Our Projects
Submerged Attached Growth Reactor (SAGR) Systems
Innovative SAGR systems are the perfect solution for smaller communities—with smaller budgets—needing to upgrade their lagoon-style wastewater treatment facilities to meet stringent EPA quality standards for ammonia removal, even in cold weather.
The biggest problem with lagoon-cell wastewater-treatment facilities is that they weren’t designed to meet the Environmental Protection Agency’s increasingly stringent standards for ammonia removal, especially when the temperature drops during Midwestern winters. Unfortunately, the cost to build a new mechanical wastewater-treatment plant is beyond the reach of many smaller communities.
That’s why Nelson Environmental of Winnipeg, Canada, developed the Submerged Attached Growth Reactor (SAGR) wastewater-treatment system. SAGR is the efficient, cost-effective solution that enables smaller communities to retain their lagoon-cell facilities
and meet EPA standards year-round.
Crosby Construction is the first and only company to install SAGR systems in Indiana. The cost to create a SAGR-based
wastewater-treatment facility is much less than the cost to build a new mechanical plant and each system depends
on the size and number of lagoon cells a community operates.
SAGR: a simple innovation
- Modifications to existing lagoons often not required.
- Aerated gravel beds with horizontal flow-distribution chambers that distribute influent wastewater across the width of each cell.
- On-site blowers feed the submerged aeration systems.
- Blowers are the only mechanical components.
- An effluent collection chamber at the back end of the lagoon collects all the treated effluent and channels it to the
discharge structure. - Can be combined with aerated or facultative lagoons to meet effluent ammonia requirements in systems that operate
as continuous discharge or controlled discharge. - No aeration is required in the lagoons to meet the recommended lagoon effluent BODS feeding the SAGR process.
Performs in cold climates
SAGR is perfect for post-lagoon nitrification in severe cold to moderate climates where water temperatures can be below
0.5°C for extended periods of time. Municipal effluent quality at <0.5°C water temperature:
- CBOD <5.0 mg/L
- TSS <10.0 mg/L
- Total ammonia <1.0 mg/L
- E.coli <200 FCU/100 ml
- Total coliform <1000 FCU/100 ml
Easy to operate and maintain
- A simplified control scheme manages the day-to-day operation of the blowers.
- An operator will typically perform a systems inspection using a simplified systems check list, and on occasion,
change lubricating oil. - Approximately every six months, the filters in the blower units should be changed. It takes just a few minutes.
- Twice a year the operator should initiate the step feed system by fully opening and fully closing two separate valves.
Efficient and cost-effective
An estimated energy savings of 50 percent compared with the cost to run blowers for a conventional aerated lagoon system.
Call us today
For more information about SAGR systems, speak to one of our wastewater-treatment professionals at (260) 432-5114.