1. How Perchlorate Can Enter Groundwater in the Westerly Area
Perchlorate is a chemical that can reach groundwater through sources such as industrial runoff, use of fertilizers, and atmospheric deposition. In Washington County, Rhode Island, the public water supply draws primarily from groundwater, which means any perchlorate present originates from environmental sources within the region. This chemical is not naturally occurring but can persist in water sources if introduced. Knowing how perchlorate enters the water helps households understand the potential for its presence and the importance of monitoring.
2. The Number of Samples and Wells Behind Westerly’s Water Quality Data
The Westerly Water Department, serving over 35,000 residents, participated in a federal occurrence survey from 2001 to 2005. During this time, 20 samples were collected and tested specifically for perchlorate. None of these tests detected perchlorate above the reporting level of 4.0 micrograms per liter. While this is good information, it is important to recognize that data from 20 samples over several years covers the water system at large, not each individual home. A small number of samples provides an overview but does not guarantee the condition of a specific household water source.
3. What You Should Note Before Seeking Treatment Advice
Before exploring solutions for perchlorate, households should obtain a water test of their own well or home supply tested by a certified laboratory. Knowing the exact perchlorate level in your specific water is essential because public system data represents the larger source area, not individual plumbing. Take note of your water source type, recent changes, and any issues with previous treatment equipment failure. This information helps tailor treatment recommendations to your situation.
4. Comparing Westerly’s Perchlorate Data to Neighboring Washington County Areas
While reviewing data from other systems or neighboring counties might seem helpful, it’s important not to overinterpret minor differences. Westerly’s public system shows no perchlorate detections above laboratory reporting limits during federal monitoring, and nearby areas may show similar or different results based on local conditions and sampling. Variations in source water and sample size mean comparisons should be made cautiously and only as a general reference.
5. The Role of Sample Depth, Well Depth, and Source Type in What to Expect
Perchlorate concentrations can vary depending on how deep groundwater is drawn and the type of source. Deeper wells might have different exposure levels than shallow ones. Since Westerly’s water system uses groundwater wells that serve multiple connections, the perchlorate measurements reflect a combination of depths and locations. Individual household wells may differ, especially if they tap into unique strata or have localized influences. These factors impact the likelihood and concentration of perchlorate you might observe.
What You Should NOT Conclude from Area Data
It is crucial to understand that the lack of perchlorate detection above reporting levels in Westerly’s public water system does not guarantee your home is free from it, nor does it indicate any health risk by itself. The data does not show violations or unsafe conditions but only reflects measurements at the system level. Your own water testing is the only way to know your household’s water quality precisely. In case of treatment failure, consider the C-Series Perchlorate Filter, a system designed to address perchlorate presence by configuring easily for your home water treatment needs.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2003-07-31. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR1 monitoring (2001-2005) for WESTERLY WATER DEPARTMENT (RI1559512), RI: 20 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level