The state water board approved a major policy change this month agreeing to allow heavily treated effluent to be mixed directly with potable water supplies.
There’s certainly the ick factor in this discussion, but in an arid state with droughts always possible, utilizing water resources wisely is paramount. And, it’s not a new concept.
Two realities:
Think of all of the cities north of Tracy/Manteca that discharge treated sewage into the Delta — Stockton, Elk Grove, Sacramento. I’ve seen estimates that in low water years as much as 10% of the flow that feeds into the huge pumps has been treated and released into the Delta.
For Zone 7 water users, the Delta provides as much as 80% of water in a normal year. Reuse is typical elsewhere in the country where cities take water from rivers on the upstream side, use it, treat it and then put it back in the river.
You’re not drinking pristine snow melt unless you live in an area served by the San Francico Public Utilities Commission’s Hetchy Hetchy project near Yosemite or the East Bay Municipal Utility District’s Mokelumne River supply. Both cross the Delta in large enclosed pipes.
In Orange County, the drinking water comes from wells. The public agencies refill the aquifers with treated effluent that perks into the ground. We’re doing something similar, although without the injection.
When the Dublin San Ramon Services District started making recycled water available for landscape use in the purple pipes, regulators required Zone 7 to build a reserve osmosis plant (at the corner of Stoneridge Drive and Santa Rita Road) to ensure that the minerals in the recycled water do not build up in the ground water. The proposal before the water board adds another layer of treatment so there are no minerals left and allows immediate potable use.
In California, irrigated agriculture uses about 80% of the water. Depending upon what’s growing, it is worthwhile to pump ground water for trees and some vines. Not so for row crops. The cost and availability of water is why there’s very little cotton grown now in California when there were hundreds of acres 20 years ago. That’s been replaced by almonds, a leading export.
Two major water supply projects also should be mentioned. The long-awaited Sites Reservoir near Corning in Northern California is slowly moving ahead. It is an off-stream facility like the San Luis Reservoir in Los Banos designed to take water during high flows and then release it when needed in the fall.
The other controversial project also moving ahead with an approved environmental impact report is the Delta tunnel that would take Sacramento River water at high flows and deliver it directly to the pump forebays near Tracy.
It’s important to note that the State Water Project always was planned with a Delta diversion instead of forcing rivers to flow north-south instead of the natural east-west direction. The key metric about the huge pumps is how many cubic feet per second the San Joaquin River is flowing backward toward the pumps.
These state water wars, between powerful interests, have raged since the 1970s and Jerry Brown’s first stint as governor. He couldn’t move it forward with a second eight-year shot. The late Sen. Dianne Feinstein worked on it at the federal level.
Legal actions already have been filed so nothing will happen while it wends its way through the courts.
Editor's note: "Tim Talk" is a blog written by Tim Hunt, a native of Alameda County. Hunt spent 39 years in the daily newspaper business and wrote a column for more than 25 years in addition to writing editorials for more than 15 years.