surfaces and altered water drainage may reduce the amount of natural 

 recharge that would replenish groundwater. At the same time, overpumping of 

 groundwater supplies near the shore can lead to the drying out of wetlands 

 and salt intrusion into aquifers. Solutions lie in reducing impervious 

 surfacing and in controlling well sites. 



4.10 SEWAGE SYSTEMS 



Any increase in population caused by OCS expansion will add to a 

 community's sewage load, increasing the amount of effluent produced. Many 

 coastal water basins receive effluent from sewage plants that contain 

 greater concentrations of nutrients, organic matter, toxic substances, and 

 pathogenic organisms than the basin can assimilate. In low-lying areas with 

 naturally high water tables, liquid waste from septic systems may saturate 

 the soil and cause overflow. This pollution potential from septic tanks is 

 intensified in flood-prone areas, where high tides and storms periodically 

 saturate the soils. The problem can be solved by avoiding the use of septic 

 tanks in low-lying areas and by providing proper levels of sewage treatment 

 and disposal . 



4.11 OVERLAND TRANSMISSION SYSTEMS 



All aspects of community growth involve transmission systems for 

 electricity, water, sewage, power, and gas. A small OCS-related facility 

 might not be accompanied by any significant secondary expansion in these 

 systems, but a large refinery might require expansion. There are potential 

 problems with transmission systems in the alignment, construction, and, to 

 a lesser extent, in leakage of transmission systems. Like roadways, these 

 systems may obliterate vital ecological areas or degrade them during 

 clearing, excavation, or installation. For example, wetlands have been 

 favorite locations for sewage gravity mains and pipe crossings. A 

 solution is to align routes to avoid critical and vital areas and use 

 appropriate safeguards to prevent ecological disruption during construction. 



4.12 STORM WATER SYSTEMS 



Increased community facilities creates additional demand for storm 

 sewers because of the build-up of impervious surfaces (roads, parking 

 areas, and roof-tops) in the community. Rainfall in urbanized areas is 

 considered a nuisance and a hazard. The resulting runoff is removed as 

 quickly as possible by construction of storm drains and sewers. In the 

 coastal zone, standard practice has been to pipe runoff directly into 

 surface waters with little or no treatment. Natural subsurface purification 

 is therefore bypassed by channeling contaminants directly into a water body. 

 Runoff may have higher biochemical oxygen demands (BOD) and greater 

 concentrations of various pollutants than domestic sewage. Problem 

 resolution may lie in appropriate detention and treatment of storm waters 

 and, particularly, in the use of alternative, more natural, drainage 

 systems. 



41 



