WATER POLLUTION

1. WATER POLLUTION APES Moberg

2. A water pollutant is any substance that decreases the quality of water

3. Only 3% of all water on earth is freshwater • As pollution of freshwater increases, the amount of usable freshwater decreases. • The primary water pollution problem in the world is the lack of disease free drinking water

4. Many types of pollutants can enter our waterways • Common pollutants include • Acid mine drainage • Agricultural and urban runoff (animal waste, nutrients, pesticides and herbicides) • Sewage • sediments • Heat (thermal pollution) • Heavy metals • Oil and gasoline • Leachate from landfills

5. Two major classes of pollutants • POINT SOURCE • Can be traced to their single, stationary source such as a pipe • Sewage spills from a treatment plant, dumping from cruise ship or septic tank are point sources • NON POINT SOURCE • Cannot be traced to a specific stationary source; but is diffuse and mobile • Urban and agricultural Runoff are non-point sources

6. Practice question • Of the following which is the best example of a point source of water pollution? a) Factory effluent b) Storm water c) Acid precipitation d) Agricultural run off e) Residential pesticide runoff

7. Sewage is the waste (used) water from residential and commercial buildings. It is a mixture of various substances Sewage can enter groundwater via leaks from underground septic tanks in rural areas Untreated sewage can enter surface water with storm water runoff during heavy rains in urban areas when treatment plants become overwhelmed Sewage carries pathogens such as viruses and bacteria; excessive nutrients such as NITRATES and PHOSPHATES; fats, oils and grease; prescription drugs to stream water Sewage pollution also increases total dissolved solids (sediments), fecal coliform bacteria and heavy metals Water pollutant: RAW SEWAGE

8. Table 12.1

9. SEWAGE REGULATIONS (Clean Water Act) Laws typically have limits of intestinal bacteria that can be in surface waters. These pathogens get into aquatic systems through untreated sewage or overwhelmed systems in storm water runoff. US EPA regulations for swimming waters: Geometric mean <200 fecal coliforms/100ml US EPA regulations for drinking water: Maximum contaminant level: 1 fecal coliform cell/100mL

10. WHY IS SEWAGE A PROBLEM? HEALTH consequence (social impact of sewage pollution) Bacteria and viruses present in sewage effluent → bathers are at increased risk of contracting illnessesspread through fecessuch as cholera, Hepatitis A, typhoid fever, diarrhea and intestinal distress (cramps, vomiting), ear infections • Shellfish grown in sewage contaminated waters may cause food poisoning • →mussels and oysters can accumulate human pathogens through their filter feeding apparatus.

11. WHY IS SEWAGE A PROBLEM? ECONOMIC consequence Sewage debris (e.g. condoms, diapers, tampons, rags) accumulate on beaches • →loss of tourism dollars due to beach closure and lowered aesthetic appeal • → expense of cleaning up beaches • →ALSO closure of shellfish beds due to sewage contamination or sewage induced HABs (harmful algal bloom)/ hypoxia can lead to high loss of income and closure of businesses.

12. WHY IS SEWAGE A PROBLEM? ENVIRONMENTAL consequence Sewage is primarily organic in nature and subject to bacterial decay. It increases BODand nutrients in the water, ultimately leading to HYPOXIA and lower biodiversity Bacterial decay also involves the breakdown of proteins and other nitrogenous compounds releasing ammoniaand hydrogen sulfide gas Even low concentrations result in massive fish kills ALSO suspended solids in sewage may smother river and sea beds, preventing respiration of benthic (bottom dwelling) flora and fauna, again lowering biodiversity

13. Preventing sewage pollution is more effective than trying to remove it • Using separate storm water and sewage sewer systems help to prevent overflow during a storm. • Maintaining sewer lines by routinely checking and replacing aging infrastructure prevents leaks into groundwater • Though not sewage, Picking up pet waste and providing baggies for waste in public areas prevent animal waste from entering surface water through storm drains. Pet waste carries many of the same pathogens as human feces

14. Animal waste is a huge problem with industrial-sized livestock farms called CAFO: Concentrated Animal Feeding Operations 4. Farms with hundreds of animals should dispose of the manure in waste lagoons (retention ponds) FAR from surface water bodies, such as rivers. Lining the ponds with plastic and impermeable clay will prevent pollution of groundwater 5. Manure could also be harvested and sold for use as biofuel or soil fertilizer

15. Water pollutant: nutrients • Nutrients, such as N and P, enter waterways through non-point source runoff from manure, fertilizers and septic tanks (sewage) or treated wastewater • STEPS TO EUTROPHICATION: • Nutrients cause an immediate increase in algal growth; plants grow, die and are decomposed by bacteria. This is called eutrophication • Bacteria consume a lot of dissolved oxygen in decomposing dead plant material causing HYPOXIA, • Low oxygen levels cause macroinvertebrate and fish kills because they cannot respire

16. Eutrophication causes DEAD ZONES in the Gulf of Mexico

17. PRACTICE QUESTION • Which of the following will result in accelerated eutrophication when introduced into streams, lakes and bays? • Bacteria and viruses • Pesticides • Herbicides • Phosphates • Acid wastes and salts

18. Oxygen sag curve shows the effect of eutrophication in a stream • THE CAUSE: Sewage (immediately) and nutrient pollution (after the algae die ) which increase the BOD • THE EFFECT: Decomposing bacteria then decrease the DO levels in the stream (hypoxia) • THE CONSEQUENCE: lower biodiversity since many organisms cannot respire, increased odors and even coral bleaching

19. Other impacts of nutrient pollution REDUCED LIGHT PENETRATION High concentrations of algae in surface water increase the turbidity, reducing the amount of light reaching bottom dwellers, reducing photosynthesis and productivity Particularly a problem for coral which are typically found in Oligotrophic water with good light penetration. Eutrophication reduces amount of photosynthesis of the algae living in coral and causes coral bleaching

20. Other impacts of nutrient pollution • CHANGE IN SPECIES COMPOSITION As nutrient tolerant plants and algal species proliferate, they displace more sensitive species and change the composition of the community. A survey of the macroinvertebrates in the stream can indicate pollution if only the most tolerant species are found there. Mayflies, stoneflies and caddisflies can only survive in clean water

21. More impacts of nutrient loading • HEALTH IMPACT Drinking groundwater or surface water with nitrate contamination results in BLUE BABY syndrome which is potentially fatal to infants under 6 months old. Nitrates are converted to nitrites in the stomach and lead to methemoglobin, a blood disorder aka blue baby syndrome The Clean Water Act does not allow Nitrate levels above 10ppm for drinking water

22. Cultural eutrophication is also caused by phosphates, from sources shown below.

23. PRACTICE QUESTION • Identify TWO ways agriculture adds nitrogen to waterways today. • A) pesticides and manure • B) fertilizers and manure • C) sediments and herbicides • D) eutrophication and animal waste

24. Preventing nutrient pollution • Wetland and riparian plant communities can filter nutrients from farms or urban runoff (carrying fertilizer or pet waste). Plants, algae, denitrifying bacteria directly uptake nutrients. Some can be adsorbed by wetland soils, then used by plants or bacteria. • Building more wastewater treatment plants or composting toilets for individual buildings also reduces sewage load in waterways. Small centralized plants reduce the need for many septic tanks in rural areas, each with the potential to leak and contaminate the groundwater supply.

25. Construction, road building, logging, mining and soil erosion from agriculture can cause large quantities of sediment (sand, clay, silt) to enter the water. Removing trees cause an increase in erosion since roots are not there to anchor soil. More sediment washes into streams. EFFECTS: Sediment buildup reduces the ability of waterways to control floods by lowering the capacity to store water and additional sediments from runoff Stream turbidity increases, blocking sunlight, lowering primary productivity (especially true for coral reefs!) Sediments are darker colored than the water and so cause heatingby absorbing additional sunlight Sediments can lower biodiversity by blocking fish gills and burying benthic organisms, suffocating them Water pollutant: sediment

26. Wetlands and sediment fences can trap about 80 to 90% of sediment from runoff and construction. The roots of plants can prevent erosion or trap sediments from land sources. Preventing sediment pollution

27. Water pollutant: salt, sand, petrochemicals and heavy metals from roads Zinc and copper are released from cars: brakes release copper, while tire wear releases zinc. Motor oil leaks, salt used to de-ice roads in winter also contribute to water pollution through urban runoff into a storm drain. Petrochemicals like benzene, are known carcinogens and enter the water from storage tank leaks

28. Water pollutant: leachate • Formed when waste in a landfill mixes with water percolating down from the surface or with groundwater moving through the site. Leachate enters the groundwater under the landfill • Leachate is a mixture including heavy metals (such as lead, cadmium, iron, mercury from batteries and electronics) bacteria, nitrates, sulfates and hazardous chemicals including paints, solvents, pesticides

29. leachate • Leachate pollution can be prevented in a SANITARY LANDFILL, lined with multiple barriers such as impermeable clay and plastic; drainage pipes to collect leachate at he bottom of the liner; plus monitoring wells to test soil and water table for leakages

30. SUPERFUND SITES –hazardous chemical waste that threatens water • Superfund is EPA’s program to prevent, identify, investigate and clean up hazardous waste sites throughout the USA. Groundwater can be pumped and treated, then returned • Known as the CERCLA policy

31. Thermal pollution can occur when shade trees are removed from along waterways or when water is heated as it runs over hot impervious surfaces such as roads and parking lots. Also from warm water discharges from cooling towers or power generating equipment. Dark colored sediments entering through urban or agricultural runoff absorbs more sunlight and creates heat in the water If the temperature exceeds the range of tolerance for aquatic organisms they become stressed and may die as enzymes denature. Also, warm water holds less oxygen so hypoxia may occur Water pollutant: heat (Thermal) pollution

32. Water pollutant: ACID MINE DRAINAGE (AMD) • AMD is a nonpoint source pollutant which can occur during or after mining has ended • Coal and gold mines contain sulfur bearing rocks that when mixed with rainwater and air, creates sulfuric acid. This acid leaches heavy metals such as Fe, Al, Pb, Hg, arsenic and cadmium from the surrounding soil, after which it enters the groundwater or surface waters. • Heavy metals are neurotoxins. They can lead to lower mental abilities. Metals such as Hg can bioaccumulate and biomagnify up the food chain

33. Acid mine drainage increases the acidity, turbidity and conductivity of the stream

34. Decreasing pH causes more metals to leach from soil and enter the stream • pH is a measure of the concentration of H+ ions in the stream. Each whole pH value below 7 is ten times more acidic than the next higher value • The acid is often sulfuric acid formed in coal and metal mines when air, water and sulfur bearing rocks combine. • Even good metals such as Calcium and Magnesium will leach from the soil, depriving plants of these nutrients, lowering photosynthesis.

35. A pH around neutral is optimum for most organisms. Lower than 5 decreases biodiversity

36. Preventing acid mine drainage or at least, mitigating the acidity 1. Adding limestone (carbonate) to contaminated water can increase the pH, neutralizing the acid. 2. Keeping the mine tailings covered with plastic can prevent exposure to water and avoids creating an acid in the first place

37. LEAD and other heavy metals SOURCES: • unlined landfills containing batteries or coal ash; • household chemicals such as paint; • plumbing; • mining refuse/tailings • industrial discharges • IMPACTS: • Can cause cancer • Disrupts learning and memory • Is bioaccumulated and biomagnified up the food chain Lead levels can be lowered by using bacterial bioremediation or chelating with chemical polymers

38. Pollution: PESTICIDES Pesticide pollution come from agricultural and urban areas, especially golf courses and farms. Pesticides drift or enter water through run off They include insecticides (for bugs), herbicides (weeds) and fungicides (mold, spores) and rodenticides (mice) However, 1/4th of all pesticides in the US is for use in homes, gardens, lawns, parks, swimming pools and golf courses.

39. How pesticides become non point pollutants Pesticides may drift on the wind, enter surface or groundwater in runoff. Many chemical pesticides are persistent, meaning they take a long time to decompose. Meanwhile, they are still toxic. Many pesticides kill by interfering with the production of ATP and some by preventing Ach neurotransmitter reuptake

40. Pesticides and herbicides can kill or deform (cause lesions and tumors) fish directly and are linked to cancer and birth defects in humans, if ingested in contaminated fish or shellfish Ecological effects of pesticides extend to entire ecosystems, threatening biodiversity: Pesticides can bioaccumulate and biomagnify in the fatty tissue of fish, affecting the entire food chain and threatening fisheries. Insecticides can also cause a disruption in predator-prey relationships when macro invertebrates are targeted. This results in lower biodiversity in the stream and can threaten top predators such as eagles Water pollutant: Pesticides and Herbicides

41. Bioaccumulation and biomagnification and dispersal • DDT and other organochlorines are broad spectrum and persistent, remaining toxic for a long time • In the environment, they adhere to soil particles, are stored in fatty tissue of plants and animals and magnify up the food chain. Organisms that travel great distances can spread pesticides to far-flung areas. Global trade between countries where pesticide use is still permitted can also spread pesticide coated products

42. CASE STUDY: DDT and Palos Verdes, CA • DDT is present in the Palos Verdes Shelf sediments about 2km offshore largely as a result of wastewater discharges to local sewers from the Montrose Chemical plant in Torrance from 1947 to 1983. • High levels of DDT are found in bottom feeding fish (such as the White croaker) from the area and fish-eating birds such as eagles. The DDT levels do not pose a risk for swimming at the surface.

43. Herbicides like ATRAZINE cause intersexuality in fish • This herbicide, as well as, birth control pills flushed down the toilet or excreted in urine, act as estrogen hormones in fish. • They are termed HAAs or hormonally active agents, also known as ENDOCRINE DISRUPTORS. They are known to feminize fish and frogs

44. Sample question

45. Farms should be placed farther away from surface water bodies to limit the amount of agricultural runoff and drift from aerial spraying that enters streams. Many pesticides dissipate rapidly in soil as microbes consume the pesticide as a source of carbon, breaking down the pesticide before it can enter the water (bioremediation). The natural riparian zone between farmland and stream could act as buffer zone. 3. Reduce the amount of pesticide used, turning to IPM (biological and physical control) instead 4. Promote organic farming which, by definition, does not use pesticides 5. Require training and licensing in the proper use of pesticides Preventing pesticide pollution

46. EXAMPLES OF BIOLOGICAL CONTROL AGENTS • Parasitoid wasps, flies or weevils • Bacterial toxin for caterpillars and some fly larvae, such as that produced by BT (Bacillus thuringiensis) a soil bacterium Biological controls reduce pests via a feeding relationship

47. PRACTICE QUESTION • An APES class was doing a field study of effluent water entering a river through a large drainage pipe from a large building. Which of the following would be a logical conclusion based on their observations? • A) the students observed algae covering a small area of the river a mile away and concluded that the factory was dumping hot water into the river as algae grow profusely in warm water • B) the students detected measurable amounts of coliform bacteria in the river near the pipe and concluded that the building could be a meat packing plant

48. Methylmercury • Natural sources of mercury occur in rocks and from volcanic eruptions. • Human input of mercury is from coal burning, waste incineration and processing metals like gold. Deposition from the atmosphere into surface water occurs during precipitation. • Inorganic mercury enters water where bacteria then turns it into methyl mercury, an organic form that readily passes through cell membranes into plants, animals and biomagnifies up the food chain. • Mercury is a neurotoxin- it damages brain cells, lowering IQ and increased learning disability

49. PCBs • Polychlorinated biphenols are oils used in electric insulation on transformer poles. • Damage by weather caused PCBs to leak into soil, drift on the wind or runoff into surface water • PCB biomagnifies up the food chain and are endocrine disruptors, leading to lower reproductive rates and low population of fish and amphibian species

50. PLASTIC • Storm water runoff from land brings trash, including plastic to the ocean where they break into smaller fragments but do not biodegrade. • Tiny plastic particles are mistaken for food by fish, marine mammals and birds who swallow them and die from blockages in the stomach, starvation or choking or poisoning from chemicals adhered to the plastic