Instead of tens of thousands of gallons of water spurting out onto Sumner Avenue to be swallowed up by nearby storm drains, yesterday morning’s 15-minute process let out just a dribble of water that district workers used to test quality.
“In a time of such water shortage, people really don’t understand seeing water doing down the drain,” said district special projects engineer Melanie Schumacher.
Soquel Creek Water District leaders are looking at purchasing a new piece of water main-flushing technology as one of several potential water-saving projects that they could fund through fees paid by new district development permits. The district board of trustees also spoke about using fees to fund turf replacement efforts and a small satellite water reclamation plant.
While a typical water main flushing can waste about 22,500 gallons of water, all but about 150 gallons emptied from water hoses at the end of the job are conserved, said Chris Wilkinson, president of Neutral Output Discharge Elimination System. By linking together two fire hydrants via a pump, oversized firehose and elaborate filtering system mounted atop a flatbed truck, the onrushing water is filtered, cleaned and returned to the district’s water pipes.
Water main flushing helps water utilities to scour out pipe buildup through high-pressure flow, maintaining the water’s high quality through coloration, odor and material content, officials say. Standard best practices call for the flushing to occur once a year, but Soquel Creek Water District has mostly suspended the practice in recent years, as in many other areas, due to water conservation concerns.
Monday’s demonstration by the New Mexico-based company, which goes by the name NO-DES, was at least the third time since 2011 that the water district has taken a close look at Wilkinson’s unique water-saving technique. Were district leaders to go further with the process at the July 21 meeting, they would have the option to purchase the system and its truck for about $365,000, said Schumacher. Other California cities already on board with the process include San Jose and Hillsborough. Soquel Creek Water District, prior to suspending flushing except for case-by-case health and safety needs, typically used from 2.6 million to 3.9 million gallons of water a year to flush its water mains, Schumacher said.
The Neutral Output Discharge Elimination Systems typically pay for themselves in water savings in about two and a half years, not an argument that can be made for many pieces of heavy equipment, Wilkinson said.
Monday’s district tests of the flushing were designed to clarify several issues, including comparing what is in the drinking water before and after its cleaning, and the toxin concentration level collected on system microfilter bags, which could affect later disposal, said Christine Mead, district operations and maintenance manager.
©2015 the Santa Cruz Sentinel (Scotts Valley, Calif.) Distributed by Tribune Content Agency, LLC.
