Treatment and Water Supply Changes In Response to Water Quality Impacts from Zaca Fire

Goleta Water District’s top priority is ensuring a reliable supply of high quality water for the residents of the Goleta Valley. Comprehensive testing and treatment programs, a trained and state-certified water quality staff and round-the-clock vigilance by water professionals help assure the safety and quality of Goleta’s water.

Effects of the Zaca Fire

Recently the District has received questions about potential quality impacts from the Zaca fire. Runoff from this winter’s heavy rains increased the flow of nutrients and organic material into Lake Cachuma due to the ash and debris left by the Zaca fire.

These additional organic materials can also combine with the chlorine disinfectant used in water treatment to eliminate bacteria, and form substances called Trihalomethanes (THM) and Haloacetic acids (HAA) as byproducts. When ingested over long periods of time at levels above state and federal standards, these byproducts have been linked to adverse health effects.

District Water Meets Standards

District water is currently within the health standards for these byproducts. There is a possibility that in the coming months, test results for THM and HAA could rise because warmer water temperatures tend to increase production of byproducts. In response, the District is taking assertive treatment and water supply actions and expects to remain within quality standards.

Treatment Plant Changes to Improve Quality

Working with the treatment plant design engineers, District staff developed and is implementing treatment process adjustments that are expected to reduce the byproducts level by:

  • Reducing the amount of chlorine added at the plant.
  • Relocating the chlorine injection point to provide less contact time before it enters the flocculation area.
  • Increasing the alum and Powdered Activated Carbon feed rates to decrease byproduct forming constituents.
  • Conducting extensive testing to determine the optimum treatment for minimizing disinfection byproducts.

Water Supply Changes Also Improve Water Quality

District staff also developed ways to reduce disinfection byproducts by adjusting the water supply to use more groundwater. This supply is very low in organic carbon and therefore low in disinfection byproducts. Treatment plant personnel will pump groundwater into the distribution system. Water pipeline distribution system personnel will operate the booster pumps and reservoirs to distribute the well water throughout the system.

It should be noted that well water has more taste and odor due to its naturally high mineral content. The District’s water is, therefore, expected to undergo some noticeable taste changes in the coming months. District staff will do its best to minimize these harmless aesthetic changes.

Constant Water Quality Vigilance

The District will continue to closely monitor water from the treatment plant and pipeline distribution system to ensure that the system is effectively reducing disinfection byproducts, making adjustments as needed, to assure that your water meets standards. Staff will also monitor the water in Lake Cachuma as its quality returns to normal.

A detailed water quality report will be mailed to all customers in June with extensive information about District water quality.

For more information about water quality, contact Greg Paul at (805) 879-4671, watch the District’s website at www.goletawater.com, or go to the United States Environmental Protection Agency Safe Drinking Water website at www.epa.gov/safewater/index.html