were held in the laboratory and acclimated for 2 to 10 days before testing. Test sediments were press- 

 sieved through a 2.0 mm mesh sieve and homogenized. Test chambers were quart-size glass canning 

 jars with inverted glass dishes as covers. Two hundred of sediments were added to each test chamber 

 and covered with 600 mL of laboratory seawater. Aeration was continuous via a glass tube, lighting 

 was continuous during the 10-day static exposures, and temperatures were maintained at 20°C. Five 

 replicate tests were performed with the sediments from each station and the control, using 20 animals 

 in each test chamber. Exposure chambers were checked daily and the number of individuals that were 

 dead, or moribund, on the sediment surface, and/or on the water surface were recorded. Dead animals 

 were removed daily Amphipods were considered to be dead when they did not respond to a gentle 

 prod with a glass rod. 



Six samples collected during Phase 2 were suspected to be highly contaminated with dioxins, and, 

 therefore hazardous. The amphipod survival tests of these samples were performed by Aqua Survey, 

 Inc., using the same ASTM (1990) protocols. The amphipods were obtained from East Coast Amphi- 

 pod Co., Narragansett, RI (from the same site used by SAIC) and acclimated to test water for 96 hours. 



The bivalve larvae test with Mulinia lateralis generally followed the protocols of the U.S. EPA/ACOE 

 (1991) with some modifications. Adult male and female clams were induced to spawn by temperature 

 manipulation. Egg stocks of about 1,200 eggs per mL and sperm stocks of about 4 million sperm per 

 mL were prepared. To prepare the embryo stock, 1 00 uL of sperm stock was added to every mL of egg 

 stock and fertilization was allowed to proceed for about 35 min. The embryos were then retained on a 

 10 «m screen, and then resuspended. Next, 0.75 mL of embryo stock was added to vials containing 15 

 mL of sample or control. Initial embryo counts were performed on the contents of six vials containing 

 15 mL of seawater. Elutriates were prepared by adding 100 g (wet wt.) of homogenized sediment to 

 500 mL of laboratory seawater in clean glass jars. The elutriates were mixed for 30 min. using heavy 

 aeration with manual stirring every 10 min. After 30 min., the suspensions were allowed to settle for at 

 least one hour. At least 80 mL of supernatant was gently poured into a 0.4 «m filter housing and 

 vacuum filtered until there was enough filtered sample for 5 replicates of 15 mL each. Static test 

 exposures of the liquid phase samples were conducted for 48 hours at 22°C. After 48 hours the tests 

 were terminated by adding 0.75 mL of 50% buffered formalin to each vial. The total number of em- 

 bryos and the number of normal-appearing embryos were counted. 



The Microtox tm tests followed an adaptation of the protocols prepared by U.S. EPA Region 10 (1990). 

 The tests were performed with organic extracts of the sediments. Three grams (wet wt.) of each sedi- 

 ment sample were weighed into a 100 mL Pyrex centrifuge tube with a Teflon lined top. Each sample 

 was centrifuged for 10 min. at 1,750 RPM and the water discarded. Fifteen grams of sodium sulfate 

 was mixed in, then 50 mL of dichloromethane (DCM) was added and mixed. The samples were shaken 

 overnight; centrifugation was repeated; and the supernatant was collected in a 200 mL flask. The 

 extraction steps were repeated twice and the extract solutions collected in a flask. The solutions were 

 evaporated under nitrogen to a volume of about one mL. Undenatured ethanol was added and the 

 volumes reduced to just below one mL in a 100°C water bath. The final volumes were adjusted to 1 mL 

 with undenatured ethanol. An ethanol reagent blank was prepared as above but contained no sediment. 

 Lyophilized bacteria (Photobacterium phosphoreum) were reconstituted with 1 mL of deionized water 

 and placed in a Microtox tm cuvette at 4°C. Tests were performed with 10-fold serial dilutions (repre- 

 senting 10, 1.0, 0.1, and 0.01 uL of sediment extract) prepared in seawater. Blanks were prepared at the 

 same concentrations by similar dilutions of the ethanol reagent blank. All dilutions were conducted in 

 test cuvettes in temperature-controlled incubation wells. Reconstituted bacteria were added to each at 

 30-sec. intervals and mixed well to initiate the tests. Exactly five minutes later, light emission was 



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