Published: Jun 28, 2013 | 21:09 PM

Portion of Irvine Lake Pipeline Converted to Recycled Water Use

10 Agricultural Customers Affected

In June, Irvine Ranch Water District agricultural customers who had been served with irrigation water from the Irvine Lake Pipeline began receiving treated recycled water. Projected recycled water demand by the converted customers is approximately 1,800 acre feet per year, replacing the imported water source serving Irvine Lake.

“Our growers have been successfully utilizing recycled water for crops and orchards for a long time, so when IRWD approached us about the conversion of more sites to recycled water, it made sense,” said Peter Changala of The Irvine Company. “We provided staff to work with IRWD and when the changeover to recycled water happened, it was seamless. Implementing this conversion will not only mean increased water reliability for our farmers, but will improve potable water supplies for the region.”

IRWD conducted more than two years of research and cooperation between the impacted customers, many departments within IRWD, and outside regulatory agencies to implement the project.  In August 2008, IRWD began working with agricultural customers and commercial nurseries located along Portola Parkway to bring their irrigation systems into compliance for recycled water use.  Up until that time, those customers were using water from the Irvine Lake Pipeline for irrigation. Irvine Lake is supplied with untreated water purchased from Metropolitan Water District of Southern California, as well as native runoff water.

Once the IRWD On-Site Systems Group was directed to proceed, the team members began the lengthy process of contacting customers and conducting system investigation. What they found when examining several customer sites was a web of underground pipes.

“A large-scale water retrofit like this is complicated because pipes have been in the ground for many years and often plans for those facilities do not exist, limiting our ability to determine with certainty where pipes are located or how they may be connected,” said Mark Tettemer of IRWD Water Resources. “Under these circumstances, IRWD makes observations, runs tests, obtains whatever plans or schematics may be available and conducts interviews with employees of the customer to determine the best possible information regarding what’s happening underground.”

IRWD found that properties served by the Irvine Lake Pipeline were vast, complex water systems that went beyond agricultural or nursery irrigation, to serving commercial buildings and even homes. Nursery irrigation systems operated differently than agricultural crop irrigation adding a layer of technical complexity to an already complex evaluation.

It was a Learning Process

The On-Site Group called on the expertise of the IRWD Cross-Connection team and Water Quality Department, the Department of Public Health, Orange County Health Care Agency and the Regional Water Quality Control Board for assistance.  Their joint conclusions determined that several properties would have to install new drinking water lines while others would need to reconfigure plumbing systems to meet compliance requirements.

As these evaluations progressed, the economy took a toll on the commercial nurseries, and they closed down and vacated some of the land which was to be converted.  This had the effect of simplifying some technical aspects with irrigation systems left unused, but added the issue of initiating contact with new customers.

As the technical and customer issues were slowly resolved, IRWD staff focused on high level priorities to ensure that no cross-connections existed. Where customers required drinking water, new lines were installed and inspected; critical plumbing changes to recycled water lines were constructed and approved.  As compliance issues were nearing completion, On-Site conducted final system tests and in-field consultations with the regulatory agencies. With conversion in sight, On-Site requested that IRWD Operations “flip the switch” to recycled water, and on June 8, the new source was successfully connected.

Please visit the IRWD website for more information about IRWD Recycled Water