Joined: Oct. 2012
By the end of winter we finally had enough cold weather for the bedrock to very noticeably freeze solid!
As expected the flow rate slowly decreased until there was no detectable flow at all. The new re-circulation loop worked great for keeping the system flowing after having achieved success, in which case there is no place to send the cold and (from observations from electronic temp probe) temp goes below (as calibrated using ice bath method for lab thermometers) 0 C.
This is what the (in above photo at bottom right where hoses go) water feeder/injector ended up looking like. The two large 3/4 inch hoses and black plastic 3/8 inch hose barb that is pressed into the borehole form a tripod that makes it easy to insert and remove. To help prevent the 12 volt valve from freezing-up it was mounted as close as possible to the much larger circulation water flow that goes from basin to pump then back again, in a loop that keeps water moving fast enough to not freeze. When valve is open a small amount of the flowing water goes into the borehole, now with a 14 inch sediment collection tube at the bottom to seal off the (near frost line) lowest layers and focus water to the top two feet.
The 3/4 inch hose line is connected to a 1/8 HP Little Giant 5-MD-SC Magnetic Drive Pump circulation pump that's good for 27.5 feet of head pressure, which is less than pressure from a typical water faucet and in this case reaching full pressure requires blocking the return line, in turn causing freezing of water inside it and pump. As in filling water balloons until they burst: too much water pressure can damage paper thin layers. The goal has been to use as little water and pressure as possible to saturate the top two feet of strata.
After a cold night the pond/basin looks like this:
When super-chilled it looks more like this:
Towards the very back are aluminum offset printing plates upon which water chills a little before reaching pond. Using two flow rates a valved garden hose sprays the area with water, either at a slow rate that almost keeps up with water demand and fast rate that turns on when a float switch indicates that water level is a little low. In this experiment (even where just force of gravity) two angels are as you can see helping to direct the water into the pond.
Valves are currently all automatic so it's mostly a job of watching and waiting for the next emergency to attend to. To stay going all night the circulation pump flow had to be used like a deicer by directing at a large float switch float that splashes the water outwards. All nozzles and other restrictions including 3/4 inch lawn sprinkler system valve placed at the end of the 3/4 inch circulation hose have had to be in a hurry removed, after plugging up with ice. The center of the float switch has (basin valve on) red (basin level OK) green and (borehole valve open) blue LED lights inside that at night through nearby window make it easy to monitor.
All of the major objectives were achieved. It was first easily possible to get water to flow horizontally then out the sides of the block, and channel the tinkle of outflow to the thousand+ gallon runoff basin that helps prevent basement and street flooding and drains into an extremely deep fault that is barely even dampened by the amount of water normally used. Most was lost to evaporation, pipes bursting at night then water coming out full blast for hours, and icing that causes overfilling or squirrels that try to get a drink by climbing the refill hose and I later wake up to it spraying into the air instead of basin and the tracksite turned into a tilted skating rink.
The second objective was to get water to flow from one hole to another on the other side of the 20x40 foot bedrock rectangle. Then the third was to freeze at least one to two feet of the entire surface, and in the event of (as happened) borehole freezing up: without causing damage to the system.
I'm confident that over the winter there were numerous freeze/thaw cycles that went to various depths. It's hard to know how well this actually worked for separating the layers of interest, but from what I could see from the surface the conditions were ideal for faster than usual weathering in the most solid internal areas, instead of opposite condition that primarily only causes weathering of the outermost edges caused by rain seeping in.
There was also a supply of pond water zooplankton delivered into the layers. I'm not exactly sure whether keeping the inside damp through the spring season would help munch away whatever cements the more inert stone layers together, but use of microbes is another possibility. Latest information indicates that the voids between sedimentary layers were caused by biofilm layer forming between sedimentation events, which later decomposed to become an empty gap.
Warmer weather has now settled in. I don't expect any more opportunities for the system to chill down enough for the borehole valve to open. I normally hate winter, but this year it's sad to be over.
The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.