Miller Chapter 19Miller Chapter 19

Water PollutionWater Pollution

Pollution DefinedPollution Defined Any chemical , biological, or Any chemical , biological, or

physical change in water quality physical change in water quality that has a harmful effect on that has a harmful effect on living organisms or makes water living organisms or makes water unsuitable for desired uses.unsuitable for desired uses.

Types and Sources of Water Types and Sources of Water PollutionPollution

Infectious AgentsInfectious Agents Oxygen-Oxygen-

DemandingDemanding Inorganic Inorganic

ChemicalsChemicals Organic ChemicalsOrganic Chemicals Plant NutrientsPlant Nutrients SedimentSediment Radioactive Radioactive ThermalThermal

CATAGORIES OF POLLUTANTS

I. Methods of Determining I. Methods of Determining Water QualityWater Quality

A. Coliform BacteriaA. Coliform Bacteria 0 colonies per 100ml for drinking water0 colonies per 100ml for drinking water 200 colonies per 100ml for swimming200 colonies per 100ml for swimming

B. Biological Oxygen Demand B. Biological Oxygen Demand (BOD)(BOD)

The amount of oxygen needed by The amount of oxygen needed by decomposers to break down organic decomposers to break down organic

material over a 5-day period at 68material over a 5-day period at 680FF

Dissolved Oxygen (DO)Dissolved Oxygen (DO) Only a few species of fish can

survive when the D.O. level drops below 4 ppmWaterWater

QualityQuality

GoodGood 8-98-9

Do (ppm) at 20˚CDo (ppm) at 20˚C

SlightlySlightlypollutedpolluted

ModeratelyModeratelypollutedpollutedHeavilyHeavily

pollutedpollutedGravelyGravelypollutedpolluted

6.7-86.7-8

4.5-6.74.5-6.7

Below 4.5Below 4.5

Below 4Below 4

C. Chemical C. Chemical AnalysisAnalysis

Determine Determine the levels the levels of organic of organic and and inorganic inorganic pollutionpollution

D. Indicator SpeciesD. Indicator Species Indicator species Indicator species

can be used to can be used to monitor water monitor water qualityquality

Ex: Mussels, Ex: Mussels, Cattails, Insect Cattails, Insect larvalarva

Analyzed to Analyzed to measure the levels measure the levels of various chemicalsof various chemicals

II. Sources of PollutionII. Sources of PollutionA. Point SourcesA. Point Sources

-Discharge from a specific -Discharge from a specific location (pipe, ditch or sewer) location (pipe, ditch or sewer)

-Easier to identify and regulate-Easier to identify and regulate

Ex: Factories, Sewage Ex: Factories, Sewage Treatment Plants, Mines, Treatment Plants, Mines, Thermal Outlets and Oil Thermal Outlets and Oil Tankers.Tankers.

B. Non-Point SourcesB. Non-Point Sources

-Cannot be traced to a specific -Cannot be traced to a specific discharge discharge

-Difficult to identify and control-Difficult to identify and control

Ex: Golf Courses, Agriculture, Ex: Golf Courses, Agriculture, HomesHomes

III.Water PollutionIII.Water PollutionA. A. Rivers and StreamsRivers and Streams:: -Most pollution in the form of: chemicals from industry or

mines, malfunctioning sewage

plants, Non-point runoff Naturally, streams and

rivers can rebound: As long they are not

overloaded with pollutants & Flow is not reduced

-The breakdown of degradable -The breakdown of degradable wastes by bacteria depletes wastes by bacteria depletes dissolved oxygen dissolved oxygen

-Reduces the population of -Reduces the population of oxygen requiring organisms.oxygen requiring organisms.

-Shown as an -Shown as an OXYGEN SAG OXYGEN SAG CURVECURVE

Clean Zone DecompositionZone

Septic Zone Recovery Zone Clean Zone

(Trout, perch, bass,mayfly, stonefly)

(carp, gar,Leeches)

Fish absent, fungi,Sludge worms,

bacteria(anaerobic)

Normal clean water organisms

8 ppm

Dissolved oxygen

Biological oxygendemand

Oxygen sag

2 ppm

8 ppm

Co

nce

ntr

atio

nT

ypes

of

org

anis

ms

Time of distance downstream

Direction of flow

Point of waste orheat discharge

Trash fish

-Recovery from oxygen depletion is based on the volume of the pollutant and …

Stream Volume Flow Rate Temperature pH level

Stream and River Success Stories:Stream and River Success Stories:

-Water Pollution Control Laws of the 1970’s:

Downstream withdraw of drinking water

Reduce point-source pollution Increase # of treatment plants

-Ohio’s Cuyahoga River (caught on fire in 1959 and 1969)

Now used for boating and fishing

CLEAN WATER ACT and NON-POINT POLLUTION

Stream PollutionStream Pollution: The Bad News: The Bad News Accidental release of organic and Accidental release of organic and

inorganic chemicalsinorganic chemicals Malfunctioning sewage treatment Malfunctioning sewage treatment

plantsplants Non-point run-off of pesticidesNon-point run-off of pesticidesWORLD WIDEWORLD WIDE:: 2/3 of streams monitored in 2/3 of streams monitored in ChinaChina

and and IndiaIndia are severely polluted are severely polluted

B. B. LakesLakes-More vulnerable than streams

due to… Stratified layers, Little flow, Low water volumes. Vulnerable to Biological Biological

MagnificationMagnification & & Cultural EutrificationCultural Eutrification:: Human activities that increase

the level of plant nutrients in lakes

Rainbow smelt1.04 ppm

Zooplankton0.123 ppm

Phytoplankton0.0025 ppm

Water0.000002 ppm

Herring gull124 ppm

Lake trout4.83 ppm

Herring gull eggs124 ppm

The Terrible TwelveThe Terrible Twelve

Biological Magnification

Cultural EutrophicationCultural EutrophicationDischarge of untreated

municipal sewage(nitrates and phosphates)

Nitrogen compoundsproduced by cars

and factories

Discharge of treatedmunicipal sewage

(primary and secondarytreatment:

nitrates and phosphates)

Discharge of detergents

( phosphates)

Natural runoff(nitrates andphosphates

Manure runoffFrom feedlots(nitrates andPhosphates,

ammonia)

Dissolving of nitrogen oxides

(from internal combustionengines and furnaces)

Runoff and erosion(from from cultivation,mining, construction,

and poor land use)

Runoff from streets,lawns, and construction

lots (nitrates andphosphates)

Lake ecosystemnutrient overload

and breakdown of chemical cycling

GREAT LAKESGREAT LAKESREAD PAGES 483-484READ PAGES 483-484

C. C. GroundwaterGroundwater

- Easily contaminated by - Easily contaminated by everyday activitieseveryday activities

- Flows slowly so it cannot - Flows slowly so it cannot dilute/disperse dilute/disperse contaminantscontaminants

- Small population of - Small population of decomposersdecomposers

- Cold temps. Slow Rx that - Cold temps. Slow Rx that remove wastesremove wastes

10 to 20 percent

Greater than 20 percent

Not tested

Contaminated Probability

Extent of Contamination:Extent of Contamination:

- Up to 25% of usable, U.S. - Up to 25% of usable, U.S. groundwatergroundwater

- 60% of liquid waste injected - 60% of liquid waste injected into deep underground wellsinto deep underground wells

- Pumping of water at - Pumping of water at coastlines causes coastlines causes contamination of drinking contamination of drinking water by saltwater intrusion.water by saltwater intrusion.

Waste lagoon,pond, or basin

Miningsite

Pumpingwell

Waterpumping

well

Sewer

Cesspool,septictank

Hazardous wasteinjectionwell

Buried gasolineand solvent

tanksLandfill

Roadsalt

Unconfined freshwater aquifer

Confined freshwater aquifer

Confined aquifer Discharge

Leakagefrom faultycasingGroundwater

Groundwater flow

IV. Preventing/Reducing IV. Preventing/Reducing Water PollutionWater Pollution

1.1. PreventionPrevention::

-Wiser use of fertilizer and pesticides

-Plant buffer zones to control runoff

-Banning Deep Injection Wells

-Monitoring of waterways and aquifers

-Clean Water Act (1977)

-Water Quality Act (1987)

Householdwastewater

Perforatedpipe

Distributionbox

(optional)

Septic tank

Manhole (forcleanout)

Drainfield

Vent pipe

Nonperforatedpipe

Gravel orcrushedstone

2. Reduction:2. Reduction:- Septic Systems- Septic Systems

--Sewage TreatmentSewage Treatment

3 Levels of Purification

A. Primary –

mechanical treatment

B. Secondary –

biological treatment

C. Advanced –

Specialized chemical and physical processes to remove specific contaminants

Raw sewagefrom sewers

Bar screenGritchamber Settling tank Aeration tankSettling tank

Chlorinedisinfection tank

Sludge

Sludge digester

Activated sludge

Air pump

(kills bacteria)

To river, lake,or ocean

Sludge drying bed

Disposed of in landfill orocean or applied to cropland,pasture, or rangeland

Primary Secondary

Fig. 19.15, p. 494

Effluent fromSecondarytreatment

Alumflocculation

plus sedimentsActivated

carbon

Desalination(electrodialysis

or reverse osmosis)Nitrate

removal

Specializedcompound

removal(DDT, etc.)

98% ofsuspended solids

90% ofphosphates

98% ofdissolvedorganics

Most ofdissolved salts

Recycled to landfor irrigation

and fertilization

To rivers, lakes,streams, oceans,

reservoirs, or industries

What about the Sludge?What about the Sludge? Sewage sludge is a highly toxic Sewage sludge is a highly toxic

mix of chemicals, infectious mix of chemicals, infectious agents, and settle solids.agents, and settle solids.

-9% converted to compost-9% converted to compost -36% applied as fertilizer-36% applied as fertilizer -55% dumped in landfills or -55% dumped in landfills or burnedburned

(1) Raw sewage drains by gravity into the first pool and flows through a long perforated PVC pipe into a bed of limestone gravel.

(3) Wastewater flows through another perforated pipe into a second pool, where the same process is repeated.

(2) Microbes in the limestone gravel break down the sewage into chemicals, that can be absorbed by the plant roots, and the gravel absorbs phosphorus.

(4) Treated water flowing from the second pool is nearly free of bacteria and plant nutrients. Treated water can be recycled for irrigation and flushing toilets.

45 centimeterlayer of limestonegravel coated with

decomposing bacteriaFirst concrete pool Second concrete pool

Sewage

Wetland typeplants

Wetland typeplants

Treatedwater

-Wastewater Gardens-Wastewater Gardens

-Double Vault Systems and Dry Toilets-Double Vault Systems and Dry Toilets

V. Drinking Water QualityV. Drinking Water QualityV. Drinking Water QualityV. Drinking Water Quality-In U.S. we have safe drinking water standards set by the Safe Drinking Water Act of 1974

-Establishes Maximum Maximum Contamination LevelsContamination Levels for any pollutants.

-Effects “city” water only, not wells.

-Purification of water done in various ways

-1/3 of all bottled -1/3 of all bottled water is water is contaminated with contaminated with bacteriabacteria

-International Bottled -International Bottled Water Association Water Association sets/maintains sets/maintains standards for standards for bottled water.bottled water.