Cooperative Extension Service

Large and Package System

Rob Crawford
Dare County Environmental Health
PO Box 1000
Manteo, NC 27954.

The outer banks presents some unique problems when it comes to wastewater treatment and disposal systems. Two of the challenges we face on the barrier islands are extreme fluctuation in flows due to the nature of the vacation industry and the need to treat and dispose of high strength waste (generated by restaurants) in smaller areas. Two case studies will be presented to demonstrate how we met these challenges.

First case is the Barrier Island time share development in Kitty Hawk, North Carolina. The development is a resort community that will have a design flow of 120,000 gallons per day at build out. The problems this project faces are the fluctuating flows from summer to winter and the increasing flows as the project grows with the addition of each phase. The project has now completed three phases of construction and the flows will be steady through the summer but will drop once labor day arrives. There will be weeks in the off seasons (such as the Thanksgiving day week) where flows will increase significantly. The operator must make operational adjustments to the treatment process that will account for the increase flow and result in discharges that remain compliant.

In the design of the treatment plant the engineer had to plan for the fluctuating flows and the increasing flows that were predicted as the project grows. The treatment process was designed with three different size aeration basins that give the operator many options for treating the increasing and decreasing flows.

The second case is the Outer Banks Brewing Station project in Kill Devil Hills, North Carolina. This project consist of a 200 seat restaurant with a micro brewery. The design flow for this system is 10,000 gallons per day. The treatment process was developed based on the Virginia Initiative Plant (VIP) in Norfolk, Virginia. This plant is design to treat a waste stream from the brewery which consist of a 5 day BOD predicted to be as high as 3,300 ppm and a total suspended solids concentration of 1,100 ppm and the typical restaurant waste stream of 400 ppm of BOD5 and TSS. The treatment plant is designed to produce an effluent stream with a 10\10\15 discharge in order to reduce the drain field size.

I will discuss the construction and components of each treatment plant. The treatment plant operations and the results of the testing of the final effluent.

Please address any questions to Dr. David Lindbo.

This page created by
Roland O. Coburn, Research Technician I on 2/18/03.

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