City of Dell Rapids
Dell Rapids, SD
- 750,000 gpd capacity
- Pre-treatment includes spiral screen and grit removal
- UV disinfection prior to discharge
Wastewater Treatment Facility (SBR)
The City of Dell Rapids, SD, with a of population 3,705, was placed under a construction order as part of their new Surface Water Discharge Permit. Effluent ammonia levels over their permit limits had caused several violations and the South Dakota Department of Environment and Natural Resources (DENR) required upgrades to their system to address these issues.
The previous treatment process utilized an aeration lagoon, followed by a series of facultative lagoons. With a total project cost of $4.7 million, the new SBR system utilizes the existing aeration lagoon for equalization and another lagoon cell for sludge storage, which reduced the cost of the project for the City and provided more operational flexibility. The equalization basin reduced the peak flow design requirements of the new treatment equipment because the high flows can be diverted during a large rain event until the flows subside to or below the design capacity of the SBR system and then rerouted back through the new treatment system.
The SBR treatment process provided a cost-effective solution to meet ammonia limits as well as being set up for anticipated total phosphorus and total nitrogen limits. The DENR was consulted during the design process to help establish effluent limits. Once these limits are implemented, the treatment cycles can be modified to meet total nitrogen limits, while a chemical feed system may be needed to meet future phosphorus limits.
- Electrical Power
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.
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.
Wastewater Treatment Facility
MBBR technology was chosen based on cost, operational flexibility and most importantly, limited land availability.
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.
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.
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.
Sioux City, IA