Water Quality - Related to Surface Water and Purified Recycled Water

The following Water Quality Reports are for informational purposes.  We often get inquires related to the water quality of surface water from the City of Santa Cruz, our groundwater, and purified recycled water.  The City's surface water supplies and purified recycled water are two options that the District is considering to diversify our long-term water supply portfolio.

Water Quality Reports related to Surface Water Transfer Option

City of Santa Cruz -Water Quality Reports

City of Santa Cruz and Soquel Creek Water District's Pilot Surface Water Transfer Study

County of Santa Cruz- Website

Water Quality Reports related to Advanced Water (Purified Recycled Water) Option

  • Technical Memo on Constituents of Emerging Concern (CEC) Removal through Advanced Treatment and Comparison with Surface Water and Groundwater for Soquel Creek Water District (October 2017)
  • National Water Research Institute Independent Advisory Panel for Soquel Creek Water District- Report #1 and Report #2
  • Technical Memo on Nanoparticle Concerns (February 2016) - This memorandum was drafted in response to a specific request from the Soquel Creek Water District (SqCWD) regarding nanoparticles. The SqCWD wanted to know the latest information on nanoparticles as they pertain to potable water reuse projects. Nanoparticles are not regulated for potable water reuse projects (or potable water projects, for that matter). In conversations with the State of California Division of Drinking Water (DDW) in January 2016, the DDW defined their position on nanoparticles, which is that existing regulations are protective of public health and that there is no intent to regulate nanoparticles.
  • From Other Projects/Agencies that are developing or have implemented purified recyled water projects
    • Effectiveness of Advanced Water Treatment for Pure Water Monterey Project- CECs (May 2018)
    • Frequently Asked Questions from the Orange County Groundwater Replenishment System (GWRS) Project Website
      •  Question: Does the Orange County Groundwater Replenishment System Advanced Wastewater Purification Process remove pharmaceuticals and hormones?  Answer: Yes.  OCWD tests for more than 400 compounds. All test results are well below permit levels or at non-detection (ND) levels. For example: 28 Volatile Organic Compounds – All ND; 39 Non-Volatile Synthetic Organic Compounds – All ND; 8 Disinfection By-Products – All ND; 10 Unregulated Chemicals – All but one ND, all are below permit levels; 51 Priority Pollutants – All ND; 16 Endocrine Disrupting Chemicals and Pharmaceuticals – All ND.
      • Question:  Is water produced by GWRS safe?  Answer:  Absolutely.  The GWRS water undergoes constant, rigorous testing before being released back into the environment.  It exceeds all state and federal drinking water standards. The project was reviewed, approved and permitted by the California Department of Public Health and California Regional Water Quality Control Board, Santa Ana River Basin, to ensure public health, water quality and environmental compliance before allowing injection along the coast (approval received on January 10, 2008) and percolation into deep aquifers (approval received on January 18, 2008). The permits require continuous water quality testing and sampling.  If the water does not meet water quality requirements, the plant would be shut down immediately.  The permit establishes criteria for the GWRS treatment, Total Organic Compounds (TOC) limits, and travel time and blending requirements. One of the provisions of the permit requires that an Independent Advisory Panel (the Panel) provide an on-going periodic scientific peer review of the GWRS. The permit specifies minimum qualifications for the Panel members and requires that the Panel meet at least annually during the first five years, and then every two years thereafter. The Panel is appointed and administered by the National Water Research Institute (NWRI), and made up of experts in toxicology, chemistry, microbiology, hydrogeology, environmental engineering, public health and water treatment technology.
    • 2018 Orange County Water District's Groundwater Replenishment System's Annual ReportCWD GWRS Annual Report 
    • Pure Water Monterey's Engineering Report (April 2019)
    • Micropollutant Removal from Water by Membrane and Advanced Oxidation Processes- A Review (Journal of Water Resources and Protection (April 2017)
    • Pure Water San Diego's Title 22 - Questions and Responses (October 2018)


Water Quality Related Septic Systems and Groundwater Basins