Detective H2O

Detective H2O: The Case of Misdiagnosis

By James McDonald, PE, CWT

Check out the audio dramatization here.

The birds chirped cheerily as the sun shone brightly through the streaked office windows of Herbert Henry Oxidane, P.I., CWT. Detective H2O squinted out the window, uncomfortably. “I don’t like it,” he mumbled to himself. “Everything is so bright, it’s hard to see what’s going on out there. I’ll take a good drizzle any day of the week.”

The first clap of thunder and the black, mid-twentieth-century phone both announced themselves at the same time. On the third ring, the water detective answered the phone, “Detective H2O here. The best water treater this side of the Ohio, solving water problems drop by drop. Whatcha got?"

“Mr. Oxidane, this is Misty Downs, from Widgets B Us. You might not remember me, but we met a year ago when you inspected our watertube boilers.”

Detective H2O remembered Misty, alright. He couldn’t forget that sweet smell of lemon verbena perfume.  He had worked shoulder to shoulder with her as they climbed through three watertube boilers during the summer plant shutdown. 

“Uh, yes, I remember you…inspection…watertube boilers. You passed…I mean your boilers passed with flying colors.”

“Yes,” she beamed, “that was us! We need you again, but this time for our cooling towers. We’re having problems with our microbiological control feed program. Something is not up to snuff about it, but we don’t know what. Can you fit us into your busy schedule, Mr. Oxidane?”

“Let me check my calendar,” said Detective H2O as he ran his finger down the empty page. “Oh, yes, I happen to have an opening this morning. I can be there within the hour.  Will that work?”

“Of course, Mr. Oxidane. I look forward to seeing you in an hour.”

*   *   *

Detective H2O cracked a crooked smile as the rain started during his drive to Widgets B Us in his old Ford. He was looking forward to this visit. 

Making his way beyond the guard shack, he headed straight to the Powerhouse. Misty Downs was just inside the door silhouetted by a burst of steam from a recent boiler blowdown to the drain. Arms on her hips as he walked towards her, she exclaimed, “Mr. Oxidane, I’m so happy you’re here! Follow me!”

Putting up no resistance, the water detective gladly obeyed. When they reached the water testing station, Misty said, “Look at this, Mr. Oxidane. The Free Chlorine levels have taken a dive! Right out of the blue! All of a sudden for the last three shifts! We don’t know what’s going on! We’ve turned up the bleach pumps, but no luck! Now, I’m smart enough to know there are two sides to the oxidation coin. One side is demand. The other side is residual. You can’t have a Free Chlorine residual until you’ve met demand. We’ve been racking our brains, see. Is there process contamination? Perhaps oil leaking into the system causing an increased demand? I guess on the flip side, are those little microbiological critters multiplying at such a rate that we just can’t keep up with demand? We just don’t know, Mr. Oxidane. We just don’t know!”

The water detective scratched his chin, as he thought. “Let’s take this one step at a time, Misty. What you say is correct, but let’s start from the beginning. Can you get me a sample of the cooling tower water? We need to run some tests.”

“Sure,” replied Misty. A moment later, she was back with sample in hand.

Detective H2O started his barrage of testing, beginning with the Free Chlorine test. It was completely colorless, but his sharp, well-trained eye did catch something immediately. He moved on to the rest of the testing, including Total Hardness, Total Alkalinity, Conductivity, pH, and tracer. “This is interesting,” he said. “Can you take me to the sodium hypochlorite feed station and cooling tower basin, please?”

“Of course! Have you found anything, Mr. Oxidane?” Misty asked.

“Maybe.”

When they arrive at the sodium hypochlorite feed station, the water detective noted the pulsing of the dosage pump and its tubing. With a flooded suction, priming did not appear to be an issue at this point. The pump was pumping to beat the band.  Moving on to the cooling tower, he noted a fine white foam covering parts of the sump’s water surface. Some of it got caught up and flew out the top fan as he took a peek inside the cooling tower plenum area.

Detective H2O then lead Misty back to the sodium hypochlorite feed pump, which he swiftly turned off. With her mouth open, Misty asked, “Why did you do that? We don’t even have a Free Chlorine residual, and you’re turning it off? Don’t we need more bleach instead of less?”

The water detective took a moment to enjoy the perplexed look on Misty’s face before revealing his hand: a full house. A little crease formed between her eyes when she was perplexed.

“You do have a good understanding of the basics of oxidizing biocides, Misty, but I believe you were blinded by the light on this one. Let me show you.”

The water detective lead her back to the water testing station, poured the cooling tower water sample into a sample vial, and said, “Now watch what happens when I place the Free Chorine test reagent powder into this sample.”

“It’s just clear, Mr. Oxidane. That means no Free Chlorine.”

“No, watch again,” said Detective H2O as he rinsed and repoured the sample. “Come closer. Watch the very beginning right when the reagent first touches the water sample.” 

As Misty and Detective H2O stood cheek to cheek watching the Free Chlorine test reagent powder drop into the water sample, it happened.

“Did you see that, Misty?”

“Yes, I did! What does it mean?”

“That flash of pink you saw as the Free Chlorine test reagent powder hits the water proves there actually IS a Free Chlorine residual in your cooling tower.”

“What? Why? How?” asked Misty in confusion.

“Did you notice the other tests I ran before? Did you notice the colors some of them changed? The Total Alkalinity test for instance.”

“Yes,” said Misty. “I did notice that one test, in particular, turned different colors than normal. Instead of a green and reddish transition, the colors were blue and yellow. I just figured you were using a test I hadn’t seen before.”

“No, Misty, it’s the same Total Alkalinity reagents most every other water treater uses. Did you notice the white foam on top of the cooling tower water when we took a look inside the plenum area?”

“Yes,” Misty replied again. “I thought it was from whatever the contamination is. What’s going on here, Mr. Oxidane.”

Regretfully bringing his consulting services to a near close, Detective H2O finally revealed his complete hand. “It’s quite simple, actually. You’re overfeeding your sodium hypochlorite. When this happens, it can bleach out the water analysis tests, giving suspect or erroneous results. The Free Chlorine levels are so high that they are bleaching out the Free Chlorine test almost immediately, but when you watch closely as the test reagent powder hits the water, you can see a flash of pink. That’s the reagent doing its job just before it fades from the high sodium hypochlorite levels. Also, the Total Alkalinity test turned blue and yellow because of the sodium hypochlorite overfeed. The tracer test was affected as well, so I suspect you may be overfeeding your inhibitor product too. Lastly, that white foam we saw on the cooling tower water was, once again, from the sodium hypochlorite overfeed. That’s why I turned off the oxidizing biocide pump.”

Seeing her disbelieving look, the water detective took the cooling tower water sample, prepared a dilution, and ran the Free Chlorine test again. A beautiful pink color bloomed in the sample.

“See,” he said, “once we properly dilute the sample, the Free Chlorine residual is clear as day.”

Smiling broadly, Misty gave the water detective a big hug. “Thank you, Mr. Oxidane…or should I say Detective H2O. You saved the day. You’re our hero!”

For once, the water detective was speechless as his face turned the rosy pink of a Free Chlorine test.

*   *   *

In the underbelly and penthouses of the metropolis of Waterville, where the boilers percolate and cooling towers fog, there is one man who works tirelessly to end corrosion, stop scale, fight lowlife microbes, and conserve water. That man is Detective H2O. Best water treater this side of the Ohio. Solving water problems drop by drop.