In 2005, The Colony needed to expand capacity by 33% from 3.4 million gallons per day (MGD) to 4.5 MGD. Additionally, they needed to nitrify year round to below 3 mg/l. The Colony installed Webitat Modules in their two train, concentric ring plant, and converted from contact stabilization to the IFAS mode. The first train of 12 modules was installed and began service within 24 hours of initial draining. In 2006, additional modifications were made.
The town’s engineer estimated that The Colony saved over $2,000,000 in aeration basin construction costs by choosing to modify and augment their existing basins with IFAS media.
Overall plant performance has been excellent and the facility has exhibited a robust ability to challenging hydraulic conditions and loadings, especially for a high rate system. Ammonia concentrations continue to remain well below the 3 mg/l permit limit, consistently near non-detect levels.
The Colony installation was the subject of two articles in the Water Environment Technology magazine. One was a six-page article in the November 2007 issue (Vol. 11, No. 19). The most recent article was a Problem Solver in the April 2010 issue (Vol. 22, No. 4).
24 Webitat modules with 12,500 ft2 of BioWeb fixed media, totaling 300,000 ft2
BOD and TSS well below 10 mg/l, ammonia typically near non-detect levels, meeting permit