How to Read the Tables

The tables on the following pages list parameters which DDW requires the City to monitor, which may be associated with primary [health],secondary [aesthetic], or no established standards. These tables summarize monitoring from January - December 2014, with minor exceptions where some 2013 data is included (see LRAA definition below). The tables list all parameters that were detected at or above DDW's Detection Limit for Purposes of Reporting (DLR).

Definition of Terms

  • Action Level (AL): The concentration of a contaminant that, if exceeded, triggers treatment or other requirements that a water system must follow.
  • Location-based Running Annual Average (LRAA): The average of the most recent four quarters of monitoring performed at a distinct location in the distribution system. LRAAs are calculated quarterly using twelve months of data and may include values obtained in 2013.
  • Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs or MCLGs as is economically or technologically feasible. Secondary MCLs are set to protect the odor, taste and appearance of drinking water.
  • Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water, below which there is no known or expected health risk. MCLGs are set by the U.S. EPA.
  • Maximum Residual Disinfectant Level (MRDL): The level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap.
  • Maximum Residual Disinfectant Level Goal (MRDLG): The level of a disinfectant added for water treatment below, which there is no known or expected health risk. MRDLGs are set by the U.S. EPA.
  • Notification Level (NL): Health-based advisory levels established by DDW for chemicals in drinking water that lack maximum contaminant levels (MCLs). When chemicals are found at concentrations greater than their notification levels, certain requirements and recommendations apply.
  • Public Health Goal (PHG): The level of a contaminant in drinking water below, which there is no known or expected health risk. PHGs are set by the California EPA.
  • Primary Drinking Water Standard (PDWS): MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements.

Abbreviations

  • A: absent
  • CA SMCL: California secondary maximum contaminant level
  • CSD MDL (City of San Diego Water Quality Lab method detection limit): lowest quantifiable concentration of a measured analyte detectable by the lab
  • CU: color units
  • DDW: State Water Resources Control Board Division of Drinking Water Programs
  • DLR: detection limit for reporting
  • gr/Gal: grains per gallon
  • ml: milliliter
  • MWD: Metropolitan Water District of Southern California
  • n/a: not applicable
  • ND: not detected (less than DLR, where applicable)
  • NTU: nephelonmetric turbidity units
  • OU: odor units
  • pCi/L: picocuries per liter (a measure of radiation)
  • ppb: parts per billion or micrograms per liter (ug/L) - [1 ppb = 0.001 ppm]
  • ppm: parts per million or milligrams per liter (mg/L) - [1 ppm = 1,000 ppb]
  • TT (treatment technique): a required process intended to reduce the level of a contaminant in drinking water
  • uS/CM: micro-siemens/centimeter
  • > greater than