EPA water quality 



. » a,b 

 status 



Industrial BOD^ and 

 COD discharge kg/day 



Organic toxins 

 discharged 



Thermal 



Heavy metals' 



WQ'^ 



EL 

 6341^''' 4650^ 



WQ° 



249,700^ 

 Chlorinated 

 hydrocarbons 



+ 

 Lead (4000 kg/day) 

 Copper (100 kg/day) 

 Zinc (23 kg/day) 

 Chromin (309 kg/day) 

 Mercury (1 kg/day) 

 Cadmium (1.8 kg/day) 



WQ= 



61.000" 

 LAS (detergent)'' 



EL 



O 



vVQ- does not meet water quality standards even after application of effluent limitations required by the Federal Water Pollution 

 Control Act Amendments of 1972 (FWQA). EL - water quality is meeting water quality standards of the FWQA. 



''Weston 1974. 



Vermilion River from Interstate 10 Bridge to GIWW. 



Calcasieu River from Oakdale above Lake Charles to Gulf; West Fork Calcasieu River from Houston River downstream, Bayou 

 D'Inde. 



Sabine River and Sabine Lake. 



BOD = Biological oxygen demand; COD = chemical oxygen demand. 

 ^Domingue et al. 1974. 

 ''Diener 1975. 



+ Indicates heating causes significant local effects. 

 ^Environmental Protection Agency (1972). 



Nearly all discharges occur above the Vermilion Basin Boundaries. 



because they bind readily to suspended clays and are 

 rapidly sequestered in the sediments. The importance 

 of benthic organisms in the trophic structure of es- 

 tuaries (part 4) makes this behavior of heavy metal 

 pollutants particularly critical. 



Dredging of contaminated sediments suspends 

 and disperses heavy metals. When these sediments are 

 piled on spoil areas, the heavy metals are absorbed by 

 plants and thereby enter the food web, or they may 

 be carried into water bodies by runoff. 



The most heavily populated and industrialized 

 basins, Sabine and Calcasieu, are experienceing serious 

 contamination problems from heavy metals and or- 

 ganic pesticides. Although these heavy metals are, for 

 the most part, confined locally they move into the 

 food chain through benthic and nektonic feeders that 

 spread the toxins throughout the estuarine system. 



3.6 ECOLOGY OF INDIVIDUAL BASINS 



3.6.1 INTRODUCTION 



Previous chapters of this report have dealt with 

 the major processes that control basin systems on the 

 Chenier Plain. In each basin all of these processes are 

 at work, but because physiography, hydrology, and 

 socioeconomics differ, the basins are dissimilar. This 

 chapter describes the major features of each basin and 

 identifies the dominant forces shaping each one and 

 the critical problems. 



3.6.2 VERMILION BASIN 



General features. The Vermilion Basin lies on the 

 eastern edge of the Chenier Plain. The boundaries, as 

 drawn for this study, (plate IB) do not describe a 

 complete drainage unit. The basin is part of the Ver- 

 milion Bay system. Vermihon Bay is open to the east 

 and strongly influenced by westward flowing waters 

 of the Atchafalaya River (fig. 3-32). 



As circumscribed for this study, the Vermilion 

 Basin is a small unit, 1,909 km" (741 m?). Sixty per- 

 cent of this area is a large, shallow shelf in the near- 



95 



