Davis has adequate water resources

By Ali Ghorbanzadeh

My professional life has been devoted to improving the state’s water supply and water quality. I received a Ph.D. in groundwater hydraulics from UC Davis, and I have worked for the state Department of Water Resources for more than three decades in the area of water supply and water quality. There are important issues concerning the pending Measure I vote that require clarification.

Davis has always complied with the federal Environmental Protection Agency standards. The city has never violated water quality standards. Davis water has been safe for drinking and public use. Although it is high in calcium and magnesium, these minerals primarily cause a build-up of residues when the water is exposed to air, such as on shower heads, faucets and sometimes in water heaters. These minerals have no adverse health effects for humans.

In fact, I and my family of five have been drinking Davis water for decades. Whenever we have a choice between tap water and bottled water, we choose the tap. This is because we trust that the EPA standards governing tap water will produce safer water than water that is exposed to degenerating plastic while being kept in storage. Our family also has managed quite well without a water softener.

The proponents of the Woodland-Davis surface water project argue that it is necessary because, over time, the deep aquifer will be depleted or it will become degraded. No one knows when or if this will occur, and there are many indications that we will have time to explore a more cost-effective project and slowly build a fund from future development and our existing ratepayers to pay for the project.

The Brown and Caldwell Engineers Phase II Deep Aquifer Study of July 2005 that was commissioned by the city acknowledged that: “Because the average water levels in deep wells do not appear to be decreasing over time, recharge is in approximate equilibrium with extractions from the deep aquifer.

“The positive conclusions in this study have been the high apparent sustainable yield of the E-lower sand sequence and the existence of good producing deposits throughout the deep aquifer, even in East Davis. The fact that water levels in deep and intermediate wells rebound seasonally indicates that recharge is currently adequate to offset pumping.”

Rob Beggs of Brown Caldwell Engineers, who was invited by staff to address the Water Advisory Committee, said they studied a sample of the city’s deep wells. He said the wells seemed healthy and were replenishing, that he saw no sustainability problems “at current levels of usage” and that the deep aquifer appeared to be well-isolated from contamination.

The good news is that, because conservation continues to increase and the city is planning to re-pipe its municipal irrigation from the intermediate aquifer, we should be able to remain at or below current levels of use.

Graham Fogg, one of the leading proponents of the surface water projects, wrote in October 2011 that in Davis, “the groundwater levels appear to be recovering more or less fully every year following the dry season, indicating it is not yet in overdraft with respect to water quantity.” He further stated, “The changes in groundwater quality will not be sudden, but will likely continue on a decades to centuries time scale.”

No one knows how much water is available in the deep aquifer. However, we do know that the demand for water will increase with population growth and growth on the UC Davis campus. We need to plan over time for this need. There are two immediate steps that we can take:

* The city should further implement the water-saving practices that the public has adopted since water meters were first installed. The city needs to provide financial incentives for low-water-use landscaping, low-water-use home fixtures and low-water-use monthly bills. The city needs to prepare peak control programs, such as alternate watering days. The city, just like the public, needs to monitor and report its bi-monthly water use for its total operations.

* The city should implement a water reuse plan for irrigation purposes. The city should further use intermediate wells for park, school district and greenbelt irrigation. These measures will drastically reduce the amount of fully treated water used within the city and the amount of effluent to be treated.

I support enhancing our water quality and water supply with surface water. With the growth of the city, these measures eventually will be necessary. However, we need to collect the money over a period of time. New developments need to pay toward a water treatment project. Some rates should be collected over a period of time from existing ratepayers to pay for the water treatment plant in the future. The huge proposed rate increases at this time could place many of the Davis ratepayers in grave financial stress.

— Ali Ghorbanzadeh is an engineer who lives in El Macero.