Chlor-alkali Plant Contributes to Mercury Contamination in the Savannah River

For many years the Savannah River has suffered fish consumption warnings. While several potential sources of mercury may contribute to this contamination, the chlor-alkali facility in Augusta, which produces chlorine by electrolysis using mercury-cell technology, is a major potential contributor. To examine this possibility samples of sediment were collected from the river above and below the facility and from the channel leading to the river from the facility. Sediment mercury concentrations and sediment toxicities to amphipods were measured. Mean sediment mercury concentrations in the chlor-alkali discharge channel 62,708 +/62,216 ppb dry weight. Upstream and downstream of the chlor-alkali facility channel mean mercury concentrations of dried sediments were 24.4 +/14.7 and 46.6 +/51.2 ppb, respectively. Channel sediments and downstream river sediments were significantly toxic to amphipods as compared with river sediment samples upstream. Tissue levels of mercury in half of 34 catfish caught within 20 miles downstream of the chlor-alkali facility and 60% of the 32 bass caught in the same region of the river exceeded the 0.3 ppm that trigger a fish consumption warning. It is apparent that the extremely high mercury levels in the sediment of the outfall channel of the chloralkali plant contribute to the mercury problems in the river. Amphipod toxicity and mercury triggered fish consumption warnings are indicators that mercury is a significant problem in the Savannah River.