Howard County Public Schools WWTP MBR Upgrade

GMB was retained by the Howard County Public School System to provide on-call architectural and engineering services related to wastewater treatment and disposal through a qualifications-based selection process,

GMB’s first assignment was to design a new nutrient treatment system to replace the current on-site septic systems. Previously, Howard County Public Schools had installed sequencing batch reactor (SBR) treatment systems at four other school facilities. However, as Maryland Department of the Environment continues to reduce allowable nutrient discharges from on-site systems, a more advanced treatment scheme would be needed to meet stricter groundwater permit limits

As a result, GMB recommended that Howard County Public Schools construct a Membrane Bio-Reactor (MBR) treatment system at their Triadelphia Ridge Elementary and Folly Quarter Middle Schools instead of the standard SBR.

Not only do MBR systems provide a higher level of nutrient treatment, but they also provide more reliable treatment. The membrane filter provides a physical barrier between the biomass and the final effluent. The two-stage activated sludge system associated with the MBR is a proven nutrient treatment technology which has been applied in Maryland treatment facilities for more than twenty-five years. High MLSS concentrations associated with an MBR make the process more resilient and easily adaptable to the seasonal fluctuations associated with summer breaks.

The proposed MBR will be able to reduce effluent nutrient levels below current permit limitations and would provide the flexibility needed to accommodate future school expansion or future reductions in allowable nutrient discharges. The MBR also protects surrounding groundwater supplies by reducing effluent Total Nitrogen concentrations below drinking water standards.

Most components of the new treatment process (tanks, pumps, membranes, and process controls) will be located above ground and inside a climate-controlled building for ease of operation and easy access for maintenance.

Services Provided:  Alternatives Comparison, Cost Estimating, MBR Process Design, Construction Drawings, Electrical Design, Bidding, Construction Administration and Full-Time Inspection.