(music)
Hi, my name is Dylan Stern and I'm
excited today to celebrate the 50th
anniversary of Earth Day, and to bring
you some of the science going on right
now to help us better understand and
take care of our planet. At the Delta
Science Program we are charged with
providing the best possible, unbiased
scientific information to inform water
and environmental decision-making in the
Delta. One of our key objectives in
carrying out that mission is to initiate,
evaluate, and fund research. It will fill
critical gaps in our understanding of
the current and ever-changing Bay Delta
system. After all, if environmental
managers and state decision-makers don't
have access to the science they need to
in some critical questions about
managing our natural resources, they're
essentially flying the plane without any
radar. So in the spirit of Earth Day I'd
like to share with you some of the
science being conducted in the Delta,
which plays an important role in helping
to contribute to a healthier, more resilient planet.
The Delta exists at the convergence of
Sacramento and San Joaquin rivers in
Northern California. The Sacramento-San
Joaquin Delta is part of the largest
estuary on the west coast of the
Americas, spanning more than 700,000
acres or roughly the size of the state
of Rhode Island. It also supplies a portion
of the water used by two-thirds of
Californians, or about 27 million people.
The Delta also supports over 3 million
acres of farms that deliver food at home
and abroad. The Delta is also a unique
biodiversity hotspot, one where
fresh water from the mountain
runoff meets saltwater from the San
Francisco Bay and Pacific Ocean. Its
thousands of miles of meandering
waterways and surrounding lands create
ideal habitat for more than 750 plant
and animal species. Furthermore, many
species of birds including waterfowl and
sandhill cranes and also fish, such as
the chinook salmon, delta smelt, Central
Valley steelhead and green sturgeon all
depend on habitats in and around the
estuary for survival. With all of that
said it's no surprise that the Delta and
its resources, like the water that moves
through i,t
are major statewide,
national, and even international
importance. The scale of benefits that
the Delta generates for humans and the
environment underscores the importance
of good stewardship, and a key component
of stewardship is conducting science to
inform management decisions. The Delta was
formed thousands of years ago and for
much of its existence it was stewarded
primarily by the indigenous people of
California. Beginning roughly 150 years
ago an influx of Europeans and Americans
brought by the promise of the gold rush
began reshaping and engineering the
Delta and its waterways. This
re-engineering, coupled with rapid urban
and agricultural growth in this part of
California, have led to a number of major
changes in the Delta, including water
diversions and changes in flow patterns,
large-scale conversion of wetlands to
channels and levies, changes in the
distribution and abundance of native and
endemic animals and plants, the
introduction of invasive species and
pollution from urban and agricultural
areas. These changes in turn have had
direct impacts on cultural resources as
well as the activities that we enjoy in
and around the Delta, including
recreational fishing, boating, and
swimming. Because the stakes to people and
the environment are so high it's
imperative that we take a science,
fact-based approach to figure out
effective ways to manage the Delta and
maintain its numerous valuable services.
One of the key services to maintain in
the Delta is water quality to ensure a
healthy and resilient ecosystem. In order
to properly manage water quality we rely
on waste water treatment plants. They
are important tools for treating the
water from urban and commercial sources
that often contains organic material,
nutrients, bacteria, and toxic substances.
Treatment processes remove most of these
and then the water is returned to the
environment.
Other major sources of pollution include
stormwater and agricultural runoff, which
wash into the Delta during rainstorms
and may negatively impact habitat for
fish, birds, invertebrates, and of course
all the human uses of the Delta. But not
all wastewater treatment plants are
created equal. There are three general
levels of wastewater treatment, depending
on the original quality of the water and
its intended final use. A typical
wastewater treatment process consists of
primary treatment to remove solid
material, followed by secondary treatment
that removes organic material and
nutrients, and sometimes a disinfection
step. Tertiary treatment involves
advanced polishing steps such as
filtration membranes and ozone
treatments. Now the Sacramento Regional
County Sanitation District, a regional
SAN, their wastewater treatment plant is
the largest in the Delta, and it's the
largest inland discharger west of the
Mississippi. It processes about 130
million gallons of wastewater daily,
which would fill nearly 200 Olympic
sized swimming pools each day.
A combination of physical, chemical, and
biological treatment processes,
considered secondary treatment, remove
most pollutants from the wastewater.
Since going online in 1982, regional SAN has demonstrated an excellent record
of regulatory compliance and its
commitment to protecting the environment
and public health. Over ten years ago,
emerging and controversial science
suggested that wastewater from the
regional SAN wastewater treatment plan
resulted in excess nutrients flowing
into the Sacramento River and that the
nutrient ammonium has a negative effect
on beneficial phytoplankton, or tiny
plants in the water that make up the
base of the food web. And this in turn
was linked to the decline of the delta
smelt and other native fishes. It is
widely agreed however that the amount of
phytoplankton in the Delta itself has
declined significantly in recent decades.
And this is a major stressor for the
parts of the food web like zooplankton
mussels and fish that rely on this food
source. This prompted the Central Valley
Regional Water Quality Control Board to
issue a new wastewater discharge permit
requiring significant treatment plant
upgrades. Since 2015
regional SAN has embarked on a 1.7
billion dollar infrastructure
improvement project, entitled the Echo
Water Project. This project involves
enhancing the current secondary
treatment process and adding a tertiary.
Treated water discharge to the
Sacramento River will soon contain 65%
less organic and inorganic nitrogen and
about 93 percent less ammonia. By 2021
this is expected to result in the
largest change in recent decades to
nutrient dynamics in Sacramento River and
the Delta. Today I wish to tell you about
Operation Baseline, an effort to
establish some baseline data on water
quality and the food web before the
wastewater treatment plant upgrade, in
order to answer key questions about the
potential impacts of the upgrade on the
environment. Peter Drucker, an influential
thinker on business and management is
attributed with saying, "if you can't
measure it, you can't improve it." So there
are various ideas about what might
happen to water quality and the food web
following the upgrade, some of which are
actually at odds with each other. If it
is true that ammonium is having a
negative effect on beneficial
phytoplankton, the upgrade could improve
phytoplankton production because the
ammonium will be reduced, which could
help imperiled fish populations. However,
researchers think that it is nearly
impossible to directly measure benefits
to fish populations due to the reduction
in nutrients alone. So science focused on
nutrients and the lower levels of the
food web may have a better chance of
detecting the link. And on the other hand,
recent science suggests that murky water
and invasive clams eating phytoplankton
or actually would make it hard for
phytoplankton to grow.
So in that case, the reduction in
nitrogen after the upgrade could
actually limit phytoplankton growth.
Operation Baseline is capitalizing on
this natural experiment by monitoring
and analyzing environmental
characteristics before and after this
wastewater treatment plant upgrade. So
you might be wondering, why should you
care? Well, if you live in the Sacramento
region, your rate payer dollars are
contributing toward the upgrade and if
you live in the Delta may be curious
about how your environment will change. For example,
the reduction in nutrients might
limit harmful algal blooms, or HABs,
which have become a growing problem in
the last two decades. HABs produce toxins
that make people sick. Both HABs
and invasive aquatic weeds are a nuisance
for recreation, navigation, and animal
habitats in the Delta. Many factors
influence HABs and invasive species
including water flows and temperature,
but the upgrade may reduce the severity
of these problems. And if you live in
other parts of California, it's very
likely that this upgrade you benefit the
water you can drink or recreate in. The Delta
Science Program and other partners have
funded a number of scientific components
that make up Operation Baseline.
They include a conceptual framework that
organizes different ideas or hypotheses
about how to reduce nutrients in the
Delta might cause changes in the
occurrence of HABs, invasive aquatic
vegetation and the amount and quality of
phytoplankton. Also coordinated sampling
at the base of the food web including
flow nutrients, phytoplankton, zooplankton,
and aquatic vegetation. Field sampling
that includes multiple elements and
sampling teams can better capture the
connections between these related
elements and tell a more holistic story.
The US Geological Survey, or USGS,
recently tested a new type of sensor
that can measure the phytoplankton
community quickly, and at the same time
its nutrients are measured. An array of water quality
sensors was used on a boat and flow
through system to literally map changes
in the nutrients across the Delta on a
fine scale. Understanding the amount of
nutrients and type of phytoplankton in
the water tells us whether the food web
is changing
for better or worse. New work directly utilizes
new technologies to better understand
fine scale Delta wide changes in
nutrients and the resulting shifts in
phytoplankton, using a combination of
stationary measurements and for both
the flow through system. This data is
collected at a time and spatial scale
that is relevant to how quickly
nutrients and phytoplankton change in
the Delta, and such information can
produce powerful maps that illuminate
these major differences, hot spots, and
changes in nutrients and phytoplankton.
USGS also developed new methods and
tools to measure nutrients in the
sediments, their forms, and their
movements in and out of the bottom floor
of the Delta. Sediment may play a key
role in controlling nutrient levels in
water we have very little information on.
And this is a key gap for modeling
nutrients in their impacts on the Delta.
The Delta Science Program has also
recently funded another modeling effort
that includes USGS, the Virginia
Institute for Marine Sciences (VINS), and
the Department of Water Resources, who
together will tie together enormous
datasets on nutrients, invasive aquatic
vegetation, and phytoplankton. And this
can for example advance our
understanding and potential management
of the anticipated changes in invasive
aquatic vegetation. Also, VSA
Environmental Services will soon be
analyzing keko plankton, a very small
vitamin, samples coming from across the
Delta.
Currently there is very little data on
this very little phytoplankton, which may
have a disproportionately large role in the food web.
So there are many efforts around the
world to study water quality in the
archaeological effects of upgrading wastewater treatment plants. However,
this effort is quite unique because of
the exciting new technology that's being
used and tested, and because the
complexity of the Delta means that there
are a number of potential unknown
outcomes for the food web. With Operation
Baseline our hope is that researchers
will collect as much information as
possible before the wastewater treatment
plant upgrade occurs, so the same
measurements can be made afterward as
this data cannot be collected after the
fact or replicated in the lab. The
studies are underway now and the results
could help inform other large nutrient
management actions in the Delta as well
as establish new methods that other
large estuary systems could adopt for
similar situations. The science is
intended to supplement existing
monitoring, and to help us gain a better
understanding of nutrients and the food
web in the Sacramento-San Joaquin Delta,
before this opportunity to study a large
scale management change is lost forever.
With that, I encourage you to find out
more about water quality in your own
proverbial backyard, whether it be the
Delta or otherwise. We can all learn more
about how our actions and projects in
their communities are impacting the
environment. Here at the Delta Science Program
this means finding more ways to
support and use new science so that we
can better understand and manage our
impacts to the earth. For more
information, please visit our website
deltacouncil.ca.gov.
Thanks for joining me.
