water pollution. water: hydrologic cycle and watersheds types of water pollutants –pathogens...

Water Pollution

• Water: hydrologic cycle and watersheds

• Types of Water Pollutants

– Pathogens

– Organic Waste

– Chemical Pollutants

– Sediments

– Nutrients

• Eutrophication

• Anoxic Gulf Coasts Waters (a.k.a. The Dead Zone)

• Sewage

• Clean Water Act

• Safe Drinking Water Act

WHAT YOU SHOULD KNOW - TOPIC OUTLINE

Water Pollution• CONSEQUENCES

– Health hazards: many pathogens are waterborne and are highly correlative to poor water quality..

– Loss of biodiversity = polluted water bodies or ones with excess organic and/or nutrients become anoxic and almost abiotic.

– Loss of aesthetic beauty

– Impact on leisure and other outdoor/sporting activities

Hydrologic Cycle• Water migrates

between the atmosphere, the soil, and underground.

• When examining the different types and sources of water pollutants, put them within context of the Hydrologic Cycle.

Review the Hydrologic Cycle

Water on the surface can do one of four things: a. evaporate back to the atmosphere

b. percolate into the ground to become ground water

c. run-off to bodies of water downstream d. become part of a glacier

Watersheds• Watershed = area that shares

a common drainage network.–Fluids (runoff, chemical spills,

etc.) on the landscape move downstream, aggregating in larger and larger channels. –Pollution in one location,

especially if released in the upland areas, may contaminate the entire watershed due to the interconnectivity.

Watershed of the Red River

EAST CACHE CREEK

Mississippi Watershed

Pollution• Pollution = “the presence of a substance in the environment that, because of its chemical composition or quantity, prevents the functioning of natural processes and produces undesirable environmental and health effects” - EPA

point/non-point sources• Pollution can be further subdivided into

two sub-classes based on the source:– Point source = discharges of substances

from factories, sewage, industry, etc.. The source is easy to identify, and thus regulation of point source pollutants is manageable.

–Non-Point source = the sources of this type of pollution is very difficult to identify. Non-point pollution (NPS) often originates from agricultural and urban runoff, rainfall and snowmelt, storm-water drainage, and atmospheric deposition. Because the source regions are unidentifiable, NPS are extremely difficult to manage.

Point Source and Non Point Source Pollutants

Types of Water Pollutants

• The water pollutants that we will discuss in this lecture include:

– Pathogens - disease causing (bacteria, protists, round worms, flat worms, viruses)

– Organic Waste - sewage

– Chemical Pollutants - industry, mines

– Sediments - deforested areas, farms, mountains

– Nutrients - agriculture fertilizers

Pathogens

• “The most serious water pollutants are the infections agents that cause sickness and death” .

• Waterborne diseases kill thousands of people per year. The majority of these pathogens are a result of contaminated water – unsanitary water associate with poor hygiene.

Disease Pathogen

Typhoid fever salmonella bacterium

cholera bacterium

diarrhea bacterial & protozoan

Hepatitis viral

dysentery bacterial & protozoan

Giardiasis protozoan

parasitic diseases

intestinal worms, Guinea worms, etc.

• Pathogens are related to poor sanitary conditions, often a result of organic pollution

• Human and animal excrement in water bodies creates a suitable environment for these pathogens–The fluid medium allows for quick

transmitting

–People bathing or drinking in contaminated streams are exposed to these pathogens

Organic Waste• Human and animal waste creates “serious

problems”

• Besides creating a pathogen-friendly environment, excess organic wastes reduce the availability of dissolved oxygen in water.

– aerobic bacteria and other decomposers breakdown organic materials they consume oxygen through cellular respiration. More organic waste results in more aerobic decomposition, which ultimately lowers available oxygen.

• Biochemical Oxygen Demand (BOD) = measure of the amount of organic material in water in terms of how much oxygen will be required to break it down. The higher the BOD the greater is the likelihood that dissolved oxygen will be depleted.

Organic Waste, Animals

• Animal Feeding Operations, colloquially referred to as “Factory Farms” contain large quantities of livestock.

• The high concentration of animals generates a lot of waste. Some animals, such as hogs, produce substantially more excrement per pound than humans.

• The animal waste poses serious threats to the environment. It is high in organic materials, nutrients, heavy metals, and pathogens

Examples of AFO’s

• Stockyards

• Hog Houses

• Chicken Houses

www.ecohealth101.org/whats_left/eat3.html

http://www.goveg.com/photos_chicken11.asp,

‘Animal Feeding Operations’

• Animal Feeding Operations (AFO) are defined as “a lot or facility (other than an aquatic animal production facility) where – “Animals have been, are, or will be stabled or

confined and fed or maintained for a total of 45 days or more in any 12-month period, and

– Crops, vegetation, forage growth, or post-harvest residues are not sustained in the normal growing season over any portion of the lot or facility” (epa.gov).

• AFO’s are treated as a point source of organic and nutrient pollution

Waste Lagoons• Waste from the AFO are

hosed into waste lagoons.

• Ideally within the lagoons the solids become concentrated as the water evaporates. The manure can then be used as a fertilizer.

• These waste lagoons can leak into the environment contaminating surface and ground water with organic waste, nutrients, heavy metals, and pathogens

Photo Source: Dairy Waste Pictorial, EPA Region 10 and Washington State Dairy Federation

http://lwcd.org/images/MCR_earthen_Waste_lagoon.JPG

Leaching?

Hog Farms in North Carolina• The heavy rain

from Hurricane Floyd (1999) flooded many of the waste lagoons, and the organic pollution washed out across the landscape,

• Getting back to the watershed concept, where did all the flooded waste lagoon materials go?

Source: North Carolina in the Global Economyhttp://www.soc.duke.edu/NC_GlobalEconomy/hog/maps.php#map2b

Flooded hog farms after Hurricane

Floyd. •The waste

lagoons were inundated,

polluting the local

watershed and the nearby

coastal waters.

Human Waste, Hurricane Katrina

• Images of a flooded New Orleans. The water that inundated the streets was full of waste.

news.nationalgeographic.com/.../photo8.html

news.nationalgeographic.com/.../photo8.html

Fecal Coliform• Organic material such as excrement is

decomposed by Fecal Coliform (FC) bacteria such as certain strains of E. coli and other bacteria.)

• Their presence in the water indicates contamination by excrement.

• The EPA measures FC concentrations as an indicator of water quality.

• Other strains of E.Coli from organic waste are more harmful, such as the recent outbreak of E. coli in spinach.

Chemical Waste• “Water-soluble inorganic chemicals constitute an

important class of pollutants that include”

– Heavy metals (lead, mercury, cadmium, nickel)

– Acids from mine drainage

– Road salts

– Petroleum

– Urban runoff

– Pesticides, fungicides, herbicides

Tar Creek, Oklahoma

CERCLA (SUPERFUND)

Chemical Pollutants

• Any noxious substance spilled on the landscape can contaminate the watershed. Toxic pollutants sometimes have very long residence time and can be very problematic to manage.

• The most problematic to manage is contamination of the groundwater.

Groundwater Contamination:

What is on the surface that could contaminate the

groundwater?

Sediments• All streams transport some degree of

sediments.

• Development or construction within the watershed can increase the amount of sediment in streams.

• Excess sediment will “choke the stream”

• The environmental effect is loss of biodiversity, change in hydrology, and ruining the aesthetic beauty of the water body.

• Sediments also act as surface area for other pollutants, like heavy metals. So greater concentrations of sediments will directly result in higher concentration of other pollutants.

Fish are all dead! No light = no vegetation and the whole ecosystem dies.

Nutrients• Naturally, nutrients are limited within

many aquatic ecosystems. Plants often have to compete for nutrients.

• Phosphorus and Nitrogen are two very important nutrients that are usually in high demand by aquatic vegetation. Both these elements are in the building blocks of biological molecules (DNA, Protein, Fatty Acids).

• Aquatic systems with too many nutrients become eutrophic.

Eutrophication• Phosphorus and nitrogen in many aquatic systems are usually

limiting.

• Aquatic vegetation exists in two general forms:

– Benthic = rooted in the substrate, usually multicellular vegetation

– Planktonic = free-floating in the water column, often single celled algae

• In nutrient poor environments the benthic organisms have an advantage over the planktonic. Because they are rooted they can draw upon nutrients within the sediment.

• Nutrient-poor aquatic ecosystems are called oligotrophic, which translates to “poorly fed”. It seems paradoxical that a poorly fed environment is usually the most biologically diverse.

Aquatic Vegetation

Eutrophication• The excess nutrients stimulate the

growth of the plankton at the expense of the benthic vegetation. Being single-celled and having an r-strategy, planktonic algae can rapidly respond to an influx of nutrients within the water column.

• The algal populations explode (the carrying capacity jumps dramatically).

• The abundance of algae decreases the biological productivity of the aquatic ecosystem

Eutrophication Continued• Planktonic algae can form a thick scum surface

that blocks out light to the benthic species.

• In addition the algae blooms result in lots of dead algae . The dead algae along with the dead fish and other organisms creates an abundance of organic materials. This is broken down aerobically, which depletes the dissolved oxygen in the water.

• Once the dissolved oxygen is reduced very few organisms can survive in this hypoxic environment.

Eutrophic Pond

Eutrophic_pond.JPG (84KB, MIME type: image/jpeg)

From Wikipedia

Dead Zone

• The “Dead Zone” is an area of hypoxic water that stretches along the Gulf Coast.

• The Mississippi River drains 31 US states and 2 Canadian provinces. It is one of the largest rivers in the world, and it drains the world’s best agricultural lands. The runoff of fertilizes from along the Mississippi River watershed empties into the Gulf of Mexico where it stimulates an algal bloom.

Dead Zone (hypoxia)

http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/OCDST/dead_zones.html,

Dead Zone

Historical Context of Sewage

• Important note: prior to the 1970’s most of the raw sewage, the stuff coming out of the houses, was simply dumped into the environment – usually within rivers or oceans.

• Clean Water Act (1972).

• The Clean Water Act (CWA) helped establish modern sewage treatment by appropriating funds to local and state governments to build or revise existing plants.

Sewage Treatment• The raw sewage contains at least these

four components:

–Debris (toilet paper, feminine products, other things that get flushed)

– Particulate organic mater

– Colloidal dissolved organic mater (things in solution or partial solution, like urine

–Dissolved Chemicals

Primary Sewage Treatment

(Mechanical)– Preliminary Filtration = the raw sewage flows out of your house to a sewer line, which eventually leads to a municipal treatment plant. In the preliminary stage the raw sewage is filtered through a mesh. The solids and paper that accumulates on the mesh screen is raked off and transported to an incinerator or taken to a landfill.

Sewage Treatment• Primary Stage = The raw sewage flows to

a circulation chamber. Here the sewage is slowly circulated – the change in the velocity causes the courser materials, such as grit and other bits of organics, to settle out. The stuff that settles at the bottom is referred to as sludge; it is removed and taken to a landfill by dump trucks. In addition, grease, fats, and oils will float on the surface. These fatty materials are siphoned off and merged with the sludge.

biological & chemical treatment• Secondary Treatment = Remaining

dissolved organics and nutrients are broken down via aerobic decomposition. The sewage is aerated with oxygen and decomposing bacteria are added. The bacteria “feed” on the organic materials left in the water and use the remaining nutrients.

• The water is then sterilized, by either chlorine, UV radiation or ozone gas. Then it is released back into the environment. Usually municipal treatment facilities pump the treated sewage into a river or pump it out into the ocean. Water exiting the sewage treatment facility (gray water) in many places is cleaner than that which comes out of your tap.

Secondary Treatment

Gray Water

• In many cities the water exiting the sewage treatment plant is reused. Some cities use gray water to water lawns.. However in major metropolitan areas where water is scarce – the desert west – gray water might be an option for drinking water.

Septic System• Waste leaving the home flows

through a septic tank. In the tank the solids settle towards the bottom. Here the organics breakdown through aerobic and anaerobic decomposition. The colloidal and dissolved inorganics flow out into the yard via a drain field. The effluent is filtered naturally? by the lawns, gardens, and soil microbes.

Drain Field

Sewage Ponds• Many newer communities are using

sewage ponds to treat their waste. The sewage ponds also employ biological decomposition. In this case the raw sewage is pumped into a containing pond. The solids accumulate at the bottom of the pond. The organic materials are feasted on by decomposers. Aquatic vegetation is also planted. The vegetation uses the organics and nutrients as fertilizers.

Clean Water Act 1972

• The Clean Water Act is the sister of the Clean Air Act. It was the first legislation of its kind to protect the Nation’s waters and to create safe drinking water.

Clean Water Act• During the Environmental Movement

there was a push to clean up polluted water. This was in large part due to:

– Accumulating sewage

– Factory effluents from the Chemical Revolution

– People getting sick from polluted water

– The Cuyahoga River caught fire in 1967

Clean Water Act 1972• The Clean Water Act:

– Gave the EPA the power to set regulations on sewage effluent

– Appropriated funds to local governments to retool poorly working sewage treatment

– Gave power to the EPA to regulate the amount of pollutants emitted by factories

– Protected the US waterways (“Navigable Waterways”). Under this definition wetlands are designated “navigable waterways”, and the CWA gave power to the Army Corp of Engineers to protect wetlands.

• The Safe Drinking Water Act 1974 (from the same vein as the CWA) authorized EPA to regulate the quality of public drinking water and to set drinking water standards

Strategies

• Two basic strategies to managing the pollution are:

–1) to reduce or remove the source

–2) to treat or purify the tainted water

water-related laws

• CERCLA

• CLEAN WATER ACT

• SAFE DRINKING WATER ACT

• GENERAL MINING ACT 1872

• SURFACE MINING CONTROL & RECLAMATION ACT

COMPREHENSIVE ENVIRONMENTAL

RESPONSE, COMPENSATION, &

LIABILITY ACT (CERCLA) aka SUPERFUNDNot water specific

Regulates industries hazardous waste

Requires cleanup of abandoned hazardous waste

sites

CLEAN WATER ACT - 1972Unlawful to discharge any

pollutant from a point source into navigable

waters without a permitSets standards for

wastewater treatmentEnforced by EPA

SAFE DRINKING WATER ACT, 1974Sets standards for drinking water and

establishes protection for drinking water and its sources (rivers, lakes, reservoirs,

springs and ground water wells)

Many bottled waters are from municipalities tap. These may have higher

quality standards than imported bottled water.

SURFACE MINING CONTROL AND RECLAMATION ACT, 1977

Sets environmental standards for the

operation and reclamation of mines and

prohibits mining on certain lands.

GENERAL MINING ACTSet price of a claim on government land between $2.50 to $5.00 per acre. This

encouraged migration to the west.BUT

Large mining companies extract about $2.5 billion from public lands annually

Applications for claims managed by the Bureau of Land Management, which in 1994

dramatically reduced the claims accepted.Bills to change this law have not been acted on

by Congress