Quality of water in the Pearl River, Jackson to Byram, Mississippi, September 21-22, 1976

The Pearl River in Mississippi, entering the study reach at site 1 at Jackson, was generally higher in dissolved-oxygen concentrations and lower in dissolved-solids, nutrients, and biochemical oxygen demands than at site 13 at Byram 11.8 miles downstream of site 1 and about 11 river miles downstream of treated sewage inflow. The dissolved oxygen concentrations of the water ranged from 6.4 to 7.8 milligrams per liter at site 1, and from 4.9 to 7.4 milligrams per liter at site 13. The average dissolved-solids concentrations were 60 and 97 milligrams per liter at sites 1 and 13, respectively. The average dissolved-solids load increased downstream about 35 tons per day. The average loads of 5-day biochemical oxygen demand, total phosphorus, and ammonia increased downstream about 2, 0.7, and 0.6 tons per day, respectively. The water in the study reach contained color, total iron, and manganese concentrations that exceeded limits recommended for public water supplies. Trace amounts of some pesticides and minor elements were present in both the water and bottom material at sites 1 and 13. The concentrations of most dissolved constituents were below recommended limits during the study and the Pearl River in the study reach may be considered usable for many purposes. (USGS)