How far, how fast and in which direction does polluted water from the Tijuana River travel when it hits the coastline?
“It depends on the waves, it depends on the winds, it depends also on the tides,” says Falk Feddersen, a scientist at the University of California Scripps Institution of Oceanography.
In 2015, Feddersen and his colleague Sarah Giddings led a binational team in a project that involved injecting an environmentally safe pink dye into the ocean at several points near the U.S.-Mexico border, tracking the plumes as they spread.
Under certain conditions, they found contamination can potentially travel for miles up the coast to Imperial Beach and beyond.
This typically occurs when the waves are coming from the south, a condition known as south swells.
Especially in late summer, when there are south swells and the winds are lighter, “oftentimes these plumes can be trapped very close to the coast,” Feddersen said.
This condition is more typical in winter months.
On average, the plume tends to travel more to the south than to the north, Feddersen’s model shows: “Long-term, would you rather be surfing in Playas de Tijuana or Imperial Beach?
You’d rather be surfing in Imperial Beach.” But also on average, “you definitely don’t want to be south of that plume in winter,” if contaminated water hits the coastline, he said.
But if spills occur in summer months, Feddersen said, “probably you don’t want to be north of that plume in summer on average, because on average the waves come from the south and the winds are lighter.”

Researchers release a warning on plastics found in water bottles.
A recent study found that 93 percent of bottled water contained signs of contamination with microplastics.
More than just water However, it’s not just bottled water that health experts are worried about.
A number of industrial and consumer products made of plastic contain endocrine-disrupting chemicals (EDCs), which can negatively impact human health.
EDCs are chemicals found in a number of everyday products that can interfere with hormones.
Even in low doses, they can lead to a number of abnormalities in the body.
And that’s just one of many chemicals.
Affecting future generations A recent study by the Endocrine Society found that the impact of EDCs could extend beyond more than one generation by contributing to a significant drop in sperm count and sperm quality.
Researchers said this suggests prenatal exposure to DEHP can impact both fertility and reproductive capacity of more than one generation.
This, coupled with controversy surrounding the safe doses of various EDCs, has impacted the development of federal regulations and guidelines.

“Overall, this study informs a more directed approach to increasing compliance with drinking water quality regulations,” says author Maura Allaire, UC Irvine assistant professor of urban planning & public policy.
“Identifying hot spots and vulnerability factors associated with violations can allow public policies to target underperforming water systems.” While serious violations like those in the Flint, Michigan, crisis are rare, ensuring reliable access to safe drinking water poses challenges for communities across the country, according to a recent study led by the University of California, Irvine.
Researchers found that between 1982 and 2015, 9 million to 45 million people annually were affected by water quality issues — and that low-income, rural regions were most vulnerable.
Infractions were more numerous in “hot spots” in Texas, Oklahoma and Idaho, suggesting that these systems struggle with recurring problems.
Not all infractions pose immediate health concerns, but drinking water contaminants can cause short-term illnesses such as gastroenteritis, as well as chronic conditions including cancer and neurological disorders.
Identifying hot spots and vulnerability factors associated with violations indicates the types of communities that can benefit from greater regulatory oversight and assistance to help reduce quality issues, improve compliance and ensure safe drinking water across the nation.” Study results appear in the early online edition of the Proceedings of the National Academy of Sciences for the week of Feb. 12.
Compliance is associated with purchased water sources and private ownership.
Purchased water is supplied by wholesale agencies, which have greater resources to meet federal standards, while private utilities have considerable assets at stake should they deliver poor-quality water and subsequently face lawsuits or takeover by a municipal government.
“Public policies that target underperforming utilities include prioritization of technical guidance and financial support,” Allaire said.
And, where feasible, purchased water contracts and consolidation of systems could provide a way to achieve economies of scale for improved treatment technologies.” Haowei Wu, Upmanu Lall, and Alan and Carol Silberstein of Columbia University contributed to the project, which received a NatureNet Science Fellowship, a National Science Foundation award (No.

KNOX COUNTY, Ky. (WKYT) The Knox County Utility Commission has issued a system-wide boil water advisory for its water customers.
They say that flooding has washed out several water lines in the county.
They say there is a slight chance of contamination due to the loss of pressure.
This includes the Artemus, Himyar, Bimble, Flat Lick and Stinking Creek areas.
If you get water from Barbourville Utilities, you are not affected.
K.S.P.
Post 10 is asking motorist to use caution if traveling today in Knox County.
Numerous roads are completely cover with water.
#TurnAroundDontDrown pic.twitter.com/1KgcnRSFbK — Trooper Jacobs (@TprJacobs) February 11, 2018

Why do some trees die in a drought and others don’t?
Scientists from the University of California, Davis, and colleagues examined those questions in a study published in the journal Ecology Letters.
Using climate data and aerial tree mortality surveys conducted by the U.S. Forest Service during four years (2012-2015) of extreme drought in California, they found that when a drought hits the region, trees growing in areas that are already dry are most susceptible.
The research also showed that the effects of drought on forests can take years to surface, suggesting that such effects may linger even after the drought has ended.
Southern Sierra Nevada trees are most vulnerable The study said that trees in the driest and densest forests are the most at risk of dying in an extreme drought.
‘How much drought a tree can take’ "Our analysis found out how much drought a tree can take," said UC Davis Ph.D. student Derek Young, who co-led the study with Jens Stevens, a UC Davis postdoctoral researcher during the study who is currently at UC Berkeley, and Mason Earles, a postdoctoral researcher at Yale University.
The U.S. Forest Service aerial tree mortality surveys in 2015 estimated 29 million trees in California had died after four years of extreme drought.
Long-term climate and competition explain forest mortality patterns under extreme drought.
ScienceDaily, 19 January 2017.
Retrieved June 16, 2017 from www.sciencedaily.com/releases/2017/01/170119143406.htm University of California – Davis.

UCLA-led researchers track groundwater loss during drought in California’s Central Valley.
Crops like almonds cannot be left fallow during dry years without jeopardizing the trees, which during droughts require extensive irrigation in the California Central Valley.
“So, we’re talking about 40 times that amount in the recent drought.” During droughts Central Valley farmers are forced to use wells to replace water that would typically come from the Colorado River basin and the Sierra Nevada mountains.
Higher temperatures during the more recent drought period and the transition from row to tree crops, accounted for most of the increase in groundwater loss between the two droughts, and more than offset the effects of a reduction in irrigated land, Lettenmaier said.
Groundwater usage for crop irrigation in the Central Valley is a well-documented and hot-button issue in California.
Researchers used two methods to track groundwater levels, traditional water balance estimates —which take into account surface water inflow like rainfall and snow melt, soil moisture capacity and evapotranspiration — and data from NASA’s twin satellite system called GRACE (Gravity Recovery and Climate Experiment).
GRACE estimates align with the water balance estimates, with some variance.
GRACE data estimates that groundwater loss from 2012 to 2016 was 11.2 cubic kilometers per year, compared to water balance estimates of 10 cubic kilometers per year.
“Although both water balance-based and GRACE-based groundwater volume estimates are subject to errors, the relatively small area of the Central Valley in the eyes of GRACE might also be responsible for that recovery discrepancy,” Lee said.
Researchers hope future studies will address how much actual recovery happened between droughts and whether recovery from the most recent drought is on track to replenish the system.

THIS JUST IN … New Report Shows 74 Percent of California’s Native Salmon, Steelhead and Trout Likely to Be Extinct in 100 Years, 45 Percent in 50 Years if Trends Continue.
From Cal Trout: Fish and watershed advocacy group California Trout (CalTrout) and University of California Davis, Center for Watershed Sciences, provided key results from an in-depth report today detailing the status of 32 types of salmon, steelhead, and trout that are native to California.
SOS II: Fish in Hot Water is the second such report released by CalTrout and the UC Davis Center for Watershed Sciences.
“Declining fish populations indicate degraded waters, which threaten the health and economic well-being of all Californians.” If present trends continue, 74 percent of California’s native salmon, steelhead, and trout species are likely to be extinct in 100 years.
Thanks to ongoing scientific research, we now know what to do – and where – to improve the plight of native fish.” The report includes an analysis of key threats to the survival of each species, starting with the overarching threat of climate change, which is likely to reduce the availability of cold water habitat that salmon, steelhead, and trout all depend on for survival.
Restoring function to once productive – but now highly altered – habitats can greatly improve rearing conditions for juvenile fish, especially floodplains, coastal lagoons, estuaries, and spring-fed rivers.
Additionally, SOS II: Fish in Hot Water identifies three science-based strategies to support a return to abundance for California’s native salmonids: First, focus on opportunities to mimic natural processes within altered landscapes.
The UC Davis Center for Watershed Sciences has been conducting problem-solving research on conservation and water management issues since 1998.
Key Facts from State of the Salmonids II: Fish in Hot Water 45 percent of California’s salmon, steelhead and trout are likely to be extinct in the next 50 years if present trends continue.
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Solar Powered Condenser Turns Ambient Humidity into Drinking Water.
MIT and UC-Berkeley Scientists recently demonstrated a new device designed to collect water straight from ambient air using only solar power.
This water harvester can even pull moisture in desert climates where humidity is as low as 20 percent.
At any moment, it’s estimated that atmosphere contains about 3,100 cubic miles of water vapor, which is enough to cover the entire surface of the Earth with one inch of water if it fell all at once.
In addition to its most visible form, clouds, atmospheric water is also present in clear air and the entire system is recycled every nine days.
Solar Powered Condenser; Off-Grid Water Harvester Researchers at MIT, in collaboration with the University of California Berkeley, have developed a prototype for a device that pulls water from clear air using solar power.
The device, reported in the journal Science, is an open air chamber containing a lattice-like structure made from a metal-organic framework (MOF), produced at the UC-Berkeley.
By the same year, two-thirds of the global population could be living under water-stressed conditions.
Developing solutions to sanitize water and produce it where it is scarce is a major challenge for many countries.
And there’s no resource more accessible than ambient air.

He and other students believe that completely eliminating the sale of disposable plastic water bottles on campus is the only way to achieve zero waste by 2020.
"We want to ban the sale of plastic water bottles because plastic is the No.
1 threat to marine ecosystems," said Mnatsakanian.
"Bottled water plants negatively affect surrounding communities, and annual purchases of bottled water are 2000 times more expensive than using tap water.
On top of that, tap water has significantly lower rates of potentially damaging substances."
The ban on plastic water bottles isn’t the first campaign aimed at decreasing their presence on campus.
"Breaking the Plastic Habit" was an SSC campaign in 2011 that pledged to eliminate the sale of plastic water bottles in dining halls and resulted in the installation of the first 10 hydration stations on campus.
The All Campuses Plastic Water Bottle Ban campaign plans to implement lasting policy not only at UC San Diego, but all UC campuses.
"Thanks to years of working with campus administration, UC San Diego Plastic Water Bottle Ban campaign leaders now have the expertise to teach student environmentalists at other campuses how to implement changes," said Mnatsakanian.
During this year’s event, Mnatsakanian directed Student Sustainability Collective leaders from campuses around the country about bypassing initiatives and aiming straight for policy changes.

This solar-powered device harvests water from dry air.
Scientists at MIT and UC Berkeley have created a prototype that does just that — and it only requires 20-30 percent humidity to work.
MOFs are compounds created by combining metals with organic molecules.
In this case, Yaghi and his team at Berkeley created a MOF that binds to water.
It’s a passive device, requiring no other energy source than the sun — and doesn’t even need very bright sunlight to function.
Both Yaghi and Wang believe they’ve barely tapped the concept’s potential.
Future MOFs might be able to absorb 40 percent or more.
Freshwater scarcity is a global problem of immense proportions that does not receive nearly the attention that it should.
Recent estimates show that 4 billion people — that’s two-thirds of the world’s population — experience acute water scarcity at least one month of the year.
California’s historically severe drought has finally just ended, but the state typically experiences big fluctuations in rainfall from year to year.