Preliminary results confirm the presence of perchlorate in shallow groundwater along the Las Vegas Wash. Field work to date includes:. The next steps for AECOM are filling data gaps that were found after examining existing and recently collected data. Field work for this part of the investigation should begin in In January , the system began treating shallow groundwater associated with the construction of the Southern Nevada Water Authority's final two erosion control structures along the Las Vegas Wash.
Dewatering and treatment of the dewatered water is expected to continue until September More than 4, pounds of perchlorate were removed between January and May Downgradient Investigation - Frequently Asked Questions. Giardiasis may pose a serious health risk to individuals with severely suppressed immune systems. Giardiasis outbreaks occur more frequently in the northeast and northwest, possibly due to the extended winter season and low surface water temperatures.
Most community outbreaks occurred in water systems with minimum treatment to their surface water sources. A giardiasis outbreak usually occurs when conditions include low water temperatures, poor sanitation upstream, beaver colonies or other ground animals such as muskrat located near the water supply intake, and inadequate water treatment. One of the most effective safeguards against Giardiasis is ozonation, a water treatment process which uses ozone to eliminate biological organisms.
The Southern Nevada Water Authority's Alfred Merritt Smith and River Mountains water treatment facilities, which treat the majority of our water supply, incorporate ozonation into the treatment process. Perchlorate is a salt formed by the addition of oxygen molecules to chloride. It is used as an oxidizer in rocket propellants, fireworks and munitions, and also is naturally occurring in some fertilizers. Concentrations in the treated water currently average 0.
The sources of perchlorate in Lake Mead—and downstream in the Colorado River system—are two industrial complexes in the southeast portion of the Las Vegas Valley, where perchlorate was produced for industrial use. Groundwater contaminated with perchlorate traveled to the Las Vegas Wash through the shallow groundwater system and subsequently entered the lake.
To capture this water and prevent additional perchlorate from entering the Las Vegas Wash, the Nevada Division of Environmental Protection has overseen the installation of an interception system that uses wells to extract the contaminated water. This system has proven extremely effective, reducing the amount of perchlorate entering the Las Vegas Wash by approximately 90 percent.
Reverse osmosis units are generally effective at reducing perchlorate levels in drinking water to below detection limits. The Southern Nevada Water Authority encourages any customers with concerns about perchlorate-related health effects to consult their physician.
To learn more about perchlorate and our water supply, read the Water Quality Report. For general information about perchlorate, see the EPA's perchlorate fact sheet. Trihalomethanes THMs are disinfection byproducts created when chlorine used to disinfect water reacts with naturally-occurring organic and inorganic materials. The Southern Nevada Water Authority, which treats the valley's water supply, takes proactive measures to manage the formation of THMs during the water treatment process.
Southern Nevada's municipal water supply meets that health-based standard. Although some studies have indicated an association between elevated levels of THMs and adverse health effects among pregnant women, no causal relationship has been established. While science has not established a causal relationship between THMs and adverse health effects among pregnant women, the Water Authority advises consumers—particularly pregnant women—to call the EPA's Safe Drinking Water Hotline at about any concerns related to THMs.
Facts about our water. How does lead get into water? How can I minimize the potential of exposure to lead in tap water? What about copper? Water is considered "hard" when it contains a high level of dissolved minerals. There are several ways to reduce problems associated with hard water, including the use of: Dishwasher rinse aids Laundry detergents that contain water-softening agents Bath salts such as Epsom salts Lime- or mineral-dissolving household cleaners Deposits on fixtures and countertops can be prevented by wiping surfaces dry.
Water softeners Household systems reduce the hardness of the water by replacing calcium and magnesium with sodium or potassium, depending on the type of softener. Learn more about household water softeners. Why is Southern Nevada's water system fluoridated? Fluoride levels considerably lower than limits Low levels of fluoride, about 0. Proper medication disposal Old or unused medications should never be flushed down the toilet, as this is a way that drugs can enter the water supply.
The Southern Nevada Health District suggests these methods for the proper disposal of medications: Dump pills in a sealable bag. Crush the pills with a heavy object. Although most perchlorate is man-made, it can also be naturally occurring. Like salt, perchlorate dissolves easily in water.
Perchlorate is known to interfere with thyroid function, and is considered an environmental contaminant. Perchlorate was detected in the Lower Colorado River in Located upstream from the detection point in the Las Vegas Wash were two perchlorate manufacturers.
It was ultimately determined that perchlorate was entering the Las Vegas Wash through contaminated groundwater and surface water stemming from Kerr-McGee, a manufacturing facility near Henderson, Nevada. After the sources of perchlorate had been identified, remediation plans were enacted to begin removing perchlorate from affected groundwater and surface water. The Nevada Environmental Response Trust NERT , owner of the property where the Kerr McGee facility was located, currently extracts perchlorate-contaminated groundwater and treats it in aboveground tanks that biologically remove the perchlorate from the groundwater.
NERT is currently field-testing a variety of different technologies to determine what will be the most effective solution for the future treatment of perchlorate-contaminated groundwater. As of January 1, , remediation activities in Southern Nevada have resulted in the removal of more than 6, tons of perchlorate from the environment.
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