UCMR 5 Unregulated Contaminants


Unregulated substances are those for which EPA has not established drinking water standards. Avondale monitors for those substances to assist the EPA in determining the occurrence of unregulated contaminants in drinking water and whether future regulation is warranted. The EPA issues a new list of up to 30 unregulated contaminants for monitoring every 5 years.


The EPA has established UCMR 5 Minimum Reporting Levels (MRLs) based on the capability of the analytical method, not based on a level established as “significant” or “harmful.” UCMR 5 results reported at or above those MRLs should be interpreted accordingly. The detection of a UCMR 5 contaminant does not represent cause for concern, in and of itself. 29 of the 30 analytes are per and polyfluoroalkyl substances (PFAS) compounds, with the 30th being lithium. In April 2024, Avondale began monitoring the first round of the Fifth Unregulated Contaminant Rule (UCMR 5) and plans to report the results in the 2024 Water Quality Report. The Avondale UCMR4 results are noted in the UCMR4 table later in this report. Any unregulated contaminants detected by the City of Phoenix’s UCMR5 results (completed in 2023) are reported in the UCMR5 table later in this report as well. If the EPA determines that regulation is warranted for any of the monitored substances, Avondale will take the necessary steps to comply with any new requirement.


Terms & Abbreviations To help you understand the terms and abbreviations used in this report, we have provided the following definitions:


6 Action Level (AL) - the concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow


6 Acre-foot (AF) - a unit of volume that would cover one acre to a depth of one foot, or 325,851 gallons 6 Locational Running Annual Average (LRAA) - an average of monitoring results for the previous 12 calendar months


6 Maximum Contaminant Level (MCL) - the “Maximum Allowed” is the highest level of a contaminant that is allowed in drinking water MCLs are set as close to the MCLGs as feasible using the best available treatment technology


6 Maximum Contaminant Level Goal (MCLG) - the “Goal” is the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety


6 Maximum Residual Disinfectant Level (MRDL) - the highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants


6 Maximum Residual Disinfectant Level Goal (MRDLG) - the level of a drinking water disinfectant, below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants


6 NA = not applicable; ND = not detected 6 Nephelometric Turbidity Unit (NTU) - measure of how light is scattered by particulate matter


6 Parts per million (ppm) or Milligrams per liter (mg/L) - one part per million corresponds to one minute in two years or a single penny in $10,000


6 Parts per billion (ppb) or Micrograms per liter (ug/L) - one part per billion corresponds to one minute in 2,000 years, or a single penny in $10,000,000


6 Parts per trillion (ppt) or nanograms per liter (ng/L) - one part per trillion corresponds to one minute in 2,000,000 years, or a single 6 penny in $10,000,000,000 6 Picocuries per liter (pCi/L) - picocuries per liter is a measure of the radioactivity in water 6 RAA - running annual average 6 Treatment Technique (TT) - required process to reduce a level of a contaminant in drinking water


PAGE 5 2023 AVONDALE WATER QUALITY REPORT


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