Wonders and Woes of Fairfield’s sewer system: Part 3 of 3

Now that Fairfield has nearly completed a multi-million-dollar upgrade to its sanitary sewer system, you might want to understand what all that effort has produced. Here’s how it works today.

Gravity transports sewage via a network of pipes and trunk lines from all parts of Fairfield to more than sixteen “lift stations.” These are located at low points throughout the town and take over from gravity to push the sewage the rest of the way to the Wastewater Treatment Plant (WWTP) south of Highway 34.

Sewer pipes generally run underground. Since the WWTP is raised, there is a need to elevate the flow of sewage as it arrives onsite. This is accomplished at the Pump Building by giant augurs (like big screws) which bring the flow up into the facility and provide initial aeration for the influent.

Next, sewage goes to the Head Works Building for filtering and removal of inorganic materials. This is mostly automated, but too often, the Works must be halted to manually remove (not a fun job!) clogs of inappropriate contaminants, such as “flushable” wipes, the bane of the WWTP crew’s existence. Wipes may be “flushable,” but they don’t degrade and should not be put down the plumbing. Instead, they should be placed in the trash to go to the landfill. Other problematic items include fats, oils, and grease; these can be disposed of at Connelly’s or Waste Management.

The filtered sewage water is sent to large outdoor aeration tanks, where cultivated anaerobic and aerobic bacteria are alternately activated in different parts of the tanks. The bacteria do the bulk of removing toxins; no chemicals are used. The sediments and bacteria that settle to the bottom of the tanks - the “sludge”- are collected and stored in another large tank where they compost until they are eventually ready to be used as fertilizer. This is an important circular aspect of the facility: repurposing waste for another use by reapplying it to enrich soil.

As a final step, after the bacteria have metabolized the sewage and the sludge has been removed, the remaining liquid undergoes Ultra-Violet (UV) light treatment to destroy any remaining harmful bacteria. The resulting water is discharged into Crow Creek or provided to a golf course for watering, with some additional treatment. This is another application of a circular model: repurposing grey water to meet irrigation needs and keep streams flowing with clean water.

There have been positive results from this massive upgrade. First, we now have a state-of-the-art WWTP. Second, we have nearly eliminated Sanitary Sewer Overflows, welcome news for homeowners and neighborhoods. Third, we’ve improved our watershed by sequestering sewage from stormwater and groundwater.

In fact, a landowner along Crow Creek downstream of the WWTP says, “On our land, we’ve seen a dramatic increase in aquatic and land-based animal life and a healthier diversity of birds and plants since the system was overhauled. We’re delighted!”

Aren’t we all!

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