City of Orange City, IA

Orange City, IA

Key Features:

  • New flow-through sequencing batch reactor (SBR) wastewater treatment facility
  • Preliminary treatment includes spiral screening and grit removal
  • UV disinfection

Key Experience:

Wastewater Treatment Facility (SBR)

DGR Engineering (DGR) worked with the City to evaluate alternatives, which included constructing a sequencing batch reactor (SBR), mixed bed biofilm reactor (MBBR), retention and land application, activated sludge, or submerged attached growth reactor (SAGR). The evaluation considered capital costs, long-term operation and maintenance costs, operational flexibility and expandability. After consideration and numerous site visits, the City ultimately determined a flow-through style SBR system to be the preferred choice based on the selection criteria and the ability to meet anticipated permit limits.

Preliminary treatment includes a spiral screen and vortex grit removal system. The three-unit SBR follows the pre-treatment equipment. The combination of aeration on/off as well as mixing allows the facility to reach very low levels of ammonia, total nitrogen and phosphorous. An ultraviolet (UV) disinfection system follows the SBR units and was included to meet effluent disinfection requirements. A full-plant supervisory control and data acquisition (SCADA) system was incorporated in the project for remote monitoring.

The new system will utilize two existing lagoon cells for flow equalization and sludge storage prior to land application. During peak flow events, the facility can split flow to utilize the dedicated lagoon for equalization and then route influent wastewater back through the plant when flows subside. The facility was designed to treat a total flow of 2.45 million gallons per day (MGD) to accommodate projected 20-year domestic and industrial growth. The improvements made the facility easily expandable for future needs and was designed with impending nutrient limits in mind.

Total project cost was $9.9 Million. The City used local bonds for the project costs.

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Site Development

DGR Engineering (DGR) worked with the City and the project architect for all aspects of the project including topographic survey, site design, construction survey, construction observation and administration.

Site Development
Sioux City, Iowa

Sanitary Sewer Rehabilitation

The project was bid and came in under budget. Manhole lids were raised to provide better access in some areas, and rehabilitation of the sewer system was completed to give another 50 years of life to the City’s much-needed infrastructure.

Sanitary Sewer Rehabilitation
Rembrandt, IA

Wastewater Treatment Facility

MBBR technology was chosen based on cost, operational flexibility and most importantly, limited land availability.

Wastewater Treatment Facility
Sanborn, IA

Floodplain Analysis

DGR employed a Geographic Information System (GIS) in conjunction with the U.S. Army Corps of Engineers to first determine the 100-year flood elevations and delineate the floodway boundaries.

Floodplain Analysis
Sutherland, IA

Distribution Conversion

Due to concerns with the age and condition of the structures, along with safety clearances to energized equipment and conductors, a project was undertaken to replace the old infrastructure with new underground lines and associated padmount equipment.

Distribution Conversion
Redwood Falls, MN

Street & Utility Improvements

Morningside Avenue was reconstructed totaling approximately 1,300 linear feet. The project included new sanitary sewer, water main, storm sewer, fiber conduits, decorative street lighting, and 9-inch concrete paving with colored concrete sidewalks.

Street & Utility Improvements
Sioux City, IA