Construction Update 07: Major Headworks, Clarifier, and Oxidation Ditch Progress

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An aerial view of a large, circular oxidation ditch under construction. The ditch has multiple concrete walls and a central section with a water channel. There is also a smaller, circular tank filled with blue water nearby.

This week's update includes significant construction progress on various components of the Niwot Sanitation District's wastewater treatment facility. The headworks structure is fully prepared for the next concrete pour, with rebar and wall forms in place. The clarifier has passed its water test, and scum pit construction is set to begin shortly. Rice Lake West achieved a major milestone by reinforcing and pouring the oxidation ditch's main walls ahead of the first frost. Additionally, the first concrete walls for the dewatering building have been poured. Lastly, the gravity main and non-potable lines are nearing completion, with installation of manhole inverts currently underway.

Our office remains open during regular hours — Monday through Friday from 9:00 AM to 3:00 PM.

Headworks Structure Prepped for Next Phase

An aerial view of a construction site showing the foundation of a building. The foundation includes rebar and wooden wall forms.

The photos above show the rebar and wall forms installed around the headworks structure, fully prepared for the next pour day.

Clarifier Passes Water Test, Scum Pit Construction Set to Begin

An aerial view of a large, circular clarifier tank under construction. The tank is filled with blue water and surrounded by a concrete wall. Construction equipment and materials are visible nearby.

The clarifier has successfully passed its water test and is now ready for the installation of scum pit forms and rebar. Weather permitting, we aim to complete the scum pit by the end of the week.

Rice Lake West Completes Major Milestone Before First Frost

An aerial view of a large, circular oxidation ditch under construction. The ditch has multiple concrete walls and a central section with a water channel. There is also a smaller, circular tank filled with blue water nearby.

The oxidation ditch’s main walls have been poured — marking a major accomplishment for Rice Lake West in completing these large concrete sections ahead of the first frost.

First Walls Poured for Dewatering Building

An aerial view of a construction site showing the initial concrete walls poured for the foundation of a dewatering building.

Shown above is the first set of walls poured for the dewatering building, with forms and rebar being installed for additional pours over the coming days.

Gravity Main and Non-Potable Lines Near Completion

An aerial view of a construction site showing a long, deep trench with a blue pipe running through it. The trench is surrounded by piles of dirt and other construction materials. In the background, there are several large tanks and a building.

The gravity main and non-potable lines are nearly complete, with backfilling and manhole invert installation now underway. This will raise the new manholes above ground level to prevent infiltration from ground and surface water.

What's next?

Next week, we will be pouring the wall forms for the Headworks. The Oxidation Ditch requires two small pours to complete the interior ring. In the Clarifier, we will set the rebar and forms for the scum pit and proceed with backfilling. More walls for the Dewatering building will also be formed and poured. Additionally, installation and backfilling of gravity lines and non-potable lines will continue. Please note that all activities are contingent on weather conditions and temperatures during next week's construction.