Nearly one-fifth of the raw groundwater used for public drinking water systems in California contains excessive levels of potentially toxic contaminants, according to a decade-long U.S. Geological Survey study that provides one of the first comprehensive looks at the health of California’s public water supply and groundwater.
One of the surprises in the study of 11,000 public supply wells statewide is the extent to which high levels of arsenic, uranium and other naturally occurring but worrisome trace elements is present, authors of the study said.
Public-water systems are required to bring many contaminants down to acceptable levels before supplying customers. But the findings highlight potential concerns involving the more than 250,000 private wells where water quality is the responsibility of individual homeowners, state officials said.
Several million Californians rely on public water systems in which raw supplies bear potentially toxic amounts of those trace elements, according to the first cumulative findings of the state and federal Groundwater Ambient Monitoring and Assessment program, which California created in the early 2000s.
The survey also gives public-policy-makers the first sweeping look at the extent to which agricultural irrigation, industrial pollutants and other uses of groundwater are adding to problems for underground water reserves, now under heavy demand in California’s drought.
Uranium, for example, is a naturally occurring element — one that can raise the risk of kidney ailments and cancer if consumed long-term at high levels.
But farm irrigation draining into underground water aquifers has contributed to uranium showing up at unsafe levels in 7 percent of public water supplies in the farm-rich San Joaquin Valley, the study found.
For California’s water managers, “the challenge right now, of course, is the drought,” said John Borkovich, an official with the state Water Resources Control Board who helps oversee the groundwater monitoring program. “Being able to sustain delivery of a safe water supply is the No. 1 concern, of course. But water quality is hand in hand with water quantity.”
Water problems with clear culprits, such as oilfield injection into water aquifers, are comparatively easier for regulators to handle, Borkovich said. For broader patterns of contamination with no single offender, however, “it’s up to the Legislature to decide whether or not there needs to be more attention paid to the results we’ve found,” he added.
The findings, published by the Environmental Science & Technology journal of the American Chemical Society, draw on data from state monitoring of public supply wells and from well testing by the U.S. Geological Survey and others. A public water supply is any source serving three or more people.
Statewide, about one-third of the state’s drinking water comes from groundwater in public supply wells.
In California’s Central Valley, groundwater contaminated with uranium, arsenic or nitrates at several rural schools in Tulare County has put drinking fountains off limits to pupils.
“You could call it a headache,” said Terri Lancaster, principal and superintendent at Waukena Joint Union Elementary School, a district surrounded by rich farmland.
Before winning a state grant this year, the district, with 260 students, spent $10,000 or more annually to buy drinking water, she said. Her staff has to order the bottled water, store and distribute it to each classroom, and recycle the empty bottles.
The newly released study looked for contaminants present in raw water supplies above legally set thresholds.
For contaminants without any legally set limits, the survey looked for levels at or above thresholds identified as potential concerns for human health.
By law, public water systems with a well that consistently shows unhealthy levels of contaminants are required to notify customers and fix the problem, said Kurt Souza of the State Water Resources Control Board’s division of drinking water.
Solutions often involve diluting contaminated water with a clean source, or drilling a new well.
The study managed to examine supplies for 99 percent of Californians using public water systems, said Kenneth Belitz, lead author on the report and now the head of the groundwater portion of U.S. Geological Survey’s National Water Quality Assessment Program.
A total of 8.9 percent of Californians drink from public water systems where groundwater in its raw form bears excessive levels of potentially toxic trace elements, the study found.
Another key finding showed that unsafe levels of nitrates from fertilizer cloud raw groundwater supplies for only 5.6 percent of Californians on public water systems— but almost all of them are in former farmland long ago converted to suburbs, Belitz said.
The high readings from former farmland in Northern California’s Livermore Valley and Southern California’s Santa Ana basin underscore that it can take decades for contamination to show up in public water systems, Belitz said.
In places such as the Central Valley that are now heavily agricultural, nitrates from fertilizer might be “something that in the future … people will be dealing with,” he said.
Makati1 on Wed, 15th Jul 2015 8:00 pm
This is not a surprise. Most water of all kinds is polluted with something. Especially in the industrial world. Even well water in an area surrounded by farms is likely polluted with nitrogen fertilizer and chemical weed and bug killers. If your water comes from rivers, it may even have drugs in the mix.
I can remember streams running red with carpet dies and the Susquehanna River flowing with raw sewage not more than 50 years ago. And not being able to see above the 15th floor of buildings in the steel city of Pittsburgh was common, due to air pollution. Then we sent all of that to Asia, along with our jobs and future. Now the water and air seem clearer, but that is only in appearance, not reality.
Rodster on Wed, 15th Jul 2015 8:49 pm
Speaking of water, our buddies over in China are having a water crisis of their own, actually for sometime now. Lets hope they handle it better than their stock market bubble or they’ll be yelling Ho Lee Fook.
http://www.zerohedge.com/news/2015-07-15/forget-stocks-china-trying-centrally-plan-its-way-out-another-black-hole
Makati1 on Wed, 15th Jul 2015 9:27 pm
Might want to check this out…
http://www.usatoday.com/story/news/nation/2015/07/10/el-nio-unlikely-quench-california-deserts-thirst/30001177/?utm_source=feedblitz&utm_medium=FeedBlitzRss&utm_campaign=usatoday-newstopstories
And this:
http://www.npr.org/2015/07/11/421995880/wildfires-in-canada-and-alaska-drive-thousands-from-homes?utm_medium=RSS&utm_campaign=environment
And this:
http://www.dailytimesgazette.com/buzzkill-shrinking-bumblebee-range-threatens-food-security/18432/
Reality is a bitch…
BobInget on Thu, 16th Jul 2015 10:28 am
Monday we read:
Northern Cal’s Lake Shasta, a man’-made irrigation reservoir is so low fishermen are strongly advised not to eat their mercury contaminated catch.
Wednesday, most of the water for central valley
mellon and veggies come directly from Lake Shasta.
Filtration, the same methods used for desalination are available but impractical for
agriculture. Low reservoir levels have exposed heavy metals once too deep to be a problem.
Now farm LAND in the Central Valley may become permanently contaminated.
Mercury is no joke. I’m concerned.
drwater on Thu, 16th Jul 2015 1:14 pm
Bob,
Mercury at the water concentrations mentioned is not a problem for irrigation water or even drinking water. It is a problem in fish because it bioconcentrates as it moves up the food chain from tiny critters to small fish to big fish.
BobInget on Thu, 16th Jul 2015 6:56 pm
Thanks Dr Water.
I’ve been told in drought situations, irrigation water used exclusively can lead to salt build-up.
Just wondering if over time heavy metals also could accumulate in soils.
I’ll bet lots depend on the manner water application, flood, sprinkler, top drip, buried
tee tape etc. Also some plants like melons are more water intensive then say deep rooted grapes. Top watering during daylight hours causes evaporation. Do salts and heavy metals evaporate into the air? If not where do they go when many acre feet of water per year are applied?
Which plants filter out sewage contaminants
best? Medicines; hormones, (birth control) antibiotics, cleaning products, (phosphates)
human and animal manure, radio active compounds, oils, heavy metals? Even if plants ‘ignore’ individual contaminants, how about when several combine to form entirely new chemicals?
By this time next year or the year after, Shasta may dry up making speculation moot.
From a subduction zone near NorthWest Resident.
Makati1 on Thu, 16th Jul 2015 8:36 pm
Logic tells you that heavy metals will be picked up in all kinds of plants in some amount. Add in all of the other chemicals in the sludge in the lake bottom, stirred up by low water levels, and you have a poison cocktail. Humans have been dumbing down themselves by ingesting heavy metals and all kinds of other toxic substances since the age of hydrocarbons began that allowed all of them to be released in huge amounts into the ecosystem.
Not to mention what those substances will do to the millions of tiny animals and microscopic organisms, in one cubic foot of soil, that are required to make it fertile. Kill them off, and you have sand. the ecology that keeps us alive, is a very complex system that we are destroying with our stupidity and greed.
Kenz300 on Fri, 17th Jul 2015 5:12 am
We all need clean air to breath and safe water to drink………
Pollution of any kind needs to be restricted.
apneaman on Fri, 17th Jul 2015 1:36 pm
The California Drought Is Just the Beginning of Our National Water Emergency
For years, Americans dismissed dire water shortages as a problem of the Global South. Now the crisis is coming home.
http://www.thenation.com/article/the-california-drought-is-just-the-beginning-of-our-national-water-emergency/
apneaman on Fri, 17th Jul 2015 4:31 pm
They Make Water Out of Sludge in Sao Paulo Now
“With El Nino settling into a strong-to-monstrous mode and with the world now baking under 1 C of global temperature increases since the 1880s, a large swath from South American through to the Caribbean is suffering from extreme drought.”
Water From Sludge
“But, in all this wide-ranging drought, there are few places where the situation is so acute as it is in Sao Paulo, Brazil. There, the drought is so severe that it has inflicted water rationing on the populace ever since early 2014. A situation that has gone from bad to steadily worse. At the epicenter of these losses is a massive reservoir called the Cantareira. A great lake once filled with enough reserves to supply over 6 million people that has been reduced to what amounts to a giant, drying puddle of mud. A situation that has forced water managers to pump sludge from the Cantareira’s previous dead pool zone and into treatment facilities in order to provide water to Sao Paulo citizens”
https://robertscribbler.wordpress.com/2015/07/17/they-make-water-out-of-sludge-in-sao-paulo-now/
apneaman on Sun, 19th Jul 2015 2:08 pm
Come hell or high water: The disaster scenario that is South Florida
http://www.theglobeandmail.com/news/world/come-hell-or-high-water-the-disaster-scenario-that-is-south-florida/article25552300/