One community's 

 disposal dilemma 



Wrightsville Beach officials took major 

 steps to deal with their town's growing 

 waste disposal problem on a community- 

 wide scale in the mid-60s. 



Septic tanks, having multiplied over the 

 years with an ever- increasing influx of 

 residents and vacationers, were overtaxing 

 the ability of the sandy beach soil to absorb 

 increasing amounts of sewage. 



So the town got together and built a 

 sewage treatment plant. Treated waste- 

 water from the plant is discharged into 

 Shell Island Sound, estuarine waters run- 

 ning between the island community and 

 the mainland. 



By 1972, town officials saw the writing 

 on the wall: Growth was outpacing the 

 treatment plant's capacity to process 

 wastes. Changes in permit-letting rules and 

 agencies concerned with water quality 

 brought plans for plant expansion and im- 

 provement to a standstill. 



Today, the treatment plant is operating 

 at capacity, yet the glistening waters and 

 sands of Wrightsville Beach attract more 

 people every year. Shellfishing is no longer 

 permitted in waters where the town's sew- 

 age effluents are pumped. Although the 

 treatment plant can't be blamed as the sole 

 polluter, many are convinced that its dis- 

 charge largely contributed to the closing 

 of shellfishing waters. 



Under the Federal Water Pollution Con- 

 trol Act. municipalities may obtain federal 

 funds to upgrade sewage treatment facili- 

 ties. A plan for the design of such facilities 

 and their impact on the environment must 

 be approved by a state environmental board 

 and the Environmental Protection Agency. 



Wrightsville officials have taken steps to 

 find solutions to the waste disposal problem 

 and to obtain federal funds for upgrading 

 facilities. They have submitted a plan to 

 the state proposing eight alternative means 

 of waste disposal. The plan, designed to 

 fulfill 201 facilities planning requirements 

 under the Federal Water Pollution Control 

 Act, names ocean outfalls as the most eco- 

 nomical and environmentally safe alterna- 

 tive. As of yet, the plan has not been 

 approved. 



A historic look 



at coastal waste disposal 



State and local officials are casting an eye 

 toward the Atlantic as the next dumping grounds 

 for man's wastes. 



What has led to serious consideration of piping 

 treated sewage into the sea from coastal areas? 



Col. Paul Denison, principal engineer of Henry 

 von Oesen and Associates, Inc., consulting engi- 

 neers in Wilmington, provided some background 

 on coastal sewage disposal in remarks to the South- 

 eastern Conference on Water Supply and Waste- 

 water in Coastal Areas, held in Wrightsville Beach 

 in early April. 



"Historically, as man began to occupy the 

 coastal margin, he simply drilled shallow wells in 

 the surficial sands to supply water for drinking 

 and other purposes," Denison said. "At the same 

 time, he discharged his sewage wastes back into 

 the same surficial sands or land areas, using con- 

 ventional septic tanks or even more primitive dis- 

 posal means," Denison explained. 



Before development boomed, the lands could 

 supply man with ample fresh water and could 

 absorb his wastes, Denison continued. But as more 

 people began using the coastal zone, the lands' 



"The specific problem that we haven't really 

 faced up to is the one of domestic wastewater 

 treatment and disposal in the beach and estuarine 

 areas." — Col. Denison. 



ability to furnish man's needs was increasingly 

 taxed. 



To supply growing demands for fresh water, 

 communities turned to municipal water supply 

 and distribution systems. Denison continued. But 

 sandy coastal soils can produce only limited quan- 

 tities of fresh water and some coastal community 

 and private systems are finding that they may 

 soon be unable to supply needed quantities of 

 water. 



Accordingto Denison, the problem of wastewater 

 disposal in the coastal area is even more challeng- 

 ing than that of water supply. 



"The specific problem that we haven't really 

 faced up to is the one of domestic wastewater treat- 

 ment and disposal in the beach and estuarine 

 areas," Denison charged. Commercial and indus- 

 trial wastes do present disposal problems but in- 

 dustry is being required to meet continuously 

 increasing controls on effluent discharge: 



Growth and development have resulted in ever- 

 increasing domestic sewage discharges into the 

 surface sands and soils bordering on coastal waters, 

 (See "Soils," page 6) 



You can save fuel by slowing boat speed 



We goofed. When we published this graph on 

 fuel savings in the February Newsletter, we failed 

 to notice that the propeller rpm line was drawn in 

 the wrong place. Here, with our apologies, is the 

 corrected version of the graph and directions on 

 how to use it. 



The graph is designed to show how you can save 

 fuel by reducing the speed of your boat. Most of 

 you know this, but this graph allows a quick 

 estimate of the possible fuel savings and the 

 amount of time that must be sacrificed at lower 

 speeds. 



Here's an example of how the graph works: 

 assume a boat is designed to make 10 knots top 

 speed (100 percent); if the boat is operated at 8 

 knots (80 percent of its top design speed), it would 

 consume only 50 percent of the fuel it would use at 

 10 knots and run at 20 percent lower rpm, as shown 

 by the dotted lines on the graph. 



To read the graph, choose on the bottom line the 

 percentage of design speed to be used and run a 

 perpendicular line through both the propeller rpm 

 and fuel consumption curves. From the points 

 where this vertical line intersects these curves, 

 run horizontal lines at right angles and read the 

 percent of fuel reduction and rpm on the left-hand 

 scale. 



Boat speed as percentage of design speed 



Provided by the Marine Advisory Service at the Massa- 

 chusetts Institute of Technology. Cambridge 



Soils can't absorb wastes 



(Continued from jtage 5) 

 Denison said. Discharge has increased to a point 

 where the capacities of these soils to assimilate the 

 wastes "have been taxed beyond tolerable limits," 

 he added. 



In addition to presenting potentially serious 

 health and sanitation problems, Denison said that 

 evidence shows that excessive waste discharges 

 into coastal soils are beginning to enter and ad- 



versely affect nearby estuarine waters. 



In Denison's opinion, which he bases on exten- 

 sive study of the problem in coastal North Caro- 

 lina, ocean outfalls offer the most viable solution 

 to the problem of waste disposal in the coastal 

 zone. "In my opinion, he concluded, "adequate 

 and optimum protection of our environment in 

 North Carolina is being delayed due to lack of 

 guidelines and initiatives (by the State) on the 

 important question of ocean outfalls." 



University of North Carolina 

 Sea Grant Program 

 1235 Burlington Laboratories 

 North Carolina State University 

 Raleigh, N. C, 27607 



