1.0 INTRODUCTION 



One of the essential missions of the U.S. Army Corps of Engineers (US ACE) is to 

 monitor and maintain navigable waterways. Particulates originating from rivers, land 

 runoff, and atmospheric deposition accumulate in harbors and channels. Dredging is 

 required to restore the depth and width of these channels and harbors. A variety of 

 chemicals of concern (CoCs) are associated with these particulates which may pose a 

 problem for aquatic biota depending upon their concentration. One of the major classes of 

 CoCs is Poly cyclic Aromatic Hydrocarbons (PAHs). PAHs enter the environment in raw 

 (i.e., petrogenic) form as oil and fuel products or in a combusted (i.e., pyrogenic) form 

 such as stack ash and automobile exhaust. 



As part of the regulatory requirements for dredging, the US ACE must characterize 

 the quantity and type of sediments that require dredging and determine their suitability for 

 land or aquatic disposal. Although the ultimate determination of suitability rests on 

 biological effects testing (e.g., EPA/US ACE 1994, 1998), the measurable levels of CoCs 

 in surface sediments provide a critical guide for project scoping and sample location. 



Traditional analyses (e.g., for PAHs) in bottom sediments for purposes of 

 contaminant characterization typically involve sample collection, chemical extraction, and 

 instrumental analysis (e.g., UV spectrometry, gas chromatography /mass spectrometer, 

 and/or high performance liquid chromatography). These traditional methods have the 

 advantage of low analytical detection limits but are laborious, expensive, and time 

 consuming. The sheer number of sediments requiring characterization as well as the long 

 analytical time-frame and high cost per sample of chemical analysis present an increasingly 

 formidable challenge to the USACE in executing its responsibilities for characterizing 

 harbor sediments. As a result, the USACE has expressed a need for field instrumentation 

 that can be rapidly and inexpensively deployed to characterize and quantify PAH 

 concentrations in sediment. 



Science Applications International Corporation (SAIC) has developed a prototype 

 field instrument called UV-REMOTS® (UV-R) which shows great promise for the rapid 

 evaluation of PAH composition and concentration in sediment. The basic format for the 

 technology is based on the original REMOTS® sediment profile camera which produces a 

 photographic image of the sediment-water interface (to 20 cm depth) such that various 

 habitat attributes (sediment, grain-size, fabric, depth of mixture, and community structure) 

 can be ascertained. In UV-R, the analog visible (white light) camera system of REMOTS® 

 was replaced with a digital camera and UV-light source such that chemicals that fluoresce 

 under UV light can be detected and quantified (Rhoads et al. 1995). 



In this report, the results of the first substantial field deployment of UV-R in the 

 Providence River of Narragansett Bay are presented. The objectives of the study were 1) 

 to assess the operational performance characteristics of the instrument under field 



