Pentek Chromium-6 Filter

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Are you wondering if your household water in Memphis, Shelby County contains chromium-6, and what treatments might be needed? The EPA's monitoring data for the Memphis Light, Gas & Water system offers insight into regional chromium(VI) levels and helps guide treatment decisions.

Geogenic Hexavalent Chromium versus Industrial Sources

Chromium-6 Origins in Groundwater

Hexavalent chromium occurs naturally in some arid and alkaline aquifers due to geological conditions. It can also originate from industrial activities such as metal plating. In Shelby County, the supply is groundwater, which may reflect a mix of natural and human-influenced chromium(VI) presence.

Regional Industrial Impact on Chromium-6

Memphis is an urban area with industrial history, but EPA data does not show health-based violations for chromium-6 in the public water system. The detected levels indicate background or low concentrations typical of groundwater sources rather than concentrated industrial pollution.

Comparing Ion Exchange and Reverse Osmosis for Chromium(VI)

Ion Exchange Technology

Ion exchange processes specifically target certain charged ions like chromium(VI), exchanging them with less harmful ions. This technology can effectively reduce hexavalent chromium concentrations in household water.

Reverse Osmosis Filtration

Reverse osmosis uses a semipermeable membrane to remove a broad range of contaminants, including chromium-6, by filtering water under pressure. It provides comprehensive reduction but may waste more water and require space to operate.

Choosing Between Technologies

The decision depends on the household's water chemistry, usage, and preferences for maintenance and water conservation. Ion exchange may be more targeted, while reverse osmosis offers wider contaminant reduction.

Differences for Large Households, Second Homes, or Seasonal Properties

Household Water Volume Considerations

Larger households consume more water and may require treatment equipment with higher capacity or flow rates to maintain effective chromium(VI) reduction without pressure loss.

Second or Seasonal Residence Factors

For properties used intermittently, systems that can remain inactive without degrading performance or that are easy to re-initiate are beneficial. Treatment solutions need to accommodate variable water use.

Seasonal and Multi-Year Variation in Chromium-6 Levels

Monitoring Record Dates

The EPA monitoring in Memphis occurred mainly from February to December 2015 with 40 samples collected.

Range and Median of Chromium-6 Detection

Of these, 7 samples detected chromium-6 above the 0.03 microgram per liter reporting level, with the highest measurement at 0.1 micrograms per liter and a median of 0.06 micrograms per liter for detected samples. These figures represent concentration points in parts per billion.

Pathways for Chromium(VI) into Memphis Groundwater and Distribution

Natural Leaching and Aquifer Characteristics

Chromium-6 can enter groundwater through natural mineral dissolution in certain soil and rock formations.

Distribution System Considerations

While the water system uses groundwater, treatment and distribution processes may affect chromium-6 levels or forms, but EPA records for this system show no health-based violations.

Understanding Sampling Record Terms and Limits

Detected versus Non-Detected

Detection means that instruments measured chromium-6 at or above 0.03 micrograms per liter; nondetected means the concentration was below this reporting level, not zero.

Median and Range Explanations

The median is the midpoint value of detected concentrations—half were above, half below. The range indicates minimum and maximum values observed in the samples.

Legal and Health Standards

There is no federal maximum contaminant level (MCL) for chromium-6, but total chromium has an MCL of 100 micrograms per liter. None of the Memphis system's samples approach this level.

Next Steps: Testing Your Household Water

Because the EPA data reflects system-wide sampling, the exact chromium-6 concentration in your home's water is unknown. To determine your specific situation, order a laboratory test for hexavalent chromium concentration.

If results approach or exceed levels you consider concerning, the Pentek Chromium-6 Filter ships ready to configure and is designed to reduce chromium(VI) from household water effectively.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-12-08. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Memphis Light, Gas & Water (TN0000450), TN: 80 results across 2 listed contaminants, 7 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L