among the nine DAMOS sites; the 

 tiered monitoring schemes presented 

 in the sections to follow apply only to 

 non-dispersive sites. At non-dispersive 

 (containment) sites, disposed sediment 

 accumulates on the bottom and 

 eventually will reach a depth at which 

 either the deposit is subjected to 

 erosive forces, depths become a hazard 

 to navigation, or the volume of 

 sediment disposed at the site reaches 

 the physical limits of the site's 

 capacity. At dispersive sites, the 

 objective is to dispose of sediment 

 with the intention that it will be 

 transported away from the site without 

 long-term accumulation and without 

 adverse environmental impacts. 

 Tiered monitoring schemes for 

 dispersive sites (i.e., model 

 verification) have not been developed 

 as of this writing. 



Managing the physical aspects of 

 dredged material disposal in order to 

 optimize site use (including conduct of 

 capping operations where appropriate 

 and selection of the precise disposal 

 point(s) within the site) requires that 

 monitoring be conducted to determine 

 the lateral distribution and elevations 

 of disposed sediment mounds, to 

 confirm that capping operations 

 conform to project specifications, and 

 to allow detection of deviations from 

 expected disposed sediment behavior 

 (including stability of capped mounds). 

 Information from monitoring then can 

 be used to modify disposal operations 

 as conditions warrant. This may 

 include modifying disposal techniques, 

 relocation of the disposal point within 

 the site boundaries, creation of "bowls" 

 to provide areas for accepting and 

 capping contaminated material, or 



17 



addressing a need to repair portions of 

 eroded caps. 



The fourth objective is the key issue 

 with which we are dealing in this 

 document. As mentioned previously, 

 open-water disposal is regulated under 

 Section 404 of the Clean Water Act and 

 Section 103 of the Marine Protection, 

 Research, and Sanctuaries Act. The 

 language of these laws regarding 

 marine environmental impacts is very 

 general and in essence states that 

 disposal must not cause unreasonable 

 adverse impacts. Compliance with 

 environmental laws and regulations 

 relating to the disposal of dredged 

 sediment requires that disposal 

 activities, including the actual 

 presence of dredged sediment in the 

 region, do not result in adverse effects 

 on marine fisheries and other valuable 

 marine resources. How we get from 

 these generally stated but critically 

 important laws and regulations to the 

 specifications for a well-designed 

 regional monitoring program is the 

 challenge that faced the DAMOS TAC. 



3 2 Background Assumptions 



At the initial TAC meetings, a 

 philosophy for ecological monitoring 

 was constructed by listing assumptions 

 on which this general philosophy was 

 based. These assumptions also 

 provided a basis for determining if 

 specific proposals for monitoring in 

 the project area would be considered 

 seriously as elements of the final 

 Ecological Monitoring Plan (EMP). The 

 assumptions were as follows: 



(a) Ecological processes are studied 

 most effectively by recognizing the 



An Integrated, Tiered Approach to Monitoring and Management of Dredged Material Disposal Sites 



