Category: Natural World

Nearby Coal Plant’s Leaking Coal Ash Pond


View Ameren’s Coal Power Plant in a larger map

Jeffery Tomich had a good article last month on the leakage from the coal ash pond at a coal burning power plant near to our school. While the leakage appears to pose no real risk to us, it is a serious environmental issue at a local site that a number of students drive by on the way to school.

I’ve annotated the following excerpt from the article based on the questions my students asked when we talked about the it.

Since Since 1992, a coal ash pond next to the Ameren power plant here has been … hemorrhaging up to 35 gallons a minute [into the local groundwater].
…
At many [other] sites, trace metals in coal ash including lead, mercury, arsenic and selenium have been found in groundwater at levels that exceed drinking water standards.
…
In 2007, a U.S. Environmental Protection Agency report identified 63 sites in 26 states where the water was contaminated by heavy metals from coal ash dumps. That was more than a year before an estimated 5.4 million cubic yards of coal ash sludge escaped an impoundment in Kingston, Tenn. The sludge spread across 300 acres, and 3 million cubic yards spilled into a river.
…
The waste is created from burning coal to create electricity. At Labadie’s ash ponds, it’s composed of fly ash, a fine, talc-like powder that’s captured by filters in the plant’s stacks to reduce pollutants released into the air, and bottom ash, a coarser material that falls to the bottom of coal boilers.
…
a report prepared by Robert Criss, a Washington University professor, identified several dozen private wells along the bluffs near Labadie Bottoms that could be at risk of contamination. Contaminants could infiltrate from shallow alluvial soils to the deeper Ozark aquifer [(see also USGS, 2009)] tapped by residents for drinking water, according to the report.
…
Ameren believes the leaks don’t pose an environmental threat. But because of ongoing concerns, and because the EPA has asked the utility to monitor them, Ameren will make repairs to the ash pond by the end of the year

— Tomich (2011): Leaks from Ameren toxic waste pond in Labadie stir fears in St. Louis Today.

More information from the local environmental group, Labadie Environmental Organization:

The ash overflow in Tennessee: see Dewan, 2008.

Milking Goats

Learning how to milk goats.

Part of the afternoon chores at the Heifer Ranch was milking the goats. It was not something required of the students, but since our barn was located right next to the goats’ milking barn, a lot of them volunteered to try it out.

Carefully milking a goat.

Most used the somewhat dainty, one handed technique, and I’ll confess I was among that group, but a few students (see first image) really got into it.

A good producing goat (doe) can produce about 3 quarts per day (McNulty et al., 1997).

After milking, the goats’ teats are dipped in iodine solution (25 ppm recommended by McNulty et al., 1997) to kill any germs and prevent infection.

Sanitizing with iodine solution.

As for the green splotches on the backs of the goats. On our first morning at the Heifer Ranch we had walked past a paddock with about half a dozen goats. A student noticed the green and asked why. Fortunately, we had a guide to explain a little about the basics of animal husbandry – apparently, the marks indicate which goats are likely to be pregnant.

A Galactic Cluster

A cluster of galaxies, each with millions, or billions or trillions of stars. This ridiculously awesome image (think about it) was taken by the Hubble Space Telescope (via Space Telescope).

The galaxy cluster MACS J1206. Galaxy clusters like these have enormous mass, and their gravity is powerful enough to visibly bend the path of light, somewhat like a magnifying glass.

These so-called lensing clusters are useful tools for studying very distant objects, because this lens-like behaviour amplifies the light from faraway galaxies in the background. They also contribute to a range of topics in cosmology, as the precise nature of the lensed images encapsulates information about the properties of spacetime and the expansion of the cosmos.

–NASA, ESA, M. Postman (STScI) and the CLASH Team: Hubble image of galaxy cluster MACS J1206

A Fatal Dose of Bananas

Banana: 1 μS.

In my last physics exam, I asked how many bananas would it take to deliver a fatal dose of radiation. This question came up when we were discussing different types of radiation and looking at this graph. One banana gives you about 0.1 microSieverts, while the usually fatal dosage is about 4 Sieverts. That means 4 million bananas. Michael Blastland uses the instantly fatal dosage of 8 Sieverts to make his estimate of eight million.

Usually Fatal Dose: 4 S.

My students were insistent, “Would eating four million bananas really kill you with radiation?”

My answer was, “Yes. But other problems might arise if you try to eat four million bananas.”

Bug Power Generator

Most power plants create electricity by spinning a magnet while it’s inside a coil of wire. That how coal power plants do it, it’s how hydroelectric power plants do it, it’s how wind plants do it, it’s even how nuclear power plants do it; solar power panels don’t do it this way, however. The coal and nuclear plants, for example, boil water to create steam which spins the turbine that rotates the magnet.

In theory, you can use any type of power source to spin the turbine, including people power. On bicycles, you can use them to power your lights. But because you’re now using some of your mechanical energy to create electricity, it will slow you down a bit. Newer, hub dynamos, however, are apparently quite efficient.

So, in theory, you could use any type of animal to generate electricity. Including, for example, using bugs to charge your iPod.

I love how he holds up the voltmeter 34 seconds into the video to prove that his device works.

Fog on the Downs and Lake

Early morning.

The first few mornings at Heifer were cold. About five or six degrees Celcius (in the 40’s Fahrenheit) at sunrise. The large barn we slept in had been “converted” from housing horses to housing people. Apparently, horses prefer wide-open, drafty places.

But a warm sleeping bag goes a long way. And being forced to wake up just before the break of dawn does have certain advantages. I’m rarely up and about in time to capture the morning light. With the early morning fog drifting across the slopes and rising off the lake, those first few mornings were wonderful for photography.

Sunrise is usually the coldest time of day. After all, the Sun’s been down all night, and is only just about to start warming things up again. Cold air can’t hold as much moisture (water vapor) as warm air, so as the air cools down overnight the relative humidity gets higher and higher until it can’t hold any more – that’s called saturation humidity; 100% relative humidity. Then, when the air is saturated with water vapor, if it cools down just a little more, water droplets will start to form. The cooler it gets the more water is squeezed out of the air. Water vapor in the air is invisible, but the water droplets are what we see as fog. Clouds are big collections of water droplets too; clumps of fog in the sky.

Early morning fog drifts over the lake.

Tarantulas near the Global Village

Tarantula encountered on the path between the Zambia and Thailand (at the Heifer International Global Village).

We ran into this young tarantula on the path between the Zambian and Thai houses in Heifer International’s global village in Arkansas. We were taking the tour, and while this young fellow (probably male according to Zaq our guide) was not part of the regular schedule, we were lucky to find him. While tarantulas are venomous (mildly), and some have stinging hairs, their bites are about as painful as a bee sting (Warriner, 2011). But they are large, and, since most of us have a visceral fear of large arachnids, they’re pretty awesome to encounter (charismatic megafauna – is the term I like to use).

Zaq branished the wooden Spoon of Silence and shouted, "Hey. Take a look at this."

Tarantulas arrived in Arkansas about 8000 years ago (Warriner, 2011) at the height of the warmer, drier climate that followed the melting of the great North American glaciers about 10,000 years ago. The climate of Arkansas has gotten a bit wetter since then, but the spiders survive in isolated, drier upland areas (according to the Arkansas Tarantula Survey), like bits of grassland surrounded by forest. Pretty much like the grassy slope between the Thai and Zambian houses in the global village.

They can live to be 10-20 years old, which I think is pretty impressive for a spider.

Tarantulas usually just hang out at the mouth of their burrow and ambush anything that looks like prey to them. This includes insects and other spiders, but sometimes even lizards and very small mammals.

Identifying tarantula species is apparently difficult because their differences are usually quite subtle. The Arkansas chocolate tarantula (Aphonopelma hentzi), “is presumed to be Arkansas’ only tarantula species” (Barnes, 2002).

If you annoy them (with something like the Wooden Spoon of Silence) tarantulas will rear up and look menacing. Which is pretty awesome.

A slightly annoyed tarantula.

Science Starts with Careful Observation

Page 1 of my notes: Diagram of our mysterious mixture.
Sealed jar with a number of unknown substances.

The middle school started science this week with a mysterious jar of unknown substances: a couple immiscible liquids; some plastics and metals of different densities.

As they try to separate and identify the mixture they’ll be learning about handling potentially hazardous materials, material physical and chemical properties (like density and pH), and a little chemistry.

But the first thing they need to learn is how to take notes. Science starts (and ends) with observation. Careful observation. And most middle schoolers need mentoring to make sure their notes are rigorous.

To this end, after they wrote up their observations of what was in the jar, I put together my own notes as a general reference. This is not the only way to take notes, but I’m going to have them amend their own notes to make sure they’re neater and have as much detail as possible.

Page 2 of notes on the mysterious jar.
Page 3 of notes on the mysterious jar.