today we're talking uh water pollution and the next several chapters as I mentioned before on water pollution air pollution global warming and ozone are really important chapters to really read and understand for the AP exam because keep in mind that almost a third of AP exam questions multiple choice questions come from pollution alone so it's really important you have a good handle on all the terms in this chapter and they're not hard it's just a lot to remember the uh the opening story this picture here is about the Chesapeake Bay and the Chesapeake Bay is uh between Virginia and Delaware up in the Northeast and there are lots of waterways that will contribute to the Bay it's the largest Estuary in the US and has a lot of environmental issues and a lot of it comes from if not a huge majority come from um human activities and it's from uh animal feeding Lots so their manure gets um either dumped purposely or leaks into the river waterways sediment pollution is an issue um Pharmaceuticals getting in there even birth control um had been getting into the water which was causing sever severe issues with some organisms that turned out to be hermaphrodites so both male and female parts due to the human uh dumping uh oh there we go so what is water pollution contamination of streams rivers lakes oceans or groundwater with substances produced through human activities and that negatively ffect organisms a good uh well an important point to remember are the two types of sources from which water pollution comes from they are always asked on the AP exam so know these two terms Point sources and non-point sources Point sources mean that this particular polluter I can actually point to and say yes that is it that is what is causing the pollution so it could be a particular Factor that empties um out into the water it could be um a specific animal manure area um so I'll go back to that in a second and a non-point Source means that it's a very diffuse or large area that you could it's very hard to point to so or it could be a series of places that are contributing the pollution so you can't really narrow it down or Target who it is so that could be an entire farming region it could be an entire region of factories that you can't tell where the source exactly is um but you know a roundabout where it's coming from the problem with those is that because they're hard to Target it's hard for the EPA to say you're responsible and you need to clean it up so a good hint is that a point source is singular if they were asking you a multiple choice question and they said which one of these is a point source a pollutant if you see one that is singular it's more than likely the point source if it's multiple like animal lagoons or farming areas so plural those are more likely to be non-point sources so there you go a particular pipe that is releasing pollutants into a body of fresh water is a point source excuse me it doesn't have to be fresh water it can be ocean water too and in non-point Source you can see this large farming area um where it would be hard to point exactly to the source so what are the different types of water pollutants human and animal waste inorganic substances organic compounds and non-chemical pollutants here is a a river in China that are greenish black from pollution from factories and so they could be so polluted that uh you could light it on fire just like in the civil action so that's pretty gross human Wastewater is obviously a problem um mostly in developing countries but in developed countries uh human Wastewater is also released into fresh bodies and the EPA does give them permission to do so well I shouldn't say the EPA but factories are um able to do so and I'll get to that in a moment so water produced by human activities such as human sewage from toilets gray water from bathing and washing clothes or dishes is considered waste water in in developing countries a lot of times people will wash their clothes take a bath and go to the bathroom all in the same area in the same body of water so you can imagine how nasty and contaminated that water is and how dangerous it could be to consume it or to even really be near it why scientists are concerned about Wastewater are the oxygen demanding waste like bacteria when you have decomposition in water uh bacteria in decomposition consume a lot of oxygen and so that creates an oxygen sag curve and when you have um not a whole lot of oxygen well then obviously uh organisms are not going to be able to respire and they will die as the water becomes hypoxic which means very low oxygen or anoxic which means without nutrients are released from Wastewater decomposition so such as nitrogen and phosphorus which are the two that we've learned about before um which makes the water more fertile causing nutrification we've talked about nutrification and that's more of over fertilization oh I guess that'll be on the next slide so when you look at dissolved oxygen content in parts per million you want it between eight and nine when you're looking at water quality so see this is why I really wanted to um get dissolved oxygen uh measurements in your ecob bottle Labs because it's important to see if it's a good quality water and that this ecosystem is self-sustaining and being efficient at um removing waste but also not depleting oxygen so if you see that you know if a question on the AP exam said hey the the the do is at three is this good water quality or bad you know that it's going to be bad biolog uh excuse me biochemical oxygen demand is called the bod and that's how much oxygen a an amount of water needs to use over a period of time at a specific temperature can you hear me sorry I thought my microphone was getting weird okay so if you have a low bod that says that the water is less polluted and higher bod values indicate that it's more polluted when bodies of water have high oxygen demand because of microbial decomposition the amount of o2 for other organisms is low so take a look at this oxygen sag curve this picture is not in your textbook as far as I know this was in an old textbook um but questions have appeared on the AP exam about oxygen sag curves so if you notice in your clean Zone the bod is low so that means that it's nice clean generally clean water and the dissolved oxygen as at around eight okay now look at what's happened here now I've got a point source of effluent or just nasty stuff that's been deposited into a water body and so as the um effluent or polluted water enters the water source um the bacteria are going to try to consume it and break it down which leads to here that that needs to more oxygen demand but the oxygen is getting consumed by that bacteria so after a while when the decomposition is starting to finish and the pollution is starting to diffuse then it'll start to recover and then you have clean water again urif is the abundance of fertility so again overfertilization and we've talked about this several times urif or the adding of of nutrients such as nitrogen and phosphor phosphorus like nitrates and phosphates which you'll get from fertilizers pesticides um and other chemicals that can cause the rapid growth of algae which eventually dies and then so the micro need more oxygen they consume the oxygen and then it causes the oxygen levels to decrease for the other organisms and remember too in chapter nine we talked about a utopic lake which means it was an older Lake that's been around for a while the water is cloudy it's dirty it's got a lot of algae and decomposition in the water common diseases that come from Human Wastewater include those there C is a big one and a lot of these um of course are in the developing countries notice these that half of diarrheal and malaria death could be prevented with safe drinking water and proper sanitation and hygiene so that means not taking a poop in the river 42% of the world's population lacks access to proper sanitation and over half of them live in the two most populous countries in the world China and India if scientists want to check out if a body of water has disease-causing pathogens they often look for feal coliform bacteria such as eoli because eoli will lives in our intestines and if we poop in the water or if just human waste or animal waste gets into the water system and um shows up in the Test eoli shows up in a water quality test we know that human or animal waste is in the water so notice there that a count of zero cifor bacteria is acceptable for drinking water but it could be quite high at a beach or a river meaning you could still technically swim in it you just wouldn't want to consume it um and due to ecoli um infestations if you will in water bodies sometimes the government has shut down a body of water from being being able to be swam in due to high levels of human waste well how do you treat human and animal Wastewater there are two ways one is a septic system and if you live out in the country or know someone who does they probably do have a septic system I know my family does uh who live in the country in potit and so here's a diagram you see of a septic system you have a container that will receive the Wastewater from the house and what at least hap happens in my family's house is that you can't put toilet paper or anything except the actual waste in um the the toilets because it will go into the um septic tank and start to uh clog it up in the tank or in the Wastewater container anything that floats to the top and you know what I'm talking about is called scum and anything that sinks and is more dense than water is called sludge and then that middle layer which is just regular water is called septage the septage contains bacteria but it also contains um pathogenic organisms so disease potential disease causing organisms nitrogen and phosphorus through gravity uh the water will flow through pipes in the lawn which is called the leech field the good thing about um septic systems is that no electricity is used in these things they just rely on the gravity um the pipes contain small little holes so that the water slowly seeps out and will spread across the leech field so what happens um is that that septage or the the water is filtered out and filtered through the soil the harmful pathogens settle out become part of the sludge and then can be decomposed by uh microorganisms and you might have seen in commercials that a lot of times they have that ridex and that's basically adding bacteria to eat away at the sludge because if you don't you have to have it pumped out every 5 to 10 years if you don't it gets backed up and then you have a poop smell coming from your lawn and that can be really expensive to fix for people in metropolitan areas such as us living in San Antonio we depend on sewage treatment plants and there are um two types of main treatments that they will go through the first is the primary treatment and that's when all the solids will settle and dry out or be dried and that's the sludge water water is removed and that will reduce the volume of the whole thing and bacteria is added just like the ridex I talked about in order to try and consume some of that waste um the goal is for for primary treatment is to get the solid waste material out um when the sludge is settled out of the Wastewater and been treated then the remaining water goes through secondary and the goal for this is to use bacteria to break down 85 to 90% of the organic matter in the water and convert it to carbon dioxide and nitrogen and phosphorus so basically what will happen is the water is air rated or air oxygen is pumped into the water to promote bacteria growth so that it will decompose the organic matter the last step is for it to be disinfected with either chlorine ozone or UV light this then that water is released into a nearby nearby river or lake the problem is is that with secondary treatment there's still nitrogen and phosphorus in the water and we've already established that nitrogen and phosphorus are good nutrients for algae growth and so when they are pumping this treated Wastewater it still has all this nutrients that can lead to urif foration um and so companies are trying to get rid of the nitrogen phosphorus through tertiary treatment and that is either adding more chemicals to try to get rid of them or adding different bacteria that are genetically modified or natural that will consume more nitrogen and phosphorus so denitrifying bacteria that we've seen before in the nitrogen cycle and phosphorus organisms that will actually absorb and hold on to phosphorus or also used so that's tertiary so we can get as much of the nutrients out of the um Wastewater so I will let you you can pause so that you can look at this you do need to know these I will tell you that one of the AP frq prompts um from a few years ago asked the students to very um descriptively State what happens through primary and secondary treatment probably since they asked that just a few years ago or several years ago they wouldn't ask that exact question but you need to know what goes on at both primary and secondary treatment of Wastewater um manure lagoons this is a manure Lagoon here and so that is just animal waste um that is being dumped into a giant Pond that has been lyed with rubber to try to get it from seeping into the groundwater um and again they add bacteria to try to break down the the organic waste in it and once it's been dried out um they turn it into pellets for gardening um or fertilizers so you could imagine that a lot of times um pollution is happening because there are breaks in the the liner and that could get into the groundwater let me go back uh for a second to the human Wastewater part these treatment plants are very critical to our health because they take away a lot of the harmful organic matter and pathogens which is why we don't worry about waterborne illnesses as much as developing countries do who you know will go to the bathroom and wash their hands and wash their clothes and bathe um in the same body of water however a lot of times raw sewage which is just urine and poop filled water could actually be directly pumped into rivers and lakes and what happens is that when there are uh periods of really heavy rain older sewage treatment plants get uh storm water from those rains and so then it overflows so when they they have an overflow to the the can't handle that capacity the uh the treatment plant is allowed to bypass the normal protocols and actually pump water directly into a nearby lake or um stream and so what happens is that you could release a billion gallons of raw sewage um into surrounding body uh water bodies and this has happened in Indianapolis as they've seen and as well as as the Chesapeake Bay that's one of the reason why it was so polluted so it does happen in developed countries all right so we're past the human and animal Wastewater and now we talk about other substances such as heavy metals we've talked about heavy metals before as um a as impairments to human health lead is one that will damage the nervous system so that's why we have unleaded gasoline paint no longer contains lead as that was um giving children mental retardation um but lead can still contaminate water because if water is going through old pipes those pipes still contain lead and um and so those little bits of lead can still get into the water arsenic is a naturally occurring um heavy metal so it's found in the Earth's crust it's found when um you mine in mining operations and but it readily dissolves in groundwater and so um mining like for coal can release arsenic into the water and that is associated with uh cancer so there's a map that I'm going to show you right there that will uh show you the highest concentrations of arsenic are generally found in the midwest in the West um and that's when they're found in wellwater and sometimes these illnesses can take up to 10 years or more uh after exposure to develop so sometimes it's years after you've even been exposed before you notice that there's a problem um and so the EPA has lowered the the limit to I'm sorry where was I oh has has lowered the safe limit so they put limits on how much is actually acceptable and we talked about that briefly when we talked about the risk chapter and the toxicity that how much risk are you um willing to accept in your water and arsenic is one of those things where they you know it was set at some level of 50 and then they lowered it to 10 then they lowered it to five and then it had to be back up to 10 um because of a lot of pressure so there could still potentially be arsenic in your groundwater um but a lot of times it is if you're going to be near mining operations so if you look once again San Antonio not such a bad area to live in because there aren't so many mines here Mercury is a naturally occurring heavy metal um most of the time we'll get it as it falls falls from the sky from burning fossil fuels like coal remember coal is the dirtiest fossil fuel to burn and uh mercury levels have increased in the oceans because of the Mercury falling down um from the smoke stacks of coal mines excuse me um electric uh power plants from burning coal you can also have mercury from burning garbage Medical Dental Supplies from all the metals in there and this is a big one because it will buy accumulate in aquatic food chains and we've seen that um as you don't want to eat too much large predatory fish like tuna because it bioaccumulates in the larger fish and mercury has been known to cause nervous system damage the other one that um that will bio accumulate is DDT that that has been well documented and it was because that it bioaccumulated in organisms and made the shells of Birds Go soft so that meant the fewer birds were being hatched which means populations crushed um and it was uh the book Silent Spring that uh started environmentalism which banned which led to the Banning of DDT so do make sure that you read page three 392 about pesticides there's a little too much um in the the reading to put on the slideshow um acids are also released into the atmosphere from the burning of fossil fuels so you have sulfur dioxide nitrous dioxide that gets released from burning coal um when they get released into the air they're converted to sulfuric acid sulfuric acid does burn skin in concentrated amounts so if you have wet this is important here wet acid dep position is in the form of acid rain so acid rain does have sulfuric acid in it dry acid depos uh deposition occurs when the gases or uh solid particles attach to soils plants and water and what happens is that that will reduce the pH because remember the lower the ph the more acidic so the more acidic the water um the more lethal it could be to some species as that takes them out of their um Zone they're um oh I forgot the word the the zone that they prefer to live in um we'll also get into the acid deposition a lot more in air pollution but just know um the difference between wet acid deposition and dry acid deposition Mercury production I'm not really sure why that's that important here so um I'm G to pause a oh yeah so going back to to to Mercury um a lot of it is coming from um most of it is coming from the burning of fossil fuels which is about 2third of that um and the notice where a lot of it is coming from Mercury production is coming um a majority of it from um Asia um part of the problem and and like I said before when you don't want to eat too much predatory fish like tuna but it's also shellfish or sushi you need to be careful that you don't eat too much sush Sushi um at one time especially if it's tuna sushi and I'm not a sushi eater so I don't know what's really a lot but um if you look in your textbook it said that in 2008 a reporter for the New York Times purchased tuna sushi from 20 locations in New York City and after analysis found that at most restaurants a diet of just six pieces per week would exceed the EPA standard for human consumption of mercury so that could mean it's affecting you and particularly if you are a woman that would be a teratogen meaning it's causing harm to the fetus so one of the the steps that they're trying to do to get rid of mercury is to um uh try and reduce the emissions for um Mercury or other pollutants in the scrubbers which are uh in smoke stacks of power plants to try to to reduce those uh solid particles from emitting um here this is an underground mine that was abandoned and so as they were mining away the land started to subside or to sink and as you have the ground water that runs along the top you see that it's turned like this Rusty color and that is coming from the pyite pyite is iron uh F2 so iron sulfide and when it mixes with water it will break down into iron and hydrogen and um Iron and hydrogen will make the water more acidic so that's pretty nasty so mining um has a great deal of influence on pollution this is showing you um how synthetic or human-made organisms are organisms U products are making their way into water systems and if you see there steroids are making their way into water systems a lot of that is when you throw away things down the toilet and that's one reason why you should never deposit old medicines into the the water system um you shouldn't uh throw away birth controls pills that's a big one too the reproductive hormones are coming from birth control pills that are being sometimes they're being thrown away properly and then with um but maybe the the liner in the landfill leaks um you never really know exactly what's happening to it once you throw it away but um uh hormonal drugs antibiotics non-prescription drugs like Tylenol ibuprofen all of this is getting into the waterways and not only contaminating it for human consumption but contaminating it for other organisms industrial compounds are another type of water pollutant um and Industrial compounds are those chemicals that are used in manufacturing and unfortunately many were dumped into bodies of water directly and purposely uh for a way to dispose of of them which is just insane um an example of uh industrial compounds being uh disposed of was in Ohio um on the Koga River and industries had dumped um their waste products for over a hundred years and had killed all the animal life that was in the river and eventually caught fire several times um in the 60s and so it's much cleaner now because of legislation but just imagine how incredibly polluted that water was back then pcbs are polychlorinated biphenols and those are used in Plastics and although it's no longer manufactured it has um a long persistence so it stays in the area um for years and years and and can be carcinogenic or cancer causing when it's ingested um a big case of it was when GE General Electric had uh dumped Millions a m over a million pounds of pcbs into the Hudson River and the EPA demanded that they dredge it uh to dig it up um which they fought because they said it was going to stir up the sediments and then increase the the pcbs in the water again but the EPA won and so they did have to to dredge the river to try and dig it up uh pbdes are polybrominated diphenol ethers and those are used as flame retardants so they're put in clothes they're put in building materials or Furniture to obviously make them less flammable um but somehow they were getting into waterways because they were uh showing uh pbdes in fish in Birds and in breast milk and that can lead to brain damage so many types of those compounds have been Bann oil pollution uh we're a little bit more familiar with and what this graphic is showing you is where these sources of oil come from in the ocean so in a is North American Marine Waters and notice that 62% is a natural seep so what scientists have discovered is that um oil oil can naturally sleep from the bottom of the ocean and we have to consider that when we also have spills or leaks from industry because there's that combined um human and natural um release of oil so from consumption of products from the transportation of the petroleum itself from actually extracting petroleum from the ocean floor um will cause cause leaks and Spills and then the on the right is the worldwide annually 322,000 pounds of oil leaks in North American Waters those are from the oil platforms usually in the Gulf um but worldwide it's actually worse and can go from the same amount 322,000 lbs to over a million pounds of oil in other parts of the world where the uh rules are less stringent in 2010 you're probably more familiar with the BP uh explosion um off the deep water Horizon platform in the Gulf of Mexico and there uh between the time that the explosion in April until they actually finally sealed it in August it released about 206 million gallons of oil into the Gulf and so you can imagine how much uh it contaminated beaches the wildlife um the freshwater estuaries along the coasts and so and did I say the animal life and of course the animal life um one real big famous one when I was a kid was the Exxon Valdes that happened in 1989 in fact it was the 25th anniversary this week um in March um in which it spilled 11 million gallons of oil and killed hundreds of thousands of seabirds and Otter and seals and even killer whales so they've been cleaning it up now for 25 years and it's still ongoing and they estimate it's going to take uh about a hundred years for it to fully break down and that's one of the things we have to think about when oil is naturally seeping into the uh water from the ocean itself from the ocean floor that um over time it will finally disperse and be remediated but then you add in human induced oil pollution and it's just going to take a lot longer so there you see um this is from The xon vald Spill so how do you clean up oil pollution well there's a couple of ways um and they started experimenting a lot after the Exxon Valdes because of how much was released although it was only 11 million and BP was 206 million but um they tried to contain it using booms which are these um plastic containers that just float on the surface because keep in mind oil is does not mix with water so oil will float on top of water but it also makes this really thick layer so you have to make sure that those containment booms um will be I guess thick enough to try to block the oil from spreading so once they're able to contain that in an area they will try and suck it up with vacuums um other wise they've tried to apply chemicals that try to make it disperse before it hits the shoreline and then cause damage to the um ecosystems so although that could be effective think of it kind of like spreading the bacteria to break down Solid Waste um it's still a chemical and so the chemical could be toxic to the wildlife and then they also um have genetically engineered bacteria that would cons consume oil from natural seeps so they decided to get those to try to uh eat up human spilled oil other water pollutants include uh solid waste so again don't pollute don't be throwing away um any kind of trash into the water obviously things will uh contaminate the water sediment pollution is not one that people normally think about but the Chesapeake Bay up in Virginia does have that issue of sediment pollution so when you start to build and develop cities especially along coastlines you are taking away trees which take away Roots which anchor some of that soil and so the soil will easily wash away and then they go into the water bodies that move and so they could empty out and make um the Deltas very clogged with sediment just like the Mississippi is is right now um they become Brown they become ugly and that reduces productivity of plants thermal pollution is also another one when um when they empty out heated water from industry up out into open bodies of water fresh or ocean water so because that's out of that range of tolerance oh tolerance was the word I was looking for earlier um because the heated water takes those organisms out of their range of tolerance for temperature many will die and then noise pollution is also considered a pollutant in water because of ships interf interfering with whale communication um this is a river in Indonesia that is just loaded with trash I mean that's just disgusting can you imagine this is um the Santa Ana River in California and so it's going out into the Pacific so you can see all that sediment that has been um emptied out and it forms this Delta that's a lot of sediment that should not be there and it's mostly a result of all the development going on that causes all that loose soil to be washed away um this is in Iceland and a lot of people in Iceland will um go in the in the bodies of water that are heated by geothermal energy so energy from the the Earth and so they have this water here that is by a nuclear reactor and as I mentioned before when it comes to power plants whether it's coal or especially nuclear they have to cool down the water that they have used to heat up because remember they turn they they heat up the water to to cause steam to turn the turbines to turn the generators to generate electricity well that water has to be cooled down so when they use um those cooling tanks and after it's um cooled they return it to Natural bodies of water but it's still pretty hot water laws these are important the Clean Water Act of 1972 uh was established to protect uh fish shellfish and Wildlife and keep in mind that it does not include the protection of groundwater which is what we get our drinking water from so it really focused mostly on the chemical properties of the surface waters the Safe Drinking Water Act then was established later to set the standards for Safe Drinking Water and that's where they put those acceptable um contaminant levels for substances in water and groundwater for us to drink and so here you can see some micro microorganisms this is for drinking water so this is um and and notice that it's in parts per billion not parts per million so no fecal CA form bacteria is acceptable for drinking water because then you would be drinking human poop um but notice that arsenic is is acceptable some parts of mercury some parts of benzene atrazine um are allowed and considered tolerated in drinking water and this is also how um waterways have been impaired so just take a look at those charts developing countries are still in the process of industrializing so they have less restrictive environmental laws have less money to fund water quality improvements like waste treatment plants so what's really important in the developing countries is to try to get them some clean pable water and some facilities to treat um especially human Wastewater and to try to get them from not bathing and washing and pooping in their waterways but as would be expected as a country becomes more um industrialized it becomes more affluent regulations will improve sanitation improves hygiene improves so water quality will improve all right this is the end of chapter 14 thanks just let me know if you have any questions