ABSTRACT
Water samples collected from 1986-98 from 912 wells in the Piedmont of southeastern Pennsylvania were analyzed for radon-222 activity. Radon-222 activities ranged from 49 to 53,000 picoCuries per liter (pCi/L); the median activity was 1,400 pCi/L. The proposed U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) for radon-222 is 300 pCi/L, and the proposed Alternative Maximum Contaminant Level (AMCL) is 4,000 pCi/L. Water from 89 percent of sampled wells exceeds the MCL, and water from 16 percent of sampled wells exceeds the AMCL. The distribution of radon-222 activities differed among rock types with elevated activities most frequently occurring in ground water in schists and quartzites. The median radon-222 activity was highest for water samples from wells in schist (2,490 pCi/L) with 94 percent and 27 percent of samples exceeding the MCL and AMCL, respectively. The median radon-222 activity for water samples from wells in quartzites was 2,300 pCi/L with 96 percent and 27 percent of samples exceeding the MCL and AMCL, respectively. The median radon-222 activity was lowest for water samples from wells in carbonate rocks (630 pCi/L) with 74 percent and 4 percent of samples exceeding the MCL and AMCL, respectively.
Citation:
Sloto, R.A., and Senior, L.A., 2000, Radon-222 activities in the ground water of the Piedmont Physiographic Province, southeastern pennsylvania [abstract]: Geological Society of America Abstracts with Programs, Northeastern Section, v. 32, no. 1, p. A-75.

Return to the USGS Chester County Water Resources Page
Return to the USGS Southeastern Pennsylvania Radionuclide Studies Page
![]()
Return to the Water Resources of Pennsylvania
Home Page 
or go directly to:
![]()
The URL for this page is http://pa.water.usgs.gov/malvern/radon_GSA_abstract.html
Please note our privacy statement
and disclaimer
Accessibility
Answers to many common questions can be found on our
Frequently Asked Questions (FAQ)
page. Please direct content comments
or questions to:
| Information Specialist U.S. Geological Survey 215 Limekiln Road New Cumberland, PA 17070-2424 |
Phone: (717) 730-6916 FAX: (717) 730-6997 Email: is_pa@usgs.gov |
|
or contact: | |
| Director, USGS Pennsylvania Water Science Center U.S. Geological Survey 215 Limekiln Road New Cumberland, PA 17070-2424 |
Phone: (717) 730-6960 FAX: (717) 730-6997 Email: dc_pa@usgs.gov |