Libby water meets safety standards

Drinking water in the City of Libby is safe and meets state and federal water quality standards, according to the recently released Annual Drinking Water Quality Report for 2014.

The report provides the results of mandatory water testing conducted at the Libby Water Treatment Plant between Jan. 1, 2014, and Dec. 31, 2014.

“We just try our best,” said Libby plant manager Jeff Haugen. “It’s been difficult with the building of the dam, but the crew here does a good job.”

During the time period included in the report, only two violations were noted for Libby’s water system, both dating back to flooding incidents of March 2014. The violations were for excessive turbidity, or cloudiness of the water. The violations, which were ascribed to excessive runoff, were for the date of March 12, 2014, the high point of the runoff, as well as for the average turbidity of the entire month of March.

Turbidity isn’t necessarily an indicator of contamination, but it is used to measure the effectiveness of water filtration, according to the report.

The water treatment plant operators are required by law to monitor Libby’s drinking water for a number of different contaminants on an exacting schedule. The schedule, though, isn’t routine. Different contaminants are tested at different times and in varying intervals to ensure accurate representative sampling.

Libby’s water tested well under the maximum contaminant levels allowed by federal and state regu

lation for all of the contaminants measured in 2014. In addition to the turbidity monitoring, the water was tested for five separate categories of contaminants.

Total trihalomethanes, or TTHM, levels were sampled at three different points during the year. The highest level of the contaminant detected was 23 parts per billion, which is the equivalent of 23 minutes during a span of 2,000 years. The state’s established maximum contaminant level for TTHM is nearly four times greater than the highest amount detected in Libby’s water, at 80 parts per billion.

Libby’s test results also showed 29 parts per billion as the high point for haloacetic acids. The maximum contaminant level for this contaminant is 60 parts per billion. Both haloacetic acids and total trihalomethanes are by-products of the water chlorination process.

Two inorganic contaminants were also subject to testing in 2014. Nitrates and fluorides, which generally contaminate drinking water as the result of runoff or erosion or natural deposits. Nitrates registered at .04 parts per million, relative to a maximum contaminant level of 10 parts per million. Fluoride was measured at .02 parts per million, with the maximum allowable level being four.

Gross alpha is a test to measure radioactive contamination of water, which is also generally caused by the erosion of naturally-occurring sources into the water system. The maximum contaminant level allowed under Montana’s regulations is 15. Libby’s highest measurement was 2.1, well below the safety threshold for public water systems.

According to the report, the maximum contaminant levels are set to very stringent standards.

“To understand the possible health effects for many regulated constituents, a person would have to drink two liters of water every day at the maximum contaminant level for a lifetime to have a one-in-a-million chance of having the described health effect,” the report read.

The full report is available at Libby City Hall.