ETV Testing: CampWaterT Porta-5 Unit

During the winter of 2003-2004, the National Sanitation Foundation conducted an Environmental Technical Verification (ETV) testing program on the CampWater™ Porta-5 Water Purification Unit. The system uses ozonation and filtration to remove arsenic via co-precipitation. The design does not require any other flocculation, solids separation or clarification.

The testing program was funded by an Environmental Protection Agency (EPA) grant, and performed through a cooperative effort of  Delta Industrial Services, the University of Alaska at Anchorage (UAA) and Southwood Estates, a residential community in Anchorage, Alaska.

University personnel conducted the program at Southwood Estates where the feed water contained 27 μg/L arsenic and 0.62 mg/L iron. The test comprised three phases:

• Phase A was a continuous test to verify mechanical performance. The system was operated for 327 hours over a 17-day period, with starts and stops for adjustments during the first 48 hours and filter changes. The system was operated at 550 mV ORP; the source water was approximately 7.9pH. Arsenic removal during Phase A was approximately 33%.

• Phase B consisted of five tests conducted at varying pH and ORP levels to pinpoint the most effective combination for arsenic removal. A dosing pump was added to the system and muriatic acid (HCl) was used to adjust the pH of the feed water, with testing levels ranging from 7.0 to 7.9 pH. The system was operated at both 550 mV and 650 mV ORP. Arsenic, iron and manganese concentrations were analyzed on a total of 31 raw and treated water sample pairs. The most effective combination proved to be 7.5 pH and 550mV ORP, affording arsenic removal to 77%.

• Phase C was conducted as another continuous run, to verify improved arsenic removal efficacy with a feed water pH of 7.5 and ORP levels set at 550 mV. Treated water results from this test satisfied the Maximum Contaminant Level of 10 μg/L arsenic.

The National Sanitation Foundation approved the CampWater™ Porta-5 Water Purification Unit, and published the results in a complete report for the Environmental Protection Agency. EPA’s website contains the report in summary or full version format, as well as more information on the Environmental Technical Verification (ETV) process.