Environment
4:39 pm
Tue July 8, 2014

In Clovis, Purple Pipes Give Recycled Water New Life

Purple signs explain recycled water irrigation at Pasa Tiempo Park
Purple signs explain recycled water irrigation at Pasa Tiempo Park
Credit Kerry Klein

This is Pasa Tiempo Park in Clovis.  It’s 5 acres of green grass tucked between suburban homes and an orange grove.  It’s a lot like any other neighborhood park:  benches, fruit trees, and lots of space for kids.

Aller: I love the playground features, we have like spider-web crawlers and we’ve got some of the rope climbing things.  My name is Eric Aller, and I’m the parks manager for the city of Clovis.

And, like in any other park, sprinklers keep the grass green.  But one thing sets Pasa Tiempo apart.  Water in the sprinklers comes from the sewer.  But you’d never know it.

Aller: It looks like normal water, and it smells like normal water, and the plants respond to it like normal water. It’s basically just good ol’ water.

Many facilities in Fresno and Clovis clean wastewater—that’s water from washing machines, the kitchen sink, and yes, even toilets.  But Clovis is alone in how highly it treats the water, and how much it reuses.  Its recycled water is sent not only to Pasa Tiempo Park, but to patches of grass along roads and traffic islands.  And there are more plans for the future.

So how does recycled water get to Pasa Tiempo Park?  The short answer is purple pipes. 

Klein: How purple is it?

Aller: It’s not a deep deep purple, but it’s purple.  It’s just about as purple as purple can be.

You don’t actually see the pipes.  They’re all underground.  But along big roads like Temperance and Barstow, little purple signs explain what’s happening below the surface.

You can shower in it, you can use it to swim in, you can use it to irrigate food crops, you can use it for virtually everything except for drinking.

But how does water get from your washing machine to the purple pipes?  When it empties, that water joins all the other water circulating in sewers under Fresno and Clovis.

If it reaches the Clovis Water Reuse Facility, it goes through 3 major rounds of cleaning: after solid particles are sifted out, it enters something called a membrane bioreactor, a series of bristles that filter the water through.  The next step is my favorite: the Cannibal process, where bacteria eat the nasty stuff in the water, then eat each other.  Lastly, disinfection:  UV light bulbs inactivate any leftover bacteria. 

But just how clean is it?  I sat down with Lisa Koehn with the Clovis Public Utilities Department.

Koehn: You can shower in it, you can use it to swim in, you can use it to irrigate food crops, you can use it for virtually everything except for drinking.

A purple lid covers recycled water sprinkler valves at Clovis Community Medical Center
A purple lid covers recycled water sprinkler valves at Clovis Community Medical Center
Credit Kerry Klein

This is cleaner than most wastewater ever gets.  But that no drinking part is a big deal.  Purple pipes are kept completely separate from drinking water.  They go nowhere near homes.  And they won’t for a long time.

Now membrane bioreactors sound pretty cool—but what do they look like?

Klein: If I were your neighbor and I were to look out my window, would I see gushing water and fizzing and bubbling water anywhere along this property?

Koehn: No, the site is pretty dry. If you were to drive by it or live near it I doubt that you would have a clue what’s going on inside the facility.

Everything’s underground, and behind cement walls.  The only sounds are generators.  The only smell, grass.  The one give-away, though, is the storage tank that holds 3 million gallons of water.  Enough to fill 150 or 200 swimming pools.

That’s how much water the facility treats every day.  And as Clovis grows over the next few decades, Koehn says they plan to triple the facility’s capacity.

Increasingly we’re seeing communities realize what an asset this water is. That it's not waste.

Heather Cooley, a water expert at the Pacific Institute in San Francisco, tells me that recycling addresses the two biggest water issues facing California: supply and quality.  It’s a source of water that’ll always be there.  And she says she’s seeing a lot of momentum when it comes to water recycling.

Cooley: Increasingly we’re seeing communities realize what an asset this water is. That it’s not waste, but there are resources.

Pasa Tiempo is just the beginning of purple pipes in the valley.  Clovis is also working with the local hospital and CalTrans to satisfy their needs with recycled water.  The city of Fresno also plans to start installing purple pipes in the next few years.

Soon, Clovis Community Medical Center will be irrigating its grounds with recycled water
Soon, Clovis Community Medical Center will be irrigating its grounds with recycled water
Credit Kerry Klein

But recycling water isn’t without its challenges.  The infrastructure is expensive.  It’s energy intensive, too much to make the water drinkable.  Without that, purple pipes will never run directly to homes.  And for now, Clovis actually cleans more wastewater than it can reuse.

Despite all of these challenges, I asked Eric Aller if he thinks reusing water is worth it.

Aller: Oh yes, yes, because it’s a good source of water and if we have this available we should use it. 

Clovis has seen the future of water—it’s not blue, it’s purple.