May/June 2022 - 22

in spite of the fact that many of these
brackish groundwater reserves are
actually growing, unlike freshwater
reserves that are shrinking.
And then,
along the
coast, we
have significant seawater intrusion
in many, many places - Ventura
County, Morro Bay and Salinas, just
to name a few. Seawater intrusion in
Salinas extends over 5 miles inland
now at certain points, with many
agricultural wells becoming unusable.
Now, according to a profound new
hydrological modeling study just
recently carried out in Ventura
County, these impacted areas could
actually be turned into major new
sources of area water, with the
modeling
showing
Tail water is produced in the prevention of fields becoming waterlogged, and is often full of
fertilizer runoff and problematic minerals.
The answer is emphatically no!
SGMA also allows for the creation
of new water supplies as an alternate
path to bringing basins into balance.
Although most people think that
means building new dams, or
undertaking more water banking
and recharge activities, there are lots
of other ways to create new water
supplies in each basin by converting
" bad " or impaired water sources into
new fresh water supplies.
The most important thing to realize
is that while we may be running out
of fresh water - water where total
dissolved solids (TDS) levels are
under 500 ppm - we are definitely
not
running
out
of water
itself.
There are huge potential reserves of
brackish groundwater or otherwise
contaminated water sources across
the state that can now be turned into
new water supplies in cost effective
ways due to disruptive new water
technologies that are just now coming
to market.
This is in part thanks to the focused
efforts of a federally and state-funded
effort called the National Alliance for
Water
Innovation
(www.nawihub.
org/about). This organization is
bringing together water researchers
and business partners from all across
the country to " develop a portfolio
of technologies that enable 90% of
nontraditional water sources to be
22
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treatable at a levelized cost comparable
to today's marginal water supplies. "
The good news is that some of these
research efforts are already actually
bearing fruit - with breakthrough
new desalination technologies now
coming into the marketplace - just
in time to create the substantial new
water supplies needed under SGMA.
To understand
the
being able to use these nontraditional
or " impaired " water supplies, let's
consider California's overall yearly
water deficit. The figures across all
the water basins in the state appear to
suggest that the combined state deficit
is around an average 3 million acre-feet
per year. That figure seems huge.
However,
Stanford University's
Water in the West recently published
a report estimating that California
has perhaps as much as 24 billion
acre-feet of brackish groundwater
across the state.
Twenty-four billion acre-feet is
enough to cover our 3 million acrefeet
per year deficit for the next 8,000
years! As just one example, there
are huge, very shallow quantities of
brackish groundwater down the west
side of California's Central Valley.
But these brackish groundwater
reserves - because they have not
been usable up until now - are
essentially invisible in most basins'
SGMA planning processes. And this is
that
this new
potential of
approach would simultaneously halt
the further progression of seawater
intrusion inland.
Another source of potential new
water supply is that many irrigated
basins in the state have underlying
perforated piping to carry off what is
known as " tail water. " The purpose
of this piping is to keep the farmland
above from becoming waterlogged.
This tail water is frequently full of
fertilizer runoff, and sometimes also
has
naturally
occurring,
but
very
problematic, minerals in it such as
selenium and arsenic. Today in the
Central Valley, this water is channeled
into huge evaporation ponds where
it is evaporated off and lost. In other
places, this water is drained into the
sea. It is now, however, finally practical
to fully clean this water for reuse. We
believe there may be 100,000 AFY or
more of this tail water being wasted
today across the state.
And then there's what is known
as produced water - water that is
naturally mixed with the oil that is
being pumped out of the ground. In
California, there are about 400,000
acre-feet per year of produced water
that could be thoroughly
cleaned
and used for agriculture. We already
have many thousands of acres
in
the state that have been irrigated
with produced water for many
years. Recently published California
university multi-year studies now
show that there are no detectable
harmful impacts on the crops as long

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May/June 2022

Table of Contents for the Digital Edition of May/June 2022