A 400 billion gallon milestone: the GRWS water reuse project

One of the most iconic potable wastewater treatment plants in the world is celebrating 15 years of service as the Orange County Sanitation District honours the groundwater replenishment system. 

Crystal Anniversary

One of the most iconic potable wastewater treatment plants in the world is celebrating 15 years of service as the Orange County Sanitation District (OCSD) in the US honours the groundwater replenishment system (GWRS). 

Originally online back in 2008, the now infamous GWRS plant was a joint project between the OCSD and the Orange County Water District (OCWD). 

It operates using a three-step treatment process consisting of microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide.

The result is high-quality water that is pumped to recharge basins in Anaheim where it naturally percolates into the Orange County Groundwater Basin and becomes part of the drinking water supply for almost 2.5 million people in the north and central Orange County. 

To date, the plant has produced more than 400 billion gallons of water.

However, that is not all, treated water is also discharged to injection wells located along Orange County’s coast - this helps to create a seawater intrusion barrier that in turn protects groundwater supplies.

"This project provides local reliability to our region, decreases our dependence on imported water and serves as a model for the rest of the world,” said Cathy Green, OCWD Board President.

Upgrades, expansion and sustainability

OCSD said that the GWRS water has become a primary source used to refill the basin and allowed surrounding agencies to pump more water from the basin and become more locally sustainable.

From the start, the GWRS had a capacity of producing 70 million gallons of water per day (MGD). Fast forward to 2015, and that capacity has been increased to 100 MGD.

Its 15th Anniversary comes after the announcement that the plant will receive its final expansion and upgrade where the GWRS will soon recycle 100 per cent of OCSD's reclaimable flows, providing up to 130 MGD – enough to serve one million people daily. 

This multi-agency system is the world’s largest water reuse facility and an example of what can be accomplished when agencies focus on the needs of those they serve.

Chad P. Wanke, Board Chairman of OCSD, said: "The recent milestone of recycling 100 per cent of our agency’s reclaimable flows provides critical water source stability for Orange County. 

"This multi-agency system is the world’s largest water reuse facility and an example of what can be accomplished when agencies focus on the needs of those they serve.”

To mark the occasion a commemorative edition of bottled GWRS water will soon be made available. 

Tackling public perception

Key to the success of any water reuse scheme is proactive and transparent public engagement. 

Get it wrong, and it can lead to projects being stalled and even mothballed. Get it right and the utility has long-term access to a sustainable supply of water.

OCWD remains a shining example of a utility getting it right; a success Markus is keen to credit to his peers.

Previously speaking to Aquatech Online, OCWD general manager Mike Markus discussed the importance of reaching out positively to the public on this joint project. 

"We had a committee at that time," he explains. "And they were the ones that said, listen, what we need to do first and foremost before we do any engineering or anything else, is we have to develop an outreach plan. And so, we developed that outreach plan in which I played a small part."

And make sure that they were able to clearly articulate what it is that we were going to do so that we could gain the trust of the public.

Rather than hiring external consultants for the outreach, OCWD decided instead to look internally and train its own team of engineers.

"We had to take engineers who hate to talk to people and transform them, in essence," the general manager says. "And make sure that they were able to clearly articulate what it is that we were going to do so that we could gain the trust of the public. 

"We were very successful in doing that."