“Water, water everywhere, nor any drop to drink.” Samuel Taylor Coleridge penned these words in the “Rime of the Ancient Mariner.” He referred to a fateful ocean voyage in the 1800s, but it could very well reflect our need for clean drinking water today.
To understand why water is becoming widely scarce and increasingly expensive, one must begin with a primer on water itself.
A view from outer space
Our earth can hold 366 million trillion gallons of water, but of this unimaginable volume, 97.5% of the total is in our oceans. Of the remaining 2.5% fresh water, about 70% is frozen. That leaves only ~0.75% above land (clouds), on land (rivers/lakes) or under land (aquifers). Of that remaining <1% fresh water, we must share it with all plants, animals and billions of humans.
Finally, the process of creating clean water strips out an additional ~20% in transporting, treatment and storage. Add to this picture the fact that water is unevenly distributed around the globe, and you are left with a monumental challenge to satisfy humanity’s needs. (Source: April 2010 issue of National Geographic.)
A view at the molecular level
Water consists of two atoms of hydrogen bonded to one atom of oxygen. The structure produces a “bent molecule” at a 120 degree angle. This gives it polar characteristics (with oxygen possessing a negative charge, and the hydrogens having a positive charge). The polar nature of water allows for a unique behavior. Often referred to as a “universal solvent,” it can dissolve ionic materials, and interact with other polar molecules.
When compared to other liquids, pure water has very high density. Water also “wets” with many surfaces. This means water “sticks” with most surfaces (hydrophilic), while repelled by a few others (hydrophobic). Water is also one of only a few liquids with density decreasing, and volume increasing, when it freezes (i.e. ice floats in liquid water).
Lastly, of importance, is the ability of water to form unique combinations with other liquids. This can be the ability to combine with other liquids and change the physical characteristics of the starting materials (e.g. coolant in a car radiator, normally composed of equal parts water and ethylene glycol). Car coolant experiences a lower freezing point, and higher boiling point, than either water or ethylene glycol alone.
Many of these characteristics come into play in everyday situations. (See Handbook of Physics and Chemistry, sections D, E, F, for a science-based reference with more details.)
The importance of water
It’s not an exaggeration to say water is the basis of all life. We humans are composed of ~60% water (instrumental in all phases of metabolism, being both ingredients and platforms in our health processes). We humans can go without eating for ~2 weeks, but we must consume water daily or risk dehydration.
At the same time, the type of water we drink becomes crucial. The government defines drinkable water as “potable.” Potable water must contain certain types and amounts of minerals to taste pleasant and be useful to the body.
At the same time, other types of minerals and compounds can result in an unpleasant taste, or progress to a level detrimental to your health. For this reason, all source water must be processed to potable standards to ensure we get the right water to maintain a healthy body.
The qualities that make water so important to our existence also can become counter to the process of making potable water. Take for instance the universal solvent attribute: while it is important to metabolism and therefore well-being, it also makes the creation of potable water laborious and expensive.
Water generally “hates” itself and “loves” almost everything else. Put another way, water wants to have lots and lots of “stuff” in it. The more material it takes on, the more stable it becomes. To make water drinkable, it must be processed to remove some of this “stuff.” Whether processing involves sedimentation, filtration, ion-exchange, and/or reverse osmosis, it is a process/or processes that involves time, costs and quality control.
That brings us to SLVWD
For those of us who live in San Lorenzo Valley, we are blessed to have a wonderfully wholesome natural supply of source water. Percolating through layers of soil and rock formations, then flowing into and down the creeks of the Ben Lomond Mountains, the water is naturally filtered to make it some of the best source water in the state.
Those committed professionals who work in the San Lorenzo Valley Water District put in long hours to deliver potable water to each of the ~8,000 connections in the Valley. (Source: slvwd.com, “About Us” tab.)
Unfortunately, this is a job that requires balancing the need for water, with an ever-increasing cost to produce (e.g. moving large amounts of water over great distances, ever-increasing testing requirements to monitor final product, and natural disasters that test our resolve).
While we must practice cost restraint wherever possible, and search for new technologies to bring in additional efficiencies, we must also recognize that cost going up is a necessary consequence of the unreliable supply of water, coupled with unforeseen challenges. Lest we forget, we also have an obligation to the plants and animals we share our valley with, to ensure their share of water is provided as well.
The challenges for SLVWD are many and complex
Take the simple fact that water is dense. What this means practically is the cost of transporting water is enormous. The average monthly PG&E bill for the District is around $50,000, just to move large quantities of water over great distances.
Water’s ability to “wet” surfaces means surfaces that touch water can stay wet for extended periods. This can lead to the perfect condition for microorganisms to thrive, leading to foul tasting water, and potentially causing sickness. The best way to minimize this threat is to keep water moving.
In this way, microorganism populations are kept in check, and there is less likelihood of dissolved solids becoming a problem. Keeping water moving, even in storage tanks, is expensive (see PG&E bill above).
Water’s ability to expand when it freezes makes above ground piping to become a prime target for problems. The expansion of water freezing in pipes could cause the pipe to burst. It could also cause small chunks of ice to form and collect at a junction, thereby clogging the pipe.
Pipe leaks take a large share of District labor to continuously monitor and fix, currently the 8-man Field Service department. This represents ~25% of total District staff, just to address leaks.
Water quality testing is continuous, extensive and costly. Water’s ability to pick-up (i.e. dissolve) minerals and microorganisms calls for rigorous testing to ensure “potable” standards are maintained. This testing involves Water Treatment Operators’ time, and tens of thousands of dollars for outside services, just to meet state monitoring requirements.
These are but a few of the many challenges the District faces on a daily basis. Bottom line, drinking water can be expensive.
An argument can be made that future cost-effective increases are needed. Increases should be made in light of planning for the future, hand-in-hand with other resource demanding options (e.g. increased fire flow and better engineering solutions).
Keeping the cost of water at a reasonable level for ratepayers is a difficult, but necessary, part of the solution. The upcoming water rate increase should provide the impetus for all ratepayers to read and understand information being made available by SLVWD, in order to make an informed decision on our water rates for the next five years.
Lewis Farris is a resident of Felton and former SLV Water District Board Member.
