Chapter 19 Water Pollution - Shirleytempledolls



Chapter 19 Water Pollution

Learning Nature’s Ways to Purify sewage

Arcata California – took land that was once a dump and converted it into a marsh – where the water acts as an inexpensive waste water treatment plant. Sewage first into settling ponds – then to marsh where bacteria and aquatic plants filter out other things – hope to send it to a salmon hatchery and make $

19-1 Types and Sources of Water Pollution ( learn table 19-1)

Definition – Any chemical, biological or physical change in water quality that has a harmful effect or makes water unfit for desired uses.

Classes of Pollutants

Disease causing agents

pathogens (bacteria, viruses, protozoans, and parasitic worms ) diseases table 20-1

causes 80% of deaths in developing countries

good indicator is number of coliform bacteria

drinking water should be 0 colonies to 100ml

swimming should be 200 colonies/100ml

humans excrete 2 billion each day

Oxygen demanding wastes

organic wastes that bacteria feed on - need large amounts of oxygen

measured by BOD – biological oxygen demand – where we measure the amount of dissolved oxygen needed by aerobic decomposers to break down organic material over a 5 day period in a certain volume of water at a certain temp (20o C)

Water Soluble Inorganic Chemicals

acids, salts, mercury, lead etc.

Selenium – comes from irrigation run off and has caused the death of most fish and birds in Calif – Keterson wildlife refuge – authorities refused to recognize and demoted several until printed in Sports Illustrated.

Inorganic Plant Nutrients

nitrates and phosphates

cause excessive growth of algae thus toxins and when they die use up Oxygen from other organisms

lowers oxygen carrying capacity of blood – killing unborn and infants

Organic Chemicals

oil, gas plastics, pesticides, cleaning solvents, detergents

nervous system damage, reproductive disorders, cancers

Sediment or Organic matter

soil from erosion

reduces photosynthesis and fouls gills, clouds water, irritates gills of fish, carry pesticides,

Radioactive materials – (nuclear)

iodine, radon, uranium, cesium

genetic mutations, birth defects, cancers, miscarriages,

Heat

absorbed by water used to cool industrial power plants

Genetic pollution

caused by non native species

Detection of pollution

Chemical Analysis

Indicator species

Computer models

Sources of Water Pollution

Point sources

ditches, pipes of sewers – very specific

Nonpoint sources

souces that cannot be traced

usually runoff from large areas of land or airshed

33%-64% of water pollution from non point

difficult to control

19-2 + 3 Pollution of Streams and Lakes

Pollution problems of streams

Normally streams recover rapidly from pollution because they are moving and use dilution and bacterial decay

Don’t work well if dammed up or overloaded

Oxygen Sag curves – show have well a stream handles pollution

Progress made in reducing stream pollution

require cities to pull drinking water downstream instead of upstream would help tremendously

Water cleanup laws enacted in 1970’s have increased number of waste water treatment plants – and decreased the pollution of disease causing and oxygen demand organisms

Case study – Cuyahoga River in Ohio – once caught fire in 1959 and 1969 due to pollution. Today river used by boaters and anglers.

Great Britain has also cleaned up the Thames river

Bad News

Large fish kills and contamination still occurs – by industry, sewage treatment plants and by non-point runoff of pesticides from cropland.

Ex. Sandoz chemical plant in Switzerland caught fire and dumped chemicals into the Rhine river – killed life from Switzerland – Netherlands

Becoming more of a problem in developing countries

Pollution in Lakes

Stratification can intensify pollution problems

Because water is not moving and going somewhere dilution does not help much – in fact can be concentrated.

Biological magnification also a problem

Cultural Eutrophication – run off from surrounding lands increase plant nutrients and cause eutrophication plants take over and block out the light – then die and fall to the bottom as they are rotting they take up the oxygen asphyxiating other organisms

Prevention

advanced waste treatment

ban or limit phosphates in detergents

soil conservation and land use control

Cures

dredge bottom sediments to remove nutrients

remove excess weeds

pump air through the lakes

Case Study – Great Lakes

Contain 95% of surface freshwater in USA

Even though it is big – very susceptible to pollution – because only 1% of the water leaves thru the St. Lawerence

By 1960 suffering cultural eutrophication and genetic pollution – worst was Lake Erie because shallow

Since 1972 clean up has occurred and Great Lakes have less levels of phosphates, decreased levels of coliform bacteria, DDT

In 1991 US feels that the great lakes is an environmental Hot spot ( one of 27 and should be cleaned up), No $ provided

In spite of industry opposition Environmentalist urge ban

use of Cl in pulp and paper industries

all new incenerators in the area

discharge into the lakes 70 toxic chemicals

Concern – levels still rising

Toxic chemicals carried by air currents from TX and CA.

PCB built up in food chains

Zebra Mussel

In 1986 brought to Detroit by ship emptying bilge – no predator

Out compete native species, clog irrigation pipes, grow on ships, foul beaches – have spread to most of US

Damage has cost $10 billion

Good news for number of aquatic plants – because consumes algae, making water clearer, so plants increase photosynthesis

Quagga Mussel

In 1991 came from Russia

May be worse than Zebra mussel because can tolerate wider range of conditions. EX . colonize Chesapeake & FL

Case Study : Protecting Lake Baikal

Largest Freshwater lake located in Siberia – most biologically rich lake – watershed comes from taiga

Environmental battle started in 1960 to prevent paper plants – concern of waste water and deforestation – So allow the tree – pulp operation and then send pulp elsewhere for further treatment.

Now foreign interest in timber and lake reserves.

Hope to be a model of sustainable development of watersheds.

Heat Pollution – thermal pollution

Power plants use energy from coal or nuclear to heat water to turn turbines for electricity

Cheapest way is to pull water from surface and return it.

bad – many fish die being pulled on to screens over intake pipes

Thermal temp change – decreased Oxygen

Disrupt spawning and young fish

Thermal Shock from fluctuating temp

Some call it Thermal Enrichment

increase commercial fishing season

reduces winter ice cover

an extend growing season if used as irrigation water in frost prone areas

can grow oysters and other warm water organisms in aquaculture areas

Heat nearby buildings and greenhouses ( however because of pollution of power plants usually not near housing)

Ways to reduce or control thermal water pollution

use and waste less energy

limit the amount of heated water returned

return the heated water away from shore zone

transfer heat from water to atmosphere – through cooling towers

discharge heated water into shallow ponds or canals and then reuse it

19-5 – Ocean Pollution

How much can they tolerate

Oceans are the ultimate sink

Dilute, disperse and degrade large amounts of sewage, oil, industrial waste

Marine life much more resilient than any other group

It may be safer to put hazardous waste in deep oceans

Pollutants affect on coast

Coast has most of the global population

Most polluted coast off developing countries ex. Bangladesh, Thailand, etc.

But also 85% of the sewage goes to Mediterranean Sea

US – 35% of sewage goes to oceans – black mayonnaise covers the bottoms of some bays – mixture of feces, industrial waste and oil. Especially in California

Also agricultural runoff cause algal blooms and oxygen depletion

Case Study: The Chesapeake Bay

largest estuary in United States – in trouble because of human pop.

Very shallow – receives waste from 9 major rivers and 141 smaller streams and creeks

Since 1983 – a cooperative program – CHESAPEAKE BAY PROGRAM – has taken many governmental , industries, environmental, and recreational groups and $700 million impressive cleanup has occurred

Major problem now is non native invasive.

What pollutants are dumped into the ocean

Dredge spoils – materials scraped from bottom of harbors, channels and dumped in 110 sites off the Atlantic – often laden with toxic materials.

Sewage Sludge – dumped from waste water treatment plants – not allowed in US since 1992 – however Mexico still does and currents carry the waste to Calif. Beaches

In 50 countries - merchant fleets no longer dump sewage into oceans. This wastes kill millions of sea life

London Dumping Convention of 1972 – 100 countries agreed not to dump high level radiation into the ocean. However Soviet Union has be dumping low level radiation into the artic sea.

Effects of oil on Ocean Ecosystems

Oil from crude petroleum and refined petroleum sometimes enter the ocean through accidents or on purpose

Accidents like Valdez get a lot of attention but actually US oil companies leak /spill/waste as much as 17 Valdez in the Mediterranean alone.

Kills larval forms – but evaporates quickly in warm seas

Some form tar like globs that float on surface and coat fur and feathers

Other oil sinks to the bottom and kills benthic organisms

Most sea life recovers after 3 years – takes longer in cold temp,

Considered low risk ecological problem

How can oil spills be Cleaned up

Mechanical means

Floating booms to contain the oil

Skimmer boats that vacuum up the oil

Absorbent bags or feather pillows to soak up oil

Chemical Means

coagulating methods

dispersing agents

Fire

Natural means – action of wind and waves emulsifies the oil and bacteria break it down.

These methods only breakdown part of the oil and some do as much harm – reason why P2 (pollution prevention) – is so important.

Case Study: The Exon Valdez

In Alaska – 1989 - a tanker hit submerged rocks and spilled oil – caused a spill the length of NJ – SC

Environmentalist wanted oil to come by pipeline instead of tanker because of dangers

Alyeska (company of oil exporters from alaska) did not want the pipeline it was too expensive – also was not prepared for the disaster – too little too late.

Cleanup actually did more harm than good – the areas cleaned killed more than areas not cleaned

At fault – alcoholic captiain – drunk – fatigued crew

Clean up cost $8.5 billion would have been prevented by $22.5 million double hull – now required on all tankers

P2 important because only 15% of spilled oil can be recovered

Solutions – Protecting Coastal Waters

Key – reduce the flow of pollution from land to streams to oceans

Prevention

separate sewage and storm run off in coastal urban areas

discourage ocean dumping of sluge and toxics

protect ecologically fragile and valuable areas from development, oil drilling and shipping

Double hulls for all oil tankers by 2002

Recycle used oil

Cleanup

improve oil cleanup

require at least secondary treatment of coastal sewage

19-6 Solutions – Surface Water Pollution

Non point sources

leading source in agriculture

use none or moderate slow release fertilizers on steep sloping land

Plant buffer zones of trees - Sometimes called SMZ – stream management zone

Apply pesticides only when needed

Reforest critical watersheds

Point Sources – Legal approach

Federal Water Pollution Control Act (1972) renamed CLEAN WATER ACT (1977) – make all US surface waters safe for fishing and swimming by 1983 – some progress – didn’t make the goal. Areas tested have increased from 36%(1972) - 62% in 1992.

$85 billion by government and $500 billion by industry spent – mainly on end pipe controls

Environmentalist want act strengthened by

control non point sources of pollution

phase out certain toxic discharges

provide and integrated water and air shed

permit states to take over some parts

expand private citizens ability to bring lawsuits against polluters

Some oppose want act weaken because

too restrictive and costly

want to be compensated for land/water they cannot make a profit from – takings rights

more local discretion of which water test to do

US house proposed weakening act in 1995 but bill did not pass the Senate

Point Sources – Technological Sources

Septic Tanks – in 25% of all US homes mostly rural or suburban homes with suitable soils.

tank that catches solids and allow bacteria to work on them – settle to the bottom

Water drains from top of the tank and goes to drain field – a system of perforated pipes on be of gravel

Must not be placed too close together, or in too wet of soil and should be pumped out every 3 – 5 years to prevent the settling tank from overflow

Urban areas use Sewage treatment plants

primary treatment – mechanical process that screens out debris – uses screens and polymers to remove suspended solids

Secondary treatment – biological process

-Aerobic bacteria are bubbled in and remove 90% of oxygen demanding waste

Then goes to a sedimentation tank where most of the suspended solids and bacteria (bugs) sink and are removed -–this is what is called sludge

Sludge is usually incinerated and dumped into oceans, landfills or applied to land as fertilizers.

Water is usually chlorinated too – some concern because if mixes with hydrocarbons – have chlorinated hydrocarbons in drinking water – some estimate that 7 – 10% cancers could be due to chlorinated drinking water

No radioactive isotopes or pesticides removed in this stage

As a result of Clean Water Act most cities now have Secondary water treatment plants – not all – 34 East coast cities only do primary treatment – any one want to swim?

Advanced Sewage Treatment

chemical and physical processes that remove specific pollutants.

Usually expensive to build and operate

Used in Finland, West Germany, Switzerland, Sweden

Other ways to purify water – as described at beginning of the chapter

19-5 Groundwater Pollution and prevention

Groundwater pollution – serious problem

Out of sight pollution

Low risk ecological problem – that can be high risk if ground water is drinking water.

Laws protecting ground water are weak or non-existant

Ground water can not cleanse itself because it is slow and not turbulent – pollution can not be diluted and dispersed

Takes hundreds to thousands of years to cleanse of degradable wasted because cold temp slow decomposition

Many wells – as many as 9% may be contaminated with nitrates – Good news- a small company in Germany has developed an enzyme that can convert nitrates to nitrogen gas

Many aquifers are polluted – all in NJ

FL – 92% of drinking water is ground water

Contamination comes mainly from leaking tanks and leaking land fills.

Cleaning ground water involves pumping to surface, cleaning it and pumping it back – very $$$$ - P2 very imp.

Solutions – protect ground water

monitor aquifers near landfills and underground tanks

require leak detection systems for new and old tanks

Require liability insurance for hazardous liquid tanks

Banning disposal of hazardous waste by deep injection wells and in landfills

Store hazardous liquids in above ground tanks with leak detection systems – and collect each leak

19-7 Drinking Water Quality

Is water safe to drink?

In most developed countries – yes – developing – no

1980 UN recommended – spending $300 billion to supply the world with clean drinking water and adequate sanitation by 1990. $1.5 billion /year was actually spent – not there yet –

Trying to find cheap ways to purify water ex.

Solar power UV lamp zaps water as it passes thru the tap – kills germs

Horseradish and peroxide rids water of phenols

Slime of blue green algae that remove chemical toxins.

How is drinking water purified

very similar to waste water treatment – settling – then run through sand filters and activated charcoal before it is disinfected.

How is Drinking Water Quality Protected

Safe Drinking Water At of 1974 – requires EPA to establish national drinking water standards – called maximum contaminant levels

Privately owned wells do not have to meet these standards – because of the cost to test – over $1000 per well

Have had problems in municipal water programs with cyptosporium ( caused 104 deaths in Milwaukee in 1993) and Giardia

Some want Safe Drinking Water Act weakened

eliminate national test of drinking water

eliminate the requirement of media notification

allow states to violate a standard if the state feels it is too costly

eliminate the requirement that systems remove cancer causing contaminants

Some want the Safe Drinking Act strengthened

Combine water systems – reduce administrative cost

Strengthen the public notification systems

Ball all lead in new plumbing ( now 10% qualifies as lead free)

Is Bottled Water the Answer?

No – many is dirtier than tap water

Only way to know is look for IBWA seal – cost companies $2,500/year to test for 200 chemical and biological contaminants

Home Water Purification Systems

Type Price Pros Cons

|Activated Carbon Filters |$35 – 2,500 |Removes chlorine, organic chem and radon – |Does not remove biological pathogens –|

| | | |can be breeding ground – if not |

| | | |changed or cleaned |

|Reverse Osmosis |$600 – 1,000 |Removes particulates by forcing water |Produces 4 gallons of waste for every |

| | |through semipermeable membranes |one gall produced – does not remove |

| | | |toxic chem and some pathogens |

|Distillation |$200 – 700 |Removes most everything except volatile |$ to operate, uses lots of energy, |

| | |chem and radon |produces flat tasting water |

|UV light |$300 |Kills pathogens |Does not remove other pollutants |

|Water Softeners |$1,000 |Remove dissolved minerals – |Does not remove pathogens and toxic |

| | | |substances |

best to use machines that use a variety of methods – EPA does not approve any machines – does register them

Solutions

Integrated approach to managing water resources through out each watershed and air shed.

Shift emphasis from water pollution clean up to pollution prevention

source reduction

reuse waste water instead of discharging

recycling pollutants

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