hydraulic conditions
-climate
- water depth
- fluvial-sediment transport characteristics
flowing water sites
- at or near stream-gauging stations
- straight reaches with uniform flow and uniform and stable bottom contour where constituents are well mixed along cross-section
- far enough above or below confluence of streamflow or point sources of contamination to avoid sampling cross section
- upstream reaches from bridges and other structures to avoid contamination
- unidirectional flow that does not include eddied
- at or near a transect reaches where data are collected and historical data are avilable
still-water sites
- use in-situ field measurement to determine vertical and spatial distribution of sampling locations
- avoid areas near structures such as harbor, boat ramps, piers, fuel docks, moored houses etc.
- select sites with historical data available, if possible
examples of still-water
lakes, ponds, reservoirs, marshes, swamps, backwaters
groundwater sample sites
-water supply wells
- observation wells
- monitoring wells
wells or piezometers for purpose of collecting hydrologic data
observation wells
installed specifically for assessment of physical, chemical, and biological characteristics of the aquifer
monitoring wells
