Liberty Lake Sewer and Water District is known for its pristine water that comes directly from an underground aquifer and is delivered to consumers with no extra additive treatments. LLSWD has a laboratory that monitors water quality through the system by taking 20 to 30 samples each month to ensure bacteria does not enter the system. When one of the tests came back positive for E. coli, LLSWD immediately implemented a series of daily flushing and chlorinating efforts with a boil water advisory in effect for seven days that had people on edge for the upcoming Thanksgiving festivities.
LLSWD was able to identify three dead-end lines that were not adequately being flushed through daily use, giving rise to E. coli. Liberty Lake is one of the few public water systems in the region, and for that matter the country, that does not chlorinate.
“Discovering the E. coli was a huge hit for us; it affected our morale. We pride ourselves on the purity of our water so we needed to resolve the situation ASAP,” says Mike “Andre” West, chief operator at LLSWD. The alternative was enforced chlorination by the Washington Department of Health that administers the Safe Drinking Water Act.
Hydro-Guard installations
LLSWD installed three custom engineered Hydro-Guard 100 Series automatic flushing systems with water quality sampling stations by Mueller. The installation of the units took one day using three LLSWD field personnel. Once installed, LLSWD was able to immediately program automatic flushing of the connected water mains to ensure freshwater was flushing the dead-end lines weekly. The Hydro-Guard system can flush over 110 psi, and the water is discharged to the atmosphere through a vented shield preventing erosion.
Each unit has an integrated programmer module that can be accessed by smartphone via Bluetooth. “I love the fact that I can just drive up with my phone and pull up the app to set the programmer,” West says.
All sorts of debris can slip into a water system. “One time we got a rock that jammed up in the globe control valve that can handle sand and other debris up to 5/8 inch. We had to disassemble the Hydro-Guard, retrieve the rock and put it all back together. It’s really easy to access the inner workings of the Hydro-Guard and does not take long to get in and out,” says West. If the debris problem persisted, a permanent solution would be the addition of a Singer strainer upstream from the Hydro-Guard units.
The sampling stations are tapped into the service piping no more than 18 inches from the utility’s HG-3 flushing units. This positioning is essential to allow for a sample to be an accurate representation of the utility’s water quality at the point of entry into the flushing device.
During the E. coli event, LLSWD ran 240 samples through the entire district to ensure the system was clean. “The requirement is five clean samples over two consecutive days, so we went well above and beyond to assure ourselves and residents that the system was now clean,” West says.
They got the all-clear from the Department of Health the day before Thanksgiving, so all residents could celebrate and give thanks to LLSWD staff for working so hard to restore the purity of their drinking water.
Mueller is a leading manufacturer and marketer of products and services used in the transmission, distribution and measurement of water. The company helps municipalities increase operational efficiencies, improve customer service and prioritize capital spending.
800-423-1323 | www.muellerwaterproducts.com
