Microbrewery receives enhanced secondary treatment for substantially greater capacity
Founded in 1989, the Long Trail Brewing Co., one of the top 25 craft breweries in the nation and a local attraction, quickly outgrew the capacity of its basement location at a woolen mill in the town of Bridgewater, situated in Vermont’s Green Mountains. In 1995, the brewery relocated to a larger facility nearby with a wastewater treatment plant designed to treat high-strength wastewater with a BOD5 concentration of approximately 10,000 mg/L.
Continued success resulted in increased production volume and the need for a solution that could handle a significant spike in high-strength brewery waste. It also had to be cost-effective and meet the confines of the brewery’s limited footprint. In addition, the Long Trail Brewing Co. wanted to find a way to enhance nitrification and denitrification to protect the environment by providing a higher level of nitrogen removal and overall treatment plant stability.
A Cost-Effective & Sustainable Process
An upgrade to the existing activated sludge system using membrane bioreactors or high-rate anaerobic treatment technology initially was considered. Ultimately, the BioMag system from Siemens was chosen.
The brewery selected the system because it would be able to cost-effectively increase the wastewater treatment facility’s capacity, without the need to increase tankage or physical footprint.
Simple to integrate, operate and maintain, the BioMag system uses magnetite to ballast biological floc, enhance treatment capacity and improve performance without adding capital-intensive new tankage or energy-intensive operating costs. With a specific gravity of 5.2 and a strong affinity for biological solids, magnetite substantially increases the settling rate of biological floc, providing reliable control over the depth of secondary sludge blankets, as well as increases in mixed-liquor suspended solids (MLSS) concentration. Higher MLSS concentration enables the treatment of increased hydraulic flows or surges and loadings, all within existing tankage.
The system uses the following process:
Advantages of the system include:
One Compact System
With the new system, the Long Trail Brewing Co. generated additional savings by enabling the company to process heavy yeast concentrations produced by brewing on site instead of transporting them off site for disposal.
Although the average daily effluent discharge has increased steadily since 2006, the monthly average BOD5 and total suspended solids in the effluent have decreased.
The installation team also helped facilitate full nitrification/denitrification, including upgrading their existing anoxic zones, adding a post-anoxic zone and adding more aeration capacity.
“The BioMag system produced results that enabled the brewery to produce a higher volume of product with an increased treatment capacity, while not increasing its physical or ecological footprint,” said Brandon Mayes, assistant quality assurance manager for Long Trail Brewing Co.
The brewery experienced the following results with the new treatment system:
As a winner of the Vermont Governor’s Award for Environmental Excellence, the Long Trail Brewing Co. ranks eco-friendly and sustainable practices as a high priority. The BioMag system exceeded the company’s expectations as an efficient solution for enhanced capacity and superior nutrient removal, as well as a sustainable process for lower operational expenses.