. Author manuscript; available in PMC: 2018 May 1.

Published in final edited form as: Am Econ Rev. 2017 May;107(5):522–525. doi: 10.1257/aer.p20171133

Table 2. Water Quality Impacts of Well Pad Spudding.

	d ≤ 0.5 km	d ≤ 1 km	d ≤ 1.5 km	d ≤ 2 km
Panel A. By distance to well pad
Pads in “d” km	0.0269 (0.0106)	0.0149 (0.00863)	0.000516 (0.00655)	0.00492 (0.00584)
Pads in 10 km	−0.000187 (0.000248)	−0.000313 (0.000287)	−0.000111 (0.000259)	−0.000366 (0.000319)
Observations	54,809	54,809	54,809	54,809
Panel B. By elevation to intake
Downhill pads in “d” km		0.00202 (0.0227)	−0.00643 (0.00895)	−0.000847 (0.00560)
Uphill pads in “d” km	0.0264 (0.0104)	0.0155 (0.00803)	0.00163 (0.00710)	0.00648 (0.00739)

Notes: Each column is a separate regression. Observations = 54,809 for each of the weight regressions reported. For panel B, pads up- and down-hill within 10 km are included but not shown. Robust standard errors in parentheses are clustered at the CWS level. The dependent variable is log(SGD chemicals).