The Miawpukek Mi'kamawey Mawi'omi First Nation community (Micmac Band) at Conne River on the south coast of Newfoundland has contracted for the installation of a new membrane filtration plant.
Designed by PCI Membrane Systems, Inc., Milford, OH, to produce 1.3 million liters/day (MLD) of clean drinking water, the plant will use proprietary membrane filtration technology to remove organic materials from surface water prior to chlorination. The filtration system will allow the community to meet current Canadian Drinking Water Guidelines and much stricter standards expected in the next 10 years.
"The Conne River Micmac Band currently get their drinking water from a surface source located in the Southwest Pond watershed," said Eric Humphries of Design Management Group Ltd. (DMG), the Band's engineering consultant. "This current supply is treated by chlorination only and there have been serious concerns about this form of treatment."
Brian Kelly is Director of Capital Projects at Conne River, reporting directly to the Chief of Council for the community, and has overall responsibility for the project. He provides the background: "We really promote good health practices within our community and a high-quality water supply has to be a priority.
"We built a new water and sewer system, including a new dam and sewage lagoon, about 10 years ago," he said. "But we've started to see problems with chlorination byproducts. Also, for about the last five years we've been under a boil order. Most of the homeowners have to buy bottled water for almost everything. Washing is about the only thing that domestic water can be used for."
Consultant DMG determined that the Fyne Process offered by PCI Membrane will be immediately effective in providing high-quality potable water to Conne River residents. The process exceeds current parameters and includes provisions to meet future needs, which might include the construction of a fish processing operation. With this and other possibilities in mind, the Fyne plant will be built to allow for expansion to 1.6 MLD.
An alternative to chemical-based processes for removing organic materials, the Fyne Process offers several advantages. No chemicals are added to the water prior to chlorination and there is no residual chemical sludge to dispose of. Savings on chemical purchases and sewage-disposal costs quickly outweigh the marginally higher system price. In addition, the Fyne Process membranes provide a physical barrier that holds back waterborne pathogens, microbes and viruses, as well as reducing undesirable levels of iron and other metals, which may also be found in surface water.
The Conne River facility will be the first Fyne Process installation to use spiral nanofiltration membranes rather than the tubular membranes used at earlier Canadian projects, which involved smaller water volumes. These projects included plants installed at First Nation communities at Chapel Island, Nova Scotia, and at Middle River, British Columbia. The spiral membranes are much more economical for handling the high water volumes at Conne River.
The Fyne Process is based on nanofiltration. Surface water is prefiltered to remove suspended solids down to 10 microns. This pre-filtered raw water, which still contains large quantities of organic compounds, is then passed, under high pressure, through a series of membrane modules. A fraction of the feed water passes through the membrane, which holds back the disinfection byproduct precursors, along with iron and other undesirable metals, and waterborne oocysts, bacteria and viruses. The undesirable components are automatically flushed from the system with unused feed water and returned to the river.
The clean water that has passed through the membrane (the filtrate), can then be safely chlorinated and delivered to the potable water distribution system. After treatment, it is effectively colorless (even if the raw feed water color is 200° TCU or even higher) and has exceptionally low disinfection-byproduct levels, as evidenced by TTHM levels well below 100 mg/l.
The Fyne plant operates automatically, with very little supervision. In fact, the system can be monitored continuously and remotely through an outside telephone line. Minimal routine maintenance includes bi-weekly cleaning of the spiral membranes using pre-filtered feed water and detergent (similar to common household laundry soap). No other chemicals are used, so there are no storage or disposal issues. After cleaning, membrane wash water is stored on site and metered back into the river in accordance with strict environmental standards.
