Sun Tan Valley, AZ: Copper Basin Water Reclamation Plant (WRP) and Lagoons

(Satellite, the triangle of dirt north of the UP tracks)

The Walsh Group posted four photos with the comment: "Placing the Miraculous Medal in our first concrete pour for the new Copper Basin Water Reclamation Facility in Sun Tan Valley, Arizona. Copper Basin will replace an existing and outdated lagoon-style plant that was constructed more than 20 years ago. The new plant will allow EPCOR to return more than one billion gallons of safe, clean water annually to the natural water cycle through aquifer recharge."

[It is interesting that they use both a crane with a bucket and a pump truck. ]

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There were a couple of phrases in that post's comment that caught my eye and motivated me to dig deeper:

• "lagoon-style plant," sounds like an open cesspool
• "aquifer recharge," do they pump the water into the ground?

I'm used to Waste Reclamation Plants (WRPs) that use concrete rectangular and circular tanks for multiple stages of solid settlement and digestion. These are "activated sludge" designs. (The "activation" is a special bacteria that eats the organic waste material.) For example, the Stickney WRP uses this design. A quick check of a satellite image shows that my local town, Downers Grove, IL, also uses this technique. Note that these Midwest plants are located close to a stream or river into which they can dump the treated water. 

Satellite

After some research, I determined that lagoons are, in fact, open cesspools. But they can be effective in areas that are hot, land is cheap and the population is low. Depending on the design of the lagoons, water is retained for treatment for days to months. [deu]

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[Note that my concerns about algae control on the lagoons are well founded. I believe the green in the lower-right corners of some of those ponds is algae growth.]

A diagram of the new facility taught me about "aquifer recharge." I presume that all of those recharge basins get rid of the water by letting it soak into the ground. (Actually, I wonder how much of the water evaporates rather than soaks in.) Looking at a satellite map, there are some creeks in the area, but they are all dry. In fact the Salt River would be dry in Tempe, AZ, if it did not have a retention dam.

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(That diagram is also what allowed me to determine where the facility is being built. Although I was confused for a while because Sierra Vista Drive has yet to appear on the satellite map.)

I kept coming across the same press release that says: "The new state-of-the-art facility’s treatment process will be fully enclosed and designed to integrate seamlessly into the community. Equipped with industry-leading advanced treatment technologies that meet the Arizona Department of Environmental Quality’s Best Available Demonstrated Control Technology (BADCT) requirements, Copper Basin will ensure delivery of safe, clean, and reliable wastewater service." [e.g. GlobeNewsWire]

But the only information I found about the "state-of-the-art treatment process" is that it uses "biological processes." ("EPCOR has vast experience building and maintaining safe, enclosed water reclamation environments that integrate unobtrusively into their communities. In addition to being fully enclosed, our facilities use biological processes rather than rely on chemicals to treat wastewater. Our Verrado and Anthem (north Phoenix) facilities are examples of this approach" [epcor]) Because a building in the diagram is labeled "Bioreactor," I presume that treatment process is basically a big, above ground, septic tank. (I briefly looked on a satellite map around Verrado and Anthem to find what existing facilities look like, but I could not find anything.)

I finally found that the lagoon facility was "at Magic Ranch." [PinalCentral] That was the clue I needed to find it. One of the reasons to replace this facility is that people complain about the odors. I can easily believe that most of those lagoons stink.

Satellite

2 of 3 photos posted by The Walsh Group, Jan 2023.

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