Featured Research

from universities, journals, and other organizations

Million-year-old groundwater in Maryland water supply

Date:
June 18, 2012
Source:
United States Geological Survey
Summary:
A portion of the groundwater in the upper Patapsco aquifer underlying Maryland is over a million years old. A new study suggests that this ancient groundwater, a vital source of freshwater supplies for the region east of Washington, DC and Baltimore, was recharged over periods of time much greater than human timescales.

A portion of the groundwater in the upper Patapsco aquifer underlying Maryland is over a million years old. A new study suggests that this ancient groundwater, a vital source of freshwater supplies for the region east of Washington, D.C. and Baltimore, was recharged over periods of time much greater than human timescales.

Related Articles


"Understanding the average age of groundwater allows scientists to estimate at what rate water is re-entering the aquifer to replace the water we are currently extracting for human use," explained USGS Director Marcia McNutt. "This is the first step in designing sustainable practices of aquifer management that take into account the added challenges of sea level rise and increased human demand for quality water supplies."

This new study from the USGS, the Maryland Geological Survey (MGS) and the Maryland Department of the Environment (MDE) documents for the first time the occurrence of groundwater that is more than one million years old in a major water-supply aquifer along the Atlantic Coast. The oldest groundwater was found in the deepest parts of the aquifer, but groundwater even in shallower parts of the aquifer is tens to hundreds of thousands years old.

Groundwater age indicates the length of time that a sample of water has been in the ground since infiltrating from the land surface. This study reveals that modern pumping in southern Maryland west of the Chesapeake Bay and on the Eastern Shore is tapping groundwater resources that have accumulated in the aquifer over multiple cycles of climate change and are not quickly recharging.

The analysis shows that water flowed from the land surface into the deep aquifer during cooler periods in earth's history, when glaciers covered much of the northeastern U.S. and sea level was about 125 meters lower than it is today. During warmer periods in earth's history, such as in modern times, higher sea levels slow recharge of fresh water to the aquifer, due to a lower gradient between the recharge and discharge areas.

Modern-day pumping rates have lowered water pressures and changed water chemistry, affecting the aquifer's ability to provide freshwater for drinking and other uses. Concerns over saltwater intrusion in some areas have led water managers to increasingly move groundwater production from shallower aquifers to the deeper upper Patapsco aquifer, which has caused groundwater levels to decline.

The findings are being used to help understand the patterns and rates of groundwater movement in the aquifers of the Coastal Plain. Such information will be used by the Maryland Department of the Environment to ensure that the management and use of the State's groundwater resources are being carried out to protect its long-term sustainability. The findings bring into focus that current users are withdrawing groundwater that was recharged eons ago and accentuate the need to review current water-supply management strategies and develop new tools and models to protect this valuable resource for the future.

There are relatively few aquifers in the world in which million-year-old groundwater has been documented, including the Nubian aquifer in the Sahara Desert, Canada's Alberta Basin, and the Great Artesian Basin in Australia

Aquifer sustainability is one of several priority topics currently being addressed by the USGS Groundwater Resources Program, the USGS National Research Program, and the USGS Cooperative Water Program.


Story Source:

The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. N. Plummer, J. R. Eggleston, D. C. Andreasen, J. P. Raffensperger, A. G. Hunt, G. C. Casile. Old groundwater in parts of the upper Patapsco aquifer, Atlantic Coastal Plain, Maryland, USA: evidence from radiocarbon, chlorine-36 and helium-4. Hydrogeology Journal, 2012; DOI: 10.1007/s10040-012-0871-1

Cite This Page:

United States Geological Survey. "Million-year-old groundwater in Maryland water supply." ScienceDaily. ScienceDaily, 18 June 2012. <www.sciencedaily.com/releases/2012/06/120618133145.htm>.
United States Geological Survey. (2012, June 18). Million-year-old groundwater in Maryland water supply. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2012/06/120618133145.htm
United States Geological Survey. "Million-year-old groundwater in Maryland water supply." ScienceDaily. www.sciencedaily.com/releases/2012/06/120618133145.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Clouds Fill Grand Canyon

Raw: Rare Clouds Fill Grand Canyon

AP (Jan. 29, 2015) For the second time in two months, a rare weather phenomenon filled the Grand Canyon with thick clouds just below the rim on Wednesday. (Jan. 29) Video provided by AP
Powered by NewsLook.com
Senate Passes Bill for Keystone XL Pipeline

Senate Passes Bill for Keystone XL Pipeline

AP (Jan. 29, 2015) The Republican-controlled Senate has passed a bipartisan bill approving construction of the Keystone XL oil pipeline. (Jan. 29) Video provided by AP
Powered by NewsLook.com
"Cloud Inversion" In Grand Canyon

"Cloud Inversion" In Grand Canyon

Reuters - US Online Video (Jan. 29, 2015) Time lapse video captures a blanket of clouds amassing in the Grand Canyon -- the result of a rare meteorological process called "cloud inversion." Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Why Researchers Say We Should Cut Back On Biofuels

Why Researchers Say We Should Cut Back On Biofuels

Newsy (Jan. 29, 2015) Biofuels aren&apos;t the best alternative to fossil fuels, according to a new report. In fact, they&apos;re quite a bad one. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins