The City has a conjunctive-use water system that uses both surface and groundwater. After treatment at the Regional Water Treatment Facility in Woodland, the surface water is pumped into a transmission line (larger diameter pipe moves water from sources to storage and/or distribution) and travels six miles to Davis. Surface water enters into the City’s distribution system at three main locations in west, central and south Davis.

The City’s wells pump groundwater directly from underlying aquifers. Four deep-aquifer wells pump groundwater into the transmission line, which is then blended with the surface water prior to entering the distribution system and arriving at the tap. The other wells pump directly into the distribution system, only on an as-needed basis to relieve the four deep wells. The ratio of surface water to groundwater varies throughout the year. In colder months, when water demand is low, the City uses primarily surface water. In warmer months when there is higher water demand, more groundwater is pumped to meet demand. Wells are still operated periodically during the low-demand months to ensure that they are exercised properly and as required for water quality testing.

For an overview of the City's water utility, please view the Water Utility 101 PDF.  

Learn more about the City's surface and groundwater supplies: Water Sources and Production

The City's water infrastructure includes 191 miles of distribution and transmission mains, three water storage tanks and nine groundwater wells. The Water Division has three water crews that oversee production, distribution and programs. The production crew operates the water system and maintains pressure, coordinates deliveries of surface water from the Regional Water Treatment Plant in Woodland and operates the three water storage tanks and nine groundwater wells. The distribution crew maintains the 191 miles of distribution and transmission mains, repairs main breaks and replaces hydrants, valves and service lines. The programs crew monitors Aclara (the City's meter database), performs water meter reads, testing and water meter and reader maintenance and performs backflow testing. 

Fire Hydrant Clearance Standards

Access to fire hydrants is critical to successful firefighting operations. The standard three-foot clearance required around fire hydrants, required by the California Fire Code, is a good start. However, vegetation can obscure the area between a hydrant and the street until the firefighting crew is almost past the hydrant. For this reason, a "window" of visibility was added to the Davis Municipal Code to ensure that hydrants can be seen from a distance.

A clear space of 36 inches (914 mm) shall be maintained around each hydrant. The space shall be measured from the center of the hydrant in a circle with a radius of 36 inches. In addition, a clear space defined by a sector of 90-degree arc shall be maintained to the street or location where a fire engine will connect to the hydrant. Vegetation or obstructions less than 6 inches (150 mm) above grade shall be disregarded. Illustration is provided below:

Section 507.5.5, California Fire Code, 2019 Edition
Section 13.01.040 (c), Davis Municipal Code

Asbestos-Cement (AC) Pipe Work

In order to ensure the safety of our staff and the public, the City has updated its policies and procedures to reflect updated best practices when working with asbestos-cement (AC) pipe. As a result, whenever pipes containing asbestos will be cut, repaired, removed or modified in any way, certain safety procedures for City staff and the public will be put into place, which may include:

• Staff wearing safety respirators and hazardous materials management gear (white suits)
• Establishment of a safety barrier to keep the public at least 20 feet away from the work area
• Signage posted about asbestos and the health dangers of contact with asbestos that are visible up to 20 feet away

You may notice or see these safety procedures as work gets done on these pipes. The City recognizes that visually seeing this type of work or gear may cause some concern, but please rest assured that this is only being done out of an abundance of caution and in keeping with best practices in asbestos management. Please see below for additional information on asbestos-cement pipe, water quality and some frequently asked questions.

About Asbestos-Cement Pipe

Asbestos-Cement Pipe, also known as AC pipe or transite pipe, is a pipe made of cement and asbestos fibers. AC pipe was first used in North America in the 1930s for potable water distribution and is a mix of cement slurry and less than 20% asbestos fibers. AC pipe was a common choice for underground water mains during the 1940's, 50's, and 60's because it had better flow for water through the pipe, a long lifespan, corrosion-resistant attributes and ease of installation when compared to other pipe materials. As the infrastructure of municipalities’ age, pipes are replaced at the end of their useful life, including those made of asbestos-cement.

The Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) for asbestos in drinking water of 7 MFL (million fibers per liter > 10 µm in length). Asbestos in drinking water comes from two main sources:

1. Decay of water mains constructed of asbestos-containing cement 
2. Erosion of naturally occurring asbestos deposits into watersheds

The City of Davis samples the water distribution system annually for asbestos and consistently does not detect asbestos in the water. However, since Davis does have AC pipe in the water system, the City will continue to sample annually for asbestos to ensure the highest quality of water to customers. Due to the non-detection of asbestos, the annual water quality report doesn’t reflect the sampling because only detectable constituents are allowed in the report.

• Why are there asbestos pipes? Asbestos was a standard component in cement pipes prior to the 1980s due to its high strength, low-cost and corrosion-resistance.
• Is there asbestos in my water? There is no detectable amount of asbestos in Davis’ drinking water.
• Can I drink the tap water if the pipes have asbestos? Yes, the City samples annually to verify no leaching of asbestos from the water pipes and repair and replacement of the aging water infrastructure is ongoing in the City.
• Are you planning to remove all the asbestos pipes in the City? Not all at once. Pipes containing asbestos will be removed on an as-needed based upon its age and condition.
• Why is there a change in how asbestos pipe removal/repair is being treated/noticed? Recent reviews of City policies were performed and the City’s standard practice is being updated with new best practices in safety regarding asbestos abatement.
• Why doesn’t the City notify residents in advance of asbestos pipe repair? Unfortunately, the City does not always know in advance when asbestos pipe may need repair/replacement and if pipes involved in planned or emergency work contain asbestos. Once it is determined that a pipe containing asbestos will need to be removed or replaced, proper safety procedures will be put into place prior to work commencing.

• US EPA asbestos page - https://www.epa.gov/asbestos/learn-about-asbestos
• Yolo Solano Air Quality Management District information about asbestos in pipes in your home - https://www.ysaqmd.org/rules-compliance/asbestos/homes/