Ocean outfalls could solve 

 sewage disposal problems 



satisfactory. Others ha; 



ith 



piping systems are 

 problems. 



Some officials and coastal engineers contend that ocean outfalls 

 could be the answer to coastal waste disposal problems. With ocean 

 outfalls, they believe the state would come out better environmentally 

 and economically than with other proposed disposal techniques 

 such as higher levels of sewage treatment, disposing of treated 

 wastes on land or pumping wastes into natural caverns deep in the 

 earth. 



At this point, the idea of stretching the sewer line into the ocean 

 remains riddled with questions. Although outfalls have worked in 

 other places, no one is sure whether the physical conditions in North 

 Carolina's offshore zone are suitable for ocean outfalls. Before deci- 

 sions regarding outfalls can be made, more information on the 

 physical characteristics, on wares and currents and the mixing of 

 waters in the state's offshore area is needed. 



Already North Carolina's Department of Administration has 

 initiated a comprehensive examination of the environmental and 

 economic costs of ocean outfalls in North Carolina. The study, 

 organized under the direction of Dr. Ernie Carl of the N. C. Office 

 of State Planning, will be the basis for state policy on ocean sewage 

 disposal. 



According to Carl, the study has short and long term aspects. In 

 the short term the goal is to bring together information that is 

 already available on the state's offshore environment and to relate 

 data from other states' outfall systems to North Carolina's specific 

 needs. Dr. Leonard J. Pietrafesa, North Carolina State University 

 physical oceanographer working with UNC Sea Grant support, has 

 contributed substantially to this part of the study which should be 

 complete later this spring. 



In the long run. study organizers hope to compile more complete 

 nowledge about the state's entire offshore area through additional 

 search. Eventually state planners hope to be able to predict the 

 nomic effect of outfalls at any location on commercial fishing, 

 ellfishing, land values and community growth. 

 Research to learn more about North Carolina's ocean currents 

 nd water circulation patterns in an offshore area from Morehead 

 ity to the state's southern boundary is already underway. Under a 

 grant from the UNC Sea Grant Program, North Carolina State Uni- 

 ;rsity physical oceanographers Drs. L. J. Pietrafesa, C. E. Knowles 

 id C. C. Tung are studying to determine where wastes pumped 

 (through the outfalls would eventually be transported. In some other 

 sewage discharged through outfalls has washed back onto 

 hes because current action was not fully understood before pipes 

 s stationed. Data from the Sea Grant-supported study will be fed 

 the computer, with the long-term goal being to predict the 

 1 of effluents pumped i nto the sea. 

 Ocean outfalls could provide an answer for coastal communities 

 cing increasing sewage problems, at least until man learns to 

 ~ iently and safely recycle wastewaters for their eventual re-use. 

 before we can safely rely on the ocean as dumping grounds. 

 ; of questions need answers. Hopefully, they won't be long in 



Life has become alot more compli- 

 cated over the yean, especially on 

 the coast. In crowded areas, sandy 

 beach soils have become saturated 

 with man's wastes and water sup- 

 plies are threatened with contami- 

 nation. One way to handle the in- 

 creased waste problem may be to 

 pipe treated sewage into the sea. 



Getting rid of wastes: 



A review of the alternatives 



We've tried septic tanks and municipal 

 sewage treatment plants to handle the 

 wastes we generate in the coastal area. In 

 North Carolina, neither has been a rousing 

 success environmentally. 



There are yet other methods that could 

 be used to rid the coastal zone of wastes. 

 But they too seem to have problems. 



Speakers at the Southeastern Conference 

 on Water Supply and Wastewater in Coast- 

 al Areas surveyed some proposed disposal 

 techniques. 



In his summary remarks, Dr. B. J. Cope- 

 land, director of the UNC Sea Grant Pro- 

 gram and professor of zoology at North 

 Carolina State University, gave an over- 

 view of disposal techniques discussed and 

 cited potential environmental problems 

 associated with each. Following is a run- 

 down of disposal techniques, problems as- 

 sociated with and information needed to 

 make wise decisions regarding each, as 

 spoken to by Dr. Copeland. 



Septic tanks 



Widely used in North Carolina's coastal 

 zone. 



Problems: Seepage of nutrients, organ- 

 ics, poisons and disease organisms into 

 nearby surface and sub-surface waters, up- 

 setting the use of existing shallow ground- 

 water for water supply. Evidence shows 

 that disease organisms from septic tanks 

 have reached estuarine waters resulting 

 in their closing for commercial shellfishing. 



Needed information: Before more septic 

 tanks are permitted there is need for com- 

 plete soil testing and hydrology data for 

 realistic siting and sizing. 



Conventional treatment plants 



Duringthe very near future, conventional 

 treatment facilities and the disposal of 

 treated wastes in nearby areas seems to be 

 the most available disposal solution. 



Problems: Even with sophisticated treat- 

 ments, effluents containing some nutrients 

 and pathogens will be disposed into sounds 

 and estuaries. This has a potentially dam- 

 aging impact on productive estuarine areas. 



Needed information: Need to develop an 

 economical means of high level or other 

 treatment to minimize the impact of efflu- 

 ents in nearby coastal waters. 



Land disposal 



On-land disposal of waste may be an 

 economical solution and at the same time 

 provide fertilizers. This technique has 

 proven to be a good means of disposing of 

 animal wastes in the state's Piedmont re- 

 gion. 



Problems: Nutrients, trace metals and 

 pathogens in the sewage flow through the 

 soil to groundwaters and then into surface 

 waters. Holding ponds, apparently neces- 

 sary for land disposal pretreatment, are a 

 potential hazard in areas with high water 

 tables. Availability of enough land areas 

 for effective disposal on the barrier islands 

 is another problem. 



Needed information: Basic knowledge of 

 soil-water characteristics of coastal soils 

 should be completed and the rates of dis- 

 posal on land need to be equated with the 

 lands' capacity to absorb and hold waste- 

 water. Additional information needs to be 

 gathered on the use of vegetative buffers 

 between land areas where waste is disposed 

 and nearby waters. 



Deep well injection 



Disposal by this method involves pump- 

 ing wastes deep into the earth. It does not 

 appear suitable for coastal use. 



Problems: Contamination of ground- 

 water supplies could result since it is 

 difficult to determine the fate of the in- 

 jected materials and leakage of these into 

 the sounds and ocean is possible. 



Ocean outfalls 



A technique of collecting, treating and 

 disposing of domestic waste by piping it 

 into the ocean. 



Problems: Outfalls not properly designed 

 and located could result in sewage washing 

 back onto beaches. A more subtle effect of 

 outfalls is that they could deprive estuaries 

 of varying amounts of needed freshwater. 

 Instead of going into the estuaries, fresh- 

 water channeled through outfalls winds up 

 in the sea. 



Needed information: Currents and water 

 mixing patterns off the North Carolina 

 coast should be plotted before outfalls are 

 permitted. Design criteria must be col- 

 lected to enable coupling of the outfall with 

 environmental conditions and to prevent 

 localization of sludge at the outfall site. 



