The most important thing that the human race did to save itself from the devastating and deadly diseases was to clean up the drinking water.... Now, why are we having a problem?
Let's try to make sure everyone is one the same page. One comment from last night indicated that perhaps I should break this down further. No problem! And don't feel unhappy with yourself if things are a bit sketchy. As you read more things will make more sense to you. Also, the chemistry part of the story of water is important because, the structure and the basic behaviors are exactly the issues we get into trouble with when it comes to water. We ought to know better that if we do certain things we will ruin our drinking water... (if anyone with a computer can educate themselves on the 'internets'.... so can politicians, bureaucrats and business owners and operators, farmers.... etc... who are spilling their stuff around... so, why aren't they????..... hmmmmmmm).
Water is a wonderful solvent for most of what we get into... which is why we take showers and baths and wash our clothes and other things in it. We also use soaps and detergents that bind to things that water, by itself, cannot dissolve.... like grease and oil. But remember, there are components, that have in their molecular structure, like soap and detergent, enough of a 'charge' or a polarity that will allow some mixing.... and this can be very bad. The bad thing about MTBE (the note from last night) was that the EPA chemists DID know that this gas additive, used to increase the combustibility of gasoline, would escape from underground gas tanks (there is no perfect tank!!!) at stations and get into ground water (see MTBE in Santa Monica, California)
Go here for nice stuff on Polarity of water...
Here and here are wonderful easy sites to quickly understand the basics of water structure and what polarity is and non polar substances are.
So, what was it that I was talking about last night? Oh, yeah. The bad things that we put in contact with our drinking water.... and how easy it is to ruin the stuff. Hey! Water tastes icky sometimes when water districts let the stuff stand for too long in their tanks and pipes. The water tastes musty or like dirt. Our noses and taste buds can pick up a lot of the natural pollutants, but there are some things we can't because the amount is so small ( and we don't have the receptors in our tongues or noses) but is still toxic to us in some way. Also, water districts that recycle water (if you live down stream from another city you ARE drinking toilet water) just don't have the technology to remove things at parts per billion (and trillion) that may cause reactions like the estrogen that women take for birth control or from the phthalates (softener for plastics) from plastics or PCBs (oh man, this stuff is everywhere and bad!!!) that act like estrogen.
A lot of the stuff (like toilet stuff) which we put in our water can be broken down by other organisms but if there are tons and tons and tons of the stuff.... then the living things in the lakes, streams, rivers, reservoirs - that we use to store and our drinking water - which take in oxygen (fish, insects, and such) die. This increases the number of organisms that don't need oxygen, and which feeds on dead tissues... Then if that loop continues for a while..... or never stops, we get dead zones (Gulf of Mexico). Even if all we put in the water is nitrogen (like urine and fertilizers -> bad, bad) we get blooms of algae. And many types of algae (cyano-bacteria or what used to be called blue-green algae) are toxic, too. there are lots of common species of cyano-bacteria that kills!
So, we should not be loading up in our water systems with effluent from urban areas, farms, wood pulp and mills, and industries that have lots of nutrients as waste products (or that will degrade into nutrients). We have done this little 'STUPID' since time began for us as.... microbes..... You would think we would learn! And this problem only gets worse as our populations grow. And our industries and farms grow, too.
I promise I will get to watersheds.... they are SO wonderful, complex and key to knowing what to do for your communities.... I must sleep. too many things to dooooooo......But I will be back tomorrow.