Frequently Asked Questions and Answers
What’s being done to clean up the lake?
The North Tahoe Public Utility District (NTPUD) has cleaned and disinfected the spill site as well as the adjacent parking lot, walkways, and beach areas that were impacted.
With regard to lake water quality, there are no common known practical methods to treat a large volume of lake water, especially in a water body as large as Lake Tahoe. Further, some of the concerning bacteria present in untreated sewage also naturally occur in the lake in lower concentrations. The best remedy to the water quality impacts is time. The elevated levels of bacteria, as a result of the sewer spill, begin to die off in the environment rapidly due to lack of nutrients and exposure to ultraviolet light from the sun. Concentrations typically return to naturally occurring levels in a matter of several days or a week.
In collaboration with the California Tahoe Conservancy and Placer County, the NTPUD is continuing restoration work at the spill site, including repair of the landscaping and public access areas.
How will it be determined that the water is safe for contact again?
Water quality samples are being taken daily from the Lake Tahoe shoreline at and near the spill site as well as areas outside the spill site. The laboratory analysis requires 24-hours to process.
Samples at each location identify the levels of bacteria in the form of total coliform, fecal coliform, and Escherichia coli (E. coli). The fecal coliform and E. coli levels in particular are associated with untreated sewage.
The elevated levels of bacteria, as a result of the sewer spill on Thursday, July 18, are expected to return to naturally occurring levels in the near future.
Officials are evaluating the results as they come in and the health advisory will be lifted after multiple observations show that the bacteria levels have returned to a more typical range for water contact and recreation.
What should I do if I came into contact with lake water in the advisory area?
Elevated fecal coliform bacteria in natural bodies of water like lakes can increase certain health risks. Contact with such water can lead to gastrointestinal illnesses (nausea, vomiting, diarrhea, and stomach cramps), skin infections, eye, nose, and ear infections, and potentially more serious illness.
To reduce the risk, Public Health recommends engaging in water activities outside the advisory area, avoiding swallowing impacted water, and showering with soap afterward if contact with impacted water occurs.
Please contact your healthcare provider if you begin experiencing any symptoms that are out of the ordinary for you.
Is it safe to swim and recreate on Lake Tahoe?
Yes – area beaches and shoreline outside of the health advisory zone are not at risk. Beaches in Kings Beach, Tahoe Vista, Tahoe City, and South Lake Tahoe are open to the public with no impact.
When and where was the sewer spill?
The spill occurred at 5074 North Lake Boulevard in Carnelian Bay, California at approximately 8:00 p.m. on Thursday, July 18th.
Who was responsible for the spill?
The spill was caused by a private contractor working on a Cal-Trans project to install a lighted crosswalk on Highway 28.
How can you be sure that local drinking water is safe?
The North Tahoe Public Utility District provides drinking water to 3,985 customers in North Lake Tahoe.
The NTPUD drinking water system in Carnelian Bay is supplied by a deep groundwater well, which is not directly connected to the lake and was not impacted by the spill.
The NTPUD’s primary water system, the Tahoe Main Water System, draws water from Lake Tahoe through a lake intake at the Tahoe Vista Recreation Area – which is outside the advisory zone and the area impacted by the spill.
Water entering the Tahoe Main Water System is processed through the District’s Water Treatment Plant, also located at the Tahoe Vista Recreation Area. The District’s Water Treatment Plant utilizes the best available technology to disinfect and filter water sourced from Lake Tahoe. Treatment includes chlorine and germicidal UV lights that inactivates any bacteria and microorganisms, as well as a micron filter that removes any debris such as microplastics larger than 25 microns (a piece of hair is 70 microns). The District also performs water sampling of the lake water and treated water to verify the District is supplying safe drinking water to our customers.
What if I have a private lake water intake and my own water system?
Private lakefront properties in the advisory area with their own lake intakes should be aware of these elevated bacteria levels and should contact Placer County Environmental Health with concerns about their drinking water.
What if I am a customer of Fulton Water Company or Agate Bay Water Company?
Customers of the two private water companies within the NTPUD District boundaries are supplied from water sourced outside the advisory area. Private water company customers are encouraged to contact their water provider for more information.