Diesel prices reached $8.33.9 a gallon at the Flying J travel centers in Ripon and Lathrop on Tuesday.

The prices aren’t spooking Manteca’s solid waste division that operates 40 plus large trucks collecting the city’s garbage, recyclables, and organic/green waste.

In fact, Manteca is saving a bundle when it comes to diesel costs.

It’s because Manteca has its own refinery.

And they don’t have to worry about raw fuel supplies from the Middle East where the lion’s share of crude comes from to power vehicles, trucks, heavy equipment, jets and more in California.

The “crude” supply to Manteca’s refinery won’t be interrupted as long as the city’s 98,000 residents keep flushing.

The refinery is the city’s wastewater treatment plant.

And the crude is the No. 2 we flush down the toilet.

Manteca was among the first — if not the first — pioneer city in California to convert methane that is a byproduct in treating wastewater into biogas or compressed natural gas.

That gas is currently used at a fueling station not included in the count of existing locations or those already in the approval project when it comes to the city’s temporary moratorium on new gas station applications.

It’s at the wastewater treatment plant.

Currently, it is powering 35 city solid waste collection trucks, five Manteca Transit buses, two pieces of water division equipment and one piece of wastewater division equipment. All of those vehicles would be going through $8.33.9 per gallon diesel right now if it wasn’t for the city’s sewer to fuel program.

But that is just the tip of the green benefits.

Methane gas — whether it is from cows passing gas, fossil fuels, landfills, or wastewater treatment plants — are the No. 1 public enemy when it comes to greenhouse gas emissions.

Almost all wastewater treatment plants simply burn the methane gas off into the air hence the “eternal flames” most sewer treatment facilities have.

The only exceptions in California are Manteca, several cities in the Los Angeles Basin and now Fresno.

Manteca has eliminated a major local source of greenhouse gas emissions with its sewer to fuel program.

It also has reduced air pollution in city neighborhoods where three separate solid waste trucks roll through each week to collect garbage, recyclables, and organic/green waste given CNG burns significantly cleaner than diesel.

As an added bonus the CNG powered solid waste trucks run much quieter than diesel.

The city has placed a food waste separator at the Lovelace Transfer station to separate organic waste from the trash stream.

The city eventually plans to use food waste to expand the production of biogas at the wastewater treatment plant.

For now, while the city works toward taking that step, the separated food waste is diverted to a composting facility.

The ability for Manteca to generate its own fuel was part of a 2016 project.

It was a $20.1 million undertaking to rehabilitate and prevent structural failings at Manteca’s municipal wastewater treatment plant.

Staff — after researching the technology — made a case for adding the biogas production component given work was already being done.

The work involved installing two new 65-foot diameter anaerobic digesters, construction of a new digester control building, repair of two existing 60-foot diameter anaerobic digesters, installation of a new compliant flare system, installation of new compliant boilers, installation of new gas handling and treatment equipment plus other associated improvements.

If that sounds like a mouthful, then frame the expenditure this way: It made it possible for Manteca to continue processing wastewater generated by its 98,000 residents and a large chunk of Lathrop’s 40,942 citizens to a high environmental standard while at the same time putting apparatus in place to produce biogas.

Due to that project, wastewater is cleaned to the point it is one process short of being drinkable as it has been for more than 25 years.

It assures the treated wastewater that Manteca in the coming years will recycle to irrigate municipal parks continues to be significantly cleaner that the water in the San Joaquin River where it is released.

The $6 million project to build the compressed biogas fueling facilities was paid in part with a $1.8 million grant from the San Joaquin Valley Air Pollution Control District.

The city also secured a $3 million grant from the California Energy Commission leaving less than $1.2 .million for a subsequent bond issue to help cover plant upgrades.

And as a nod to the city’s financial acumen, sewer bonds the city issued for the overall work came in at a lower interest rate to reduce overall costs to municipal ratepayers.

The pending addition of floating solar panels at the treatment plant will stabilize $2.5 million in annual electricity costs and generate future savings.

In doing so, not only does Manteca arguably have the greenest waste water treatment plant in California north of Fresno, but it will also help save ratepayers even more green.