Revision History for U.S. Geological Survey Scientific Investigations Report 2018–5170

By John W. Clune and Charles A. Cravotta III

Drinking Water Health Standards Comparison and Chemical Analysis of Groundwater for 72 Domestic Wells in Bradford County, Pennsylvania, 2016

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Posted April 19, 2019
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Revised and reposted April 23, 2019, Version 1.1

In the Abstract (page 2, first full paragraph, third sentence), a change was made from 
The majority of Bradford County well-water samples, including the samples with the highest chloride 
concentrations, have chloride/bromide ratios that indicate predominantly anthropogenic sources of chloride, 
such as road-deicing salt or septic effluent.

to

Most of Bradford County well-water samples have chloride concentrations less than 20 mg/L, and those with 
higher chloride concentrations have chloride/bromide ratios that indicate anthropogenic sources (such as 
road-deicing salt and septic effluent) or brine. 

In the Summary and Conclusions (page 31, right-hand column, second paragraph, third sentence), the same 
change was made as above. 


Revised and reposted on May 30, 2019, version 1.2 
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In the Introduction (page 5, first full paragraph, first sentence), a change was made from 

Land use is predominately agricultural, consisting mainly of pasture/hay (35.9 percent) and cropland (17.5 percent). Forested areas (32.8 percent) are 
mostly on private land except for a small portion of Pennsylvania state forest, one state park, and several state game lands (fig. 1B) (Multi-Resolution 
Land Characteristics Consortium, 2014). During the summer of 2016, Bradford County was second among all counties in the state for the most horizontal 
unconventional gas wells drilled (n=1,339; Pennsylvania Department of Environmental Protection, 2017), and the related infrastructure (well pads, pipelines, 
and so forth) has become a relatively recent part of the landscape. Wetland and water resources compose 4.0 percent and 1.5 percent of the landscape, 
respectively. The remaining land area is developed/residential land (7.5 percent) with a largely rural population of 62,622 recorded in 2010 
(U.S. Census Bureau, 2011).

to

Land use is predominately forested (56.1 percent), mostly on private land except for a small portion of Pennsylvania state forest, one state park, and s
everal state game lands. Agricultural land use consists mainly of pasture/hay (23.5 percent) and cropland (11.4 percent; fig. 1B) (Multi-Resolution 
Land Characteristics Consortium, 2014). During the summer of 2016, Bradford County was second among all counties in the state for the most horizontal 
unconventional gas wells drilled (n=1,339; Pennsylvania Department of Environmental Protection, 2017), and the related infrastructure (well pads, pipelines, 
and so forth) has become a relatively recent part of the landscape. Wetland and water resources compose 2.67 percent and 0.98 percent of the landscape, 
respectively. The remaining land area is developed/residential land (4.95 percent) with a largely rural population of 62,622 recorded in 2010 
(U.S. Census Bureau, 2011).