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Effluent BODS: The effluent BODS concentrations ranged from <5 to 6 mg/L over the course of the evaluation, with an average concentration of 5 mg/L, and a median concentration of <5 mg/L. Standard 40 requires that over the course of the evaluation, the effluent BODS not exceed 45 mg/L on a 7-day average and 30 mg/L on a 30-day average, and represent a reduction of not less than 85 percent of the 30-day average influent. The averages refer to seven and thirty consecutive sample averages, and not consecutive days. A plot of the 7 and 30-day average concentrations and 30-day average percent removals, is shown in Figure 2. The 7-day average for effluent BODS ranged from <5 to 5 mg/L, the 30-day averages ranged from <5 to 5 mg/L and the percent removal remained consistent at 97 percent. As shown in Figure 2,the Clearwater Model CWW-450 plant met the requirements of Standard 40 for effluent BODS. 3.3 Suspended solids Suspended solids (SS) and volatile suspended solids (VSS) analyses were completed using Methods 209C and 209D of Standard Methods. The results of the SS analyses over the entire evaluation are shown in Figure 3. The data from both analyses are summarized in Table I. Influent suspended solids: The influent SS ranged from 100 to 370 mg/L during the evaluation, with an average concentration of 182 mg/L. The median influent suspended solid concentration during the evaluation was 180 mg/L. The influent VSS ranged from 75 to 280 mg/L during the evaluation, with an average concentration of 153 mg/L and a median concentration of 150 mg/L. Aeration chamber suspended solids: The aeration chamber suspended solids ranged from <5 to 21 mg/L during the evaluation, with an average concentration of 7 mg/L. The aeration chamber VSS ranged from <5 to 15 mg/L, with an average concentration of 6 mg/L. The median values for the aeration chamber were 5 mg/L suspended solids and <5 mg/L volatile suspended solids. Effluent suspended solids: The effluent suspended solids concentrations ranged from <5 to 10 mg/L during the evaluation, with an average concentration of 5 mg/L, and a median concentration of <5 mg/L. Over the course of the evaluation, NSF Standard 40 requires that the effluent suspended solids not exceed 45 mg/L on a 7-day average, 30 mg/L on a 30-day average and that the plant achieve �.- not less than 85 percent reduction of the 30-day average influent suspended solids concentration. A plot of the 7- and 30-day averages, as well as the percent removal, is shown in Figure 4. 6 Draft Report