By allowing ads to appear on this site, you support the local businesses who, in turn, support great journalism.
Rumplestiltskin, Manteca-style, turns sewage (& the attached land) into gold
sewer gold
A City of Manteca solid waste truck used to pick up and deliver large collection boxes is being fueled with compressed liquefied gas.

Manteca’s version of the Brothers Grimm fairy tale Rumplestiltskin is far from complete.

But instead of spinning straw into gold Manteca is converting methane gas produced from treating sewage into the gold standard for being green.

For more than a year, methane gas has been combined with food waste at the municipal wastewater treatment plant to produce compressed liquefied gas. That gas fuels a portion of the city’s solid waste collection fleet that picks up garbage including the very food waste that helps power the trucks.

Eventually the city’s fleet of nearly two dozen solid waste trucks will be converted with fuel from Manteca’s own “refinery.”

Not only is the food waste not buried but methane gas is now rarely burned off into the air during the wastewater treatment process. The trucks that run on the “food waste gas” do not generate air pollution and run much quieter.

It also will ultimately reduce costs running the gamut from not having to purchase fuel to engines with a longer lifespan. The process will also avoid the high cost of landfilling food waste.

You can count on one hand the number of cities in the West that have turned their municipal wastewater treatment plant into biogas refineries. There are those that send them to private concerns that do the same without the benefit of using methane gas people created that — when it is burned off at treatment plants — becomes a part of the vexing methane problem.

Scientists indicated methane contributes to nearly half the global warming impacts in the short term.

If that food is buried, it will also create methane gas.

Based on 2018 numbers, the United States throws out 80 billion pounds of food waste a year. More than three quarters of it is landfilled. It also constitutes the largest volume of what gets buried in diminishing landfill space. As that food waste breaks down, it creates the equivalent greenhouse gas emissions of 3.4 million cars annually.

That means the simple act of school children, grocery store stocking clerks, and restaurant staff dumping food waste into the orange carts provided by the City of Manteca is reducing global warming. It might be on a minuscule scale compared to the overall problem but just like pennies add up so does efforts to reduce greenhouse emissions.

How Manteca became a leader has everything to do with how it approached the problem of wastewater treatment and solid waste as well as the fact as a full-service city it is a growing rarity in California. That means Manteca has control of its own water and wastewater systems, handles its own garbage collection as well as operates its own fire and police departments instead of relying on a fire district or contracting out law enforcement services to another agency.

The driving force behind Manteca’s progressive green decisions over the years has been saving green.

Being in control of all facets of public works has allowed a holistic approach. When Manteca needed a new aerobic digester to replace aging equipment at the treatment plant, they looked at ways they could reduce long-term costs as well as meet tough state mandates.

They were able to implement the food waste to gas solution because they controlled all aspects of the infrastructure. They were also looking beyond the short-term horizon as well as for inter-department efficiencies.

One hopes they can pick up their game as well with the rest of the solid waste they handle. One of the possible solutions is establishing the city’s own sorting and composing facility at the wastewater treatment plant where fiber-based materials such as paper and non-corrugated boxes and such are combined with green waste from yards.

How Manteca has viewed — and constantly re-examined — its wastewater treatment plant has been paying off in ways only other cities can dream about.

Back in 1966 Manteca spent $39,000 to purchase 56 acres for future expansion of land disposal of treated wastewater. The land was held in reserve for dispersing treated wastewater in the same manner nearby city land leased to farmers was irrigated to raise corn for use as dairy cattle silage.

The 1966 purchase was done to get ahead of the state that at the time was threatening to eventually ban the return of treated wastewater to rivers. Technology, of course, has changed. It is to the point the current Manteca treatment process turns out water that is not only significantly cleaner than the river but is one process shy of being drinkable. As such treated water is still allowed to be returned to the river.

That is when the city started looking at 56 acres they had bought for future land disposal in a different manner.

About the time the first tract home was built south of the 120 Bypass city leaders had the foresight to see the acreage that was part of the wastewater treatment plant for land disposal was growing in value due to its location. This was 20 years ago when traffic was far from an issue on Airport Way, Costco wasn’t on the radar, and not a single commercial venture — retail or dining spot — existed along Airport Way from Finley’s Bar & Grill a half mile south of French Camp Road to Jimmy’s One Stop on the west side of the San Joaquin River.

First, to make sure all bases were covered they bought 200 plus acres on Hays Road south of Manteca for possible use as “spray fields” to dispose of treated wastewater if they were forced into such a scenario. All that would be needed to make it work if that were to become a necessity is to install purple pipeline to the site.

The first use of land bought in 1966 after it was determined not to be critical to the treatment process was to create the 30-acre Big League Dreams sports complex. The second was the 500-room Great Wolf indoor water park resort deal.

Not only is the largest hotel ever built in the Central Valley between Redding and Bakersfield expected to lure 500,000 people a year to Manteca on what was once going to be wastewater spray fields but the hotel has a commanding view of the wastewater treatment plant.

The third use that the city is now pursuing is a 100-acre family entertainment zone with everything from restaurants to amusement venues bookended by Great Wolf and Big League Dreams. That also would go on land bought for spray fields but purchased separately.

If you’re not impressed by what Manteca has down with its wastewater treatment plant and adjoining land set aside for spray fields, perhaps money will turn your head.

The city essentially leveraged under $15,000 they spent for 30 acres for spray fields into a $180 million private sector investment by Great Wolf that will send $1.7 million annually to start with into city hall coffers, employ 500 people, and attract 500,000 people a year to partake in a mini-vacation in Manteca.

Not bad for a place that some contend is run by country bumpkins and is inferior to the Bay Area.


This column is the opinion of editor, Dennis Wyatt, and does not necessarily represent the opinions of The Bulletin or 209 Multimedia. He can be reached at