Paso Robles News|Tuesday, September 28, 2021
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City’s new wastewater plant begins operations 

Quality of water released into Salinas will be significantly improved

Paso Robles City Wastewater Manager Matt Thompson announced today that after two years of construction activity and preparation, yesterday the City’s new wastewater treatment process was fired up. Paso Robles muni bond rating

This includes new headworks for trash and grit removal, improved primary clarification, a new biological treatment process, new secondary clarifiers, and an improved disinfection process.

“Yesterday we kickstarted the new biological process with six truckloads of microbiology (“seed sludge”) from a neighboring city. The new process is now getting established and within a week or two the quality of water we put into the Salinas River will be much improved compared to the previous treatment process,” said Thompson.

Yesterday marked the beginning of 30 day period in which city operators will be, “working out bugs in the system,” refining the process, and getting coaching by experts on how to properly run the system.

“Startup of the new treatment process will allow us to demolish the rest of the old treatment process, build another secondary clarifier, and finish up the project this fall,” Thomson said.

Note regarding odors:
According to Thompson, the old treatment process occasionally smelled bad when passing the facility on the freeway due to the trickling filters that were used for biological treatment. Those trickling filters have now been shut down and replaced by a new biological nutrient removal (BNR) process. The BNR is less open to the atmosphere and will generally emit much less odor than the trickling filters.

“However, if you pass the facility on the freeway in the next couple of weeks, you may get a slight odor of wet grass. This is due to natural decomposition of the old biology on the trickling filters. This odor should diminish fairly quickly (within a couple of weeks) as the trickling filters dry up,” Thompson said.



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