Lake Tahoe Water Quality
- 01 | Still One of the Purest Lakes In the World (for now)
- 02 | Why Lake Tahoe Is Dying
- 03 | The Rapid Decline of Lake Tahoe’s Legendary Water Clarity
- 04 | Contaminants Affecting Lake Tahoe Water Quality
- 05 | Climate Change Effects on Lake Tahoe
- 06 | Programs to Protect Lake Tahoe Water Quality
- 07 | How to Protect Your Family from Contaminants In Lake Tahoe Drinking Water
Lake Tahoe is famous for its pristine waters, but it might not stay that way for long…
Over the last few decades, the lake and surrounding watershed has been deteriorating.
Part of the problem is global warming, but the real problem is human activity.
Just how good (or bad) is Lake Tahoe’s water quality these days?
Keep reading to learn about the current state of the lake, plus how to protect your family from harmful contaminants.
Lake Tahoe has some of the purest drinking water in the world.
That’s because 65% of the lake’s water comes from small tributaries and 315 miles of watershed – the other 35% falls straight into the lake as rainfall.
Combine that with a high elevation, and it’s no wonder why Lake Tahoe is so pure.
How pure is it, exactly?
Lake Tahoe contains only 60 parts per million (ppm) of impurities, compared to typical tap water which has 200-400 ppm on average.
The lake’s sheer size helps by diluting any contaminants near the surface.
It holds about 41 trillion gallons of water (yes, trillion with a T), covers 191 square miles, and is the second deepest lake in the country.
With that said, Lake Tahoe water quality isn’t without problems…
Before the 1950s, Lake Tahoe was nothing but a wilderness retreat for adventurous souls.
Since the 1950s, it has transformed into a world famous vacation destination.
The development of homes, hotels, casinos, and ski resorts has really taken a toll on the lake’s pristine conditions.
The main challenge facing Lake Tahoe?
Sediment and algae issues.
This is thanks to a build-up of nutrients like nitrogen and phosphorus in the water, and it’s having devastating effects on the ecosystem.
Since 1968, Lake Tahoe’s deep water clarity has declined from about 100 ft to 70 ft.
In other words, the water gets murky about 30 ft shallower than it used to.
Unfortunately, issues like pollution, algae growth, and sediment erosion have led to a significant reduction in the lake’s clarity.
Near the shore, invasive plants and animals have made the problem even worse.
Asian clams, for example, are an invasive species that release large amounts of nitrogen and phosphorus into the water and feed algae growth.
High levels of algae damage the ecosystem by depleting the water of oxygen and suffocating aquatic wildlife.
At the same time, thick algae can block sunlight from reaching aquatic plants.
Some of the main sources of excess sediment, nitrogen and phosphorus in the water are:
- Urban runoff
- Atmospheric deposition
- Forested upland runoff
- Stream channel erosion
- Destruction of wetlands
- Wastewater
Since the early 1970s, the government has pumped large amounts of wastewater out of Lake Tahoe’s watershed to try and reduce the amount of nitrogen and phosphorus.
However, reducing nitrogen and phosphorus is only a small part of restoring Lake Tahoe water quality…
News flash:
Lake Tahoe’s record-setting pure water still contains some super nasty contaminants.
We pooled the data from the Environmental Working Group’s reports on four major Lake Tahoe water utilities:
- South Tahoe PUD
- City Public Utility District
- Tahoe Keys Water Company
- Tahoe Park Water Company.
The EWG is a non-profit environmental watchdog group that reports results from water quality reports across the country.
Overall, their health guidelines are much stricter than the federal government’s.
The EWG found nine contaminants above their health guidelines by the following amounts:
- Arsenic: 663x
- Chromium (hexavalent): 16x
- Haloacetic acids (HAA9): 5.7x
- Nitrate and nitrite: 11x
- Radium: 23x
- Radon: 483x
- Total trihalomethanes (TTHMs): 12x
- Uranium: 12x
- Tetrachloroethylene: 72x
They also detected low levels of several other contaminants, including:
- Bromide
- Chlorate
- Fluoride
- Haloacetic acids (HAA5)
- Molybdenum
- MTBE
- Strontium
- Vanadium
Let’s take a closer look at the top contaminants threatening Lake Tahoe water quality, and the health risks associated with them…
Arsenic is a natural compound in the earth’s crust, but it’s highly toxic in its inorganic form.
Inorganic arsenic is a byproduct of manufacturing and industrial processes.
Humans can be exposed to high levels of arsenic by drinking contaminated water and eating contaminated food.
Arsenic occurs at higher levels in groundwater in certain parts of the world.
In the case of Lake Tahoe, however, most of the arsenic contamination comes from irrigation of crops with contaminated water.
Long-term exposure to arsenic in drinking water can cause side effects like:
- Cancer
- Skin lesions
- Cardiovascular disease
- Diabetes
Worst of all, in utero and early childhood exposure can have negative impacts on cognitive development.
Chromium-6, or hexavalent chromium, is a highly toxic metal.
Unlike arsenic, which is colorless, chromium discolors water and turns it yellow in high concentrations.
However, even at low levels chromium is linked to increased risks for stomach cancers.
The federal limit for total chromium in drinking water is 0.1 mg/L, which includes chromium-6 and the slightly less dangerous chromium-3.
Unfortunately, there are no federal regulations for chromium-6 on its own.
To make matters worse, the maximum contaminant limit for chromium was set in 1991 and hasn’t been updated since.
Disinfection byproducts (DBPs) are toxic compounds that form when chlorine mixes with organic matter in water.
In a recent report, the Environmental Working Group found unhealthy levels of the DBPs total trihalomethanes (TTHMs) and haloacetic acids (HAA9) in Lake Tahoe’s Water.
Long-term exposure to DBPs may increase the risk of cancer and cause liver damage and decreased nervous system activity.
Studies show that exposure to trihalomethanes may increase the risk of bladder.
On top of that, several studies indicate that exposure to DBPs during pregnancy may have negative effects on fetal growth.
Radium is a naturally occurring radioactive element in rocks and soil.
It can also be present in groundwater and eventually make its way to surface water sources.
On the south end of Lake Tahoe, the EWG found 23x safe levels.
Fortunately, only a small portion of radium gets absorbed into the digestive tract when you drink contaminated water – the rest passes through the body and exits through the urine.
However, the radium that does get absorbed behaves like calcium and is stored in the bones.
Radium exposure can also increase the risk of:
- Weakened immunity
- Anemia
- Cataracts
- Fractured teeth
- Bone, liver and breast cancer
The federal limit for radium is 5 picocuries per liter (pc/L), but the EWG believes that this is way too low based on current medical research.
Radon is another radioactive element that contributes to carcinogenic radiation in the environment.
Levels were a whopping 483x higher than the EWG’s health guidelines in their recent report.
Out of all the radioactive elements, radon presents the biggest risk to human health.
According to a recent report by the National Research Council, roughly 19,000 deaths a year are linked to radon exposure.
Although these deaths are mainly due to radon in smoking tobacco, radon can enter water through the migration of soil gas and is a public health concern in drinking water.
Uranium, like radium and radon, is a radioactive element found in the rocks, soil, and groundwater.
Over time, it has made its way into lakes throughout the country, including Lake Tahoe.
- Kidney damage
- Bone deterioration
- Weakened immunity
- Hypertension
- Heart disease
Nitrate is a common ingredient in fertilizers that promotes plant growth.
As you discovered earlier in this article, high nitrate levels are one of the main reasons for destructive algae growth in Lake Tahoe.
Unfortunately, consuming too much nitrate in drinking water can be harmful.
The greatest danger is for infants under six months old.
Baby formula made with nitrate-contaminated water can cause a life-threatening condition called methemoglobinemia, or blue baby syndrome.
The nitrate prevents the blood from carrying oxygen, turns the skin blue, and starves the cells of oxygen.
In adults, signs of nitrate poisoning include:
- Increased heart rate
- Decreased blood pressure
- Headaches
- Stomach cramps
- Vomiting
Some studies also show that nitrate can increase the risk of gastric cancer.
Adults are more at risk of nitrate poisoning if they have pre-existing conditions like heart disease, anemia, and lung disease.
Phosphorus is another key ingredient in soil and fertilizers that supports plant growth.
It also feeds damaging algae growth in Lake Tahoe.
Phosphorus is essential for plant life, but too much of it can starve the water of oxygen and throw the entire ecosystem out of balance.
In some cases, toxic blue-green algae blooms can be harmful to humans and pets.
Drinking or swimming in contaminated water can cause symptoms like:
- Nausea
- Vomiting
- Diarrhea
- Headaches
- Dizziness
- Skin irritation
Pet and livestock deaths are common if the animals drink large amounts of the water containing algae blooms.
Tetrachloroethylene, also known as perchloroethylene, is a colorless liquid used in dry cleaning.
It is also sometimes used as a brake cleaner in cars and trucks.
Over time, it can enter surface water through stormwater runoff.
In their recent report, the EWG found trichloroethylene levels to be 72x above the recommended health guidelines.
What happens to your body when you consume tetrachloroethylene?
According to the International Agency for Research on Cancer, it is a Group 2Z carcinogen, meaning it probably increases the risk of cancer in most humans.
It is also a central nervous system depressant, causes skin irritation, and may increase the risk of Parkinson’s disease.
Global climate change isn’t making things much easier on the Lake Tahoe Basin.
As temperatures rise, it ripens conditions for algae growth.
According to the Tahoe Environmental Research Center, in 2015 “only 6.5 percent of [precipitation] fell as snow, the lowest amount ever recorded,” and that “in the past four years… the lake has warmed at an alarming rate that’s 15 times faster than the long-term warming rate.”
The overall effect is that too many nutrients accumulate in the lake early in the season.
As a result, it throws the entire ecological balance out of whack.
Fortunately, local and nationwide agencies aren’t just standing by and watching the lake die.
There are tons of programs to try and preserve Lake Tahoe water quality.
For example, the Nevada Tahoe Resource Team is improving water clarity with restoration projects on the Nevada side of the Lake Tahoe Basin.
Their goal is to reduce the amount of nitrogen, phosphorus, and sediment entering the lake.
By the year 2076, they want to restore the lake's historic water clarity to 100 ft.
Steps are also in place to control invasive species of clams, shrimp, and aquatic plants.
Every year, the Lake Tahoe License Plate Program raises approximately $350,000 for monitoring and research projects for the lake.
To address issues related to climate change, the Environmental Improvement Program (EIP) established a Sustainable Communities Program.
Plans are in place to expand the stormwater management and erosion control projects to handle larger volumes of runoff during peak flows.
However, as hard as they might try, the chips are stacked against them.
Will their efforts be enough to keep Lake Tahoe drinking water safe?
Lake Tahoe residents should be proud of their world-class water!
Sadly, though, Lake Tahoe water quality is on the decline, and it has been for decades.
Even if they succeed in restoring the water’s clarity, there’s still dangerous contaminants like arsenic, radon, radium, and uranium.
And yep, all of these are linked to cancer!
Fortunately, there’s a simple, affordable solution…
Reverse osmosis (RO) water filtration systems can remove up to 99.9% of all harmful contaminants, and they fit neatly under the kitchen sink.
RO works by forcing highly pressurized water through a very fine, semipermeable membrane.
Even the hardest-to-remove pollutants can’t sneak through!
They also combine several other stages of purification, including:
- Sediment filters to remove dirt, rust, dust and debris
- Activated charcoal filters to remove chlorine and improve the taste of the water
- Ion exchange resins to remove excess hard minerals
- Polishing filters to remove any remaining contaminants
- Remineralization to add healthy amounts of minerals back into the water
Cloud Water Filters also use built-in software to track and monitor your water quality 24/7 through an app on your phone.
Are you ready to return Lake Tahoe tap water to its former glory?
