Mar 29 2012
I missed the video that you guys watched in class. To what extent do I have to understand stormwater?
Mar 29 2012
I missed the video that you guys watched in class. To what extent do I have to understand stormwater?
Mar 27 2012
*Note: Since I forgot to ask for a scribe, this is a guest post by EvanR from last year from a similar lesson. A nice, concise post with links to more info. It is based on this 12 minute video about one of the first voyages to document the Great Pacific Garbage Patch.
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:
*Here is another video of the synthetic ocean (*this is the 7 min TEDTalk from the Bottled Water Post).
Mar 26 2012
Today we visited one of Charlotte’s waste water treatment plants (Mallard Creek), and did some water testing at Reedy Creek Nature Preserve!
The waste water treatment plant was all about going to “away”. When you flush things down the toilet or pour something down the drain, you are sending things away. Well here at the treatment plant, there is no away. Everything has to be sorted and dealt with (from diamond rings to latex condoms–lots of latex condoms.)
First the inflow comes to the bar screens where large pieces of debris and various other things (condoms, tampons, toilet paper, plastics) are raked out. The plant screens out the solid objects or grit, after allowing the water to settle in the settling tank
Then the water, still a murky brown, goes to a primary clarifier. Here the oils and greases float to the top, and the solids condense at the bottom as sludge. It’s sludge, not poop.
Next the water goes to the aeration basin. Here the plant has a “farm” of microbes and bacteria that consume the organic matter. The basin is constantly aerated to supply the microbes with oxygen, and sometimes the nearby Cheerwine plant with give the plant their waste sugar water to feed the microbes. On days like that, you better believe that denitrification is working.
The plant CAN deal with up to 12 MGD (millions of gallons a day), but they average around 8.5.
Fun Fact: If you fell in the aeration basin, you would sink to the bottom and drown. Do you know why? ….
because the DO (dissolved oxygen) is so high that the water is too light for our dense bodies.
Next, the water goes through some secondary clarifiers (which look identical to the first), and finally, to be filtered and disinfected before reentering the stream. The disinfecting process is done with giant UV lamps that sanitize the water; the lamps destroy any pathogen’s/bacteria’s/organism’s genes beyond reproductive potential, so it’s safe! (Safe for the stream…not drinking.)
Meanwhile, the sludge goes to an anaerobic digestor, where the methane is burned off, and the remaining solid (known as cake) is sent to animal farms for crop fertilizer.
After the treatment plant, we went to Reedy Creek and tested the waters in Dragonfly Pond. The pond did not have particularly high numbers in general (a fairly low DO and a fairly low nitrate/phosphate level). We took tests on pH, temperature, and fecal coliform presence. Fecal coliform is bacterium that comes from feces (poop), and it’s important in water sanitation. Many people were walking their dogs around the pond, so it’s no surprise that coliforms were present; furthermore, the phosphate/nitrate level makes sense considering there is no farm or lawns to runoff their fertilizers into the pond. Lastly, without a fountain to mix oxygen into the pond, it was free standing, so the low DO makes sense as well. It is important to remember that our sample was taken at the edge of pond, where the temperature is warmer; thus the do is lower. Had we taken a sample fifteen feet underwater in the center of the pond, we would probably have a much higher sample.
After the fun “hands-on-stuff”, we had to trek back indoors and listen to a park naturalist. She explained the values of Bio-indexing. Basically, the organisms living in a body of water indicate the health of that water. If there are lots of organisms that are very sensitive that pollutants, then the water must be relatively untouched (otherwise those organisms wouldn’t survive). On the other hand, if a body of water only contains organisms that are very resistant to toxins, then you have a problem on your hands. Next, we looked at pictures/descriptions of aquatic bugs.
Mar 25 2012
On Thursday and Friday of last week, we began to move away from the problems of water shortage and towards the problems of water surplus. We began with Flooding- a natural phenomena that occurs when an overflow of water submerges land. Precipitation is the main catalyst for flooding, and humans have tried to control how much of an impact it has through various means of flood prevention.
Main locations of flooding-
1) Floodplain- an area of flat or nearly flat land adjacent to a stream or river that stretches from the banks of the channel to the surrounding areas. These areas are subject to natural flooding when rivers overflow their banks.
2) Reservoir- artificial lakes that are created by dams to store water. They are often used to control water flow downstream, irrigation, and provide recreation. While the dams that contain them are engineered heavily to try and minimize failures, they have still failed in the past and created catastrophic walls of floodwater that destroy property downstream.
3) Dam- a barrier that impounds water or underground streams. They are created to retain water and control its flow, while levees or floodgates attempt to prevent flow into a specific area. They can use the retained water to generate hydroelectricity while still controlling its speed and direction. When dams fail, the reservoir of water that was previously contained is now unrestricted and can cause massive destruction of civilian property downstream. In 1975, the failure of the Banqiao Dam in China killed an estimated 171,000 people!
A very famous and large dam- The Hoover Dam
4) Levee- a naturally occurring ridge or artificially constructed wall which regulates water levels. They are often used to prevent the destruction of civilian property in case of high river levels, and the largest such system in the world is along our Mississippi river. When levees are overwhelmed and fail, the water spills over and floods the adjacent land which it was originally supposed to be protecting, destroying property, as seen many times during Hurricane Katrina in 2005. Sometimes the levees are intentionally breached to protect areas further downstream or to give land back to nature.
This is how a levee/dike works-
5) Floodwall- a vertical wall created to protect property from rising river levels during a seasonal or unusual case of high water levels. They are mainly used where space is scarce and levees or dams aren’t viable options for containing the same waters.
Ranching, the practice of allowing livestock are allowed to graze in fields, accelerates soil erosion. After the grass is gone, winds remove the remaining fragile topsoil, rapid water runoff causes loss of silt and other erosion, and downstream this all combines to create flooding.
Natural Solutions to Flooding
1) Conserving or Reestablishing Wetlands
2) Improving water retention through the floodplains along rivers
3) Encouraging natural systems such as forests and wetlands along rivers
Not only does this decrease the strain on our infrastructure to maintain artificial control mechanisms, but it also would improve water and air quality, protect productive farmland, and allow people to live without fear of the failure of human-made systems.
Mar 23 2012
Monday in class, we began to discuss water shortages and solutions. We came up with four causes of water shortages:
1. Dry Climate – Examples would be found in different regions, such as the Desert, Tundra, or Chaparral. These areas tend to have drier climates, which also makes them have less of a water supply in these areas.
2. Drought - This is simply the lack of precipitation.
3. Desiccation – (dry soil) For example this can happen where a lot of agriculture takes place. Also when plants are taken out of an area, which ultimately results in less transpiration causing a water shortage.
4. Demand – This can relate to water stress. For example, the more demand we place something like a well, there might be a chance that you can run the well dry.
After we discussed the water shortages, the following day we went over four ways to fix water shortages. Each one had there own environmental impacts which we mainly focused on.
1. Dams – Dams have the potential to capture sediment on one side of the dam, not allowing it to continue down the stream. This means that less of the nutrients are going down streams to other fish. Also, another common issue with dams is that they block migratory fish, such as salmon. To prevent this, sometimes a fish ladder is added in, which always the migratory fish to go up a ladder to bypass the dam.
2. Water Transfer – This includes aqueducts, ditches, and canals. This can result in habitat destruction and loss of biodiversity. An example we discussed in class was the Aral Sea, which all started by an 800 mile water transfer project. The sea has now loss much of the water it used to hold.
3. Groundwater Withdrawal – There seems to be multiple benefits from this, like year round use, no evaporation loss because the water is underground, and it can often be less expensive. But there are still negative environmental impacts from this process. Some of these might be lowering of the water table, which can cost a lot of money if you have to dig your well deeper to reach the lowered water table. Also, depletion of the groundwater from over drafting, and subsidence can occur, which would lead to sinkholes. Near the coast a different set of problems occur, like saltwater intrusion, which gives the water a sulfur taste you might have experienced near the beach. And lastly, the groundwater could be contaminated by chemicals leaching into the ground and into the groundwater.
4. Desalination - We reviewed two ways that can be used to desalinate water.
Mar 22 2012
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). Your assignment is to read the arguments/watch the clips and answer the question at the end of the post. 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….While not part of the assignment, this 8 minute animated YouTube Video called “The Story of Bottled Water” has more info on why bottled water became so popular (“manufactured demand”) as well as other issues, if you have the time.
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?
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 2010 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 BPA and pthalates into bottled water. Some studies suggest BPA and 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. There similar collections of plastic in other oceans.
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: Bullsh*t 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! Please post a response/comment…
Here is a brief 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.