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Myers and Sons Construction Building Wastewater Treatment Plant for Lytton Rancheria Tribe in Windsor

Myers and Sons Construction (Myers and Sons) began working on a water treatment plant for the Lytton Rancheria of California (Lytton Tribe) in August 2021. During construction, the Lytton Rancheria Tribe also decided to construct their own wastewater treatment plant, and once again hired Myers and Sons to get the job done. Barron Sweet has been working as a Superintendent for Myers and Sons for nearly eight years and has more than 35 years experience in the civil general engineering construction business. “We were around 50 percent complete with the Lytton Rancheria Tribe water treatment plant when they asked us to also build the wastewater treatment plant across the street,” says Sweet. “We broke ground in June 2022 after all of the design work was complete and should have the plant tested and commissioned by October 2023.”

Sweet explains that before his crews mobilized onsite, Ghilotti Construction had to do their job to complete the civil work necessary for Myers and Sons to begin. Ghilotti serves as a subcontractor to Midstate Construction Corporation who is a subcontractor to Myers and Sons who is the prime general contractor onsite. A big part of Ghilotti’s work was to excavate and construct an approximately 13.8 MG seasonal pond to handle the overflow from seasonal rains or storage overflow. They also excavated and constructed the levee around the pond. “Once the seasonal pond and levee were excavated and constructed, we came in with our subcontractor, Barber Webb Co., who then installed HDPE liner throughout the pond. After this, we were able to then tap into it with a 18-inch overflow pipe,” says Sweet. “The next job at hand was to excavate and construct a recycled pump station and UG emergency storage tank to help manage the wastewater and keep the plant running efficiently. According to Sweet, the construction of the 18-foot-tall by 24-footwide reclaimed water structure required his crews to dig into the side of the levee and excavate down around 30 feet.

Once the reclaimed water structure was complete, Myers and Sons crews moved on to the next step of constructing a 110,000-gallon emergency storage unit to a depth of around 25 feet. This 90 foot by 60-foot structure is designed for emergency use during a 100-year flood or in the event the storage pond is at full capacity and more space for water storage is needed. “The UG emergency storage structure was originally designed to be a precast structure, but due to the long lead time for the precast sections, Myers worked with the design team to change the design to cast-in-place. This was a wise decision as it saved us around four months’ time had we instead waited,” continues Sweet.

While one of Myers and Sons crews was constructing the emergency storage unit, another was busy digging, forming, and pouring the Operation’s Building foundation. “The 85-foot by 32-foot Operations Building pad is around two feet thick with cement building block on top,” continues Sweet. “Midstate Construction performed all of the block wall work along with the buildout of the restrooms, chemical storage rooms and other buildouts.”

Myers and Sons is currently at around the halfway point of construction on the Membrane BioReactor (MBR), a process that is now widely used in both municipal and industrial wastewater treatment plants. The MBR combines a microfiltration or ultrafiltration membrane unit with a suspended growth bioreactor to provide an advanced level of organic and suspended solids removal. “The MBR system for the Lytton Rancheria Tribe is designed and being constructed so that additional holding tanks can easily be added with basic connections. We are building seven 10-foot-high by 8-foot-wide by 40-foot-long rectangular tanks right now with the capacity to add three more in the future,” says Sweet. “These tanks will all sit upon a massive 115-foot by 72-foot pad that we poured in late February. Then, our subcontractor, Cloacina/FRM, will set the storage tanks on top for use in processing the treated wastewater.

Sweet says that his crews are now just getting into all of the underground pipe installation work. “The deepest sanitary sewer sections will be at around 31 feet deep and some of the other pipe will be as shallow as only three feet. We are using both slide rail shoring systems and quick shore units, along with conventional benching and sloping techniques to get the pipeline safely into the ground,” says Sweet. “One of our greatest challenges with the excavation of the pits and trenches has been the tremendous amount of rain we received this past December and January. The rains pushed things back a bit and filled up our emergency storage tank, but we got things back on track with constant dewatering with 4-inch pumps for around three weeks. Thank God we had our seasonal pond to dump into during this time because I think we moved more than 250,000 gallons of water and it had to go somewhere.” Sweet says that other challenges included supply chain issues with things like valves, piping and electrical panels. “We are just now receiving the valves and piping and some other materials are still two to three months out. The electrical panels may take as long as ten months to receive from the time we ordered. But everything has been manageable, and we are expediting these delivery dates whenever possible,” continues Sweet.