What will you do when your lagoon receives lower ammonia discharge limits? Are you looking for an ammonia removal solution for your lagoon, especially during wintertime?
Kremmling, Colorado is a small community in Grand County with 1,500 connections in the northwestern part of the state. Their wastewater is treated by an aerated lagoon system operated by Kremmling Sanitation District (KSD).
KSD’s Lagoon: The treatment plant consists of primary treatment (automatically raked bar screen), a covered complete mix pond (Pond A), and uncovered partial mix pond (Pond B), another uncovered partial mix pond (Pond C) and a covered settling pond (Pond D).
The facility discharges to Muddy Creek after a tertiary filtration and disinfection.
The Colorado Department of Public Health and Environment (CDPHE) issued the KSD effluent ammonia limits in 2011 as a part of the District’s wastewater treatment plant discharge permit renewal.
Frustrated by the new discharge permit, KSD turned to RG and Associates for a solution. Nick Marcotte, P.E. of RG and Associates who oversees this project, helped the District explore three possible operations:
Alternatives for Compliance
- Scrap the existing lagoon facility and construct a mechanical plant at an estimated cost of approximately $6,000,000;
- Construct a large lift station to relocate the lagoon discharge point from the existing receiving stream of Muddy Creek to the Colorado River where additional flows will dilute effluent ammonia at an estimated cost of $2,500,000;
- Pilot test the Bio-Dome® system, developed to nitrify ammonia in lagoon systems to determine the technology’s capacity and full scale cost.
Upgrading to Bio-Domes
Following years of tests and data collection from the pilot test in KSD’s lagoon, it was proved that the Bio-Dome® system removes ammonia in wastewater under near-freezing temperature.
It is estimated that an additional 480 Bio-Dome® units will be needed to allow KSD to have a maximum discharge of 5 mg/L ammonia with a flowrate of 0.30 MGD at a total Bio-Dome® system cost around $1,300,000. This cost is significantly less than the other two alternatives.
The Bio-Dome® technology obtained approval from CDPHE last year. All of these allow KSD to include Bio-Dome in their system to continue to operate for the foreseeable future.
By October of 2016, WCS installed 261 Bio-Dome® units in pond B. An additional 219 units will be installed around March 2017 in Pond C.
Key Benefits of the Bio-Dome®:
- A Bio-Dome® system represents the least expensive treatment upgrade available in terms of both capital expense as well as O&M expense.
- An upgrade utilizing Bio-Domes will not require operators with additional training, certification, and/or a higher pay grade.
- The Bio-Dome® system is intended to be a modular, expandable, system that is capable of growing with the facility over the next 20+ years.
- The Bio-Dome® system can be coupled with other, more conventional, technologies to address future Phosphorous or Total Nitrogen limits.
- Because of energy efficiency, the Bio-Dome® system can be considered “green” and will aid in qualifying the facility for Energy Efficiency grants if any are available through utility providers.
Bio-Dome® is featured in “Principles of Design and Operations of Wastewater Treatment Pond Systems for Plant Operators, Engineers, and Managers” (EPA/600/R-11/088).
For more on how a Bio-Dome® solution can keep your lagoons compliant at a cost you can afford,