The Water System
Last Updated: January 04, 2006
Most recent images first; plan drawings, text and additional references at bottom...

The completed well site!

 

On the opposite side of the tank is the CDF/Fire access valve. The valve handle is locked to a flange mounted on the tank to prevent accidental (or mischevious) discharge. During the winter months, the valve is enclosed in a foam wrap to prevent the ball valve from freezing. The white vertical unit in the background is the water level indicator board, situated to be visible from the road below.

 

The inlet, float (electrical) and outlet lines [from right to left] plumbed. All above-ground piping and conduit is galvanized steel, with galvanic isolators, wrapped with insulation foam and an outer wrap of pipe wrap (for UV protection of the foam). The white substance where the connections go into the ground is white paint to provide UV protection for the PVC galvanic isolators.

 

After the tank was delivered, it poured for the next 2 weeks. As we could, we worked in the rain to get the tank plumbed since once we connected to the pipeline we could no longer fill it directly from the well. As we got the bottom connections in place, we started the pump to allow it to take advantage of the brief periods of sufficient solar (not sunny, but thinning clouds!). We were lucky to get 200 gallons pumped each day (and we needed to get the 2500 gallon reserve filled before the water was available to us); but thankfully we had filled the water line just before switching it over and our day-to-day use is minimal. Finally, after 2 weeks of rain, the tank had filled enough for the water line to start receiving water, and just in time! On a good (sunny) day, the system pumps over 1500 gallons. One good sunny day was what it took to get everything finished, including making a custom float mount for inside the tank and to touch up the paint on the outside.

 

Drilling holes in the foundation for the tank anchors (3/4" x 16" threaded rods). Note the tank outlet at left center -- this is where the water main will connect to, leaving a 2500 gallon reserve (accessed by another bung & valve) for fire-fighting.

 

Setting the tank into position

 

Moving the tank to the foundation

 

Righting the tank

 

Preparing the mats the tank will sit on (asphalt inpregnated fiber board to provide isolation and protection of the tank).

 

The water tank arrives! (10k gallons, steel tank with food-grade epoxy coating inside, 10' diameter by 16' high)

 

Static testing the water system before the tank installation. 1600' of line, 6 isolating valves, numerous hosebibs and 2 fire hydrants with no leaks!

 

Water, gray water and septic trenches opened at the bottom of the propery

 

Routing water (and electrical conduit) to the excavated house pad. Note black corrugated shell on water main is for extra protection for running under a road where heavy vehicles (e.g. concrete trucks) might travel.

 

One of the many big rocks my poor backhoe had to 'chew' through... (that's a full size swiss army knife leaning against it)

 

The line past the staked PV site towards the greenhouse and main garden locations

 

Starting the line across the PhotoVoltaic(PV)/work structure pad (excavated house site is on the left with the truck in front)

 

The upper hydrant completed (above the house site) with valve box in foreground

 

Setting one of the two hydrants at the house site

 

View of the periodic valve boxes set on native rock built up to support it. The red handle allows us to isolate segments of the line while the faucer (w/freeze-protected vacuum breaker) is for local irrigation.

 

Backfilling a completed water line segment

 

Irrigation spur with (bagged concrete) thrust block in background

 

Simple thrust block at a water line direction transition

 

Installing the water line (~1600' long, ~235' elevation change, 2" PVC pipe)

 

 

Setting the well outlet. Note the water meter (so we can monitor our water usage)

 

First test -- we've got water! (the pump, PV panels, etc. all work!). With a 190' deep well, solar powered, we are pumping around 5 gpm (and it even pumps from early morning to early evening!).

 

Setting the well pump into the well (Grundfos 6SQFlex)

 

Curing the slab (ponded and covered with plastic)

 

Finishing the tank foundation as the sun goes down

 

The big pour (13 yd3, 17.5% pozzolon)

 

Last cleanup and form boards oiled (ready for the pour!)

 

Final checks

 

The rebar in place and forms ready

 

Getting ready for the rebar (2 layers in an 18" slab)

 

The foundation moisture barrier added

 

Leveling the sand layer

 

Packing the foundation gravel bed

 

 

The water tank foundation, dug out and ready for gravel

 

The completed well PhotoVoltaic array (4x Kyocera 125G panels) and pump controller with the completed well head in the background. The PV mount is made by a local WIllits manufacturer (2-Seas). I haven't yet wired everything in.

 

The PhotoVoltaic mount pole and foundation hole.

 

Mixing concrete for the PhotoVoltaic (PV) solar mount and pump controller

 

Drill samples from the specific depths

 

Drilling the well

 

Setting up the drill rig (Morrison Drilling)

 

Cutting the well road

 

The Water System

Many of the homesteads in our area employ springs, either natural or augmented by digging or horizontal drilling or they import water from commercial delivery services. Working with a Mutual Water company for many years taught me a lot about the quality of water and the potential for contamination (upstream activities such as faulty septic systems, etc.). In addition, several we have talked to who have springs suggest that they endure periodic drying up.

We decided that based on our usage for the homestead, research facility and agriculture we needed to have a higher relability to our water source. Our projected usage isn't that high, we just cannot afford to lose precious agricultural crops. We considered rainwater collection but given our estimated usage, the cost of sufficient (storage) tanks was prohibitive, not to mention the amount of land they would occupy. In the end, a well with moderate storage was determined the best approach and provide us with the water security we desired.

When we first looked at the property, we searched for indicator plants that might suggest a spring or shallow water source. We didn't find any. We did have a stream bordering one edge of the property but from looking at other properties in the neighborhood, we knew it was well used and we didn't want to contribute to its degradation. We then hired a dowser, actually the first of four (counting ourselves), and in each case the same spot was identified. This was a point at nearly the highest point on the property in a fractured sandstone deposit.

We spoke with several well drillers and the experience (and equipment they used) ranged all over the map. We finally settled on the more expensive one and we are happy we did -- he had the equipment to do the job right, the first time, and to provide the complete service from drilling to well prep to tank selection and delivery.

When considering a water system, be sure to check with your local fire department (in our case, both the regional fire department and the California Department of Forestry or CDF). There are requirements as to water storage for fire as well as road access to the water storage. Altough we are building with full consideration of the potential of wildfire (e.g. ferrocement or steel structures), we still decided to ensure CDF's needs were met as well as the addition of a couple of small fire hydrants to serve their and our needs. If a hydrant is a consideration in your plans, make sure you size your water main accordingly (e.g. fire fittings are typically 2-1/2" so a common 2" size line is perfect!).

In addition to mandated fire storage (typically 2500 gallons), one needs to determine their needs and size the overall tank in accordance to the storage desired. In our case, we were looking for a minimum of 10 days storage for emergencies in addition to the fire storage.

The well pump is another area of careful consideration. From past experience (with the water company), I had some understanding of what happens to wells when they are overused. Basically, when one draws the full production of a well, they run the risk of creating what is called a 'cone of depression' which in layman's terms is the settling of the surrounding soils around the well casing as the water is drawn out, eventually making the layer surrounding the well impervious to water passage. Although our well produces in the tens (if not over a hundred) gallons per minute, the use of a positive displacement, low volume pump sized to our needs (and no more than 1/2 the well production) does the job just fine. A point to remember is that the storage tank is like a battery, storing water until you need it. A storage tank, not the pump, is what you draw from, so spend your money there and don't risk damaging your well by overdrawing it. On that same note, be careful in the type of water treatment you use -- 'ozonators' are not suitable for metal tanks as they will cause the metal to oxidize and corrode!

One last note regarding the water piping. All types of pipe materials, with the possible exception of polyethylene, are in question as to health. However, don't select a pipe type just because someone says it is the best. The most important consideration is it's pressure capacity. In our case we had ~240 feet of elevation from the tank to the homesite; which equates to a pressure of over 105 psi! Doubling the expected pressure (to accomodate surges, etc.) means we needed to look for a pipe material that at the diameter desired (2") could withstand 210 psi. PVC or metal pipes were our only choices. PVC is fraught with health warnings but closer examination reveals these apply to high heat or fire. A buried water main has neither. Where our line does come above the surface, we transition to galvanized for the simple consideration of it lasting through a grasslands fire. As to freeze protection, the well pump and the fire hydrants are drain-back; while the irrigation bibs are sited below ground in rock-filled valve boxes (thermal storage). Think your system through for the worst case and you will be glad you did.

For those interested, the well driller was Morrison drilling & Pump, Inc. based out of Laytonville, CA (800.835.8078). The supplier of solar components, including the well pump, was Advanced Power of Calpella, CA (707.485.0588, Advanced Power). The tank manufacturer was BH Tank, Inc. of Salinas, CA (831.424.2951).

 

Plans
Adobe .pdf format

Overall Plan
Well / Pumping Schematic
PV / Controller Mast Foundation
Valving, Hydrants, etc.
Water Tank Specifications
Water Tank Foundation

 

Additional Reading for Those Interested:

The Home Water Supply, Stu Campbell, Storey Press, 1983
Wells and Septic Systems, Max and Charlotte Alth, McGraw-Hill, 1992
Water Storage, Art Ludwig, Oasis Design, 2005
Solar Water Pumping FAQs