As Petaluma city staff continues to evaluate the three-year-old Ellis Creek Water Recycling Facility and its ability to serve the needs of the community, one area that appears to be working well is the plan to use recycled wastewater to irrigate city parks, grounds and schools starting this summer.

"The more recycled water we use in town, the less water we have to purchase from the Sonoma County Water Association," said Public Works Director Dan St. John.

Over the past five years the city has purchased between 8,000 and 10,000 acre feet of water annually from the Sonoma County Water Association to meet its drinking and irrigation needs. That adds up to between about 2.5 and 3.2 billion gallons of water each year.

Ironically, until 1976, wastewater was viewed by most municipalities as a nuisance that needed to be disposed of, which the city did primarily by releasing it into the Petaluma River. But that year, after a study showed that treated wastewater could be used to irrigate a range of crops, what had once been viewed as a scourge started to become a commodity.

Petaluma began paying several ranches and vineyards to take the wastewater since, back then, the idea of agricultural entities paying for treated wastewater — as many do today — was still foreign. At one point the city paid the users as much as $237 per acre foot, which cost the city hundreds of thousand of dollars each year and came out of the ratepayer-funded wastewater fund. In fact, the city still pays six agricultural users $185 per acre foot to take its recycled wastewater, spending approximately $160,000 per year on the outdated practice.

But all that is about to change. The city recently accepted proposals from all six agricultural users it currently pays — and two additional users it does not pay — on how much recycled wastewater they would like to purchase from the city. St. John said city staff is in the process of evaluating these proposals.

"We don't know what kind of revenue it will generate yet," he said. "But if we could save on the cost to dispose of the waste water,that would be a great first step."

St. John explained that the city is looking to make the transition as seamless as possible for the six agricultural users who have relied on this water as a necessity and as a source of revenue for more than 30 years. "We've made a commitment to work very deliberately with these users," said St. John. "These (agricultural) users have relied on this water for more than three decades so we want to be careful before we make radical changes to their livelihoods."

Earlier this year, the City Council agreed to begin selling its recycled wastewater to four other land owners. Jackson Family Investments, which is developing a vineyard in town, began purchasing the city's recycled wastewater at $820 per acre foot and agreed to purchase a minimum of 36 million gallons per year.

At the same time, the city also began selling its wastewater to three other users in town: Rooster Run Golf Course at a minimum of 102 million gallons annually, Adobe Creek Golf Course at 60 million gallons annually and the Karren Vineyard at 2 million annually, all at different rates.

The city currently charges different rates to users based on what the water will be used for. Golf courses are considered recreational usage and have been charged a lower rate since the city views the recreational services they provide as an asset to the community, whereas businesses like vineyards have been given a higher rate.

St. John said that the city could have contracts with the six agricultural users it's currently paying to take its recycled wastewater as early as this summer.

(Contact Janelle Wetzstein at janelle.wetzstein@arguscourier.com)