Groundwater age dating using tritium Dating bi filipina
Ground-water resources provide about one-third of the water used for domestic, commercial and industrial purposes in the Anchorage metropolitan area and are the sole sources of water for industries and residents outside Anchorage.
In 1997, a study of the Cook Inlet Basin was begun as part of the U. Geological Survey's National Water-Quality Assessment Program. Samples of ground water were collected from 35 existing wells (Fig.
Groundwater ages of the medium-depth groundwater ranged from 3.5–25,790 a.
Groundwater is relatively young in most of the piedmont area, although two high-age zones (with ages 20,000 a) exist in the center of the plain.
This ground water is vulnerable to contamination from the land surface, and many contaminants in the water would follow the same paths and have similar travel times from recharge areas to points of use as the chemical substances analyzed in this study.
The effects of contamination may not be seen for several years after a contaminant is introduced into the groundwater system.
Ground-water age refers to the time elapsed since the water entered the saturated zone and was isolated (through additional recharge) from the atmosphere.
The travel time of a chemically conservative substance depends primarily on the velocity of ground water through the aquifer, which in turn depends on the hydrologic characteristics of the aquifer system.
Over the last 50 years, human activities have introduced a large number of substances into the air and water.
Compounds that move readily through the environment relatively unchanged physically or chemically can help determine when the water was recharged, the areas of water recharge, the flow path, and the rate of water movement through an aquifer system.
Approximately 350,000 people, more than half of Alaskas population, reside in the basin, mostly in the Anchorage area.
However, rapid growth is occurring in the Matanuska Susitna and Kenai Peninsula Boroughs to the north and south of Anchorage.
The ages or travel times calculated assume no dilution by mixing or delay by interaction with aquifer materials, which are common processes for contaminants moving with ground water.