Wastewater Treatment
Wastewater Treatment Facility
Utility Solutions owns and operates a wastewater treatment facility located at Elk Grove Subdivision in Gallatin Valley, Montana. The facility was originally designed and constructed to serve the needs of the Elk Grove Subdivision with the ability to provide wastewater treatment and disposal to neighboring properties. The wastewater facility was purchased by Utility Solutions with plans to handle the regional wastewater treatment needs for the Four Corners County Water and Sewer District and the Utility Solutions service area.
The Elk Grove wastewater treatment facility is an Oxidation Ditch activated sludge treatment system with associated components originally designed by Fluidyne, Inc of Bozeman, Montana and Lakeside Equipment of Bartlett, Illinois. The facility consists of an extended aeration process with aerobic sludge digesters and secondary clarification. The existing treatment plant operates under Montana Ground Water Pollution Control System Permit (MGWPCS) permit number MTX000110. The wastewater treatment plant is capable of receiving flows from the greater Four Corners area by using existing capacity capabilities and by adding new modular components as required by the approved 2006 Wastewater Facility Plan Update.
Wastewater treatment effluent design parameters are based on groundwater quality considerations associated with a mixing zone and non-degradation analysis for groundwater discharges. In addition, subsurface discharge of effluent requires a lowered concentration of solids remaining in the water to minimize plugging in the infiltration areas. Effluent characteristics for the spray irrigation site are based on crop uses of water including transpiration and nitrogen uptake along with access to the site and/or harvested crop product. In either case, the effluent produced must have a reduced BOD5 (Biochemical Oxygen Demand), TSS (Total Suspended Solids), Total Nitrogen, Total Phosphorus, and Fecal Coliform as shown in Table 1. The Utility Solutions, LLC wastewater facility treats residential type wastewater and individual service connections are monitored to ensure reasonable wastewater constituents are discharged.
Table 1: Effluent Criteria
Effluent Parameter |
Treatment |
Treatment Basis |
BOD5 |
10 mg/L |
Prevent infiltration clogging |
TSS |
10-15 mg/L |
Prevent infiltration clogging |
Total Nitrogen |
10 mg/L |
Non-degradable & MTX000110 |
Total Phosphorus |
3 mg/L |
Non-degradable & MTX000110 |
E. coli Bacteria |
128 cfu/100ml |
MTX000110 |
The activated sludge plant process utilizes aerobic and anaerobic cycles to reduce BOD5 and Total Nitrogen contained in the wastewater. There are aeration rotors oriented perpendicular to the Oxidation Ditch channels that produce a higher concentration of oxygen in the water during the aerobic cycle of the process. During the anaerobic portion of the cycle, the rotors are placed on standby and the respiration of the organisms in the process use up the available oxygen. Proper alternation of aerobic and anaerobic processes will reduce the Total Nitrogen in the water. A secondary clarifier receives water overtopping a weir from the mixed liquor area of the Oxidation Ditch. The clarifier settles out suspended particles in the water to reduce the BOD5, TSS and Total Phosphorus that has been chemically treated with a flocculant. Following clarification, the effluent flows to a dose tank for storage prior to disposal. Utility Solutions, LLC has expanded the wastewater facility to include ultra-violet (UV) disinfection between the dose pumps and the discharge. UV disinfection of the effluent reduces the Fecal Coliform concentration to levels in compliance with the discharge permit. Waste sludge is treated by aerobic digestion and disposed by land application as soil enhancement or fertilizer. The combined treatment process is controlled by operators licensed with the State of Montana and test results are required by the discharge permit to ensure compliance.
