David Sedlak: 4 ways we can avoid a catastrophic drought
David Sedlak - Civil and environmental engineer
David Sedlak’s research focuses the long-term goal of developing cost-effective, safe and sustainable systems to manage water resources. Full bio
created an amazing system
that made it possible
where there wasn't a lot of water.
of Las Vegas and Phoenix
in a really dry place.
we literally spent trillions of dollars
to get water to our cities.
it was a great investment.
we've seen the combined effects
and competition for water resources
and water resources.
in the lake level of Lake Mead
intakes for Las Vegas high and dry.
a new drinking water intake structure
of the greater depths of the lake.
with providing water to a modern city
to the American Southwest.
city in Australia, Brisbane,
of running out of water.
in São Paulo, Brazil,
completely full in 2010,
the 2016 Summer Olympics.
of the world's great cities,
the effects of a catastrophic drought.
about the navy showers we have to take.
our dirty cars and our brown lawns.
the prospect of turning on the tap
have gotten bad in the past,
to expand a reservoir
of the water resources are spoken for,
to rely on this tried and true way
to solve the urban water problem
with political, legal and social dangers.
the water from our rural neighbors,
the problem to someone else
it will come back and bite us
that already rely upon that water.
to solve our urban water crisis
four new local sources of water
in these new sources of water
that we'll ever run across
without a supply of imported water,
as an unrealistic and uninformed dreamer.
water-starved cities in the last decades
the technologies and the management skills
from imported water,
to tell you about tonight.
supply that we need to develop
that falls in our cities.
of urban development
with concrete and asphalt.
we had to build storm sewers
that fell on the cities out
of a vital water resource.
the volume of water
in the city of San Jose
that fell within the city limits.
of the blue line and the black dotted line
of the water that fell within the city,
to get them through an entire year.
are probably thinking.
is to start building great big tanks
to the downspouts of our roof gutters,
that might work in some places.
where it mainly rains in the winter time
is in the summertime,
to solve a water problem.
of a multiyear drought,
that's big enough to solve your problem.
the rainwater that falls in our cities,
and let it percolate into the ground.
on top of a natural water storage system
huge volumes of water.
Los Angeles has obtained
from a massive aquifer
that comes off of your roof
and flows down the gutter,
"Do I really want to drink that stuff?"
you don't want to drink it
in urban water harvesting
what the city of Los Angeles is doing
in Burbank, California.
the stormwater park that they're building
collection systems, or storm sewers,
into an abandoned gravel quarry.
through a man-made wetland,
into that ball field there
aquifer of the city.
of passing through the wetland
that live on the surfaces of the plants
still not clean enough to drink
this natural treatment process,
of the groundwater aquifers
to solve our urban water problem
of our sewage treatment plants.
with the concept of recycled water.
and the highway median
in a sewage treatment plant.
for a couple of decades now.
from our experience
expensive that we expected it to be.
the first few water recycling systems
and longer pipe networks
in terms of cost.
and practical way of recycling wastewater
into drinking water
we pressurize the water
a reverse osmosis membrane:
to pass through
the viruses and the organic chemicals
cleaves the hydrogen peroxide
are very potent forms of oxygen
through this two-stage process,
known to modern science
the first step in the process,
to the taken-for-granted water supplies
that we recently built
in Southern California.
from a part of the Santa Ana River
almost entirely of wastewater effluent
and San Bernardino.
into our treatment wetland,
the organic chemicals,
and inactivate the waterborne pathogens.
in the Santa Ana River,
and percolated into the ground,
of the city of Anaheim,
from the sewers of Riverside County
of Orange County.
that this idea of drinking wastewater
or not commonly done.
about 40 billion gallons a year
advanced treatment process
the supply of about a million people
will not be a tap at all,
that we manage to do.
about water conservation is outdoors
and other modern American cities,
and our plants survive
to start painting concrete green
and buying cactuses.
landscaping with soil moisture detectors
green landscapes in our cities.
that we need to open up
people say about seawater desalination.
lots of oil, not a lot of water
no matter how you slice it.
of seawater desalination
is hopelessly out of date.
in seawater desalination
in the Western hemisphere
north of San Diego.
Santa Barbara 25 years ago,
will use about half the energy
has become less energy-intensive,
desalination plants everywhere.
a local water supply.
from our reliance on imported water.
our surfaces and our properties,
by about 50 percent,
the water supply by 25 percent.
that makes it into the sewer,
our water supply by 40 percent.
through a combination
and seawater desalination.
to withstand any of the challenges
in the coming years.
that uses local sources
in the environment for fish and for food.
consistent with out environmental values.
and our grandchildren
take care of in the future
to create a new kind of water system.
About the speaker:David Sedlak - Civil and environmental engineer
David Sedlak’s research focuses the long-term goal of developing cost-effective, safe and sustainable systems to manage water resources.
Why you should listen
Author, Professor and Director of the Institute for Environmental Science and Engineering at UC Berkeley, David Sedlak has developed cost-effective, safe and sustainable systems to manage water resources. He is particularly interested in the development of local sources of water, and his research has addressed water reuse–the practice of using municipal wastewater effluent to sustain aquatic ecosystems and augment drinking water supplies as well as the treatment and use of urban runoff to contaminated groundwater from contaminated industrial sites as water supplies.
In recent years, Sedlak's research on the fate of wastewater-derived contaminants has received considerable attention. He began this research in 1996 when he developed simple methods for measuring steroid hormones in wastewater. Since that time, he and his students have studied the fate of hormones, pharmaceuticals, toxic disinfection byproducts and other chemicals. His research team has also studied approaches for remediating contaminated soil and groundwater by in situ chemical oxidation (ISCO) and advanced oxidation processes.
He also is the author of Water 4.0, a book that examines the ways in which we can gain insight into current water issues by understanding the history of urban water systems.
David Sedlak | Speaker | TED.com