Where UV water treatment falls short

By Marc Daubitz

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While I applaud the idea of the city of Cedar Rapids bettering itself, I also believe some very notable consequences and misconceptions associated with this latest water plant upgrade project need to be more clearly addressed.

The main hero of this new plant is the ultraviolet (UV) light disinfection system, but ultraviolet light disinfection is best suited for end-user systems rather than at the treatment plant. After the water leaves a water plant, it is subject to leaks in the system, cracks in the plumbing and water main breaks that can allow microorganisms into the water supply.

What's more, this UV treatment has no residual value, requiring the city to continue with the heavy use of chlorine and chloramines in the treated water.

Ultimately, normal operation and contamination seen in water infrastructure render such a large expensive system ineffectual after the water leaves the treatment plant.

And that expense is well worth noting.

The aftershock of this system's price tag will reverberate right into homeowners' wallets. Per the Water Department, water bills have increased from $15.55 to $25.65 monthly - a more than 60 percent increase in five years.

More disturbing is the fact that this upward trend does not take into account future maintenance costs, as these light systems will undoubtedly need repair or replacement.

Lastly, statements made in a Dec. 19 newspaper story about the city's hard water treatment need to be clarified. While slaked lime is added to reduce the hardness of the water (as reported in the article), soft water is defined as water with less than 1 grain, 17.1 ppm, of hardness. Cedar Rapids water routinely averages 8 to 10 grains hard.

Recently at the Master Plumbers class taught at Kirkwood Community College, the water was tested at 11 grains hard, which is considered extremely hard. So, while the city water is “less hard” as a result of this lime, it is by no means soft and still has a pound of dissolved rock in every 700 gallons of water.

In conclusion, improved water treatment and increased water quality is often better achieved by treating the water at the home rather than treating at the city plant level.

Furthermore, that cost of better quality water can often be lower by treating it at the point of use, in the home, rather than treating it at the city level when considering that 90 percent of water pumped by the city is used for industrial purposes.

Marc Daubitz is president of Culligan of Marion. Comments: md_wpculligan@ccr.net