Tuesday, July 16, 2013

Living With Acid Rain

Rust on the back of a solar panel. 
Our farm is located downwind from an actively erupting volcano. Thus we deal with what's called "vog" -- volcanic fog. This vog contains sulfur dioxide, which as it travels and reacts with moisture in the air, becomes sulfuric acid. This attaches to moisture droplets and minute particles in the air. Depending upon your distance from the volcano, the vog may have more sulfur dioxide or more sulfuric acid. Where the farm is, we get a bit of both. Luckily we also live near a pali which diverts ocean breezes up the side of the mountain, thus pushing the vog a bit higher up the mountain in our little zone. We usually miss the worst of the vog in that it passes by 1/4 mile higher up the mountain. Only 1/4 mile! Not much of a distance. But it makes all the difference in the world as far as making our farm livable and comfortable. Therefore from sunrise to sunset we seldom experience vog. It's during the night when air moves down the mountain that the stream of vog may pass over the farm. We seem to usually just get the edges of the path of the vog, but occasionally we get the full brunt of it. Perhaps twice a year we get vog enough to burn the tender leaves of lettuce and taro.

Vog gives us our acid rain, And acidic it can be! If we are experiencing vog and also get a good rain, the pH in our catchment tank sometimes plummets to 5 or even 4.5. I've never measured the pH of the rain itself, but that's an idea. I think I'll do that someday. Might be quite revealing. 

It doesn't take a pH meter to tell you that we live with acid rain. Just look at the tender leaves of lettuce or taro. They get burnt. The petal tips of many flowers, such as protea, also show signs of being burnt. Two other very apparent indicators are smooth concrete surfaces (they show signs of etching) and exposed metal (it rusts). 

Rust is a major problem. Major! And it doesn't have to be rained on to rust. Wherever moisture can travel, things will rust, though not as quickly as it would out in the rain. Tools inside a shed or garage will rust quickly if not treated with oil or grease. I even see tools rusting on the shelves in the Ace Hardware store! For real! 

Metal out in the rain really suffers. Fences rust away really quickly. Rooves rust if not kept painted and watched over carefully. Even catchment tanks can rust away. Garden tools suffer dramatically with rust, shortening their lives. A wheelbarrow can become ruined in a year, or two at the most. Leaf rakes rust away in less time. The rivets on your fiberglass ladder rust away. Even the clasp on your dog's collar will rust.

I use Ospho to treat rust. It's phosphoric acid and chemically reacts with rust to change it from iron oxide to iron phosphate. But it's not a cure-all, not a one time-walkway solution. The rust will come back if you don't keep on it. Since it's a liquid, I can use a small paintbrush to treat hard to reach spots. Another item I use is lithium grease. I coat the hinges and mountings of gates, door hinges, heads of bolts, screw heads, spots on the truck that have gotten nicked, tools, locks, etc. In the house I use car wax on the refrigerator, freezer,  range, and anything else with iron metal. 

The vog eats up window screens in a hurry. So when the screens corroded away, we replaced them with the plastic kind.

Another thing I try to protect from the rain is my laundry. Once upon a time I would have left the clothes out on the line, letting the rain soften them. Not anymore. The acidic rain seems to shorten the lifespan of clothing. Weakens the cloth really fast. I notice that the clothes line and ropes in general don't last as long as they should either.

Since I rely upon my gardens for food, I find that I need to watch the soil pH. I use crushed , burnt coral as a substitute for limestone. Home processed bones also go into the soil. Plus I also use wood ash in conjunction with microbe inoculated biochar. The coral and bone seem to work slowly, but add needed calcium and phosphorus. The wood ash/biochar mix raises the pH fairly quickly and provides potassium, trace minerals, and soil microbes.

I've talked with farmers closer to the volcano who have some severe problems with the vog. They have installed overhead irrigation in order to combat the acidic vog and rain. One farmer even resorts to injecting baking soda into the irrigation system on especially bad days.

Living with acid rain is a pain. It's costly and uses valuable time. When I lived on the east coast, the news media would sometimes cover stories about acid rain and speculate what it would be like living with it in the future. Well folks, the future is here, on Big Island, Hawaii. Be forewarned! 

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