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EXECUTIVE SUMMARY <br /> Testing of the Clearwater Ecological Systems, Inc. Model CWW-450 Home Aeration Treatment <br /> System was conducted under the provisions of NSF Standard 40 for Individual Aerobic <br /> Wastewater Treatment Plants (July 1990 revision). NSF Standard 40 was developed by the NSF <br /> Joint Committee on Wastewater Technology. <br /> The performance evaluation was conducted at the NSF Wastewater Technology Test Facility in <br /> Chelsea, Michigan, using wastewater diverted from the Chelsea municipal wastewater collection <br /> system. The evaluation consisted of six months of testing, during which a seven week stress test <br /> was conducted. The evaluation consisted of three weeks of dosing without sampling to allow for <br /> plant start-up, sixteen weeks of dosing at design flow, seven weeks of stress test and five weeks <br /> of dosing at design flow. Sampling started in the fall and continued through the winter and into <br /> spring, covering a full range of operating. temperatures. <br /> Standard 40, in Section H. (3) of Appendix A, provides for exclusion of up to ten percent of the <br /> effluent sample days, not to exceed one during stress testing, in completing the pass/fail <br /> etermining if the plant met the pass/fail criteria. <br /> determination. No samples were discarded in d <br /> The average effluent BODS was 5 mg/L, ranging between <5 and 6 mg/L, and the average <br /> effluent suspended solids was 5 mg/L, ranging between <5 and 10 mg/L. Over the course of the <br /> evaluation, the effluent pH ranged from 7.5 to 8.1. <br /> The Clearwater CWW-450 produced an effluent that successfully met the performance <br /> requirements established by NSF Standard 40 for Class I effluent. <br /> The maximum arithmetic mean of seven consecutive sample days was 5 mg/L for BODS <br /> and 8 mg/L for suspended solids,both well below the allowed maximum of 45 mg/L. The <br /> maximum arithmetic mean of 30 consecutive sample days was 5 mg/L for BODS and 6 <br /> mg/L for suspended solids, both well below the allowed maximum of 30 mg/L. Removal <br /> rates for BODS were consistent at 97 percent, while the suspended solids ranged from 96 <br /> to 97 percent, both well above the requirement of 85 percent. <br /> The effluent pH during the entireCWW 450 also ation metbetween <br /> the requirements forwithin <br /> noise leverequired <br /> ls (less than <br /> of 6.0 to 9.0. The Clearwater <br /> 60 dbA at a distance of 20 feet) and color, threshold odor, oily film and foam. <br /> r <br /> ii Draft Report <br />