Interpreting Measured Ranges Versus Federal Standards
EPA Health-Based Violations and Their Meaning
The Providence public water system (PWSID RI1592024) has three health-based violations noted in federal records. These are specific incidents and not continuous conditions for all water customers. Such data reflect compliance findings and do not always indicate current or uniform water quality at every connection.
Lead Level Reporting and Its Role
Lead sampling reports show a 90th percentile level of 0.01 mg/L as of June 2026, which originates from distributed water in the system rather than source water. This percentile represents a statistical measure, not a guaranteed level at any household tap.
Example: Clarifying Median and Range for Homeowners
Median Values Explain Typical Conditions
When the record lists median values, these indicate central tendency in sampled points and times, helping homeowners gauge usual water quality. For instance, a median lead level being low suggests most samples fall below that threshold.
Range Shows Variability, Not Individual Risk
The range in sampling data indicates the spread between lowest and highest detected values, highlighting variability but not necessarily a health danger at the extremes.
Origins of Constituents in the Providence Water System
Surface Water as the Primary Supply
The Providence system draws entirely from surface water sources. Constituents detected arise from natural and environmental factors affecting these surface waters, before treatment and distribution.
Distribution System Influences
Water quality can change once it enters the distribution network due to pipe materials and residence time. Lead detected is often related to plumbing rather than the original supply.
Understanding Sampling Terminology
The Meaning of ‘Detected’ in Records
Detected means an analytical instrument has measured a specific constituent in a water sample. It does not imply the presence exceeds any health or aesthetic standard.
Significance of Median and Range
Median is the middle value in a data set, useful for understanding typical exposure levels, while range highlights the extent of variation among samples collected.
How Source and Sampling Depth Affect Results
Impact of Surface Water Intake Versus Wells
Surface water sources, like those in Providence, show different constituent patterns than groundwater wells, which may have different contaminant profiles.
Sampling Depth and Location Variations
Samples taken closer to the water source usually reflect raw water quality. Samples taken from taps in homes represent water after distribution and possible plumbing influence.
Closing Summary and Data Source
This information references the Providence-City of public water system record (EPA PWSID RI1592024). It covers system-wide measurements and is not a substitute for individual household water testing. See the EPA Safe Drinking Water Information System for official data.
Considering these points can help you compare technical options for securing safe drinking water at home, such as employing a C-Series Safe Drinking Water Filter, which ships ready to configure and addresses various concerns documented in local water records.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2026-06-30. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA SDWIS record for PROVIDENCE-CITY OF (RI1592024), surface water supply, serving 333142 people: 3 health-based violations of 10 total; lead 90th percentile 0.01 mg/L