The USGS and the Centers for Disease Control and Prevention are examining the potential effects of droughts on the arsenic hazard in private well water across the Nation.
Together, we are using existing models that can be modified with drought-influenced data, such as conditions that occurred in August of 2012, on recharge and precipitation to assess the effects on the probability of having high-arsenic wells. The estimates can then be used to assess potential changes in the number of domestic well users exposed to high arsenic and examine regional effects.
Specifically, this study’s objectives are to:
- Estimate the probability of having high arsenic in domestic wells under different drought scenarios; and
- Estimate the change in the number of domestic well users exposed to high-arsenic well water due to drought conditions.
Below are FAQ associated with this project.
What determines if a well will go dry?
A well is said to have gone dry when water levels drop below a pump intake. This does not mean that a dry well will never have water in it again, as the water level may come back through time as recharge increases. The water level in a well depends on a number of things, such as the depth of the well, the type (confined or unconfined) of aquifer the well taps, the amount of pumping that occurs in...
What causes drought?
A drought is a period of drier-than-normal conditions that results in water-related problems. The amount of precipitation at a particular location varies from year to year, but over a period of years the average amount is fairly constant. In the deserts of the Southwest, the average precipitation is less than 3 inches per year. In contrast, the average precipitation in the Northwest is more than...
When does a drought begin and end?
The beginning of a drought is difficult to determine. Several weeks, months, or even years might pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in...
Where can I get my well water tested?
Some counties offer free well water testing, so check with your county first. If they don't, use this EPA website to find a list of state-certified laboratories in your area that do water testing, or contact your county or state health department or your State Certification Officer for assistance. Prices will vary depending on the laboratory and the test(s), but most people consider the cost to be...
Where in the Nation are droughts or very low flows occurring now? How can I see these sites on a map and get to the data?
To view the USGS streamflow information on drought, see the drought map on our WaterWatch site, which shows below-normal, 7-day average streamflow compared to historical streamflow for the United States. Links to additional maps and drought data are listed on the USGS Drought website and the National Integrated Drought Information System (NIDIS).
- Overview
The USGS and the Centers for Disease Control and Prevention are examining the potential effects of droughts on the arsenic hazard in private well water across the Nation.
Together, we are using existing models that can be modified with drought-influenced data, such as conditions that occurred in August of 2012, on recharge and precipitation to assess the effects on the probability of having high-arsenic wells. The estimates can then be used to assess potential changes in the number of domestic well users exposed to high arsenic and examine regional effects.
Specifically, this study’s objectives are to:
- Estimate the probability of having high arsenic in domestic wells under different drought scenarios; and
- Estimate the change in the number of domestic well users exposed to high-arsenic well water due to drought conditions.
- Publications
- FAQ
Below are FAQ associated with this project.
What determines if a well will go dry?
A well is said to have gone dry when water levels drop below a pump intake. This does not mean that a dry well will never have water in it again, as the water level may come back through time as recharge increases. The water level in a well depends on a number of things, such as the depth of the well, the type (confined or unconfined) of aquifer the well taps, the amount of pumping that occurs in...
What causes drought?
A drought is a period of drier-than-normal conditions that results in water-related problems. The amount of precipitation at a particular location varies from year to year, but over a period of years the average amount is fairly constant. In the deserts of the Southwest, the average precipitation is less than 3 inches per year. In contrast, the average precipitation in the Northwest is more than...
When does a drought begin and end?
The beginning of a drought is difficult to determine. Several weeks, months, or even years might pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in...
Where can I get my well water tested?
Some counties offer free well water testing, so check with your county first. If they don't, use this EPA website to find a list of state-certified laboratories in your area that do water testing, or contact your county or state health department or your State Certification Officer for assistance. Prices will vary depending on the laboratory and the test(s), but most people consider the cost to be...
Where in the Nation are droughts or very low flows occurring now? How can I see these sites on a map and get to the data?
To view the USGS streamflow information on drought, see the drought map on our WaterWatch site, which shows below-normal, 7-day average streamflow compared to historical streamflow for the United States. Links to additional maps and drought data are listed on the USGS Drought website and the National Integrated Drought Information System (NIDIS).
- Partners