Signal Decomposition of Conductivity Sensor Measurements on the Allegheny River, Pennsylvania.

Surface water conductivity measurements were used to evaluate the combined contribution of anions in western Pennsylvania from brines discharged by sources such as oil and gas wastewater treatment, coal-fired power plants, and coal mining activities. Conductivity sensor data were collected in the Allegheny River during a US Environmental Protection Agency and US Fish and Wildlife study that included seven sites covering 256 river km during the fall of 2012. Intermittent discharges, such as oil and gas wastewater, and continuous sources contributing to the conductivity were quantified using constrained and adaptive decomposition of time-series (CADETS) frequency analysis. CADETS was able to quantify the intermittent or short-term component of conductivity at sites where the intermittent fraction was 1 to 22% of the total conductivity. The demonstrated efficacy of the CADETS method for surface water quality analysis suggests it could be widely used to evaluate other water sensor data in rivers with both continuous and intermittent source impacts.