Comparison of trace metals in the intake and discharge water of power plants using "clean" techniques

Once-through, noncontact condenser cooling water at power plants is frequently discharged back to the fresh or saline water body used for its intake water. This study evaluated the potential effect that trace metals, collected using "clean" sampling and analytical techniques and discharged from a once-through, noncontact cooling water system from a power plant, have on receiving water bodies. A paired t-test was used to compare the intake and discharge concentrations of the metals. The metals analyzed were antimony, arsenic, barium, beryllium, boron, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc. "Clean" is a term applied to field and analytical procedures that are designed to reduce or eliminate ubiquitous metal contamination from samples collected for environmental monitoring. Study results indicate that there is no measurable difference between intake and discharge samples from a noncontact cooling water system, and, therefore, there is no net contribution of metals to receiving water bodies from this system.