271 



- 15 - 



QUESTION: 



a. How often are contaminated dredged material disposal sites monitored? 



b. What is examined as part of the monitoring process? 

 ANSWER: 



a. Monitoring to evaluate impacts in the marine environment is resource 

 intensive and time-consuming. The frequency of monitoring at any ocean 

 disposal site is based on a number of site specific factors, of which 

 contamination is one. Other factors include, but are not limited to, the 

 frequency, volume, and characteristics of disposed material, the sensitivity 

 of the environment around the disposal site, and the availability of 

 resources. For example, monitoring may be important at a site, even if the 

 material is not contaminated, if the movement of the material could cause 

 physical impacts to near-by sensitive resources. For the period from 1987 

 to 1990, EPA conducted surveys at 27 of the 110 ocean dump sites. This 

 figure does not include monitoring which has been conducted by the Army 

 Corps of Engineers. 



b. Monitoring information is used to verify that permit conditions are met and 

 to determine if the conditions set by the permit are sufficient to prevent 

 adverse impacts. Monitoring disposal sites used by multiple dumpers is 

 especially important in determining whether the cumulative impacts are 

 acceptable. 40 CFR 228 contains considerable detail as to what may be 

 required in a monitoring program. 



In general, the primary purpose of monitoring is to evaluate the impact of 

 disposal on the marine environment by referencing the monitoring results to 

 a set of baseline conditions. The most common measurements collected 

 during monitoring programs include water depths, water quality, distribution 

 of disposed material in the water column and on the bottom, long-term 

 resuspension and movement of deposited material from the disposal site, 

 and movement of contaminants from the deposited material to aquatic 

 organisms. Project specific monitoring programs are tailored to the predicted 

 pathways and impacts of the dumping, based on the type of material and 

 characteristics of the disposal site. 



