|Use an infiltrometer or permeameter to measure field saturated hydraulic conductivity (K<sub>S</sub>) in at least 5 locations or at a rate of one measurement for every 25 m<sup>2</sup> of filter bed surface area, including inlet and lowest elevation areas. Compare mean and individual values to the design specification or trigger value (See Triggers for follow-up and corrective actions below) to determine if follow-up tasks are needed.
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|Use an infiltrometer or permeameter to measure field saturated hydraulic conductivity (K<sub>S</sub>) in at least 3 locations for areas up to 2,500 m<sup>2</sup> and one additional location for each additional 1,000 m<sup>2</sup> of filter bed surface area, including inlet and lowest elevation areas. Compare mean and individual values to the design specification or trigger value (See Triggers for follow-up and corrective actions below) to determine if follow-up tasks are needed.