Finding a good use for wastewater
Published: Friday, May 11, 2012 at 9:25 a.m.
Last Modified: Friday, May 11, 2012 at 9:25 a.m.
Wastewater is something that most people don't often ponder, preferring to forget about it as soon as it swirls away down the toilet — but it is becoming increasingly valuable for the city, and may eventually bring some relief to the ratepayers.
On Monday, the City Council approved an agreement with a vineyard company, Jackson Family Investments, that the city hopes will start a new trend of charging agricultural users for the treated effluent, assuming that other vineyards and ranches will be willing to pay for the water.
Jackson Family Investments will buy 50 acre feet, or 16 million gallons, of recycled water treated to the secondary level for a five-year term.
“It's a great opportunity, a win-win,” said Dan St. John, Petaluma's new public works director. “What we pass tonight will be a model for future agreements with other users.”
Until 1976, the idea of making money off treated wastewater would have been laughable — it was something to be gotten rid of, and the city did so mainly by releasing it into the Petaluma River.
But that year, a study found that treated wastewater could be used to irrigate a range of crops, and the city began to look at recycled water as a resource. Petaluma undertook a partnership with several ranches and vineyards to use the water to irrigate crops. At that time, with the idea of reusing wastewater still a foreign and slightly unsettling concept, the city paid the farms to put the water to good use.
It also helped the city get rid of the water in the summer months, when it is not allowed to release it into the Petaluma River.
At one point, the city paid the farmers as much as $237 per acre foot, costing the city hundreds of thousands annually, which came out of the ratepayer-funded wastewater fund.
But over time, as the supply of available fresh water grew scarcer and more expensive, and the public more comfortable with the concept of using recycled water, the cost the city pays the farmers to take the water has dwindled. Currently, the city pays six agricultural businesses $185 an acre foot.
Rooster Run Golf Course, Adobe Creek Golf Course and a small vineyard, meanwhile, have already started paying a small fee to use recycled water — Adobe back in 1990 and the other two in 2005, according to city staff.
And under Monday's agreement, the city will start selling its recycled water at $820 per acre foot — first to Jackson Family Investments, then to the other agricultural users as their contracts expire in 2013. St. John estimated that the revenue from wastewater sales will grow to about $220,000 each year or higher.
The annual budget to cover operating costs for the recycled water program is $315,000 — so while the program still won't pay for itself by selling recycled water, it will cost the ratepayers less.
Ratepayers probably won't see an actual reduction in their rates, but the rates may go up slower because of the savings.
Some local residents have raised concerns about how clean recycled water really is, and if trace contaminants could have a negative impact on crops or the ecosystem. Others have objected to the cost of the city's water recycling program and its new, expensive wastewater treatment facility.
Currently, the city is selling mostly secondary treated water. The new Ellis Creek Water Recycling Facility also has the ability to recycle water at the tertiary level, which results in a cleaner product. But this is much more costly, and the city must still develop infrastructure needed to deliver the water.
But the trend of using wastewater as a resource isn't specific to Petaluma. As water becomes a scarcer and more precious commodity, recycled water is increasing in value, and cities like Redwood City and San Francisco are finding creative ways to use — and sell — it.
“Wastewater is becoming a commodity,” St. John said.
(Contact Jamie Hansen at jamie.hansen@argus courier.com)
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