Archive for 'Unit 11-Water Resources & Pollution'
Can someone explain to me the difference between net energy and EROI? I do not understand the difference. I know that they both deal with the amount of energy invested and returned but I do not understand the difference.
Yes, I had to do it. I try to teach environmental science without preaching, but this one topic is hardest for me to avoid. There are probably hundreds of other posts out there on the topic, but I still feel the need to let this out (sorry as it is a bit long with the 3 video clips). If you agree with my arguments, forward the blog link to a parent or friend…
I was born in 1968. I am trying hard to remember (without a Google search) on when I first saw bottled water for sale. Can you? I cannot recall bottled water for sale in college in the late 80s, or when I was in the Army in the early 90s. Must have been the late 90s…at least in my memory.
I found this graph, but I have failed in locating the original source (I think it is at the bottom):
Ok, regardless of my memory, the stuff has become very popular….
So, why my opposition? Well, I don’t drink bottled water for FIVE reasons:
1. Cost. This may be the ultimate rip-off. Let’s say you can buy a 16-ounce bottle for 69 cents…8 of those bottles equals $5.52/gallon (8 x 16 = 128 ounces or 1 gallon). If you drink one a day for 365 days, that’s $252/year on water alone and $2,520 dollars for 10 years! It is more like you paid $1.50, not 69 cents–so double that! Now, last time I checked my tap water costs $1.25/ccf (or about 750 gallons) at the lowest price tier. Not really sure I need to do the math for you, but seems like I’ve got safe water at less than a penny a gallon? Ok, it is 0.16 cents/gallon if you must see the math. Is there really any need to extrapolate my tap water costs out to a year or ten? And, that rate includes what the city charges me for stormwater and sewage treatment facilities–so the price just drinking water is even less.
2. Safety-Water quality. Ok, lots has been published about this over the last 10 years. You check it out for yourself. First, there was the NRDC report in 1999. On the issue of water quality (safety), here is the NRDC answer to the question “is bottled water safer than tap water?:”
“No, not necessarily. NRDC conducted a four-year review of the bottled water industry and the safety standards that govern it, including a comparison of national bottled water rules with national tap water rules, and independent testing of over 1,000 bottles of water. Our conclusion is that there is no assurance that just because water comes out of a bottle it is any cleaner or safer than water from the tap. And in fact, an estimated 25 percent or more of bottled water is really just tap water in a bottle — sometimes further treated, sometimes not.”
So, that was 1999. Has much changed since then? I guess you could start with the EPA, if you trust the government. Here is an answer from the FAQ section of the EPA website on Ground Water & Drinking Water:
Is bottled water safer than tap water?
Bottled water is not necessarily safer than your tap water. EPA sets standards for tap water provided by public water systems; the Food and Drug Administration sets bottled water standards based on EPA’s tap water standards. Bottled water and tap water are both safe to drink if they meet these standards, although people with severely compromised immune systems and children may have special needs. Some bottled water is treated more than tap water, while some is treated less or not treated at all. Bottled water costs much more than tap water on a per gallon basis. Bottled water is valuable in emergency situations (such as floods and earthquakes), and high quality bottled water may be a desirable option for people with weakened immune systems. Consumers who choose to purchase bottled water should carefully read its label to understand what they are buying, whether it is a better taste, or a certain method of treatment. More information on bottled water is available from the International Bottled Water Association (IBWA) (www.bottledwater.org/), which represents most US bottlers.
On top of all that, some bottled water is missing flouride treatment which most cities add to prevent tooth decay from bacteria. While toothpaste does contain flouride, those that drink only bottled water are getting considerably less floride. Note: The benefits of flouride is hotly debated…that’s another story. Regardless, the EPA requires Charlotte-Mecklenburg Utilities to send me a report on my drinking water quality each year. You can access the 2009 report here. Does your favorite bottled water company send you these?
3. Dangers of plastics: I try to live by the precautionary principle on this one. Yes, there are many fears about the dangers of chemicals that may leach out of plastic bottles. Most of this is “frontier science” at the moment–it will probably take years for us to have solid data on health effects. The folks that make the plastic resin (PET) that holds most bottled water say the stuff is safe. A recent study by a professor at the University of Heidelberg documented antimony values (in ppt) hundreds of times higher than that of pristine groundwater. Long term exposure of antimony can cause such as headache, dizzness, depression and in large doses, violent vomiting and death…Others fear the leaching of pthalates into bottled water. Some studies suggest some pthalates act as endocrine disruptors-in particular mimicing the female hormone estrogen.
Even if you don’t buy into the possible health effects on humans, consider the effects of all that plastic on the ecosystem. Oil-based plastics are not biodegradable, but they are photodegradable–that means they will simply break into smaller pieces due to weathering in the sun. So, plastics never go away, they just fragment into smaller pieces. All of this plastic has a tremendous impact on marine ecosystems. Watch this 7 minute TEDTalks segment by Captain Charles Moore for a quick lesson on plastics in the Pacific Ocean:
*To learn more about the Great Pacific Garbage Patch, click here.
4. Infrastructure: In Charlotte, North Carolina, my water bill pays for the water treatment facilities and pipes that carry drinking water (as well as for stormwater drains/pipes and wastewater treatment). My property taxes do not. So, for every dollar I give to bottled water companies, that is a dollar less Charlotte-Mecklenburg Utilities has to treat and transport my tap water. So, as bottled water companies prosper and grow, our public water infrastructure crumbles…The America Society of Civil Engineers (ASCE) recently graded our drinking water infrastructure at “D-.” According to ASCE, we face an $11 BILLION shortfall each year in shoring up this infrastructure. How will we pay for it if more and more dollars go to soft drink companies peddling bottled water?
5. Taste: I honestly cannot tell a difference. But, yes, some folks think bottled water tastes better…I think this short video from the Showtime series Penn and Teller: Bullshit puts the issue to rest:
So, what do you think? Do you buy bottled water? Why? Which of these 5 reasons would you disagree with? If you refuse to drink bottled water, why? If you’ve never taken a stand, do so now! Post a response/comment…
Ok..so I am biased? Here is a rebuttal from the Competitive Enterprise Institute :
Note: “The Competitive Enterprise Institute is a public interest group dedicated to free enterprise and limited government. We believe that the best solutions come from people making their own choices in a free marketplace, rather than government intervention. Since it was founded by Fred L. Smith, Jr. in 1984, CEI has grown to a team of over 40 policy experts and staff.” This boilerplate was taken from the www.cei.org.
Yesterday in class, we learned about how harmful oil pollution can be on the environment. We never really knew the extent oil pollution would have on the environment until the Exxon Valdez oil spill in Prince William Sound occured in 1989.
The Exxon Valdez spill occured in Prince William Sound in 1989 when the Exxon Valdez hit Bligh Reef and spilled 260,000-750,000 barrels of oil. The oil spill is very significant because it is considered to be one of the most devastating human caused environmental disasters and the largest ever oil spill until the Deepwater Herizon that recently occured in 2010. The animals were effected greatly. Birds were not able to fly due to the oil on their feathers. The oil the were on the birds feathers and the otters fur also caused massive decrease in their insulation leading to death caused by freezing. Oil that was consumed by the animals ruined their digestive tracts and other organs that led to serious damage or death as well.
The Exxon Valdez
The Deepwater Herizon is located in the Gulf of Mexico and is a semi-sumersible offshore oil drilling rig that drilled the largest oil well in history at a depth of 35,050ft. In April 2010, an explosion on the rig caused the Deepwater Herizon to sink to the bottom of the ocean while leaving the well open to continue gushing into the ocean. An estimate of 4.9 million barrels of oil was released into the ocean making it the largest offshore oil spill in history. Animals were greatly effected as you can see in the picture below that illustrates the effect the oil spill had on sea turtles and dolphins.
The Effect of the Deepwater Herizon Oil Spill on Sea Turtles and Dolphins
Clean Up Methods:
Once an oil spill occurs, coast guard and other proffessionals much be effective and efficient to reduce the impact of the oil on wildlife and to clean up the oil as quickly as possible. There or physical, chemical, and biological ways help get rid of the oil spills.
- Skimmers: An oil skimmer is a machine that separates a liquid from particles floating on it or from another liquid. A common application is removing oil floating on water.
- Booms: A floating device used to contain oil on a body of water. Once the boom has been inflated, it is towed downwind of the oil slick and formed into a U-shape; under the influence of wind, the oil becomes trapped within the boom. Skimming equipment travels into the boom enclosure and the oil is pumped into containers.
- Dispersants: liquid used to place oil in suspension in the water mass and promote its dispersal, in order to accelerate break down by the natural environment, at sea or in fresh water.
- Bioremediation: the act of treating waste or pollutants by the use of microorganisms (as bacteria) that can break down the undesirable substances
Sources of Petroleum Input in Oceans Each Year on Average (Metric Tons)
- Natural Seeps (600,000)
- Consumptions (480,000)
- Transports (150,000)- Tanker Spills
- Extraction (38,000)- Drilling Rig Blowouts
Oil Pollution Act (1990)- In response to the Exxon Valdez incident, the Oil Pollution Act improved the nation’s ability to prevent and respond to oil spills by establishing provisions. It also provides the money and resources to respond to oil spills. This act requires companies to pay a fine for the damage and for the clean up process as well. Double hulled boats also have to be in use now to lessen the chance of an oil spill occuring.
Exxon Valdez: http://en.wikipedia.org/wiki/Exxon_Valdez_oil_spill
Deepwater Herizon: http://en.wikipedia.org/wiki/Deepwater_Horizon#Explosion_and_oil_spill
Oil Pollution Act: http://www.epa.gov/oem/content/lawsregs/opaover.htm
So I’ll probably have some more questions later, but which aquatic zone has the highest NPP per meter squared? Is it estuaries? Also, I can only find 5 of the 7 in our book. I have Open Ocean, Coral Reefs, Intertidal Zones, Salt Marshes, and Estuaries. Which ones are missing?
So I have 2 questions:
1. I’m confused about question number 4 in section V on the ch. 16 study guide, which is “What factors mask population declines in ocean fisheries and make global catch seem relatively stable?”The wording on this was unclear in the textbook. For one, it said that fishing fleets travel longer distances to reach less-fished portions of the ocean and they fish in deeper waters. But how exactly does fishing deeper and farther away mask population declines?
2. Also, on number 3 in section VI of the ch. 16 study guide, which asks about the issue of China’s fisheries data. I know the fisheries reported that they caught more fish than they actually did to fill a quota, but what is the environmental impact of this inaccurate reporting?
So I have a couple questions overall and then one for Mr. Willard…Overall: What is a solution for thermal pollution? I feel like a medium must be met so that thermal pollution isn’t a problem, but I don’t know how to reach it. What legislation should we know besides the Clean Water Act of 1973? Does anyone have an idea for the essay? What is the salinity of the ocean as a percent salt?
How much should we know about the different aquatic life zones between the two chapters? The study guide said that we would get a review sheet for them but I don’t think I have one.
Sorry for so many questions! Good luck studying!
If swamps can naturally clean waste water, wouldn’t that hurt the ecosystem of the swamp because run-off and feces from waste water will provide nitrogen, and thus start the process of Eutrophication?
Also, isn’t cleaned waste water and drinking water basically the same thing except drinking water has had chlorine added to it?
Today we watched a good bit of the PBS documentary Empty Oceans, Empty Nets. Feel free to click around the movie web site if you want want to explore the issues further. What were the main points?
1. The Problem. Yes, we seem to be overfishing the oceans. In the last 4 years, numerous articles have come out predicting the collapse of most commercial fisheries by 2050. If you have 5 minutes, read this very current article cleverly titled, “Aquacalypse Now: The End of Fish.” This brief public service announcement give some reasons WHY this is happening and what we might do about it.
2. Causes. As mentioned in the PSA above, many of the “industrial” fishing methods used by large vessels or factory ships have the potential to remove fish from our oceans in massive quantities. Check out the animations at this Monterery Bay Aquarium web site of bottom-trawling, longlining, and purse-seine fishing techniques. Additionally, each of these method capture different types of bycatch (bykill). The movie we watched stated that for every pound of shrimp caught in the US fisheries, there may be five pounds of bycatch. Sometimes, it may include endangered animals like sea turtles.
3. Solutions: We saw several solutions throughout the film.
- Since this is a commons issue (oceans fisheries), governments can regulate fisheries by setting quotas in their territorial waters. Anything involving species migrating across oceans and/or beyond those 200 miles offshore has to be addressed by international treaty, but enforcement becomes problematic.
- Governments can establish marine protected areas (MPAs), marine reserves, or marine sanctuaries in their territorial waters. Check this link for the US system of MPAs. These are safe areas for fish to hide and breed as fishing there is usually banned.
- Consumers can create more demand for fish taken from sustainable fisheries. If you care about making a personal impact by your seafood choices then you can download a pocket guide from this web site. There is also an app for mobile phones/ iPhones at that link.
Much of this is covered in your text, but I think it is hard to really appreciate the impact of these commercial scale fishing methods unless you SEE them. You are always welcome to borrow the DVD from me…
Some scientists have estimated that there is 315 billion pounds of plastic floating in the oceans. There is not an island of plastic, as some rumors say, but more of a soup of smaller particles of plastic and ocean.
Out of all the plastic in the ocean, only about 20% originated from ships at sea; the other 80% came from land. Some cities have seperate wastewater and stormwater systems where wastewater travels to a treatment facility and stormwater flows directly into natural bodies of water without any treatment. Other cities have a combined system of wastewater and stormwater, but when a heavy rain comes overflow of the system occurs which allows polluted water to flow into the ocean. No matter the water treatment system polluted stormwater finds its way back into the ocean carrying literally tons of plastics.
Without a doubt, plastic in the ocean causes a mryaid of evironmental issues, such as:
- Plastics are extremely durable, “every bit of plastic that has been made, except for the small amount that has been incinerated still exists today.” Plastics are so durable because they don’t biodegrade, but rather photodegrade. That is, plastic just breaks down into smaller and smaller peices. Bottom-feeders can mistake these small plastic pieces as zooplankton, and seabirds can mistake bottle caps as food. A video of drowing the ocean in plastic.
- Plastic serves as a cruise for organisms to sail the ocean currents causing biotic mixing–this is an invasive species vector. Organisms, like barnacles, live and grow on the floating plastic debris and drift on the ocean currents, spreading North American aquatic species to the coast of Japan as an example.
- Plastic can also act as little poison pills. Because plastic is hydrophobic and lipophilic (wont dissolve in water but will take up fats and grease), it can absorb oils and accumulate toxins, and some fish have been found to eat small plastic pieces which speeds up bioaccumulation in organisms.
On any given day, each one of goes to the bathroom at least a few times, and most likely without any thoughts of where our waste is going or what it will become. After venturing to the Mallard Creek Wastewater Treatment Facility; however, what happens when we flush, at least for me, is a much more prevalent thought. When we got to the treatment facility and stepped off of the bus, I think almost every single one of us had something to say about the smell, but little did we know that the worst was still to come. My group began our tour in the office building looking at an aerial view of the entire facility.
As you can see, it’s pretty big and pretty spread out. It is designed this way so that each process is separate. One important feature to note that may not be apparent from the above image is that the facility is located on a long, gradual hill. Rather than pumping the water between processes, the water is pumped only one time from its initial incoming from the sewage to the top of the hill. For the remaining processes, the water flows down hill so that less energy is used and the process is more efficient in general.
The treatment process begins when we flush the toilet, and our sewage waste travels through a series of piping systems to one of Charlotte’s multiple wastewater treatment plants. As the wastewater reaches the end of the piping system, it flows into somewhat of a temporary holding tank with screen systems attached. This system is comprised of bar screens, which reach into the water and anything solid such as toilet paper, condoms, tampons, dead goldfish, etc. get trapped on the screens, which pull these objects out of the water and dispose of them in a dumpster along with any “grit” like undigested corn, gum, etc.–all of which most likely ends up in a landfill. Next, a cyclone type machine spins the still heavy water down a tube and it is moved into a system of clarifiers.
In each cone-shaped clarifier, the wastewater’s velocity is slowed and the solid components of the water, the “sludge,” settle to the bottom. After the clarifier allows the solids to settle to the bottom and the oils settle on top, giant rotating weirs move circularly around each clarifier, scraping the bottom where the solids have accumulated and the surface of the water, and the resulting somewhat cleaned water moves on to the next step. The removed sludge is transported to an anaerobic digester which heats and spins the wet mixture and is then dried for fertilizer for crop land or a landfill.
The heart of the facility is found in the aeration tank. The aeration process is a biological process that takes 6-8 hours as organisms are used to break down the excessive ammonia and nitrite found in the water. As a product of these aerobic organisms at work, the water in the tank is coated with a thick layer of light, brown bubbling foam. (We were all surprised to learn that this foam was not floating poop.) The aeration tank can be thought of as a “zoo of microorganisms,” and the water is oxygenated so that the aerobic microorganisms can effectively break down the bacteria and solids in the water. From the aeration tank, the water is moved on to more clarifiers and as the solid, heavy water once again settles to the bottom, it is scraped and drained out and back into the aeration tank to feed microorganisms. At this point, the water is (believe it or not) 99.9% cleaned.
(fun fact: As Emily and I reflected upon the horrible idea of jumping into this foamy tank, our tour guide noted that legend has it that because of the way the tank works with suction and because SO much oxygen is produced, there is no surface tension to this water and so if you jumped it, you would immediately sink 20 feet to the bottom and basically drown in poop. We decided this would be the worst possible way to die.)
After the water moves from clarifier > aeration tank > more clarifiers, the water must be filtered one more time before it can be disinfected and released back into the environment. The water is moved from the last clarifiers to another large tank where mixers churn the water so that it does not become septic. In these tanks, traveling bridge filters use dividers with anthracite coal and sand to filter the water. The traveling bridge works by forcing the water through the sand so that the particles collect in the sand and charcoal leaving the water cleaner and without solids.
Next, the water is moved from the filtering system to the disinfection stage. Originally, chlorine was used to disinfect the water; however, the problem with the chlorine treatment was that even though it killed every single microorganism in the water, as the water was then released into the environment, the chlorine continued to kill everything in its path which proved destructive to the stream or creeks the water was released into. Recently, more and more wastewater facilities have begun to use UV rays to disinfect the water. This process works by using the damaging properties of UV rays to basically microwave the microorganisms in the water, scrambling their DNA so that they can’t reproduce. This means that when these organisms reach the environment once again they will decrease and die out in population.
The result of this entire process is a relatively clean water that is suitable and safe for the environment, but not for direct contact with people. After all steps have been completed, sewage > clarifier > aeration > more clarifiers > filters > disinfection, the water is either released into a nearby water source, in this case Mallard Creek, or it is put in some sort of a holding tank. At the facility we visited, some of the water was mixed with hyperchloride which is not safe water for humans but can be used to water golf courses, for example, for free. The remaining solid waste from this entire process is heated for about 45 days, the resulting products being a small amount of water, gases, etc. which are spun into a black material which is used for fertilizers which can’t be used to grow crops but instead are used for growing grass which farmers can turn over to increase an areas fertility, etc. We all wondered what happened when there was a big rain and all of the rainwater filled up the open clarifiers, aeration tank, etc. The facility is built to contain about 20 million gallons of water, so rain is not a problem. There is also a rain retention basin in the middle of the facility as well which can hold up to 50 million gallons of water and stores rain water and excess raw sewage.
The last part of our day consisted of testing the water in Dragonfly pond at Reedy Creek Nature Preserve for turbidity, pH, temperature, phosphate, nitrate, and dissolved oxygen/%DO saturation. (We assumed coliform bacteria to be present)
After conducting these physical/chemical tests, we moved to the lab where we focused on bioindex which is basically how clean a body of water, such as a stream, is based on what organisms it can support. All organisms have a different toleration for pollution, an example of an animal that can live in very clean water being a mayfly or a stonefly, while the dirtiest waters are home to organisms like leeches. We used a Dichotomus Key to look at and identify several insects, the process necessary for determining the bioindex of any body of water.
Images source: Derrick Willard