It has been almost one month since we were in Orlando for the Water Quality Assn. Convention & Exposition, and we keep thinking back to our...
Teachers and students in Kipnuk, Alaska, enjoy the best-tasting water in the nation, according to the National Rural Water Association (NRWA). What’s their secret? The school, which gets its water from rainwater and surface sources, uses a Fyne membrane filtration system from Aquious – PCI Membranes Systems, Inc. (Milford, Ohio) to treat its drinking water.
The Fyne process has become the water treatment technology of choice for rural communities that get their water from organic-laden surface sources like lakes or rivers. Nanofiltration membranes reject undesired dissolved organic materials (mostly humic and fulvic acids) that, after chlorination, yield undesired disinfection byproducts like trihalomethanes (TTHM) and haloacetic acid (HHA(5)). The membrane system also reduces undesirable levels of iron and other metals, which may be found in these types of surface water. In addition, the membranes hold back waterborne pathogens, microbes and viruses.
Surface water near Kipnuk averages 8 milligrams of organic content per liter; however, since it is used to supplement rain catchment, the actual amount of organic matter in the water varies widely over time. The Fyne process, which uses proprietary half-inch tubular membranes that resist blinding, is ideal for this type of filtration. The tubular membranes require minimal prefiltration and can be kept clean by periodically passing a foam ball down the length of the tubes. This makes them much less costly to operate and maintain than spiral membranes, which require upstream prefilters to remove suspended solids down to 10 microns, and frequent chemical cleaning.
The units used by the Kipnuk school (and two others in Kongiganak and Kwigillingok) are small even by Fyne standards, processing just 1.1 gal per minute. After being processed, the water at the schools meets or exceeds standards for drinking water for TTHM (<80 µg/L) and HAA(5) (<60 µg/L). Turbidity levels are typically below 0.1 NTU. Standards require <0.3 NTU. The systems are simple and automated enough to allow unattended operation, with intervention on no more than a weekly basis for routine operation and maintenance. The systems can be monitored continuously and remotely through an Internet connection.
The NRWA selected Lower Kushkokwim School District (LKSD) in Bethel, Alaska, which operates the school in Kipnuk, as the winner of the 6th Annual Great American Water Taste Test, held in Washington, D.C. LKSD competed against the top water systems from 48 state rural water associations to take this honor.
Several of the schools in the LKSD have independent drinking water systems and, before the Fyne systems were installed, used rain catchment as the primary source of drinking water. The captured rainwater was coarse filtered and processed by small distillation units. Inadequate supply, and the fact that the water did not meet the standards established under the U.S. EPA’s stringent Stage 1 Disinfectants and Disinfection Byproducts Rule, meant that a new system was needed. Greg Jones, president of GV Jones and Associates and engineer for LKSD’s water treatment projects, recommended the Fyne process for the school’s filtration needs.
As noted previously, Kongiganak and Kwigillingok also currently use Fyne systems to produce potable water for students and teachers, and two other schools in the district are using Aquious – PCI Membrane systems for groundwater filtration.
Just getting the Fyne units to their destinations was a challenge. Located in remote western Alaska, about 100 miles southwest of the city of Bethel, Kipnuk is one of 27 schools in 23 traditional Yup’ik Eskimo communities that make up the LKSD. Based in Bethel, the LKSD serves an area roughly equivalent to the size of West Virginia. The district has 3,800 students, mostly of Yup’ik descent, and 352 teachers. Many teachers live in homes located on the school grounds. Due to the numerous ponds and marsh-like areas in this part of Alaska, there are few roads outside of Bethel, and most travel in the Lower Kuskokwim District is done by plane. Land travel is only possible during the winter when the tundra and its lakes are frozen.
The Fyne units were packaged in 20-ft steel shipping/cargo containers that were completely fitted out so they could house the units permanently once they arrived on site. They shipped from Bellingham, Wash., to Bethel aboard ocean-going barges. At Bethel, they were trans-shipped onto smaller barges and towed down the Kushkokwim River to be landed on the beaches near Kipnuk and the other communities.
“The orders were placed in July with the understanding that they must make it to Alaska before mid-September so they could be landed on the beach before the ocean froze,” said David Pearson, general manager of Aquious – PCI Membrane Systems. “Once they arrived, they had to wait until the winter freeze before being moved from the beach and hauled across the tundra to their final locations.”