Activities that could have left arsenic residuals include apple orchard spraying, coal ash disposal, and use of some pressure treated wood, however, it also occurs naturally and is a tasteless, odorless and colorless contaminant. While there are serious health threats associated with ingestion, there are effective methods for removing arsenic from well water. For details on potential health affects, see the link at: http://www.who.int/media.
FORMS OF ARSENIC IN WATER
The primary forms of Arsenic in well water are AS III and AS V. As many arsenic removal media have a low capacity for removing AS III from the water, converting it to ArS V (which is easier to remove) is a common approach. As such, determining the ratio of the two in the water is critical in allowing the design and implementation of a water treatment system that will effectively and safely remove it from the water. There are methods to oxidize the Arsenic III and convert it for ease of removal from the water supply. For a full article on this topic which we’ve had published in Water Technology Magazine, go to our publications section and click on the Arsenic removal article at https://h2ocare.com/publications/
WATER TESTING & ANALYSIS
Having a complete laboratory water test and analysis, including parameters that can negatively impact arsenic removal media, is critical to a well designed, safe water treatment system that will work properly. pH can significantly affect the media performance along with other competing ions such as Iron, Manganese, Hardness, Vanadium, Sulfate, Phosphate, Silica, Total Dissolved Solids, Suspended Solids and Hydrogen Sulfide.
WATER USAGE MONITORING
Water usage determination is also critical to designing an effective removal system that will have the proper capacity. Key information would include well pump size, well pump flow rate, size of the incoming water line, number of residents in the home, the number of bathrooms, space availability for equipment installation, electrical availability and water discharge location or restrictions, among others.
TRACKING WATER USAGE POST SYSTEM INSTALLATION
A couple of key components for consideration when designing this type of system include:
- Utilizing a meter to track flow rate and total gallons processed is critical to determine the home’s water demand.
- Gallons used readings also assist in uncovering any potential leaks in the home such as running toilets, which will unnecessarily prematurely deplete the arsenic media’s capacity.
LEAD/LAG TANKS WILL ADD A SAFETY FEATURE
Because Arsenic is a tasteless, colorless and odorless contaminant, it is particularly important to have two tanks in series in case the first tank is depleted prior to scheduled service with your water treatment company.
Service should be scheduled at intervals determined by the water use tracking data accumulated. This approach, combined with appropriate water testing intervals are added safeguards to prevent this contaminant from getting into the treated water entering the home.