dear all, here are the notes Kristi sent me with mine interwoven. thanks for taking such great notes, kristi! king and i are going to add to the greenmac.com/roundmountain webpage with these notes plus maps, photos, and diagrams king and tom have been putting together. all best, gaby

Water meeting 2-3-06

Present: King, Gaby, Phil, Dave (for part of the time), Artemis, Kate, Kristi, and Tom for 10 minutes.

Fig 1: Drawing by Phil Cool (larger view)

Discussion:

Water testing, Coliform and flushing the pipes:

The water tests that were taken at the farm house kitchen sink yielded the presence of Coliform (a normal bacteria that forms in enclosed spaces where water is present) and from the ozone tap where our drinking water comes from; no presence of coliform or lead. Additionally, they tested the Ag water at their house only for Round-up, which was not present.

Larry Desmond (the person we consulted re: creation and functioning of our 250 gallon Sand filter which is larger and much slower than normal ones, therefore cleaning the water more thoroughly) states that having Coliform in and of itself does not make the water un-potable, and in fact he considers ours to be potable. It is the presence of e-coli and fecal matter that is an indicator of the possibility of the single-celled parasite known as Ghiardia, and these were not present in the testing samples that Artemis and David took.

There was discussion about testing the water from the upper units, as the piping to the Farm house is only about 3 years old, whereas the piping on top is much, much older and may actually yield different results. Many years ago, Kristi's water test from the kitchen tap yielded coliform, e-coli, and fecal matter; since her home is at the end of the water piping system, this may indicate that the pipes, at least over to the Yurt Flats side, may be unclean.

Instead of testing, at the moment, we decided to mechanically flush the water pipes that come after the holding tank, using the same pump we use to backflush the sand filter tank. The pipes must be flushed in 3 parts with each unit's taps open so as not to rupture any pipes due to the higher pressure involved (90 psi instead of the usual 20 to 30 psi): first, mechanical flushing, then flushing with chemical cleansing by adding either Grapefruit seed extract or Food Grade Hydrogen Peroxide, then finally a last mechanical flush to remove as much of the debris as possible caused by the chemical flush. Kate will discuss the use of the chemical substances with Larry to make sure they eradicate parasites as well parasite eggs.

Back flushing: We discussed the process that occurs when the Sand filter is back-flushed which must be done when the water flowing into the distribution tank drops below the 1.5-3 gallons per minute rate (or when, as tom says, the water is like the missouri: too thick to drink, and too thin to plough). Tom keeps daily tabs on the tanks and is the person who conducts the back flushing process. The process is as follows:

The valve between the distribution tank and the sand filter is turned off. A pump is used on a separate pipe line that runs from the bottom of the holding tank to the bottom of the sand filter tank. The water is pumped through the bottom of the sand which is also stirred from the top and discharged through a pipe at the top of the tank onto the ground. This process is done for about 20 minutes or until the water flowing onto the ground is
clearer.

Clearing the water also displaces the balance between the good bacteria which is eating bad bacteria in a layer of sludge on top of the sand, but clearing must be done to reinstate the water flow into the holding tank. In the past after the pump is turned off, Tom has simply opened the valve between the Sand filter tank and the distribution tank. Since the balance between the good and bad bacteria takes a few hours to be re-established, Tom made a suggestion that he simply wait 2 hours before turning back on the valve so the possibility of releasing tainted water back into the holding tank would be diminished, which is a very good and simple solution regarding contamination. YEAH TOM!

We will bring up the idea of paying Tom at the next meeting for his daily surveillance of the tanks and every 5-6 weeks doing the back flushing.

Second line of defense-Ozone or Ultraviolet system:

We then discussed how to keep the pipes free of the unhealthy parasites in the event our lake ever became infested and as a second line of defense. We decided to research the possibility of having either an ozone or ultraviolet system installed after the distribution tank and before the holding tank. Both systems work best when the water flowing through them is translucent (e.g., being able to see your feet at the bottom of a bath
tub full of water).

Though even without the rains our water is very dark-black tea colored (At least at the end of the line), Kate will discuss with Larry the cost, size and viability of the use of either of these types of systems with our Sand filtered water which can become very dark with silt after it has rained for a few days and the lake is stirred up. (If we need the same size ozone system as the one at the Farm house, it would be approx $1000, and if the Ultraviolet system would work with the cloudiest of our water, $700).

We would like to pay at least $50 to Larry for his consultation, time and attention and will bring this up at the next meeting.

Meeting adjourned.

Greetings RM community:

I just had my consultation with Larry Desmond, and want to write it up before I forget what I learned. I am in the process of doing more research, as It turns out that UV may not be able to handle anything but microorganisms like viruses and bacteria (including giardia), so I'm doing more research on that. Also to find out whether ozone takes care of those organisms.

Thank you Kristi for taking such good notes,and Gaby for writing them up. Very thorough!

One point of clarification, however, is that we don't know for sure that it takes only two hours to reestablish the schmutzecke (layer of beneficial organisms) on top of the sand after we back-flush. Two hours is the time it takes when you "harrow" or rake the sand to increase the flow. Our back-flushing method (pumping water up through the sand and schmutzdecke) is unorthodox, and Larry said it sounds like a pretty major disruption. He doesn't know how long it would take for the schmutzdecke to reestablish itself, and says that that is a good reason, among others, to have a back-up system. (Until the schmutzdecke is re-established we are not protected).

From consultation with Larry Desmond

General Info:
1) All water lines should be buried so they aren't exposed to sunlight, both because sunlight breaks plastic down and because light can get through unburied lines and encourage growth in the lines; (Phil says that ours are buried except on the north side where they go into the tank, and the line that comes to the sand filter from the lake - so that's probably not a problem);

2) Sand filters should always be run at the slowest rate possible to reduce turbidity. For our domestic (non-agricultural) usage 1 gallon per minute should be sufficient; (Phil's been running ours between 1.5 and 3 gal/minute; he'll try slowing it to 1, so we should watch to see if the water gets clearer, and we'll find out if that rate keeps up with the demand;

3) The pipes can be flushed with food grade hydrogen peroxide (35%): 1 cup per 1000 gallons;
4) if we flush the pipes and then run only sterile water through them, there should be no future growth of organisms in the lines;

5) UV light is generally preferable to ozone for sterilization (cheaper, quieter, less maintenance) unless there is iron in the water. UV works by interfering with the DNA of microorganisms so they can't reproduce. It doesn't actually kill them. Micro-organisms are apparently only a problem if they reproduce...a tapeworm, on the other hand, doesn't need to reproduce to wreak havoc in a body, and can live 20 years (the longest one on record was 100 feet); I'm trying to get information about UV and large parasites, as I said above.

6) UV units can be installed at each house ($588 plus tax each) or one could be installed for the whole system ($750-800 plus tax, approximately);

7) a 5 micron filter before the UV lamp would be extra insurance and is recommended; (Q: wouldn't it get clogged all the time?; Q#2: would it catch large parasite eggs that escaped the sand filter during flushing? Cost $280;

8) ozone units cost about $1500 now; they go on sale in April for $1300. They don't come in different sizes except for hot tubs. Larry didn't seem to think a hot tub system would work for drinking water, but I should probably press him on that. (King doesn't like the idea of moving the existing ozone system upstairs because he feels insecure about losing our tried-and-true source of drinking water downstairs. But some of us realized that the downstairs system is "overkill" (550 gallons are kept ozonated every hour of every day, and probably less than 600 gallons are actually drawn off in a month), so we are wondering if the system downstairs should be replaced with a smaller one.

More info as it comes in...

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