Science of safe drinking water

OP Ed By Scott Fernandez Master of Science in Biology,  M.Sc.


Why Shouldn’t Portland Have Safe Drinking Water?

The answer is easy: we can if we retain our open reservoirs because of the profound public health benefits they generate. The Portland open reservoirs have provided safe and healthy drinking water for over 100 years.

A covered reservoir system in Portland can lower drinking water quality with toxic chemicals and disinfection byproducts. The new covered reservoir at Powell Butte 2 has already leaked millions of gallons of water per week. Poor construction and leaks from that covered reservoir can add to the uncertainty of drinking water quality.

EPA says “science will determine the ultimate outcome” of EPA Long Term 2 Enhanced Surface Water Treatment Rule (LT2).

Good news for Portland water users. In the coming weeks a new and stronger scientifically supported public health argument for an EPA LT2 open reservoir waiver will soon be available for the public to review at

The EPA has two more years to review LT2 and make a decision to keep the open reservoirs in Portland. For years citizens of Portland have asked for a waiver from the EPA LT2 regulation to keep their open reservoirs. They were left with only a tepid response from City of Portland.

In contrast to Portland, New York City elected officials and the New York Congressional delegation have soundly supported their Hillview open reservoir waiver putting forth a robust effort for many years to retain it as is. Why aren’t our officials doing what the New York Congressional and New York City elected representatives are currently pursuing to keep their open reservoir?

While EPA and New York are still reviewing the Long Term 2 Enhanced Surface Water Treatment Rule for alternative actions to keep their reservoir open, Portland City Council is about to unnecessarily destroy many trees and meaningful portions of our Mount Tabor and Washington Park Reservoirs Historic Districts.

If we are forced to rely on a closed drinking water system made up of only covered reservoirs we will lose the public health benefits of open reservoirs. One important negative water quality effect in a covered reservoir system is the process of ammonia disinfectant breakdown to nitrogen. The result is unwanted nitrification and public health risk.

“Consequently, nitrification episodes in distribution systems occur in the dark (in covered reservoirs, pipelines, taps, etc.)”  EPA 2002

Open reservoirs provide sunlight and

• inhibit microbial break down of the nitrogen originating from the ammonia disinfectant thus stopping nitrification

• break down unwanted nitrogen-based byproducts such as nitrites, nitrates, nitrosamines, NDMA, sodium nitrites, and sodium nitrates, originating from chemical reactions in the distribution pipelines.

• the chemicals are linked to diabetes, harmful liver effects, anemia, etc.

The everyday use of ammonia as a supporting disinfectant to chlorine is necessary and helpful to maintain public health. However prolonged neglect of the deferred water distribution system maintenance over the last decade, such as routine flushing programs, has allowed biofilm and accumulated sediments to become problematic (City of Portland Auditors report).

The impact of poor maintenance, as seen last year when Portland had fecal microorganisms throughout the system that can harbor in biofilm and sediments. Biofilms and sediments can negatively impact our primary disinfectant chloramine and increase chlorine demand freeing ammonia. Thus creating the primary substrate for nitrification resulting water quality decline.

The City auditor’s report showed that thousands of hours of drinking water system deferred maintenance was neglected.

A recent Portland Water Bureau excuse for deferred maintenance was the Big Pipe construction. That rationale makes no sense because one side of town could have easily been routinely maintained while the Big Pipe on other side of town was being built.

Open reservoirs don’t create nitrification, they inhibit it. Sunlight inhibits microbial activity that would otherwise generate unwanted nitrites and nitrates. Sunlight also breaks down unwanted chemicals such as carcinogenic NDMA and others.

Please act now to save Portland open reservoirs and our public health. Call your elected officials today.

We’re building on the new way of thinking that reduced environmental chemical exposure is the new future of open reservoirs.

It’s not too late.


Science of safe drinking water

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