Water Quality Resources

NTPUD Annual Consumer Confidence Reports

The District annually publishes a report with information regarding our water supply sources.  Reports are due by July 1 for the year following (e.g. the 2021) Report will be due to the State on July 1, 2022.

NTPUD Annual Drinking Water Information Clearinghouse (DRINC) Report

Source Water Protection

Drink Tahoe Tap

Drink Tahoe TapTahoe Tap is simply the best. Sourced from rain and snowmelt, then minimally treated using state-of the-art disinfection processes, TWSA water purveyors deliver this award-winning drinking water to your home or business, 365 days a year, 24 hours a day, for less than a penny per gallon. Whether you are a local or someone visiting our region, we urge you to kick the bottled water habit, and Drink Tahoe Tap®, instead.

Tap water is better than bottled water when it comes to people’s health, wallets and the environment. Municipal water systems are much more rigorously tested and monitored than the bottled water industry. Food & Water Watch published a report “Take Back the Tap,” which supports findings that bottled water is generally not cleaner, safer or healthier than tap water. Consumers can offset the waste and pollution associated with the single use plastics created by the bottled water industry during production and transportation, with this simple choice.

There are 160,000 public water systems in the United States. 60 systems possess ‘filtration avoidance’ permits. 6 of those systems are at Lake Tahoe; all are TWSA members. This status is only given to systems with outstanding, pure source water, before treatment.

Tahoe Water Suppliers Association

The Tahoe Water Suppliers Association (TWSA) is a Lake Tahoe based partnership comprised of California and Nevada municipal water agencies, dedicated to providing clean and safe drinking water. Our water source is Lake Tahoe, allowing us to deliver some of the finest drinking water in the world.

Protect The Source

Used to supply public drinking water, source water is untreated water from streams, rivers, lakes, or underground aquifers. Land based activities have the ability to pollute water through runoff, trash, and other discharges Source water protection is the safeguarding of drinking water sources from contaminant that are harmful to human health. The water in Lake Tahoe is of excellent quality, and our community treatment plants are designed to remove or inactivate microorganisms, meeting exacting standards . However, emerging contaminants and increases in contaminants quantities often increases the threat of waterborne illness and creates requirements for new and expensive treatment upgrades.

By protecting the source of our drinking water, we reduce the chance of illness and keep water supply treatment costs low. The Tahoe Water Suppliers Association (TWSA) is a Lake Tahoe based partnership comprised of California and Nevada municipal water agencies which are dedicated to providing clean and safe drinking water. Our water source is Lake Tahoe and is considered some of the finest drinking water in the world. Everyone can help protect the quality of our drinking water through simple sanitary practices.

  • Do your part to keep Lake Tahoe clean:
  • Always use the restroom facilities, not the lake
  • Keep diapers out of the water
  • Do not swim if you are sick or just recovering from illness
  • Pick up after your dogs
  • Pick up litter
  • Do not dump portable toilets or holding tanks in or near the lake
  • See a spill or boat sink, call your local Sheriff’s Department
  • Keep all vehicles well-tuned and leak-free


Microplastics are a subcategory of plastic pollution. The small size of these contaminants makes them prevalent in all segments of the watershed. Defined as small pieces of plastic, less than 5 mm (0.2 inch) in length, microplastics can be found throughout the environment. Microplastics do not biodegrade, they break into smaller and smaller pieces, which cause them to accumulate and persist in the environment. A plastic cup left on the beach, ski resort, or park will breakdown into microplastic, and enter the ecosystem, it can then be introduced into the air via wind, or into a watershed via rain or snowmelt.

As part of ongoing watershed protection programs, the Tahoe Water Suppliers Association (TWSA) has worked in partnership with the Tahoe Environmental Research Center (TERC/UC Davis) and the Nevada Division of Environmental Protection (NDEP) to pro-actively study the presence of microplastics in the surface waters of Lake Tahoe.

The NTPUD’s Water Treatment Plant at the Tahoe Vista Recreation Area uses the best available technology to disinfect and filter source water before delivering it to customers. Although microplastics have been found in the waters of Lake Tahoe, their presence in drinking water sourced from Lake Tahoe is not a concern to the TWSA or the District.

More information on microplastics research is available here – https://ntpud.org/news/microplastics-in-lake-tahoe-the-drinking-water-perspective-tahoe-tap-remains-safe-and-healthy/

Dog Waste: Be #1 at picking up #2

Dog poop is not just an aesthetic issue, but a water quality issue. People have become concerned about the effects of accumulated dog waste on water quality, especially in Lake Tahoe. Dog waste, like any waste, may contain a variety of microbes which could cause diseases that can potentially be transmitted to humans through our water. A recent study conducted by scientists at University of Nevada Reno Cooperative Extension sheds light on the risks of water contamination from dog feces, especially during the colder months.

Invasive Species: Asian Clam/Quagga Mussels

Spreading invasive species in Lake Tahoe like Quagga Mussels, Zebra Mussels and New Zealand Mud Snails violates local, state, and federal laws and affects our water quality. Help us prevent these issues by learning about them, properly preparing your boat, and following inspection laws. Visit TahoeBoatInspections.com and TahoeKeepers.org for more information.


Phosphorus is one of the three key pollutants reducing Lake Tahoe’s clarity. Applying too much water, fertilizer, and pesticides on your lawns directly impacts Tahoe’s water quality and fuels algae growth. The Tahoe Regional Planning Agency (TRPA) recommends the use of phosphorus-free fertilizer. Read more about this issue and how to choose your fertilizer on the TRPA website.

Cigarette Butt Disposal Bin Project

The League to Save Lake Tahoe and the Tahoe Waters Suppliers Association (TWSA) are distributing cigarette butt collection canisters at key locations around Lake Tahoe. The aim of the Tahoe Cigarette Disposal Program is to reduce toxic chemicals from littered cigarette butts from leaching into the environment, to protect wildlife, and to reduce litter on Lake Tahoe’s shoreline. In 2018 more than 27,600 cigarette butts were collected in and around Lake Tahoe by the League and volunteers. It is time to change that drastic statistic.

UC Davis Tahoe Environmental Research Center

The UC Davis Tahoe Environmental Research Center annually produces the Tahoe: State of the Lake Report. The report summarizes data collected as part of the center’s ongoing, decades-long measurement programs, while also presenting research driven by important questions of the day. This includes how drought has impacted Tahoe’s forests, and the lake’s response to increasing levels of algae on the shoreline, climate change, and invasive species. It also takes a first look at what new technologies, including autonomous underwater vehicles, are finding in the deepest parts of the lake.