REMOVAL OF ARSENIC IN WATER WELLS
Hopkinton, MA homeowners may be quite surprised when they get their water test results back and see they have arsenic in their private well. It is estimated that approximately twenty percent (20%) of private wells in Massachusetts have levels of Arsenic that should be dealt with. Arsenic in water occurs naturally and is a colorless, tasteless, and odorless contaminant. However, other activities that could have left residuals include apple orchard spraying, coal ash disposal, and use of some pressure treated wood. While there are associated serious health threats with ingestion, there are effective removal methods for arsenic in well water. For a fact sheet on potential health affects, see the link at: who.int/mediacentre/.
AS V and AS III are the two primary forms of arsenic in water. Many removal media have a low capacity for removing AS III from the water, therefore, converting it to AS V for removal is a common approach. Determining the ratio of AS V versus AS III in the water is, therefore, critical. This will allow the design and implementation of a water filtration system that will effectively remove it from the water. There are methods to oxidize the AS III and convert it to AS V for ease of removal.
WATER TESTING, ANALYSIS & OTHER FACTORS
Having a complete laboratory water test and analysis, including parameters that can negatively impact removal media, is critical to a well designed, safe water treatment system that will remove arsenic in well water. pH can significantly affect media performance along with other competing ions such as Iron, Manganese, Hardness, Vanadium, Sulfate, Phosphate, Silica, Total Dissolved Solids, Suspended Solids and Hydrogen Sulfide. 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/.
MONITORING WATER USAGE
Determining water usage 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 – IMPORTANT!
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 – SAFE & EFFECTIVE ARSENIC FILTRATION
As arsenic in well water 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 the next scheduled service with your water treatment company. Service should be scheduled at intervals determined by the water use tracking data accumulated. This combined with appropriate water testing intervals are added safeguards to prevent arsenic from getting into the treated water entering the home.
If water tests reveal radon in water, an aeration system that removes the radon gas and safely vents it to outside ambient air is very effective effective. For more information about radon in water and how to remove it, see the link at https://h2ocare.com/radon-removal/.