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Environmental Science:Introduction and Overview

EV20001 – Autumn 2015

Brajesh K DubeyDepartment of Civil Engineering

IIT Kharagpur

A bit about me…• Brajesh Kumar Dubey

– B.Tech (Hons) in Civil Engg; IIT, Kharagpur, India– Worked as a consulting engineer at Engineers India Limited

for 4 years, based in New Delhi– Graduate work leading to PhD from University of

Florida, USA in Environmental Engineering Sciences– Worked as Research Scientist in Florida for 2.5 years– Taught and did research in New Zealand (at UOA), at East

TN State University, USA and at University ofGuelph, Canada prior to joining IIT Kharagpur in March2015 as Associate Professor in Environmental Engineeringand Management division of Dept of Civil Engineering.

Why EVS 20001?• Supreme Court directive• Sustainable Development• India/Developing country

– Demand of resources for development activity– Need to have a balanced approach with minimum

impact on environment• As a future engineer/professional in the

country, you will have to make critical decisionsrelated to development activities

• This course will provide you basic tools which willbe helpful in making those decisions

Course Textbook

Environmental Continuum

Air

WaterLand

Ecosystem• Everything on earth is

connected– Living and non-living

things– Depend on each other– Affect each other

• Water, air, atmosphericconditions, plants, animals, soil are interlinked

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Water, Energy, Environment and Food Nexus

H2O

Enviro-nment

Energy

Food

Water and Health– 80% of diseases in developing

countries are due to the lack ofaccess to clean potable water

• Pathogens transmitted through water– Kill 25 million people every year by amoeba linked

diarrhea, cholera, and typhoid– ~3,900 children die EVERY DAY (WHO, 2004)

• 90% of 2.2 million deaths of children under 5• The most effective management intervention

– Providing safe drinking water and proper disposal ofhuman waste

Picture is from charitywater.org

Water and Health (contd.)

• Each year more than five million people die fromwater-related diseases.– A child dies from a water related disease every 15

seconds.

• 30 % of water-related deaths are due to diarrhea.• 84 % of water-related deaths

are in children age 0 – 14 years.• 98 % of water-related deaths

occur in the developing world.

www.water.org, Picture is from charitywater.org

Copyright BAN(www.ban.org)

Copyright BAN(www.ban.org)

Copyright BAN(www.ban.org)

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Why Study Environment ?

For our survival, the maintenance of theenvironment is essential. For Healthy Economy, we

need Healthy Workforce

Fresh / Clean Resources

(Water, Air, Land, Minerals)

Resource Pollution

(Leads to severe impacts)

Scope & DimensionsGrowing populations and higher standards of living putincreasing pressure on our environment. The natural world is complex and human activity canhave unexpected consequences that are hard to reverse. The study of how physical and biological processesmaintain life, and how humans affect nature, requires abroad interdisciplinary perspective.

Environmental problems and their associated solutionstypically involve social, political and economic aspectswhich the engineers and scientist must be aware of.

Course Content• Environmental Ecology• Pollution: Water Pollution• Water and Wastewater Treatment•Solid and Hazardous Waste Management• Air Pollution• Soil Pollution• Noise Pollution• Waste Minimization and Cleaner Production• Environmental Impact Assessment

Course Textbook

The Hydrologic Cycle

• Describes the movement of water in nature– evaporation, precipitation, and transpiration

• Basically, water is recycled over time• Water is a precious resource and concerns are

growing that we will run out

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Reclamation of Water

• Recovery of wastewater for reuse– industrial processing, irrigation, groundwater

recharge (State College, PA) are some indirectreuse examples

• Direct reuse for potable water is currentlydeterred, but may become reality– concerns about viruses and polar compounds

How do we treat water?

• Combine chemistry, biology, hydrology, mathand physics to:– purify ground and surface water for potable use– modify wastewater for safe discharge

Water is a Precious Resource!

Why do we need water?1. Water Supply - potable, agricultural2. Recreation - swimming, fishing3. Aquatic Life - harvesting

Three Sources of Water Contamination

1. Point Sources - industry dischargeExamples -

2. Non-Point (diffuse) - land runoffExamples -

3. Background - natural origins, varieswith geology of siteExamples -

Figure 5-2

Potable watertreatment could be“easier” if dischargeinto water bodiescould be controlled”!

How to Maintain Quality SurfaceWaters

• Water quality parameters (discharge)1. Dissolved oxygen, 4 - 7 mg/L for fish; BOD < 30 mg/L2. Solids concentration, lower is better, < 30 mg/L3. Coliform bacteria, lower ensures safe consumption4. Toxic substances, heavy metals, pesticides, etc.5. Nutrients – NO3

-, PO4=

5. pH, 6.5 - 8.5

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What if we Fail?

• Eutrophication– Defined as the accelerated fertilization of

lakes, reservoirs, streams, and estuaries arising frompollution associated with population growth, industrialdevelopment, and intensified agriculture

• Why is this of concern?• Algal blooms

• 2-methylisoborneol, cyanotoxins• Death of water body

Effects of Eutrophication

• Unbalance the system– (i.e., aquatic food chain)

• Abundance of nutrients heavily increasesblue-green algae– increases turbidity – decreases photosynthesis– increases malodors – MIB, geosmin– Decaying algae reduces DO

Remedial Actions (Eutrophication)

• Reduce nutrient input into water body

• Focus is on “P” ?– Why?

• Copper sulfate - used to control algalblooms, but poisons fish– Southern California owns a helicopter to spread

CuSO4

Water Quality Standards Reduce NegativeImpacts on Water Bodies

• Effluent Standards - maintain surface waterquality– NPDES - National Pollutant Discharge Elimination

System (WWTP)– BOD: < 30 mg/L for the 24-hr composite

mean collected over 30 days< 45 mg/L for arithmetic 7-day mean% removal > 85%

– Suspended Solids - same as BOD

Water Quality Standards (continued)

– Oil and Grease: < 10 mg/L (30-day mean)< 20 mg/L (7-day mean)

– pH, between 6 and 9– Toxic pollutants – varies– Non-conventional pollutants

• Nitrogen – varies based on ammonia vs. nitrate• Phosphorus - ~1 mg/L

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“Water Quality in the News”

• Phosphorus < 1.0 mg/L to preventeutrophication (e.g., Everglades)

• Endocrine disrupters / Pharmaceuticals– Atrazine and bisphenol (EDCs)

• Tastes and Odors

NPDES Pretreatment Program

• Prevent industries from discharging pollutants thatadversely affects treatment operations

• Becoming more of an issue because of polarcompounds and beneficial reuse programs

• Is NPDES applicable to potable water treatment?

EPA Based Technologic Standards-Wastewater

• Best Conventional Pollutant ControlTechnology (BCT)– secondary treatment to control conventional

pollutants• Best Available Technology Economically

Available (BATEA)– control toxic substances and nonconventional

pollutants if the owner can afford it (ex. granularactivated carbon)

Microbiological Quality of DrinkingWater

• Treatment with physical (filtration andcoagulation) and chemical (chlorine) techniquesto remove pathogens

• Effective coagulation & filtration defined by aturbidity <0.5 NTU in 95% of measurements

• Maximum contaminant level goal (MCLG) forcoliforms, giardia, and crypto is zero– What is the difference b/w MCLG and MCL?

Groundwater Quality

• More than 50% of world population relies ongroundwater as a source of drinking water

• Groundwater contamination1. Natural - dissolved

salts, iron, manganese, fluoride, arsenic, radionuclides,trace metals

2. Subsurface - septic tank adsorption fields3. Industrial - deep well injection

– Environmentally acceptable?

4. Agriculture - soil filtration

Chemical Quality of Drinking Water

• Treatment to meet Standards

• New chemicals can and will be added• Standards based on adverse health effects

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Inorganic Chemicals

• Arsenic, barium, cadmium, chromium, mercury, selenium, thallium - internal organs

• Lead toxicity effects red blood cells, nervous system &kidneys

• Copper - nausea & vomiting• Fluoride - excess can cause fluorosis (teeth)• Nitrate - excessive ingestion can cause

methemoglobinemia in infants• Asbestos - pulmonary fibrosis / bronchogenic

carcinoma

Organic Chemicals

• Volatile organic compounds (VOC) -carcinogenic

• Synthetic organic chemicals (SOC) - pesticidesgreatest concern– neuralgic effects and carcinogenic

• What is a difference b/w VOCsand SOCs?

Disinfection By-Products

• Produced from chemical interactions betweenchlorine and natural organic substances(carcinogenic) – WHAT?

• Trihalomethanes (THMs) - organohalogens where 3of the 4 H atoms of methane are replaced withchlorine, bromine, or iodine (e.g., chloroform)

• Haloacetic acids (HAA5)

Radionuclides

• Radioactive elements decay by emittingalpha, beta, or gamma radiations caused bytransformation of the nuclei to lower energystates (e.g., radon)

• Potential health issues areteratogenic, genetic, and somatic

Secondary Standards

• Secondary maximum contaminant levels(SMCLs) - no adverse health effects– for aesthetics– nonenforceable by federal regulator

• 2-methylisoborneol - not a SMCL, but impartsobjectionable tastes and odors

• MTBE - imparts tastes and odors

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Demand for and Use of Water Water Consumption by Sector

Irrigation , 81%

Livetock, 3%, 0

Thermoelectric,3%

Domestic, 7%

Commercial, 1%

Industrial, 3%

Mining, 1%

Others, 16%

Worldwide Water Withdrawals

• Agriculture consumesthe largest share offreshwater

– Industry is a major consumerin North America andEurope.• More efficient irrigation

systems• Industrial economy

– Africa, Asia and LatinAmerica• Agricultural economy• Irrigation systems not always

efficient• Booming economy

(China, India, Brazil) willinfluence the ratio.

Increasing Withdrawals and Consumption

Individual Use• A person needs 4 to 5 gallons of water per day to survive.• The average American individual uses 100 to 176 gallons of water

at home each day.• The average African family uses about 5 gallons of water each day.• Middle Eastern and Northern African (MENA) countries are in

absolute water scarcity situation (< 500 m3/person/day).– Kuwait has the least per capita water availability.

• 27 m3 in 1970, 9 m3 in 2001 and projected to decrease to 5 m3 in 2025

– Yet Kuwait has the highest per capita water consumption.• 200 liters per person per day in the 1980s• Currently 500 liters per person per day

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Water Consumption in Major Cities

• The world is urbanizing.– By 2050, 70% of the world’s population will live in

urban areas.– In developing countries, cities grow by 5 million

residents every month.– Expansion of slums– Infrastructure does not keep up with the pace of

expansion.• Lack of access to water and adequate sanitation

WWF (2011) Big Cities, Big Water, Big Challenges

Water Consumption in Major Cities• Mexico City, Mexico

– Over 21 million people in the metropolitan area– Domestic water use: up to 364 l/person/day

• Buenos Aires, Argentina– Over 12 million people in the metropolitan area– Domestic water use: 378 – 400 l/person/day

• Shanghai, China– 23 million inhabitants– Domestic water use: 411 l/person/day

• New Delhi, India– Over 20 million inhabitants– Domestic water use: 78 l/person/day (Shaban and Sharma, 2007)

WWF (2011) Big Cities, Big Water, Big Challenges

Water Requirement/Use• Virtual water

– Water embedded in food products– 1,000 liters for one kg of grain– 15,500 liters for one kg of beef

• Meaty American and European diets– 5,000 liters of water/day

• Vegetarian African and Asian diets– 2,000 liters of water

• Meat consumption in China– 20 kg per year in 1985– 50 kg per year in 2009– Equivalent to 390 km3 = Total water

use in Europe• Shift in dietary habits is

almost impossible toreverse.

http://www.economist.com/world/international/displayStory.cfm?story_id=13447271http://technology.newscientist.com/data/images/archive/2540/25401501.jpg

Food Waste is Water Waste

Godfray et al. (2010) in SEI (2011)

Food Loss and Waste

FAO (2011)

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Water and Energy

WaterEnergy

Security•Food, military, energy

Business•Opportunities, costs, ri

sks

Environment•Agriculture, forest, clim

ate

Justice•Pricing, ownership, equ

ity

Policy

SustainableDevelopment

•Sanitation, health, poverty, gender

Energy and Water

• Energy consumers– Supply and conveyance– Wastewater collection and

treatment– Treatment– Distribution– Wastewater discharge

• Some factoids– Electricity = 75% of

municipal water processingand distribution cost

– 4% of US power used forwater supply andtreatment

Water and Energy

• Energy production needs a lot of water– ~ 25 gallons per kWh– ~ 39% of freshwater withdrawals in USA (excluding

hydropower demand) are for thermoelectricplants (136 billion gallons per day).

Water Use for Energy Production• Electricity production is one of the largest users of water. [Example: For a

60-watt incandescent light bulb burning for 12 hours a day for a year in111 million houses, a power plant would consume about 655 billion gallonsof water.]

• Water use efficiency (Virginia Tech Study, 2008)

– Natural gas 3 gallons/million BTU– Hydroelectric 20 gallons/million BTU– Coal 41 to 464 gallons/million BTU– Liquid natural gas 145 gallons/million BTU– Nuclear 2,400 to 5,600 gallons/million BTU– Fossil fuel thermoelectric 230 to 270 gallon/million BTU– Ethanol 2,500 to 29,100 gallons/million BTU– Biodiesel 14,000 to 75,000 gallons/million BTU

• Biofuels – an irony when it comes to water– Currently 2% irrigated water used for energy crops– If all plans were implemented, 180 km3 of water will be needed.

Electricity consumes 20% of waterexcluding agriculture

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Hydraulic Fracturing• Natural gas is projected to increase by 30% over the

next 25 years.• Over one million wells have already been hydraulically

fractured since the 1940s.• An estimated 35,000 wells are fractured every year.• Hydraulic fracturing uses a mix of water, sand and

chemical additives.– Used on 90% of wells in the US

• Water intensive process– 2.3 – 4.8 million gallons per well– Once used, the water is extremely polluted and has to be

treated prior to disposal.

Water-relatedConcerns with Fracking

• Water withdrawals– Water used in fracking may be

competing with other uses.• Groundwater contamination

– Drilling and production• Proper treatment of wastewater• Truck traffic and impact on water

quality• Surface spills• Stormwater management

WATER SECURITY

Water Security: Definition

• Access at all times to sufficient and quality waterto satisfy varied needs

• Water security is built on three pillars:– Demand for and Use of water: Appropriate use based

on the knowledge of quality water and treatment– Availability/supply of water: Sufficient quantities of

water available on a consistent basis– Access to water: Having sufficient resources to obtain

appropriate quantities of water for satisfying needs

Space-Time Dimension

• Space– Individual family unit– Village, town, district, state, province– Country, continent, globe

• Time– Season (winter, spring, summer, fall)– Year to year variation in climate and impact on supply– Long-term, medium-term, short-term

• Need/demand/quantity/quality• Social/cultural influence

Factors Impacting Water Security

• Burgeoning population• Massive migration of people from rural areas to

urban centers• Rising standard of living• Growing energy demand• Intensifying agriculture• Increasing industrialization• Increasing water consumption• Global Warming and Climate change

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Water, Energy and Food SecurityNexus

SEI (2011)

Sustainability of Water Security• The integral product of three factors

Implications of Climate Change

• Food Security• Water Resources• Energy Production• Extreme Hazards• Ecosystems• Human Society• Ecosphere• Biosphere

Implications of Climate Change (Contd.)

• Rising temperature: 2 degree C during the next100 years

• Water use: changes in the way plants grow• Reaction of trees to downpours• Drying up of biomass during droughts• Rapid growth of crops and then wilting• Intensification of hydrologic cycle

Climate Change and Hydrology

IPCC [2013], AR5 WG I – Fig. 11.11

Hydrologic Impacts of Climate Change

• Increase in frequency of droughts– Drought in Texas in 2011 or ongoing drought in the Midwest

• Extreme events may become more frequent.• Decrease in snowpack and change in the timing of runoff in

mountains in North America• Replacement of tropical forests with savannah in eastern Amazonia

– Changes in water availability for human consumption, agriculture, andenergy generation

• Increased risk of inland flash floods in Europe, glacial retreat inmountainous areas, coastal communities at risk from sea level rise

• Increase in the number of people exposed to water stress inAfrica, reduction in yields from rain-fed agriculture

• Decrease in freshwater availability in Asia, coastal areas at risk dueto increased flooding, rise in droughts in some regions

climate.nasa.gov/effects

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GLOBAL WATER SITUATION

What is the Global Water Situation?

• Local water shortages are multiplying.• Current patterns of use and abuse-the amount being

withdrawn dangerously close to the limit and evenbeyond

• An alarming number of rivers no longer reach the sea:• The Indus, the Rio Grande, the Colorado, the Murray-

Darling, the Yellow River-the arteries of main graingrowing areas

• Severe and long droughts in Australia, India, Brazil andSouth America• Two years ago hydroelectric power plants did not have

enough water to drive turbines and there were repeatedbrownouts.

Global Water Situation: What ishappening (contd.)?

• Freshwater fish populations are in precipitous decline• Fish stocks have fallen by 30% (WWF for Nature), larger

than fall in populations of animals in any ecosystem.• 50% of world’s wetlands have been drained, damaged

or destroyed in the 20th century.• Fall in volume of freshwater in rivers: Invasion of

saltwater in delta, changing in balance betweenfreshwater and salt water

• Excess pumping of water from rivers feeding Aral Sea inCentral Asia led to its collapse in 1980.

• Global water crisis: Impact on supplies offood, generation of energy, and other goods.

Per-Capita Freshwater Availability(2000)

Global Water Stress1995

State Parameter 1995 2025Population 270 mn 2.3 bn

# of Countries 11 15Population 166 mn 1.7 bn

# of Countries 18 39

Stressed

Scarce

2025

Water Stressed River Basins

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Absolute Scarcity for 1 billion People by 2025(Many countries will import > 10% of cereals) Intensifying water scarcity

Declining water tables-focus on consumption

Water Scarcity: Causes

• 80% is attributable (Vörösmarty et al. 2000) to:– Population rise;– Higher food and energy requirements leading to

higher water requirements; and– Economic development (changing habits/diets).

• In the last 50 years– Population: from 3 billion to 6.5 billion– Water use: Tripled

• Projections: 2025 & 2050– Population: Increase by another 2 billion and 3 billion– > 50% people will be water stressed or scarce.

World Population Evolution

Global Urban Population Trend Engineering Water Security

Supply Demand

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Sustainable Water SupplyManagement

• Integrated management of demand, supply, anduse

• Integrated management with simultaneousconsideration of:– Reduction in water consumption– Recycling of water– Reuse of water– Conservation of water– Efficient use of water– Proper management of water

Sustainable Water Supplyand Use

WATERSUPPPLY

CONSER-VATION

EFFICIENT USE

TREAT-MENT

RECYCLE

REUSE

DEVELOPADDITIONAL

SOURCES•DESALINATION

Emerging Technologies: Water• Water is limited and should not be wasted• Water conservation

– Every drop conserved is a drop that can be used for otherpurposes

• Efficient irrigation– Improve irrigation methods so that every drop counts and does

not go wasted• What is required:

– Determine crop water needs– Crop area, crop type, soil type, climate, irrigation methods and

frequency– Develop tools that can be used to optimize water use

• Water treatment

Where are we headed as a society?• Development to management

– Paradigm shift• Scientific and technological progress• Social progress: Value system• Changes in global demographic landscape• Human nature

– Conflicts and wars– Competition– Convergence or divergence

• Integration of engineering, technology, socio-economic-political science