Water Quality & Management Midterm-2

Define “pollution”
The term “pollution” means man-made or man-induced (adverse) alteration of physical, Chemical, biological integrity of water.
– Pollution discussed, both from point and non- point sources, is understood to be caused by man’s cultural activates. This should be distinguished from water quality changes sometimes called “background pollution” from natural causes.
define “point-source”
The term “point source”, means any discernible confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.
–This term does not include agricultural stormwater discharges and return flows from irrigated agriculture.
Point sources enter the pollution transport route at discrete and identifiable locations.
• Usually can be directly measured or otherwise quantified and their impact directly evaluated.
-measured in load=lbs/ day (flow*concentration)
non-point source pollution
-very diffuse from a variety of sources, cant be traced to one point
• Non-point pollution control under 1987 clean Water Act (CWA).
Non-Point Source Pollution examples: brake dust, salts on the road, oils and gasoline on roads, pesticide application
-can control some during water collection
–Storm water pollution prevention plans necessary for construction industry
-can be easy to remove if floating, sludge blanket, can also settle out by gravity,
– can’t remove total dissolved solids
-One of the most important treatment philosophies
-Try to get microbes to do dirty work for us
-Physically remove by separation or settling
Total Solids (TS)- the residual remaining in the evaporation dish a[er drying at 104C for an hour.
• Depending on moisture content, a heat source can be utilized to evaporate the free water to prevent splattering (a loss in mass).
Total Dissolved Solids-everything that passes through filter paper
-is any fluid and material that passes through a 0.45 μm filter. In environmental samples this is called soluble matter
**Why 0.45um filter? Sands and silts are bigger than that
-Low TDS solutions have high resistance
–Most expensive contaminant to remove = TDS, from engineering and cost standpointCan use alum treatment, reverse osmosis, boiling
-TDS can also be referred to as conductivity
**ph:Total Dissolved Solids:
Any minerals, salts, metals, cations or anions dissolved in water
Everything but suspended solids (not dissolved) and the pure water
Total Suspended Solids-Undissolved solids, particulate matter and suspended solids (TSS) are any materials that are filtered by 0.45μm filter.
-anything left on filter paper

-TSS= Volatile Suspended Solids+ Fixed Suspended solids (Ss)
***TSS = VSS + FS

Total Solids(TS)=Total Suspended Solids(TSS) +Total Dissolved Solids (TDS)
Total Volatile Solids
Settable solids
-Use cones to see what comes out of solution in given time frame
Volatile solids
– mass lost during the hour at 550 degrees C
-VSS is the portion of total suspended solids that is voltilized at 550°C for one hour. Assumed to be organic ma^er related to biomass or sludge.
–TSS = (volatile suspended solids) VSS + Fixed SS
What percentage is volatile? Tells you what treatment to use
What percentage is volatile? Tells you what treatment to use
-If largely fixed, need a chemical process (ex. Iron)
-If volatile, good for biological processes
Organic compound
-An organic compound organic compound is a substance that is a substance that contains carbon.

-Cyanide, cyanates, carbon dioxide and its Cyanide, cyanates, carbon dioxide and its
relatives are exceptions relatives are exceptions

Importance of organic matter in water
-Organic material consumes oxygen in
-Organic material can cause taste and odor
problems in recreational and drinking problems
-Some material may be hazardous Some material may be hazardous
There are two important factors that can influence the amount of dissolved oxygen in water
-Water temperature (higher temp = lower saturated dissolved oxygen and lower temp=higher saturated DO)
-Organic matter
percent solids
Percent solids: they usually like to get it down to 4%
Biochemical Oxygen Demand is the estimation of the amount of oxygen required to stabilize biodegradable organics by a heterogeneous microbial population under aerobic conditions
– or BOD is the amount of oxygen used by organisms
during the breakdown of organic material
= A gross biological parameter
-BOD is considered an indirect measure of
the organic content of a sample
Activated sludge =
Activated sludge = sludge from wastewater treatment with bugs that are acclimated to digesting the material
BOD analysis
• Oxygen demand per unit time proportional to the amount of oxidizable remaining (usually 5 days)
• Slope of the curve is a function of the rate of oxidation
(First line on bottom in oxidation of carbon, over time →second line is oxidation of nitrogen)
• In bottle, two reactions are occurring:
– Oxidation of Carbon
– Oxidation of Nitrogen
• Microbes are performing two reactions:
– Synthesis (cell growth)
**- Endogenous respiration (cell death and metabolism)
The BOD5 is directly related to the amount of DO used up over the 5-day period day period
Chemical Oxygen Demand is the measure of oxygen equivalent of the organic fraction in the sample which is susceptible to potassium dichromate oxidation in an acid solution.
• Measures both biodegradable and non- biodegradable organics.
• KMnO4 or K2Cr2O7
-Will oxidize biological matter
-And non-biological organics
-Have to dispose of this material as a hazardous waste after using it
-Cant have chloride interference
-It’s a quick process, not as many interferences or complications
*COD is the equivalent amount of oxygen
needed to break down organic matter and
oxidize nitrogen compounds using strong
oxidizing agents
**Another means of measuring oxygen demand A
needed to oxidize organics and reduced nitrogenous compounds
–Faster than BOD
COD BOD ratios
If ratio of BOD/COD is near 1 than everything in that water is biological digestible
If at or near zero, nothing in that water is biologically digestible
^ Gives insight into how treatable that water is by a very efficient process
define effluent
A stream flowing out of a body of water. b. An outflow from a sewer or sewage system. c. A discharge of liquid waste, as from a factory or nuclear plant.
–sewage that has been treated in a septic tank or sewage treatment plant. 5. sewage or other liquid waste that is discharged into a body of wate
relating to, involving, or requiring free oxygen.
requires oxygen
COD testing
• Rapid test! – 3 hours total, 2 hours of reflux
• Add dichromate, sample, and dilute. Add sulfuric acid to catalyze straight chain organics, alcohols, and amino acids
• HgSO4 is added to complex chlorides and reduce chloride interference
• Reflux for 2 hours and measure amount of dichromate remaining.
• Amount depleted is the amount used for oxidation, and organics are translated into oxygen equivalents measured as COD.
COD advantages
• Quick process
• Not subject to as many interferences as BOD
• Can correlate results with BOD
• COD = COD0 + (BODult/0.9)
• Ra+o of BOD/COD
– What does it mean if BOD/COD = 0.1? – What does it mean if BOD/COD = 1.0?
COD disadvantiages
• Some aromatics not oxidized effectively by dichromate (BTEX, pyridine, ace+c acid)
• Chlorides may interfere, can add HgSO4. High chloride content can cause “false positive” or erroneously high results.
• Rate of oxidation not known
• Also measures inorganics (Fe2+, S2-, SO32-)
• Oxygen demand of ammonia is not known
• Hazardous waste! – the vials are
Total Organic Carbon is the measure of organic carbon per sample. May or may not be biodegradable.
• Measure ALL Carbon, including inorganic carbon and non-biodegradable.
• Probably the most useful for opera+ons monitoring because it may be automated
– is the amount of organic carbon bound in asample.
-total organic carbon = measure of all organic carbon in sample
-Can be useful, whether biodegradable or not you’re measuring in the sample with this method
-Can be expensive, quick
-Can be biologically digestable but unsure if it is since its such a wide parameter
-Fewer interferences than BOD and COD
• Interferences from nitrates, phosphates, and chlorides > 10,000 ppm/L.
• Can be expensive, as an instrument can be greater than $30,000.
Why is BOD, COD, and TOC important?
• For rou+ne plant control, BOD is not useful.
• Important to correlate BOD, COD, and TOC. – Portion of COD may be attributed to dichromate
oxida+on of ferrous iron, nitrogen sulfides, etc.
– BOD and COD might not include carbon compounds that a TOC analyzer can determine (such as some BTEX compounds).
– BOD suscep+ble to many variables for most organics.
– COD to TOC ra+o should approximate to the
stoichiometric ra+o of oxygen to carbon
• 32/12 = 2.66, though not always true
-Light and light defraction though given water column
-Could be solids, soil runoff,
Specifically refers to the passage or light through a column of water, or light scattering
May be caused by a variety of suspended materials that range from colloidal to coarse dispersion.
Total fixed solids is the portion that remains after heating. It is an approximation of the mineral matter a present
What contributes to turbidity?
soil disruption, runoff wastewater components industrial wastes, street washings microorganisms & algae
Impact of Turbidity:
Aesthetics: impacts consumption and usage of
drinking water
Filterability: as T increases, so does need and cost of
Disinfection: for some particulates, microbes
associate with the surface (pathogen load), and can interfere with disinfec+on processes
• The concentration of H+
• A measure of the intensity of acidic and alkaline condition of any aqueous solution
• Using the term “pH” expresses the H+ activity – related to concentration
PH measurement
Litmus paper
Samples can not be colored or highly turbid
Saturated Colomel electrode (less common)
Glass electrode: A closed end glass tube with a very thin glass membrane at +p with constant pH. An electric poten+al develops across the glass: a difference in [H+] ion. A special voltmeter detects this.
Terms Review
• Gram molecular weight or gram molar mass
• Molality = the number of moles of solute dissolved in one
kilogram of solvent
• Molarity = the number of moles of a solute dissolved in a liter of solution.
• Equivalent weight = molar mass/(H+ per mole)
• Equivalent = mass of compound / Equivalent weight
• Normality = (equivalents of X)/Liter
• Normality = Molarity x n
– (where n = the number of protons exchanged in a reaction).
Acids are substances that ionize in water to yield free protons or hydronium ions.
• Not all hydrogen is ionized in solution!!
Acids – disassociate to yield hydrogen ions (H+)
Acid – contributes hydrogen ions, H+
HCl =>H++Cl-
• Bases are substances that produce hydroxide ion in solution and accept protons.
Bases – disassociate to yield hydroxide (OH-)
Base – contributes hydroxyl ions, OH-
NaOH => Na+ + OH-
• Salts are the product of a an acid base reaction.
• Water is always a product in this reaction.
• Salts have a positive charge (cation) and a
negative charge (anion) group.
Amphoteric Substances
• These substances act as both base or acid. • These reac+ons are pH dependent.
• Examples include water and amino acids.
protonated and deprotonated acids
Protonated Acid (HA); deprotonated (A-)
Signficance of Ph
• Acid base neutralization
• Water Softening
• Precipitation reactions
• Coagulation
• Disinfection
• Corrosion control
• Biological processes for waste treatment
• Metals speciation
• Toxicity studies (e.g. NH3 is toxic to aqua+c life at high pH)
Disinfection Byproducts: Residual Chlorine

What are the health concerns?

If high: eye/nose/throat irritation, stomach discomfort, anemia
If low: increased risk of bacterial contamination
Disinfection Byproducts: Cryptospridium

What are the health concerns?

Watery diarrhea, cramps, vomiting; can become severe and chronic in people with immune deficiencies; can be fatal in debilitated people, the elderly, or infants
Disinfection Byproducts: Giardia

What are the health concerns?

Bloating, nausea, cramps, diarrhea, flatulence
Disinfection Byproducts: Lead

What are the health concerns?

Impaired physical or mental development; harm to attention span and learning abilities; kidney problems and high blood pressure
Disinfection Byproducts: Phenol

What are the health concerns?

Irritation of skin, eyes, and mucous membranes after short-term exposure at high levels
Definition of Eutrophication
(Process of aging lake)
• This natural aging process can effect all surface waters.
• It is the primary cause for the deterioration of natural bodies.
• Eutrophication requires various nutrients such as nitrogen, phosphorous, carbon, vitamin B12, etc.).
• Nutrients stimulate algal growth and macrophytes. This growth could significantly deteriorate water quality.
**It is a form of water pollution and like all other forms of pollution is the result of human activities influencing ecological cycles.
Red Tide
Red tide is a common name for a phenomenon known as an algal bloom (large concentrations of aquatic microorganisms) when it is caused by a few species of dinoflagellates and the bloom takes on a red or brown color.
-Some red tides are associated with the production of natural toxins, depletion of dissolved oxygen or other harmful effects, and are generally described as harmful algal blooms.
–Red tide – the bacteria releases these toxins and cause acute respiratory affects- you dont even have to be drinking the water and it can be exposed. Can be indirect or direct exposure
Factors affecting Eutrophication: natural and man-made
Natural- solar radiation, temperature, morphology, nutrients, and specific organisms.
• Cultural (Man Made) factors are wastewater discharges, non-point source runoff, and urban runoff (increased urbanization).
• Approaches to mitigate eutrophication are nutrient immobilization/removal, land-use planning and control of point/non-points sources.
–Depending on where are you you may or not have algae blooms – you need natural and human conditions that affect this phenomemon (algae bloom)
Two limiting nutrients for eutrophication
1. nitrogen
2. phosphorous (fresh water)
–level of nutrients up to 2 mg/L for both nitrogen and phosphorous above which can inhibit algal growth.
– – thelevels of these two nutrients determine the biological productivity of the lake, pond, or

–Eutrophication happens when phophorus and nitrogen exceed the ability for the phytoplankyton to assimiliate it

Nutrient Levels for enhancing eutrophication
• Level of nutrients up to 2 mg/L for both nitrogen and phosphorous above which can inhibit algal growth.
• Algal blooms are related to the density of plankton. If the number of plankton is greater than 0.5 to 1.0 x 106 plankton per liter), then you have a algal bloom.
• As a result, the criteria for nutrient concentrations causing algal blooms varies from system to system.
It is defined as the rate of organic carbon fixation by photosynthesis. By definition, the gross primary productivity is the quantity of carbon taken-up into organic reservoir. The net primary productivity can be obtained by subtracting the carbon loss by respiration (defined as the measurement of eutrophication).
Measurement of eutrophication
• Pnet = Pgross – Respiration = Eutrophication

• Measurement of Productivity
H2O + CO2 + sunlight–>O2 + CH2 + Energy
*Needs Chlorophyll and Enzymes produces one mole of oxygen and biomass

Nutrients and Water Quality
• Leading Cause of Impairment in Lakes
• Second Leading Cause of Impairment of Rivers and Streams
• Nutrients Contributed 25 -50% of Impairment Nationally
***euthropication is the leading cause of impairment in lakes – and is second for rivers and streams ( 1st is point source) and most of these are caused by the limiting factors of nitrogen and phosophorus
Nutrients in Water
• EssentialforHealth
• DiversityofSurface Water
Four abiotic cycles
Water cycle
Carbon cycle
Nitrogen cycle
Phosphorus cycle
Alkalinity- 1. ability to neutralize a acid
2. Inorangic CO2 concentration of a given water body
Norganic chemistry of water
-water can be a nautral CO2 sink
How does water quality affect the carbon cycle?
Main issues with water pollution and eutrophication
organic wastes
chemical pollutants
In past ~ 40 yrs, reduction in:
• ____
• ______
• _____
• _____
In past ~ 40 yrs, reduction in:
• Toxic discharges
• point sources of Phosphorus Still largely uncontrolled:
• Sewage inputs of Nitrogen
• non-point source N & P
Eutrophication one definition
Process in which nutrient runoff from agricultural lands or
livestock operations causes photosynthetic organisms in ponds and lakes to multiply rapidly (one definition)
–Eutrophication = nutrient over enrichment Phosphorus freshwater Nitrogen salt & brackish
–Limiting nutrient: The one in shortest supply relative to demand. If you add more of that nutrient the plants/algae will grow
Consequences of Eutrophication
Dead zones
Harmful algal blooms
Coral death
Effects of Eutrophication
-The species diversity decreases
-Plant and animal biomass increase
-Turbidity increases because of increased particles suspended within water
-Rate of sedimentation increases, shortening the lifespan of the lake
-anoxic conditions may develop
-reduction in length of food chains
-Loss of species diversities
When you have stratifcation – the oxygen goes stagnant
-wind causes a lot of mixing
-summer: heating faster than mixing warm water is less dense and floats to top requiring a lot of wind to mix
You have mixing within the top and bottom zones but not inbetween zones
Strafication is less likely- the marker between zones is the “thermocline”
Gulf Coast dead zone
Anoxic section
-Fish and large animals swim away from poor water, small things die
Different temperature water =
different water density
Salt water is denser
Define epilimnion, metalimnion, hypolimnion,
-epilimnion-warm surface waters
-mealimnion-zone of rapid temperature chance or thermocline
-hypolimnion: cooler deep waters
eutrophication explained
1. fertilizer is spread on land
2. fertizlier washed by rain and down in to solil and the fertilzer is transported to lake by underground water
3. the presence of fertilizer rich in nitrogren and phosphates in lakes causes overgrowth of the algae and aquatic plants.
4. Now no sunlight can reach the bottom of the light causing the algae and plants to die.
5. The bacteria then comes in to decompose the algae. WHen doing this bacteria uses up all the oxygen in the lake making it anoxic.
6. This causes all the living organisms to die.
Primary production and nutrient cycling:
-Phytoplankton (free-floating algae) contribute most of the net production, and are the base of the food web, are confined to surface waters due to light limitation and density stratification.
-NPP-Net Primary Production- in epilimnion depends on nutrient delivery to epilimnion and regeneration
-low levels of nutrients are found in surface waters due to efficient phytoplankon uptake
Harmful algal blooms in Oceans: Pfiesteria
Coast of Carolinas
Floating microorganisms that thrives in nutrient conditions Highly toxic to fish and humans
coral reef overgrowth
Nutrients stimulate algae that cover coral
Lose habitat and biodiversity Lose economic benefits
Nutrients of Environmental Concerns
• Nitrogen for Marine Environment
• Phosphorus for Fresh Water Systems
• Nitrates
Blue Baby Disease
• Nitrites
Possible Carcinogens
• Ecological
Eutrophication of Estuaries and Coastal Waters Harmful Algal Bloom
Brown/Red Tides
Approaches for controlling nitrogen in the Mississippi River Basin:
-on-site control of agriculture drainage

-off-site control of agricultureal drainage

On-Site control of agricultural drainage:
-Changing cropping systems
-Reducing nitrogen fertilizer application rates
-Managing manure spreading
-Managing the timing of nitrogen application
-Using nitrification inhibitors
-Changing tillage methods
-Increasing drainage tile spacing
Off-site control of agricultural drainage:
-Riparian zones
Approaches for controlling nitrogen in the Mississippi River Basin:Urban and suburban:
nonpoint source control
Point source control
-Urban and suburban nonpoint source control
-Point source control:
• Environmentaltechnology • Ecotechnology
Gulf of Mexico
• Nitrogen from Agriculture
• Contributed by the Main Stem of Mississippi River
• In Stream Denitrification
Phosphates in Water:
-ecological concerns
• No Direct Human Toxic Effects
• High Reactivity with Soil Components
• Immobile in Soils
– No Concern about Ground Water Pollution
• Ecological Concerns
– Algal blooms in Great Lakes
• High Phosphate Detergents
• Point Sources of Pollution
Effects of Excessive Phosphates
• Hyper-eutrophication
• Low Dissolved Oxygen
• Fish Kill
• Increased Sediment Accumulation • Species Shift
• Pfiesteria
National Strategy for Nutrient Criteria
• Not to Develop a Single Value for N and P
• Base Criteria on:
– Ecological Regions
– Types of Waters (Lakes, Rivers, Wetlands and Coastal waters)
– Use Reference (Pristine) conditions for Setting Reference Levels
Lake Classification:
-post eutrophic
• Oligotrophic lakes are nutrient poor with low productivity (Oligo meaning few).
• Mesotrophic lakes are moderate levels of nutrients (Meso meaning moderate).
• Eutrophic lakes are highly productive (Eutro meaning well nourished).
• Post eutrophic or hypertophic lake are lakes being transformed into marshes.
Trophic states:
• Autotrophic lake is a lake receiving a major portion of its nutrients from internal sources or the lake itself (sediments and atmosphere).
• Allotrophic lake is a lake receiving a major potrion of its nutrients from external sources or outside the lake (runoff into the lake).
Biological Indicators To Monitor Water Quality of Streams & Lakes:
Trent Biotic Index

and limitations

• Rankings are made according to presence/absence of certain micro invertebrate:
1) Plecoptera nymphs
2) Ephemeroptera nymphs
3) Thichoptera larvae
4) Gammarus
5) Asellus
6) Tubificids and or Chironomid larvae
• Insensitive to certain habitats
• Gives erroneous results
Biological Indicators To Monitor Water Quality of Streams & Lakes:

Ecological Community methods

and limitations

-Diversity–considers #s and -Distribution Species #/Richness–a simple species count Biomass–one species to another
-Advanced Statistics –showing different relationships (component analysis,linear regression,etc.)

-Long time to identify each organism
-Need Background in Taxonomy of individual species
-Large sample size & familiar with advanced statistics

Eutrophication Restoration:
On-site restoration techniques
-point source controls
-nonpoint source controls
-Manure management
-Riparian buffer strips
-Storm water drain management –
-Construction site soil erosion management
Overiview of water stratification:
-Seasonal changes in temperature, combined with
the properties of water, cause changes in lake water column structure.
-Physical changes in water column structure (e.g. stratification) have profound effects on carbon and nutrient cycling, and impact biological communities and whole lake ecosystems
cultural eutrophication
• Eutrophication is a natural process, but human impact has greatly accelerated this process (Cultural Eutrophication).
ecotoxicology definition
• Ecotoxicology is concerned with the toxic effects of chemical and physical agents on living organisms, especially on populations and communities within defined ecosystems;
• Includes the transfer pathway of those agents and their interactions with the environment.
Ecotoxicology is the study of ____
pollutants in an ecosystem
• Effects on ecosystem
• Indirect effects, slow – (may be over generations)
• Multi-discipline
• Silent Spring, 1962 – Pesticides in env. – Effect on wildlife – Egg shell thinning
Ecotoxicology involves ___
and what is its importance
• Involves:
– Pathways, persistence, bioavailability, bioaccumulation (plants/ animals), biomagnification (food chain)
– Fate of contaminants and potential impacts
– 63,000 chemicals,
• Importance:
– Impact assessment
– Risk assessment
– Risk management
– Environmental policy
• Effects – don’t know how to measure or monitor for effects
Risk Management of Environmental Chemicals-For the risk assessment of an environmental chemical, the four step process developed by the U.S. Government can be applied
1. hazard identification -“is the chemical toxic?”
2. Dose response assessment – ” how toxic is the chemical?”
3. exposure assessment-“who is exposed to the chemical, how often and how long?”
4. Risk Characterization- “so what? what are the consequences? Do we have a problem?”
***After risk characterization, the acceptable level of exposure via food, water, ambient air, etc. is determined. Alternatives to control the risk are then studied and managers decide how to reduce the risk to acceptable level and execute all necessary action.
Aims of this 4 step approach to environmental risk managemnet should:
Aims of this approach should:
1. Further elucidate the vital signs of ecosystem health,
2. Diagnose early warning symptoms of ecosystem stress,
3. Assess the sensi+vity and long-term response of ecosystems to low doses of contaminants; and,
4. Formulate proper treatment protocols for ecosystem rehabilitation,
– Links aquatic toxicology and environmental chemistry,
– Provides background for aquatic hazard assessment and environmental fate modeling
– Contaminant – Substance released by man’s activities.
– Pollutant – all substances that occur in the environment and which have a deleterious effect on living organisms.
– Toxicant – agent or material capable of producing an adverse response or effect in a biological system, seriously injuring structure or function or producing death.
– Xenobiotic – new – made chemicals, not produced in Nature.
BIotope- A physical and chemical environment-biotope
Biocenose- A community of living beings – biocenose
-The basis for determining the effects of contaminants on ecosystem is at ________ level
-At___ level, response can be:
–acute toxicity causing:
–at population level:
–at community level:
-change in ecosystem
-The basis for determining the effects of contaminants
on ecosystem is at organism level
-At organism level, response can be:
-00-Acute toxicity causing mortality
– Chronically accumulating damage ultimately causing death
– Sublethal impairment of various aspects of physiology and morphology
– Sublethal behavioral effects
– Measurable biochemical changes
-00- At population level, response can be:
– Size and dynamics (based on birth rates, death rates, gains, from immigration and losses from emigration)
– Cause a reduction or an increase in the natural flow chart of numbers, in the biomass, sex ratio, etc.
–00–At community level, response can be: – Species diversity
– Predator prey relationship, etc
–000-Change in ecosystem
– Nutrient cycling rates, patterns of nutrient flow,
– Physical-chemical conditions etc.
Distribution factors:
Physiochemical Characteristics of biotopes:
– Current speed and stability of water depth
– Light and temperature regimes
– Substratum conditions
– D.O. and water quality
– Integration of all these factors gives rise to zonation phenomena
BIoligcal interactions with pollutants
-Toxic: Causing a deleterious response in a biologic system, seriously injuring function, or producing death. These effects may result from acute conditions (short high-dose exposure), chronic (long-term, low-dose) exposure, or subchronic (intermediate term and dose) exposure.
-Neurotoxic: Exerting a destructive or poisonous effect on nerve tissue.
-Carcinogenic: Causing or inducing uncontrolled growth of aberrant cells into malignant tumors.
-Mutagenic: Causing heritable alteration of the genetic material within living cells.
-Teratogenic: Causing nonhereditary congenital malformations (birth defects) in offspring.
• LC50
• LD50
• LC50 – Lethal concentration which results in 50% death of the test population over a specified +me period (usually 96 hours for fish).
• LD50 – lethal dose (usually given as a single dose to mammals) which results in 50% death of the test population.
• EC50
• IC50
• EC50 – Effective concentration which results in a designated response to 50% of the test population. An effect to any percent of the population could also be employed, i.e., EC10.
• IC50 – Inhibitory concentration = toxic conc. Causing a given % decrease in non-quantal biological measurement (growth or fecundity)
-LOAEL: lowest observed adverse effect level
-NOAEL- No observed adverse effect level during life cycle
-MATC-maximum acceptable toxic concentration ( same as noael)
-NOEL-NO observed effect level
NOEL = highest effluent concentration at which no unacceptable effect will occur, even at continuous exposure
Elements of Toxicity Testing
• The four major elements of a toxicity test for a whole effluent include:
– Obtaining a representative effluent or water sample(s)
– Procuring or culturing a healthy test organism
– Applying the proper experimental design
– Calculating the endpoint
Water Quality Based Toxics Control
1. New EPA Policy for the development of water quality based permit limitations for toxic pollutants
2. Regulation of toxics difficult
a. Great number of toxics that can be discharged
b. Difficulty in analysis
c. Synergistic effects of chemical mixtures
3. Whole effluent approach
a. Measure toxicity of discharges
b. Effluent sample collected and tested with organisms
Water Quality Based Toxics Control
Whole effluent Approach Procedure:
1. Dilute effluent with 100%,.30%, 10%, 1%, control
a. Use receiving water for diluent
b. Place organisms in test chambers for given time periods
c. At given time periods, count organisms for endpoints
(1) Mortality
(2) Lower fecundity
(3) Reduced growth rates
d. Endpoints (1) – (3) can be used to quantify concentration that would cause in stream impact if exceeded for a particular time
e. Stated as an LC50 or No Observed Effect Level (NOEL)
(1) NOEL = highest effluent concentration at which no unacceptable effect will occur, even at continuous exposure
Application to permits -toxicity
Application to Permits
a. Permit limits can be expressed as LC5O or NOEL’S
b. Use of Toxicity Units (TU’s)
–Toxicity Unit
a. 100 divided by toxicity measured b. TU = ____100_____
c. LC5O, NOEL expressed as percent effluent in receiving water
d. An effluent with a toxicity of 10% is an effluent containing 10 TU’s
e. Two measures
(1) TUa – – Acute toxicity units (2) TUc – – Chronic toxicity units
WHOle effluent advantages and disadvantages
Whole Effluent Approach Advantages
a. Aggregate toxicity of all cons+tuents measured
b. Toxic effect(s) limited by limi+ng one parameter, TU c. Bioavailability of toxics assessed
d. Effects of interac+ons measured
Whole Effluent Approach Disadvantages
a. Effluent toxicity treatability data lacking
b. Where chemical/physical changes act in such a way to “release” downstream, not measured
c. Proper+es of specific chemicals in complex effluents not assessed
(1) Bioaccumula+on (2) Carcinogenicity
• Need to know what toxic effects are on streams by compounds and why industry is now required to do bioassays.
• No two organisms act the same to the same compound or con’t of compound. This is dealt with in a Probability Analysis and Frequency Distribu+on:
Ecotoxiccology: overview main points
• Ecotoxicology provides the scientific basis for environmental protection policy
– Determine fate/behavior of contaminants – Risk assessment/management
– Water quality standard seung
• Emerging science, holistic, multidiscipline approach needed to:
– Further elucidate the vital signs of ecosystem health
– Diagnose early warning symptoms of ecosystem stress
– Assess the sensitivity and long term response of ecosystems to low doses of contaminants; and,
– Formulate proper treatment protocols for ecosystem rehabilitation.
Major sources of potable water
-groundwater -get it by drill
-lakes and impoundments
Amount of freshwater is dependent on what two things
1. temperature
2. population density
Ions to be expected in water
Your going to have cations and anions positively ad negatively charged always in water
-Cations: Calcium, Magnesium, Sodium, potassium, iron
-Anions: Bicarbonate (alkalkinity), Sulfate, Chloride (TDS), Nitrate
What are responsible for hardness
Calcium and sodium -both cations
Ground waters will generally have (lower/higher) levels of hardwater and dissolve solids than surface water
and why?
Ground waters will generally have higher levels of hardwater and dissolve solids than surface water

-ground water dissolves Limestone increasing hard water (minerals)

General characteristics of Groundwater
1. laminar flow (linear flow) -slow recovery from contamination
2. constant composition
3. may contain gases such as CO2, H2s, Ch4, Rn222
4. May contain excessive concentrations of elements such as iron, magnesium, calcium, magnesium fluoride, selenium, arsenic, radium, sodium, nitrates.
5. low in numbers of microorganisms
6. subject to contamination from infiltration and subsequent percolation
**can have some percolation from rain water that can contimate
**surface waters u have to filter prior to distribution
General characteristics of surface water
1. turbulence and mixing aiding dilution of contaminants
2. rapid recovery from contamination
3. since water is the universal solvent may find almost anything
4. Since gases are in equilibrium with atmosphere, low concentrations of CO2, etc
5. subject to wastewater discharges and nonpoint source pollution thus may be low in dissolved oxygen
6. may have high concentrations of microorganisms
***surface waters are typically lower in hardness than groundwater
— surface water usually has a lot of waste water discharge
General Characteristics of impounded waters
-seasonal variation in quality because of density stratification
-quality of surface waters may be significantly different than that found at lower levels because of stratifcation
-when the impoundment stratifies, if there are organics in lower levels the oxygen levels may be reduced to near zero by bacterial action and because of the lack of oxygen transfer from the upper layers of the impoundment this oxygen may not be replaced.
Seawater major consituents
sodium- 10,500 mg
chloride- 1,900
What are the three areas of water use and who uses the mose pure water and which uses the most volume
1. domestic
2. agriculure
3. industry-
Purest water – industrial has the largest volume of water due to the need for electricity (water and electricity are intertwined)- cooling towers and broilers require an immense amount of water -exhausted heat is cooled in cooling tower— and also requires the purest form of water becuase if it loaded with TDS it will scale out those pipes and prevent heat transfer
Major uses of Domestic Water supply: Sources
-Rain (particulates or acid rain)
-Spring or well waters- dependent on weather
-lakes or streams- surface water
-Desalinization- sea bracking brine water-high ost
-Reclamation of wastewater- something coming on line- take wastewater and reinject into groundwater to directly recharge
Methods to take out salt
Desalinization and Reverse Osmosis Membranes-

-semipermeable membrane — apply pressue to squeeze water through membrane and are left with a brine reject ( high concentration of brine)- have to go through filtration steps first

why do you need high quality water for boilers
HIgh quality water is needed for boilers – because if you have hard salts or alkalinity that causes scale then it will interfere with the processes or cause blow ups