Your WaterFlood and Stream ManagementWatershed and Environment

wq-labMeeting and Beating the Standards

All of Zone 7's water delivered to its retailers serving homes and businesses in Livermore, Pleasanton, Dublin and Dougherty Valley meets state and federal health-related drinking water standards and, in almost all cases, the quality is much better than required. In addition, Zone 7 water meets most of the Agency's own, more stringent, water-quality targets.

ultrafiltrationplant_tour.jpgThese internal targets were developed for an additional margin of safety and to address local concerns regarding such things as taste, odor and water hardess. Zone 7's Water Quality Management Program -- developed jointly by Zone 7 and its stakeholders, including its water retailers -- establishes internal targets and policies for both treated and untreated water quality. These targets help guide operations and help provide a basis for upgrading or improving facilities and providing new facilities when necessary. In addition to ongoing internal agency planning, Zone 7 works closely with various organizations to protect the quality of source water locally and at the state level.

For various reports and planning documents addressing water quality, click here.

About Our Treatment Facilities

We operate three treatment plants at two locations.

Addressing Challenges

  • Surface water imported through the Sacramento-San Joaquin River Delta and conveyed via the South Bay Aqueduct, along with local runoff from Del Valle Reservoir, are the major sources of raw water supply for our surface water treatment plants. In recent years, treating this water supply with currently installed treatment processes at our treatment plants has become increasingly difficult due to more frequent algae blooms that can cause taste and odor problems, blue-green algae blooms that can produce algal toxins, high levels of organic matter, diurnal fluctuations in temperature and pH, and high alkalinity. Addition of the ozonation process at Zone 7’s treatment plants will enhance treated water quality and has been included in Zone 7’s Capital Improvement Planning and Asset Management Planning since 2006. Zone 7 is currently in the process of implementing ozonation at its treatment plants. Click here for more information about the Del Valle Water Treatment Plant (DVWTP) Ozonation Project.
  • Groundwater typically has more minerals and is "harder" than surface water, but it is just as safe. Water becomes hard by picking up soluble minerals as it seeps through soil and rock into groundwater storage.
    • The Mocho Groundwater Demineralization Plant was opened in 2009 to slow down the buildup of salts and minerals in the groundwater basin per the Salt Management Plan portion of the Groundwater Management Plan, while improving delivered water quality.
    • For a fact sheet about hard water, click here.

Improvements on Tap

For information on planned water-quality projects over the next 10 years starting in the 2015-16 fiscal year, go to Zone 7's latest Capital Improvement Program document by clicking here.

Bottled vs. Tap?

Learn about the environmental, economic and other benefits of drinking tap water over bottled by clicking here.