The City's sewer plant expansion has been making good progress according to the project's design and construction managers, TEC of Fort Collins, Colorado.  This important new facility will take eighteen months to build and cost some  12.5 million dollars. Updating and modernizing  the plant will allow it  to treat 4.2 million gallons of wastewater a day and meet the State's clean water requirements.

Population growth and stricter regulations are affecting many communities in Wyoming and the wastewater plant in Rock Springs has been feeling these pressures for some time. Flows have increased close to the old plant's  maximum capacity and the anticipated growth in housing and new business brought on by the energy boom are predicted to boost the flow substantially over the next few years. City leaders are anxious to avoid any problem which could affect the town's booming economy, and the  Wyoming Department of Environmental Quality wants the city to limit the ammonia and prevent  any free chlorine from leaving the plant. The DEQ's new  "National Pollutant Discharge Elimination System" permit leaves Rock Springs no choice but to change the treatment process used to clean the city's wastewater.

The Engineering Company (TEC) was selected to design and manage construction on the project in mid-summer of 2004, and has a long track record with the City.  TEC successfully designed three of the plant's previous major projects beginning in 1997.  Alder Construction of Salt Lake City, Utah is the general contractor for the current expansion project and has been on the job since August 15th.

The project includes construction of two final stage clarifiers, an oxidation ditch, a grease trap, a drain pump station, an effluent pump station, an influent pump station and a Classifier Suspended Solids Screening and Dewatering (CSSD) building that will house equipment and controls for operating the process. Modifications will also be made to the existing digesters, main pump house, primary effluent building and oxidation ditch. The new oxidation ditch, clarifiers, and CSSD building are under construction now with everything going well.
 

Building basin drain pump section- OxyDitch2 in background	Placement of building basin drain pump station bottom
Oxycation Ditch-2 Steel Work	Oxydation Ditch-2
Clarafiers 3 and 4 under construction	Interior walls start to take shape.
Another section of the wall being poured.	The 18" outer wall of the Oxydation Ditch is begun.
	Finished floor of the oxydation ditch.
The Clarifier floor rebar being laid. All the floors were covered and kept wet for 7 days to cure the concrete.	The oxydation ditch floor is 20" thick and took 1,250 cubic yards of concrete.
A pump truck was used to place concrete on the oxydiation ditch floor.	The gravel was compacted before pouring the floor of the oxydiation ditch.
7 thousand yards of 3/4" gravel were brought in for structural backfill.	69 piles were driven up to 65 feet deep.
Excavation of the three main basins. 45,000 cubic yards were removed during this stage of construction.