The caller found us on the Internet. The youthful inquirer had a booming voice, in staccato Japanese, and I had to hold the telephone away from my ear.

“Greetings, hello, hi, ciao. Please recommend the biggest, baddest filtration system which removes everything from this smelly brown water,” he shouted. “Don’t worry about what it costs … We just dug a 100-meter well; a doctor customer wants his dream house with a view on a mountain perch, but for heaven’s sake, the road is called Sulfur Spring Road, and tell me, how is our Daisuke doing?”

He was referring to Daisuke Matsuzaka, the starting pitcher imported from Japan by the Boston Red Sox and nicknamed “Dice-K.” The pitcher was from the caller’s hometown, and the caller had been an avid fan. He called my company, located in Boston, at 2 p.m. Eastern time, and the time in Japan was 3 a.m. He was still up and about, most likely an entrepreneur.

Noticeable sulfur odor
I asked the caller for the analysis, and the water was indeed pretty bad: turbidity 20, color 8, pH 6.4, iron 13 ppm, manganese 1.4, fluoride 0.22, hardness 6 grains per gallon, organics 4.3, TDS 560, and a noticeable sulfur odor.

In my rusty Japanese, I started by telling him that honesty was the best policy, and to tell the doctor that the well water was terrible. I suggested that the caller should promise to do his best, but that, water chemistry being what it is, he might not succeed in the first go-around.

The caller then laughed and told me that he owns a water purification company, he has a small office and a secretary, and the doctor is her father. The plot thickened.

Starting with dirt and color
“The dirt and color have to be knocked down before anything,” I told him.

I recommended starting with a mechanical screen filter, either a turbo-clean, auto-flush type (automatic) or simple screen type (manual). This, I told him, could be followed with a type of bag filter.

I then suggested adding a reverse-flow acid neutralizer, consisting of an in/out head atop a dome home tank with calcite. This, I explained, should raise the pH to close to 7.0, or neutral.

Fe/Mn/H₂S reduction
Continuing my advice to the caller:

I mentioned four types of backwash filters to reduce/remove iron (Fe⁺²), manganese (Mn⁺²) and hydrogen sulfide (H₂S), and all of these benefited from adding an air injector and a vent in the line. Two were for cases with a large amount of sulfur, and two others were specifically designed to address the presence of H2S.

Based on my experience, the system using manganese greensand would be the heaviest hitter, the brute, the best arsenal for the awful water such as the caller’s. If there was any doubt, I told him, the greensand system could be rolled out to meet the challenge.

A greensand setup looks like a regular softener, with a main tank and a small brine tank nearby, and the installation and operation are identical.

Greensand specs
Manganese greensand is formulated from glauconite, a mined natural mineral, and is capable of oxidizing, precipitating and filtering out Fe⁺²/Mn⁺²/H₂S.

When greensand’s oxidizing power is exhausted, the media bed is regenerated with a weak solution of potassium permanganate (KMnO₄). One and one-half to 2 ounces of KMnO₄ by weight per cubic foot of greensand should be adequate for regeneration.

Based on data obtained from one major manufacturer, the media is black, weighs about 85 lbs. per cubic foot, and has a bead size of about 0.30-0.35 mm. The bed should be at least 30 inches high or higher.

Manganese greensand can handle water with a pH between 6.2 and 8.5, but contaminant removal appears to get easier with a higher pH value. It should be used at a maximum temperature of 80 degrees F (26 degrees C). The service flow rate is 3-5 gallons per minute per square foot (gpm/sq ft), and an intermittent flow of 8-10 gpm/sq ft is possible.

The maximum practical limit for ferrous iron (Fe⁺²) or manganese (Mn⁺²) in such a system is 15 ppm, and for hydrogen sulfide (H₂S), 5 ppm.

RO filter is final touch
Manufacturers offer greensand systems with various tank sizes, showing you roughly what to expect in service and backwash flow rates, as well as other data.

It’s always better to be conservative, to go with a bigger-capacity system and have some wiggle room. In the caller’s case, based on his design flow rate, a 2.75 cubic-foot model might have been enough, but 3.5 cubic feet would give a margin.

Just after the greensand system, I suggested, could be a backwash carbon filter to mop up any residual taste and odor.

As a last item, I suggested a five-stage reverse osmosis (RO) filter for drinking/ cooking water. Install it in the kitchen, I told the caller, and it can also supply pure water to the refrigerator ice maker/water chiller. “It is a must when the source water is this bad, whatever we do to treat the whole-house water,” I said.

Caller in a hurry
“OK, OK, OK, just list everything, what you think I need, I will wire you the money later today, and make sure you ship right away,” he told me. “Time and tide wait for no man, or something to that effect, that I learned in high school English.”

We are cautious, because we have been at this for a while, and the buyer must return a signed invoice before we accept the order. It says: “We the buyer understand the utility and application of the equipment and accept the terms including the sale being final.”

The signed invoice and payment arrived shortly and we assembled the lot for airfreight to Japan.

A happy customer
The set of equipment featured a 3.5 cubic-foot greensand unit that was installed and produced results that were quite satisfactory. We were told that the doctor’s family of six especially liked the RO water — they said green tea, coffee and all cooked foods never tasted as good.

The fast-speaking Japanese water company president was equally pleased about his hometown hero Daisuke facing up well to US major league batters. From the sound of it, the doctor may someday become his father-in-law.

---

Sato Iwasa, Ph.D., is president of Crystal Pure Water Co., Harvard, MA. Founded in 1984, the company sells and delivers major US name-brand water purification equipment. For information, visit www.purewaterexpress.com, call (978) 456-8372, or e-mail: sales@purewaterexpress.com.