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About Water Treatment


Water from the wellfield is safe to drink without treatment. However, it is relatively high in iron and manganese. Neither poses any health risk, but they can cause the water to be discolored and can affect the taste of the water.

To remove the iron, manganese and other compounds that may be present, chlorine is added to the water as it comes into the treatment plant.  Chlorine reacts with iron and manganese to form clumps or “floc” which are then removed by filtering through sand and anthracite coal filters. Polymer is added to improve the efficiency of the filters.

The filtered water is treated with sodium hydroxide to raise the pH, which minimizes the
leaching of lead and copper from household plumbing. Enough chlorine is added at the head of the plant to provide approximately one part per million (ppm) of residual chlorine after treatment.
Water from the springs is chlorinated, but is not filtered or treated in any other manner.

Monitoring the System
The City of Newberg routinely monitors for contaminants in your drinking water according to federal and state laws. Bacteriological tests are run on samples from throughout the distribution system each week. Other required testing is done quarterly, annually or every 3-9 years. All required testing is performed by independent, certified laboratories using EPA approved methods.

What tests are run on the water?

A variety of tests are done on a routine basis at the water treatment plant to monitor and control the treatment process. These include turbidity,conductivity, pH, iron concentration, temperature, and chlorine residual. Similar testing is done on the springs each week.

Samples are taken from 22 sites throughout the distribution system each week and tested for coliform bacteria. The wellfield and each spring is tested annually for nitrates. Testing for trihalomethanes and haloacetic acids, which are byproducts of the disinfection process is done annually.

Originally samples were collected from some residential taps and tested for lead and copper annually for five years. Because those samples have met the standards, testing is now done every three years. Every three years testing is also done for volatile organic compounds, synthetic organic compounds, and arsenic. Other metals and inorganic compounds are monitored every nine years. Radiological contaminants (e.g. uranium and radium) are tested at a frequency of three to nine years depending on the levels detected at each source.

All required testing is done by independent, certified laboratories.

Process control testing is done by City staff.

Test results are summarized in the annual Water Quality Report.


EPA Statement on Chromium-6 in Drinking Water

WASHINGTON – EPA issued the following statement and background information in response to a study released on December 20, 2010 by the Environmental Working Group:

“EPA absolutely has a drinking water standard for total chromium, which includes chromium-6 (also known as Hexavalent Chromium), and we require water systems to test for it. This standard is based on the best available science and is enforceable by law. Ensuring safe drinking water for all Americans is a top priority for EPA. The agency regularly re-evaluates drinking water standards and, based on new science on chromium-6, had already begun a rigorous and comprehensive review of its health effects. In September, we released a draft of that scientific review for public comment. When this human health assessment is finalized in 2011, EPA will carefully review the conclusions and consider all relevant information, including the Environmental Working Group’s study, to determine if a new standard needs to be set.”

Currently, the total chromium standard is 0.1 mg/L (100 parts per billion).
Our latest data shows no U.S. utilities are in violation of the standard.

More information on chromium: