WELL WATER

Well sighting and drilling

There is a lot that goes on behind the scenes that owners never hear much about. Selection of well site is a good example. Presumably, when land is subdivided, the developer has to determine reasonable building envelopes and well sites. We never thought to investigate these factors before buying our land. Our builder and the local health department found an appropriate well site, and we were never consulted.

Our well drillers only had to drill 145 feet to get twenty gallons per minute (“gpm”) - an excellent result. Some of our neighbors had as little as two gallons per minute at depths in the hundreds of feet. A “Well Completion Report” was submitted by the drilling company to the Orange County Health Department, giving the yield at 100 feet (fifteen gpm) and 130 feet (an additional five gpm), and stating the casing depth (63 ft). Another company installed the well pump, a three-quarter horsepower, eight gallon Red Jacket®, and the water line was sized at one inch to the pressure tank. Our pressure tank is 40-gallon size, supposedly “oversized.” We later added a boiler drain in order to measure the gpm at the pressure tank, and found we had ten gpm at the pressure tank. This ten gpm was important as far as our options for water treatment, since some filtration media require more gpm (particularly for backwashing – see below) than others.

I never knew to specify in the building contract the size of the well pump, well line or pressure tank. We were therefore dependent on our builder to specify these, and we were fortunate that our builder had high standards. As the owner of the well pump company told me, “I always put oversized pressure tanks in Mr. Hartley’s houses.” Ideally, however, I should have specified in our contract that a reasonable gpm must be achieved at the pressure tank.

Water testing

After our well was drilled, chlorine was added to disinfect the well, an application was made for well testing, and some time later the Orange County Health Department came to take water samples. Private companies will test well water for a fee, and in North Carolina, there is water testing at low cost from the State Laboratory of Public Health, through the local county health department. I opted for the maximum analysis which the state offered, including testing for pesticides and coliform bacteria.

Our first water testing report showed typical results in that the water was modestly “hard” (73 milligrams per liter of calcium and magnesium, which translates [divide by 17.1] to 4.27 grains per gallon). The harder the water, the harder to bathe and wash clothes in, and the more tendency to form “scale” in water heaters, on coffee pots, ice makers and the like. Below is one chart I found which rates hardness[1]:

ClassificationMg/L or PPM (parts-per-million)Grains/Gallon or GPG

Soft0-170-1

Slightly Hard17-601-3.5

Moderately Hard61-1203.5-7.0

Hard121-1807.0-10.5

Very Hard180+10.5+

Our water showed high levels of iron and manganese (3.59 mg/l and 0.52 mg/l respectively), and we were given a notice that these levels of iron and manganese were “not within acceptable or recommended limits.” We had very low levels of arsenic and trihalomethanes. Our pH was 6.8, slightly acidic. No coliform bacteria or pesticide residues were found.

When our untreated well water comes out of a spigot, it looks clear. But let it stand for just a few minutes and it quickly becomes orange. This is the result of the oxidation of (clear) ferrous (dissolved) iron to (orange) ferric iron. The orange ferric iron will stain clothes – you cannot do laundry in it. It will also quickly stain toilets, tubs, and showers. In my case, it even stained the exterior of our house, when I watered bushes with a sprinkler using untreated water. Iron oxides later clogged the sprinkler.

Subsequent water tests showed even higher levels of iron: 4.93 and 4.21.

Researching water treatment options

I researched water treatment on the Internet, read Jim Dulley’s bulletins, compared notes with neighbors, and spoke with many salesmen of local water treatment companies. Most salesmen of water softeners could not tell me how salt-efficient their systems were (see discussion below). I also spoke to a few non-local salesmen who were kind enough to take some time with me, and I eventually bought a system which I had installed by my plumber, on the advice of a long-distance water filter salesman whom I found through a distributor of healthy paints and other household products.[2] Later, I found a local water treatment installer, Chuck Lewis, who was knowledgeable, honest and willing to help me substantially modify my system according to my own research.

I found a good number of Internet sites to be well-written and helpful, but no one site had all the pieces of the puzzle. This appendix is my attempt to integrate what I have learned from these sites and my other research.

I ran across some Internet sites which discussed large municipal systems. Reading about municipal systems taught me that individual residential water treatment is an inefficient and much more expensive way to treat water. After years of having municipal water and sewer, I can now appreciate what a bargain they were.

One experienced water treatment installer told me that many individuals pay around $6000 to $7000 for a residential water treatment system (sold on commission), and then finance that system at very high interest rates, resulting in a real initial cost of $13,000 to $14,000. Then they pay a monthly fee to maintain it.

I was looking for a system which would have a reasonable installation cost, but most importantly, have a low ongoing maintenance cost.

Water treatment options

We considered the following residential water treatment systems: 1) water softener (ion-exchange/salt-based)/regeneration systems (also called water conditioners), 2) water filtration systems, 3) reverse osmosis (“RO”) systems, 4) ultra-violet (“UV”) light systems, 5) magnetic systems.[3]

Magnetic systems

Magnetic systems, which use magnets to alter the shape of calcium and magnesium ions in much the same way as catalysts (see KDF below), are controversial, yet they are used successfully in many industrial applications. However, there was no magnetic option for us, since magnets cannot be used with water which contains significant amounts of iron.

Ultra-violet (UV) systems

Since we didn’t have any bacterial contamination, I saw no need for a UV system, which is only used to eliminate “microbiological contaminants” (such as bacteria and viruses).[4]

Reverse osmosis (RO) systems

I resisted RO systems, since these are “point of use” (under sinks or in showers) rather than whole-house systems. RO also uses a lot of water and produces a very small service flow (some only fifteen gallons of purified water PER DAY, and requiring three to ten gallons of untreated water to make a single gallon of purified water[5]). Using an RO system can affect the function of an ice-maker in refrigerators, if it lowers the water pressure too much.[6] The RO membrane usually has to be replaced every two years[7]. RO has the greatest range of contaminant removal[8], and can remove arsenic and salt, which are otherwise not well-removed by other kinds of filtration.

Water softeners: ion-exchange (salt-based) systems[9]

At first, I assumed that we would use a water softener, since these were really the only systems with which I was familiar. Most of my neighbors had some sort of water softener, sometimes combined with other systems, such as UV. As my research progressed, I learned that water softeners are ion-exchange systems which work by passing the water through specially treated polystyrene beads (“resin” or “zeolite”), charged with sodium or potassium ions. As the water flows over the resins, an ion exchange takes place so that the sodium or the potassium replaces the calcium and magnesium ions in the water. Essentially, one is trading calcium and magnesium in the untreated water for either sodium or potassium in the treated water.

In these systems, the salt used definitely gets into the drinking and bathing water. I did not want sodium in my water, since it has negative health effects for humans and gardens, and I also wanted, if possible, to retain the calcium and magnesium, which have beneficial health effects. Salt can also damage a refrigerator icemaker and lead to poor quality ice.[10] Salt also hastens the corrosion of anode tubes in water heaters.[11]

If I had chosen a water softener, I would have wanted to use potassium chloride instead of sodium chloride, since added potassium is generally much to be preferred in the diet and in the garden (assuming I watered with treated water) than sodium. Using sodium makes the treated water a bit “slimy” in feel, whereas using potassium does not. Using potassium chloride would have increased my operating costs, however, since potassium chloride costs two or three times more than regular sodium chloride. There are also sometimes problems of caking, mashing or bridging of potassium chloride in some systems.

Periodically, the resins in water softeners must be “regenerated” with (salt) brine which reverses the ion exchange, and the waste water with the manganese and calcium is washed into the sewer line along with excess salt regenerate. Most systems are “co-currently regenerated”, meaning that the service flow and the regeneration flow go in the same direction, and untreated water is used for the regeneration. Better is a “counter-current system in which the regeneration flow runs in the opposite direction from the service flow. Best is a system which is both a counter-current system and a duplex system, which uses two tanks controlled by one valve, only one of which tanks regenerates at any given time, using soft water from the non-regenerating tank, rather than untreated hard water, for the better regeneration of the resins. A duplex system also eliminates the necessity for a reserve water capacity to get the unit through the day so it can regenerate at night.

If I had chosen a salt-based system, I would also have looked for a system which:

1) operated at a capacity of at least 4000 grains of hardness per pound of salt;

2) used fine mesh (40 to 50 mesh) resins which require less gpm to backwash;

3) contained a resin bed depth of a minimum of 24 inches over sufficient under-bedding (the material at the bottom of the tank, which covers the basket/distributor);

4) had a “free board” of 50%. (The free board is the empty space in a tank above the resin bed);

5) used a demand-initiated regeneration (DIR) valve, since it ensures that regeneration is initiated as needed;

6) used counter-current regeneration in a twin-tank (duplex) configuration.

Based on these criteria, I would almost surely have chosen a Hague® or Kinetico® brand.[12]

Water softeners are not water purifiers, and would not remove bacteria or solids. If I had had bacteria in my well water, I might have combined, as many systems do, the water softener with a UV system. If I had had high levels of arsenic, I would have had to use RO systems under my kitchen sinks and in my shower area. Water softeners can remove iron[13]. In addition, many water softeners do not handle well hydrogen sulfide (rotten egg smell) which often accompanies high iron levels.

Water filtration systems

Water filtration systems do not use salt and ion-exchange; instead, they use a variety of filtration media in backwashing or non-backwashing tanks. With the exception of carbon block, I reason that all media should be backwashed at some interval to remove solids and prevent the compaction or channeling of the media.

Iron

Iron in water presents special filtration challenges. Our situation is a common scenario: ferrous iron (appears clear in water) in the well water, which quickly turns into bright-orange ferric iron (oxidized at point of use in toilets, tubs, showers, taps). Iron is more easily filtered in its oxidized, ferric state. Iron can be oxidized by aeration (exposure to air) and chlorination (exposure to chlorine). Aeration appealed to me as the least toxic alternative, until I learned that aeration was complicated by the necessity to have a certain level of dissolved oxygen in the water (which we did not have). To raise the level of dissolved oxygen, one can inject soda ash, which will raise the pH which in turn can improve the effectiveness of the filtration media. Chlorination is cheap, simple and fairly innocuous, since it is used in highly diluted concentrations. It does require subsequent filtration in a way which effectively removes the chlorine as well as the iron precipitate.

Service flow

Backwashing (regeneration) flow

Tank size and sequencing

Both salt-based (ion-exchange)/water softener systems and water filtration/backwashing systems usually involve one or two fiberglass tanks holding some kind of either filtration media or resins (in the case of water softeners). One or both of the tanks are topped by a valve which triggers regeneration and/or backwashing in the middle of the night (when presumably little water is otherwise being used). I could see no advantage to getting more than the basic fiberglass tank, along with a basic Fleck 5600 backwashing valve.

The size of the tanks is critical to “service flow” (the rate of water used in the house) and “backwashing flow” (water used to backwash the filter media to remove the filtered elements and keep the media clean and loosely packed). The diameter (not the total volume) of the tank is a key element contributing to service flow. It is also important that the “riser tube” inside the tank (which transports the filtered water from the tank) and the porting and bypass valves be of a one-inch diameter.[14] The difficulty is that “most filter media require a significantly higher backwash flow than the service flow they support.”[15] Most houses need at least 5 to 7 gpm of “service flow” (the rate of water used in the house).[16] But to achieve that rate of service flow for some filter media would require a tank for which the backwashing might require 10 gpm. The solution is often to install two smaller (8 to 10 inches in diameter) tanks instead of one large tank, and to install them in parallel (half of the water flowing through each tank) rather than serially. Thus it is necessary to specify in the construction contract that at least 10 gpm be achieved at the pressure tank, in order to accommodate most service flow and backwashing flow requirements.

Chlorination/filtration systems

We have now installed two water treatment systems, the second system replacing and being a modification of the first.

Both systems use chlorination as the first step in oxidizing and precipitating out the iron. Water from the well is pumped to the pressure tank in the garage. From the pressure tank, untreated water passes through the first 25-micron polypropylene string sedimentation filter and enters a 120-gallon mixingtank. At the point of entry into the mixing tank, a chlorine solution is injected into the untreated water supply by a Chem-Tech chemical pump from a 25-gallon chemical tank filled with a mixture of simple liquid bleach and water.

The injection of chlorine is triggered by a sensor at the pressure tank which is itself activated by a drop in the water pressure in the pressure tank. I monitor the water in the mixing tank with a chlorine pool-testing kit so that the chlorine concentration will be kept at between 0.5 and 1.5 parts per million (“ppm”). I take the water sample from a boiler drain at the top of the mixing tank. In the mixing tank, the ferrous iron is oxidized to ferric iron, causing the ferric iron to precipitate out. Some of the ferric iron precipitate accumulates at the bottom of the mixing tank. A boiler drain at the bottom of the mixing tank is used periodically (every three to six months) to flush the tank by attaching a garden hose to the boiler drain and allowing the precipitated iron to flow out to the ground outside. A good deal of the ferric iron precipitate remains to be filtered out in the backwashing filtration tanks.

The chlorine also serves as a sterilizing agent. If my untreated well water had contained high levels of organic compounds, however, the chlorine would also have produced carcinogenic trihalomethanes which would then also required removal by filtration (probably more coconut shell carbon); however, the more layers of filtration, the more potential for drops in water pressure.

Original filtration: KDF55 plus coconut carbon shell

plus three polypropylene string filters

In our original system, the water from the chlorine mixing tank passed first to a second 25-micron polypropylene string filter and then in sequence to two fiberglass media tanks, each 36 inches high and eight inches in diameter.

Originally, the first tank had a Fleck 5600 backwashing valve and was filled with “KDF55”. KDF55 is a 50-50 copper-zinc alloy material which is one of two different copper-zinc media used in “Kinetic Degradation Fluxion” (“KDF”). KDF is also called “Redox” (Oxidation/Reduction) for its electrochemical oxidation effects.[17] KDF media comes in two varieties: KDF 55 and KDF85. The copper-zinc KDF media act in a catalytic manner to 1) remove chlorine, 2) kill bacteria, 3) transform (but not remove) calcium and magnesium ions to a chemical structure which does not form scale, and 4) remove hydrogen sulfide. It also acts mechanically to filter out solids, such as iron precipitate.