A Switch from Wells to Municipal Water Treatment Brings Residents of a Rural North Dakota County Safe, Fresh-Tasting Water All Year Round

For the residents of Emmons County, North Dakota, a rural community of 3,550 approximately 50 miles from Bismarck, water from artesian wells that had poor taste and caused rust and corrosion on their fixtures and appliances was an accepted way of life. That ended in May 2012 when a new municipal water treatment plant was completed to treat water drawn from the nearby Missouri River. A reliable supply of clean and fresh-tasting drinking water is now the new normal.

Made possible with funding from the American Reinvestment & Recovery Act, and designed and installed by H20 Innovation Inc. (USA), the new plant relies on a unique filtration system that combines ozone pre-treatment for removal of organics; DOW Ultrafiltration membranes to remove pathogens and solids down to the .03 micron level; and DOW FILMTEC Reverse Osmosis membranes, which provide salinity, additional taste and odour removal.

“Many communities like to treat water with ozone because it can be economical, effective and has no by-products except oxygen and water but the downside is a harsh inlet stream for further treatments” said Bill Gladitsch, North American commercial manager for Dow Water & Process Solutions. “Emmons County chose our ultrafiltration modules because they maintain integrity even in harsh environments. The modules passed a daily integrity test with no fibre breakage demonstrating excellent ozone resistance.”

Putting the system to the ultimate test, discharge limits at the Emmons County plant have prevented routine chemical cleaning of the filters, which is designed to reduce fouling and restore and maintain flux and permeability. Despite this, DOW Ultrafiltration and DOW FILMTEC RO systems have met all integrity tests and flow requirements while maintaining water quality standards for reliable drinking water.

“We are extremely gratified to report that after five months, by all measures – permeability, pressure and fibre integrity – the Dow Ultrafiltration filters are maintaining their integrity and drinking water values are holding steady, even under these unusually tough conditions,” said Doug Neibauer, Executive Director of South Central Regional Water District.

“There are many towns, cities and counties across the U.S. that are facing water quality challenges similar to Emmons County. Finding an economic solution that is reliable and effective is a top priority,” said Scott Sedey, Project Manager of H20 Innovation. “The safety and reliability of UF and RO filtration answers their performance needs and is within financial reach. We anticipate seeing these systems sprout up in many more communities in the future.”

Dow’s ultrafiltration technology is based on technically advanced H-PVDF hollow fibre with uniform pore size that maintains high performance under a wide range of feed water conditions. Systems designed with Dow Ultrafiltration use an outside-in flow configuration which allows for less plugging, higher solids loading, higher flow area and easy cleaning.