Modern Water Systems

Drinking water just isn’t what it used to be.

It can taste awful. It can smell. It may carry disease-causing organisms, and plug pipes and fixtures with rust and dirt.

No longer can hikers sip from crystal-clear mountain streams because of lurking, invisible bugs that will do a number on the gut of the unwary.

Sometimes, clean, sweet water is hard to find in a faucet, and many carry it home from the grocery in plastic jugs.

And that’s on shore.

At sea, it may be safe to say that water is better than ever-or that at least it should and could be.

For hundreds of years mariners have filled tanks from shore facilities and then dropped mooring lines and set off for distant ports, draining or pumping water as needed. If they were lucky, sailors in the 19th Century made port before the water ran out. Many were not lucky.

Surprisingly, a great many recreational boaters act no differently today. Their greatest worry is finding a place to fill tanks with clean water.

Those who harbor hop in North American waters generally can be assured the water they take aboard at marinas is pure and safe to drink. It may smell and taste of chlorine or have other strange odors, however, and if the delivery pipes are old, the water may be loaded with rust and scale.

For most boaters, that’s the way it is.

But water is not always safe, or it at least occasionally fails to meet federal and state standards limiting the presence of bacteria and chemicals. On my desk as I write is a newspaper article that reports that residents of a nearby Puget Sound-area community-one with a popular marina-had been ordered to boil drinking water after routine tests found E. coli and fecal coliform bacteria (evidence that human or animal waste has contaminated the source) in two water systems.

On a trip to Southeast Alaska last year we stopped at a small British Columbia port where a small and obscure sign warned visitors to boil community water before use. Fortunately, we saw the sign before connecting our hose.

And don’t forget the 1993 incident in which thousands of Milwaukee residents became ill from drinking water carrying a microorganism known as Cryptosporidium.

Trouble is out there, and it will get those who are not attentive.

The Answers

Doing nothing to improve or protect water quality on board may yet be the first choice for many boaters. They pour it in and pump it out. And, generally, it’s risk free, although the water may not taste or smell good. But it’s not the best choice.

The first step beyond doing nothing is to install simple filters that screen out dirt and rust, as well as chlorine and the soup of chemicals that are created when chlorine is injected into drinking water. They also will deal with naturally-occurring junk that finds its way into public water supplies and that may either taste bad or pose some threat to health.

Water filtration is an old business in this country and an amazing variety of filters have been developed for industry, business, and homes that are served questionable or bad tasting water. Many adapt easily for boaters’ use.

The second step is a big one: Beyond filtration is the use of ultraviolet light to sterilize water, and then the ultimate system-reverse osmosis water makers that almost magically make sea water fit to drink.

These systems may be designed to fit the personal desires and cruising demands of all kinds of boaters, from harbor hoppers to ocean crossers, from the smallest of boats to megayachts. Simple and inexpensive filtration systems will deliver clean water, while complex and expensive filter/water maker/UV systems will guarantee the delivery of a flood of safe and pure water without relying on shore supplies.

Because Seattle water comes from clean, protected mountain sources, we don’t worry much about quality when we fill the tanks on our boat.

But when we visit marinas where water may have suspicious origin (lakes, ponds, bogs) we thread a simple high-density polypropylene filter on the hose used to fill our water tanks to eliminate sediment and rust.

Ours is an Instapure R-20, made by Teledyne Water Pik, and is available in almost any hardware store. It’s nothing more than plastic thread wrapped tightly around a tube, but it is large enough that it doesn’t slow the filling of water tanks.

It doesn’t remove chlorine, pesticides, other chemicals, bacteria, viruses, or naturallyoccurring, disease-causing cysts (Giardia and Cryptosporidium) from the water. The label clearly warns that the R-20 is not effective in treating water with bacteriological problems.

The second thing to do in this simple system is to install a granulated charcoal filter beneath the galley sink. It will rid water of chlorine and eliminate the color, taste, and odor caused by other organic matter, and trap nearly all other contaminants as well. Usually these filters are connected to a separate tap on the sink and water flows slowly because it must penetrate a block of resistant charcoal.

The use of filters is catching on as people become more aware of the problems of dirty water, or simply want to rid water of unpleasant tastes and odors.

Even though boat tanks may be clean, water held a long time may develop odd tastes and odors. Additives (various chemicals, concentrated lemon flavors, even white wine) may be poured into a freshwater tank in an attempt to cancel the taste, but filters work better and provide additional protection, too.

On Quadra, we use a Multi-Pure Corp. filter that will remove sediment, viruses, bacteria and Giardia and Crytosporidium cysts, as well as ugly-tasting chlorine and other chemicals that wind up in a city’s water supply.

There is nothing left in drinking water flowing from the galley faucet that tastes or smells bad or will leave one with a rumbling gut.

The Multi-Pure, which fits in a two-piece stainless steel can, traps everything and anything larger than 0.5 micron.

A micron is invisible. There are one million microns in a meter, so imagine slicing something about 39 inches long into one million pieces- and then cutting one piece in half. That’s a half micron, about the thickness of a slice of deli ham.

Giardia cysts are seven to 12 microns in size. They do not pass through a 0.5 micron filter, and also are killed by contact with chlorine.

Cryptosporidium cysts are about four microns in size. Nor do they pass. This is reassuring, because chlorine doesn’t kill them.

Don’t challenge a filter, however, by asking it to do too much. If there are notices posted recommending that water be boiled because of E.coli, fecal coliform bacteria, or other bacteriological contamination, don’t count on the filter alone. Boil, or don’t use it.

We find that one Multi-Pure filter, costing about $50, keeps the water tasting fresh and clean for a year. We buy a miniature version for the ice maker; there’s no point in pouring good stuff over yucky ice cubes.

Bill Parlatore, editor of PMM, learned to rely on a General Ecolog y final filter called the Sea Gull while he was a sailor. “I never had a worry about the water coming out of this filter,” he says.

Some boaters use both sediment and granulated charcoal filters when they fill water tanks. This doesn’t make a lot of sense, because chlorine, which will keep bacteria under control in the tank, has been removed. This could turn a water tank into a bacteria farm, and who knows what will come out the galley faucet?

Granulated charcoal filters should be installed near the point of use, so that clean tasting water has only a short run to the tap and coffee maker.

What Others Do

Dean Mosier, an owner of Passage Maker Yachts in Seattle, said serious Pacific Northwest cruisers are installing 600 gallons-per-day (gpd) reverse osmosis (RO) water makers, with an increasing number adding UV light units as a final treatment.

Mosier also suggests customers consider what he and his wife, Katie, do aboard their liveaboard home, a 39-foot Krogen: Install a sediment filter on the intake line (they use a Racor), using it every time they fill, and a granulated charcoal unit under the sink. “It’s simple and effective,” he says.

Lenard Lee, owner of Ballena Bay Yacht Brokers, with offices in San Diego and Alameda, California, says his customers choose water treatment based on their cruising choices.

“In Southern California, people think about going to Mexico, and a lot of 110-volt water makers are aboard, although there is a trend to 12-volt systems on boats without generators,” he says. “In Alameda, more filters are used, in some cases with UV, because if they are cruising north, plenty of water is available.”

On the Great Lakes, many boaters simply fill their tanks at the dock and use it as it comes, says Karen Schuler, who with her husband, Ken, owns Trawlers Midwest in Manitowoc, Wisconsin, on the shore of Lake Michigan.

They have installed only one water maker for a buyer. Water makers work in fresh water with adjustments to the pressure system and careful filtering of intake water, particularly in rivers where the water may be muddy.

“Taste is the issue,” Karen says, adding that many customers simply buy bottled water to beat that problem.

Although water makers are popular with boaters bound for Southeast Alaska, not everyone uses them.

Chuck Worst, a marine electronics expert (and PMM electronics editor) has made many trips north without a water maker and never has run short.

When a friend bought a boat, Worst helped check it out. There was a water maker, but it was a ball of rust and it quickly was tossed.

The 55-foot boat carries 400 gallons of water, which they found to be adequate for four persons for a week. Taking water aboard at larger towns, and using a granulated charcoal filter to eliminate taste and odor, they have done well without making their own.

But others, without the huge carrying capacity of the boat Worst cruises aboard, think water makers are best. With a machine producing pure water on demand, boaters may hang out in isolated areas as long as they wish. Visits to Alaska towns are dictated by something other than the need to fill a water tank.

If capacity is a serious problem, there are a number of auxiliary bladder tanks available. They may be hard to place, and the weight may affect a boat’s trim, but they do work.

Zip, Zap

Some might say that filters present a passive line of defense against water contaminants. They just sit there and do their job.

A more offensive and perhaps last-ditch addition to a boat’s clean-water system could be an ultraviolet light. UV long has been known as a potent killer of unfriendly organisms (friendly ones, too; many bacteria found in water are harmless to people), but it is just beginning to come into use aboard pleasure boats.

A UV light can be bought as a stand-alone unit, or packaged with a pair of filters, for as little as $600. One filter will take out suspended particles larger than five microns, while the second is a 0.5 micron unit that will trap the smallest microorganisms.

Anything that escapes those filters moves into a stainless steel disinfectant chamber where a

UV light, enclosed in a pure fused quartz cylinder, zaps it. UV lights are available in 12VDC and 120VAC. Models typically chosen will process several gallons of water a minute, enough to satisfy all drinking-water demand. Larger ultraviolet zappers, capable of treating all water used on a boat, also are available.

One manufacturer estimates the UV light will last 7,000 hours. The lamp should be left on whenever the boat is in use.

Some boat yard installers now recommend adding UV lights and the accompanying filters, whenever a water maker is sold. However, they still are not yet widely used.

Tom and Judy Blandford, who have been cruising Mexican waters on their boat, Gracias, say they don’t see them in common use, even though UV would seem to be a welcome final purifier for water of questionable quality.

Len Dickinson of Sunburst Boat Co. in Seattle, whose major business is the installation of water systems, has equipped large yachts with sediment and charcoal filters, and a UV system in the intake line for cruising in Mexican waters. In a belt-and-suspender approach to water quality, other filters would be installed at the point of use.

Make Your Own

Reverse osmosis (RO) water makers have been on the market for about 25 years and now are the central element in water systems aboard many passagemaking yachts. Standard Communications made the first RO water maker in 1976; a successor company now manufacturers HRO and Sea Recovery RO systems.

HRO builds water makers for hotels, condos, cruise ships, fish plants, and oil-production platforms. “But the marine (market) is our bread and butter,” says Al Leon, a company official.

Many other firms also offer water makers; there is great choice and stiff competition in the market place.

With a watermaker, a cruiser may cut the cord-or the hose. Don’t worry about the next fill-up.

Machines that can produce hundreds, even thousands of gallons a day are available. Kiss the navy shower goodbye. Don’t feel guilty about rinsing after a swim, or hosing off the boat after a day of cruising in sloppy water.

Reverse osmosis is not magic. It’s just nature at work in a mysterious way.

Osmosis is a natural function in which a liquid passes through a semi-permeable membrane, moving from a dilute to concentrated solution. For reverse osmosis, add pressure (a lot of pressure- up to 800 pounds per square inch) to the concentrated solution (salt water in this case) and only water molecules make the trip through the membrane toward the dilute solution. The salt and other dissolved materials accumulate in a brine solution and are drained overboard.

A RO system removes about 98 percent of dissolved minerals, including sodium chloride and a long list of other chlorides, and nearly all colloidal and suspended matter.

Dissolved minerals constitute about 3.5 percent of sea water by weight. In other words, there are about 35,000 parts of dissolved solids in every million parts of salt water.

Most RO water makers reduce the salt content to about 100 parts per million, far below the level at which it can be tasted.

Water making through distillation brought unlimited supplies to seafarers with the development of the steam engine in the 19th Century. While it worked for large vessels, distillation was not something that could be adapted by pleasure boaters because of size, complexity, and cost.

Reverse osmosis became possible with the development of membranes made of cellulose acetate or polyamid composites, and highpressure pumps that drive water molecules through the microscopic holes in the membranes.

Shaped either as a sheet or fine, hollow fibers, the membrane is placed in a cartridge known as a reverse osmosis module.

All water makers use the RO process and similar membranes. The differences are in pumps, process controls, the type and arrangement of filters, plumbing, and electrical systems.

Water makers take up a lot of space. Although manufacturers box all the components in one package (which may be four feet or more in length), they also sell components that can be placed where there is space.

Filtration Concepts, Inc., a California manufacturer of water makers and filtration systems, says elements of its Dolphin series may be scattered through a boat-some parts on engine room bulkheads and others in the lazarette. “Connecting and mounting hardware is simple and effective and reliable,” the company says.

Regular care is vital to a water maker’s long life. Like a passagemaker’s diesel engine, a water maker thrives with use.

“I have an attitude about water maker maintenance, and that is that it’s just like engine maintenance,” Worst says.

Conscientious boaters make regular checks in the engine room while under way; if there’s a water maker aboard it should be checked faithfully as well.

Water makers require flushing after each use, which takes a couple of gallons of pure water. Normally, this is automatic. At the end of a season additional flushing and treating the membrane with chemicals-it’s called pickling- is required to keep it healthy over a winter.

Brad Pierce, of Marine Sanitation, Inc., in Seattle, said many people just don’t want to understand what a water maker does, and how it does it. “That’s the worst thing,” he says.

Pierce emphasizes the need to use a water maker regularly, to properly lay it up at the end of the season, and to keep it from freezing. Successful operation depends on preliminary filters on intake water to remove algae, dirt, plankton, and other floating debris. “If you never check the (filter) canisters, I’ll give you my phone number,” he says.

Point-of-use charcoal filters are important, too, Pierce says, because water makers are not purifiers. The filters also will remove the taste and odor of sulfur that sometimes comes with water maker-produced water.

Keep It Clean

RO systems and membranes are sensitive and easily damaged or upset by contamination of supply water. Chlorine and petroleum products will destroy the membrane, for example.

Filtration of the raw water is emphasized by manufacturers and contractors to remove plankton, algae, petroleum, and sediment. Depending on the geographic area to be cruised, a RO water maker may have several filters on the inlet side.

Usually, these are cartridge filters that can be reverse flushed for cleaning. In some cases, a heavy and bulky sand filter may be used for this task.

For obvious reasons, manufacturers recommend operating water makers only while under way.

First, they say, water in marinas may contain gas, oil, sewage, and other debris not good for the equipment. Harbors into which streams flow may contain sediment, which can quickly plug up inlet filters.

Another reason for underway water making is that it allows operation of a generator (needed for 120VAC systems) at a time when its noise is not noticeable. For 12VDC water makers, it’s the only way to keep batteries topped.

The Blandfords bought a 12-volt water maker for Gracias, believing they would make water while cruising. The opposite is true, for them.

“We make much more water at anchor than we do while traveling,” he says. “I thought the quality of water at anchor would not be good enough, but that turned out not to be the case.

“If you spend any time in the Sea of Cortez, and that’s our favorite cruising ground, a water maker is almost a necessity. There is so little fresh water in the Sea, that it is very common for local fishermen to ask cruisers if they have extra water.

“Water makers are great, but they require a lot of care and attention.”

How Big?

There are water makers of all sizes on the market, from hand-pumped units that produce a few pints an hour, to giant systems capable of creating tens of thousands of gallons of water daily. They are found on cruise ships, work platforms, military vessels, and, increasingly, at marinas, resort hotels, yacht clubs, and even golf courses.

Production estimates for most water makers assume the sea temperature is 77 degrees. If the ocean is colder, as it is in the Pacific Northwest, Alaska, and throughout Canada, a water maker produces less.

Len Dickinson of Sunburst Boat Co. asks his customers to determine how many persons will be aboard and how they plan to use fresh water. “And then I double what they say, for once they have a water maker in use, consumption will go up because they no longer are concerned about water supply,” he says.

Some owners install small heat exchangers to raise the temperature of intake water, to improve efficiency. Dickinson says this is dangerous because if there is any ferrous metal in the exchanger, rust will form and damage the membrane.

Heat exchangers may be found on oil platforms and other major installations, but their purpose is to keep the membrane from freezing.

Leon of HRO Systems believes heat exchangers “pretty much are unnecessary,” particularly on smaller units. They are not costeffective, he adds.

A typical Sunburst customer owns a boat of about 50 feet and installs a 500-gpd water maker. The owner will cruise three or four months a year, often to Southeast Alaska.

Not quite so common are customers who have much larger yachts and cruise to Mexico, Japan, and Europe, Dickinson says. Those yachts often carry two water makers, for redundancy’s sake.

Now, 500 gallons a day sounds like too much water. How could anyone use that much?

Few boats will. The point is that most boaters operate the water maker while under way, possibly four or five hours a day, and produce about 125/150 gallons of potable water, sufficient for showers, cooking, and whatever. So choose a high volume unit to reduce operating time and to keep water tanks full.

That 500-gpd unit will cost $7,000/$8,000, installed, Dickinson says.

Larger units typically are AC powered. And, normally, boaters crank up the genset while they are under way and then switch on the water maker. The additional machinery noise is swallowed up in all the other sounds of a boat at sea and that means, when it’s at anchor in a tiny cove the only sound will be ice cubes tinkling in a glass.

The Blandfords bought a 12VDC water maker and Tom now says “it was a big mistake.” He admits he thought he knew more than the salesman about how it would be used-but he didn’t.

“The problem with a 12-volt unit is that it does not make as much water as a 120-volt water maker,” he says. “We have a 12 kW genset, so power would not have been a problem.

“Bottom line: buy as big a unit as you have room for and energy to operate. None of the cruisers I know complain about making too much water, but a lot complain about making too little,” Blandford adds.

DC models are popular with others, however. Obviously, they would include boats without AC generators and those that don’t need to produce water for a crowd of guests.

An innovator in the DC field is Spectra Watermakers, which has developed a pump it says is far more efficient than most. The Clark pump draws about one ampere hour of electricity for each gallon of water produced.

“Nobody else provides nine gallons an hour on eight and a half ampere hours,” says Matthew Hartwig, sales manager.

Spectra recognizes the water maker market goes beyond DC units. It is working on development of a 1,000-gpd AC system.

Generally, units rated at more than 200-gpd require 120VAC service (some larger units also may be powered directly by the propulsion engine).

Although today’s water makers are automated and carry out much required maintenance without owner attention, they still require TLC from their users.

RO system-produced water requires some treatment in its storage tank to prevent the growth of algae and bacteria, although a pointof- use UV light would cleanse the water, too.

Hartwig of Spectra Watermakers suggests using about one capful of household bleach for every 30/40 gallons of stored water. “And then I recommend a charcoal filter to take out the flavor,” he says.

Good Choices

Today, there is no need for a boater, either passagemaker or weekend cruiser, to tolerate water that tastes bad, smells worse, or may be contaminated with sewage or a mess of manmade chemicals. Nor is there any reason to do without water or to scrimp on its use.

Water-system planning is flexible, with something to fit every need, and costs to match nearly every budget.

It can be as simple as a granulated charcoal filter beneath the sink. It can be as complex as a 1,000-gpd watermaker–or a pair of them.

Whatever the need, there is a choice that works. And there always should be lots of water–sparkling clean, fresh water.