Water Quality

  • Providing customers with safe, reliable, and affordable drinking water, now and in the future.  

    Keep our groundwater safe

    Join the City in protecting groundwater, our secondary source of drinking water. Groundwater is runoff from rain or other precipitation that soaks into soil, filling cracks in beds or rock deep underground, called aquifers. If we’re not careful, small amounts of chemicals, - either spilled, leaked or dumped - can find their way into our aquifers.  

    How you can help

    • Water Quality Report
    • Drinking Water Sources
    • Bull Run Update
    Water Quality Report

    Water Quality Report 2017

    • Each year the City of Gresham provides the Drinking Water Quality Report to all of its customers.
    • The report contains important information about Gresham’s drinking water and water system.
    • The 2017 Drinking Water Quality Report contains results from the 2016 calendar year.
    • A paper copy or translation of the report can be requested by calling 503-618-2525.


    Drinking Water Sources

    Gresham’s drinking water comes from three sources:

    1. The Bull Run Watershed, located in a protected area of the Mt. Hood National Forest, managed by the Portland Water Bureau.

    2. The Columbia South Shore Well Field, also managed by the Portland Water Bureau, is used on occasion to supplement the Bull Run. Groundwater from these wells comes from three different aquifers:      
      • Blue Lake Aquifer
      • Troutdale Sandstone Aquifer
      • Sand and Gravel Aquifer
    3. The Cascade Well Field, managed by Rockwood PUD, taps into the Sand and Gravel Aquifer. This groundwater is used to supplement our supply from the Portland Water Bureau.  
      Bull Run Update

      Water quality update

      • Gresham’s primary source of water is the Bull Run watershed, a federally protected water source managed by the City of Portland.  The City has two additional water supplies, if needed.
      • Recent Bull Run water monitoring results detected small levels of Cryptosporidium.  At this time, there is no evidence of an increased health risk.
      • The City of Gresham will continue to monitor water quality reports in coordination with Portland and local health agencies. 

      Precautions customers can take 

      • People with severely weakened immune systems should seek specific advice from their health care providers about drinking water.
      • You can use a filter. Make sure that it is labeled and certified to remove Cryptosporidium and is NSF/ANSI 53 or 58 rated. Look for the language “cyst reduction” or “cyst removal”. Reverse osmosis and carbon filters are the most common types of filters available. Make sure that the manufacturer states “absolute” pore size of 1 micron or smaller.