Membrane Bioreactor for Retirement Community

Dynatec provided a membrane bioreactor system to treat wastewater from a Retirement community. The system was designed for BOD and nitrogen removal.

undefinedGlen Meadows

The facility:

Glen Meadows is a retirement community located next to Gunpowder Falls State Park in north-central Maryland’s open country.  The community has Independent Living, Assisted Living, and Skilled Nursing and Rehabilitation facilities.

The problem:

The facility has grown significantly over the years. At first, a septic system satisfied the needs for wastewater treatment. Subsequently, a second septic system was added, and this was followed by a recirculated sand-bed system. The discharge permit requirements were consistently not met and the sand bed system created odors and flying pests.  Residents were unable to use the grounds near the wastewater treatment because of odors and flies.

The owners reached out for assistance in designing a facility that would answer the requirements, i.e. that the present and future discharge criteria would be met, that the system would not create nuisance odors, and that is would be easily expandable for future planned expansion of the facility.

Technologies Considered:

Some other technologies were considered, such as a conventional SBR system, MBBR, and submerged MBR systems, however, none were considered to answer all of the requirements as well as the DynaLift™ MBR system.

The solution:

A building was erected both to house the new treatment equipment, and to provide storage for landscaping and other equipment. The building was designed to have the appearance of a horse-barn, in keeping the local environment. The existing septic tanks were retained for flow equalization and air was added for mixing. The existing treated water storage was retained with a view to using the treated water in future for irrigation. No other in-ground work was required, other than trenching for connecting pipework.

Dynatec used above-ground HDPE tanks for the reaction tanks, thereby proving the owner with considerable savings over the possible alternatives.

The new system was designed for the treatment of 50,000 gals per day, with additional capacity of an additional 50,000 gallons per day treatment capacity available at reasonable cost and without any disturbance to the original installation.

The Dynatec design met all the treatment goals in a small cost effective footprint.  The system is designed for nitrification and denitrification of the wastewater in addition to BOD and TSS removal.


The system has operated since 2007 and has met the discharge permit requirements at all times.  The owner is very pleased with the system and its operation, which meets or exceeds all the design goals.  Additionally, the retirement community residents now enjoy activities such as gardening and walking in areas that were unusable with the old system.

It should be noted that these results are achieved without the addition of supplemental carbon. This is not added, since at present, total nitrogen values are not required to be noted under the existing permit.

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