225 



Vessels iischarging sludge will oe sufficiently separated 

 from vessels discharging chemical wastes to prevent the 

 two types of wastes from mixing. 



Key constituents of the sludge will be routinely analyzed 

 in barge samples at a frequency to be determined by EPA on 

 a case-by-case basis, but sufficient to evaluate 

 accurately mass loading at the site. 



Routine bioassays will be performed on sludge samples 

 using aopropriate sensitive marine organisms" (EPA, 1980, 

 p.xxiii emphasis addea). 



The technical aata generated since 1980 do not significantly improve our 

 understanding, or the preaictabil ity, of any possible impacts from con- 

 tinuous dumping of large quantities of sewage sludge at the 106-Mile 

 Site, although the weight cf evidence continues to indicate that such 

 dumping would not be harmful to human health or the environment of the 

 106-Mile Site. The ability to confidently predict oossible impacts at 

 the 106-Mile Site is limited because of two factors. First, only very 

 small quantities of an atypical (primary) sewage sludge have been dumped 

 at the 106-Mile Site, this dumping has not been continuous, and scien- 

 tific studies have been limited. Second, information cannot be extrapo- 

 lated from studies at other dumpsites since sewage sludge has not been 

 dumped at any other deep ocean site similar to the 106-Mile location. 

 These considerations, combined with EPA and National Oceanic and Atmos- 

 Dheric Administration (NOAA) assessments that stopping sewage sludge 

 dumping at the 12-Mile Site will not yield any significant human health 

 or environmental benefit, support the 1980 FEIS approach to designation 

 of the 106-M1le Site: the 106-Mile Site could be safely designated for 

 sewage sludge dumping, but sewage sludge currently dumped at the 12-Mile 

 Site should not be transferred to the 106-Mile Site unless future data 

 show a critical need to reduce the quantities of sewage sludge dumped at 

 the 12-Mile Site. Further, any dumping of sewage sludge at the 106-Mile 

 Site should be phased in over a number of years with adequate study of 

 the effects of continuous dumping and of any cumulative effects as the 

 rate of dumping increases. 



"^he proposed designation of the site for only five years shows justifi- 

 able caution in view of the paucity of knowledge concerning the effects 

 of sewage sludge dumping at the 106-Mile Site. However, a more appropri- 

 ate approach, supported by the findings of the 1980 FEIS and subsequent 

 tecnnical assessments, would be *"0 designate the 106-Mile Site for sewage 

 sludge dumping without a time limitation, but with a slow phase-in period 

 required subsequent to initiation of any use of the site for sewage 

 sludge. Such a phase-in would allow adequate monitoring and assessment 

 as prescribed in the periodic site evaluation and assessment procedures 

 under 40 CFR Sections 228.10 and 228.11, and would allow the determina- 

 tion as to whether this designation should be continued into future years 

 to be based upon scientific findings from these studies. 



The criteria that must be addressed by EPA for site selection are found 

 at 40 CFR 228.6. These criteria, as they apply to the 106-Mile Site, are 

 fully addressed in this report. 



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