Dare County May Be 

 N.C. Test Ground 



Dare County may be the first testing grounds 

 for an ocean outfall' in North Carolina. Two years 

 ago the Dare County Board of Commissioners be- 

 gan grappling in earnest with plans for a munici- 

 pal sewage treatment plant for the larger commu- 

 nities in the county. In October 1976 a proposal to 

 study the possibility of an outfall in the county was 

 completed by Henry von Oesen Associates, a Wil- 

 mington engineering firm. 



William E. Burnett, one of the firm's engineers, 

 is convinced that Dare County is one of the best 

 sites for an outfall in North Carolina. "There is no 

 other way of disposing of the wastewater in Dare 

 County that is environmentally sound and cost 

 effective," he said. 



The engineering firm's study plan has now 

 passed the approval of the state's reviewing 

 agency, the Division of Environmental Manage- 

 ment of the Department of Natural and Economic 

 Resources. Dare County officials are waiting for 

 EPA approval before they proceed with the study. 

 Once the final study is complete, approval of both 

 agencies will be required before actual construc- 

 tion is begun. 



The preliminary plan calls for construction of 

 an outfall which would ultimately serve Kitty 

 Hawk, Nags Head, Kill Devil Hills, Manteo and 

 the Wanchese Harbor fisheries complex. Accord- 

 ing to Burnett, the outfall would be built either in 

 Nags Head or Kill Devil Hills. The plan is based 

 on a projected flow of 3.5 million gallons of treated 

 wastewater per day for the year 1990. The outfall 

 pipe would reach out into the ocean about a mile 

 and discharge would be into 45 or 50 feet of water. 



The tentative plan also proposes that domestic 

 sewage be treated to a secondary level at a treat- 

 ment plant located on about 15 acres of land near 

 Kill Devil Hills. Secondary treatment removes 

 about 90 percent of the suspended solids from the 

 wastewater and the majority (but not all) of the 

 bacteria and viruses. 



In selecting an ocean outfall as the most promis- 

 ing plan for Dare County, the engineering firm 

 rejected three other alternatives commonly used in 

 the United States. One possibility would be to dis- 

 charge the wastewater from a regional treatment 

 plant into the estuarine waters of the Currituck, 

 Albemarle or Pamlico Sounds. The water in those 

 areas, Burnett points out, is shallow. Disposal of 

 sewage into the sounds could eventually upset the 

 balance of plant and animal life in the estuaries. 



Joe Stokes, Dare County sanitarian 



Burnett also fears that the discharge might aggra- 

 vate the problem of milfoil, an aquatic plant whose 

 rapid growth has clogged parts of Currituck 

 Sound. And, finally, Burnett was concerned that 

 pollution of the estuaries might mean the closing 

 of more of the state's shellfishing waters. 



A second alternative, land disposal, would in- 

 volve spraying treated wastewater over about 900 

 acres of land. Peat soils and a water table that is 

 almost at the soil's surface make the land on the 

 mainland of Dare County unacceptable. About 85 

 percent of the land on Dare County's Outer Banks 

 is environmentally sensitive park land. Burnett 

 was unable to find a suitable area large enough for 

 land disposal on the islands. He felt that using 

 several smaller plots would have made the cost of 

 the project prohibitive. 



A third option which has been unsuccessfully 

 tried once in North Carolina is deep well injection. 

 It requires piping treated wastewater into wells 

 drilled into the earth's surface. Since 1973, North 

 Carolina law has prohibited deep well injection. 

 "You really don't know what happens to the efflu- 

 ent and whether it might mix with drinking 

 water," said Burnett. 



Scientists tackle tough questions 



Several Sea Grant researchers are among the 

 North Carolina scientists who are taking a look at 

 many of the tough technical questions that need to 

 be answered about ocean outfalls. 



Sea Grant is funding three projects this year 

 which are related to the issues of ocean outfalls. 

 In a project supported by the EPA and the North 

 Carolina Department of Natural and Economic 

 Resources (through the Water Resources Re- 

 search Institute), researchers will be looking at 

 the options for water management in coastal North 

 Carolina. One of the aspects of the study will be an 

 analysis of the possibility of ocean disposal of 

 wastewater. Studies will be made of population 

 trends, available water resources, water require- 

 ments, and laws. Researchers will also be taking 

 a look at the sociological and political problems 

 involved with water management. The study will 

 concentrate on the Dare County Outer Banks and 

 Morehead City-Carteret County areas. 



One other project now in the works is a com- 

 prehensive study funded by the Coastal Plains Re- 



gional Commission (CPRC) and the Department 

 of Administration's Office of Marine Affairs 

 (OMA). The two year project, which got underway 

 in January, is a landmark study of the East coast. 

 Scientists working on the project will be taking a 

 general look at the feasibility of placing an ocean 

 outfall off the North Carolina coast. They will 

 study the engineering of outfalls and their poten- 

 tial effect on marine life and public health. 



One of the first questions to be answered about 

 outfalls is how the sewage effluent will be mixed 

 in the ocean waters and where it will go. With the 

 aid of Sea Grant funding, Dr. L. J. Pietrafesa of 

 NCSU has been studying the circulation patterns 

 of the North Carolina continental shelf for the 

 past three years. Pietrafesa has stationed com- 

 plex moorings 40 to 150 miles out in the ocean to 

 collect data on water temperature, salinity, cur- 

 rents and winds. He is doing intensive studies of 

 the circulation in Onslow, Raleigh and Long Bays. 



Results of Pietrafesa's 1975 study of Onslow 

 (See "Circulation, design," p. 5) 



CAPE' 

 -LOOKOUT 



MOORING 

 A 



KILOMETERS 



33°30' 



I 



"i-.v77»30' 



Two mooring locations being used in Pietrafesa's circulation studies of Onslow Bay 



