Meeting 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.
These 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 state-of-the-art treatment plants at two locations.
- Surface water imported through the Bay-Delta, which typically comprises roughly 80 percent of our drinking-water supply, can occasionally have an earthy-musty taste or smell, caused by algae blooms from warm temperatures and increased sunlight. These taste and odor episodes usually last a few days, from late spring through September, and do not impact the safety of our drinking water.
- Zone 7 currently provides powdered activated carbon seasonally at the Del Valle and Patterson Pass conventional treatment plants to assist in reducing levels of odor-causing compounds.
- 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.
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.